NATIONAL LIBRARY OF MEDICINE 7th & Independence Ave., S. VL Washington 25, D. G, x ANATOMY OF THE AETEEIBS OF THE HUMAN BODY. WITH THE DESCRIPTIVE ANATOMY OF THE HEART. ANATOMY OF THE ARTERIES OF THE HUMAN BODY, Jwmjrftfoe nth Surgical, WITH THE DESCRIPTIVE ANATOMY OF THE- HEART; JOHN HATCH POWER, M.D. FELLOW, AND MEMBER OF COUNCIL, OF THE ROYAL COLLEGE OF SURGEONS ; PROFESSOR OF DESCRIPTIVE AND PRACTICAL ANATOMY IN THE ROYAL COLLEGE OF SURGEONS ; SURGEON TO THE CITY OF DUBLIN HOSPITAL, ETC. Wtify lUnstrationsV „ \ „ B. WILLS RICHARDSON, F.R.C.S.I. ' EXAMINER IN THE ROYAL COLLEGE OF SURGEONS, SURGEON TO THE ADELAIDE HOSPITAL, ETC. DUBLIN : FANNIN AND CO. GRAFTON STREET. BOOKSELLERS TO THE KOTAL COLLEGE OF SURGEONS. LONDON: LONGMAN AND CO.; SIMPKIN AND CO. MDCCCLX. DUBLIN: PRINTED BT R0BE11T CHAPMAN TEMPLE LANE, DAME STREET. PREFACE. The present work has been undertaken chiefly with the view of assisting the student whilst engaged in the study of Practical Anatomy, and of affording him such practical information in connection with the Anatomy of the Arterial System as may be of advantage to him long after his studies have been completed. For the purpose of effecting these desirable objects, I have endeavoured to simplify as much as possible the anatomical details, and to bring together such material facts in relation to the operations upon the principal arteries of the body, as may lead to correct conclusions relative to the treatment of the various accidents and diseases to which these vessels are exposed. The recent alterations which have been made by some of the licensing bodies in these kingdoms have rendered their examinations more demonstrative in their character than heretofore ; and I trust it will be found, that, in the arrangements which I haye adopted, the student will 6 VI PREFACE. receive such assistance in this respect as the improved mode of examination would appear to render necessary. I have not overlooked the fact, that there are many practitioners, particularly those in rural districts, who do not possess any opportunity of refreshing their memories upon anatomical points by actual dissection ; and I am not without hope that to such, the present volume may afford some useful hints as to the relations of those blood vessels which, from time to time, may become the subjects of their operations. The Illustrations have been executed from drawings made expressly for the work by Mr. B. Wilis Richardson, Examiner in Anatomy and Physiology in the Royal College of Surgeons, and late Demonstrator of Anatomy in the Carmichael School of Medicine. The elevated position to which this gentleman has been raised in the College, and which he continues to fill with so much honor, sufficiently indicates his reputation as an Anatomist. The accurate and beautiful plates of Tiedeman and Cloquet, of Professor Quain and Maclise have been rendered available for the illustrated portion of the work. I cheerfully acknowledge my obligations to the labours of the late Professor Harrison, Professor Alcock, and particularly to those of my former colleague in the Carmichael School of Medicine, the late Dr. Flood. In the year 1850 I brought out a new edition of this last gentleman's work upon the arteries, which has for some time since been out of print, but of which the principal part has been embodied in the present work. PREFACE. VII The greater number of the illustrations have been executed by Mr. Oldham of this city, and the remainder by Messrs. Butterworth and Heath, of London. It would be superfluous to say any thing here in praise of Mr. Oldham as an artist ; his talents are so well known and valued as to render such commendation upon my part unnecessary. Messrs. Butterworth and Heath are also well known as artists of considerable merit and high standing in their profession. JOHN HATCH POWER. 95, Harcourt-street, Dublin, October, 1860. 6 2 CONTENTS. Mr. Adam's Views . . . . . .17 Mr. Hunter's Views 17 Functions of the Tricuspid Valve . . . .17 Valvular Septum of Lieutaud, of Right Ventricle . 16 Tricuspid Valve . . . . . . .16 Chorda? Tendineae . . . . . . .16 Carnea? Columnar . . . . . . .15 Infundibulum . . . . . . .15 Right Ventricle 15 Left Auricle . . . . . . . .14 Vena; Thebesians . . . . . . .12 Openings of the Vena? Cavse 12 Lesser Eustachian Valve . . . . .11 Great Eustachian Valve . . . • .11 Aunulus Vieussenii 11 Foramen of Galen or Botal 10 Fossa Ovalis 10 Tuberculum Loweri . . . . . .10 Right Auricle 9 External Surface 4 General Description of the Heart .... 4 Pericardium . ...... 2 Preliminary Directions 1 Descriptive Anatomy of the Heart .... 1 PREFACE iii X CONTENTS. Descriptive Anatomy of the Heart (continued). Mr. King's Safety Valve 18 Left Ventricle 20 Mitral Valve of Vesalius 20 Valvular Septum of Lieutaud, of Left Ventricle . . 20 Zonae Tendinosse 21 Opinions of Bouillaud . . . . . .21 Relative Capacities of the Cavities of the Heart . . 22 Structure of the Heart ...... 24 Muscular fibres of the Heart ..... 24 Mr. Searle on the arrangement of the Muscular fibres of the Heart 26 Endocardium 29 Arteries of the Heart . . . . . .29 Posterior or right Coronary Artery .... 30 Anterior or left Coronary Artery .... 30 Veins of the Heart ... .... 31 Greater and Lesser Coronary Veins . . . .31 Vena Galeni ........ 31 Nerves of the Heart . . . . . . .32 Superior Cardiac Nerve ...... 32 Middle Cardiac Nerve 32 Inferior Cardiac Nerve ...... 32 Cardiac Plexuses ....... 32 Great Cardiac Plexus . .• . . . .33 Superficial or Anterior Plexus 33 Deep or Posterior Plexus ...... 33 Cardiac Ganglion of Wrisberg . . . . .33 Coronary Plexuses ....... 33 Lymphatics of the Heart ....... 34 Pulmonary Artery 34 Ductus Arteriosus 34 Right Pulmonary Artery . . . . . .36 Left Pulmonary Artery ...... 36 Dr. Hope on the position of the Heart and its great Vessels 36 CONTENTS. XI Aorta . 38 Arch of Aorta 88 Anterior or Ascending portion of the Arch of Aorta . 38 Connection of the Aorta with the Left Ventricle . . 39 Sinuses of Valsalva . . . . . .41 Great Sinus of the Aorta . . . . .41 Middle Portion of the Arch of the Aorta. . . .41 Posterior or Descending portion of the Arch of the Aorta 42 Practical Deductions ...... 45 Development of the Aorta 4G Branches of the Arch of the Aorta . . . .46 Arteria Innominata 47 Veins related to the Arteria Innominata . . .48 Ligature of the Arteria Innominata, with tabular view 50 Professor Porter's case . . . . . .51 Modes of Operation 51 Common Carotid Arteries 54 First or inferior Stage of the right Common Carotid . 54 First or inferior Stage of the left Common Carotid . 55 Veins related to the Thoracic portion of the left Carotid 57 Second or superior Stage of the Common Carotid Artery 57 Veins of the Neck . . . . . . .59 Ligature of the Common Carotid Artery . . .'62 The Hunterian operation . . . . . . 62 Brasdor and Dessault's operation .... 62 Wardrop's operation ....... 62 Operation in case of wound or ulceration ... 63 Hebenstreit's case 63 Mr. Abernethy's case ...... 63 Mr. Ellis' case 63 Sir A. Cooper first tied the Artery for Aneurism . . 63 Modes of the operation ...... 64 Operation, hi its inferior Stage . . . . .65 XII CONTENTS. Common Carotid Artery (continued). Sedillot's operation . . . . . . .66 Operation, in its superior Stage . . • . .66 Bifurcation of the Common Carotid .... 67 External Carotid Artery 67 Ligatnre of the External Carotid Artery . . .69 Branches of the External Carotid .... 69 Superior Thyroid Artery . . . . . .70 Branches of the Superior Thyroid Artery . . .70 Lingual Artery ....... 72 Branches of the Lingual Artery . . . .74 Accompanying Veins . . . . . .75 Operation of Tying the Lingual Artery . ... 75 Wounds of the Eanine Artery ..... 76 Facial Artery 76 Facial Vein . 78 Branches of the Facial Artery . . . .79 Occipital Artery ....... 83 Branches of the Occipital Artery .... 84 Posterior Auricular Artery . . . .86 Pharyngea Ascendens Artery . . . . .87 Branches of Pharyngea Ascendens Artery . . .87 Transversalis Faciei Artery . . . . .87 Superficial Temporal Artery ..... 88 Branches of the Superficial Temporal Artery . . 88 Internal Maxillary Artery ..... 90 Branches of the Internal Maxillary Artery ... 92 Internal Carotid Artery . . . . .99 Branches of the Internal Carotid Artery . . . 102 Ophthalmic Artery 103 Branches of the Ophthalmic Artery .... 103 Cerebral Branches of the Internal Carotid Artery . 110 Rete Mirabile of Galen 112 CONTENTS. XIII Subclavian Arteries 113 Ligature of the Subclavian Artery in the first Stage . 118 Tabular View of Operation 119 Professor Colles' case . 119 Mr. Hayden's case . . . • ¦ .119 Mr. O'Reilly's case ...... 122 Mode of Performing the Operation .... 125 Ligature of Left Subclavian in its first Stage . . 126 Dr. Rodgers' case 126 Ligature of Subclavian Artery in its second Stage . 129 Ligature of Subclavian Artery in its third Stage . 130 Application of the Distal Ligature on the Subclavian and Carotid Arteries . . . . .132 Mr. Wardrop's Operation 133 Mr. Wickham's Operation 134 Dr. Hobart's Operation ..... 134 Branches of the Subclavian Artery . . . .136 Vertebral Artery . . . . : .136 Branches of the Vertebral Artery .... 139 Basilar Artery 141 Branches of the Basilar Artery .... 141 Circle of Willis 142 Internal Mammary Artery ..... 144 Branches of the Internal Mammary Artery . . 145 Thyroid Axis 146 Branches of the Thyroid Axis . . . .148 Cervicalis Profunda Artery * . . . . .151 Superior Intercostal Artery ..... 152 Axilla 152 Axillary Artery 156 Ligature of the Axillary Artery . . . .158 Ligature of Axillary Artery in its first Stage . . 158 Mr. Hodgson's Method 158 Manec's Method 160 CONTENTS. XIV Axillary Artery (continued). Ligature of Axillary Artery in its second Stage . 161 Ligature of Axillary Artery in its third Stage . .161 Rupture or Laceration of Axillary Artery . . 162 Mr Adams' case ....... 162 Branches of the Axillary Artery . . . .165 Acromial or Thoracica Acromialis Artery . . .165 Thoracica Suprema Artery 166 Thoracica Alaris Artery . . . . .166 Thoracica Inferior, or External Mammary Artery . 166 Infra or Subscapular Artery . . . . .167 Posterior Circumflex Artery . . : . .167 Anterior Circumflex Artery 168 Scapular Anastomosis ...... 168 Veins of the Arm and Fore-arm .... 170 Venesection . . . . . . .171 Aneurismal Varix ....... 172 Varicose Aneurism 172 Brachial Artery 172 Brachial Nerves . . . . . . .173 Ligature of the Brachial Artery . . . .175 Aneurisms of the Brachial Artery . . . .175 Treatment of the various Forms of Aneurism of the Brachial Artery . . . . . .177 Compression of the Brachial Artery . . .178 Modes of Operation . . . . . .181 Branches of the Brachial Artery . . . .184 Superior Profunda Artery . . . . .184 Arteria Nutritia . . . . . . .185 Inferior Profunda Artery 185 Anastomotic Artery . . . . . .186 Muscular Branches 186 Ulnar Artery 186 Branches of the Ulnar Artery 187 CONTENTS. XV Ulnar Artery (continued). Anterior Ulnar Recurrent Artery . . . .187 Posterior Ulnar Recurrent Artery . . . .187 Common Interosseal Artery . . . . .188 Muscular Branches . . . . . .189 Anterior Carpal Branch . . . . . . 189 Posterior Carpal Branch . . . . . .189 Communicans Profunda Artery . . . 190 Superficial Palmar Artery . . . . .190 Superficial Palmar Arch and Branches . . .191 Operation of Tying the Ulnar Artery . . . 192 Radial Artery 193 Branches of the Radial Artery . . . . .196 Radial Recurrent Artery . . . . .196 Muscular Branches . . . . . .196 Superficialis Volte 196 Anterior Carpal Artery 196 Posterior Carpal Artery . . . . .196 Dorsalis Pollicis 198 Metacarpal Artery . . . . . . .198 Radialis Indicia Artery ...... 198 Princeps Pollicis Artery 198 Palmaris Profunda Artery . . . . .198 Deep Palmar Arch . . . . . .199 Ligature of the Radial Artery 200 Descending Aorta 200 Thoracic Aorta 202 Branches of the Thoracic Aorta . . . .203 Abdominal Aorta 206 Ligature of the Abdominal Aorta . . . .207 Tabular View of Operation . . . . .208 Sir A. Cooper's case 208 Mr. James's case 209 CONTENTS. XVI Abdominal Aofta (continued). Dr. Murray's case 210 Dr. Monteiro's case 215 Mr. South's case 216 Branches of the Abdominal Aorta . . . .217 Cceliac Axis . ...... 217 Gastric, or Coronaria Ventriculi Artery . . .218 Hepatic Artery . . . . . . .218 Circulation of the Blood in the Liver . . . 221 Umbilical Vein in the Foetus 222 Vena Porte in the Foetus 222 Source of the Biliary Secretion 223 Kiernan's Observations on the Liver . . . .223 Todd and Bowman's Opinions .... 227 Splenic Artery 228 Structure of the Spleen 228 Superior Mesenteric Artery ..... 230 Branches of the Superior Mesenteric Artery . . 230 Inferior Mesenteric Artery . . . . .233 Branches of the Inferior Mesenteric Artery . . 233 Proper Phrenic Arteries ..... 236 Middle Capsular Arteries . . ... .236 Renal Arteries . . . . . . .238 Renal Veins 238 Arrangement of the Vessels in the Kidney . .210 Spermatic Arteries . . . . . .242 Lumbar Arteries ....... 245 Middle Sacral Artery 246 Common or Primitive Iliac Arteries .... 246 Ligature of the Common Iliac Artery . . . 249 Mr. Mott's case 249 Sir P. Crampton's case ...... 252 Mr. Hey's case 252 Internal Iliac Artery 253 Internal Iliac Artery in the Foetus .... 254 CONTENTS. XVII Internal Iliac Artery (continued). Ligature of the Internal Iliac Artery . . .254 Dr. Steven's and Mr. Atkinson's cases . . . 255 Mr. White's case 255 Branches of the Internal Iliac Artery . . .256 Glutseal Artery 256 Operation of Tying the Gluteal Artery . . . 257 Mr. Lizars' method ...... 259 Mr. Carmichael's case ...... 252 Sciatic, or Ischiatic Artery ..... 260 Branches of the Sciatic or Ischiatic Artery . . . 261 Obturator Artery 262 Branches of the Obturator Artery .... 263 Anatomy of the Ano-Perineal Region .... 264 Lateral Operation for Lithotomy .... 276 Internal Pudic Artery ...... 280 Branches of the Internal Pudic Artery . . . 283 External Hemorrhoidal Artery . . . .283 Long Perineal Artery ...... 283 Transverse Artery of the Perineum . . . .284 Artery of the Bulb 284 Artery of the Corpus Cavernosum . . . .284 Dorsal Artery of the Penis 286 Ilio Lumbar Artery . . . . .288 Lateral Sacral Artery 289 Middle Hemorrhoidal Artery 290 Vesical Artery 290 Umbilical Artery 291 Uterine Artery 291 Vaginal Artery 291 External Iliac Artery . . . .' . .291 Ligature of the External Hiac Artery . . . 292 Mr. Abernethy's operation 292 Sir A. Cooper's operation .' . . . .293 Branches of the External Iliac Artery . . .297 XVIII CONTENTS. External Iliac Artery (continued). Epigastric Artery . . . . . . .297 Internal Circumflexa Ilii Artery . . . .298 Femoral Artery 299 Femoral Vein ....... 306 Operations on the Femoral Artery . . . .306 Professor Porter's Operation 307 Compression on the Femoral Artery . . . .311 Mr. Todd's cases 311 Mr. M'Coy's case 312 Dr. Hutton's case . . . . . . .312 Dr. Cusack's case . . . . . . .313 Dr. Bellingham's cases . . . . . .314 Branches of the Femoral Artery . . . .315 Superficial Epigastric Artery . . . . .315 External Pudic Arteries 316 Superficial Circumflexa Ilii Artery . . . .316 Muscular Branches . . . . . .316 Anastomotica Magna Artery . . . . .316 Profunda Femoral Artery , . . . 317 External Circumflex Artery . . . . .317 Internal Circumflex Artery . . . . .318 Perforating Arteries ...... 321 Popliteal Space 322 Popliteal Artery 325 Ligature of the Popliteal Artery .... 326 Branches of the Popliteal Artery . . . .328 Articular Arteries 328 Anterior Tibial Artery 330 Ligature of the Anterior Tibial Artery . . . 332 Branches of the Anterior Tibial Artery . . . 332 Tibial Recurrent 333 CONTENTS. XIX Anterior Tibial Artery (continued). Muscular Branches . . . . . .333 Internal Malleolar Artery . . . . .333 External Malleolar Artery . . . . . 334 Tarsal Artery . . . . . .334 Metatarsal Artery 334 Dorsalis Pollicis 335 Ramus Communicans ...... 335 Posterior Tibial Artery 335 Ligature of the Posterior Tibial Artery . . .337 Branches of the Posterior Tibial Artery . . . 338 Muscular Arteries 338 Nutritious Artery 338 Peroneal Artery 338 Ligature of the Peroneal Artery . . . .339 Internal Plantar Artery ...... 341 Exterual Plantar Artery ...... 341 Branches of the External Plantar Artery . . . 343 Some of the Principal Varieties or Anomalies of the Arteries 345 ERRATUM. Page S86, Fig. 57, first line of description, for " Abductor" read " Adductor." ANATOMY OF THE HEART AND ARTERIES. DESCRIPTIVE ANATOMY OF THE HEART. PRELIMINARY DIRECTIONS. For the purpose of exhibiting the heart contained within its envelope the pericardium, together with the great vessels connected with it, particularly the aorta, the student is advised, in the first instance, to make a longitudinal incision through the abdominal parietes of about six inches in length, the centre being situated at the umbilicus : the bifurcation of the abdominal aorta should then be exposed, and a full sized pipe of the injecting apparatus inserted from below upwards into this vessel, about two inches above the origin of the common iliac arteries ; the injection should then be directed upwards, towards the heart. By this method the thoracic aorta, the arch of the aorta, its relation to the sternum, together with its other numerous important relations, will be best seen, whilst the arteries of the head, neck, and upper extremities will be much better filled than if the subject were injected from the ordinary situation, the arch of the aorta. The following dissection should now be performed : a perpendicular incision should be made, commencing from below the centre of the clavicle, and passing across the second, third, fourth, fifth, sixth and seventh ribs of B 2 PERICARDIUM. the left side : these bones should then be sawn through, a little in front of their centres, and the cartilage of the first rib of the same side divided. A second perpendicular incision should next be made through the integument covering the sternum, and then through the bone, keeping a little to the right side of the middle line. The lower extremities of these two incisions should now be connected by means of an oblique incision, and the parts included within them should be next raised off carefidly from below upwards, and then forcibly turned backwards upon the front of the neck. Whilst making this dissection, the soft parts lying behind the divided portions of the ribs and sternum should be carefully detached from these bones. The mammary artery is particularly liable to injury in this stage of the dissection. By adopting the plan now recommended, the student will be able to expose the pericardium, and to observe its relation to the parietes of the thorax, whilst the relations of the arch of the aorta, the proximity of this vessel to the right side of the sternum, and to the cartilage of the second rib, at its junction with the former bone, will attract his attention. The same plan of dissection may afterwards be pursued at the right side, with this difference, that the cartilage of the first rib should not be disturbed, in order that the dissection of the lower portion of the neck at that side, together with the dissection of the arteria innominata, may be pursued with advantage. THE PERICARDIUM. The pericardium, properly speaking, is a specimen of what Bichat calls a fibro-serous membrane, consisting of two layers of membrane, an external or fibrous, and an internal or serous layer. It is the immediate envelope of the heart, and of certain portions of the great vessels entering into and issuing from it. Its form is somewhat conoid; the apex corresponds to the large vessels in PERICARDIUM. 3 immediate connexion with the heart, in which situation the fibrous layer of the sac may be seen extended over them, and identified with their external tunic : the base may be seen resting on the cordiform tendon of the diaphragm, to which it adheres so firmly in the adult as to be with great difficulty separated from it ; it also rests on a small triangular portion of the fleshy fibres of the diaphragm, to the left of the tendon, from which it may very easily be separated. In the foetus the pericardium is but loosely connected with the tendon and fleshy fibres of the diaphragm. The anterior surface of the pericardium is covered by the thymus gland in the foetus, and in the adult by a considerable quantity of loose areolar tissue, which occupies the situation of the thymus gland ; by the internal and anterior portion of each lung and pleura, and by the sternum : and inclining towards the left side inferiorly, we find lying in front of it also the cartilages of the fourth, fifth, sixth and seventh ribs. The sides of the pericardium are over-lapped by the lungs, and are covered by the pleurae, the phrenic nerve being interposed at the left, and thrown more anteriorly, so as to bend over the pericardium at a point corresponding to the apex of the heart. Its posterior surface lies in front of the posterior mediastinum and the parts contained within this region, more particularly the oesophagus and descending aorta. An incision may now be made through the anterior part of this envelope, when its internal or serous layer will be exposed : this consists of two portions,—the one fining the inner surface of the fibrous layer, and the other, with which the former is perfectly continuous, surrounding the heart. The continuity of these two portions of the serous membrane may be demonstrated, in. the first place, by tracing that lining the inner surface of the fibrous layer from off that structure, to form a cylindrical sheath which encloses both the aorta and pulmonary artery ; and secondly, by b 2 4 HEART. following the course which that membrane takes in forming partial investments for the two venae cavae and the four pulmonary veins. These two portions of the serous layer, viz., that lining the fibrous layer of the pericardium, and that lining the exterior of the heart itself, are perfectly continuous with each other, thus constituting a completely shut sac, so that the vessels going to, or issuing from the heart, do not perforate the serous membrane, but receive coverings more or less perfect from it. Nine openings have been enumerated in the fibrous layer of the pericardium, viz., one for the aorta, two for the right and left branches of the pulmonary artery, four for the four pulmonary veins, and two for the superior and inferior venae cavae. In the foetus there is another for the ductus arteriosus. Strictly speaking these are not openings in the fibrous layer of the pericardium, for this structure becomes incorporated with the external tunic of the vessels where they come in contact with it. When the pericardium has been opened, the following parts will be exposed : —the anterior superior surface of the heart, the two venae cavae, the aorta, the pulmonary artery, the right auricular appendix and a portion of the auricle, and the tip of the left auricular appendix. The left auricle is concealed chiefly by the aorta and pulmonary artery. GENERAL DESCRIPTION OF THE HEART. The Heart is a hollow muscular organ of a somewhat conical form, consisting of four chambers, grouped together so as to form an individual mass ; two of these are called the auricles, the other two the ventricles. The apex of the heart is formed (in the adult) by the extremity of the left ventricle ; and looks downwards, forwards, and to the left side, towards the interval between the fifth and sixth ribs : in many subjects it is curved a little back- Fig. 1.— Anterior View of the Heart. A, Arteria Innominata. B, Left Carotid Artery. C, Left Subclavian Artery. I), Aorta, fc, Kemains of Duct us Arteriosus. F, Pulmonary Artery. G, Superior or Descending Vena a™' '''B' 1 * Auricle. I, Posterior or Kight Coronary Artery. K, Left Aurieulir Appendix. L, Anterior or Left Coronary Artery. M, Left Coronary Vein. N Anterior surface of Right Ventricle. 6 HEART. wards. The base is turned upwards, backwards, and to the right side, and corresponds to the right side of the fifth, sixth, seventh, and, sometimes, partly to the eighth, dorsal vertebrae. The posterior inferior surface is flat and triangular, and the anterior superior surface convex and more extensive : these surfaces are separated by two margins : the anterior margin is thin, and looks downwards, forwards, and to the right side : the posterior margin, which is shorter but considerably thicker, looks in the opposite direction. The chief bulk of the heart is formed by the ventricles, particularly by the left ; and the auricles seem like appendages situated at its base. The two auricles are situated at the base of the ventricles, and towards its posterior part. When injected, and viewed as one, they form a crescentic mass, the concavity of which looks forwards and rather upwards, and embraces within it the aorta and pulmonary artery. The convexity looks backwards and somewhat downwards. The two extremities of the crescent are formed by the tips of the right and left auricular appendices. The two ventricles taken together form a conical mass, which gives the peculiar form to the heart; it is obliquely situated, the apex being directed downwards, forwards, and to the left side ; the base upwards, backwards, and to the right side. The anterior superior surface of this mass is convex, and presents a fissure which runs from the base to the right side of the apex ; this fissure lodges the anterior coronary artery and vein, and a quantity of fat, and divides the anterior siirface into a right and left portion : the latter is formed by the anterior surface of the left ventricle, and the former, which is much larger, is formed by the anterior surface of the right ventricle. In this latter situation, Dr. Baillie has described a white opaque spot, like a thickening of the serous layer covering the heart : it is sometimes not broader than a sixpence ; at other times 7 HEART. broader than a crown piece ; "it is so very common, that it can hardly be considered as a disease."* The posterior-inferior surface of the ventricular mass, which is less extensive than the superior, is nearly fiat, and rests on the superior surface of the diaphragm, with the interposition of the base of the pericardium. This surface also is divided into two portions of unequal size by a fissure running from the base to the right side of the apex, and containing within it the posterior coronary artery and vein, and some fatty tissue : the larger portion is formed by the left ventricle, the remaining portion by the right. The anterior margin of the ventricular mass is thin, longer than the posterior and formed by the right ventricle : the posterior margin is thick and convex, and is partly lodged, with the intervention of the pericardium, in a depression of the left lung, and is formed by the left ventricle. The apex is formed, in the adult, entirely by the left ventricle ; and the base presents for examination the following parts :—anteriorly, a funnel-shaped projection of the right ventricle which passes upwards, and is termed the infundibulum, and from which arises the pulmonary artery : on a posterior plane, concealed by the infundibulum, and more to the right side than the orifice of the pulmonary artery, is the origin of the aorta from the base of the left ventricle. Behind these two orifices the base of the ventricular mass presents a circular fissure, circumscribing that portion of it which corresponds to the auricles : this fissure is very deep posteriorly : lastly, the base of the ventricular mass is cut obliquely downwards and backwards at the expense of the posterior inferior surface, which is consequently shorter than the anterior superior surface. Having thus described the external surface of the heart, we may now proceed to consider individually its cham- * Baillie's Morbid Anatomy, by Wardrop, p. 54. Fig. 2— Posterior View of the Heart. A, Orifices of the Arteria Innominata, Left Carotid and l eft Subclavian Arteries. B, Superior Vena Cava. C, Orifice of the Aorta. D, Orifice of the Pulmonary Artery. E, E, E, Orifices of the Pulmonary Veins. F, Right Auricle G, Orifice of the Inferior Vena Cava. H, Eustachian Valve. I, Left Auricle. K, Posterior Coronary Vein. L, 1'osterior Coronary Arteiy. M, Left Auricular Appendix. N, Posterior part of Left Ventricle. 0, Posterior part of Kight Ventricle. HEART : RIGHT AURICLE. 9 bers, which are, as we have already observed, four in number ; two auricles and two ventricles. The Right Auricle is of an irregular shape ; it is said to possess the form of the segment of an ovoid : it presents for examination three walls, an antero-external, a posterior situated behind and between the orifices of the two venae cavae, and an internal or the septum auricularum : and two extremities, an anterior inferior, and a superior. The antero-external wall is easily defined, as it is formed by all that portion of the right auricle which may be seen on opening the pericardium ; it is convex, and presents several dark lines corresponding to the intervals between the musculi pectinati, to be described hereafter. In order to see the internal surface of the auricle, we should make two incisions ; one in a vertical direction through the front of the auricle, connecting the orifices of the superior and inferior venae cavae ; the other in a slightly curved direction, the convexity directed downwards, commencing at the lower part of the right auricular appendix, and terminating in the superior extremity of the preceding incision. In this manner a flap will be formed out of the external wall of the auricle ; and we will now have an opportunity of examining the structure of this wall. Its muscular fibres are arranged in fasciculi, somewhat resembling the teeth of a comb ; they have been therefore termed the musculi pectinati: in the intervals between these fasciculi, the lining membrane of the interior of the auricle, and the serous membrane covering the heart, are almost in immediate contact. A tubercle has been described as projecting from the back part of the posterior wall into the auricle, called the tuberculum Loweri. If we examine the entrance of the great veins into the auricle, we will observe that the superior cava passes downwards, forwards, and to the left side ; and the inferior cava, upwards, backwards, and to the left side : we can readily understand, therefore, that the portion of the auricle between their orifices must of necessity 10 RIGHT AURICLE. be salient towards the interior of this cavity ; this projecting part of the auricle placed between the openings of these two great veins, forms the tubercle of Lower. The use ascribed to it, is, to direct the blood towards the centre of the auricle, and thus prevent the currents of the superior and inferior venae cavae from directly opposing each other. The internal wall constitutes the septum between the two auricles ; it is obliquely situated, so that its right surface, which we are at present examining, looks also a little forwards. On its lower portion it presents a wellmarked depression somewhat oval in form, called the fossa ovalis : it is bounded by two well-defined ridges or pillars, one on either side ; that on the right side being also placed posteriorly ; that on the left, anteriorly : the latter is much stronger than that on the right side, and it separates the fossa ovalis from the opening of the coronary vein, and gives attachment to the left cornu of the great Eustachian valve. These two pillars are continuous with one another superiorly, so as to form an arch over the fossa ovalis, the concavity of which is directed downwards. This prominent margin which bounds the fossa, has received the name of the annulus Vieussenii. It is not, however, correctly speaking, an annular projection, the pillars not being joined together inferiorly. That portion of the septum included between the pillars, and which may be called the floor of the fossa ovalis, contributes to form a valvular opening between the auricles in the intra-uterine period of life. This opening has been called the foramen ovale, or foramen of Botal, although it had been previously described by Galen. The upper part of the floor projects into the left auricle above the point of junction of the pillars of the fossa, and there forms an arch, the concavity of which is directed upwards ; this can be seen only from the interior of the left auricle. Before the second month of intra-uterine life, this valvular apparatus does not exist; there is in fact at this period 11 RIGHT AURICLE. a direct communication between the auricles : at the end of the second month, it begins to be developed ; and at the seventh month, the superior margin of what we have called the floor of the fossa ovalis, ascends sufficiently high into the left auricle, to cut off the direct aperture of communication ; leaving however an oblique or valvular channel between the auricles. This aperture of communication is, in the normal state, closed in the adult by the adherence of the upper edge of the valve, to that surface of the annulus of Vieussens which looks towards the left auricle. Related to the opening of the inferior vena cava and to the fossa ovalis, we observe the great Eustachian valve ; it presents a crescentic form : the concave margin, which is generally well-defined, is free, and looks upwards and towards the right shoulder ; the convex margin is not at all so well-defined, being in fact continuous with the lining membrane of the anterior wall of the inferior cava, at that spot where this vein and the auricle become united with each other : this margin of the valve looks downwards and towards the left side. The valve has two cornua or extremities, one, the superior or left cornu is attached to the anterior pillar of the fossa ovalis ; the other, inferior or right, is at first united to the anterior wall of the orifice of the inferior cava, and then sends an expansion in front of this orifice round towards its right side, where it becomes lost in the structure of this portion of the vein, usually without reaching the right pillar of the fossa ovalis. The superior or left attachment of the valve contributes to separate the fossa ovalis from the orifice of the coronary vein, whilst lower down we find this valve separating the opening of this vein from that of the inferior vena cava. In the early periods of foetal development, the valve is proportionally well marked ; but it gradually diminishes as the valve of the foramen ovale or fossa ovalis increases towards its perfect development. The Lesser Eustachian Valve, or Valvula Thebesii, or valve of the coronary vein, is a 12 RIGHT AURICLE. small duplicature of the lining membrane of the vein and auricle : it arises below the anterior attachment of the greater Eustachian valve, and, separating from it as it descends, turns underneath the orifice of the coronary vein, and becomes attached to the margin of the right auriculo-ventricular opening. The anterior inferior extremity of the auricle looks towards the right ventricle, i. e. downwards and forwards : in it we observe the right auriculo-ventricular opening, the long axis of which is directed from before backwards. The superior extremity of the right auricle presents to our notice the right auricular appendix, and the opening of the superior vena cava, with a smooth surface situated between these two parts : the right auricular appendix is triangular in its form, and situated between the aorta and right ventricle : its base is continuous with the auricle, without any line of demarcation : its apex is turned transversely towards the left side : posteriorly it is concave, and overlaps the aorta : its interior is strongly marked by musculi pectinati. The superior cava takes a direction downwards, forwards, and to the left side : its orifice is situated on a plane anterior to that of the inferior cava : two prominent muscular bands bound this opening : one of them separates it from the orifice of the inferior cava ; the other, not so well marked, is situated on the left side, and separates the orifice of the vein from the auricular appendix. The inferior cava, in approaching the heart, takes a direction upwards, backwards, and to the left side : at first it ascends almost perpendicularly, and then assuming a more horizontal direction, turns abruptly into the auricle, immediately before which it frequently presents a dilatation. Its orifice is larger than that of the superior cava, and is situated on a plane posterior to it : it likewise differs from it in its relation to the Eustachian valve. A number of minute openings on the inner surface of the auricle have been described as the orifices of what are Fig. 3.—Interior of Right Auricle and Ventricle. A, Superior Vena Cava. B, Aorta. C. Musculi recflnati of tho Right Auricular Appendix. D, Pulmonary Artery. E, Interior of the Kight Auricle. F, Opening of the Superior Vena Cava. G, Annnlus of Vienueri, H.Kossa Ovalis I, Eustachian Viilve. K, Inferior Venn Cava, L, Opening of the Coronary Vein. M, Valve of '1 hebesius N, Cvlty of Kight Ventricle. O, Section of the Kight Ventricle at the septum. F, Cunicce Columnar 14 LEFT AURICLE. termed vence Thehesiance : it is by no means certain that they are the orifices of vessels. The Left Auricle when distended presents somewhat the form of a four-sided pyramid, the base of which is situated at its right side and forms the septum auricularum ; while the truncated apex constitutes the left wall or side of this cavity. At the anterior and upper portion of this latter wall, where it joins the superior, we find the opening of the left auricular appendix ; and farther back, where the left wall unites with the posterior, we find the openings of the left pulmonary veins. The posterior wall is directed a little upwards ; and at its right extremity, and upper angle, immediately behind the septum auricularum, we find the openings of the right pulmonary veins. The anterior wall looks somewhat downwards ; it corresponds to the left ventricle, and presents to our view the left auriculo-ventricular opening. The superior wall looks a little forward. Lastly, the inferior wall is very smooth, and forms with the posterior wall a continuous convex surface which corresponds, with the interposition of the pericardium, to the oesophagus and descending aorta. The left pulmonary artery may be seen crossing from before backwards, so as to get behind the left auricular appendix. In order to see the interior of the left auricle, an incision should be made vertically through its posterior and superior walls, so as to separate the pulmonary veins of the right and left sides. We may now observe that the septum of the auricles is convex towards the left side ; in the foetus it presents the valve already described in connexion with the fossa ovalis, but in the adult it is by no means so distinctly marked. The auriculo-ventricular opening situated in its anterior wall, is smaller than that on the right side, and its long axis is directed somewhat transversely. The superior portion of the left wall presents the orifice of the auricular appendix, which is RIGHT VENTRICLE. 15 smoother internally than that on the right side : and lastly, opening into the posterior wall, we observe superiorly, the four pulmonary veins, the orifices of which are unprovided with valves : sometimes the two veins of the left side have a common opening ; but when there are four, the two inferior veins have the larger openings, and the two left veins are nearer to each other than the two right. From the above account it appears that there are seven openings into the left auricle of the foetus, viz. the four openings of the pulmonary veins, the opening of the left auricular appendix, the left auriculo-ventricular opening, and the foramen ovale. There are commonly but six in the adult, the foramen ovale being ordinarily closed : a small valvular opening, however, occasionally exists in the adult at the upper part of the fossa ovalis. The interior of this auricle, with the exception of its appendix, is destitute of musculi pectinati; it is therefore smoother than the interior of the right auricle ; it is also stronger in its muscular structure, and its capacity is about one-fifth less. The Right Ventricle has the form of a cone, one side of which has been hollowed out to accommodate the convexity of the left ventricle. Its apex is turned in the same direction as the apex of the heart ; but, in the adult, does not extend so low. Its base presents, anteriorly and to the left side a funnel-shaped pouch, called the infundibulum, or conus arteriosus, from which the pulmonary artery arises ; and, posteriorly, the opening into the right auricle : between these two openings it corresponds to the origin of the aorta. In order to expose its interior an incision should be made into it, in the direction of the axis of the heart, and close to the septum ventriculorum. The internal surface of the right ventricle is exceedingly rough from the development of a number of muscular prominences, termed the carnem columnce : of these there are three orders : those of the first order are attached by both extremities, and by one side to the ven- 16 RIGHT VENTRICLE. tricle ; those of the second, are attached by their two extremities ; and those of the third order are attached by only one extremity to the ventricle, the other being connected, through the medium of tendinous chords (chordce tendinece), to the valves of the auriculo-ventricular opening. The two first are supposed to be for the purpose of mixing the blood more completely ; but those of the third order, contracting at the same time with the ventricle, prevent the blood from forcing back the valves into the auricle. That portion of the interior of the ventricle which forms the infundibulum, is exceedingly smooth, in order to facilitate the flow of blood into the pulmonary artery ; and it will be observed, that several of the columns of the first and second orders have one of their extremities attached to the commencement of that portion of the septum, which contributes to form the infundibulum. By means of this beautiful arrangement, these columns during the contraction of the ventricle, draw upon this portion of the infundibulum, and so, by maintaining its tension, preserve its smoothness of surface for the passage of the blood into the pulmonary artery. The right auriculo-ventricular opening is seen at the base of the ventricle, posteriorly, and about an inch to the right of the orifice of the pulmonary artery : it is circular when the blood is passing through, but elliptical at other times. Surrounding this opening are seen three triangular folds of the lining membrane or endocardium, which constitute the tricuspid valve. This valve consists, as its name implies, of three portions, each triangular ; the base attached to the zona tendinosa, surrounding the right auriculo-ventricular aperture, the apex connected with the chordae tendinese : the anterior portion corresponds to the anterior wall of the right ventricle ; the posterior corresponds to the septum ventriculorum ; and the left division looks towards the opening of the pulmonary artery : this last is the largest portion of the valve, and is called the valvular septum of Lieutand of the right 17 RIGHT ventricle. ventricle : it is supposed to be of use in preventing any of the blood flowing from the right auricle, from getting directly into the pulmonary artery, until it has first filled the right ventricle : by this arrangement the blood becomes subject to the entire force of the right ventricle, in order to its propulsion through the pulmonary vessels. The auricular surface of the tricuspid valve is extremely smooth, for the purpose of facilitating the flow of blood into the ventricle ; whilst the surface which corresponds to the walls of the ventricle, is remarkably rough, from the prominences formed by the chordae tendinese. To the margins of the valve the chordae tendineae are attached and afterwards become spread out, interlacing with each other, so as to give rise to a strong fibrous expansion between the foldings of the lining membrane which form each division of the valve : they are ultimately lost by becoming continuous with the zona tendinosa surrounding the base of the ventricle. The tricuspid valve prevents the blood from returning into the auricle, when the ventricle contracts to expel it into the pulmonary artery : this, however, it does not do completely, as a certain amount of regurgitation is permitted into the right auricle at this particular moment, in the healthy condition of the parts. In 1792, John Hunter writes, " I have reason to believe that the valves in the right side of the heart, do not so perfectly do their duty, as those of the left ; therefore, we may suppose it was not so necessary."'" Many years back, Mr. Adams saw the force of Hunter's observation, and fully appreciated its importance. In his original and admirable paper on Diseases of the Heart, published in 1827, when speaking of the fact alluded to by Hunter, he observes, "this circumstance, in my opinion, has not been sufficiently noticed, nor the influence that such a structure may have on the circula- * "Treatise on the Blood," &c. page 177. 0 18 RIGHT VENTRICLE. tion in its natural, or morbid state, considered.—Such a provision was absolutely necessary in the right or pulmonary ventricle, as various natural causes must momentarily retard the passage of blood through the lungs.—In the natural state of the heart, it is probable that there is constantly some little reflux into the right auricle, during the contraction of its corresponding ventricle, as the valves readily admit it; but the great swelling of the jugular veins is only seen when extraordinary efforts are made, or when, from any enlargement of the right side of the heart, it is capable of containing a larger quantity of blood than it can readily transmit through the lungs, or the left receive ; on these occasions it is, that the pulsations in the jugular veins become evident ; they are synchronous with the action of the heart. Upon the whole, therefore, I would conclude, that the pulsation in the jugular veins, viewed as a symptom of the disease we have been just considering (contraction of the left auriculo-ventricular opening), depends upon this, that the right ventricle, unable to transmit all the blood which distends it, through the pulmonary artery, part of it must regurgitate towards the auricle, and displace a column of blood descending into this cavity from the jugular veins, causing thus a momentary reflux or pulse in the veins nearest the right auricle."* In the second volume of the Guy's Hospital Reports, 1837, Mr. King published '' An Essay on the Safety-valve Function of the Human Heart," , The Pulmonary Artery. E, Remains of the Ductus Arteriosus. F, Right Auricle. tricuspid Valve. H, Portion of Itight Aurloulo-Veutrioular Opening. I, Fleshy l.olumn connected with the Septum of tho Ventricles bv one extremity, and with the Val • vtaarBeptuni of Lieutaud by the other. K. Part of Left Auricle. M, Cornea! Columnar: attached to the Chorda Tendlneffi. N, Cavity of Right Ventricle. O, Septum Ventrioulorura. 20 LEFT VENTRICLE. cavity. Of the three divisions of the tricuspid valve, he describes two, viz. what he calls the anterior curtain and the right curtain, as being attached to the fleshy columns which are fixed in the yielding wall. From this mechanism he concludes, that when from 3udden repletion, exertion, exposure to cold, or impeded respiration, a distention occurs in the great veins and right side of the heart, the yielding wall will carry the valves partly away from one another, and by such separation will prevent the injurious effects of over-distention, by producing the necessary amount of regurgitation from the right ventricle into the right auricle and great veins. To this valvular apparatus, which guards the right auriculoventricular opening, Mr. King gives the name of the "safety-valve." By the "tendinous zone" is meant the whitish ring that bounds the auriculo-ventricular opening : as there is a similar one on the left side, we shall consider both at the same time. The Left Ventricle. This cavity also is of a conical form : its apex constitutes, in the adult, the apex of the heart : and its base has an arterial, and an auricular opening. The interior of the left ventricle may be exposed by an incision similar to that recommended when speaking of the right: the arterial opening thus exposed, will be found in front of the auriculo-ventricular aperture, and a little to its right side. The auriculo-ventricular opening is guarded by two triangular folds of the lining membrane, which constitute the mitral valve of Vesalius. The anterior lamina of this valve is much larger than the posterior, and has been correctly termed the valvular septum of Lieutaud of the left ventricle ; that anatomist supposed that it was applied against the orifice of the aorta, while the ventricle was filling : this appears possible, as the aortic opening is in front of the auricido-ventricular, and the substance of this valve separates the two openings 21 TENDINOSiE. from each other. The mitral valve is similar in structure to the tricuspid : it does not, however, admit of regurgitation of the blood from the left ventricle into the left auricle ; and the two surfaces of the anterior division of the valve are equally smooth ; —the posterior surface for the purpose of facilitating the flow of blood from the auricle into the ventricle ; and the anterior, the flow from the ventricle into the aorta. In this respect this portion of the valve differs from the posterior, and from the three portions of the tricuspid valve. The muscular structure of this ventricle is much thicker and stronger than that of the right ventricle. The zonae tendinosm of the heart are four in number ; one is situated at the narrow portion of the infundibulum of the right ventricle and gives attachment to the origin of the pulmonary artery : the second is placed at that part of the left ventricle from which the aorta takes its origin ; these may be called the two arterial zones. The remaining two may be termed the auriculo-ventricxdar zones ; they mark the connexion between the auricles and ventricles, surround the auriculo-ventricular orifices, and give attachment to the bases of the tricuspid and mitral valves : they are composed of pale, condensed, tendinous fibres ; they have the same form as the auriculo-ventricular openings, which they surround ; and they receive and are continuous with those expansions of the chordae tendineae, which are placed between the laminae of the endocardium composing the mitral and tricuspid valves, and which thus add considerably to their strength. These zones may be best seen by dissecting from the interior of the heart. The endocardium, or lining membrane is in intimate connexion with the inner surface of these zones, and is thicker here than in other situations. According to Bouillaud, the cavity of each ventricle is composed of two very distinct regions, one communicating with the corresponding auricle, and the other with the artery arising from its base ; and these two portions 22 botjillaud's opinions. are not constituted exactly alike in the right and left sides. In the right ventricle, the arterial portion is united with the auricular portion, by means of an angle projecting into the ventricle, the sinus of which is consequently turned upwards, embracing the aorta. In the left ventricle the arterial and auricular regions are very nearly parallel to each other, so that their axes approach one another as they proceed from the base to the apex of this cavity : they are separated by the anterior lamina of the mitral valve, and by two large fleshy columns, which are inserted into it by means of numerous tendons. Inferior, posterior, and a little to the left of this septum is the auricular region of the ventricle ; and superior, anterior, and internal to it, is the arterial or aortic portion. These two regions communicate with each other freely at the interval between the two large columns above mentioned. It is in the auricular region of the ventricle that we principally find the fleshy columns ; in fact, a large portion of the arterial region is altogether destitute of them ; and the same remark will apply to the right ventricle : those that are found in the arterial region are small and interlaced, and are not, like the large ones, inserted into the valves. The left ventricle contains fewer carnese columnse than the right ; they are, however, more voluminous. Relative capacities of the Cavities. Each of the four cavities of the heart is capable of containing about two ounces of blood. The ventricles are supposed to contain a little more than the auricles. The right auricle and right ventricle are somewhat larger in their capacities than the cavities of the left side ; anatomists are not, however, fully agreed upon this point. The weight of the heart is estimated at about from eight to ten ounces. Fig. a.—This figure represents the Interior of Left Ventricle and Aorta laid open by dissecting from before backwards. A, Aorta. B, C, Left Pulmonary Veins. D, D, Orifices of the Coronary Arteries. E, Ulterior of Left Auricle. F, F, Semilunar Valves of t'.c Aorta. O, Anterior Surface of the valvular Septum of Lieutaud, and passage from the Cavity of the Ventricle into the Aorta. a. Attachment of Chorda? Tendmea) to the Mitral Valve. I, Left Auriculo-Ventricular upemng. J, Carnea; Columnas. K, Lower Portion of the Cavity. L, Right Auricular Appendix. M, Caraese Column®. N, Bight Ventricle. O, Septum Ventricnlorum dissected, ana cut suriace shown. 24 MUSCULAR FIBRES OF THE HEART. STRUCTURE OF THE HEART. The heart is essentially composed of muscular fibres, covered on the outside by the serous layer of the pericardium, and on the inside by the endocardium, which is continuous with the lining membrane of the arteries and veins. It has been ascertained by Muller, that the primitive fasciculi of the muscular structure of the heart, present the transverse striae or cross markings which are seen upon the primitive fibres of the voluntary muscles. Todd and Bowman state, that ' 4 The cross stripes on the fibres of the heart are not usually so regular or distinct, as in those of the voluntary muscles. They are often interrupted, or even not visible at all. The fibres are usually smaller than the average diameter of those of the voluntary muscles of the same subject by two-thirds, as stated by Mr. Skey ; and in most parts of the parietes of this viscus, they are not aggregate in parallel sets, but twine and change their relative positions."* Entering into the composition of the heart, we find also tendons, arteries, veins, nerves, and absorbents : it is said to possess fittle or no areolar tissue. The muscular fibres of the heart may be traced, first in the ventricles, and afterwards in the auricles. In order to prepare the heart for the examination of these fibres, it should be hardened by maceration in alcohol, or by boiling : its external and internal membranes may be then cautiously raised, and the different layers of muscular fibres examined, commencing with those most internal, and following carefully the course of the fibres. First; —in each of the ventricles we find a proper set of fibres arranged so as to form a small conical sac, open at both extremities, the inferior opening being much the * Physiological Anatomy, vol. 1, p. 161. 25 MUSCULAR FIBRES OF THE HEART. smaller : these may be termed ventricular sacs. In addition to the proper fibres, the ventricles have also a common set, which cover and unite the proper ones, and inferiorly at the apex of the heart become inflected and penetrate the small apertures above mentioned, in the ventricular sacs, on the internal surface of which they are expanded. They have been represented as forming six sets of layers in the left ventricle, and three in the right; the fibres do not confine themselves to particular planes : but the planes mutually penetrate each other, and are moreover united by fibres reciprocally detached from one to the other. The superficial fibres proceed spirally from the base to the apex ; those on the anterior surface incline from right to left, and those on the posterior surface from left to right. Having arrived at the apex of the heart, they are inflected as already observed, towards its interior, and therefore present in this situation, when the pericardium has been carefully dissected off, the appearance of a star, the rays of which are not straight, but curved. The inflected superficial fibres enter the openings in the ventricular sacs, and therefore both ventricles may be penetrated at the apex of the heart, without dividing the fibres. In the interior of the ventricles, some of the inflected fibres ascend from the apex on the interior of the same wall upon which they had descended in passing downwards from the base : others ascend on the opposite wall; and a third set terminate in the carnese columnse. Secondly ; —in each of the auricles the proper fibres arise from the tendinous zones : on the left side some of them assume a circular arrangement in the vicinity of the auriculo-ventricular openings, and numerous oblique bands proceed from the same origin in various directions : one passes between the appendix and left pulmonary veins ; another fills the interval between the pulmonary veins of the right and left sides, and others between the pulmonary veins of the same side, forming a border for their orifices ; independently of 26 MUSCULAR FIBRES OF THE HEART. which the orifices seem specially provided with proper sphincters. On the right side, the part of the auricle corresponding to the junction of the superior and inferior cavse, has no muscular fibres except a small band on the right side of the orifice of the superior cava. In the rest of the auricle we distinguish two principal muscular bands ; one embracing, in a circular manner, the right auriculo-ventricular opening; and the other descending from the interval between the right auricular appendix and superior cava, to terminate on the right side of the inferior cava. Between these two bands the muscular fibres are arranged in a fasciculated manner, constituting the musculi pectinati. The superficial fibres of the auricles constitute a thin layer passing transversely from one auricle to another, and arising from, and terminating in the tendinous zones. From the above account, it follows that the right and left sides of the heart may be separated from each other by the division of the common fibres, leaving the proper fibres uninjured. For this purpose an incision should be made with caution through the anterior fibres of the ventricles, parallel to the anterior fissure of the heart, and then the right and left sacs, above described, constituted by the proper fibres, may be separated with the finger. In order to separate the auricles, the incision should be made parallel to their posterior median fissure, and still greater caution is necessary here than in the separation of the ventricles. The ventricular sacs have been described as having a conical form : this is strictly true, more particularly of the left side, all parts of the exterior of the left sac being convex ; but on the right side, the part of the sac which is applied to the left ventricle is concave. Now the reverse occurs in the auricles, the right presenting a convexity which is received into the concavity of the left. Mr. Searle remarks, that "the fibres of the heart are not connected together by cellular tissue, as are those of 27 MUSCULAR FIBRES OF THE HEART. other muscles, but by an interlacement which in some parts is very intricate, and in others scarcely perceptible. At the entire boundary of the right ventricle they decussate, and become greatly intermixed; at the apex and base of the left ventricle they twist sharply round each other, and so become strongly embraced, but in general the interlacement is so slight that they appear to run in parallel lines. Whether a mere fasciculus, or a considerable mass of this last description of fibres, be split in the direction of the fibres, a number of delicate parallel fibres will present themselves, some being stretched across the bottom of the fissures, perfectly clean and free from any connecting medium whatever ; and although some must necessarily be broken, yet these are so few that they do not attract attention unless sought for. The disposition of the fibres varies in different parts of the heart, forming parallel lines, angles, decussations, flat and spiral twists. The fibres are arranged in fasciculi, bands, layers, and a rope, which are so entwined together as to form the two chambers called the right and left ventricles. These are lined with their internal proper membrane. The fasciculi contribute to the formation of the bands. By tracing the fibres in bands, we are enabled to develope the formation of the ventricles in a progressive and systematic manner. The bands spring from a mass of fibres which forms the apicial part (the apex) of the left ventricle, and which in winding round, just above the apex of the heart, separates into two bands to form the right ventricle. The average width of the bands is not less than a third of the extent between the apex and base of the left ventricle. A considerable mass of fibres may be exposed winding just above the apex ; at the septum it splits into two bands; the one a "short band," encircles spirally both ventricles, one half round the right, the other half round the left ventricle. The second, or "longer bamd," describes two circles; it first passes through the septum, and round the left ventricle ; it secondly 28 MUSCTOAR FIBRES OF THE HEART. passes round the base, and includes both ventricles in its circuit. The fibres of this band, in forming the brim of the left ventricle, make a sharp twist like those of a " rope" by which means they become the inner fibres of this chamber, and expand into a layer which enters largely into the formation of that mass which has already been described as forming the apex of the left ventricle, and dividing into the two bands. Thus the principal band, although it receives several increments of fibres, has no complete beginning nor ending, a considerable portion of it originating and terminating in itself. "The septum of the ventricles is composed of three layers ; a left, a middle, and a right layer. The two former properly belong to the left ventricle ; and the last, or right layer, exclusively pertains to the right ventricle. The two former are composed of the primitive mass of fibres derived from the '' rope" already alluded to as forming the brim of the left ventricle, and the carneas columnse of the same ventricle. The last, or right layer of the septum, has not the same origin as the two former have ; its fibres arise from the root and lower margin of the valve of that section of the aorta which pertains to the right ventricle, from that part of the root of the pulmonary artery contiguous to the aorta, and from the carnese colunmee of the right surface of the septum." ' 1 It appears from the patient and laborious investigations of Mr. Searle, that the great mass of the fibres of the heart are arranged in a spiral direction ; that many of them take a single curve, so as to surround both ventricles ; that others dip into the septum and form a double curve, one surrounding the right ventricle, the other the left; whilst several others penetrate from the exterior into the apex, and become continuous with the carnese columnse in the interior of the ventricles."* * Todd's Cyclopaedia, p. 619. 29 THE ENDOCARDIUM : ARTERIES OF THE HEART. The spiral course taken by the fibres of the ventricles, and the continuity of the external with the internal fibres of these cavities, were known long ago to Winslow, Lancisi, Lower and Gerdy. THE ENDOCARDIUM. This is a transparent membrane, much more delicate than the serous membranes, which, however, it strongly resembles. Its free surface is highly polished and glistening ; its attached surface is united to the subjacent tendinous and muscular structures by very fine areolar tissue, which is often found thickened and altered by disease, particulary at the left side. The endocardium is thicker in the left cavities of the heart than in the right, and thickest opposite the auriculo-ventricular and arterial orifices, in which situations it is often found morbidly thick and rough, in consequence of chronic inflammation. It consists of a layer of epithelium placed on a stratum of fine fibres, which exhibit minute wavings. The epithelium appears to be extremely delicate, but the same in all its characters as that of the blood vessels. It is so delicate, that to be seen satisfactorily it must be examined in animals just killed. We observe two forms of epithelial particles, one soft, rounded, and globular ; the other somewhat compressed and drawn out at opposite poles into pointed or fibre-like processes. It is difficult to determine the precise relative position of these two forms of epithelium ; but it seems probable that the pointed processes are the more deeply seated, and are in immediate contact with the subjacent fibrous layer, which here corresponds to the basement membrane beneath the epithelium of serous and mucous membranes. * The Arteries of the heart are two in number, viz. the posterior and anterior coronary. * Todd and Bowman's Physiological Anatomy, vol. ii. p. 335. 30 ARTERIES OF THE HEART. The posterior, or right coronary artery, arises from the aorta, above the margin of one of the semilunar valves ; and after communicating with the left coronary behind the pulmonary artery, proceeds outwards in the groove between the right auricle and right ventricle. Having reached the inferior surface of the heart, it divides into two branches ; one of which continues in the same groove, and winding round the base of the heart, anastomoses with the left coronary artery ; it supplies the right auricle and ventricle : the second, from its size appears the continued trunk : it descends in the groove on the posteriorinferior surface of the heart, accompanied by the posterior coronary vein, along the septum ventriculorum, supplies both ventricles, and near the apex of the heart anastomoses with the left coronary. The branches of the right coronary, before its division, are the following : first, auricular branches, five or six in number, which supply the right auricle, the septum auricularum, and the parietes of the venae cavae ; secondly, ventricular branches, much larger, which are distributed to the right ventricle ; some of these descend on the superior surface of the heart, others on the inferior, and one along its right or thin margin. The anterior, or left coronary artery, smaller than the right, arises from the aorta, above the margin of one of the semilunar valves ; it then proceeds to the left, till it escapes from beneath the pulmonary artery and divides into a superior and inferior branch. The superior winds round the base of the heart in the groove between the left auricle and left ventricle, concealed by the coronary vein, and anastomoses with the right coronary artery : in this course its branches are distributed principally to the left ventricle ; others go to the left auricle and the pulmonary veins. The inferior branch is the larger ; it descends on the anterior-superior surface of the heart, accompanied by the anterior coronary vein, in the groove between 31 VEINS OF THE HEART. the two ventricles. Its first branches ramify on the commencement of the aorta and pulmonary artery ; the rest are distributed to the ventricles, principally to the left. The Veins of the heart are the greater and lesser coronary : the greater coronary vein commences at the apex of the heart, and ascends, under the name of the anterior coronary vein, through the anterior fissure, gradually increasing in size : having arrived at the base of the ventricles, it quits the coronary artery, and turns off at a right angle to the left side. In this manner it gets into the groove which separates the left auricle from the left ventricle, and having thus arrived at the inferior surface of the heart, it opens into the posterior inferior part of the right auricle, as already described. Immediately before its termination, this vein presents a remarkable ampulla or dilatation. In the ascending part of its course it receives branches from the septum ventriculorum, and from the right and left ventricles ; and during its transverse direction it receives descending branches from the auricle, and ascending and larger branches from the ventricle, one of which runs along the left margin of the heart. In its ampulla we usually find terminating, the posterior coronary vein that ascends through the posterior inter-ventricular fissure, and another that crosses from right to left between the right auricle and right ventricle. This vein has no valves, except the lesser Eustachian valve, already described as situated at its opening into the right auricle. The lesser coronary veins open separately into the inferior part of the right auricle : among them we need only notice a small one that descends from the infundibulum of the right ventricle, and another the vena Oaleni, which ascends along the anterior margin of the heart. The coronary vein has been seen to enter into the 32 NERVES OF THE HEART. left auricle ;* and Lecat relates a case in which it opened into the left subclavian vein.f The Nerves of the heart are principally derived from the cervical ganglia of the sympathetic nerve ; the remainder proceed from the pneumogastric and recurrent nerves : they are distributed in greater number on the right side than on the left. The Cardiac nerves, derived from these sources, converge from both sides upon the origin of the aorta and pulmonary artery, and form the cardiac plexuses, which, dividing into the right and left coronary plexuses, surround and accompany the coronary arteries and their branches. There are three principal cardiac nerves derived from the sympathetic on each side, viz., the superior or superficial cardiac, the middle or deep cardiac, and the inferior or small cardiac nerves. The Superior cardiac nerve arises from the superior cervical ganglion of the sympathetic, or from the communicating branch which connects this ganglion with the middle ; it is joined by one or two filaments from the pneumogastric nerve. The Middle cardiac nerve arises from the middle cervical ganglion ; but when this ganglion is absent, the nerve arises from the trunk of the sympathetic itself. Scarpa has called this the great cardiac nerve, from its frequently being the largest of the three : sometimes, however, it is absent altogether. The Inferior cardiac nerve, called also the cardiacus minor, usually arises from the inferior cervical ganglion, very often from the first thoracic ganglion. The middle and inferior cardiac nerves communicate freely with branches from the recurrent. * Jeffray on the Foetal Heart. f Mem. de l'Acad, des Sciences, 1738. 33 NERVES OF THE HEART. There are some differences between the cardiac branches of the right and left sides, viz., the middle cardiac nerve of the left side receives its principal branch from the inferior cervical ganglion ; and very frequently on this side the middle and inferior cardiac nerves are united into a single trunk. The cardiac branches of the pneumogastric nerve of the right side are usually three or four in number, and arise from their parent trunk about an inch above the origin of the common carotid artery; they are lost in the cardiac filaments of the inferior cervical ganglion. The pneumogastric nerve of the left side generally sends off only a single twig, which runs on the front of the arch of the aorta and enters the neighbouring cardiac plexus. The cardiac plexuses are three in number, —the great, the superficial or anterior, and the deep or posterior. The first is seen in front of the trachea and above the right pulmonary artery, and behind the arch of the aorta ; it is formed principally by the middle and inferior cardiac nerves of both sides. The second is situated upon the front of the aorta, close to its origin, and may be exposed by removing the serous layer of the pericardium from this vessel : branches from the great cardiac plexus, from the superior cardiac nerves, and from the cardiac ganglion, enter this plexus. The third is situated immediately behind the origin of the aorta. The cardiac ganglion of Wrisberg when present, is situated underneath the arch of the aorta, and is in contact with that part of the concavity of the artery which lies to the right side of its connexion with the ductus arteriosus : the superior cardiac nerves of the right and left sides, together with filaments from the pneumogastric nerves, enter into its formation. The cardiac branches of the recurrent nerve are pretty numerous, and unite with the cardiac branches of the pneumogastric and great sympathetic. The anterior and posterior coronary plexuses are branches i) 34 PULMONARY ARTERY. derived from the cardiac plexuses, which accompany the coronary arteries and their branches. The Lymphatics of the heart consist of a superficial and a deep set : the superficial set form a net-work under the serous layer of the pericardium : the deep set ramify between the endocardium and muscular fibres ; and both of them follow the coronary vessels. Some of them unite with the lymphatics of the lung, and others terminate in the lymphatic glands in front of the arch of the aorta and pulmonary veins. THE PULMONARY ARTERY. This vessel may be easily injected from the superior or inferior vena cava. It arises from the infundibulum of the right ventricle : its direction is upwards, backwards, and to the left side ; and after a course of about an inch and a quarter, it terminates by divicling into a right and left branch. In the angle between these branches, but more connected with the left than with the right, the ductus arteriosus arises : this vessel in the foetus equals in size, and seems like a continuation of the pulmonary artery ; it terminates in the concave side of the arch of the aorta, a little beyond the origin of the left subclavian artery. Superiorly, and to the right side of the bifurcation of the pulmonary artery, we see the bifurcation of the trachea into the right and left bronchial tubes. Between the division of the artery below, and that of the trachea above, we find a space somewhat of a lozenge shape, which is filled with a considerable quantity of areolar tissue, a number of black bronchial glands, together with numerous branches of the pulmonary plexuses of nerves, chiefly those derived from the posterior. The pulmonary artery, after its origin, forms a curvature, the convexity of which looks forwards and to the left side, and is covered by the serous layer of the pericardium, with the interposition of some adipose tissue : its concavity looks backwards and to the right 35 PULMONARY ARTERY. side, and corresponds to the commencement of the aorta : on either side it is related to the appendix of the corresponding auricle. The pulmonary artery, unlike the aorta, does not in the undisturbed state retain its cylindrical form ; this is owing to the comparative thinness of its proper or middle elastic coat. We have already mentioned that this vessel and the commencement of the aorta, have a common sheath formed by the reflexion of the serous layer of the pericardium : within this sheath, and behind and between the vessels, filaments of the sympathetic nerve descend to form the coronary plexuses. If we now cut into the artery, and examine its interior, we observe that there are three semilunar valves at its orifice, and that an incision through its anterior part will divide one of them ; whereas an incision into the anterior part of the aorta would nearly separate two of them, viz., the right from the left. The middle or proper coat of the pulmonary artery will be found to take its origin from the arterial zona tendinosa situated at the termination of the infundibulum of the right ventricle, by a festooned margin presenting three convexities or inverted arches, separated from each other by a small triangular interval, in which we find no proper arterial tunic. The connexion between the three inverted arches and the zona tendinosa will be best seen by dissecting the parts from the interior of the ventricle. The muscular fibres of this portion of the ventricle will be seen attached to the lower margin of the tendinous zone, whilst the three inverted arches of the middle coat of the artery will be found connected with its upper margin by condensed areolar tissue. Corresponding to each of the three small triangular intervals between the inverted arches of the middle coat, we will find a fibrous prolongation sent up from the upper margin of the zona tendinosa ; this becomes ultimately incorporated with the condensed areolar tunic external to the middle coat. The endocardium within, and the serous layer of the pericardium without, though 36 OBSERVATIONS OF DR. HOPE. but partially, complete the connexion between the artery and the ventricle. Between each of these convexities and the area of the vessel, we find a corresponding semilunar valve formed by the lining membrane of the artery the concavity of which looks upwards and is strengthened by a small body called the corpus sesamoideum or corpus Arantii. The right pulmonary artery crosses transversely behind the aorta and superior cava, to which consequently its anterior surface corresponds with the interposition of the serous sheath of the aorta. Posteriorly and superiorly it corresponds to the right bronchus, and inferiorly to the right auricle. The left pulmonary artery, shorter than the right, and less horizontal, ascends in front of the left bronchus, being covered anteriorly by the serous layer of the pericardium, except in the immediate vicinity of the lung, where it is covered by its corresponding veins. Above and behind it, is the arch of the aorta ; beneath it, is the superior wall of the left auricle, and in front of it is the left auricular appendix. It may not be considered out of place to quote the following observations of Dr. Hope, as to the relative positions of the heart and its great vessels with regard to the parietes of the chest.—"A line drawn from the inferior margin of the third ribs, across the sternum, passes over the pulmonic valves a little to the left of the mesial line, and those of the aorta are behind them, but about half an inch lower down. From this point the aorta and pulmonary artery ascend ; the former inclining slightly to the right, coming in contact with the sternum, when it emerges from beneath the pulmonary artery, and following, or perhaps rather exceeding, the mesial line till it forms its arch ; the pulmonary artery, which is, from the first, in contact with the sternum, inclining 37 OBSERVATIONS OF DR. HOPE. more considerably to the left, until it arrives at the interspace between the second and third ribs above described. A vertical line coinciding with the left margin of the sternum, has about one third of the heart, consisting of the upper portion of the right ventricle, on its right ; and two thirds, composed of the lower portion of the right ventricle, and the whole of the left, on its left. The apex beats between the cartilages of the fifth and sixth left ribs, at a point about two inches below the nipple, and one inch on its sternal side. '' The lungs descend along the margins of the sternum, about two inches apart, and overlap the base of the heart, slightly on the right side and more extensively on the left : then, receding from each other, they leave a considerable portion of the right ventricle, and a lesc extent of the lower portion of the left, in immediate contact with the thoracic walls. 1 ' The right auricle is in front of the heart, at its right side and upper part. One portion of it is overlapped by the right lung, and another, principally the appendix, is in contact with the sternum. The left auricle is situated deeply behind and to the left of the heart at its upper part, opposite to the interval between the cartilages of the third and fourth ribs. The extremity of the appendix is visible in front, but, when the volume of the heart is natural, it is not in contact with the sternum, being considerably overlapped by the left lung. The auricular orifices are situated opposite to the interspace between the third and fourth ribs, and the right is rather lower down than the left."* * Hope on Diseases of the Heart, &c. pp. 3-4. THE AORTA. The Aorta, or great systemic artery of the body, consists of an arch, and descending portion ; the latter is divided into the thoracic aorta, and the abdominal aorta. The arch may be exposed by the dissection already recommended for exhibiting the heart: it extends from the base of the left ventricle to the left side of the third dorsal vertebra. In this course its convexity is directed upwards, and its summit is on a level with the body of the second dorsal vertebra ; its posterior extremity touches the spine, and in the adult subject its most prominent part is scarcely half an inch distant from the sternum. It is usually divided into three stages or portions, viz., an anterior, middle, and posterior. The anterior or ascending portion arises from the base of the left ventricle, anterior and a little to the right side of the left auriculo-ventricular opening, in front of the left side of the body of the fourth dorsal vertebra, and corresponding to the junction of the cartilage of the fourth rib with the sternum at the left side. From its origin it proceeds upwards, forwards, and to the right side, till it reaches the level of the cartilage of the second rib, at its junction with the cartilage connecting the first and second pieces of the sternum. In this course its anterior surface is related to the pericardium, which separates it from the anterior mediastinum and back of the sternum ; to the right coronary artery, the infundibulum of the right ventricle, the pulmonary artery at its origin, and to the tip of the right auricular appendix : the posterior surface corresponds to a part of the left auricle and to the right pulmonary artery : the left surface is related to the pulmonary artery immediately before it divides ; and the right surface first rests on a part of the base of the right ventricle between its arterial and auricular openings, and corresponds in the rest of its course to the descending or superior vena cava. The greatest part of 38 39 ARCH OF THE AORTA. this ascending portion is within the pericardium, the serous layer of which forms a sheath common to the aorta and pulmonary artery. This sheath also contains the right inferior cardiac nerve, which lies between these great vessels, in its course to the coronary plexus of the heart ; together with the anterior and posterior cardiac plexuses. We may observe, also, that the serous sheath extends higher up on the aorta than on the pulmonary artery, and higher up on its right than on its left side. The fibrous layer of the pericardium is lost a little higher up on the external coat of the artery, by becoming continuous on this vessel with the descending layer of the thoracic fascia. If we look at the origin of the aorta through the left ventricle, we observe a triangular opening, the area of which is more contracted than any other part of the arch is naturally found ; immediately outside this triangular opening we observe three small bulgings or dilatations, called the sinuses of Valsalva ; and above it the aorta enlarges and assumes a form nearly cylindrical, but not exactly so, on account of certain deviations to be noticed hereafter. In order to examine its connexion with the heart, we may slit up the front of it longitudinally from the left ventricle. We then find that the aorta is united to the heart in the following manner, first—internally by the continuity of their Lining membrane ; secondly —by the serous layer of the pericardium, forming a sheath passing up on the vessels as already described ; thirdly—on removing these two layers of membrane, we find, that the proper fibrous tunic of the artery does not present a straight edge to the ventricle, but that it is formed into three distinct arches, the convexities of which are directed towards the heart. Each of the convexities, or festoons, as they are also called, is separated from its fellow by a small triangular interval, the base of which corresponds to the ventricle. The origin of the vessel will thus present three inverted arches, 40 ARCH OF THE AORTA. separated from each other by three small triangular spaces. On examining the base of the left ventricle in this situation we observe the zona tendinosa, which forms the principal medium of connexion between it and the aorta. The inferior margin of this zone is imbedded in the muscular fibres of the ventricle, whilst to its superior margin are intimately and strongly attached by condensed areolar tissue, the three convexities already described. Fourthly, when we examine the small triangular intervals between the festoons, after having removed both the serous layer of the pericardium and the lining membrane of the aorta and left ventricle, we perceive that a process of fibrous membrane, prolonged from the superior margin of the zona tendinosa, fills up each of these intervals, and becomes continuous with the ' £ sclerous" or external tunic of the vessel. The description, therefore, which represents the lining membrane of the artery, and the serous layer of the pericardium as being '' in apposition" in these triangular spaces, is not correct. The processes from the tendinous zone which fill up the intervals between the three convexities may be easily demonstrated : they are by no means so strong as the rest of the ring, but though very delicate, have considerable resistance, and are separated from the serous layer of the pericardium by areolar tissue continuous with the external tunic of the artery. It is clear, however, that the lining membrane of the aorta and serous layer of the pericardium could not possibly be in apposition in that situation, where the pulmonary artery and aorta are in contact with each other, and where the serous layer of the pericardium does not dip in between these vessels. On the inside of the aortic opening we find three folds of the lining membrane forming three semilunar valves, the inferior convex margins of which are attached opposite to the convex margins of the three inverted arches ; their free or concave margins look upwards, and each of ARCH OF THE AORTA. 41 them is strengthened in its centre by a small prominent body termed the corpus Arantii, or corpus sesamoideum. When the aorta contracts, these valves are thrown away from the walls of the artery, inwards towards the centre or area of the aortic opening, and thus prevent the return of blood into the ventricle : this object is supposed to be more completely effected by the corpora Arantii, closing up at that instant the small triangular space which would otherwise exist at the common centre of approximation of the three semilunar valves. Corresponding to the outer surfaces of these valves, the aorta presents three pouches or dilatations termed the lesser sinuses of the aorta, or sinuses of Valsalva. These exist at birth, but are better marked in the adult than in the young subject, on account of the constant pressure of the blood during the contraction of the vessel. By the great sinus of the aorta is meant an enlargement of the tube at the upper part of its first stage, where the vessel begins to change its direction. It does not engage the whole circumference of the tube, but is limited to its anterior and right side. It is obviously the effect of the impulse of the blood from the left ventricle, and is therefore better marked in the old than in the young subject. If a cast of the interior of the aorta be taken in wax or plaster, it will present at its origin three distinct bulgings, corresponding to the sinuses of Valsalva ; these bulgings will appear to be separated from each other by three small fissures, which unite in the centre of the area of the artery : the same observation applies to the pulmonary artery. The middle portion of the arch passes obliquely upwards, backwards, and to the left side, so that the term transverse, usually applied to it, is not correct : it terminates on the left side of the body of the second dorsal vertebra : posteriorly it is related to the lower extremity of the trachea, to the great cardiac plexus of nerves, to the thoracic duct, and left recurrent nerve : anteriorly to 42 ARCH OF THE AORTA. the thymus gland in the early periods of Life ; to the left pneumogastric nerve, and also to the recurrent nerve, and to some small branches of the sympathetic nerve, derived from the superior cardiac nerve, which here unite with the recurrent : above it are the left vena innominata, to which it is united by a dense aponeurosis, connected below with an expansion of the fibrous layer of the pericardium, and above with a deep seated process of the cervical aponeurosis, which covers the origins of the carotid and subclavian arteries, and the arteria innominata : the origins of the great arterial trunks given off regularly from this stage of the aorta, viz., the arteria innominata, the left carotid and left subclavian, are necessarily situated above it. Beneath it, or corresponding to its concave portion, are, the left recurrent nerve, the right pulmonary artery, portion of the left auricle, the root of the left lung, sometimes the cardiac ganglion of Wrisberg, and the ligamentous chord which in intrauterine life had been the ductus arteriosus : this structure enters the concavity of the arch at a point corresponding inferiorly to the origin of the left subclavian artery from the convexity of the vessel, but a little nearer to its left side. The left recurrent nerve curves underneath that portion of the aorta which is joined by the ductus arteriosus, so that the nerve embraces within its curve, the termination of the ligamentous remains of this latter vessel as well as the concavity of the arch of the aorta. The posterior or descending portion of the arch extends from the body of the second to that of the third dorsal vertebra : posteriorly, and at its right it rests against the spine and left longus colli muscle ; on its right side also are the oesophagus, thoracic duct, f and vena azygos : cwv teriorly it is covered by the root of the left lung ; and on its left side the left lung and pleura are situated. In these different stages, besides the various relations already enumerated, the artery is surrounded by a number of dark coloured bronchial glands : when these be- Fig. 6.— Dissection to show the relations of the Vessels anal Nerves in the lower part of Neck ,¦ and some of the relations of the Arch of the Aorta and its Branches. Pericardium opened, and portions of Heart exposed. A, Eight Ventricle of the Heart. B, Pulmonary Artery and Infundibulum. C, Ascending Aorta. D, Right Auricular Appendix. E, Pericardium. F, Superior Vena Cava G, Left Pneumogastric Nerve, with loop of left Recurrent Nerve: Phrenic Nerve to their left side. H, Middle portion of the Arch of Aorta. I, Left Vena Innominata. K, Kight Vena Innominata. L, Lower end of left Internal Jugular Vein cut. M, Kight Subclavian Vein. N, Kight Internal Jugular Vein about to join Subclavian Vein. O, Arteria Innominata. P, Right Subclavian Artery crossed by Right Pneumogastric Nerve, and in loop of Right Recurrent Nerve. Q. Kight common Carotid Arteiy. R, Left common Carotid Artery. S, Left Subclavian Artery in relation with left Pneumogastric Nerve. T, Third stage of left Subclavian Artery. V, Left Scalenus Anticus Muscle, with Phrenic Nerve. W, W, First Kibs. X, X, Fifth Hibs cut across. Y, Y, Kight and left Mamillar;. Z, Lower part of Sternum, a, Thyroid Body, b, Trachea, c, Left Internal Jugular Vein cut across, d, Left Subclavian Vein, e, Clavicle cut across, and drawn downwards, f, Brachial Plexus of Nerves, g. Inferior Thyroid Artery, passing behind the cut extremity of Internal Jugular Vein, Pneumogastric Nerve, and Carotid Artery. 44 ARCH OF THE AORTA. come enlarged by disease, to which they are very liable, they occasionally produce most serious effects by their pressure on the air tubes, on the vena cava, and on the large arteries of the neck which they accompany. Taking the entire of the arch of the aorta, we will find the following parts embraced within its concavity : first, the right pulmonary artery ; second, that portion of the left auricle with which the appendix is connected ; third, the left division of the trachea ; fourth, the cardiac ganglion of Wrisberg ; fifth, the ligamentous remains of the ductus arteriosus ; sixth, the left recurrent nerve. The arch of the aorta has important venous relations : we may observe the superior vena cava, when all the vessels are moderately filled, lying to the right side of the first stage of the arch, and the left vena innominata, lying above, and very near the upper margin of the second stage. The student would do well to attend to the anatomy of these venous trunks : he will perceive after opening the pericardium, a large vein presenting a dark blue color, lying to the right of the aorta : this is the vena cava superior or descendens; it is covered, except at its most posterior part, by the serous layer of the pericardium : it is about three inches in length ; it enters the fibrous layer of the pericardium, so that about onethird of the vessel is contained within this sac; and it is situated entirely within the thorax. It is formed chiefly by the confluence of the right and left venae innominatae, or brachio-cephalic veins: this union takes place about an inch and half below the bifurcation of the arteria innominata, and corresponds anteriorly to the upper part of the second rib, near its articulation with the right side of the sternum. The vein descends nearly in a vertical direction, but slightly curved, the concavity being directed to the left, and corresponding to the right side of the first stage of the aorta ; the convexity is to the right side. It here lies anterior to the right pulmonary vessels, and enters into the upper part of the right auricle behind the 45 ARCH OF THE AORTA. auricular appendix. The vena azygos enters the cava at its posterior surface, just before this large vein passes into the pericardium. The other veins which pour their blood into the superior cava, are, the right inferior thyroid and internal mammary veins, the thymic, pericardial, mediastinal, and right superior phrenic : these veins usually enter the vessel at its commencement, and in its extra-pericardial stage. In this stage the vein has numerous relations : behind it we observe the vena azygos, a portion of the trachea, the right vagus nerve, some lymphatic glands, and loose areolar tissue ; to the outside, we have the right phrenic nerve, the right pleura and lung ; anteriorly, the remains of the thymus gland, some areolar tissue belonging to the anterior mediastinum, and the phrenic nerve ; and to its left or inner side we have the arch of the aorta. The arch of the aorta being in close relation both to the anterior and posterior walls of the chest, as well as to its interior, and being surrounded by numerous cavities and tubes, it is evident that an aneurismal tumour affecting this portion of the vessel may open in a great variety of situations. We frequently find it absorbing the sternum at its junction with the cartilage of the second or third rib of the right side, and pointing, or even opening anteriorly. It has been known to burst into the right auricle of the heart, into the pericardium, the pulmonary artery, the trachea, bronchial tubes, and air cells ; into the mediastinum, oesophagus, right and left pleurae, and into the spinal canal ; also to press upon, and obstruct the thoracic duct, or obliterate the subclavian or common carotid artery. In some cases the tumor ascends behind and above the clavicle and simulates subclavian or carotid aneurism ; in other cases its pressure anteriorly has been known to dislocate the clavicle, and the occurrence of dyspnoea, aphonia, and dysphagia during its progress can be accounted for by pressure on the air passages, recurrent nerve, and oesophagus. 46 BRANCHES OF THE ARCH OF THE AORTA. Mr. Smith has described a very remarkable case of aneurism of the ascending portion of the aorta, the front of which was divided by the pulmonary artery into two portions, one of which projected into the right ventricle, and the other into the left. From each of these cavities the sac was divided only by a very delicate membrane, that must have been absorbed, had the patient lived a very little longer.* Development of the Aorta. —This vessel is formed after the portal system, with which it is connected by a dilatation which is the rudiment of the future heart. In the young child it lies nearer the spine than in the adult, on account of the larger size of the thymus gland which Lies in front of it, and the comparatively imperfect development, at this period of life, of the trachea and bronchial tubes, which are situated behind it : but as the right bronchus becomes developed, and the thymus gland absorbed, the arch of the aorta advances nearer to the sternum. We also find that in the young subject the arch is situated higher up than in the adult : this is owing to the thorax of the child having less proportional height ; and for the same reason the arch is higher in the adult female than in the male. In some cases we find it unnaturally high, independently of the age or sex of the individual. In the old subject the swell of the arch is considerably increased by the development of the great sinus. If a vertical section be made of the arch of the aorta, the convexity of the arch wil be found to be thicker than the concavity. BRANCHES OF THE ARCH OF THE AORTA. From the Arch of the Aorta five branches usually arise, viz., Right and Left Coronary, . . . . / Fr ° m the ascending ' ) portion or the arch. Arteria Innominata, Left Carotid, ( From the middle porand Left Subclavian, . . . . ( tion of the arch. * Dublin Journal, vol, ix. 47 ARTERIA INNOMINATA. The anatomy of the two coronary arteries has been already described. ARTERIA INNOMINATA. The Arteria Innominata, or Brachio-cephalic artery, arises from the arch of the aorta at the commencement of its second stage, and corresponding to the termination of the great sinus of Morgagni; it lies on the front of the trachea, a little to the left side of the middle line, and on a level with the cartilage of the second rib. From its origin it proceeds upwards, backwards, and to the right side, to terminate behind the right sterno-clavicular articulation by dividing into the right subclavian and right carotid arteries. If a needle be passed directly backwards and immediately on a level with the top of the sterno-clavicular articulation of the right side, it will be found to pass between the two origins of the sterno-mastoid muscle and through the angle formed by the bifurcation of the arteria innominata into the right subclavian and carotid arteries. The arteria innominata varies in length from an inch to about an inch and a half : it may be dissected either from the neck or from the interior of the thorax ; and the student is recommended to adopt both of these methods. On dissecting from the neck downwards to the thorax the following parts will be found related to the artery. Anteriorly, after removing the integuments and fascia of the neck, we see the sternal origin of the sternocleido-mastoid muscle, the first bone of the sternum, the sterno-clavicular articulation, and the sterno-hyoid and sterno-thyroid muscles : near the origin of the artery the left vena innominata, with which it is connected by the descending layer of the thoracic fascia, crosses in front of it ; and still higher up, in the young subject, the thymus gland. Posteriorly, the artery rests upon the trachea : on its left side we find the middle and inferior thyroid veins, and occasionally a middle thyroid artery, which separates it from the left carotid. On its right side, and on a plane 48 ARTERIA INNOMINATA. anterior to it, we observe the right vena innominata, and between the two vessels the pneumogastric nerve runs in close relation to the bifurcation of the artery : still more externally than the vagus, the phrenic nerve may be seen lying behind the right vena innominata; and in its passage to the outside of the superior vena cava, still lower down, the vessel is accompanied by the inferior cardiac nerve or nerves : the superior part of the parietal division of the right pleura is situated inferior and external to the artery. We have spoken of a fascia in connexion with the left vena innominata, as it passes across the arteria innominata : this fascia will be found to connect not merely these two vessels with one another, and to afford them coverings, but by a deeper seated process to connect the artery with the trachea, to which latter tube also it furnishes an investment. This fascia has been described by Sir A. Cooper as enveloping these vessels, connecting them with the bones which form the opening of the thorax, and continuous with the fibrous portion of the pericardium. He also describes this fascia as continuous above with the deep seated fascia of the neck described by Burns.* Mr. Godman of Philadelphia also, described this the thoracic fascia, and its continuity with the pericardium and fascia of the neck.f The anatomy of the great venous trunks in relation to the arteria innominata, next demands our attention. The left vena innominata will be seen crossing obliquely above the middle portion of the arch of the aorta, in front of the left carotid, trachea, and arteria innominata, downwards and towards the right side of this latter vessel, a distance of about three inches. The right vena innominata will be seen passing in a more vertical direction, * Anatomy of the Thymus Gland, p. 24. t Anatomical Investigations by John D. Godman, in Philadelphia Journal, 1824. 49 ARTERIA INNOMINATA. but taking a shorter course, and ranging below the level of the first stage of the right subclavian artery. The two venae innominatse unite to form the vena cava descendens, upon a plane anterior and to the right of the arteria innominata, and about half an inch below its bifurcation. An intervascular space will be found in this situation, formed superiorly and internally by the trunk of the arteria innominata and part of the right subclavian artery ; inferiorly and to the right side by the right vena innominata ; internally the interval is closed by the termination of the left vena innominata in the vena cava descendens ; and superiorly by the internal jugular uniting with the subclavian vein to form the right vena innominata. This interval will be found to contain a quantity of loose areolar tissue, the vagus nerve, and the origin of its recurrent branch or inferior laryngeal nerve, which may be seen in this situation passing underneath the right subclavian artery: the inferior cardiac nerve will be found here also : the layer of fascia, already described as continuous with the deep layer of the cervical fascia, covers all these parts. It is this space which the surgeon's aneurism needle must traverse in the operation of tying the arteria innominata. If the dissection of the artery be made from the chest, the apex of the right lung should be drawn downward ; the finger may be then passed upwards into the summit of the supra-clavicular region, so as to pass behind the middle stage of the right subclavian artery ; it will be then found that the parietal layer of the pleura will ascend from the thorax into this region, forming the apex of the cone of the pleura. If the finger be now pressed internally and anteriorly, the under surface of the arteria innominata may be felt, through the pleura. If a vertical section of the arteria innominata and arch of the aorta be made, the right wall of the former vessel will be observed to form nearly a directly continuous surface with the convexity of the arch ; whilst its left wall will be seen forming a spur-like projection E 50 LIGATURE OF THE ARTERIA INNOMINATA. into the aorta : a considerable amount of the column of blood issuing from the heart will be thus directed into the arteria innominata. The same observation will apply to the origins of the left carotid and left subclavian arteries, though in these vessels the arrangement is not so distinctly seen. Operation of tying the arteria innominata. —This operation has been performed in about ten cases ; in nine for subclavian aneurisms ; and in one, where hemorrhage took place after ligature of the subclavian : all these cases were attended with fatal results. LIGATURE OF THE ARTERIA INNOMINATA. No. Operator. Dftto of Operation liesults and Observations. 1 MottofNewYork,... 1818 (Death on the 26th day, from < hemorrhage: ligature came (_ away on the 14th day. 2 Norman of Bath,... 1824 Death. 3 Graefe of Berlin,... 1829 f Death on the 67th day, from ¦s hemorrhage: ligature came away on the 14th day. 4 Arendt, a Russian) Surgeon, ) 1830 Death on the 8th day, from i inflammation of the lungs, pleura, and aneurismal sac. 5 Bland of Sydney,) New South Wales,) 1832 (Death on the 18th day, from ( hemorrhage. 6 Hall of Baltimore,... 1833 / Death on the 5th day, from J hemorrhage. Coats of the j artery were diseased. 7 A Parisian Surgeon —case alluded to I by Dupuytren, f Clinique Chirm - -? gicale, vol. iv. p. I 611. J 1834 Death from hemorrhage. 8 Lizars of Edinburgh, 1837 (Death on the 21st day, from \ hemorrhage. 9 Hutin, a French) Surgeon, ) 1842 (Death in 12 hours, from ( hemorrhage. 10 Cooper of SanFrancisco! 1859 Death on the 9th day. 51 LIGATURE OF THE ARTERIA INNOMINATA. In the year 1831, Professor Porter of this city exposed the artery for the purpose of including it in a ligature, but finding it diseased throughout its entire length, he thought it advisable not to tie the vessel : the wound was therefore closed. After some time the tumor had undergone considerable diminution in size, and when the patient left the hospital it had become nearly consolidated, and the pulsation had almost ceased.* A nearly similar case occurred in the practice of Mr. Key. The operator attempted to pass the ligature round the arteria innominata, but did not persevere. On the 18th day the patient was going on tolerably well, but the sac increasing in size, pressed upon the trachea, and stopped respiration. The patient died on the 23rd day after the operation. + In none of these cases did the sudden abstraction of blood from the head, neck, and right upper extremity, produce any serious consequence, or even inconvenience ; though, as Dr. Mott observes, " to intercept suddenly one fourth quantity of blood so near the heart, without producing some unpleasant effect, no surgeon, a priori, would have believed possible. The profession were not however, altogether unprepared for these important results ; for cases were occasionally observed in which the obstruction of considerable trunks supplying the brain, did not appear to be followed by any alarming consequence. Thus Pelletan dissected a case in which the right subclavian, right carotid, and termination of the arteria innominata, had been completely impervious during life, without having produced any serious consequence ; and Mr. W. Darrach has related a similar case, except that the right subclavian was in this instance pervious. Mode of performing the operation —The patient should lie on his back on a table, with both the shoulders * Dub. Jour. 1832, vol. i. t Crisp on " Diseases of the Blood Vessels," p. 200. E 2 52 LIGATURE OF THE ARTERIA INNOMINATA. thrown forwards, the right being at the same time drawn forcibly downwards, and the head leaning backwards, and to the left side. An incision should then be made transversely from the external margin of the sternocleido-mastoid muscle parallel to and above the clavicle, till it terminates opposite the trachea : a second incision is then to be made along the anterior margin of the sterno-cleido-mastoid muscle, about three inches in length, and terminating inferiorly at the internal extremity of the preceding incision. On raising the flap, the sternocleido-mastoid muscle is brought into view : under this a director should be conveyed from within outwards, keeping it close to the muscular fibres, in order to exclude the veins and nerves in this situation. On this we divide the sternal, and part (almost all according to Guthrie) of the clavicular origin of the muscle. We then, by a similar proceeding, divide successively the sterno-hyoid and sterno-thyroid muscles of the right side above the sternum. With the nail, or handle of the scalpel, we should now tear through the dense aponeurosis covering the carotid artery, and in the same way dissect the small veins in this situation, not using the cutting edge of the knife as long as we can avoid it. When the carotid artery is exposed, it will serve (unless there be an irregularity) to conduct the finger to the arteria innominata, which, on account of the patient's position, will be drawn up from the thorax. The left vena innominata should now be depressed, and the aneurism needle passed from without inwards and upwards, keeping it close to the vessel to avoid the pleura, and the pneumogastric and inferior cardiac nerves, all of which are on its right side. By tying the artery near its termination, there is more room left for the formation of an internal coagulum. After the needle is passed underneath the vessel, considerable difficulty is often experienced in depressing its handle, so as to raise its point sufficiently on the opposite side : it became desi- LIGATURE OF THE ARTERIA INNOMINATA. 53 rable, accordingly, that some means should be contrived to obviate this difficulty, and facilitate the conveyance of the ligature in deep situations. For this purpose a very ingenious instrument has been invented by Mr. L'Estrange of this city. Two other methods have been proposed to effect a ligature of the arteria innominata. The first is to trepan the upper piece of the sternum, and tie this vessel below the left vena innominata : this is a most objectionable proceeding. The second has been proposed originally by Dr. O'Donnell of Liverpool,* and subsequently recommended by Velpeau : the following is an abridged account of it; the operator stands at the left side of the patient's head; an incision is to be made through the skin, commencing at the internal margin of the left sterno-mastoid muscle, and carried downwards and towards the right side for the extent of about two inches. The next incisions should divide the two layers of fascia in this situation, so as to expose the trachea. The middle thyroid artery, if present, and veins, are to be pushed aside, and, if necessary, tied. The index finger is now made to glide between the right sterno-hyoid muscle and the trachea, in order to detect the arteria innominata. The operator then passes a curved staff with great caution and management from before backwards, between the artery and vena cava superior. The posterior surface of the vessel is next to be denuded, and raised with the staff in the same cautious manner. Guided by this, the " stylet port fil," should be introduced from left to right, and from behind forwards. Velpeau says, that this operation is incontestibly more simple, more rational, and less dangerous than any other; and has, moreover, this advantage, that the same proceeding will serve for the ligature of either of the subclavians in the first stage, or either of the carotids near its origin. Unfortunately, however, no matter how simple the steps * Cyclopaedia of Practical Surgery, vol. i. p. 260. 54 COMMON CAROTID ARTERIES. of the operation may be made for including the arteria innominata in a ligature, the results of the operation have been so uniformly fatal that the surgeon has nothing to encourage him in its adoption. COMMON CAROTID ARTERIES. The common carotid of the right side arises from the arteria innominata at the superior outlet of the thorax, behind, and on a level with the upper portion of the right sterno-clavicular articulation, and between the sternal and clavicular origins of the right sterno-cleidomastoid muscle. On the left side it arises within the thorax, from the arch of the aorta. As the two common carotid arteries ascend in the neck they separate from each other, and terminate one on either side opposite the superior margin of the thyroid cartilage, below the great cornu of the os-hyoides, and at a point corresponding to about the third cervical vertebra, about an inch below the angle of the lower jaw. In this course they are separated inferiorly by the trachea and oesophagus, and superiorly, at a greater distance, by the larynx and pharynx. Each of the carotid arteries is contained within a fibrous sheath, formed by a process of the deep cervical fascia ; the internal jugular vein and pneumogastric nerve are also contained within it. The tendinous centre of the omohyoid muscle may be seen crossing in front of the sheath, and attaching itself intimately to it, nearly opposite the cricoid cartilage. The common carotid of each side may be thus considered as divided into two stages —one below the omo-hyoid muscle, the other above it. We shall first describe the relations of the right common carotid artery in these two stages, then the course and relations of the left, and afterwards point out the differences between them. First or inferior stage of the right Common Carotid. — This vessel, as has been stated, arises from the arteria 55 COMMON CAROTID ARTERIES. innominata immediately behind the upper part of the sterno-clavicular articulation, and inclines a little backwards as it ascends in the neck. In this stage it is covered anteriorly by the integuments, by the platysma myoides (except in the immediate neighbourhood of its origin from the innominata) ; —more deeply by the sternomastoid enclosed within a proper sheath of the cervical fascia ; by the sterno-hyoid, and sterno-thyroid muscles, and still deeper, by branches of the descendens noni nerve, and by the cervical fascia. When the sternomastoid muscle is largely developed, its sternal portion considerably overlaps the artery after its origin from the arteria innominata. Internally it is related to the trachea, oesophagus, and thyroid gland, which often overlaps it ; and to the larynx, and inferior portion of the pharynx. Externally it is related to the internal jugular vein and pneumogastric nerve, which latter lies deeply concealed between the artery and vein—the nerve, artery and vein being contained in a common sheath of fascia : sometimes a distinct septum of the same structure, passes from the front to the back part of the sheath, so as to separate the artery from the vein. Posteriorly, it is crossed by the inferior thyroid artery, which separates it from the vertebral : the sympathetic nerve and its branches descending, and the recurrent nerve ascending, and some loose areolar tissue lie also behind the common carotid, and separate it from the spine and longus colli muscle. First or inferior stage of the left Common Carotid. — The left carotid artery arises from the arch of the aorta. The first stage of this artery may be divided into two portions—a thoracic and cervical : the thoracic extends from the origin of the vessel from the arch of the aorta, between the origins of the arteria innominata and left subclavian, and opposite to the second dorsal vertebra, to the upper and back part of the left sterno-clavicular articulation. This portion is therefore situated within 56 COMMON CAROTID ARTERIES. the cavity of the thorax. Anteriorly, its origin is covered by the sternum, sterno-clavicular articulation, sternohyoid, and sterno-thyroid muscles, and the commencement of the left vena-innominata ; and higher up, in its second or cervical portion, it has the same anterior relations as the artery of the right side. Internally it is related to the arteria innominata, trachea, oesophagus, and thymus gland which usually overlaps it. In close relation to it externally we find the internal jugular vein, and the pneumogastric nerve which lies concealed deeply between the artery and the vein ; the phrenic nerve, and the upper part of the left pleura and lung are also related to its outer side : the thoracic duct lies posterior to the artery at its origin, but afterwards passes to its external side. Posteriorly, it first rests on the left side of the trachea, and on the oesophagus, and afterwards upon parts similar to those which constitute the posterior relations of the right common carotid. Higher up it is separated from the spine and longus colli muscle by the sympathetic nerve and its cardiac branches, as at the right side. These are the usual relations of the left carotid, but they may vary, or their number be increased in consequence of irregularities. Hence it appears, that the right and left common carotids differ in the following respects in their first stage,—The right comes from the arteria innominata, and the left from the arch of the aorta—consequently the left is longer than the right. The left lies within the cavity of the thorax, on the front of the trachea and oesophagus, and is intimately connected with the thoracic duct. On the right side the internal jugular vein sepa* rates from the artery inferiorly, passing outwards from its external surface ; a small vascular triangle is thus formed, bounded internally by the carotid artery, externally by the internal jugular vein, and inferiorly by the first stage of the subclavian artery. On the left side the 57 COMMON CAROTID ARTERIES. jugular vein overlaps the outer edge of the carotid artery inferiorly, so that no such vascular triangle exists. The student should now examine the large venous trunks which are related to the thoracic portion of the left carotid artery. The left internal jugular vein will be seen descending along the outer side of the artery, and in this situation uniting with the left subclavian vein to the right side of, and on a plane anterior to, the left subclavian artery, to form the left vena innominata. When the jixgular vein is distended it overlaps the outer part of the left common carotid artery in this situation. The origin of the left vena innominata will be therefore anterior to a point corresponding to the narrow interspace between the lower parts of the thoracic portions of the left carotid and subclavian arteries : it then passes obliquely in front of the left common carotid, the trachea and arteria innominata, and unites, as already described, with the right vena innominata to form the vena cava descendens. In its course the left vena innominata receives the inferior thyroid, the left internal mammary, left phrenic, pericardial, and anterior mediastinal veins. The left vena innominata is retained in its position by a thin layer of the descending portion of the thoracic fascia. Second or superior stage of the common carotid artery. —In this stage the artery of each side lies close to the bodies of the cervical vertebrae, resting posteriorly on the longus colli muscle and sympathetic nerve : internally it is related to the larynx, pharynx and thyroid gland : externally its relations are the same as in the inferior stage. In front it is covered by the integuments, platysma myoides, and cervical fascia : the sterno-mastoid branch of the superior thyroid artery crosses it anteriorly, whilst the superior thyroid itself descends on a plane anterior and internal to it. The common carotid artery will be found related to 58 COMMON CAROTID ARTERIES. two triangular regions in the neck, —namely, the anterior inferior, and the anterior superior : the first is bounded internally by the middle line, which may be considered as the base ; the two other sides are situated externally, —the lower side formed by the sternal origin of the sterno-cleido-mastoid muscle, and the upper by the an- Fig. 7.— Dissection to show part of the course of the External Carotid Artery, of some of its branches; and part of the course of the right Subclavian Artery. I, Occipital portion of Occipito-frontalis Muscle. 2, Insertion of Stemo-mastoid Muscle —aponeurotic connexion between it and Trapezius removed. 8, Lobe or Lobulus of the Ear. 4, Itamus of the lower jaw. 5, Masseter Muscle. 6, Upper portion of Trapezius Muscle. 7, Splenitis Muscle, 8, Levator Anguli Scapula;. 9, Sterno-mastoid. 10, Great Cornu of the Os-hyoides,—the Lingual Artery getting above it to piss deeper than the Hyo-glossus Muscle. 11, Mylo-hyoid Muscle. 12, Anterior belly of Digastric Muscle—the posterior has been removed. 13, Lowerpart of Trapezius. 14, Scalenus Modius and Posticus. 15, Relation between the Omo-hyoid and Sterno-mustoid Muscles. 16, Anterior belly of the Omo-hyoid. 17, Posterior belly of Omo-hyoid. 18, One of the Nerves of the Brachial Plexus. 19, Posterior Scapular Artery given oif in this case by Subclavian Artery behind Anterior Scalenus. 20, Anterior Sculenus Muscle. 21, Portionof clavicular origin of Sterno-mastoid. 22, Sternal origin of Sterno-mastoid Muscle. 23. Thyroid Gland. 24. Aponeurotic junction between the Trapezius and Deltoid Muscles. 25, Clavicle. 26, Deltoid Muscle. 27. Small Arterial twig. Lower A, Bifurcation of Common Carotid Artery Upper A, External Carotid Artery. B, Subclavian Artery after having passed behind the Anterior Scalenus Muscle, a, Superior Thyroid Artery. b, Facial or External Maxillary Arteiy: Submaxillary Gland removed. The Inferior Palatine Artery is seen behind b. c. Inferior Mental or Sub-mentuI Artery, d, Transversalis Faciei Artery. e, External Carotid near its termination: lower part of Parotid Gland removed, f, Supra-scapular Artery crossing the Anterior Scalenus Muscle. 59 VEINS OF THE NECK. terior belly of the omo-hyoid; the apex is situated externally at the decussation between these two muscles. The carotid artery will be seldom found contained fairly within this triangular region ; in an emaciated subject a small portion of the vessel may lie within it, corresponding to the apex ; but in a muscular subject the artery lies under cover of the sterno-mastoid muscle, until it has passed into the anterior superior lateral triangle. This latter space is bounded superiorly by the posterior belly of the digastric and the stylo-hyoid muscles ; this may be considered the base : externally by the sterno-mastoid muscle, and internally by the anterior belly of the omo-hyoid : the apex is situated inferiorly at the point of separation between these two muscles. It would appear from the preceding account, that the trunk of the common carotid artery may be effectually compressed against the spinal column, so as to prevent hemorrhage in case of a wound of the trunk or its branches. Such pressure, however, could not in a great majority of cases be maintained sufficiently long in consequence of the great suffering produced by pressure on the adjacent nerves ; still it is often of the greatest importance to know a means of arresting the flow of blood, until the surgeon shall be in attendance to perform the operation of tying the wounded artery. VEINS OF THE NECK. Before we proceed to speak of the operation of tying the trunk of the common carotid artery, the student is advised to study the anatomy of the large veins of the neck. The External Jugular Vein will be seen commencing behind and close to the angle of the lower jaw, and to the anterior border of the sterno-mastoid muscle : it is in fact a continuation of the temporo-maxillary vein : it then crosses the sterno-mastoid, running obliquely downwards and backwards, and covered by the Fig. 8.—Dissection to show the relations of the Nerves, Arteries and Veins of the right side of the neck. A, Arteria Innominata. B, Subclavian Artery crossed by the Vagus Nerve. C, Common Carotid Artery having the Vagus Nerve to its outside. 1), E, External Carotid Artery. F, F, Internal Jugular Vein crossed by branches of the Cervical Plexus, which join the Descendeus Noni Nerve. G, Facial Artery. H, Occipital Artery in relation with Internal Jugular Vein, and Ninth Nerve. I, Superior Thyroid Artery. K, Subclavian Artery in relation with Brachial Plexus of Nerves. L, Part of Subclavian Vein lying on Scalenus Anticus Muscle. M, Transversalis Colli Artery. O, Union of External Jugular and Posterior Scapular Veins. P', Transversalis Humeri Artery. Q, Q, Q, Branches of Brachial Plexus of Nerves. R, R, Omo-hyoid Muscle. S, Trapezius Muscle. T, Clavicle. V, Cluvioular origin of Sterno-mastoid Muscle Y, Scalenus Posticus Muscle. Z. Splenius Muscle. a. Cervical Plexus assisting in forming the Phrenic Nerve which descends on the Scalenus Anticus Muscle. b, Spinal Accessory Nerve, which pierces the Sterno-mastoid Muscle. c, Internal Carotid Artery, with Pescendens Noni Nerve lying on it. d. Vagus Nerve between the Carotid Artery and Internal Jugular Vein, e, Ninth Nerve, f, Lingual Artery passing under the Hyo-glossus Muscle. g, Mastoid portion of Sterno-mastoid Muscle, h, Genio-hyoid Muscle, i, Mylo-hyoid Muscle cut and turned forwards. 1, Internal Maxillary Artery passing behind the neck of the lower jaw. m, Sterno-thyroid Muscle out across, n, Stemo-hyoid Muscle cut across, p, Sympathetic Nerve behind and between Carotid Artery and Jugular Vein, r, Parotid Duct. 61 VEINS OF THE NECK. platysma-myoides muscle, until it reaches about the centre of the clavicle ; it then sinks behind and underneath the posterior border of the sterno-mastoid and terminates in the subclavian vein. It pierces the cervical fascia in two situations, —at its origin near the angle of the jaw, and at its termination above the clavicle. In its intermediate course it is situated immediately under cover of the platysma, and is comparatively superficial. Sometimes a large branch of communication will be seen passing from the external to the internal jugular vein below the angle of the jaw, and close to the sub-maxillary gland Along the anterior border of the sterno-cleidomastoid muscle, a large vein, the Anterior Jugular, will be observed passing down towards the sternum and covered by a portion of the cervical aponeurosis : it lies in front of the sterno-hyoid muscle, and close to the upper margin of the sternum it passes outwards behind the sterno-cleido-mastoid muscle, runs for a short distance along the upper and back part of the clavicle across a space filled with loose areolar tissue, situated between the lower part of the sterno-mastoid muscle anteriorly, and the insertion of the scalenus anticus posteriorly, and finally terminates in the subclavian vein internal to the entrance of the external jugular vein, or in common with this vessel: a transverse branch of communication will sometimes be found connecting the two anterior jugular veins immediately above the sternum. The Internal Jugular Vein should be carefully studied in relation to the common carotid artery of each side. These vessels are contained within a sheath formed by the cervical aponeurosis, and as has been already stated, the vein lies upon the outer side of each of the common carotid arteries in their two cervical stages : there is, however, at the lower portion of the artery of the left side, a closer connexion between it and the internal jugular vein than at the right. Frequently a well-marked aponeurotic septum will be found running from the ante- 62 LIGATURE OF THE COMMON CAROTID. rior to the posterior portion of the sheath, so as to divide it into two canals, the inner containing the artery, the outer containing the vein and vagus nerve. LIGATURE OF THE COMMON CAROTID ARTERY. This operation has been performed on several occasions, and under various circumstances. The four following heads will include these different operations :— 1. The common carotid has been tied for wounds or ulceration of this vessel or of its branches. 2. It has been tied according to the Hunterian method, i. e. between the aneurismal tumor and the heart, in cases of aneurism of the trunk of the artery itself, or of its branches. 3. The artery has been tied according to the method proposed by Brasdor and Dessault, i. e. beyond the aneurismal tumor, —between it and the capillary system of vessels, for the cure of aneurism of the trunk of the artery itself. 4. Upon the same principle as that adopted by Brasdor, the common carotid has been tied beyond the tumor, in cases of aneurismal disease of the arteria innominata including the origin of the right carotid. This plan was first recommended by Mr. Wardrop. That the direct flow of blood through the common carotid artery may be arrested without impairing the functions of the brain, has been abundantly proved by dissection. In a man who died seven years after aneurism of the neck, Petit found the common carotid obliterated. Haller has noticed a similar occurrence. Baillie found it obliterated on one side and contracted on the other, and Jadelot is said to have observed a case in which both common carotids were obliterated. By the experiments of Galen and Valsalva upon dogs, and by the success of the operation on the human subject, the same fact has been demonstrated. This will not appear surprising, if LIGATURE OF THE COMMON CAROTID. 63 we recollect that the brain is supplied by four large arteries, viz. : —the two internal carotids, and the two vertebrals arising from the subclavian arteries, and that these anastomose in the freest manner by large branches at the base of the brain, independently of their extensive communication by smaller branches. Mr. Hodgson is inclined to believe, that the brain in its natural state, receives a larger quantity of blood than is requisite for the due performance of its functions ; having found that in a dog whose two carotids had been tied, the aggregate of the anastomosing tubes was not equal to the calibre of one carotid artery in its natural state. The trunk of the common carotid has been tied in cases of wound or ulceration of this vessel or of its branches. Hebenstreit relates the first case on record, in which it was tied in the human subject, in consequence of its having been divided during the removal of a schirrous tumor : the operation succeeded. In a second case Mr. Abernethy tied the common carotid for hemorrhage from a lacerated wound : and though the patient did not recover, yet his death was not occasioned by an insufficient quantity of blood being transmitted to the brain. My colleague, Mr. Ellis, one of the surgeons of the Jervis-street Hospital, tied this artery with complete success in an individual who, in an attempt to commit suicide, had opened some of the branches of the artery by an incision which extended from the angle of the jaw towards the chin. * Sir A. Cooper was the first who tied the artery for the cure of aneurism, according to the Hunterian method, and this operation has since been repeatedly performed, and with considerable success. The same operation has also been performed for aneurism by anastomosis of the orbit, by Travers and Dalrymple. It was also tied successfully by Professor Pattison, for a large * Ellis' Clinical Surgery, p. 25. t Med. and Phys. Jour. vol. 48. 64 LIGATURE OF THE COMMON CAROTID. aneurism by anastomosis of the cheek ;f and both common carotids were tied successfully by Dr. Mussey of New Hampshire in America, for aneurism by anastomosis on the crown of the head :* between the two operations there was an interval of only twelve days : the tumor was subsequently removed, and the patient recovered. It has been observed that when this vessel is the seat of aneurism, it frequently occurs at its bifurcation, where there exists even in health a transverse dilatation. The operation of tying the common carotid artery beyond the aneurismal tumor, i. e. at the capillary side of the aneurism, has been performed by Deschamps and Sir A. Cooper, but with fatal results. In 1825 Mr. Wardrop performed this operation with success, f The common carotid has also been tied in accordance with the proposal of Mr. Wardrop. Acting on the suggestion of Mr. Wardrop, Mr. Evans of Derbyshire tied the artery in a case of aneurism of the arteria innominata involving the origin of the right common carotid ; this operation was successful. J This vessel was also tied for aneurism of the arteria innominata by Dr. Hutton, one of the surgeons of the Richmond Hospital, in June, 1842 : the patient died on the seventy-sixth day. There was no union of the coats of the artery where the ligature had been applied. § This artery has been tied about eleven times for aneurism of the arteria innominata, upon the principle advocated by Mr. Wardrop. Two out of the eleven recovered; the rest died. The operation of including the Common Carotid Artery in a ligature may be performed either in its inferior stage below the omo-hyoid muscle, or in its superior stage, above this muscle. * Amer. Jour. Med. Sciences for February, 1830. t Trans, of Med. Chir. Soc. 1825. t Lancet, 1828. § Dublin Pathological Reports, 1842, p. 197. LIGATURE OF THE COMMON CAROTID. 65 The operation of tying the Common Carotid Artery in its inferior stage. An incision should be made through the integuments along the internal margin of the sternomastoid muscle, for the extent of about three inches above the clavicle. In most cases a vein may be observed descending along the anterior margin of the sterno-mastoid muscle communicating with the facial vein above, and with the thyroid plexus of veins, or the subclavian vein below : care must be taken not to injure this. A portion of the fascia at the lower part of the incision, should next be raised in the forceps, and divided in a horizontal direction : through the opening thus made a director should be introduced from below upwards in the line of the first incision, and the fascia slit up on it as far as may be necessary. The lips of the wound are now to be separated by retractors, the sterno-mastoid muscle being drawn outwards, and the sterno-hyoid and stern o-thyroid inwards. The sheath of the vessels will be thus exposed, and on the front of it may be seen the internal branch of the descendens noni nerve, which should be drawn inwards, and the sheath divided in the same cautious way as the fascia. A ligature is now to be passed round the artery, directing the needle from without inwards, in order to avoid the jugular vein, which sometimes suddenly swells out during expiration, and then contracts during inspiration. As the vein fills at both its upper and lower extremity, an assistant should in such case compress it both at the upper and lower angle of the wound. In very many cases the vein, so far from giving any trouble, is not even observed during the whole of the operation. In a case operated on by Dr. Browne, of the Navan County Infirmary, "the internal jugular vein did not appear, nor was it a source of the slightest inconvenience during the operation." In a similar case related by Mr. Hodgson, "the jugular vein afforded no trouble in the operation ; it was not even seen." Mr. Read of Dublin, whose experience is very considerable, is reported by Mr. Har- F 66 LIGATURE OP THE COMMON CAROTID. grave to have said that " in all the operations he performed, or assisted in, on this vessel, the vein was not found to interfere with the operation, nor was it even seen."* The existence of the fibrous septum extending from the anterior to the posterior part of the sheath, and thus separating the artery from the vein, may explain this fact. Care is to be taken to avoid including the pneumogastric nerve, which lies behind and between the vessels : the nerve should be drawn outwards with the vein. The sympathetic and recurrent nerves are behind the sheath, and there is comparatively little danger of including them in the ligature. In operating on the left side, the proximity of the thoracic duct is to be borne in mind. Sedillot's operation. He makes an incision two and a half inches long, which passes from the internal end of the clavicle obliquely upwards and outwards in the direction of the interval between the two origins of the sternocleido-mastoid muscle. The skin, platysma, and deep fascia are successively divided, the two portions of the muscle drawn apart with the edges of the wound, and the internal jugular vein is reached inside the anterior scalenus and phrenic nerve. The sheath of the vessel is opened, the vein drawn to the outside, and the artery sought at its internal side. The decided objection to this operation is that there is the greatest possible danger of wounding the internal jugular vein, which lies at the bottom of this incision, and which if distended, as it is most likely to be during the operation, from the struggles of the patient or from other causes, will present itself in such a maimer as to obscure the artery from the view of the surgeon. In a word, the operator instead of getting into that compartment of the sheath which contains the artery, gets into that which contains the vein. Operation of tying the Common Carotid in its superior stage. The first incision should commence a little * Operative Surgery, p. 68. 67 EXTERNAL CAROTID ARTERY. beneath the angle of the lower jaw, and terminate on the side of the cricoid cartilage. This incision will divide the skin, platysma myoides, and cervical fascia, and expose the sheath of the vessels with the descendens noni nerve lying on its front. The nerve is to be drawn outwards, and the sheath opened in the cautious manner already described. The artery being now exposed, the needle is to be carried around it from without inwards, taking care (as in the inferior operation) not to wound the jugular vein, nor include the pneumogastric nerve. It should also be remembered that the communicans noni, a branch of the cervical plexus, not unfrequently descends within the sheath of the vessels between the carotid artery and jugular vein. Having arrived opposite the superior margin of the thyroid cartilage, and below the great cornu of the oshyoides, the common carotid artery of each side divides into the external and internal carotid arteries. At the point of bifurcation the artery generally presents a transverse dilatation, so that the vessel appears enlarged in this situation. This enlargement Lies anterior to the longus colli and rectus capitis anticus major muscles, corresponding to about the third cervical vertebra, and in the adult to a point about one inch below the angle of the lower jaw. In old age, from the absence of the teeth, the angle of the jaw is removed still farther above the bifurcation of the common carotid; in infancy also, before the appearance of the teeth, the angle of the lower jaw is situated at a comparatively considerable distance above the division of the common carotid artery. EXTERNAL CAROTID ARTERY. This artery usually arises nearly opposite the superior margin of the thyroid cartilage ; it is situated, until crossed by the digastric and stylo-hyoid muscles, in the anterior superior lateral triangle of the neck. It derives f 2 68 EXTERNAL CAROTID ARTERY. its name, not from its position with regard to the internal carotid at the origin of these vessels from the common trunk, for in this situation the external carotid is the more internal of the two, but because its ultimate destination is to those parts external to the cranium, whilst the destination of the internal carotid is principally to the parts contained within this cavity. The external carotid may be divided into two stages, the first extending from its origin to the lower part of the parotid gland; and the second where the artery lies within the substance of this gland. After its origin it ascends towards the submaxillary gland, but afterwards turns outwards, and plunges into the parotid gland, through which it ascends as far as the neck of the inferior maxillary bone, where it terminates by dividing into the temporal and internal maxillary arteries. In this course it describes a curvature, the convexity of which looks upwards, backwards, and inwards towards the tonsil. In its first stage, before it reaches the parotid gland, its cutaneous surface is at first comparatively superficial, being covered by the skin, platysma myoides and cervical fascia ; by the union of the temporo-maxillary with the facial vein at the commencement of the external jugular ; it is then covered a little higher up by the posterior belly of the digastric muscle, the stylo-hyoid muscle, and the hypo-glossal nerve. At its commencement it lies in front of the superior laryngeal nerve, and the longus colli and rectus capitis anticus major muscles. On its outer side we find the internal carotid artery, internal jugular vein and pneumogastric nerve. On its inner side we find the superior cornu of the thyroid cartilage, the posterior margin of the thyro-hyoid ligament, the great cornu of os-hyoides, the side of the pharynx, the submaxillary gland, angle of the jaw, and still more internally the tonsil. After it has entered into the substance of the parotid, it is covered by the skin, the platysma, the cervical fascia, a portion of the gland, by its 69 BRANCHES OF THE EXTERNAL CAROTID. corresponding vein, namely the temporo-maxillary, and by the facial nerve. Its deep surface is here separated from the internal carotid by the stylo-glossus and stylo-pharyngeus muscles, the styloid process, or when this process is short, by the stylo-hyoid ligament, the glosso-pharyngeal nerve, and occasionally the pharyngeal branch of the pneumogastric nerve, and part of the gland. Operation of tying the External Carotid. —The external carotid may be tied either above or below the crossing of the posterior belly of the digastric muscle. For the latter purpose an incision should be made through the integuments and platysma myoides, from beneath the angle of the jaw to the side of the thyroid cartilage. This incision will expose the digastric muscle, and by drawing it a little upwards, the artery may be exposed and secured beneath the origin of its superior thyroid branch. Care should be taken not to include the superior laryngeal nerve which descends obliquely inwards behind the origin of the external carotid. Mr. Guthrie is of opinion, that the ligature should be applied near its origin, that is, immediately below where the superior thyroid artery is given off. In opening abscesses of the tonsil it should be borne in mind, that the convexity of the external carotid may be closely applied to the outside of the swollen gland. The branches of the external carotid artery are nine in number, and may be included under the following heads : Anterior. Superior Thyroid. Lingual. Facial or Labial. Posterior. Occipital. Posterior Auricular. Internal, or Ascending. Pharyngea Ascendens, External. Transversalis Faciei. Terminating. Superficial Temporal. Internal Maxillary. 70 SUPERIOR THYROID ARTERY. The Superior Thyroid Artery arises opposite the thyro-hyoid space. It first ascends towards the os-hyoides, and then descends on the side of the larynx on a plane anterior and internal to the external carotid, to terminate in the thyroid gland. In this course it describes a curvature, the convexity of which looks upwards, touches the os-hyoides, and corresponds to concavity of a similar curvature in the lingual artery. Posteriorly it rests on some areolar tissue and the superior laryngeal nerve : anteriorly it is covered by the integuments, platysma myoides, cervical fascia, and by some small veins passing outwards from the larynx to the internal jugular vein; also by the sterno-hyoid, sterno-thyroid, and omohyoid muscles, and an internal branch of the descendens noni nerve which supplies the latter muscle. The superior thyroid artery gives off the following branches :— Hyoidean. Superior Laryngeal. Sterno Mastoid. Inferior Laryngeal or Crico- Thyroid. Terminating. The Hyoidean branch, which is small, passes inwards beneath the thyro-hyoid muscle, supplies the areolar tissue in this situation, and anastomoses with the corresponding branch of the opposite side. The Superior laryngeal brunch descends with the superior laryngeal nerve, passes beneath the thyro-hyoid muscle, and pierces the ligament of the same name. Here it divides into two branches, —one of which ascends behind the os-hyoides to supply the anterior surface of the epiglottis and mucous membrane: the other descends on the inside of the ala of the thyroid cartilage, and terminates in the crico-arytenoid, and crico-thyroid muscle, and by a great number of small branches in the mucous membrane of the larynx. 71 BRANCHES OF THE SUPERIOR THYROID. The Sterno-mastoid branch is constant, but variable in size : it crosses in front of the sheath of the carotid artery to reach the deep surface of the sterno-mastoid muscle, in which it is lost. This artery frequently arises from the posterior part of the external carotid, close to the origin of the lingual; from this point it first runs upwards, hooks over the lingual nerve, which it draws into an angle salient downwards; and then running downwards and outwards it reaches the deep seated surface of the sternomastoid. The Inferior laryngeal or crico-thyroid branch may come directly from the superior thyroid, but more usually it arises from its internal terminating branch. It passes horizontally inwards in front of the crico-thyroid membrane, and along the inferior margin of the thyroid cartilage, to anastomose with its fellow of the opposite side and supply the crico-thyroid membrane. This artery is pretty constant, though it varies as to size and origin. If it be absent at one side, the artery of the opposite side will be found larger than usual. It is often a branch of the superior laryngeal. When the superior thyroid artery arrives near the thyroid gland it divides into four terminating or proper thyroid branches, namely, the internal, external, anterior, and posterior. The internal terminating branch descends along the internal margin of the corresponding lobe, and unites in forming an arch with the corresponding branch of the opposite side : this branch usually gives off the inferior laryngeal artery. The external terminating branch descends along the external margin of the corresponding lobe and anastomoses with the inferior thyroid. The anterior terminating branch is distributed to the anterior surface of the upper portion of the gland : it is not always present. Lastly, the posterior terminating branch descends be- 72 LINGUAL ARTERY. tween the front of the trachea and the thyroid gland, in the substance of which gland it is lost. The superior thyroid artery lies on a plane anterior and internal to the common carotid; and, therefore, in attempts at suicide, it is the vessel usually divided. In this case, we may either secure the bleeding vessel, or put a ligature on the external carotid beneath the origin of the former. This artery has been tied for the purpose of reducing the size of a bronchocele, or preparatory to extirpating the thyroid gland. The incision that exposed the external carotid will also expose the origin of the superior thyroid. In a case related in Houston's Catalogue (p. 80), this vessel crossed the crico-thyroid membrane. The Lingual Artery is the next in order, but as the branches of the facial or labial are more superficial, the student will find it expedient to dissect these first, and afterwards examine the course and branches of the lingual. This latter vessel arises a little above the superior thyroid, and nearly opposite the os-hyoides : it may be divided into three stages : in the first, it extends from its origin to the outer edge of the hyo-glossus muscle ; in the second, it passes behind (or more correctly speaking, deeper than) the muscle ; in the third stage it gets the name of the ranine artery, and extends from the internal margin of the hyo-glossus muscle to its termination. In the first stage it ascends a little, and then turns inwards, to get above the great cornu of the os-hyoides, making a curvature, the convexity of which looks upwards, while the concavity, looking downwards, corresponds to the convexity of the superior thyroid artery, from which it is separated by the extremity of the great cornu of the oshyoides. In this stage it corresponds posteriorly to some loose areolar tissue, to the superior laryngeal nerve, and to a small portion of the middle constrictor of the pharynx at its attachment to the great cornu of the os-hyoides: ante- 73 BRANCHES OF THE LINGUAL. riorly it is covered by the integuments, platysma myoides, cervical fascia, lymphatic glands, and some small veins. The lingual nerve lies superficial and superior to the artery, and sometimes when the nerve descends a little lower down than usual, it touches the artery : corresponding to the first stage of the course of the Lingual artery, the tendon of the digastric may be seen lying superior to the lingual nerve; so that from above downwards in this situa- Fig. 9.— Dissection of the Lingual Artery. 1, Frontal Bone. 2, Crista Galll of the Ethmoid bono. 3, Sphenoid Bone. 4, Sphenoidal Sinus. 5, 5. Vertical section of the Nose. 6, Septum of Nose, with arterial anastomoses. 7, Twig from one of the terminating branches of the Sphenopalatine Artery, descending through the Canal, O. 8. Upper Lip. 9, Soft l'alate or Velum Pendulum Palati. 10, 10, Branches of' the Superior Palatine Artery which descend through the Posterior Palatine Canal. 11, Lower Lip. 12, The Tongue. 13, Lower Jaw. 14, Genio-hyo-glossus Muscle. 15, Hyo-glossus Muscle. 16, Stylo-glossus Muscle. 17, Genio-hyoid Muscle. 18, Mylo-hyoideus cut and reflected. 19, Portion of Sterno-hyoid Muscle. 20, Part of the Omo-hyoid Muscle. 21, Thyroid Cartilage. 22, Thyro-hyoid Muscle. 23, Po> tion of Inferior Constrictor of the Pharynx. A, Common Carotid Artery. B, K, External Carotid Artery. C, Internal Carotid, a, Supeiior Thyroid Artery cut. b, Superior Laryngeal Branch of Thyroid, c, Lingual Artery d, Dorsalis Lingua), e, Hyoidean branch of Lingual Artery, f, Sublingual Arteiy. g, Ranine Arteiy ascending to the base of the Tongue, h, Continuation of Ranine Artery, i. Facial or External Maxillary Artery. m. Branch of Spheno-palatine Artery. n, Branch of Anterior Ethmoidal Artery, o, Incisive Canal. 74 BRANCHES OF THE LINGUAL. tion we find, first the tendon, secondly the nerve, and lastly the artery. In the second stage the artery passes upwards and inwards, and frequently pierces the posterior fibres of the hyo-glossus muscle in order to get to its deep seated surface, along which it then passes : the hyo-glossus thus separates the Lingual artery from the lingual nerve, which latter lies upon the cutaneous surface of the muscle. In this second stage the artery at first frequently lies superficial to a few of the posterior fibres of the hyo-glossus muscle; these fibres have received the name of ceratoglossus muscle: afterwards when it gets to the deep seated surface of the hyo-glossus, it runs along the external surface of the middle constrictor of the pharynx at its origin from the great cornu of the os hyoides: this portion of the bone lies immediately below the artery, and the vessel itself still lies below the level of the nerve. In this situation the artery sends minute branches to the middle constrictor. In the third stage, where it is sometimes called the ranine artery, it ascends a little to reach the base of the tongue, and then proceeds horizontally along the inferior surface of this organ between the genio-glossus and lingualis muscles, and above the frsenum linguae: here it terminates in anastomosing with the artery of the opposite side. In this third stage it is accompanied by the ninth nerve, which at the anterior edge of the hyo-glossus muscle turns under, that is, superficial to the artery, and then proceeds along its inner side, towards the tip of the tongue; so that in this situation the two lingual nerves lie between the two arteries. The branches given off by the lingual artery are three in number : The Hyoidean, Dorsalis Linguae and Sublingual. The Hyoidean branch usually arises at the outer edge of the hyo-glossus muscle : it supplies the epiglottidean 75 LIGATURE OF THE LINGUAL ARTERY. gland, and the muscles attached to the os-hyoides, and anastomoses with the corresponding branch of the opposite side and with the superior thyroid artery. The Dorsalis lingua,, may be traced running upwards and outwards, under cover of the hyo-glossus muscle, towards the base of the tongue ; some of its branches are lost in the stylo-glossus muscle and base of the tongue ; while others ascending, supply the tonsil and velum palati. It lies immediately under the mucous membrane. In many cases this artery is deficient or diminutive, and sometimes its place is supplied by two or three very small branches. The Sublingual artery proceeds forwards and outwards to supply the gland of the same name : it also sends branches to the mucous membrane of the mouth, and often one that pierces the mylo-hyoid muscle to arrive at the anterior belly of the digastric. It anastomoses with that of the opposite side and with the submental artery. Sometimes the place of this artery is supplied by a large branch from the submental, which pierces the mylo-hyoid muscle to arrive at the gland. Accompanying Veins. The lingual artery is accompanied in its first and second stages by one or two vence comites, which arise from a plexus at the base of the tongue, and terminate in the internal jugular vein. From the same plexus arises a satellite vein of the lingual nerve, which accompanies the hypo-glossal or ninth nerve, and opens into the facial, or into the pharyngeal vein: lastly, the ranine vein lies on the inferior surface of the tongue, superficial and external to the artery in its third stage, and then passes between the mylo-hyoid and hyo-glossns muscles to terminate in the facial vein. Operation of tying the Lingual Artery. This operation has been proposed by Beclard for hemorrhage after extirpation of portion of the tongue, or from other causes. The lingual artery may be exposed by an incision extending tranversely from the os-hyoides to the margin of the sterno-mastoid muscle. The skin, platysma and fascia 76 FACIAL ARTERY. being divided, the glistening tendon of the digastric muscle is brought into view: beneath this, and lower down, is the hypo-glossal nerve, much duller in its appearance than the tendon; whilst the artery will be found situated still lower and a little deeper than the nerve. Mr. Guthrie advises that the trunk of the external carotid should be tied whenever there is unmanageable hemorrhage from its branches. The ranine artery may be wounded in the operation of dividing the frsenum linguae. This will not occur if blunt pointed scissors be used, and their points directed downwards during the operation. When the artery is wounded in the child, the hemorrhage is favoured by the vacuum produced in sucking, and by the heat and mobility of the parts. As the ranine arteries anastomose at their extremities only, the right and left sides of the tongue may be filled with different coloured injections. It has been proposed by Velpeau to puncture the ranine veins in cases of glossitis. The Facial Artery, called also the labial or external maxillary, arises immediately above the lingual, and often together with it by a common trunk. The artery may be divided into two stages—a cervical and a facial stage; in its cervical stage it ascends, lying near the outer surface of the mylo-hyoid and hyo-glossus muscles and under cover of the skin and superficial fascia, platysma-myoides, cervical fascia, digastric and stylo-hyoid muscles, the lingual nerve, and portion of the sub-maxillary gland, into the substance of which it penetrates : in this situation it lies under cover also of the body of the inferior maxillary bone, and after passing through the gland, touches the internal pterygoid muscle: it here makes a turn, the convexity of which is directed upwards and lies anterior and external to the tonsil: from this point it descends, reaches the inferior margin of the body of the bone and curves underneath its cutaneous surface where the first stage terminates. In its facial stage it ascends tortuously from Fig. 10.— Dissection of some of the terminating branches of the External Carotid Artery and part of the course of the Subclavian Artery. A, Right Subclavian Artery in third stage. B, Internal Carotid Artery. C, External Carotid Artery. K. Temporal Artery dividing lower down than usual, a, Supra-scapular Artery crossiug Anterior Scalenus Muscle, b, Irregular Posterior Scapular Artery coming from Subclavian, and in this case passing between branches of Brachial Plexus, c, Muscular Artery, e, Superior Thyroid Artery, f. Facial Artery, g. Branch of Transverse Artery of face, h. Branch of Posterior Auris Artery, i. Branch of Occipital Artery. 1, Anterior branch of Temporal Artery, m, Posterior branch of Temporal Artery, n. Frontal Artery. 1, 1, Pinna. 2, 2, Temporal Muscle covered by Temporal Aponeurosis. 3, Orbicularis Palpebrarum. 4, Angular Artery. 5. Levator Labii Superioris. 6, Levator Anguli Oris, or Musculus Caninus. Zygomatics Minor. 8, Zygomatieus Major. 9, Orbicularis Oris. 10, Muscular branches of Mental Artery. 11, Depressor Anguli Oris, or Triangularis Oris. 12, Buccinator Muscle. 13, Parotid Gland 14, Masseter Muscle. 15, Sterno-mastoid Muscle. 16, Muscular branch of Occipital Artery. 17, Submaxillary Gland. 18, Levator Anguli Scapula) Muscle. 19, Middle and Posterior Scaleni Muscles. 20, Anterior belly of Omo-hyoid Muscle. 21, Sterno-thyroid Muscle. 22, Sterno-hvoid Muscle. 23, Thyroid Cartilage, 24, Trapezius Muscle. 25, Posterior belly of Omo-hyoid Muscle. 26, 26, 2fi, Brachial Plexus. 27, Anti-rior Scalenus Muscle. 28, 29, Origins of Sterno-mastoid Muscle. 30, Trachea, 31, Ueltold. 32, Pectoralis Major. 78 BRANCHES OF THE FACIAL. the inferior margin of the body of the inferior maxilla, along the side of the face, till it arives at the internal angle of the eye, where it terminates in anastomosing with the nasal and frontal branches of the ophthalmic artery. In this stage it lies on the inferior maxillary bone, in a groove frequently provided for its reception, between the masseter muscle posteriorly, and the triangularis oris anteriorly: it next lies on the buccinator muscle, the levator anguli oris or musculus caninus, the levator labii superioris proprius ; and, lastly on the nasal division of the levator labii superioris alseque nasi. In this stage it is covered by the skin and superficial fascia, platysma, and frequently by a few of the posterior fibres of the triangularis oris muscle ; by the zygomatieus major and minor, by the labial division of the levator labii superioris alseque nasi near its insertion, and finally by a few of the internal and inferior fibres of the orbicularis palpebrarum muscle. In this situation the artery may be seen, after it has escaped from under cover of the labial portion of the levator labii superioris alseque nasi, lying against the outer side of the nasal portion of this muscle and thus separating the two portions from each other. The Facial Vein is much less tortuous than the artery, and at the root of the nose and inner angle of the eyelids it communicates with the ophthalmic and with a large vein that descends on the middle line of the forehead, and communicates with its fellow of the opposite side by means of a short branch which passes across the root of the nose : as the facial vein descends, it crosses the cutaneous surface of the parotid duct, being external to the artery. On the body of the inferior maxillary bone, it lies close to the artery, touching its outer surface : it then descends superficial to the submaxillary gland, and either terminates in the external, internal, or anterior jugular vein. The facial artery usually gives off eleven branches— five in its cervical, and six in its facial stage. 79 BRANCHES OF THE FACIAL. Branches of Cervical stage. Branches of the Facial Stage. Inferior Palatine. Tonsilitic. Submaxillary. Inferior or Submental. Internal Pterygoid. Buccal. Inferior Labial. Inferior Coronary. Superior Coronary. Dorsalis Nasi. Angular. The Inferior Palatine branch, is usually small: it penetrates between the stylo-glossus and stylo-pharyngeus muscles to arrive at the superior and lateral part of the pharynx, where it divides into two principal branches which are distributed to the pharynx, tonsils, and Eustachian tube. The Tonsilitic artery sometimes comes off directly from the facial, and passes between the internal pterygoid and stylo-glossus muscles to its destination. The Submaxillary. As the facial artery is passing through the substance of the submaxillary gland it gives off several small branches, which are distributed to this structure and also to the tongue and mucous membrane of the mouth. The Inferior mental, or submental branch, is a larger artery than the preceding ; it runs along the base of the inferior maxillary bone towards the symphisis menti, being covered by the platysma myoides, and lying upon the cutaneous surface of the mylo-hyoid muscle. Near the middle line it divides into two branches, one of which crosses in front of the anterior belly of the digastric muscle to anastomose with that of the opposite side, while the other ascends on the front of the chin to supply the integuments, and communicates with the inferior dental branch of the internal maxillary artery. In some cases the inferior mental gives off the sublingual artery which more usually arises from the lingual. The Internal Pterygoid branch. On reaching the anterior margin of the internal pterygoid muscle the facial artery 80 BRANCHES OF THE FACIAL. gives off a small branch which is distributed to the substance of this muscle. The artery in its facial stage usually gives off the six branches already enumerated : these may be divided into external, internal, and terminating. The buccal and some small muscular branches constitute the external; the inferior labial, the two coronaries, and the dorsalis nasi compose the internal, and the angular is the terminating artery. The Buccal branch runs backwards from the outer part of the facial over the buccinator muscle, and then getting on the inside of the ramus of the lower jaw, terminates by anastomosing with the internal maxillary. Its branches are distributed to the buccinator and masseter muscles, to the fat of the cheek, the parotid gland and Steno's duct. The Inferior labial branch is distributed to the muscles and integuments of the lower lip, and anastomoses with the submental and dental arteries. The Inferior coronary artery passes inwards in a very tortuous manner beneath the triangularis oris, and quadratus menti, and proceeds along the margin of the lower lip, close to its mucous membrane, where it anastomoses with the artery of the opposite side. In its course it supplies the above mentioned muscles, and anastomoses with the inferior labial, submental aad dental arteries. The Superior coronary artery arises near the commissure of the lips, and runs tortuously inwards between the labial glands and mucous membrane of the upper lip. On the middle line it anastomoses with the artery of the opposite side, and sends upwards, towards the septum of the nose, a small branch termed the artery of thefiltrum, the branches of which are distributed to the muscles, integuments, and mucous membrane of the upper lip and to the gums, where these small vessels anastomose with branches of the inferior dental artery. The Dorsalis, or lateralis nasi artery, ascends obliquely G Fig 11.— Dissection of the anastomoses between the Facial, Transverse Facial branches of the Internal Maxillary, Ophthalmic and Temporal Arteries. ih f™?'* 1 . Portion of Oooipito-frontalis Muscle. 2, 2, Orbicularis Palpebrarum. 3,4, 7 7vl r Jr„ &u P erloris Alseque Nasi. 5. Levator Anguli Oris. 6, Zygomatieus Minor. Mncni f^ 10 ,^ 8 Ma ' or - 8l Faioti< i Gland. 9. Masseter. 10, Small Artery to Buccinator Oil. ii I'.? epre ,? s ? r A i-SuHOris. 12, 12, Quadratus Menti of each side, 13, Orbicularis K a*=„ j- of t he Flltrum coming off from the junction of the Superior Coronaries. rv, Ascending branch of Submental Artery. P, P, P, P, Palpebral, a, Frontal Artery. thJ TflS °i , r f n of rem P° ral Artery, the upper branch anastomosing with a branch of Art™ 7 A J t ? ry- „ d ' transversalis Faciei Artery, e, e, Facial or External Maxillary A*™' • \ wlg t0 Ma8seter Muscle, g, Inferior Coronary Arteiy. h, Superior Coronary 1 Inf • -'Anastomosis between the Nasal branch of the Ophthalmic and Angular Arteries. Ori,i;„V°A r -r aDlal Arte-T- m, Facial Artery giving off Superior Coronary Artery, n, Infra urmtal Artery, o, Portion of Corrugator Supercilii Muscle. 82 BRANCHES OP THE FACIAL. inwards, and lies on the outer surface of the nasal portion of the levator labii superioris absque nasi muscle, and distributes its branches to the muscles, cartilages, and integuments of the nose; after which it anastomoses with the artery of the opposite side. Some of its minute branches pierce the fibro cartilages to reach the mucous membrane. We often find the place of this artery supplied by a number of small branches ; or on the contrary, there may be a very considerable single branch, in which case the angular or terminating branch is particularly small. The Angular artery is the terminating branch of the facial : it ascends between the two portions of the levator labii superioris alseque nasi, and anastomoses with the nasal or terminating branch of the ophthalmic artery. When it becomes necessary to make an incision into the lachrymal sac, it should be made external to the angular artery The facial artery can be readily compressed or tied, as it is passing over the body of the inferior maxillary bone. At its origin this vessel is covered by a few lymphatic glands, some of which accompany it on the face : these may enlarge and displace the submaxillary gland so as to occupy its natural postion. A tumor of this kind may be removed without dividing the trunk of the facial artery; and such has probably been the nature of the tumor in many of those operations that have been termed extirpation of the submaxillary gland. Mr. Colles doubts the possibility of removing it, on account of its connexion with the facial artery, and its dipping behind the mylo-hyoid muscle; but a still greater difficulty arises from its vicinity to the lingual nerve, and its intimate connexion with the gustatory nerve. In certain amputations of a portion of the lower jaw, the artery "is necessariUy cut across, and care should be taken to divide it on the bone, and not beneath it, lest it should retract too deeply into the submaxillary space. Its coronary branches are divided in the operation for hare lip ; it is not necessary to tie them, but the suture 83 OCCIPITAL ARTERY. needle must be passed sufficiently deep, and near the mucous membrane, in order to close the posterior part of the wound, as otherwise there might be serious hemorrhage into the mouth. No artery presents greater varieties either as to origin, termination, size, or relations, than the facial; it sometimes arises in company with the lingual; in many cases it terminates by its coronary branches, and in others by the dorsalis nasi; in these cases the branches of the facial are replaced by those of the transversalis faciei : on the other hand, according to Soemmering, it may extend to the forehead, giving off the palpebral and lachrymal arteries. On one side there may be a large facial artery, and a mere radimentary artery on the other. The facial artery communicates with the internal maxillary by the infra-orbital and inferior dental branches of the latter, and with the internal carotid by its inosculation with the nasal branch of the ophthalmic. The Occipital Artery arises from the posterior part of the external carotid, nearly opposite to the origin of the lingual artery : it may be divided into three stages. In its first stage it lies in the anterior superior lateral triangle of the neck, running towards the digastric groove of the temporal bone, and extends as far as the anterior margin of the sterno-mastoid muscle, passing obliquely over the concavity of the arch formed in the neck by the hypo-glossal nerve, which is therefore said to pass round it. In this stage the occipital artery at first runs along the inferior margin of the posterior belly of the digastric muscle ; more posteriorly however, this muscle partly covers the artery, and forms one of its superficial relations; still more superficially we find a portion of the parotid gland, the fascia of the neck, a few fibres of tflie platysma, and the integuments. Its deep seated relations are the internal carotid artery, the pneumogastric nerve, and the internal jugular vein, from which last it is separated by the spinal accessary nerve. g 2 84 BRANCHES OF THE OCCIPITAL. In its second stage it passes somewhat horizontally from before backwards, and in its course is covered by the following parts ; —the skin and a strong layer of condensed areolar tissue, the sterno-mastoid muscle, and behind this by the splenius capitis; then deeper, by the trachelo-mastoideus or complexus minor, then by the mastoid process itself, and still deeper by the origin of the posterior belly of the digastric muscle. In this stage the artery is lodged in a distinct, but frequently superficial groove in the temporal bone, internal to the deep groove for the posterior belly of the digastric, and lies on, or more correctly speaking, external to the outer margin of the rectus capitis lateralis muscle, and above the transverse process of the atlas ; it then passes across the insertion of the obliquus superior, and afterwards arches over the insertion of the complexus major muscle : it occasionally lies underneath this muscle. In its third stage it arrives at the posterior region of the neck by passing through a condensed fascia, which unites the posterior margin of the sterno-mastoid muscle with the anterior border of the trapezius at their insertions, and then ascends obliquely inwards and ramifies on the occipital region of the head. In this stage it appears in the triangular space which the splenii capitis muscles form by their divergence on the middle line in the superior part of the back of the neck, and then ascends on the back of the head, through the fibres of the occipital muscle, in company with the posterior branch of the second cervical nerve. The occipital artery gives off the following branches Muscular. Posterior Meningeal. Descending Cervical. Mastoidean. Terminating. The Muscular branches are distributed to the posterior belly of the digastric muscle, and to the stylo-hyoid and sterno-mastoid muscles. It occasionally gives off the stylo-mastoid artery, which enters the stylo-mastoid fora- 85 BRANCHES OF THE OCCIPITAL. men and anastomoses with a branch of the middle meningeal from the internal maxillary. The Posterior Meningeal branch arises from the occipital as it lies on the side of the internal jugular vein, it enters the foramen lacerum posterius, and is distributed to the dura mater in the posterior and lateral regions of the interior of the cranium. The Descending Cervical branch arises from the artery as it lies under cover of the splenius, near its posterior margin : it sends branches to the muscles in the immediate neighbourhood, and anastomoses with the cervicalis superficialis and cervicalis profunda arteries. There are sometimes two or even three descending cervical branches present. The Mastoidean branch, at its origin, corresponds to the posterior surface of the mastoid process of the temporal bone ; it passes through the mastoidean foramen in this part of the bone, accompanied by a vein, sends minute branches to the mastoid cells, and is distributed within the cranium to the dura mater of the occipital fossse. As the occipital artery is arching over the obliquus superior muscle it communicates with the vertebral artery ; sometimes it gives off the stylo-mastoid artery. The Terminating branches of the occipital artery ascend tortuously in the course of the lambdoidal suture to supply the occipito-frontalis muscle and integuments, and to anastomose with the temporal and posterior auricular arteries, and with the occipital of the opposite side. We sometimes find one of those small branches passing through the parietal foramen to be lost in the dura mater. Should it ever be nescessary to tie the occipital artery in case of profuse hemorrhage from any of its branches, the incision already recommended for exposing the external carotid will also expose this vessel in the commencement of its first stage; or an incision may be made along the lower margin of the posterior belly of the digastric muscle, on raising which the artery is brought into view. 86 POSTERIOR AURICULAR ARTERY. Care should be taken not to injure or include the hypoglossal nerve. The depth of this artery behind the mastoid process is very variable, and unless there be a wound to guide us to the vessel, it is not an operation that should be attempted. The Posterior Auricular Artery is one of the smallest branches of the external carotid : it arises in the substance of the parotid gland, nearly opposite the apex of the styloid process, and ascends along the superior margin of the posterior belly of the digastric muscle, till it arrives at the interval between the external auditory canal and mastoid process, where it divides into its two terminating branches, an anterior and posterior aural. The posterior auricular artery gives off the following branches; — Stylo-mastoid. Anterior, and Posterior Aural. The Stylo-mastoid branch enters the stylo-mastoid foramen, and after supplying the aqueduct of Fallopius, the tympanum and semicircular canals, it terminates by anastomosing with a branch of the middle meningeal artery which enters by the hiatus Fallopii. The Anterior aural branch is distributed to the internal or deep surface of the pinna. The Posterior aural branch ascends between the retrahens auris muscle and bone, and supplies the integuments covering the mastoid process, and the temporal and retrahens auris muscles. Before its bifurcation the posterior auricular sends branches to the parietes of the external auditory canal, to the parotid gland, and to the digastric and stylo-hyoid muscles. In the operation of cutting down on the facial nerve, in order to remove a portion of it after its exit from the stylo-mastoid foramen, the trunk of this artery must have been usually divided, together with its stylo-mastoid branch. 87 PHARYNGEA ASCENDENS ARTERY. Mr. Harrison saw a case in which it was tied in front of the mastoid process, for aneurism by anastomosis on the external surface of the pinna—but without success. The Pharyngea Ascendens Artery may be exposed by the dissection recommended for exposing the internal carotid, and therefore the student would find it more expedient to defer its examination for the present ; he may however study its relations in the neck. The pharyngea ascendens is the first and smallest branch of the external carotid. After its origin it ascends in the neck, being related, — posteriorly to the spinal column, the rectus anticus muscle, and the superior laryngeal nerve; — anteriorly to the stylo-pharyngeus muscle, — internally to the pharynx, and externally to the superior cervical ganglion of the sympathetic nerve. In this course it gives off a few irregular branches to the muscles of the pharynx, and terminates by dividing into two branches, the pharyngeal and meningeal. The Pharyngeal branch passes obliquely upwards and inwards, and sends off a number of twigs, some of which ascend through the superior constrictor of the pharynx, while others descend in the substance of the middle and inferior constrictors : they anastomose with branches of the superior thyroid and lingual arteries. The Meningeal branch ascends between the carotid artery and jugular vein, ands upplies these vessels, the pneumogastric nerve, the Eustachian tube, the rectus capitis anticus, and longus colli muscles. It then passes through the foramen lacerum posterius to ramify on the dura mater, having previously sent a small branch into the cranium through the cartilaginous substance that fills the foramen lacerum anterius. This artery is not very liable to accident, on account of its deep situation. Scarpa, however, relates a case in which it was ruptured. The Transversalis Faciei Artery usually arises from the outer part of the external carotid a little before its 88 TEMPORAL artery. termination. At its origin it is imbedded in the parotid gland, through which it proceeds outwards towards the integuments, then turns round the ramus of the lower jaw, and ascends slightly on the cutaneous surface of the masseter muscle. In this situation it lies above the duct of the parotid gland, concealed by the socia parotidis and surrounded by the filaments of the facial nerve. This artery sends a twig to the masseter muscle, which anastomoses with a branch of the internal maxillary ; farther on, it sends several twigs to the parotid gland and its duct, and after supplying the zygomatic muscles, the orbicularis palpebrarum and the integuments, it terminates by anastomosing with the infra-orbital, buccal and facial arteries. The Superficial Temporal Artery arises immediately behind the neck of the inferior maxillary bone, and ascends through the parotid gland in front of the external auditory canal. It next passes between the attrahens auris muscle and the horizontal ramus of the zygoma, and ascends into the temporal region, accompanied by the superficial temporal twig of the inferior maxillary division of the fifth nerve : here it lies on the temporal aponeurosis, and is covered by a fascia of considerable strength, which is continuous with the cervical aponeurosis covering the parotid gland. In the middle of the temporal region the artery terminates by dividing into two branches. The temporal artery gives off the following branches : Glandular. Masseteric. Articular. Anterior Auricular. Middle Deep Temporal. Anterior Temporal. Posterior Temporal. The Glandular branches are small twigs which come off from the artery, and are distributed to the structure of the parotid gland. The Masseteric branch is a small twig which passes 89 BRANCHES OF THE TEMPORAL. forwards from the artery to supply the masseter muscle : there may be two or even more of these twigs. The Articular branch, also passes forwards and supplies the structures entering into the formation of the temporomaxillary articulation : this branch is also called the capsular artery. The Anterior auricular branch passes backwards to supply the pavilion and auditory canal, it anastomoses with branches of the posterior auris. The Middle deep temporal artery arises immediately above the zygoma, pierces the temporal aponeurosis, and divides into several branches which ramify in the temporal muscle, and communicate with the other temporal arteries. The Anterior temporal branch ascends tortuously towards the forehead, supplies the integuments, orbicularis palpebrarum and muscles of the forehead, and anastomoses with the corresponding artery of the opposite side, and with the frontal and supra-orbital arteries. This is the branch selected for arteriotomy. The Posterior temporal branch ramifies on the side of the head, and anastomoses with the artery of the opposite side, and with the occipital and posterior auris arteries. The temporal artery is not subject to much variety : it may, however, arise nearer the angle of the inferior maxillary bone than we have above described, in which case it usually gives off the transversalis faciei. This vessel should never be opened near the zygoma, as unmanageable hemorrhage or inflammation and abscesses may be the consequence. Mr. Harrison mentions a case in which this practice was followed by a varicose aneurism. The anterior branch should be selected for arteriotomy ; and should a small aneurism be the result, as occasionally happens, it may be cured by compression, or by making an incision through the tumor, turning out the coagulum, and dressing it from the bottom. Mr. Liston advises to divide the artery at each side of the tumor, and tie the bleeding extremities. 90 INTERNAL MAXILLARY ARTERY. The Internal Maxillary Artery may be exposed in the following manner : having removed the brain and uncovered the masseter muscle, we may carry a very small and pointed saw upwards behind the posterior extremity of the zygoma, and divide it from within outwards as near its roots as possible. We next remove the roof and contents of the orbit in the usual manner, and sink the point of the saw into the anterior extremity of the sphenomaxillary fissure, and from this point make two incisions; one upwards and outwards through the outer wall of the orbit to terminate at the external angular process of the frontal bone : the other downwards and inwards, through the floor of the orbit to terminate on the outside of the supra-orbital foramen. These two incisions will include the greater part of the malar bone, and the zygoma will fall down, carrying with it the masseter muscle. Our next object is to detach the temporal muscle and vessels from the temporal fossa, and allow them to hang down from the coronoid process of the inferior maxillary bone. We then introduce a knife into the temporo-maxillary articulation above the fibro-cartilage, and divide the portion of the capsular ligament, which connects the latter to the circumference of the glenoid cavity. Lastly, we make two incisions, meeting internally at an angle, so as to include the greater part of the squamous plate of the temporal bone, and the great wing of the sphenoid bone ; one of these incisions may commence immediately in front of the ear, and be continued vertically down through the side and base of the skull till it terminates immediately behind and external to the spinous process of the sphenoid bone ; the second may be made with a small saw, and as the malar bone is already removed, the incision may be readily made to connect the inferior angle of the sphenoidal fissure, with the internal extremity of the preceding incision : on the inside of the latter, the foramen ovale and foramen rotundum should lie unopened. A slight stroke of the hammer against the bone between 91 INTERNAL maxillary artery. these two incisions will detach it, and give a full view into the zygomatic fossa: the branches of the artery may then be dissected. The vidian and posterior palatine canals can be readily broken into, if a vertical section of the skull be previously made through the adjacent nostril. The artery may be very readily exposed by another method: —after the transversalis faciei artery, together with the masseter muscle and its superficial relations, have been examined and removed, a horizontal section may be made through the ramus of the inferior maxilla immediately above its angle with a fine metacarpal saw; care being taken that none of the soft parts under cover of the bone shall be injured : another horizontal section may now be made through the neck of the jaw, immediately below the condyle, and the coronoid process removed from its connexion with the temporal muscle. The piece of bone included between the two incisions may also be removed, and afterwards can be replaced at pleasure. The zygomatic arch should be next taken away, and this may be done by two incisions, —one made posteriorly through this process of bone, close to its origin,—the other anteriorly, close to the external part of the orbit through the zygomatic process of the malar bone. The internal maxillary artery is larger than the temporal, and together with it is contained for a very short distance within the parotid gland. It may be divided into four stages; the first stage extends from its origin to the inter-pterygoid space : its second corresponds to this space : its third extends from this space to the upper part of the pterygo-maxillary fossa, and the fourth is the termination of the artery in this fossa. In its first stage it runs horizontally forwards and lies on the inside of the lower portion of the neck of the inferior maxillary bone, which it separates from the internal lateral ligament of the temporo-maxillary articulation : the bone is frequently grooved in this situation for the reception of the artery. In its second stage we find it passing forwards and in- 92 BRANCHES OF THE INTERNAL MAXILLARY. wards, forming a curvature the concavity of which looks upwards and embraces the external pterygoid muscle : in this part of its course it lies in a triangular space, bounded by the external pterygoid muscle above, the internal pterygoid beneath, and the ramus of the lower jaw externally. In the same triangular space we observe the gustatory and inferior dental nerves, descending to their destination, but as the artery lies close to the neck of the inferior maxilla, it is situated external to these nerves. In the third stage we find the artery running upwards and inwards towards the root of the pterygoid process, after passing between the outer surface of the external pterygoid muscle, and the fibres of the temporal muscle. In this situation the artery is related to the buccal nerve; at first the artery is posterior to the trunk of the nerve, and afterwards lies upon a plane external to it. Finally it sinks between the two origins of the external pterygoid muscle, and terminates in the pterygo-maxillary fossa lying to the outside of Meckel's ganglion, and the spheno-palatine foramen: this constitutes its fourth stage. In some (not very rare) cases the artery passes to its destination, not through the inter-pterygoid space as above described, but between the external pterygoid muscle and the base of the skull. We shall now examine its branches in the order in which they arise. The internal maxillary artery gives off the following branches :— Middle Meningeal. Tympanic. Inferior Dental. Meningea Parva. Posterior deep Temporal. Masseteric. Pterygoid. Buccal. Anterior deep Temporal. Posterior Superior Dental. Infra Orbital. Vidian. Superior Palatine. Spheno-Palatine. The Middle meningeal artery is the largest branch of the internal maxillary. It arises on the inside of the BRANCHES OF THE INTERNAL MAXILLARY. 93 neck of the lower jaw, and ascends obliquely inwards to the base of the skull, behind the external pterygoid muscle, which consequently separates it from the continued trunk of the internal maxillary artery. In this part of its course it usually passes between the roots of the temporo-auricular nerve, lies posterior to the otic ganglion and then enters the spinous foramen in the base of the skull, after passing between the origin of the circumflexus palati muscle in front, and the internal lateral ligament of the lower jaw posteriorly. In this part of its course, it supplies the pterygoid muscles, the muscles of the pharynx, and the temporal and sphenoid bones. Having passed within the skull, the middle meningeal artery ascends beneath the dura-mater into the middle fossa of the cranium, and terminates by dividing into an anterior and posterior terminating branch. Before its division it sends a branch through the sphenofrontal fissure to terminate in the lachrymal gland; another through the hiatus Fallopii, which supplies the facial nerve and anastomoses with the stylo-mastoid artery; and a third through the canal for the internal muscle of the malleus, to be distributed on the lining membrane of the tympanum. The anterior terminating branch, much larger than the posterior, ascends through the groove in the great wing of the sphenoid bone, and the anterior inferior angle of the parietal bone, the groove in the latter being frequently converted into a complete osseous canal. The artery is here situated about one inch behind the external angular process of the frontal bone, and divides into numerous branches that radiate in all directions on the internal surface of the parietal and adjacent bones : these branches are principally lost on the dura-mater ; a few of them penetrate the sutures and supply the diploe of the bones. This artery has been frequently torn in injuries of the head, and has given rise to considerable hemorrhage between the dura mater and the bone. It may also be 94 BRANCHES OF THE INTERNAL MAXILLARY. wounded in the operation of trephining: the hemorrhage may, however, be easily controlled by the application of a dossil of lint. The posterior terminating branch curves backwards as it ascends on the internal surface of the squamous plate of the temporal bone. Its branches communicate with each other, and terminate in the dura mater and bone. The Tympanic artery is a very small branch ; it sometimes arises from that branch of the temporal which goes to supply the temporo-maxillary articulation ; it passes through the Glasserian fissure into the tympanum, and ramifies upon the membrane lining the interior of this cavity, and in the muscles contained within it. The Inferior dental artery arises from the inferior surface of the internal maxillary, nearly opposite the origin of the middle meningeal, and runs obliquely downwards and forwards, between the internal lateral ligament, and the ramus of the lower jaw. In this course it sends numerous branches to the pterygoid muscles, and to the gustatory and inferior maxillary nerves. Lower down it gives off a mylo-hyoidean branch which descends in the groove leading from the dental foramen, accompanied by the mylo-hyoidean branch of the inferior dental nerve, and supplies the mylo-hyoid muscle and mucous membrane of the mouth. Immediately after giving off this last branch, the inferior dental artery enters the dental foramen, in company with the dental nerve, which is situated in front of it. It descends beneath the alveoli, till it arives at the first molar tooth where it divides into two branches ; one of which is continued to the symphisis menti, supplying the alveoli of the canine and incisor teeth; the other escapes by the mental foramen, together with the mental branch of the inferior dental nerve, to supply the integuments, and triangularis and depressor labii inferioris muscles ; it anastomoses with the adjacent branches of the facial artery. In its course through the inferior maxillary bone it sends branches into the alveoli, BRANCHES OF THE INTERNAL MAXILLARY. 95 each of which penetrates the bottom of the tooth to be distributed on the membrane lining its cavity. The Meningea parva artery is not a constant branch : when it exists it arises from the internal maxillary, close to the origin of the inferior dental. Some of its branches are distributed to the soft palate and the nasal fossae : a principal branch of the artery passes upwards through the foramen ovale and supplies the inferior maxillary nerve, Casserian ganglion and dura-mater. The Posterior deep temporal artery arises from the internal maxillary, while the latter is passing between the two pterygoid muscles ; it ascends between the temporal and external pterygoid muscles; and then between the temporal muscle and the side of the cranium: to aLl these parts it sends numerous minute branches which ultimately terminate in anastomosing with the deep temporal branch from the superficial temporal artery. The Masseteric artery also arises in the triangular space between the two pterygoid muscles and ramus of the lower jaw. It passes outwards through the sigmoid notch that separates the coronoid process from the condyle of the inferior maxilla, and then descends on the outer side of its ramus, supplies the masseter muscle, and anastomoses with the tranversalis faciei artery. The Pterygoid branches are numerous : some of them are distributed to the internal pterygoid muscle, and a still greater number to the external pterygoid. The Buccal artery runs tortuously, downwards, forwards and outwards, between the two pterygoid muscles, and in company with the buccal nerve. Having arrived at the anterior margin of the ramus of the inferior maxillary bone, it penetrates the cheek and divides into a number of branches which are distributed to the platysma myoides, buccinator and zygomatic muscles, and also to the integuments of the cheek, and to its mucous membrane and follicles. It anastomoses with the facial, infraorbital, and transversalis faciei arteries : in some cases it 96 BRANCHES OF THE INTERNAL MAXILLARY. is deficient, and in others it arises from some other branch of the internal maxillary. The Anterior deep temporal artery usually comes off from the internal maxillary, as this artery lies between the external pterygoid and temporal muscles ; it ascends in the anterior part of the temporal fossa to supply the temporal muscle, and to anastomose with the other temporal arteries. Some of its branches penetrate the malar bone to reach the lachrymal gland, and communicate with the lachrymal artery. The Posterior superior dental artery descends tortuously on the back of the antrum. Some of its branches pierce the superior maxillary bone, and supply the molar teeth and mucous membrane of the antrum, while others are distributed to the teeth, gums, and buccinator muscle : they anastomose with the labial, buccal and infra-orbital arteries. The Infra-orbital artery passes through a canal of the same name in the floor beneath the orbit, in company with the infra-orbital nerve beneath which it lies. In this course it sends some small branches to the inferior rectus and inferior oblique muscles of the eye. Having arrived at the anterior part of this canal, it gives off the anterior superior dental branch, which descends through the anterior wall of the antrum, to supply its mucous membrane, and the canine and incisor teeth. After giving off this branch, it leaves the infra orbital canal, and is found on the face beneath the outer head of the levator labii superioris alseque nasi, and lying on the levator anguli oris. In this situation it supplies the adjacent muscles, and anastomoses with the facial, dental, buccal and nasal arteries. The Vidian artery, extremely small, passes backwards through the Vidian canal above the root of the internal pterygoid plate, and enters the aqueduct of Fallopious through the hiatus Fallopii. It supplies the facial nerve, Eustachian tube and pharynx, and anastomoses with the 97 BRANCHES OF THE INTERNAL MAXILLARY. pharyngea ascendens, and with the stylo-mastoid branch of the occipital artery. This vessel is sometimes given off by the trunk of the middle meningeal. The Superior palatine artery descends obliquely forwards through the posterior palatine canal. In this situation it sends two or three small branches through the accessory palatine canals to the velum palati. The continued trunk after leaving the posterior palatine canal advances on the roof of the mouth, and is distributed to its lining membrane, and to the gums and superior maxillary bone. At the foramen incisivum it communicates with the sphenopalatine arteries, which descend from the nose through the anterior palatine canals. The Spheno-palatine artery may be considered as the terminating branch of the internal maxillary. It passes through the spheno-palatine foramen into the cavity of the nose, where it gives off a pterygo-palatine branch, and then divides into its terminating branches. The pterygopalatine branch sometimes comes off directly from the interna] maxillary ; it passes backwards from its origin through the pterygo-palatine canal and supplies the pharynx and Eustachian tube. The terminating brcmches of the spheno-palatine are two or more in number : one of them descends on the septum nasi, with the sphenopalatine nerve, and communicates with the superior palatine artery : the others are distributed in the superior and middle meatus, in the antrum, and in the posterior ethmoidal cells : they communicate with the ethmoidal arteries, and form between the mucous membrane and periosteum, a vascular net-work, deeply tinging the former membrane. Sir B. Brodie tied the common carotid in consequence of hemorrhage from the posterior- superior dental branch of the internal maxillary artery after extraction of the second molar tooth of the upper jaw ; the hemorrhage, however, proved fatal.* In ordinary cases of this kind * Med. Chirurg. Trans, vol. viii. 11 Fig. \1.-Diuection of the Internal Maxillary, Middle Meningeal, and part of the course of the Facial, Arteries. A External Carotid Artery. B, B, Internal Maxillary Arteiy. C, C, Superficial Temporal Artery TFadeJArtery I, I, I, Vertical section through Frontal, Parietal and Occjp.tal Middle Meningeal Artery. P, Mental branch of Inferior Dental Artery. rBranch K 'to M the d "b, Branch to Parotid Gland Artery d, A twig from the Internal Maxillary to Internal Pterygoid Muscle. <>, Infenor -rw7l Artefv proceeding to the Dental Canal of the lower jaw. f, Buccal Artery, g, ?osterior Superior Dental Artery. h, Anterior deep Temporal Artery i, Posterior deep Temrroral Arteiy. 1, 1, 1, Distribution of the Middle Meningeal Artery afte entered the CreniunV?hVough the Spinous Foramen of the Sphenoid Bone, m. Artery of the Fd™ n Bnncli of Temporal Artery, o. Facial Artery ascending to upper hp and nose. 2™ 2 of Middle Meningeal ramifying beneath the Dura Mater. 3, 'i emporal Fossa 4, 4, Orbicidaris Palpebrarum Muscle. 5, 5, Zygomatic Arch cut through. nai piery *oid Muscle cut across. 7, Internal Pterygoid Muscle. 8 Kamus of the low or T.w nut 9 Masseter Muscle cut. 10, Buccinator. 11, Parotid Duct cut across. t T.wi S.merioriai AUeque Nasi. 13, Portion of Levator of the upper Lip. «j IZi % ZvwraitteSor 1,1'ari of Zygomatieus Major. 16, 16, Depressor LabU IXtorta 17, Orbicularis Oris Muscle. 18,18, Quadratus Monti Muscle divided. 99 INTERNAL CAROTID ARTERY. we may plug up the socket, or apply the actual cautery, or, if practicable, the tooth should be replaced. THE INTERNAL CAROTID ARTERY. This artery may be exposed in the following manner : The brain should first be removed in the usual way, leaving uninjured, however, the cerebellum, medulla oblongata and pons Varolii : the tentorium should now be removed, and the cerebellum pushed gently forward, or a small portion of its posterior part removed, so as to make room for the saw. A vertical section of the cranium should be next made through the posterior part of the occipital foramen and through the cervical vertebrae, behind their articular processes. This section will enable the student to study the medulla oblongata, vertebral arteries and their branches, and the eighth, ninth, and sub-occipital nerves. After these parts have been examined, the cerebellum and spinal marrow may be removed, and the ligaments divided which connect the occipital bone to the first and second vertebrae. The vertebrae may now be separated from the occipital bone, the recti capitis antici muscles having been previously detached from the front of the spine, but allowed to remain in connexion with the occipital bone. Lastly, the lower part of the neck may be cut across, and the digastric and styloid muscles, o, being first convex superiorly, and more in front convex inferiorly : as it passes through the sinus, it is crossed from behind forwards by the sixth nerve, which is closely applied to its external surface : the carotid plexus of nerves surrounds the artery within the sinus, and a branch or two of the sympathetic nerve may be observed ascending on its outside and joining the sixth nerve, as the latter is passing the carotid artery. More externally, and in the outer wall of the cavernous sinus, are situated the third, fourth, and ophthalmic branch of the 102 BRANCHES OF THE INTERNAL CAROTID. fifth nerve : these nerves are placed in their numerical order, from above downwards, and from within outwards. The lining membrane of the sinus is reflected on the artery and on the nerves in immediate connexion with it, thus forming a sheath which separates them from the blood of the sinus. On emerging from the cavernous sinus the artery pierces the dura mater and enters its fourth stage: on reaching the under portion of the anterior clinoid process it is here lodged in a deep notch, and makes a turn backwards and inwards, and terminates on the outside of the commissure of the optic nerves, and at the internal extremity of the fissure of Sylvius, by dividing into the posterior communicating and the anterior and middle arteries of the cerebrum. The arachnoid membrane gives a covering to the artery after it has entered into its fourth stage. Immediately after escaping from the cavernous sinus the internal carotid gives off the ophthalmic artery, and still later the choroid and posterior communicating arteries : it then terminates by dividing into the arteries already mentioned. The internal carotid artery gives off the following Tympanic. Vidian. Receptacular. Meningeal. Ophthalmic. Choroid. Posterior communicating. Anterior Cerebral. Middle Cerebral. The Tympanic branch is exceedingly slender ; it arises from the artery in its second stage, and passing through a portion of the bone, is distributed to the tympanum. The Vidian branch is a very minute twig, given off also in the second stage : it anastomoses with the vidian artery a branch of the internal maxillary. The Receptacular branches are small twigs given off by the artery in its third stage : they are distributed to the 103 OPHTHALMIC ARTERY AND BRANCHES. dura mater, to the walls of the inferior petrosal sinus, and to the pituitary body. The Meningeal branch is also distributed to the dura mater in the immediate vicinity, and anastomoses with the middle meningeal a branch of the internal maxillary. The Ophthalmic artery is given off from the internal carotid in its fourth stage, beneath the anterior clinoid process : it may be exposed by the following dissection : —The brain should be removed from the cranium in the usual way ; two vertical incisions should be next made, commencing, one at the external, and the other at the internal angular process of the frontal bone : if these be directed so as to meet posteriorly in the sphenoidal fissure, they will be found to include between them almost the whole of the roof of the orbit, which may be then readily detached with the hammer. The other parts contained within the cavity of the orbit may be exposed by the same dissection. Immediately after its origin the artery advances between the second or optic, and the third nerves, and enters the optic foramen, being lodged in a fibrous sheath formed for it by the dura mater. At first it lies on the outside of the optic nerve, then ascends to get on its superior surface, where it is covered by the levator palpebrse and superior rectus muscles, and accompanied by the nasal nerve : lastly, it runs horizontally forwards between the internal rectus and superior oblique muscles, towards the internal angular process of the frontal bone ; here it terminates by dividing into the nasal and frontal arteries, both of which escape from the orbit in company with the infra-trochleator nerve, passing above the tendo oculi and beneath the pulley of the superior oblique muscle. The ophthalmic artery gives off the following branches : Lachrymal. Central artery of the Retina. Supra-orbital. Ciliary. Muscular. Ethmoidal. Palpebral. Frontal. Nasal. 104 LACHRYMAL ARTERY. The Lachrymal artery is the first and one of the largest branches of the ophthalmic : it arises at the outer side of the optic nerve and passes forwards and outwards between the origin of the superior rectus muscle and the superior head of the external rectus : it supplies both Fig. 13. — Dissection of some of the branches of the Ophthalmic Artery, 1, Anastomosis between the Lachrymal and Superior Palpebral Arteries, 2, Levator Palpebral Superioris muscle. 3, The Lachrymal Gland. 4, Superior Oblique Muscle. 5, External Rectus muscle. 6, Optic nerve, a, Last turn of Internal Carotid Artery from which is given off the Ophthalmic Artery, c. Lachrymal Artery, d, Trunk of Ophthalmic Artery after having Passed beneath the Levator Palpebral and Superior Rectus Muscles. e, e, Anterior and Posterior Ethmoidal Arteries, f, Tendon of Superior Oblique Muscle after having passed through its pulley, g, Nasal Artery, h, Small portion of Superior Rectus Muscle, i, Supra-orbital Artery cut across. BRANCHES OF THE OPHTHALMIC. 105 these muscles, and is conducted by the superior margin of the latter towards the lachrymal gland : in this part of its course it sends a branch through the malar bone into the temporal fossa, which anastomoses with the anterior deep temporal artery. More anteriorly it gives off a number of branches which pass above, and sometimes round the lachrymal gland to penetrate between its lobules, and to supply its interior. Lastly, the terminating branches are lost in the upper eyelid, in anastomosing with the superior palpebral and anterior temporal arteries. The Central artery of the Retina is extremely minute ; it arises at the outer side of the optic nerve, pierces its coats, and runs forwards through its centre to arrive at the retina, on the internal surface of which it forms a vascular expansion which may be traced as far forwards as the ciliary processes. Immediately on escaping from the optic nerve, it gives off a branch, the Artery of Zvrm, which runs from behind forwards through the centre of the vitreous humour, and contained within a sheath formed by the hyaloid membrane, called the hyaloid canal: it sends numerous small branches to the hyaloid membrane : in front it ramifies on the posterior part of the capsule of the lens, and in the foetus its branches have been traced to the membrana pupillaris. This artery occasionally arises from one of the ciliary arteries. The Supra-orbital artery arises at the upper surface of the optic nerve and accompanies the nerve of the same name to the notch in the superior margin of the orbit. In this course it lies on the superior rectus and levator palpebral muscles, beneath the periosteum, and on the inside of the supra-orbital nerve. It supplies the levator palpebrse and superior rectus muscles; and as it passes through the notch in the superciliary arch, it gives a branch to the diploe of the frontal bone. It then divides into two principal branches, of which the internal is the larger : these subdivide into many others, which supply 106 CILIARY ARTERIES. the occipito-frontalis muscle, and anastomose with the angular artery inferiorly, and with the temporal artery superiorly. The Ciliary arteries are divided into three sets, —the short the long, and the anterior, and at their origins correspond to the upper surface of the optic nerve. The short ciliary arteries (twenty, thirty, or sometimes even forty in number,) advance tortuously through the fatty matter that envelopes the optic nerve, around which they form a vascular net-work. After frequent anastomoses they penetrate the sclerotic coat, near the entrance of the optic nerve ; some few of them terminate in this membrane, the rest proceed between the sclerotic and choroid coats. After forming by their frequent subdivisions and anastomoses a kind of vascular net-work on the exterior of the choroid, they pierce this membrane, and form an expansion of more minute vessels on its interior. .Having arrived at the ciliary body, some of them merely pass through it to arrive at the great arterial circle of the iris, but by far the greatest number terminate in the ciliary body, each ciliary process receiving so many as twenty or thirty branches : these take a tortuous course in the substance of the processes, and then reuniting into larger and fewer branches, terminate behind the iris by anastomotic arches. In most cases several of these ciLiary arteries come from some of the principal branches of the ophthalmic, and not directly from its trunk. The long ciliary arteries, usually two in number, pierce the sclerotic coat a little in front of the short ciliary, and then run from behind forwards between the sclerotic and choroid coats ; one on the inner side, and the other on the outer side of the eye. In this course they send a few delicate branches to the sclerotic coat, and still fewer to the choroid ; and having arrived at the ciliary body they subdivide into many branches which communicate with the short ciliary arteries and form an arterial circle at the ciliary margin of the iris. From this circle arise many small branches 107 MUSCULAR ARTERIES. which proceed towards the pupil in a radiated manner, and then bifurcate and anastomose with adjacent branches, so as to form a second arterial circle within the first. From this second circle arise smaller and more numerous branches than from the first; these proceed in a radiated manner to the pupillary margin of the iris, where most of them enter into the formation of a third arterial circle within the two preceding. In every instance the muscular arteries give off several ciliary branches which have been termed the anterior ciliary : these pierce the anterior part of the sclerotic coat, and communicate with the preceding. In speaking of the vascularity of the iris, Dr. Jacob observes :—" Much importance has been attached by anatomists to the manner in which these radiating vessels are disposed, in consequence of the representation of Ruysch, who exhibited them as forming a series of inosculations at a short distance from the pupil, since called the lesser circle of the iris. I do not deny that the vessels of the iris inosculate as in other parts of the body, but I do not believe that they present this very remarkable appearance, and I suspect that Ruysch exaggerated what he had seen, or described from an iris in which the injection had been extravasated and entangled in the tendinous cords, which I have described as extending from the fleshy bodies to the margin of the pupil. The question is fortunately of no importance. It is sufficient to know that the organ is amply supplied with arterial blood."* In the foetus, branches of the long ciliary arteries may be traced to the membrana pupillaris. In the operation of couching, the needle should be made to penetrate the eye below its centre, in order to avoid these vessels. The Muscular arteries arise at the upper surface of the optic nerve ; they are usually two in number : the inferior is a large and constant branch : after its origin it * Todd's Cyclopedia. 108 ETHMOIDAL AND PALPEBRAL ARTERIES. passes forwards between the optic nerve and the inferior rectus muscle : its branches are distributed to this muscle, to the inferior oblique and external rectus muscles, and to the lachrymal sac. The superior muscular artery is smaller and less constant: its branches are principally distributed to the levator palpebrae, and to the superior and internal recti muscles ; also to the superior oblique muscle, to the globe of the eye and the periosteum of the orbit. As we have already mentioned, the muscular arteries give off the anterior ciliary arteries. The Ethmoidal arteries are two in number; they arise at the inner surface of the optic nerve, and pass between the internal rectus and superior oblique muscles of the eye to arrive at the internal wall of the orbit. The posterior or larger enters the foramen orbitale internum posterius, and sends several delicate branches to the membrane of the posterior ethmoidal cells : others enter the cranium and descend into the nasal fossae with the filaments of the olfactory nerve, to be lost on the mucous membrane of the nose. The anterior ethmoidal artery, smaller than the preceding, accompanies the ethmoidal branch of the nasal nerve, and having entered the anterior internal orbital foramen, is distributed to the mucous membrane of the frontal sinus, and anterior ethmoidal cells and nasal fossae. The posterior branch frequently arises from the lachrymal or supra-orbital. The Palpebral arteries are two in number ; they arise at the inner surface of the optic nerve : the inferior descends behind the tendo oculi, and after sending some twigs to the lachrymal sac, divides into two branches, one of which supplies the inferior division of the orbicularis palpebrarum, while the other follows the adherent margin of the lower tarsal cartilage, and supplies this cartilage, the Meibomian glands, the conjunctiva and skin. The superior palpebral artery arises a little more in front, and after supplying the caruncula lachrymalis, is distributed in the upper eyelid, exactly as those of the inferior FRONTAL ARTERY. 109 artery are in the lower : it anastomoses externally with the lachrymal and temporal arteries. The terminating branches of the ophthalmic artery are the frontal and the nasal. The Frontal artery, usually smaller than the nasal, advances to the superior and internal part of the base of the orbit, from which it escapes in passing between the Fig. 14. —Branches of Ophthalmic Artery given off under the Superior Rectus Muscle. 1, Ball of the Eye. 2, External Rectus Muscle. 3, Insertion of Superior Eectus Muscle, cut and turned forwards. 4, Tendon of Superior oblique Muscle which passes underneath the Superior Hcctus. 5, Trochlea or Pulley for Superior Oblique Muscle. 6, Belly of Superior Oblique Muscle. 7, Superior Rectus Muscle divided. 8, Optic Nerve, a, Turn of Internal Carotid Artery (riving off the Ophthalmic Artery, b, Ophthalmic Artery, o, A twig to Superior Rectus Muscle, d, Muscular branche:. e, Continuation of Ophthalmic Artery cut across, f, f, Some of the short Ciliary Arteries. 110 NASAL, CHOROID, ETC. ARTERIES. tendo oculi and pulley of the superior oblique muscle. It then ascends on the forehead, between the frontal bone and orbicularis palpebrarum ; and subdivides, to supply this muscle, and the occipito-frontalis and corrugator supercilii. The Nasal artery is larger than the preceding, and with it escapes from the orbit between the tendo oculi and pulley of the superior oblique muscle : it then descends on the side of the root of the nose, and supplies the lachrymal sac, and adjacent muscles, and anastomoses with the termination of the labial or facial artery. In many cases the nasal artery seems to be perfectly continuous with the angular branch of the facial. In the operation for extracting the eye, the trunk of the ophthalmic is divided, and its sheath prevents it from retracting so as to bleed into the cavity of the cranium ; the hemorrhage into the cavity of the orbit is, however, frequently very considerable. After the ophthalmic, the next branch given off by the internal carotid is the choroid artery. The Choroid artery is a small but constant branch. It arises from the posterior part of the internal carotid, and passes backwards and outwards towards the crus cerebri: in its course it lies internal to and under cover of the internal convolution of the base of the middle lobe of the brain, and external to the posterior communicating artery: it then enters the inferior cornu of the lateral ventricle, supplies the tractus opticus and crus cerebri, the hippocampus major, pes hippocampi and corpus fimbriatum, and its terminating branches are distributed to the choroid plexus. The Posterior communicating artery arises from the internal carotid internal to the choroid ; it is a small but constant branch: from its origin it takes a direction backwards and inwards to anastomose with the posterior artery of the cerebrum, which is a branch of the basilar trunk. 111 ARTERIES OF THE CEREBRUM. After having given off the posterior communicating artery the internal carotid divides into two considerable branches, viz., the anterior and middle arteries of the cerebrum. The Anterior cerebral artery passes forwards between the first and second cerebral nerves, to reach the great longitudinal fissure; it then ascends with the corresponding artery of the opposite side between the anterior lobes of the brain, and in front of the anterior part of the corpus callosum, along the upper surface of which it runs, and then descends behind it so as nearly to circumscribe this commissure. The branches from its concavity are small, and distributed to the corpus callosum ; those from its convexity are more considerable and supply the internal surface of the hemispheres. The anterior arteries of the cerebrum are united by one or two transverse branches which complete the circle of Willis in front ; these are called the anterior communicating branches ; when there is but one, it is a large vessel; if more than one, they are proportionably small : on the anterior communicating branch or branches the ganglion of Ribes is situated. The Middle cerebral artery is larger than the preceding, and from its size, might be considered the continued trunk of the internal carotid; it sinks into the fissure of Sylvius, taking a direction outwards and backwards. It first gives a great number of branches to the inferior part of the brain, to the pia mater covering the crura cerebri, and one or more choroid branches which accompany the choroid plexus into the inferior cornu of the lateral ventricle. It then divides in the fissure of Sylvius into two considerable branches for the anterior and middle lobes of the brain ; these follow the fissure outwards and backwards, and terminate near the posterior part of the brain by numerous sub-divisions : some tortuous twigs are given off which sink into the anfractuosities and supply the pia mater; others appear to perforate and surround the roots of the olfactory nerve. 112 RETE MIRABLLE AND REXE OPHTHAXMICUM. The student should now impress on his memory the various important parts with which the internal carotid artery is connected, and the manner in which it may be affected either by disease or accident, in consequence of its vicinity to them. Thus its relation to the tonsil points out the danger of directing the knife too deeply backwards or outwards in opening abscesses of that gland. Beclard relates a case in which an itinerant quack destroyed a patient's life in this way. The vicinity of this vessel to the organ of hearing explains the various derangements of the functions of the latter, arising in consequence of an undue determination of blood to the head ; and, in certain cases, the hemorrhage from the ear which occurs in consequence of fractures extending to the base of the skull. I am not aware that there is any case on record of aneurism of the trunk of the internal carotid, though its branches are frequently the seat of this disease. In one case, however, in which Sir A. Cooper operated successfully, he was of opinion that the disease was in this vessel and not in the external carotid.* Near the base of the skull the internal carotid artery in graminivorous animals divides into several minute branches, which form a plexus of vessels called the rete mirabile of Galen; these subsequently unite into a single trunk, which afterwards divides into its cerebral branches. The use of this peculiar plexiform arrangement is to prevent the brain from being injured by the gravitation of the blood whilst the animal is grazing. A similar arrangement of the ophthalmic artery, '' rete ophthalmicum" has been observed at the back of the orbit in birds. * Med. and Chirur. Trans, vol. i. p. 229. 113 SUBCLAVIAN ARTERIES. These arteries are two in number, a right and left. The right subclavian arises from the arteria innominata, and the left from the arch of the aorta : each is usually described as having three stages. In the first stage it ascends from its origin to the internal margin of the scalenus anticus muscle: in the second stage it passes behind that muscle ; and in the third it proceeds obliquely downwards and outwards, till it arrives at the lower margin of the first rib, where it changes its name and becomes the axillary artery. In this course the artery forms an arch, the convexity of which looks upwards, and the summit of which is usually opposite to the sixth cervical vertebra. As the subclavian arteries differ in their origins, their relations must necessarily differ in the first stage, and, therefore a separate description will be necessary for each ; but in the second and third stages their relations are alike. First stage of the Right Subclavian. The right subclavian artery arises from the arteria innominata at the superior outlet of the thorax, immediately behind and on a level with the upper portion of the right sterno-clavicular articulation, corresponding to the interval between the two origins of the sterno-cleido-mastoid muscle; it then passes obliquely upwards and outwards, till it reaches the internal margin of the scalenus anticus muscle. In this part of its course it is covered anteriorly by the integuments, by the platysma myoides, except in the immediate neighbourhood of its origin, by the clavicular origin of the sterno-mastoid muscle, and by the cervical fascia, forming the sheath of this muscle ; by the sterno-hyoid and sterno-thyroid muscles, the former of which is in more intimate relation to the artery. Between the sternomastoid muscle anteriorly, and the sterno-hyoid and sterno-thyroid muscles and scalenus anticus posteriorly, an interval exists in which we find a quantity of loose areolar tissue together with several veins, one of which, sometimes i 114 RIGHT SUBCLAVIAN ARTERY. of considerable size, passes across the posterior surface of the inferior portion of the sterno-mastoid muscle, and establishes a communication between the anterior and external jugular veins: it is sometimes endangered in the operation for wry neck. When these parts have been removed, the artery will be found covered more immediately by the internal jugular vein close to its junction with the subclavian vein to form the right vena innominata : the union between these two veins usually takes place in front of the internal margin and close to the insertion of the scalenus anticus muscle, in which situation the commencement of the vena innominata lies upon a plane anterior, and a little inferior to the artery : lower down, on account of their difference of obliquity, they become more distant, the vein lying on the outer side. The vertebral vein as it is about to terminate in the internal jugular, usually passes anterior to the artery. In front of the artery we observe also the superior and middle cardiac nerves descending; and near the origin of the vessel, the pneumogastric nerve, and sometimes its recurrent branch, (which in this situation occasionally begins to detach itself from its parent trunk,) are situated in front of it. Vieussens describes a plexiform appearance upon the pneumogastric nerve in this situation, corresponding to the origin of the recurrent, and which he calls the plexus gangliformis ; these nerves therefore pass between the artery and the vena innominata. The phrenic nerve also forms an anterior relation of the subclavian artery : immediately after this nerve has passed from off the scalenus anticus muscle, it gets under cover of the internal jugular vein close to its junction with the subclavian, and insinuates itself into a small interval which exists between the origin of the thyroid axis and the inner margin of the muscle; and it is in this situation that the nerve lies in front of the right subclavian artery in its first stage : generally speaking it does not lie in direct contact with the artery, but is borne from off this vessel 115 LEFT SUBCLAVIAN ARTERY. by the origin of the internal mammary artery, anterior to and across which the nerve usually passes. Sometimes the phrenic nerve Lies upon a plane posterior to the internal mammary artery. Posteriorly the first stage of the right subclavian artery is related to the recurrent nerve, inferior cardiac nerve, and still farther back to the trunk of the sympathetic nerve where it forms its inferior cervical ganglion : this ganglion is situated behind the artery close to the origin of the vertebral. The longus colli muscle, with the interposition of some loose areolar tissue, lies behind the artery : the apex of the cone of the pleura lies a little inferior, to the outside, and on a plane posterior to the vessel. First stage of the Left Subclavian artery. The left subclavian artery arises within the cavity of the thorax, from the arch of the aorta opposite to, and to the left side of the second dorsal vertebra, and ascends slightly outwards into the neck, till it reaches the internal margin of the scalenus anticus muscle, where the second stage commences. Like the common carotid artery, the first stage may be divided into two portions,—a thoracic and cervical: the thoracic portion extends from the origin of the vessel from the arch of the aorta to the upper outlet of the thorax; and the cervical extends from this point to the internal margin of the scalenus anticus. In its thoracic portion it is related, internally, to the left carotid artery, which is also situated on a plane anterior to it; to the oesophagus, thoracic duct and recurrent nerve, which are on a plane posterior to it, and to the internal jugular vein and its junction with the subclavian to form the left vena innominata : these large veins are also situated on a plane anterior to the artery : externally it is related to the top of the left lung and pleura: anteriorly it is covered by the sternum, sterno-clavicular articulation and sterno-hyoid and sterno-thyroid muscles : it is overlapped by the left lung and pleura, and it is crossed obliquely near its origin by the left pneumogastric nerve : the phrenic nerve is anterior to and parallel with the arteiy. The left vertebral vein lies anterior to it, and on the same i 2 116 SECOND STAGE OF THE SUBCLAVIAN. plane we find the origin of the left vena innominata as already described : posteriorly the artery corresponds to the second dorsal vertebra at its origin, afterwards to a short portion of the spinal column above this vertebra, to the longus colli muscle, and to the sympathetic nerve and its inferior cervical gangHon. The cervical portion is very short : it has anterior to it the parts already mentioned as lying in front of the artery of the right side ; in front of it also we find the internal jugular vein, with the vagus and phrenic nerves. The latter nerve, at the inner margin of the scalenus anticus muscle, passes inwards towards the middle line and crosses in front of the artery at the termination of the cervical portion of its first stage ; and the terminating portion of the thoracic duct, as it is about to enter the posterior part of the left subclavian vein at its junction with the internal jugular, lies anterior to the artery in this situation. From the preceding account it follows that the left subclavian artery differs in the following respects from the right: the left subclavian is longer and proportionably more slender ; it arises within the cavity of the thorax, and from the arch of the aorta ; it is situated at the left side of the spine which here forms a concavity, and it is in close relation with the left side of the second dorsal vertebra : for these reasons it lies much deeper, and farther removed from the surface than the right : its direction is also more vertical, and consequently nearly parallel to the pneumogastric and phrenic nerves; it is intimately connected with the oesophagus and thoracic duct and left longus colli muscle, and it is covered in front and externally by the left lung and pleura: the internal jugular vein is nearly parallel with it internally, whilst at the right side the internal jugular crosses in front of the subclavian artery:—lastly, the left subclavian vein lies superior to a considerable portion of the artery in its first stage, and also internal to it ; whilst on the right side the vein is inferior to the artery. 117 THIRD STAGE OP THE SUBCLAVIAN. Second stage of the Subclavian arteries. —Each of the subclavian arteries in its second stage is covered, anteriorly by the integuments, platysma, cervical aponeurosis, clavicular origin of the sterno-cleido-mastoid muscle ; and frequently immediately behind this muscle, by the transverse branch of communication between the anterior and external jugular veins; and by the scalenus anticus muscle which separates the artery from the subclavian vein ; the latter vessel lying lower down, and covering the insertion of the muscle. The phrenic nerve is usually enumerated amongst the anterior relations of the subclavian artery in the second stage ; and from the obliquity of its course across the anterior surface of the scalenus anticus muscle, until it becomes related to the internal mammary artery, it may be considered, properly speaking, as an anterior relation both to the first and second stages of the artery. Posteriorly the artery is related to the apex of the cone of the pleura and to the scalenus posticus muscle ; the brachial plexus of nerves lies on a plane posterior to the artery in this stage and partly accompanies the artery into its third stage. Third stage of the Subclavian arteries. Each of the subclavian arteries in its third stage takes a direction obliquely downwards and outwards, and having arrived at the lower margin of the first rib changes its name, and becomes the axillary artery. In this course it is covered anteriorly by the clavicle and subclavian muscle, immediately above which it has other important relations, which we may now proceed to study. On raising the integuments, platysma and fascia, together with some of the supra-clavicular branches of the cervical plexus of nerves from off the front of the artery, we usually observe a space between the trapezius muscle on the outside, and the sterno-mastoid on the inside: in some cases, however, the fibres of these muscles meet at their clavicular attachments, so that in order to expose the artery, it becomes necessary to divide transversely some of the fibres of the 118 LIGATURE OP FIRST STAGE OF SUBCLAVIAN. trapezius. In the deeper layer or stratum, we observe the posterior belly of the omo-hyoid muscle passing at first horizontally inwards, and then slightly upwards and inwards towards the larynx. A triangular space is thus formed, bounded inferiorly by the clavicle, internally by the posterior margin of the sterno-mastoid muscle, and externally by the posterior belly of the omo-hyoid ; in this space which is called the posterior inferior lateral triangle of the neck, the artery may be felt emerging from behind the scalenus anticus muscle accompanied by the brachial plexus of nerves. If we were to judge of the size of this space by the appearance it presents in the dissected subject, we would be led into great error. It is, in fact, hardly appreciable while the muscles which bound it preserve their natural relative position, though dissection may make it appear of considerable extent. The brachial plexus lies behind the artery, but a large portion of it projects at its outer or acromial side. The vein is situated on a plane anterior to the artery, but inferior and nearer to the middle line. The anterior thoracic nerve begins to descend in front of it in the lower part of this stage ; and lastly, it is crossed anteriorly by the transveralis humeri artery, which runs in this situation nearly parallel to the clavicle. Posteriorly it rests on part of the scalenus posticus, on the inferior fasciculus of the brachial plexus, on the origin of the middle thoracic nerve, which supplies the lesser pectoral muscle, and on the first rib. In operations on the axillary artery and about the shoulder, the artery may be easily compressed against the rib for the purpose of preventing hemorrhage. OPERATION OF TYING THE FIRST STAGE OF THE SUBCLAVIAN ARTERY. This operation has been performed in about ten cases ; in nine upon the first stage of the right subclavian, and in one upon the first stage of the left: all these cases were attended with fatal results. 119 LIGATURE OF THE SUBCLAVIAN ARTERY IN THE FIRST STAGE. No. Operator. Date of Operation Results and Observations, 1 Colles, ... 1811 Death, from hemorrhage, on 4th day. 2 Mott, Death, from hemorrhage, on 18th day. 3 Hayden, 1835 Death, from hemorrhage, on 12th day. 4 O'Reilly, 1836 Death, from hemorrhage, on 23rd day. 5 Partridge, ... Death, from pericarditis and pleuritis, on 4th day. 6 Liston, Death, from hemorrhage, on 13th day. 7 Liston, Death, from hemorrhage, on 36th day. 8 Auvert, Death, from hemorrhage, on 22nd day. 9 Auvert, Death, from hemorrhage, on 11th day. 10 Rodgers, 1845 Death, from hemorrhage, on 15th day. Professor Colles's case. The ligature was passed round the artery but not tightened till the fourth day, great dyspnoea and oppression about the heart having occurred. On the 9th day the patient complained of sensation of of strangling and pain about the heart. He then became delirious, and died in a few hours.* Mr. Hayden's case. '' ElizaMoulang, aged 57, unmarried, and of intemperate habits, states, that in November, 1834, she perceived a small pulsating tumor, of the size of a pea, about an inch and a half below the right clavicle, and at an equal distance from the sternum. In April, 1835, it had increased to the size of a marble, and was for the first time attended with pain, which was of a lancinating character. This recurred at intervals till August, after which it remained permanently, being however attended with increased severity at intervals. " August 22, 1835. She was seen by Dr. Ireland, Messrs. Wilmot, O'Beirne, and Hayden, for the first time. " Sept. 7. The patient was admitted into the Anglesey Hospital. On examination, a large pulsating tumor was * Edin. Med. and Surg. Jour. 1815. 120 MR. HAYDEN'S CASE. observed situated internally to the axilla, parallel to the upper edge of the pectoralis minor, and extending above the clavicle : it is circumscribed, and has pulsation referrible to its inferior part. There is considerable tension on the upper portion of the tumor, the size of which can be diminished by pressure. Comparing the clavicle of this side with the opposite one, the former appears somewhat displaced, being pushed upwards. The arm, forearm, and hand were much swollen and cedematous some days since, and ' bruit de soufflet' was audible over the tumor. " The results of stethoscopic examination were not unfavourable in reference to the operation for this disease, which is declared to be aneurism of the subclavian artery extending to the scalenus. She now describes the pain as darting through the tumor to the back of the shoulder, and down to the elbow. She also complains of an almost insupportable sense of weight and numbness in the whole extremity, although the swelling of it is inconsiderable. Operation. —On September 15, 1835, Mr. Hayden proceeded to perform the operation in the following manner: "The patient was placed on the back upon a large table, furnished with mattrass and bolsters; head slightly depressed, and turned to the left side. First incision, commenced nearly at the left sterno-clavicular articulation, traversed the upper margin of the sternum and clavicle, and terminated beyond the posterior or acromial margin of the sterno-mastoid muscle, having divided the integuments and platysma, including subjacent adipose tissue of about a quarter of an inch in depth. Second incision, commenced about four inches above the sternum, a little to the left of the mesial line of the neck, so as to terminate by falling at right angles on the commencement of the first incision, dividing the parts to the same depth : two sides of a triangle were thus formed, the apex at the sternum. The flap, consisting of integument, platysma, and adipose layer, was raised from the apex upwards and MR. HAYDESf's CASE. 121 outwards ; the outline of the sterno-cleido-mastoid was now very distinct, but still covered by the superficial fascia ; the latter was carefully divided immediately above the sternum, corresponding to the anterior edge and lower extremity of the sternal portion of the sterno-cleido-mastoid. A director was next introduced beneath this muscle, the fibres of which were divided at about a quarter of an inch from the sternum and clavicle, and precisely parallel to its origin. The muscle was now raised upwards and outwards with the handle of a scalpel: a small vein was here tied. In the next stage of the operation, the sterno-hyoid and sterno-thyroid were divided upon a director. Hemorrhage from a small artery and vein so inundated the part, that it was found necessary to secure them before the operation was proceeded with. After the displacement of some cellular structure with a director, the innominata, carotid, and subclavian were felt; compression of the last mentioned vessel suspended pulsation at the wrist and tumor. The first part of the subclavian was found not involved in the disease, and, consequently, it was decided that this vessel should be tied in preference to the innominata, which had been clearly exposed, and which, from its direction, and being uninterfered with by the clavicle, seemed to offer much less obstacle to the passage of the ligature; this was, at first, attempted with an aneurism needle, made of silver, in order that it might be bent so as to present a degree of concavity to the clavicle, to be determined by the displacement of this bone, and the depth of the artery. The eyed part of the needle, for about an inch, was made to slide off and on, like the canula of a trocar, so that when the extremity of the needle was brought around the artery, the eyed portion, with the ligature, might be withdrawn. But when the handle of the instrument was depressed, the upper part slipped from the lower before the latter had passed under the artery. The vessel was subsequently secured with Mr. L'Estrange's needle. 122 mr. o'reilly's case. On the 25th, though positively forbidden, she got out of bed, and walked about the room. Subsequently at two o'clock p. m. she would not suffer the nurse to pass the bed-pan under her, but got out of bed ; while in the act of doing so, and rising upon her right hand placed upon the bed, considerable hemorrhage suddenly set in. The patient died on the 27th, twelve days after the operation. The artery at the site of the ligature, was gaping irregulary for three-fourths of its calibre ; the remaining fourth was sound, and retained the ligature."* Mr. 0' 'Reilly''s case. —" Thomas Duffy, aged 39 years, a man of robust frame, and 20 years employed as helper in a stable, was admitted into Jervis-street Hospital, April 15, 1836, under the care of Mr. O'Reilly for aneurism of the right subclavian artery. He lias lived a life of continued intemperance, always drinking, but never incapable of attending to his duty. The aneurismal tumor was distinctly circumscribed, of a somewhat oval shape, and measuring in transverse diameter two inches and a half, and in the vertical direction two inches. The pulsation could be distinctly felt in all parts of the tumor, and pressure on the subclavian artery not only commanded the pulsation of the sac, but even diminished its contents to the degree of rendering it flaccid—finally, the bruit de soufflet was distinctly audible over all its surface. The first time he observed this tumor was in February last, and since that time he thinks it has made little progress. The symptoms he complained of on admission were, numbness of his fingers and uneasy sensations in his arm and forearm, with occasional cramps since last Christmas. For the last eight or nine weeks he has been obliged to remain almost constantly in bed, with his arm extended from his body, as he suffered considerable pain whenever * Lancet, 1837. MR. O'REILLY'S CASE. 123 he walked about for any time, or approached his arm to his side ; in bed, however, with his arm extended he is quite free from pain. His general health did not seem impaired, and his heart and lungs were sound, judging from careful physical examination. On the whole he appeared to be a favourable subject for the operation which was decided on at a consultation held with the hospital surgeons : the patient being informed of the nature and urgency of his symptoms, expressed his willingness to submit to any operation which would give him relief. Accordingly at two o'clock the following day (September 16), Mr. O'Reilly proceeded, with the assistance of his colleagues, to perform the operation. Operation. The patient being placed in Heurteloup's bed, with his head slightly depressed and turned to the left side, so that the light from the sky-light might fall into the deep space in which the artery was imbedded, Mr. O'Reilly commenced the operation in the following manner, standing by the patient's right side. He first drew down the integuments of the lower part of the neck over the clavicle with his left hand, and then cut freely on the bone, beginning his incision about the centre of the clavicular origin of the right sterno-mastoid muscle and terminating it over the trachea, opposite the centre of the sternal origin of the left sterno-mastoid muscle ; this incision was about four inches in length. The next incision was made through the integuments along the internal margin of the right sterno-mastoid, and terminating inferiorly in the centre of the preceding incision ; in the same line the superficial fascia and platysma were divided successively on a director. The sternal origin and internal half of the clavicular origin of the right sterno-mastoid muscle were divided transversely close to the bone, and detached. On introducing the finger, the line of the carotid artery could be distinguished, and its pulsation felt. The deep fascia was next divided and a 124 MR. O'REILLY'S CASE. little of the internal margins of the sterno-hyoid and sterno-thyroid muscles, so as to expose the carotid artery, the sheath of which was cautiously opened by pinching a small portion of it with a forceps, and dividing the raised portion of it horizontally. A blunt silver instrument the size of a small scalpel, with a round point was used in the subsequent steps of the operation. The carotid artery being taken as a guide, the subclavian artery was easily exposed lying at the bottom of a very deep cavity. The jugular vein was drawn outwards by means of a curved spatula, and the pneumogastric nerve inwards by a similar instrument. Mr. L'Estrange's needle, armed with a three-threaded ligature, was passed round the artery from below upwards with facility, and without disturbing the artery in its situation. The ligature being tightened round the vessel, the edges of the wound were brought into contact, and retained so by two strips of adhesive plaster: the operation occupied only twenty-five minutes, and not more than a teaspoonful of blood was lost. Three hours after the operation he felt comfortable and well in every respect, and heat and sensation were the same as in the opposite arm. Subsequently the patient had repeated hemorrhages, and died upon the twenty-third day. Post-mortem examination. —The divided extremities of the subclavian artery were patulous and separated nearly two inches by coagula ; their edges were jagged and irregular, and there seemed not to have been the slightest attempt at the reparative process. The distal end of the artery was of the natural size. External to the scalenus anticus there was a sudden enlargement of the artery or aneurismal swelling, which extended four inches to the commencement of the axillary artery. On its upper and outer surface were stretched the brachial nerves. About an inch from the commencement of the tumor the clavicle passed over it, and made a depression in it. The arteria innominata was healthy and the heart natural: the trachea 125 MODE OF PERFORMING THE OPERATION. red externally, and pale internally, was filled with a frothy mucus. A small portion of the upper part of the lung was hepatized. Bronchitis of the right lung,—left lung healthy,—no effusion into the thorax. A second aneurism about an inch in diameter was found on the axillary artery in the first stage of its course. The account of this case is abridged from the notes of Mr. Banon, one of the Surgeons of the Hospital. Mode of performing the operation —The patient should be placed in the same position as in that recommended for tying the arteria innominata. The first incision should commence immediately above the sternum, at the internal margin of the sterno-mastoid muscle, and be continued horizontally outward along the anterior and upper portion of the clavicle for the extent of about three inches : the second incision, about two inches long, should descend along the internal margin of the same muscle, so as to terminate inferiorly in the internal extremity of the preceding incision. The flap of integument thus formed is to be dissected up, and the lower part of the sterno-mastoid exposed. Behind this muscle a director should be now introduced, on which its sternal and part of its clavicular origin should be divided. In a similar way the origin of the sterno-hyoid, and then that of the sternothyroid, should be cautiously divided. By scraping through some areolar tissue we may now get a view of the carotid artery, and by passing the finger between this vessel and the jugular vein which is situated more externally, the subclavian artery may be felt. It is crossed near its origin by the pneumogastric and recurrent nerves which must be drawn inwards, and the needle is to be carried round it from below upwards and inwards, on the inside of its vertebral branch. The cardiac filaments of the sympathetic nerve should be avoided, and the operator should bear in mind the vicinity of the top of the pleura, as it may be wounded in performing this operation. 126 LIGATURE OF FIRST STAGE OF LEFT SUBCLAVIAN. Operation of tying the Left Subclavian Artery in its first stage. It has heretofore been generally considered impracticable to tie the left subclavian artery in its first stage for the following weighty reasons : —it extends for a very short distance indeed above the first rib, and then makes a short turn ; it is moreover, covered in front in this situation by the subclavian vein and phrenic nerve. Its deep situation, and almost vertical direction, its parallelism to the carotid artery and pneumogastric nerve, and its intimate connexion with the thoracic duct and pleura, present a complication of unusual difficulties. Velpeau, however seems to have a different opinion, for after enumerating the differences between the two subclavian arteries in their first stage, he observes : "It is important to note all these differences, as they show us that it would be much less dangerous to apply a ligature here than on the right side, because being placed at a greater distance from the origin of the vessel, the adhesive clot would form without difficulty. It would likewise be easier in its execution, for the nerves do not cross it as on the right, but descend parallel to its direction into the chest, and might be readily separated. Nevertheless, it must be admitted, that almost all these advantages are counterbalanced by the greater depth, and almost vertical direction of the artery. It must be remembered also that the pleura is more intimately related to the first stage of the left subclavian than at the right side, a circumstance which materially adds to the danger of this operation and to the difficulties in isolating the artery." The left subclavian artery in its first stage was tied in the Living individual by Dr. Rodgers of New York. " The patient was a man, aged forty-two, who, in consequence of lifting a heavy weight, upwards of a month previously, suddenly became the subject of aneurism of the left subclavian artery. The operation was performed on the 14th of October, 1845. Two incisions were made ; one, three inches and a half in length, along the inner border of the Fig. 15.— Some of the relations of the Left Carotid and Left Subclavian Arteries in the cervical portion of their first stage. A, Left Common Carotid Artery- B, Left Subclavian Artery. C, Internal Jugular about to join I), the Left Subclavian Vein;—the Jugular and Subclavian Veins displaced outwards. E, Anterior Jugular Vein in its course behind the Sterno-mastoid Muscle. F, Deep Cervical Fascia. (>, Lett Steino Mastoid Muscle divided, and separated from g. g, its Sternal and Clavicular origins. H, Left Sterno-hyoid Muscle cut. I, Left Sterno-thyroid Muscle cut K, Right Steruo-hvoid Muscle. L, Right Sterno-mastoid Muscle. M, Trachea. N, Projection of the Tliyniid Cartilage.' O, Hollow, Internal to Stemo-mastoid Muscle. P, Situation where the Subclavian Arteiy passes behind the Clavicle, Q, Sternal end of left Clavicle. R, Right Stenio-thyroid Muscle, b, Left Pneumogastric Nerve, d, Left Anterior Scalenus Muscle f, f, Layers of the Cervical Fascia. 128 dr. rodger's case. sterno-cleido-mastoid muscle, terminating at the sternum, and dividing the integuments and platysma-myoid muscle; and the other, two inches and a half in length, extending horizontally over the inner extremity of the clavicle, the two meeting at a right angle near the trachea. Several small veins having been ligated, and the flap thus formed dissected up, the sternal portion with half of the clavicular of the mastoid muscle was divided upon a grooved director, a procedure which fully brought into view the sternohyoid and omo-hyoid muscles and the deep-seated jugular vein, all covered by the cervical fascia. A part of the aneurismal sac was also in sight, overlapping a considerable portion of the anterior surface of the scalene muscle, upon which the operator could distinctly feel the phrenic nerve. By digging with the handle of the knife, and fingers, the deep cervical fascia was now divided close to the inner edge of the scalene muscle, when, after a little search, the subclavian artery was easily discovered as it passed over the first rib, pressure upon this portion readily arresting the pulsation of the tumor. The next step of the operation consisted in passing the ligature around the vessel without injury to the pleura and thoracic duct, but this proved to be one of extreme difficulty, owing to the great narrowness and depth of the wound, the latter nearly equaling the length of the forefinger. This, however, was at length successfully accomplished by means of an aneurismal needle with a moveable point, carried from below upwards. The moment the ligature was tied all pulsation in the tumor ceased, and the patient, if not entirely comfortable, made no complaint of any kind. The wound became somewhat erysipelatous after the operation, but, on the whole, the patient got on well until the 26th of October, when, on changing his position in bed, hemorrhage supervened, and continuing to recur at various intervals, destroyed him on the fifteenth day. On dissection, the wound was found to be filled with clotted blood, beneath which the artery had been completely LIGATURE OF SECOND STAGE OF THE SUBCLAVIAN. 129 divided by the ligature, which lay loose close by. The stump of the subclavian, between the aorta and the point of ligation, was about an inch and a quarter in length, and thoroughly impervious to air and liquids, its caliber being occupied by a solid and firmly adherent coagulum. The distal extremity of the subclavian contained a soft imperfect clot, while the vertebral artery which was given off immediately at the site of the ligature, was almost patulous, and had evidently been the seat of the hemorrhage which caused the patient's death. The aneurismal sac, the size of a small orange, was completely blocked up with coagula: the thoracic duct was uninjured, but the pleura at the bottom of the wound was found to be extensively lacerated, and through the opening thus formed a large quantity of blood had passed into the left cavity of the chest."* Operation of tying the Subclavian artery in its second stage. This operation is not generally practised in this country, both on account of its supposed difficulty and the dangerous consequences apprehended. The difficulty has, however, been exaggerated. With moderate care the scalenus anticus muscle may be divided without injuring the jugular vein, phrenic nerve, or scapular branches of the thyroid axis ; and, though it be not desirable to tie an artery so close to one of its branches, yet there is every reason to believe that the absence of coagulum on the cardiac side of the ligature, does not necessarily preclude the possibility of success. Still it must be borne in mind, that the top of the pleura lies close to and immediately behind the artery in this situation, and may be injured by the aneurism needle ; and again, the ligature in this stage would include the artery close to the origin of the superior intercostal and cervicalis profunda. The operation was originally suggested by Dupuytren,;}; * Gross' System of Surgery, vol. i. p. 909. | Lecons Orales, voL iv. p. 530. K 130 LIGATURE OF THIRD STAGE OF THE SUBCLAVIAN. and Dr. Auchincloss performed it on the left subclavian artery .* Operation of tying the Subclavian artery in its third stage. This operation has been frequently performed for aneurism, and wounds of the axillary artery. Mr. Ramsden first tied the artery in the year 1809 : since then it has been frequently the subject of successful operation. Dr. Post of New York first performed this operation with success in 1817, and Mr. Liston afterwards, in the year 1820 : finding the artery diseased at the commencement of its third stage, Mr. Liston cut across the external half of the scalenus anticus muscle and in this situation included the artery in a ligature. + In this city the operation in the third stage has been performed by Professor Colles, Professor Porter, Dr. Hutton, Mr. Ellis and others. The following method is recommended in order to expose this vessel—the patient should be placed lying on a table of convenient height, with the shoulders elevated, so that the light may fall directly on the parts exposed. The first incision should commence at the external margin of the sterno-mastoid muscle, immediately above the clavicle, and be continued transversely outwards for the extent of about three inches. The platysma-myoides and fascia may now be divided on a director to the same extent. Some operators prefer dividing these three layers at once by cutting down on the clavicle after having previously pushed the shoulder upwards : such an incision will of course be above the clavicle when the shoulder is again depressed in order to continue the operation. In many cases, however, of large aneurism, these motions of the shoulder would be impossible. The lips of the wound should now be separated by retractors, and any fibres of the trapezius muscle which advance beyond its outer angle, * See Edin. Med. and Surg. Jour. vol. 45. f Edin. Med. and Surg. Jour. No. 64. LIGATURE OP THIRD STAGE OF THE SUBCLAVIAN. 131 should be carefully divided on a director. The external jugular vein which now presents itself should be drawn to the sternal extremity of the wound : if, however, it should happen to lie more towards the acromial side, it should be drawn outwards : lastly, if it cross the centre of the incision, or if there be a second external jugular in this situation, it may be necessary to include it in two fine ligatures and divide the vessel between them. A plexus of veins which usually next presents itself, should be separated with the handle of the scalpel, but injured as little as possible, as the further steps of the operation will be considerably obscured by the blood which these vessels throw out. The omo-hyoid muscle may be observed a little above the clavicle, from which point it ascends obliquely upwards and inwards. In a case operated on by the late Professor Todd, this muscle lay below the clavicle, and it became necessary to draw it up and divide it before the artery could be exposed. Connecting the margin of this muscle to the adjacent margin of the scalenus anticus, a strong fascia will be found, through which the operator should cautiously tear with his nail. The finger may now be passed behind the outer margin of the scalenus anticus muscle, in order to search for the subclavian artery. It should be borne in mind that the transversalis humeri artery lies nearly in front of the subclavian, passing horizontally either behind, or immediately above the clavicle : the circumstances of its smaller size, and its crossing in front of the scalenus anticus muscle, may assist in distinguishing it. The difficulty of at once finding the subclavian has, however, occasionally been found greater than would have been expected a priori : the artery when exposed frequently contracts and its pulsation ceases; the margin of the scalenus anticus is rendered indistinct by its connexion with fascia, and the welling of blood, the depth of the artery and alteration of the relative position of the part caused by the aneurismal tumor pushing up the clavicle, together with an enlargement of one or two 132 WARDROP's OPERATION ON THE SUBCLAVIAN. lymphatic glands, present difficulties, that require the greatest presence of mind, judgment, and knowledge of anatomy on the part of the surgeon. It has been suggested by Professor Hargrave, under these circumstances, as well as for the purpose of allowing the artery to be gently relaxed after having been secured, to saw through the clavicle. * Cruveilheir has also advocated a similar practice. Dupuytren recommends that some of the outer fibres of the scalenus anticus muscle should be divided if necessary, and this may be easily effected without injuring the phrenic nerve. We have seen that Mr. Liston was obliged to divide the fibres of this muscle. The subclavian artery has been tied for aneurism of the arteria innominata in conformity with the recommendation of Mr. Wardrop. We have seen that the carotid artery has also been tied upon the same principle. A few words of explanation as to the rationale of this operation, called the application of the "distal ligature," may be useful at the present stage of the subject. It will be remembered that the Hunterian operation for the cure of aneurism consisted in the application of a ligature upon the artery between the heart and the aneurismal sac: the object held in view in this operation was the prevention of the direct flow of blood through the main channel into the tumor; this was followed by the coagulation of its contents, and ultimately by its entire absorption. The mode of operating for aneurism, known by the name of the distal ligature, was orignally suggested by Brasdor, and was recommended by him in cases where no branch would intervene between the ligature and the sac ; and where the surgeon could not well tie the artery between the tumor and the heart. It was supposed that, if no branch originated from the aneurism, or from the artery either above or below the aneurism, the blood would coagulate in the tumor, and that a cure * Hargrave's Operative Surgery, p. 44, and Dublin Quarterly Journal for February, 1849, p. 53. WARDROP'S OPERATION ON THE SUBCLAVIAN. 133 would be accomplished by the absorption of the coagulum and the subsequent contraction and absorption of the sac. The principle upon which a cure is expected to follow this mode of operating is the same as that upon which varicose veins of the leg are treated, by making pressure upon the superior part of the saphena vein : the blood becomes obstructed in the vessel, a coagulum is formed, and an obliteration of the venous channel is accomplished. Mr. Wardrop reports the successful termination of the case in which he performed the operation already mentioned. He was moreover induced from various considerations, to apply the principle suggested by Brasdor to the cure of aneurismal tumors of certain arteries, by applying a ligature, not upon the artery itself, but upon one of the branches of the diseased trunk: he imagined that this would be sufficient to diminish the momentum of the circulation through the aneurism, and so produce a consolidation of the tumor and subsequent cure of the disease. In 1827 he was consulted by a patient, a female, who had an aneurism of the arteria innominata, the tumor had advanced into the neck, and made such pressure upon the carotid artery as to prevent the circulation of the blood through it. He was of opinion that a ligature placed now upon the subclavian artery alone, would effect a consolidation of the aneurismal tumor ; accordingly in the month of July of that year, he tied this artery in its third stage. There was no secondary hemorrhage, the operation was unattended by any unfavourable results. On the 22nd day the ligature came away and the wound healed. The pulsation in the common carotid artery, however, returned upon the ninth day. Some months after the operation, two newly formed swellings, which were engrafted upon the old one, had made their appearance, and the aneurism continued to enlarge. Symptoms of bronchial inflammation made their appearance, diarrhoea set in ; general anasarca took place, and she died twentythree months after the performance of the operation. 134 DR. HOBART'S CASE. Mr. Wickham, Surgeon to the Winchester Hospital, was consulted by a patient, a man aged 55 years, labouring under an aneurism of the arteria innominata. On September 25th, 1839, a ligature was placed on the carotid artery immediately above the omo-hyoideus muscle : the ligature came away on the fourteenth day after the operation. It was determined that the subclavian artery should be tied shortly afterwards, but the patient left the hospital contrary to advice and remained out for a considerable length of time. On his re-admission, however, the subclavian artery was tied in its third stage; the tumor increased in size, hemorrhage took place, and the patient ultimately sank.* The subclavian and carotid were both tied in their first stage upon the same patient by Dr. Hobart of Cork, in the year 1839. The case was supposed to be one of aneurism of the arteria innominata, and the patient a female of about twenty-five years of age. On a consultation being held of the principal surgeons in Cork, it was unanimously agreed that, in order to give the patient a chance, the distal operation should be performed. Accordingly, in the presence of a large body of medical men, among whom were Sir James Pitcairne and other military surgeons, also Drs. Bullen, Murphy, Howe, Coracodjattachmfnt of Pectoralis Minor divided and pendulous. M, Coraco-brachiahs Muscle and Perforans Cusserii Nerve. N, Biceps. O, Latiss.mus Dorsi crossed by *«^ e rves of Wnsberg. P, Teres Major Muscle. Q, Brachial Fascia. It Sternal end of Clavicle. S, Ce P tatto Veto passing between the Deltoid and Great Pectoral Muscles, and then in front of the Pec- Sr»Hnor, to enter the Axillary Vein, a Axillary Vein. *a, with Internal Cutaneous Nerve, b, Axillary Artery with the two heads of the Median Nerve. *b Brachial Artery and Vense ComiteB. BRANCHES OP THE AXILLARY. 165 inside of the left arm, than is usually observed after a simple dislocation of the head of the humerus. The deep axillary swelling remained stationary for some days, but no pulsation could be discovered either in it or in the arteries of the limb. A feeble and frequent pulse could be felt in the left subclavian, and in all the other arteries, as well as in the heart. After the space of ten days, Mr. Wallace's month of attendance having expired, the case came under the care of Mr. O'Reilly, who having been satisfied that a diffused aneurism existed, and was on the increase, performed the operation, at which the writer was present, of tying the subclavian artery in the third stage of its course. The patient recovered and was discharged from the hospital about two months afterwards ; he lost the last two fingers by gangrene, but whether from an attack of erysipelas, which succeeded the operation, or from the effects of the ligature of the main artery of the limb, is not clearly known. The man lived for many years afterwards in the immediate vicinity of the Richmond Hospital. The axillary artery gives off the following branches :— Acromial, or Thoracica- Acromialis. Thoracica Suprema. Thoracica Alaris. Thoracica Inferior. Infra, or Sub-scapular, Posterior Circumflex. Anterior Circumflex. The Acromial or Thoracica acromialis artery arises from the axillary in its-first stage ; it is a short thick axis ; it arises a little below the clavicle and passes forwards above the edge of the pectoralis minor muscle, which it separates from the subclavius muscle and ligamentum bicorne. It then advances towards the interval between the deltoid and pectoralis major muscles, and after sending some branches to the serratus magnus, pectoral and subclavius muscles, it terminates by dividing into a superior and inferior branch. The superior branch passes horizontally outwards beneath the deltoid muscle, and is lost in sup- 166 BRANCHES OP THE AXILLARY. plying the latter and the supra-spinatus muscle, and the scapulo-humeral and acromio-clavicular articulations. The inferior branch, or thoracica-humeraria, turns spirally round the cephalic vein, and descends with it in the areolar interval between the deltoid and great pectoral muscles, and is distributed to these muscles and to the integuments. The acromial artery anastomoses with the supra-scapular and posterior circumflex. The Thoracica Suprema artery arises from the first stage of the axillary ; sometimes it arises separately a little beneath the preceding, but more frequently it is a branch of the acromial. It generally runs for some distance along the upper margin of the pectoralis minor, and then descends obliquely inwards between it and the pectoralis major, to both of which muscles it sends several branches : it also supplies the mammary gland and integuments, and anastomoses with the intercostal and internal mammary arteries. The Thoracica Alaris artery is seldom found as a single trunk, its place being usually supplied by several smaller vessels : its origin is from the second stage of the axillary. It divides into many branches which supply the areolar tissue and glands of the axilla. In removing diseased glands from this cavity, the incautious division of the branches of this artery may be followed by smart hemorrhage, which will be difficult to control on account of the divided vessels retracting into the areolar tissue : to provide against this occurrence Professor Colles advised a ligature to be passed round the vessel supplying the gland before it is divided. The Thoracica Inferior, called also the thoracica longa or external mammary artery, arises opposite the lower margin of the pectoralis minor, or frequently whilst the artery is under cover of that muscle in its second stage; it then descends obliquely inwards, concealed by the lower edge of the pectoralis major: it supplies these muscles, and likewise the serratus anticus, intercostals, mammary gland BRANCHES OP THE AXILLARY. 167 and integuments, and anastomoses with the other thoracic arteries, the internal mammary, and the intercostal arteries. The Infra or Sub-scapular artery is of considerable size : it arises from the third stage of the axillary, opposite the inferior margin of the sub-scapular muscle, to which it sends one or two branches, and then descends along its inferior margin till it reaches the internal edge of the long head of the triceps. Here it divides into an inferior and posterior branch : the inferior branch continues in the direction of the trunk, and descends between the serratus magnus and latissimus dorsi muscles, to both of which, and to the teres major, its branches are distributed : at the inferior angle of the scapula it anastomoses with the posterior scapular artery. The posterior branch, larger than the inferior, sinks into a triangular space bounded above by the teres minor and sub-scapular muscles, below by the teres major and latissimus dorsi, and externally by the long head of the triceps, which, in this situation, separates it from the posterior circumflex artery : this branch supplies freely the muscles bounding this triangular space, and then curves round the axillary margin of the scapula to arrive in the fossa infra-spinata, being in this part of its course covered by the teres minor and by the infra-spinatus muscle. Here, lying close to bone, it divides into many branches, which supply the infra-spinatus muscle and shoulder joint and anastomose with the posterior and superior scapular arteries. The infra or sub-scapular artery sometimes arises in common with the posterior circumflex. The Posterior Circumflex artery is a little smaller than the preceding vessel, and arises close to it from the posterior part of the axillary artery in its third stage : immediately after its origin it sinks into a quadrangular space, bounded above by the sub-scapular and teres minor muscles, inferiorly by the tendons of the teres major and latissimus dorsi, anteriorly by the humerus, and posteriorly by the long head of the triceps: in passing through 168 THE SCAPULAR ANASTOMOSIS. this space it winds round the surgical neck of the humerus, accompanied by the posterior circumflex nerve. After giving a few branches to the teres minor and sub-scapularis muscles, and to the shoulder-jont, it sinks beneath the deltoid muscle, into which it sends numerous branches, which anastomose with the supra-scapular, acromial and anterior circumflex arteries. The Anterior Circumflex artery is a very small but very constant branch: it passes horizontally forwards and outwards, covered by the coraco-brachialis muscle and short head of the biceps. It then crosses the bicipital groove, covered by its synovial membrane and by the long head of the biceps, and sinks beneath the deltoid muscle, in the substance of which it anastomoses with the posterior circumflex artery. The anterior circumflex artery supplies the coraco-brachialis, biceps and sub-scapularis muscles. While crossing behind the long head of the biceps, it sends a delicate branch upwards along the bicipital groove, to supply the head of the humerus and capsular ligament of the shoulder joint. It will be useful in the present stage of the dissection to take a glance at the principal arteries which form what is termed the scapular anastomosis. By means of this free arterial communication around the scapula, the blood of the subclavian artery will readily find its way into the arm or forearm in cases where the subclavian has been tied in its second or third stages, or where the axillary artery has been tied in its first or second stages. Along the axillary margin of the scapula we observe the continued branch of the sub-scapular artery passing towards the inferior angle of that bone : along the posterior or vertebral margin we see the posterior scapular passing towards the same point; and in relation with the superior or coracoid meirgin we find the supra-scapular artery. At the inferior angle of the scapula a free communication exists between the posterior scapular and sub-scapular arteries ; at the posterior superior angle a similar communication exists between the posterior and supra-scapu- Fig. 21.-r-Represents the Arteries of the Posterior part of the Neck and Shoulder. The Scapular Anastomosis. 1, 1, Occipital portion of Trapezius Muscle of each side. 2, 2, 2, Arterial branches to the Trapezius and Latissimus Dorsi Muscles. 3, Sterno-cleido-mastoid Muscle. 4, Splenius. Capitis. &, Splenius Colli. 6, 6. Levator Anguli Scapulae. 7, Lower portion of Sternomastoid. 8, Serratus Posticus Superior. 9, Khomboideus Minor. 10, Rhomboideus Major divided. 11, 11, Aponeurosis covering long Muscles of Back. 12. Clavicle with Arterial twig. 13, 14. Spine of Scapula with Arterial Twigs. 15, Insertion of lnfra-spinatus Muscle. 16, Capsule of shoulder joint. 17, Teres Minor. 18, Long Head of Triceps between the two Teres Muscles. 19, Teres Major, 20, Deltoid divided and turned downwards. 21, 21, 21, Serratus Magnus with Arterial twigs. 22, Latissimus Dorsi divided and turned over, a, Occipital Artery emerging from underneath the Splenius Muscle to get into its third stage. b, b, Posterior Scapular Artery. c, c, c, Terminating branch of the Posterior Scapular Artery, d, e, Cervicalis Superncialis Artery cut. f, Twig to the Clavicle, g, Small branch to Supra-spinatus. i, Supra-scapular Artery, k, Infra Spinata Artery. 1, Acromion process, m, Posteiior Circumflex Artery, n, n, Anastomoses between the Infraspinata, the Posterior branch of Subscapular and Posterior Scapular Arteries. o, o, Branches of the Intercostal Arteries. P, P, P, Dorsal branches of the intercostal Arteries. 170 VEINS OF THE ARM AND FORE-ARM. lar arteries ; and at the glenoid angle, underneath the root of the acromial process, a free anastomosis takes place between the supra-scapular and the sub-scapular arteries. Thus the axillary and subclavian arteries communicate freely with each other. VEINS OF THE ARM AND FORE-ARM. Before proceeding with the dissection of the brachial artery the student is recommended carefully to examine the superficial veins of the arm and fore-arm ; for this purpose he should remove the integuments from off the front of these parts, when the veins and superficial nerves will be exposed lying between the skin and fascia. Venisection is usually performed at the bend of the elbow, because there are in this situation a number of superficial veins, easily made prominent and easily compressed. On the outside of the bend of the elbow we observe the cephalic vein ascending, having derived its principal origin from the cephalic vein of the thumb. On the inside we see the basilic vein, which seems to be a continuation of the small vein of the little finger, termed vena salvatella. On the middle line of the front of the fore-arm we see the median vein, which, as it approaches the elbow-joint, divides into an internal and external branch : the internal branch is the median basilic vein, it crosses in front of the brachial artery at a very acute angle, being separated from it immediately beneath the bend of the elbow, by the semilunar process of the biceps tendon, called also the semilunar fascia of the biceps : some of the branches of the internal cutaneous nerve pass in front of it, and others behind it. The external branch, smaller than the internal, is termed the median-cephalic vein; it ascends obliquely upwards and outwards, in front of the trunk of the external cutaneous nerve, to join the cephalic vein. The basilic and cephalic veins being thus reinforced, ascend in the arm, the former along the internal, and the latter along the external margin of the biceps 171 VEINS OF THE ARM AND FORE-ARM, muscle. The basilic vein unites with the vense comites of the brachial artery, and the large vessel formed by their union becomes the axillary vein. In the middle of the forearm, near the bend of the elbow, the median vein, before it gives off its median basilic and median cephalic veins, receives at its posterior surface, from the deepseated parts of the fore-arm, a vein called the mediana-profunda. When the operation of venisection is determined on, the student will observe that the median basilic is the vein which presents itself most prominently ; and if this be selected for the operation, great caution will be necessary, in order to avoid wounding the brachial artery which lies beneath it. On this account the student is Fig. —22. Represents portion of the Surgical Anatomy of the Fore-arm. A, Fascia over the Biceps Muscle. B, Basilic Vein and Internal Cutaneous Nerve. C, Brachial Artery and the Venaj Comites. D, Cephalic Vein and External Cutaneous Nerve coming out from behind it- E, Median Cephalic Vein and a communicating vein to the Venae Comites. F, Median Basilic Vein. G, Radial Artery. H, Lymphatic Gland. I, Radial Artery seen through an opening made in the fascia. K, Ulnar Artery and Ulnar Nerve. L, Falmaris Brevis Muscle. 172 BRACHIAL ARTERY. advised to select the median cephalic vein in preference, at all events until he has become somewhat expert in performing the operation. A wound of the artery during venisection may be denoted by the blood issuing in jerks, and being of a bright arterial colour. These appearances may exist, however, without any such wound, and therefore need not always excite alarm ; on the contrary, the artery may be punctured without any particular symptom to indicate the accident. When there is reason, from the great force with which the blood is projected, to suspect that this accident has occurred, and there is no pain, swelling, nor effusion present, we may apply a graduated compress, keep the limb quiet, and wait the result, which may be various. Sometimes the wounded vessel may heal without any unpleasant consequence : in other cases, the external wound of the vein is healed, but the wound in the posterior wall of the vein may form an adhesion with the wound in the anterior wall of the artery, and thus there remains a direct communication between the artery and vein. When this direct communication exists between the two vessels, the affection is termed aneurismal varix ; but if the areolar tissue intervening between the two vessels has been distended into the form of a sac, which establishes a medium of communication between the artery and vein, then the disease is termed varicose aneurism. The latter is the more serious, as it may terminate in aneurism of the artery: but it is seldom that either of them requires any operation. The student may now remove the veins and brachial aponeurosis so as to expose the brachial artery. THE BRACHIAL ARTERY. This artery is a continuation of the axillary : it commences opposite the lower margin of the teres major and latissimus dorsi tendons, passes obliquely downwards and outwards, and terminates nearly opposite the coronoid BRACHIAL ARTERY. 173 process of the ulna : on the removal of the integuments, the artery will be found lying under cover of the brachial aponeurosis. After the aponeurosis has been removed, the vessel will be seen overlapped by the fleshy belly of the coraco-brachialis muscle, then by the biceps muscle, and still lower down covered by the semilunar fascia derived from the tendon of the biceps : these are its anterior relations : internally it is related, in addition to the integuments and fascia, to the basilic vein, to the inferior profunda artery and to the ulnar and internal cutaneous nerves ; externally it is related to the coraco-brachialis and biceps muscles, and to an areolar interval placed between the biceps and brachialis anticus; posteriorly it corresponds first, to the triceps muscle, from which it is separated by the superior profunda artery and musculospiral nerve; next it rests on the insertion of the coracobrachialis muscle; and, in the remainder of its course, it lies upon the brachialis anticus. The brachial nerves surround the artery, and are related to it in the following order; behind it, but accompanying it merely for a short distance, is the musculo-spiral nerve : the external cutaneous nerve at first descends along its outer side, separating it from the coraco-brachialis muscle; but lower down it inclines outwards, perforates the last named muscle, and loses its relation to the artery. The internal cutaneous nerve lies at first on the inside of the artery, being situated on the front of the ulnar nerve, which it consequently separates from the median : lower down the branches of the internal cutaneous nerve become superficial, and one principal filament covers the artery at its termination. The ulnar nerve descends on the inside of the vessel, but towards the middle of the humerus separates from it, and inclines still more internally and accompanies the inferior profunda artery; and lastly, the median nerve lies on the outside of the brachial artery above; but lower down, at about the junction of the lower with the two upper thirds of the arm, it crosses the artery, 174 BRACHIAL ARTERY, usually over its anterior surface, in order to arrive at the inner side of the vessel. The veins accompanying the artery are two in number, and are termed venoe comites : about the middle of the arm they unite with the basilic vein, which usually perforates the brachial aponeurosis in this situation. Such are the relations of the brachial artery in its course down the arm. At its Fig. 23.— Represents the Arteries of the upper extremity, which are seen when the skin and fascia have been removed. A A, Brachial or Humeral Arteiy. B B, Radial Arteiy. C, Ulnar Arteiy. K, Muscular branch to the Bracliialis Anticus. O, Snperficialis V0I03 Arteiy. PP, The Superficial Palmar Arterial Arch, formed by the Ulnar and Superficialis Vol® Arteries. Q, Digital Artery of thumb. S, Twig to the Palmaris Brevis Muscle. V, Princeps Pollicis Arteiy, running along the internal margin of the thumb, a, Twig to the Triceps, b, Small branch to Coraco-brachialis and Biceps, c, Superior Profunda about to enter between the two portions of the Triceps, d, Inferior Profunda, arising opposite the insertion of the Coraco-brachialis Muscle, e, f, Muscular Branches, g, h, Small twigs to tho Biceps, i, The Anastomotic Arteiy. 1, Radial Recurrent Arteiy. m, Twig to the Pronator Teres and Flexor Carpi Radialis Muscles, n, Branch to the Supinator Radii Longus. r, The Radialis In dicis Artery, t, t, t, t, The four Digital Arteries, u, u, u, u, The Arches formed by the Digital Arteries. 1, Portion of Pectoralis Major. 2, The Deltoid Muscle. 3, Upper portion ot Biceps Muscle. 4, Coraco-brachialis. 5, Triceps. 6, Belly of Biceps. 7, Internal Intermuscular Septum. 8, Short portion of Triceps. 9, Brachialis Anticus. 10, Tendon of Biceps. 11, Semilunar Fascia from Biceps Tendon. 12, Pronator Teres. 13, Internal Condyle. 14, Supinator Radii Longus Muscle. 15, Pronator Teres crossed by Radial Artery. 16, Flexor Carpi Radialis. 17, Palmaris Longus. 18, Flexor Carpi Ulnaris. 19, Extensor Carpi Radialis Longior. 20, Portion of Flexor Digitorum Sublimis, or Perforatus. 21, Extensor l'rimi Internodii Pollicis. 22, Extensor Ossis Metacarpi Pollicis. 23, Palmar Aponeurosis. 24, Tendons of the Superficial FTexor, crossed by the Superficial Palmar Arch of Arteries. 175 LIGATURE OF BRACHIAL ARTERY. termination it sinks into a triangular space, in front of the elbow joint, bounded on the outside by the supinator radii longus, and on the inside by the pronator radii teres muscle ; the latter muscle overlapping the artery in this situation. In this space it lies on the brachialis anticus muscle, having the tendon of the biceps to its outside, the median nerve to its inside, while in front it is covered by an aponeurotic slip of a semilunar form, sent downwards and inwards from the tendon of the biceps muscle to join the anti-brachial aponeurosis a little below the internal condyle : this is called the semilunar fascia of the biceps ; its upper margin is concave and directed upwards and inwards ; its insertion into the fascia of the fore-arm is much broader than its origin from the tendon of the biceps. The Operation of tying the Brachial artery. This operation may become necessary for the cure of aneurisms of this vessel, or in consequence of a wound inflicted on it or upon the radial, ulnar, or interosseous arteries. True Aneurism of the brachial artery, or that form of the disease which consists in a dilatation of all the coats of the vessel, is extremely rare : Pelletan mentions an example of it in his " Clinique Chirurgicale," which Dupuytren stated was the only authentic case of the kind he knew of.* Aneu/rism of the Brachial artery depending upon a diseased condition of its coats, is also very rare. Mr. Liston observes, —" I have treated but one such case ; it occurred in the person of an old ship carpenter. Whilst at work as usual, he felt something snap in his arm ; a pulsating tumor was soon afterwards noticed, and before I was asked to see him by Mr. Cheyne of Leith, it had attained, during four months, fully the size of a hen's egg, and was evidently in part composed of solid matter. * Lecons Orales, vol. i. p. 265. 176 ANEURISMS OP BRACHIAL ARTERY. The brachial was tied and every thing went on favourably."* Diffused False Aneurism. By far the most frequent forms of aneurism of the brachial artery are those which are the result of injuries inflicted upon the vessel, as in the operation of venisection at the bend of the elbow. When the artery has been unfortunately wounded, the following results may happen; the blood may escape freely from the wound in the artery, and may pass into the areolar tissue of the limb to a greater or less extent : in some cases the extravasation of arterial blood is so considerable, as to reach nearly as high up as the folds of the axilla, and for a certain distance also below the elbowjoint ; this has been termed a diffused false aneurism. This form of aneurism may occur also, from too great an amount of pressure having been applied to the sac for the cure of the next variety we shall speak of, namely, the circumscribed false aneurism, the sac gives way and the blood becomes diffused through the limb. An instance of this kind is recorded by Mr. Ellis, one of the Surgeons to Jervis-street Hospital; he observes, " the pressure having been too forcibly applied, the sac gave way and a diffused aneurism became established, "f Circumscribed False Aneurism. After the infliction of a wound upon the artery, the blood may escape at once directly through the external wound ; if pressure be now made upon the wound, the general diffusion of the blood may be prevented, and a process of thickening may be set up in the areolar membrane surrounding the small quantity of blood which has insinuated itself between the wound in the artery and the integuments; this thickened areolar membrane becomes matted together by the effusion of coagulable lymph, and is ultimately converted into the cyst of the aneurism, which communicates with the canal * Prac. Surg, p, 206. f Clin. Surg. p. 69. 177 TREATMENT OP BRACHIAL ANEURISMS. of the wounded artery : this has been termed a circumscribed false aneurism. Aneurismal Varix, and Varicose Aneurism, form two other varieties of aneurismal tumors resulting from a wound of the artery during venisection : these two have been already considered ; the student will, however, do well to recollect that in the former there is a direct communication between the artery and the vein, whilst in the latter an intervening sac is situated between the two vessels. We shall now consider the treatment applicable to these four varieties of brachial aneurism, the results of wounds inflicted upon the artery. With regard to the circumscribed false aneurism, Professor Harrison remarks, "I do not recollect a case of this sort of circumscribed aneurism, from the infliction of a simple wound, in which it has been necessary to open the sac or tie the artery below it; I am, therefore, disposed to place full reliance on the practice of simply laying bare the vessel as close to the tumor as circumstances will permit, and tying it with a single ligature. Professor Colles, whose experience and great opportunity for observation render every practical remark of his worthy of attention, thus expresses himself on this subject in his course of lectures on the Theory and Practice of Surgery : "I have operated repeatedly, and with success, for the cure of circumscribed brachial aneurism, in consequence of injury to the artery in performing venisection, I have also frequently assisted others in operating for the same cause, and with the same result; and I never yet found it necessary to open the aneurismal sac, or to look for the vessel below the tumor, or to apply more than one ligature around the artery, which, I think, ought always to be tied as near as possible to the seat of the disease ; for in this species of aneurism the coats of the vessel have not N 178 TREATMENT OF BRACHIAL ANEURISMS. undergone any morbid change, as is generally the case in aneurism of the inferior extremity."* Mr. Cusack has treated three cases of circumscribed aneurism at the bend of the elbow from wounds in venaesection, by compression, f The compresses were applied chiefly upon the tumor, the compressing force was moderate ; the limb was bandaged with the '' gantelet," from the fingers upwards, according to Genga's method : blood was taken from the patient by venisection, digitalis administered, and absolute rest and low diet enjoined. The two first cases terminated favourably under this treatment; during the treatment of the third case, the circumscribed aneurism became diffused. Scarpa adopted this mode of compression for the cure of circumscribed brachial aneurisms. The method of treating aneurism, by compression of the artery leading to the anewrismal sac, has been successfully employed by Dr. Hutton in a case of circumscribed aneurism of the brachial artery at the bend of the elbow : the patient was a servant, aged 34 : he had been bled by a " country bleeder" for a pain in the chest. On his admission into the Richmond Hospital, the aneurismal tumor was circumscribed and about the size of a pullet's egg ; it pulsated strongly and presented the usual characters of aneurism. Dr. Carte's compressing apparatus was employed ; '' with this the patient maintained the compression during six hours in succession ; at the end of this period all pulsation had ceased and never returned. "J If, however, these methods should fail in obliterating the sac of a circumscribed brachial aneurism, the surgeon may tie the artery leading to the tumor with a single ligature ; and in addition, compression of the entire limb, from the fingers as far as the elbow, should be employed. Surgeons are now generally agreed as to the proper * Surgical Anatomy of the Arteries, pp. 185-6. t Dublin Journal, vol. i. pp. 117, &c. % Medical Press for May 16th, 1849. TREATMENT OF BRACHIAL ANEURISMS. 179 mode of treatment in cases of diffused false aneurism of the brachial artery : the single ligature, whieh may be sufficient in the circumscribed aneurism, is not to be depended on in this form. When the wound in the vessel is large, when the extravasation of blood becomes considerable, when the tumefaction of the limb extends upwards along the arm, and occupies also the upper portion of the fore-arm, accompanied with pain and discoloration of the integuments, compression will be worse than useless, and the single ligature on the artery leading to the wound will not suffice; the free anastomoses of the vessels about the elbow joint will allow the blood to flow freely from the wounded artery, and the hemorrhage will continue without control. In a case of this description, therefore, the only operation which can with confidence be relied on, is to cut down with a free incision upon the wounded vessel, to turn out the coagulum of blood, and to tie the artery above and below the wound. In speaking on this subject Professor Harrison observes ; "I now believe that very few cases of diffused aneurism, either of this or any other artery, will admit of cure from the simple operation and application of a single ligature to the artery above the injured part, but that it will be almost always necessary to lay open the tumor by a long incision, which should include, if possible, the original wound.—- When the injured vessel shall have been exposed, it may be raised by a probe, either introduced into it through the wound, or the aneurism needle can be passed around it, and the artery tied first above and then below the opening."* Professor Porter observes :—" But there is still another case ; and let us suppose a limb, into which a quantity of blood has been extravasated, not sufficient to cause a gangrene of the part, but still too abundant to admit a hope of its being absorbed. Here, I apprehend, the surgeon has no choice; he must cut down, turn out all the * Surgical Anatomy of the Arteries, pp. 180, &c. N 2 180 TREATMENT OF BRACHIAL ANEURISMS. coagula he can reach, in this way getting rid of that which would be a subsequent source of irritation, and then tie the vessel above and below the aperture."* We are anxious, however, to impress upon the mind of the student, that in cases of simple puncture of the brachial artery, as in venisection, or where there is no extensive effusion of arterial blood to create alarm, there is no necessity for immediate operation. The constitutional disturbance consequent upon the wound, and the alarm into which the patient is thrown from the agitation and terror betrayed by the unsuccessful operator, at the instant when he is aware of the mischief he has done, added to the shock sustained by the alarm and precipitancy of a hasty operation performed under such circumstances —all contribute to induce such a state of the patient's system as to render it very unfavourable for the healing of the wound, and secondary hemorrhage has been known to result from such unnecessary interference. In cases, therefore, not demanding immediate operation, the student is recommended to apply judicious compression by means of graduated compresses laid carefully one over the other upon the wound, so as to correspond to the orifice of the bleeding vessel, and to surround all by means of a figure of 8 bandage, coiled round the elbow a sufficient number of times to secure the compresses in their proper situation. Another form of bandage has been preferred by some surgeons, it is called the " gantelet" of Genga ; it consists of narrow strips of bandage with which each finger was enveloped separately; these met above the wrist, from which point a broader roller was carried round the fore-arm, and round the elbow over the compresses which had been previously applied : the bandage was also carried round the arm up towards the axilla. This mode of treatment by compression, in conjunction with proper position, absolute rest, low diet, &c, * Porter on Aneurism, p. 138. LIGATURE OF THE BRACHIAL ARTERY. 181 has proved in such cases decidedly successful, and until it fail, the operation is unnecessary and may be mischievous. With regard to the treatment required for aneurismal varix, and for the varicose aneurism, we have already observed that it is seldom that either of them requires any operation: the method of compression already alluded to, either upon the diseased part, or upon the brachial artery leading to it, may be employed with considerable advantage. Dr. William Hunter advised that nothing should be done in the way of operation in these cases where there should be no considerable alteration in the tumor. Sir A. Cooper entertained the same objection to the operation. If, however, the disease should continue to increase in size, if a thinning of the integuments over the tumor, or over the sac, as in the varicose aneurism, should occur so as to threaten an effusion of blood into the limb, or from an ulcerated opening in the integuments, the surgeon will be obliged to tie the brachial artery, not with a single ligature passed round the vessel leading to the aneurism, but having cut into the sac and having turned out the coagulum, he should tie the artery both above and below the wound in the vessel. Operation of tying the Brachial Artery in the superior third of the arm. The arm being abducted and rotated outwards for the purpose of diminishing the depth of the wound, an incision, about two inches and a half long, may be made over the ulnar margin of the coraco-brachialis muscle, the belly of which may be felt through the integuments. This should be done with much caution, as the integuments are thin in this situation, and the basilic vein may sometimes, though rarely, lie superficial to the brachial aponeurosis ; moreover, the internal cutaneous nerve lies here immediately underneath the skin. The fascia being next divided on a director to the same extent, the areolar tissue may be scraped through 182 LIGATURE OF THE BRACHIAL ARTERY. with the handle of a knife till the artery and nerves are brought into view. The vein formed by the union of the basilic vein with the vense comites, together with the internal cutaneous and ulnar nerves, may be drawn to the inside, and the median nerve to the outside, and the needle passed from within outwards. The separation of the artery and nerves will be facilitated by flexing the limb. The operator will bear in mind the possibility of a high bifurcation, and of the superior profunda artery arising from the posterior circumflex and assuming the position of the brachial artery. Ligature of the Brachial Artery in the middle of the arm. The elbow joint being extended and the arm rotated outwards, an incision should be made, about two inches and a half long, on the internal margin of the biceps muscle. Having divided the integuments and drawn the vein or veins out of the way, the fascia should next be divided on a director. In some cases the basilic vein lies beneath the fascia in this situation. By drawing outwards the biceps muscle with a blunt retractor, the artery may be exposed, with a small vein frequently lying on either side, and the median nerve usually in front of it. The nerve is to be drawn to the inside, and the needle passed from within outwards. The operator should remember that internal and posterior to the brachial artery, in this situation, the inferior profunda artery descends in company with the ulnar nerve, the nerve lying to the inner side : to avoid tying the latter artery in mistake, he should first take care to direct the edge of his knife, not backwards, but towards the centre or axis of the humerus, and afterwards satisfy himself that the compression of the vessel stops the pulsation in the aneurismal tumor. Should there be two vessels, and that the compression LIGATURE OF THE BRACHIAL ARTERY. 183 of both be found necessary to cause the pulsation of the sac to cease, both of them should be tied. If the operation be performed in the inferior third of the arm, the surgeon will meet with the internal cutaneous nerve and basilic vein in his first incisions ; and after having cut through the brachial aponeurosis he will look for the biceps tendon, the inner edge of which will be his guide to the artery in this situation: the median nerve will be found still more internally, lying at the inner side of the artery. Ligature of the Brachial Artery at the bend of the elbow. The elbow-joint being extended, the hand supinated, an incision may be made, commencing at the internal margin of the median basilic vein, about an inch above the internal condyle, and carried downwards and a little outwards for above two inches and a half, along the radial margin of the pronator radii teres muscle. The vein and external lip of the wound being drawn outwards, the fascia and semilunar process of the biceps tendon may be successively divided on a director. At the bottom of the wound will be found the biceps tendon externally, the median nerve internally, and the artery between both and a little behind them. The needle may then be passed behind the artery from within outwards. Several small branches of the internal cutaneous nerve are necessarily divided in this operation. The superficial veins should be carefully kept out of the way; if one of them, however, should unavoidably interfere with the operation, Velpeau advises to " cut it between two ligatures, or even without this precaution, if not very large." If the operation be performed for a wound in the artery accompanied with an extravasation of arterial blood, we should cut through the sac and turn out the coagulated blood : the surgeon will be obliged, generally speaking, to relax the tourniquet in order to ascertain the situation 184 BRANCHES OP THE BRACHIAL. of the orifice in the bleeding vessel, and by the introduction of a probe in the opening he will be able still more clearly to discover its precise situation and extent. Having raised the artery from its bed and separated it from the median nerve, a double ligature should be passed beneath it : this ligature should be afterwards divided into its two separate portions, and the artery secured above and below the wound. This is the treatment which Scarpa recommends for diffuse aneurism following a wound of the brachial artery. The surgeon would however do well to remember that where there has been a considerable extravasation of blood as the result of the wound of the artery, into the areolar tissue of the limb, the relative position of the parts will be greatly altered from that which we have just described. The entire of the bend of the elbow may be found filled with coagulated blood and enormously distended, so that in order to obtain a view of the tendon, or of the nerve or artery, it will be essentially necessary to turn out completely the coagula, and then only can he expect to discover the bleeding vessel. The branches of the brachial artery as it passes along the arm are the following :— Superior Profunda. Arteria Nutritia. Inferior Profunda. Anastomotic. Muscular. The Superior profunda artery arises a little beneath the conjoined tendons of the teres major and latissimus dorsi muscles, and then sinks, in company with the musculospiral nerve, into a canal formed by the three heads of the triceps muscle and the bone. From the back of the humerus it winds round to its outside in a spiral groove, which may be observed on that bone beneath the insertion of the deltoid muscle : here it divides into two branches, an anterior and posterior. The anterior pierces the ex- 185 BRANCHES OF THE BRACHIAL. ternal intermuscular ligament, and, accompanied by the musculo-spiral nerve, descends in a groove between the brachialis anticus and supinator longus muscles, to anastomose with the anterior radial recurrent artery. In this groove it is covered by the external cutaneous and musculospiral nerves, and still more superficially by the cephalic vein. The posterior branch descends in the substance of the triceps muscle, to which it sends numerous small branches, and terminates in anastomosing with the anterior branch and with the posterior interosseal and ulnar recurrents. The superior profunda artery is often very large, particularly when it arises from the posterior circumflex. The Arteria Nutritia, or nutritious artery of the humerus, arises high up from the brachial, below the superior profunda, and penetrates the oblique canal that may be observed on the inside of the humerus, taking the direction downwards through the compact tissue of the bone, towards the el bow-joint. It supplies the medullary membrane and cancellated structure of the bone, and anastomoses with its other nutritious arteries, which are much smaller, and enter at various points, particularly near the extremities. Professor Harrison relates a case in which an aneurism of this artery ensued on a fracture of the humerus, and amputation was deemed necessary.* The Inferior profunda artery arises nearly opposite the insertion of the coraco-brachialis muscle, and descends on the outside of the ulnar nerve, pierces with it the internal intermuscular ligament, and descends between this ligament and the triceps muscle to the interval between the internal condyle of the humerus and the olecranon process of the ulna, where it is covered by the ulnar nerve, and anastomoses with the posterior ulnar recurrent artery, and with branches from the anastomotic * Surgical Anatomy of the Arteries, p. 180. 186 ULNAR, ARTERY. artery. In this course it supplies the integuments of the arm, and the biceps and triceps muscles. This artery may be small, absent, or double, or may arise in common with the superior profunda. The Anastomotic artery arises from the inside of the brachial, a little above the bend of the elbow : it then descends with a slight degree of obliquity inwards, anastomoses with the anterior ulnar recurrent, pierces the internal intermuscular ligament, and terminates between the internal condyle and olecranon process, in anastomosing with the inferior profunda artery and the posterior ulnar recurrent. The anastomotic artery varies considerably in size, being usually small, but sometimes as large as the inferior profunda. The Muscular branches are distributed in all directions : some go forwards to the biceps muscle, others backwards to the brachialis anticus ; a third set are distributed externally to the coraco-brachialis muscle ; and a fourth internally, extend to the pectoral muscles. At the bend of the elbow, the brachial artery divides into two terminating branches. Professor Harrison refers this division to a point opposite to the coronoid process of the ulna ; and Professor Quain states, that the usual place is a little below the elbow-joint. The terminating branches are the following : — Ulnar Artery. Radial Artery. The Ulnar Artery, larger than the radial, proceeds at first obliquely downwards and inwards beneath the pronator radii teres muscle, the deep head of which separates it from the median nerve ; then, beneath the flexor carpi radialis, palmaris longus, and flexor sublimis digitorum muscles. In this course it lies on the flexor profundus, and is usually accompanied by a filament of communication between the median and the ulnar nerves. In the remainder of its course to the 187 BRANCHES OF THE ULNAR. annular ligament of the carpus, it descends vertically on the flexor profundus muscle, covered by the flexor carpi ulnaris and flexor sublimis, and may be exposed by dividing the fascia and separating these two last mentioned muscles : as it approaches the wrist-joint it is placed between the tendon of the flexor sublimis on its radial side, and the flexor carpi ulnaris on its ulnar side. It is joined at an acute angle by the ulnar nerve at the junction of the superior and middle thirds of the forearm, after which it has this nerve to its ulnar side as far down as the wrist-joint. Finally it gets into the palm of the hand by descending in front of the annular ligament, covered, however, by an aponeurotic slip, connecting the front of that ligament to the pisiform bone. In this situation the nerve lies a little posterior to the artery. The ulnar artery gives off the following branches :— Anterior Ulnar Recurrent. Posterior Ulnar Recurrent. Common Interosseal. Muscular Branches. Anterior Carpal. Posterior Carpal. Communicating Branch or Communicans Profunda. Superficial Palmar. The Anterior Ulnar recurrent is small, and sometimes together with the posterior ulnar recurrent, comes from a single trunk common to them both : it passes obliquely downwards and inwards in the first instance between the pronator teres and brachialis anticus muscles, and then, curving upwards, gains the front of the internal condyle, and anastomoses with the anastomotic branch of the brachial artery. In this course it supplies the brachialis anticus, pronator teres, flexor carpi radialis, and flexor sublimis muscles. The Posterior Ulnar recurrent, much larger than the preceding, descends at first a little inwards, between the flexor profundus digitorum, which lies behind it, and the muscles arising from the internal condyle, which lie in 188 INTEROSSEAL ARTERY. front. It then ascends parallel to the ulnar nerve and between the heads of the flexor carpi ulnaris, to arrive at the interval between the internal condyle and olecranon process ; here it terminates in communicating with the anastomotic, and inferior profunda branch of the brachial, having previously supplied the above mentioned muscles, besides the elbow-joint, ulnar nerve and integuments. The superior radio-ulnar articulation is supplied by a small artery, arteria articularis cubiti media, which, according to Meyer, arises from the brachial, ulnar, or interosseal artery : this small artery passes into the joint and supplies the synovial membrane : he says it is analogous to the posterior articular artery of the kneejoint. The Common Interosseal artery comes off immediately below the recurrents, and descends backwards and outwards to the superior margin of the interosseous ligament, where it divides into the anterior and posterior interosseal arteries. Before its division it gives off a small but pretty constant artery, the comes nervi mediani, which accompanies the median nerve to the wrist, where it terminates : occasionally this artery is of considerable size, and joins the superficial palmar arch : it is sometimes a branch of the ulnar. The Anterior interosseal artery descends on the front of the interosseous ligament, between the flexor pollicis longus and flexor digitorum profundus muscles, being covered and accompanied down the forearm by a branch of the median nerve: in its course down the fore-arm it sends small branches to the muscles in relation to it, and two or three very small perforating arteries which pass through the interosseous ligament and supply the deep-seated muscles on the back of the fore-arm. Having arrived at the pronator quadratus muscle, the anterior interosseal divides into two branches : one supplies this muscle, and terminates in anastomosing with the carpal arteries and the deep COMMUNICANS PROFUNDA. 189 palmar arch ; the other passes backwards through an oval opening in the lower portion of the interosseous ligament, to anastomose with the posterior carpal and posterior interosseal arteries. The Posterior interosseal artery passes downwards and backwards, between the anterior oblique and interosseous ligaments, and, having thus arrived at the posterior superior part of the fore-arm, gives off the interosseal recurrent branch, improperly called the "posterior radial recurrent artery," which ascends between the supinator brevis and anconeus muscles, and then through the fossa between the external condyle of the humerus and the olecranon process : after piercing the triceps muscle it terminates in anastomosing with the superior profunda and posterior ulnar recurrent arteries. After giving off this recurrent branch, the posterior interosseal artery descends on the back of the fore-arm, not lying on the interosseous ligament, but placed between the superficial and deep layer of muscles. In this course it is accompanied by a branch of the musculo-spiral nerve, and gives off numerous branches to the surrounding muscles ; at the wrist the artery becomes very small, and terminates in anastomosing with the anterior interosseal, and the posterior carpal arteries. The Muscular branches pass off from the ulnar artery in its course along the fore-arm, and supply the various muscles with which it is related. The Anterior carpal branch, extremely small, passes horizontally outwards, along the inferior margin of the pronator quadratus muscle, and behind the tendons of the superficial and deep flexors. It anastomoses with the anterior carpal branch of the radial artery. The Posterior carpal branch comes off about an inch and a half above the pisiform bone : it winds round the inferior extremity of the ulna to the back of the carpus, in passing beneath the tendon of the flexor ulnaris muscle : it sends small branches to the little finger, and 190 SUPERFICIAL PALMAR ARCH. terminates by anastomosing with the posterior carpal branch of the radial. After the ulnar artery has arrived in the palm of the hand, it terminates by dividing into the communicans profunda and palmaris superficialis branches. The Communicans profunda should not be dissected till the palmaris superficialis and superficial palmar arch of arteries have been examined. It passes obliquely downwards and inwards, between the pisiform bone and unciform process of the unciform bone, lying superficial to the ligament which connects these bones; it next passes between the origin of the abductor minimi digiti internally, and the origin of the flexor minimi digiti externally; it then turns outwards, beneath the two muscles arising from the unciform process, viz., the short flexor and opponens minimi digiti, to join the palmaris profunda, a branch of the radial, and so to form the deep palmar arch. In this course it is accompanied by a large branch of the ulnar nerve, which lies superficial to it. The Superficial palmar artery is usually much larger than the preceding. It winds downwards and outwards, beneath the palmar aponeurosis, to inosculate with the superficialis volse, a branch of the radial artery ; and thus forms the superficial palmar arch. SUPERFICIAL PALMAR ARCH. The Superficial palmar arch of arteries corresponds nearly to the semicircular fold on the palm of the hand which circumscribes the muscles of the thumb : it is, in general, smaller than the deep arch, and its convexity, which looks downwards and inwards, is nearer to the phalanges : anteriorly it is covered by the integuments and palmar aponeurosis : posteriorly it lies on the flexor tendons, and the divisions of the median nerve as they pass to the fingers. In the fore-arm we see the radial and ulnar arteries lying between their corresponding 191 DIGITAL ARTERIES. nerves ; but in the hand the order is reversed, the nerves being situated between the arches of arteries. The branches of the superficial palmar arch arise both from its concavity and from its convexity. The Branches from the Concavity of the Superficial Palmar Arch are small and numerous : they supply the tendons of the flexor muscles, the lumbricales, lower portion of the median nerve, the annular ligament, and parts in the immediate vicinity; and anastomose with branches of the radial and ulnar arteries. The Branches from the Convexity of the Superficial Palmar Arch are the four digital arteries. The First Digital artery, or the most internal, supplies the ulnar side of the little finger; the second advances to the cleft between the little and ring fingers; the third to the cleft between the middle and ring fingers ; and the fourth to the cleft between the middle and index fingers: each of them then bifurcates to supply the opposed surfaces of the respective fingers. These digital arteries follow the anterior and lateral margins of the fingers, supplying the digital articulations and synovial sheaths, and forming a vascular plexus beneath the nail of each finger. Those of the same finger frequently communicate both in its anterior and posterior regions, and opposite the ungual phalanx meet in the form of an arch, the concavity of which looks towards the hand, and from the convexity of which are sent off numerous minute vessels to supply the extremities of the fingers. The digital nerves are superficial, that is, anterior to the arteries ; the latter either pierce or cross the nerves in order to obtain this position. It is of importance to know the precise spot at which the bifurcation of the second, third, and forth digital arteries takes place, in order that the surgeon may avoid wounding these arteries when making the necessary incisions into the palm of the hand, for the purpose of giving exit to matter in this locality. If we examine the palm 192 LIGATURE OF THE ULNAR ARTERY. of the hand we will find a fold or crease running somewhat transversely from one side to the other, and corresponding to the palmar surface of the metacarpo-phalangeal articulations of the four fingers. If we measure from this fold forwards to the lunated margin of each of the three webs between the fingers, we will find the distance of each to be from about an inch and quarter to an inch and half : the bifurcation of each of the digital arteries will be found to correspond to about the central point between the fold and the anterior or lunated border of the web. Operation of tying the Ulnar Artery. —If the ulnar artery be wounded in its superior third, we may either adopt the method recommended by Mr. Guthrie, and cut down through the mass of muscles which covers it, taking care to avoid the median nerve ; or we may tie the brachial artery in its inferior third : the latter proceeding, in conjunction with the employment of graduated compresses and bandages to the part of the limb below this, is to be preferred. If the upper part of the ulnar artery be affected with aneurism, tying the brachial is the only proper course. If it be necessary to tie the ulnar artery lower down, as in cases of wounds, it will be readily found by cutting on the interval between the flexor sublimis digitorum and flexor carpi ulnaris. The fascia should be divided on a director, and the needle carried round the vessel from within outwards, taking care to avoid the nerve which lies to its ulnar side, and the venae comites which lie one on either side. Wounds of the palmar arch generally bleed profusely. If a spouting vessel present itself, it may be seized with the tenaculum, and secured in a ligature. This practice, however, is seldom available, as the blood generally flows from a number of orifices, which are by no means distinct. In such case the surgeon should close the wound, and employ a bandage with graduated compresses ; or, 193 RADIAL ARTERY. if this should fail, he may introduce into it a bit of sponge, covered with gauze to prevent the lymph effused from lodging in its cells, and then apply the bandage and compresses as before : this, with the temporary application of the tourniquet to the brachial artery, or the application of compresses placed on the ulnar and radial arteries, will usually be sufficient even in severe cases. Sometimes, however, it may be necessary to tie one or both arteries of the fore-arm : even after this the hemorrhage has continued, and in an instance of the kind, Mr. Adams has succeeded in restraining the bleeding by the application of a compress and bandage over the back of the wrist, so as to exercise pressure on the dorsal carpal arteries. If the wound be towards the radial side, we should tie the radial first ; and if on the ulnar side, the ulnar artery should be first secured. It should be recollected, that sometimes the artery accompanying the median nerve, and the anterior interosseal artery, are particularly large, and terminate in the superficial or deep arch. The Radial Artery, smaller than the ulnar, but more in the direction of the brachial artery, descends towards the wrist, being related posteriorly, from above downwards, to the tendon of the biceps, the insertion of the supinator brevis, the pronator teres, the radial origin of the flexor sublimis, the flexor pollicis longus, and the pronator quadratus muscles : externally it is related to the supinator longus muscle, which overlaps it a little ; and internally to the pronator teres above, and flexor carpi radialis lower down. Anteriorly it is covered only by fascia, integuments, and the approximation of the muscles at either side. Thus in the upper part of its course the artery will be found between the supinator longus and pronator teres, whilst below this it lies between the supinator radii longus and flexor carpi radialis. The radial artery is accompanied by two veins, the vence o 194 RADTAL ARTSRY. comites, and in the two superior thirds of the fore-arm by the radial branch of the musculo-spiral nerve, which lies to its outer or radial side : below this point the nerve forsakes the artery and winds round the outside of the radius, passing underneath the tendon of the supinator radii longus, in order to arrive at the outer side of the posterior part of the fore-arm. At the lower extremity of the fore-arm the artery turns round the external lateral ligament of the wrist-joint, being parallel to the radial extensor Fig. 24.— Represents the Deep Arteries of the upper Extremity. A, A, Brachial Artery. B, B, Radial Artery. C, C Ulnar Artery. 1>, 1>, Anterior Interosseal Arteiy. K, Slender twig to the Brachialis Anticus. P, Deep Palmar arch of Arteries formed by the Communicans Profunda of the Ulnar, and Palmaris Profunda of the Radial Arteries. Q, Portion of First Dorsal Interosseous Muscle. 1. Coraco-brachialis Muscle. 2, Long portion of Triceps Muscle. 3, Brachialis Anticus. 4, Internal Intermuscular Septum. 5, Short portion of Triceps Muscle. 6, Extensor Carpi Radialis Longus. 7, Twig to the Brachialis Anticus. 8, Part ot the origin of Pronator Radii Teres. 9, Origins of Flexor Carpi Radialis and Palmaris Longus. 10, Extensor Carpi Radialis Brevis Muscle. 11, Supinator Radii Brevis Muscle. 12, Portion of the Flexor Profundus Muscle. 13. Insertion of Pronator Teres cut. 14, 15, Flexor Pollicis Longus having the Radial Artery passing over it. 16, 16, 16, The Interosseous Ligament with Anterior Interosseal Artery. 17, Pronator Quadratus with branch of Interosseal Arteiy. 18, Anastomosis between Anterior Interosseal, the Deep Palmar Arch, and the Anterior Carpal Arteries. 19, 20, Abductor Minimi Digiti Muscle. 21, 21, 21, Palmar Interossei Muscles, a, Muscular Branch, c, Superior Profunda Artery, d, Inferior Profunda Artery, e, f, g, h, Muscular branches to Triceps and Brachialis Anticus Muscles. i, Anastomotic Arteiy. 1, Radial Recurrent Artery, m, Superficialis Voire cut. n, Princcps Pollicis Artery, o. Anterior Ulnar Recurrent Artery ascending to anastomose with the Anastomotic artery, r, r, r, Digital Arteries, s, s, 8, Cut ends of the Digital Arteries of the Superficial Palmar Arch, t, t, t, t, u, u, u, u, v, v, v, v, Anastomoses between the Digital Arteries. RADIAL ARTERY 195 muscles, and covered by the extensor muscles of the thumb. Here it pierces the abductor indicis manus muscle, and terminates, in crossing the palm of the hand, under the name of the palmaris profunda. As the artery is passing obliquely across the back of the outer portion of the wrist, it will be found lodged in a triangular space, the base of which corresponds to the back part of the lower extremity of the radius ; the apex is situated at the metacarpal bone of the thumb; one side is formed by the extensor secundi internodii pollicis and extensor carpi radialis longus ; and the other, or radial side, is formed by the tendon of the extensor primi internodii pollicis. Immediately underneath the integuments covering this hollow space, we find Fig. 25.— Represents the arterirs of the posterior part of the upper extremity which are seen after the removal of the skin and aponeurosis. 1, Deltoid Muscle. 2, Triceps Extensor Cubiti. 3, Biceps Flexor Cubiti. 4, Brachialis Amicus. 5, Supinator Longus. 6, Extensor Carpi Badialis Longus. 7, Extensor Carpi Radialis Brevis. 8, ExtensorCommunis Digitorum. 9, Extensor Carpi Ulnaris. 10, Anconeus Muscle. 11, Flexor Carpi Ulnaris. 12, Extensor Ossis Metacarpi Pollicis. 13, Extensor Primi Internodii Pollicis. a, a, a, Muscular branches of the Superior Profunda, b. Branch of the Superior Profunda, c, o, Anastomoses between the Superior Profunda and Twigs from the Interosseal and Posterior Ulnar Recurrent Arteries, d, Twig from the Radial Recurrent Artery, e. Twigs from the Interosseal Artery, f, Twig from the Interosseal Artery, g, h, Arterial Anastomosis, i, Radial Artery k, k, k, k, Twigs from the Anterior Digital Arteries to the backs of the Augers. o 2 196 BRANCHES OF THE RADIAL. the origin of the radial vein and some branches of the radial division of the musculo-spiral nerve. The branches of the radial artery are the following:— Radial Recurrent. Muscular. Superficialis Volae. Anterior Carpal. Posterior Carpal. Dorsalis Pollicis. Metacarpal. Radialis Indicis. Princeps Pollicis. Palmaris Profunda. The Radial recurrent. This branch, which arises high up in the fore-arm, proceeds at first in a curved direction outwards, the convexity of the curve looking downwards and lying below the radio-humeral articulation: it then ascends on the front of the supinator brevis, in the groove between the supinator longus and brachialis anticus, where it anastomoses with the superior profunda artery : from the convexity of its arch it sends many branches downwards to be lost in the supinator brevis and supinator longus muscles, and in the upper extremities of the extensor muscles. The Muscular branches. In its course down the forearm, the radial artery sends branches to the adjacent muscles, and through the aponeurosis to the integuments. The Superficialis Voke. This is usually a small branch; sometimes however it is very considerable. It descends on the front of the annular ligament of the wrist ; then over, or through the origins of the small muscles belonging to the thumb. It next turns inwards, beneath the palmar aponeurosis, and by anastomosing with the superficial palmar branch of the ulnar artery, contributes to form the superficial palmar arch already described. The Anterior Carpal artery is small but constant. It runs transversely inwards, along the inferior margin of the pronator quadratus, to anastomose with a similar branch from the ulnar. The Posterior Carpal artery is very much larger than the anterior. Its origin corresponds to the outer edge of BRANCHES OF THE RADIAL. 197 the extensor carpi radialis longus muscle, and is nearly opposite the interval between the first and second range of carpal bones. It passes almost horizontally inwards, lying on the second row of carpal bones, covered by the radial extensors and the extensors of the fingers, to anastomose with the posterior carpal branch of the ulnar artery: its superior branches are distributed to the wrist-joint, and communicate with the anterior interosseal: its inferior branches are the second, third, and fourth perforating arteries, each of which sinks between the heads of the corresponding dorsal interosseous muscle, to join the deep palmar arch : the trunk of the radial artery may be considered the first perforating artery, as it pierces the first interosseous muscle, or abductor indicis manus, in a similar manner. Before these arteries 1, Humerus. 2, Brachialis Anticus. 3, Origins of Supinator liatlii Longus and Extensor Carpi Radialis Longus Muscles. 4, i'ortion of Insertion of Triceps. 5, External Lateral Ligament of the Elbow-joint. 6, 6, Interosseous Ligament of the Forearm. 7, Ulna. 8. Kadius. a, a, Superior Profunda Artery, b. Radial Recurrent Artery, c, c, Anastomoses between the Superior Profunda, the Radial Recurrent, and Interosseal Recurrent Arteries. d, Posterior Interosseal Artery, after passing backwards between the Oblique and Interosseous Ligaments, divided, e, f, f, f, g, Perforating brandies from the Anterior Interosseal Artery, h, Twig to Carpus, i, Radial Artery, k, k, k, Dorsal Carpal Twigs. 1, Dorsal Artery of Thumb, m, Internal Dorsal Artery of Thumb, n, Continuation of the Princeps Pollicis Artery, o, Iladialis Indicis Artery, p, Posterior Carpal branch of Ulnar Arteiy. q. Branch of Posterior Ulnar Carual Artery to the little finger, r, r, r, Perforating Twigs of the Palmar Interosseal Arteries, s, s, s, Dorsal or Posterior Interosseal Arteries of hand, t, Radial Arteiy passing into the palm of the hand, u, v, w, x, y, z, Small branches to the sides of the Dorsal aspect of the 1st, 2nd, 3rd, and 4th fingers. Fig. 26.— Represents the deep arteries of the posterior part of the upper extremity. 198 BRANCHES OF THE RADIAL. pierce the muscles, they send off interosseal branches, which descend between the interosseous muscles and integuments, and occasionally pierce the lower part of the interosseous space, to join the digital branches of the palmar arch. The Dorsalis Pollicis. Before the radial artery sinks between the two first metacarpal bones, it gives a branch or branches to the posterior surface of the metacarpal bone of the thumb ; it also frequently gives off a slender branch that descends on the cutaneous surface of the abductor indicis manus. The Metacarpal artery, or dorsalis indicis is very variable in size, being sometimes diminutive, and at other times extremely large. Sometimes it seems to be a continuation of the radial. It descends over the metacarpal bone of the index finger, and sinks between the second and third metacarpal bones, to join the digital branch of the superficial palmar arch that supplies the adjacent sides of the index and middle fingers. The Radialis Indicis descends between the abductor indicis and adductor pollicis : it then follows the external margin of the index finger, and, at its extremity, anastomoses with the internal digital branch of the same finger. The Princeps Pollicis, or digital artery of the thumb, descends between the abductor indicis and deep head of the short flexor pollicis. It then follows the internal margin of the thumb, and anastomoses with the other small digital vessels which run along the dorsal aspect of the thumb. In some cases the radialis indicis and princeps pollicis arise by a common trunk, which descends to the lower part of the first interosseous space before it bifurcates : this is described as the regular disposition by Cloquet and Boyer. Professor Harrison describes the radial artery as terminating by dividing into three branches ; the radialis indicis, princeps pollicis, and palmaris profunda. The Palmaris Profunda. This is the proper termina- 199 DEEP PALMAR ARCH. tion of the radial artery ; it passes horizontally inwards, between the metacarpal bones and interosseous muscles which are behind it, and the adductor pollicis and flexor tendons which lie in front. It then unites with the deep terminating branch of the ulnar, thus forming the deep palmar arch. DEEP PALMAR ARCH. The Deep palmar arch of arteries is covered in front by all the nerves, tendons, and muscles of the palm of the hand, except by the interosseous muscles, which, together with the metacarpal bones, lie behind it. It crosses these bones nearly at right angles, lying close to their carpal extremities, and forming a slight curvature, the convexity of which looks towards the phalanges. This arch is accompanied by a branch of the ulnar nerve, which passed in company with the communicans profunda branch of the ulnar artery into this deep-seated situation of the hand: the nerve lies on the anterior surface of the arch and terminates in the muscles of the thumb. The deep palmar arch gives off the following branches : Anterior. Posterior. Superior. Inferior. The anterior branches are small, and are lost in the lumbricales muscles. The posterior branches, three in number, pass backwards towards the second, third, and fourth interosseous spaces : each of them penetrates between the two origins of the corresponding dorsal interosseous muscle, to communicate with the posterior carpal artery: these arteries may therefore be indifferently considered as branches of the last-mentioned artery, or of the deep arch. The superior branches are small, and are lost on the carpus. The inferior branches, three or four in number, descend 200 DESCENDING AORTA. along the interosseous spaces, and anastomose with the digital branches of the superficial palmar arch. Operation of tying the Radial A rtery. The radial artery may be tied in the upper part of the fore-arm by making an incision over the interval between the pronator radii teres and supinator longus. In the lower part of the fore-arm it will be found between the flexor carpi radialis and supinator longus. In either case, after making the incision through the integuments, the fascia should be divided on a director: a small vein will be found on either side of the artery, and the radial nerve will lie on its external side. The possibility of mistaking the superficialis volee for the trunk of the radial should be borne in mind. In judging of the strength of the pulse at the wrist, it will be necessary to attend to the deviations in the course and size of the radial artery. Sir Philip Crampton succeeeded in curing a circumscribed traumatic aneurism of the radial artery as it passes behind the wrist, by the application of Dr. Carte's compressing instrument upon the artery leading to the tumor. * THE DESCENDING AORTA. This large vessel is a continuation of the arch of the aorta, and may be described as commencing opposite the lower part of the body of the third dorsal vertebra, and terminating opposite the fourth lumbar. Its commencement and termination are both on the left side of the spine, but that part of it which passes between the crura of the diaphragm approaches the middle line, so that in its entire course it forms a lateral curvature, the convexity of which is turned to the right side. In this respect the artery accommodates itself to the natural lateral curve which exists in the dorsal portion of the spine, the convexity of which is also directed towards the right side ; in * Dub. Med. Press, vol. xxii. p. 61. DESCENDING AORTA. 201 addition to this the artery follows the curvature of the spine in the antero-posterior direction, and is therefore Fig. 27.— The Thoracic Aorta and its Branches. A, Ascending portion of the Arch of the Aorta. B, Middle portion of the Arch. C, Termination of the descending portion of the Arch. 1), Thoracic Aorta. E, Arteria Innominata, or Brachio-Cephalic Artery. F, Kight Common Carotid Artery. G, Kight Subclavian Artery. H, Left Common Carotid Artery, I, Left Subclavian Artery. K, K, Inferior Phrenic or Diaphragmatic Arteries, which in this case came abnormally from the Cceliac Axis, a, a, a, Sigmoid or Semilunar Valves of the Aorta, b, Origin of the right Coronary Artery, c. Origin of the Left Coronary Artery, d. Bight Bronchial Artery, in this case arising from the concavity of the Arch of the Aorta, e. Left Bronchial Artery, having a similar origin, f, f, Oesophageal Arteries, g, g, g, g, g, g, Left Inferior or Aortic Intercostal Arteries. h,h, h,h, h, h, Kight Inferior or Aortic Intercostal Arteries. 1, Trachea. 2, Right Bronchus. 3, CSsophagus. 4,4, Portion of the Diaphragm. 202 THORACIC AORTA. concave forwards in the thoracic region, and convex forwards in the abdominal. The descending aorta is divided into two portions, viz. the thoracic aorta, and the abdominal aorta. We shall first examine the thoracic, and then the abdominal portion. THE THORACIC AORTA. This great division of the descending aorta may be said to commence opposite the third dorsal vertebra, and to terminate in passing between the pillars of the diaphragm. As far as the tenth dorsal vertebra it is situated in a region called the posterior mediastinum: this region approaches somewhat to the form of a prism, and extends from about the third to the tenth dorsal vertebra: its sides are formed by the two pleurae ; its apex is situated anteriorly and corresponds to the back part of the pericardium, and its base is formed by the bodies of the vertebrae from the third to the tenth. The direction of the thoracic aorta is downwards, forwards, and to the right side. Its posterior surface rests on the spine and demi-azygos vein, and usually on the third, fourth, and fifth intercostal veins of the left side : the intercostal arteries arise from this part of the vessel. Its anterior surface is covered by the root of the left lung, by the back of the pericardium, and lower down by the oesophagus with the vagi nerves, and by the decussating muscular bands which spring from and connect the pillars of the diaphragm. Its left side is closely related to the left pleura and lung. Its right side is related remotely to the right lung and pleura, to the thoracic duct and vena azygos, and inferiorly it is related to the right crus of the diaphragm, from which it is separated by the vena azygos and thoracic duct. Along its right side superiorly we may also observe the oesophagus passing downwards towards the stomach : if we examine the relations between the oesophagus and aorta we will find that these tubes run somewhat spirally with 203 BRONCHIAL ARTERIES. regard to one another : at first the oesophagus lies upon a plane posterior to the second or middle portion of the arch of the aorta, though not in immediate relation to it; it then lies to the right side of the third portion of the arch, and continues its course along the right side of the thoracic aorta until it reaches a point corresponding to about the body of the seventh dorsal vertebra ; the oesophagus here begins to pass obliquely from right to left, across the front of the aorta, and finally at its termination in the stomach, it lies to the left side of this vessel, and upon a plane considerably anterior to it. The right and left splanchnic nerves descend on either side of it, the left being nearer to the artery. The branches of the thoracic aorta are the following : Pericardial. Bronchial. (Esophageal. Posterior Mediastinal. Inferior Intercostal. The Pericardial branches are a few small and irregular arteries which arise from the front of the vessel and are distributed to the back part of the pericardium. The Bronchial arteries arise from the anterior part of the aorta ; they are amongst the most irregular in the body, and can only be recognized by their termination in the lung, and not by their origin, as they may arise from the aorta, the intercostals, the mammary, or even from the subclavian arteries. Those most constantly found, are three in number; viz., one on the right side; and two on the left, —a superior and an inferior. The right bronchial artery sometimes comes from the aorta, in common with the left, or separately: usually, however, it is a branch of the first aortic intercostal: in all cases it descends on the back of the right bronchus, and, winding round it, accompanies it into the lung: the superior left bronchial artery usually comes from the aorta, and, in a similar manner twines round the left bronchus, and with it enters the lung: the left inferior bronchial artery 204 INTERCOSTAL ARTERIES. often arises from the aorta, opposite the third or fourth dorsal vertebra, and is conducted to the left lung by the left superior pulmonic vein: it is not as constant as the two preceding. Arrived at the lung, the right bronchial artery usually divides into five branches, and the left into four : these subdivide, and accompany the divisions of the bronchi through the lung, in such a manner, however, that one division of the bronchus has usually with it two or three arterial branches, which, frequently anastomosing, form a delicate net-work round the air-vessel. The bronchial arteries communicate with the other blood vessels of the lung. Two or three other bronchial arteries may arise occasionally from the concavity of the arch of the aorta, and also repair to the lung. The (Esophageal arteries, three to six in number, arise from the anterior part of the thoracic aorta, at variable points : they are lost in the tunics of the oesophagus, and in anastomosing with the inferior branches of the inferior thyroid artery and with the oesophageal branches of the gastric artery. They are always very small, and the highest of them occasionally comes from one of the bronchial arteries. The Posterior Mediastinal branches are small and numerous, they arise from various parts of the thoracic aorta, and supply the glandular structures and areolar tissue contained in the posterior mediastinum. The Inferior or Aortic Intercostals are usually from nine to ten in number on each side, according as the superior intercostal gives off three or two branches : they all arise from the posterior and lateral part of the thoracic aorta. The superior run obliquely upwards and outwards, the middle less obliquely outwards, and the inferior almost transversely: those of the right side, having to cross the spine, are necessarily longer than those on the left, and have additional relations : from their origins to the angles of the ribs, they rest on the spine posteriorly, and are covered INTERCOSTAL ARTERIES. 205 in front by the oesophagus, thoracic duct, vena azygos, sympathetic nerve, and the right pleura. Those of the left side, traced as far as the heads of the ribs, rest on a very small portion of the spine, and are only covered by the sympathetic nerve and left pleura. In the remainder of their course, being exactly alike on right and left, the same description will serve for the intercostal arteries of both sides. There are some differences, however, between the relations of those above and those below : thus, the superior aortic intercostal communicates with the lowest intercostal branch from the subclavian, while each of the others communicates with the aortic intercostal above and below it: again, those low down cross behind the splanchnic nerves on both sides, and behind the demi-azygos vein on the left side ; and the eleventh and twelfth intercostals on either side pass behind the corresponding pillar of the diaphragm. Having arrived in the intercostal space, each of the intercostal arteries divides into an anterior and posterior branch : the anterior branch, larger than the posterior, proceeds outwards towards the angle of the rib, having in front of it the pleura, and behind it the anterior, or inferior costo-transverse ligament, and the external layer of intercostal muscles; having arrived near the angle of the rib, it divides into a superior and inferior branch, both of which sink between the two layers of intercostal muscles: the inferior, much the smaller, runs for a short distance along the superior margin of the rib below, and is then lost in the periosteum on its external surface ; while the superior, which is really the continued anterior intercostal, runs forwards between the two layers of intercostal muscles, lodged in the groove in the inferior margin of the rib above, till it reaches the anterior part of the thorax ; its corresponding vein lying above it and its nerve beneath it; here it descends in the intercostal space, and its mode of termination depends on its situation: those corresponding to the true ribs anastomose with the inter- 206 ABDOMINAL AORTA. nal mammary artery; those corresponding to the false ribs sink into the abdominal muscles, and, having supplied them, anastomose with the mammary, epigastric and circumflexse ilii arteries. The twelfth anterior intercostal differs somewhat from the preceding ; it runs downwards and outwards, between the corresponding crus of the diaphragm and the body of the last dorsal vertebra; then along the inferior margin of the twelfth rib, opposite to the middle of which it divides into transverse and descending branches; these are lost in the broad muscles of the abdomen, and in communication with the lumbar and circumflexse ilii vessels. The posterior branch of each intercostal artery passes backwards, between the body of the corresponding vertebra on the inside, and the inferior costo-transverse ligament on the outside : in this situation it sends a small branch through the lateral foramen of the spine to the tunics of the spinal marrow, and then continues its course backwards to be lost in the spinotransverse, longissimus dorsi, and sacro-lumbalis muscles; some of its branches extend to the latissimus dorsi and trapezius muscles, and are lost in the integuments. THE ABDOMINAL AORTA. The examination of this vessel may be deferred till its branches have been dissected. It is about five inches and a half or six inches in length, and extends from the aortic opening in the diaphragm, to the left side of the fourth lumbar vertebra, or to the cartilage between the fourth and fifth : it may, however, extend to the fifth, or only as far as the second. The aortic opening in the diaphragm is oblique, and corresponds to the twelfth dorsal and part of the first lumbar vertebrae : its sides are formed by the two crura of the diaphragm ; anteriorly and superiorly it is bounded by a tendinous arch which unites the two crura across the anterior aspect of the artery, and from the convexity of which arch some of 207 LIGATURE OF THE AORTA. the short fleshy fibres of the crura arise ; and posteriorly by the anterior common ligament of the spine, which separates the vessel from the first lumbar vertebra. The posterior surface of the abdominal aorta rests on the spine, right crus of the diaphragm, which here sends an expansion in front of the lumbar vertebrae ; on the receptaculum chyli, and left lumbar veins : the lumbar and middle sacral arteries arise from this surface of the vessel and are therefore placed posterior to it. The anterior surface is covered from above downwards, first by the posterior edge of the liver, next by the union of the semilunar ganglia to form the solar plexus ; by the aortic plexus of nerves, by the lesser omentum and stomach, then by the commencement of the vena portae and superior mesenteric artery, both of which separate it from the pancreas, which also crosses the anterior surface of the vessel ; lower down, it is covered by the left renal vein, which separates it from the third portion of the duodenum ; this intestine crosses the artery at a point corresponding to about the third lumbar vertebra : still lower, it is crossed by the transverse mesocolon and mesentery, and inferiorly by a single layer of the peritoneum, namely, the continuation downwards of the inferior or descending layer of the mesentery. Its left side corresponds to the left pillar of the diaphragm above, and below to the peritoneum. Its right side is separated from the vena cava superiorly, by the Spigelian lobe of the liver, the right crus of the diaphragm, the vena azygos, and the thoracic duct ; lower down it is nearly in contact with the latter vein. The sympathetic nerves also lie one at each side of the aorta, the left being in closer relation to it, and both on a plane posterior to the vessel. Operation of tying the Aorta. —The abdominal aorta has been tied five times in the human subject, but unfortunately in every case without success. Sir A. * Med. Ch. Trans, vol. ii. p. 158. 208 LIGATURE Of THE AORTA. Cooper was led, by a number of experiments* which he performed on dogs, and by a consideration of the various cases on record, in which the aorta had been found obliterated after death, to believe in the possibility of tying this vessel in the human subject, with safety and advantage. It is true that in every instance in which it was found impervious in the human subject, the effect was produced slowly, and the anastomosing branches were gradually prepared for the additional duty they were to perform ; yet it does not appear, either from experiments on brutes, from which, however, conclusions should be drawn with great caution, or from the results of the cases in which it has been tied in man, that the operation must fail, either on account of the immediate shock given to the system, or of the diminished supply of blood sent to both the lower extremities. Sir A. Cooper says he has ascertained that if the aortic plexus be tied with the artery, the lower extremities are rendered paralytic and the animal dies; but these consequences do not occur if the plexus be not included in the ligature. LIGATURE OF THE AORTA. No. Operator. Date of Operation Results and Observations. 1 Cooper ... 1817 Death on 2nd day after the operation. 2 James ... 1829 Death on the evening of the day on which the operation was performed. 3 Murray... 1834 Death in twenty-three hours. 4 Monteiro 1842 Death, from hemorrhage, on 10th day after operation. 5 South ... 1856 Death in forty-two hours. Sir A. Cooper's Case. —A patient in Guy's Hospital had violent bleeding just above the left groin, from an aneurismal tumour of the external iliac artery. The MR. JAMES' CASE. 209 integuments had sloughed, and the patient was exceedingly reduced from loss of blood. Under these circumstances, and finding it impossible from the size of the tumour to secure the iliac artery, Sir A. Cooper felt justified in tying the aorta. The operation was performed in April, 1817. He made an incision into the linea alba three inches long, allowing a curve in it to avoid the umbilicus. In this manner the sac of the peritoneum was opened, and the fingers were then conveyed to the artery, which was readily distinguished by its strong pulsations. The peritoneum was then lacerated with the finger nail, in order to allow the ligature to be conveyed around it at about three quarters of an inch above its bifurcation. During the operation the faeces were involuntarily discharged. The patient died on the second day after the operation, and his death is ascribed by Sir A. Cooper to want of circulation in the aneurismal limb ; which led him to observe that "in an aneurism similarly situated, the ligature must be applied before the swelling has acquired any very considerable magnitude."* In his Surgical Lectures he observes, " If I were to perform this operation again, the only difference that I would make, would be to cut the ligature close to the vessel, where it might take its chance either to be encysted or absorbed." A little farther on he observes, —"The principal danger appeared to arise from the irritation produced in the intestines by the ligature ; and that is the reason why I would cut the ligature close to the vessel." In dissection there were no appearances of peritoneal inflammation. Mr. James' Case. — "The patient, aet. 44, of spare habit, but not otherwise unhealthy, had an aneurism of the external iliac artery, of such extent as to prevent any chance of success from tying the iliac artery above the tumour. It was accordingly determined to tie the * Surgical Essays, vol. i. p. 114. P 210 dr. Murray's case. femoral artery on the distal side of the aneurism, according to Brasdor's plan. This operation was performed on June 2, 1829. The patient appeared to be going on well until the 12th, after which the tumour gradually increased ; and on the 24th the integuments were tense and shining, and there was considerable pain."* Mr. James accordingly felt it his duty to give his patient the only remaining chance, by putting a ligature round the aorta. The operation was accordingly performed, on the 5th of July, in the manner practised by Sir A. Cooper. We shall find, farther on, that the aorta may in general be tied without wounding the peritoneum : but in this case it would have been impracticable, as the serous membrane adhered firmly to the anterior surface of the tumour. The patient died on the evening of the day on which the operation was performed; and on opening the body a remarkable anomaly was observed ; the external iliac artery divided, above Poupart's ligament, into two branches ; one of which gave off the epigastric, and afterwards represented the profunda, while the other took the course of the femoral artery. Dr. Murray's Case. —A Portuguese sailor applied at the Civil Hospital, at the Cape of Good Hope, with a large aneurismal tumour over the site of the external iliac artery. " The tumour now presents the greatest size and prominence immediately above Poupart's ligament, in the site of the external iliac artery. The most prominent part is tense, shining, and circumscribed, about the size of an orange, and its hard irregular base extends upwards to an imaginary line drawn from the umbilicus to the lower ribs, and downwards to a couple of inches below Poupart's ligament ; its lateral boundaries being formed by the ilium and linea alba. Pulsation is felt in the prominent part of the tumour, and a sort of whizzing * Med. Ch. Trans, vol. xvi. p. 1. dr. Murray's case. 211 sound is indistinctly discovered in it on the application of the ear or stethoscope ; but there appears to be no circulation in the femoral artery. He does not complain of much pain in the tumour at present, but says it is often excruciatingly severe along the thigh bone, and in the knee. The limb is much swollen, and he keeps it constantly in the bent position, and cannot bear to have it extended. The skin is nearly insensible to the touch, and even to pinching, particularly on the inner part of the thigh ; yet he describes having a feeling as if worms and flies were creeping over it. Temperature of the diseased limb 92 degrees, and of the sound one 97. Pulse 96, and intermittent; and the action of the heart has a corresponding irregularity. Two or three days ago he had an attack of epistaxis. Tongue covered, respiration natural; intellect clear. Has had scarcely any sleep for many nights, and no motion in his bowels for eleven days." He was accordingly taken into the Hospital, and medicines calculated to palliate his symptoms were exhibited. After a few days, however, matters were getting manifestly worse. His features were shrunk, and exsanguine, limb cold and insensible, and the tumour enlarging and assuming a dark bluish appearance at its prominent part. He complained that the friction employed to preserve the temperature of the limb was only increasing his pain, and the greatest agony was felt in the thigh and knee. Under these circumstances it was resolved no longer to defer the operation. "The Operation had to be performed by candle-light, and, moreover, as he lay in bed, that he might not be put to the pain of being moved before and after it. "The size and position of the tumour precluding the possibility of reaching the aorta by cutting from the right side of the abdomen, rendered this necessary to be done from the left, which fortunately, at the same time, had the advantage of affording the readiest and easiest p 2 dr. Murray's case. 212 access to the vessel, on account of its anatomical situation, but greatly increased the difficulty of reaching the right common iliac, to tie it, which it was hoped might be found possible. " The patient lying inclined to the right side, the first incision was commenced a little in front of the projecting end of the tenth rib, and carried for more than six inches downwards, in a curvilinear direction, to a point an inch in front of the superior anterior spinous process of the ilium, its convexity being towards the spine. The skin, the subcutaneous cellular tissue, and the aponeurosis of the external oblique muscle, were first incised ; next the fibres of this muscle ; and successively afterwards the layers of the internal oblique and transversalis muscles were displayed and divided ; which was found rather a delicate part of the operation, as their fibres contracted spasmodically when touched by the scalpel. The fascia transversalis was now brought beautifully into view, and cautiously divided by a pair of scissors upon a director, to avoid wounding the peritoneum. This membrane being now completely laid bare to nearly the whole extent of the external wounds, was next detached from the fascia covering the iliacus internus, and psose muscles, chiefly by the hand, introduced flat between these parts, to separate the loose cellular substance connecting them, which was easily effected. "Whilst detaching the peritoneum in the fossa of the psoas, I found my fingers get into a soft pulpy mass, and a good deal of dark bloody fluid began to ooze out by the side of my hand, which made me withdraw it and examine the parts, by throwing a ray of candle-light into the bottom of the wound, when, from the dark appearance of the parts, my first impression was that they were in a gangrenous state ; but I soon discovered that it was caused by ecchymosis, or effusion of bloody serum into the loose cellular texture. I then re-introduced my hand, and gradually prosecuted the detaching dr. Murray's case. 213 of the peritoneum in the direction of the spine, till I came to a large pulsating vessel, which I found to be the upper part of the left common iliac, and in another minute the aorta itself was under my finger ; to satisfy myself of which, I requested one of the gentlemen assisting me to place his ear on the tumour, and his hand on the left femoral artery, when he heard and felt the pulsation to stop and recommence in each, as I compressed the vessel, or the contrary. I now endeavoured to reach the right common iliac, but found that the walls of the tumour extended nearly close up to the bifurcation of the aorta ; and even had this obstacle not existed, I do not think there is scope for the hand to perform the necessary manipulations to place a ligature upon that vessel from the left side, without using a degree of force, and causing a laceration of parts, that would be inconsistent with due professional caution, humanity, and judgment. " A tedious and rather difficult part of the operation succeeded ; viz., the making a division in the aortic plexus of nerves, and in the membranous sheath covering the aorta, to get betwixt the vessel and the spine, which I effected partly by the steel end of an elevator cranii, but chiefly by my nails, with my mind at my fingers' ends ; and I was not a little rejoiced when I had got a sufficient separation, to be able to insert the point of the aneurism needle beyond and behind it ; after which I was soon able to get it, with the ligature, round the vessel, without including any portion of nerve or other extraneous substance. In this manoeuvre, it was with difficulty that the longest-handled aneurism needle could be made to reach the necessary depth. The ends of the ligatures being brought out, the aorta was gently raised upon it, which enabled us, by holding up the peritoneal bag, to see this great vessel pulsating at an awful rate. "The noose of the ligature was then gradually tightened till all pulsation and circulation was found to have deci- dk. Murray's case. 214 dedly ceased in the left groin ; and we anxiously watched the general effect upon the patient whilst this and the second knot were being tied. " The pulse at the wrist, during the time, underwent no sensible alteration either in strength, fulness, or frequency ; nor did the vascular organization of the head seem to be abnormally congested or excited by the sudden check to this great stream of the circulation. The tightening of the knot did not seem to occasion him any great pain, nor to cause any unusual sensation or shock in the vascular, nervous, or respiratory systems. His first complaint was, that his left leg had become as benumbed and useless as his right, and that we had done him bad service in laming his good leg, which he did not expect, and lamented it bitterly : on feeling the aorta, it was found to be full, and pulsating with very great strength, above the ligature, but empty and motionless below it. The ends of the ligature were now brought out exteriorly, and the lips of the wound drawn together by three sutures and adhesive straps, over which a compress and bandage were applied. " The operation was more tedions than difficult ; and being effected chiefly out of sight by the hand, it had not the terrific appearance which that by the method of cutting into the cavity of the abdomen must have, and it was accomplished with the loss of less than two ounces of blood. At one time, during its performance, he required to get some brandy and water to support him ; but when it was over, he seemed quite as well as before its commencement ; and the pulse was 128, steady and regular. After the operation he felt deadness of the left thigh and leg, and complained of painful distention of the bladder, though it was empty. Afterwards he became easier, and smoked a cigar, and slept a little at intervals. Soon, however, he began to complain of violent pain in the pubic region and loins. Tongue was now dry and dark, DR. MONTEIRO's CASE. 215 strong pulsation of the carotid, and feeble pulse at the wrist, followed by jactitation : cold clammy sweats. No natural warmth ever returned to the lower limbs, and he died twenty-three hours after the operation. On dissection, it was found that the artery had been secured opposite the interval between the fourth and fifth lumbar vertebras ; no extraneous substance was included, and '' the aortic plexus of nerves had been accurately divided." Specks of ulceration were observed on the mucous membrane of the bladder. The vessels of the lower part of the body having been injected, a few drops of the size injection were found in a small anastomosing vessel, discovered passing between the inferior mesenteric artery and left internal iliac ; it arose about two and a half inches below the origin of the mesenteric artery, (from the hemorrhoidal branch of it, which seemed larger than usual,) and joined one of the upper branches of the internal iliac, being in length about two inches ; but its calibre was so small, having only admitted two or three drops of the coloured size, that it probably never carried red blood during life. No corresponding vessel was to be found on the right side, nor co\ild any further anastomoses be discovered between the arteries of the abdominal aorta and those of the pelvis or lower extremities. The branches of the thoracic aorta were not injected, and therefore not examined.* Dr. Monteiro's case. The subject of this operation laboured under a large false aneurism forming a tumor on the lower and right side of the abdomen and upper part of the thigh. The incisions were made pretty similar to those in Dr. Murray's case. The operation was performed at Rio Janeiro in 1842. The aorta was secured within the ligature after a good deal of difficulty in the operation: the patient died at the expiration of the tenth day after, from hemorrhage, which took place from a small opening in the vessel close to the ligature. On * Lond. Med. Gaz. 1834. MR. SOTJTH'S CASE. 216 examination after death it was found that the ligature had been applied about four lines above the bifurcation of the aorta, and that the precise nature of the original disease was an aneurism of the femoral artery in which the coats of the vessel had given way. Mr. South's case. No authentic report of Mr. South's operation of ligature of the abdominal aorta has been as yet published by himself; he has however most kindly favoured me with the following interesting particulars connected with his case : —" The man was thirty years of age and a hard drinker, —had had a strange uneasy sensation two months before his admission, and six weeks after noticed a small hard pulsating swelling in his right groin, which grew rapidly, and when admitted was as big as a goose egg.—Soon suffered paroxysms of violent pain, and leg became numb. Eleven days after, the aorta was tied without difficulty by a cut from the tip of the tenth rib to the superior iliac spine. In course of a few hours, first one, and subsequently the other limb became discoloured; was in constant profuse perspiration and exceedingly restless. Died forty-two hours after. Examination showed false aneurism of right external iliac artery." The foregoing cases suggest the following considerations : —in certain wounds the ligature of the aorta may be attempted :—in aneurism it can only be had recourse to in order to prolong life for a few days, as no surgeon would venture to propose so serious an operation for an early aneurism ; and, in an old one, it will in all probability fail, or may hasten the death of the patient. Under these circumstances would it not be more advisable to have recourse to internal or medical treatment than to propose an operation of so serious a character, and which we have no reason for hoping may be attended with success ? In considering the dangers and difficulty of the operation it may be well to observe that Dr. Murray's case shows that the aorta may be generally tied, without wounding the peritoneum ; and Mr. South's case that it may be tied "without difficulty." BRANCHES OP ABDOMINAL AORTA. CCSLIAC AXIS. 217 The branches of the abdominal aorta are the following, and from above downwards they arise in the following order :— Proper Phrenic, or Sub-Phrenic. Coeliac Axis. Superior Mesenteric. Capsular. Renal. Spermatic. Inferior Mesenteric. Lumbar. Middle Sacral. These arteries should, however, be dissected in the succeeding order : — The Coeliac Axis may be exposed by either of the following methods: the liver may be drawn upwards and the stomach downwards; by this means the gastro-hepatic or lesser omentum which connects them, will be brought into view : the anterior layer of this portion of the peritoneum being divided with caution near the pyloric end of the stomach, the hepatic vessels will be exposed, and the hepatic artery, by this dissection, may be easily traced to its origin. The coeliac axis may be also exposed by turning up the stomach together with the liver, and by tearing through the transverse mesocolon so as to arrive at the back part of the gastro-hepatic omentum. This artery arises opposite the body of the twelfth dorsal vertebra, and takes a direction downwards, forwards, and more frequently to the left than to the right side. After a course of about half an inch, it terminates by dividing into the gastric, hepatic, and splenic arteries. The coeliac axis has the superior margin of the pancreas beneath it, and this gland is frequently notched by the artery in this situation ; on its sides are the crura of the diaphragm, and the semilunar ganglia, which unite both above and below the artery, so as to form a nervous collar around its origin, from which streams forth a tube of nervous filaments, forming the solar plexus, which surrounds the artery. In front of this artery we find the lesser omentum ; the Spigelian lobe of the liver lies above and to its right side. 218 HEPATIC ARTERY. The branches given off by the coeliac axis are the following :— Gastric, or Coronaria Ventriculi. Hepatic. Splenic. The Gastric artery, or Coronaria Ventriculi, is smaller than the hepatic or splenic ; it proceeds at first upwards, forwards, and to the left side, to reach the cardiac orifice of the stomach : in this situation it often sends a large branch to the left lobe of the liver; but its constant branches are—first, an oesophageal branch or branches, which ascend, one in front of, the other, the more remarkable, behind the oesophagus : they supply this tube and anastomose with the oesophageal branches of the thoracic aorta; secondly, some coronary branches, which surround the cardiac orifice ; and, thirdly, a long descending branch, which follows the lesser curvature of the stomach, lying in a kind of triangular canal situated between the layers of the lesser omentum and the stomach : the artery is in this situation accompanied by some lymphatic vessels and glands, and by several branches of the left pneumogastric nerve : it sends numerous divisions over both surfaces of the stomach, and thus communicates with the arteries running along its convex margin. Having arrived near the pylorus, it terminates in anastomosing with the superior pyloric, which is a branch of the hepatic artery. We shall find that not the gastric artery only, but the three divisions of the coeliac axis supply the stomach, so that its margin is in fact circumscribed by vessels. The gastric branches of these vessels are situated between the layers of the peritoneum, and are not in contact with the margins of the stomach, unless in its distended state : this observation does not apply to the minute divisions which ramify on both surfaces of this viscus. The Hepatic artery is smaller than the splenic in the adult, but larger in the foetus: it proceeds at first almost Fig- 28.— Represents the Arteries of the Stomach and Liver. A, Abdominal Aorta. B, Coeliac Axis. D, Hepatic Artery. E, The Splenic: Artery a, a Proper Phrenic or Sub-phrenic Arteries, b, Anterior (Esophageal branch trom Coronary Artery. c,c, Gastric or Coronary Artery, d, Hepatic Artery, e, Superior rVlorip Artery anastomosing with the descending branch of Gastric Artery. < "e Vena Portte. g, Left Hepatic Artery. - i, Kight Hepatic Artery, k, Cystic Artery, m, Ductus Choledochus Communis, n,Hepatic Duct. I, Union of Cystic and Hepatic: Ducts, to form the Ductus Communis, o, The Gastro-duodenalis Artery, p, Gastro-epiploica Dextra Artery, q, q, Anastomosis between the Right and Left Epiploic Arteries, r, r, r. Omental branches from Epiploic Arteiy. 1, Under-surface of right Lobe of Liver. 2, Gall-bladder. 3, Undersurrace of left LobeTf Li'ver. 4, Lobulus Spifelii. 6, 5, Pillars of the faphragin 6 (Esophagus. 7, 8, 9, Stomach. 10, Pylorus. 11, Duodenum. 12,12,12,12, The Great Omentum. 13,13,13, The Small Intestines. 14,14, Peritoneum. 220 CIRCULATION IN THE LIVER. transversely along the superior margin of the pancreas, and beneath the Spigelian lobe of the liver, towards the upper and posterior surface of the pyloric extremity of the stomach: in this situation it gives off two branches, viz., the pylorica superior and gastro-duodenalis, and then proceeds upwards, forwards, and to the right side, surrounded by a considerable quantity of areolar tissue and branches of the solar plexus of nerves, all of which are situated between the two layers of the lesser omentum : in this part of its course it has the vena portae behind it, and the ductus choledochus to its right side. Having arrived in this manner within about an inch of the liver, it terminates by dividing into the right and left hepatic arteries, having, as already stated, previously given off the superior pyloric and gastro-duodenalis. The Superior Pyloric artery is small, and descends from right to left along the lesser curvature of the stomach : it supplies this organ, and anastomoses directly with the descending branch of the gastric artery, and by small branches which run across the stomach both anteriorly and posteriorly, with the arteries running along the great curvature of the stomach. The superior pyloric sometimes arises from the right hepatic. The Gastro-duodenalis artery, about two inches in length, descends behind the first portion of the duodenum, which it separates from the head of the pancreas, and divides into the gastro-epiploica dextra, and the pancreatico-duodenalis : the gastro-epiploica dextra, considerably larger than the latter, proceeds from right to left along the greater curvature of the stomach, both surfaces of which it supplies, and terminates in anastomosing with the gastro-epiploica sinistra, which is a branch of the splenic: its stomachic branches anastomose with the superior pyloric and gastric artery, and with the vasa brevia, while other long straight branches descend from its convexity, between the layers of the great omentum, to supply the transverse colon. The pancreatico-duodenalis, very small, SOURCE OF SECRETION OF BILE. 221 descends between the head of the pancreas and second portion of the duodenum: it supplies both of these parts, and sends a delicate branch between the inferior margin of the pancreas, and the third portion of the duodenum, to anastomose with the superior mesenteric artery. The right terminating branch of the hepatic artery ascends between the hepatic and cystic ducts anteriorly, and the vena portse and its right branch posteriorly, and sinks into the right extremity of the transverse fissure, to supply the liver : immediately after having passed behind the hepatic duct it gives off the cystic artery, which ascends between the hepatic and cystic ducts, and divides into two branches, one of which is distributed on the superior and the other on the inferior surface of the gall bladder. The left terminating branch of the hepatic artery, smaller than the right, ascends in front of the left branch of the vena portse, ultimately gets behind it, and sinks into the left extremity of the transverse fissure to supply the liver. CIRCULATION OF THE BLOOD IN THE LIVER. The Vena Porta is formed by the junction of the splenic vein, after it has received the inferior mesenteric, with the superior mesenteric vein. The trunk of this large vein commences on the front of the aorta, behind the superior margin of the pancreas, and opposite to the first lumbar vertebra : it then takes a direction upwards, and to the right side, to reach the transverse fissure of the liver, in which it divides into a right and left branch. In this course it is at first behind and between the hepatic artery and ductus choledochus, and higher up it is directly behind them. In the adult, the right branch, shorter and larger than the left, and more in the direction of the trunk itself, soon sinks into the right extremity of the transverse fissure, to supply the right lobe ; the left proceeds in the opposite direction, takes a longer course, 222 CIRCULATION OF THE FOETAL LIVER. forming nearly a right angle with the trunk, and sinks into the left lobe. We shall now endeavour to explain the distribution of these vessels in the foetus, and the manner in which the subsequent changes in their arrangement are effected. The Umbilical Vein in the Fmtus runs obliquely upwards, backwards, and to the right side, in the posterior or free margin of the falciform ligament of the liver : having arrived in the umbilical or horizontal fissure of this gland, it sends several branches to its left lobe, and one or two small ones to the lobulus quadratus ; then continuing it3 course backwards, it receives the left branch of the vena portse ; after having communicated with this branch, it passes between the Spigelian and left lobes of the liver ; and in this part of its course receives the name of the ductus venosus, which terminates finally in the inferior cava, or left hepatic vein. The Vena Portce in the Foetus divides into two branches; one of which sinks into the right lobe, the other runs towards the left lobe of the liver and terminates in communicating with the umbilical vein. On examining the distribution of these two large veins in the fcetal liver we will perceive that in reality the right lobe receives blood from the vena porta? only, but the left from both the portal and umbilical veins. This explains why the left lobe is so well developed at this period of life. After birth, however, the ductus venosus becomes entirely obliterated, but of the umbilical vein, its left branches, and a part of its trunk remain pervious, viz., that part of it in the immediate neighbourhood of the transverse fissure; for otherwise there would be no way for the blood of the porta to arrive at the left lobe of the liver. All the rest of the umbilical vein is obliterated. The use generally ascribed to the vena portse is to convey to the liver the materials for the secretion of the bile. Some, however, insist that the bile is secreted from arte- MR. kiernan's investigations. 223 rial blood; and others, as Mr. Phillips, that it may be indifferently secreted from either. In favour of the secretion from the portal blood, it has been said that the bile is of an oily character, and that the venous blood, being highly charged with carbon and hydrogen, is the best suited for its production. To this it has been replied, that fat, though compounded of carbon and hydrogen, is nevertheless separated by exhalation from the arterial blood. Again, the size of the vena portse is said by those who suppose the bile derived from it, to be suited to the size of the liver ; while the other party reply, that the vessel should be compared with the duct and not with the gland, they maintain that there is a proper proportion between the size of the hepatic artery and hepatic duct. There are at least four* cases on record, in which the vena portse did not go at all to the liver, but terminated in the inferior cava. It would appear, however, that in one of these cases the portal system of the liver was not absent, but the peculiarity was, that it commenced in a cul de sac. The same would probably be found in the other cases- if they had been accurately examined. M. Simon found, that if the hepatic artery be tied in pigeons, the secretion of the bile continues; if the portal vein and ducts be tied, it ceases ; and if the ducts alone be tied, the liver is gorged with bile. Mr. Phillips infers from his experiments, that the blood may be secreted from the blood of either artery or vein, as, whichever vessel was tied, the secretion continued. We shall now present the student with an abstract of Mr. Kiernan's valuable observations concerning the circulation and structure of the liver. Previous to his researches, it was supposed that the liver consisted of two different kinds of substance, termed the red tissue and * Lieutaud, Hist. Anat. Med. torn. i. p. 190. Huber, Observ. Anat. p. 34. Abernethy, Phil. Trans. 1793. Lawrence, Med. Chirurg. Trans, vol. v. p. 174. 224 MR. KIERNAN'S INVESTIGATIONS. yellov) tissue. Mr. Kiernan, however, by a series of well-conducted experiments, has shown that the red color depends on congestion of the blood vessels, and the yellow color on the absence of it. In order to make this more clear, let us attend to his exposition of the structure and arrangement of the vessels in the liver. According to Mr. Kiernan, each lobule of the liver has a conical form, and when divided longitudinally presents a foliated appearance ; and through its axis passes a small vein, termed the intra-lobular vein. This vein terminates at a right angle in a larger vein, which is applied to the base of the lobule ; this is accordingly called a sub-lobular vein. The sub-lobular veins terminate in the vence cava hepaticce, and these again in the vena cava inferior. Now all that portion of the exterior of a lobule, which does not constitute its base, is termed its capsular surface, because it is in contact with, and separated from the surrounding lobules by a process of the capsule of Glisson, which serves as a capsule for the lobule. Mr. Kiernan considers that the capsule of Glisson "is to the liver what the pia-mater is to the brain ; it is a cellulo-vascular membrane, in which the vessels divide and sub-divide to an extreme degree of minuteness ; it lines the portal canals, forming sheaths for the larger vessels contained in them, and a web in which the smaller vessels ramify ; it enters the interlobular fissures, and with the vessels forms the capsules of the lobules ; and it finally enters the lobules, and with the blood vessels, expands itself over the secreting biliary ducts. Hence, arises a natural division of the capsule into three portions, a vaginal, an interlobular, and a lobular portion ; and as the vessels ramify in the capsule their branches admit of a similar division." Thus, according to Mr. Kiernan, the capsule of Glisson enters the transverse fissure of the liver, and forms an internal lining for those canals called the portal canals, which convey the larger divisions of the vena portse into the interior of the organ; this, which is called the vaginal portion of the MR. kiernan's investigations. 225 capsule of Glisson, invests the primary divisions of the vena portse, hepatic artery, and the larger portions of the hepatic ducts : the term vaginal branches has, therefore, been applied to these divisions of the vessels surrounded by the vaginal portion of the capsule. The minute divisions of these three sets of vessels, together with the lobular portion of the capsule of Glisson, constitute the principal part of the lobules, so that, according to Mr. Kiernan, each lobule is composed, "on the outer surface of a capsule formed by a process of Glisson's capsule, of a plexus of biliary ducts, of a venous plexus formed by branches of the portal vein, of a branch of an hepatic vein, and of minute arteries : nerves and absorbents, it is to be presumed, also enter into their formation but cannot be traced to them." By taking the duct, artery and vena portse separately, we shall find how they are disposed of in the liver. First; the ducts penetrate the capsular surfaces of the lobules, and form in the interior of each, an extensive lobular biliary plexus ; from this plexus the bile passes into the interlobular branches, and then into the vaginal biliary plexus which goes to form the hepatic ducts. Secondly ; when the branches of the hepatic artery pass into the portal canals, they give off vaginal branches, these form the vaginal plexus of arteries which gives off the interlobular branches ; these pass through the interlobular fissures and give off the lobular branches which also penetrate the capsular surface of the lobules : they supply the parenchyma of the lobules, and the coats of all the vessels ; and the surplus quantity of blood not required for the nutrition of these parts, is conveyed into the minute branches of the vena portse. Mr. Kiernan remarks concerning the function of the hepatic arteries, " I conclude that the secreting portion of the liver, like the excreting portion of the kidney, is supplied with arterial blood for nutrition only. As all the branches of the artery of which we can ascertain the termination, end in branches of the portal vein, it is probable that the 226 MR. kiernan's investigations. lobular arteries terminate in the lobular venous plexus formed by that vein, and not in the intra-lobular branches of the hepatic veins, which cannot be injected from the artery, the blood of these arteries, after having nourished the lobules, becoming venous, and thus contributing to the secretion of bile." Thirdly; after the vena porta, has reached the transverse fissure of the liver it divides into branches which enter into the portal canals: here they give off the vaginal branches which constitute the vaginal plexus ; these then give off the interlobular branches, which in their turn give off the lobular branches. Finally ; these last, after piercing the capsular surface of the lobules, form, in their interior, a portal plexus or the lobular venous plexus of the porta, which, having received, as above mentioned, part of the blood conveyed by the arteries, furnishes the material for the secretion of the bile. Hence it appears that the bile is not secreted from arterial blood, but from venous derived from two different sources, one from the returned blood of the hepatic arteries which flows into the portal veins, the other from the venous blood of the porta itself. Thus, the branches of the vena porta? act as veins to the hepatic artery, and as arteries to the hepatic veins, which receive the surplus quantity of blood not employed in secretion. Now the appearances of the yellow and red tissues can be readily explained. The red tissue is owing to venous congestion : when this occurs in the hepatic system of veins, the centre of each lobule will be dark from engorgement of the intralobular veins; and, vice versa, when the congestion occurs in the portal system, the centre of the lobule will be light (constituting the appearance of yellow tissue,) but the circumference red, by engorgement of the portal veins investing it ; so that in one case we shall have dark spots on a pale ground : and in the other, pale spots on a dark ground. Mr. Kiernan could produce these appearances at pleasure, in experiments on animals, both in the liver, TODD AND BOWMAN'S OPINIONS. 227 and also in kidneys of those animals that have a portal renal circulation. According to Todd and Bowman, in the human subject the lobules are not isolated by a distinct capsule, but are Fig. 29.— Represents the Arteries of the Stomach, Duodenum, Pancreas and Spleen. The Stomach is turned upwards. A, Abdominal Aorta. B, Coeliac Axis. C, Gastric Artery. D, H