PA It A I. V SI S OF THE MUSCLES OF THE 
ABDOMINAL WALL DUE TO INJURY 
TO NERVE TRUNKS DURING OPER- 
ATION.* 
BY WM. O.MCDONALD. 
NKW YORK. 
This condition has been spoken ot as 
a form of ventral hernia. Inasmuch as it 
concerns the belly it is ventral, but I do 
not see that the term hernia is the most 
appropriate. Gould’s Medical Dictionary 
defines hernia as being “a tumor formed 
by the protrusion of the contents of a 
cavity through its wall.” It cannot be 
said, I think, that the contents of the ab- 
domen are protruded through the wajl as 
a sequence of this lesion. Qfpf 
The case I wish to that of a 
woman, perhaps thirty-five years old, 
rather less than five feet high, who weighs 
about one hundred and seventy pounds, 
with, as I found, on operating, between 
two and three inches of fat upon the ab- 
dominal wall between the skin and the 
fascia covering the flat muscles. On ac- 
count of a neglected appendicitis I was 
obliged to make an incision oblique in 
direction, running parallel with, and 
starting opposite to the middle of, Pou- 
part’s ligament, extending upward and 
outward into the lumbar region of the 
abdomen. Just how extensive this cut 
was I am not able to indicate; the scar in 
the skin is now eight and one-quarter 
inches long. After a rather trying time 
the wound healed and the natient wrnt 
•New York County Homoeopathic Medical 
Society. to Europe. She returned in the fall, and, 
coming to me, stated that two supporters 
which she had had made did not serve the 
purpose in a satisfactory manner. Upon 
making an investigation I found that 
owing to obesity it was difficult to be 
exact, but as far as I could ascertain there 
has been no particular yielding of the 
scar. There appears to be no ventral 
hernia at the site of the incision. But 
changes of a very different sort have 
taken place — the whole right side of the 
muscular abdominal wall seems to have 
yielded in all its diameters, vertical, ob- 
lique and transverse. The right side of 
the abdomen appears to contain pretty 
much all of the intestinal contents. The 
condition will be best understood by re- 
calling the changes which are witnessed 
in Bell’s paralysis of the face, where the 
tissues of the paralyzed side are dragged 
to the sound side, the mouth, chin and 
median line tissues showing off the de- 
formity after a notable fashion. 
Of course the explanation is not far to 
seek. In making the extensive incision 
enough of the nerve trunks which supply 
the right side of the abdominal muscular 
apparatus were divided, and, as the wound 
healed by granulation and from the bot- 
tom, these severed trunks have had no 
chance later to pick up ends, and thus to 
re-unite, as it is stated they sometimes 
do. The abdominal wall muscles of the 
right side, paralyzed by the loss of nerve- 
supply, yielded to the pull of the sound 
muscles in the left side, and to the bulg- 
ing tension exercised by the soft abdom- 
inal contents, and for a termination we 
have the greater part of the mobile ab- 
dominal contents contained in the swell- 
ing: right side of the belly. Owing to circumstances, needless for me to specify, 
1 was not able to make a new extended 
examination of this case, such as the use 
of electrical tests, to determine what mus- 
cles and what amount of muscle was af- 
fected. Nor could I investigate the 
amount and degree of dermic sensory dis- 
turbance. Nor was I able to note the 
effect of induced muscular action of the 
sound muscular structure in exaggera- 
ting the deformity. 
There was nothing noted by palpation 
or percussion to suggest that anything 
other than intestinal structures — mes- 
entery and omentum were contained in 
the bulging right side of the belly. There 
were no evidences of fluid, and there cer- 
tainly was no circumscribed mass, such 
as a tumor would form. 
The reason why the supporters which 
the woman had used had failed was easily 
to be perceived; they were not wide 
enough vertically when applied to fur- 
nish the lifting support needed in the 
lower part of the belly, and to supply at 
the same time the girdle-like pressure 
which wras demanded above the um- 
bilicus. 
In submitting the case to Ford & Co. 
to be fitted I was able to make a sugges- 
tion which appeared to work very well 
when put into practice. It was this: The 
bandage when applied to the median an- 
terior abdominal wall had to be quite 
wide (I have not the dimensions) in or- 
der to meet the difficulty developed by 
the defects found to exist in the old sup- 
porter. The supporter was made wide 
enough to permit of continuous applica- 
tion from the extreme lower part of the 
hypogastric region below, to the median 
portion of the epigastric region above. 
3 4 
Of course it needed a great deal of shap- 
ing and fitting to ensure neat and accur- 
ate application over this extensive area. 
And when this was done it was impossi- 
ble to continue the supporter around 
where it was to be applied to the lumbar 
region of the back, in the same width, 
and to get at the same time the compres- 
sive force applied in two directions by the 
one apparatus. In order to remedy this 
difficulty and to fit the two kinds of pres- 
sure, the expedient of splitting the band- 
age in its long diameter at its ends was 
resorted to. The supporter was divided 
at each end in its long axis for about 
one-third its length, thus leaving the 
middle third undivided, when it was to 
be applied to the anterior and bulging 
portion of the abdominal wall. By ap- 
plying and lacing of the inferior portion 
first, the support of a lifting charac- 
ter was applied to the lower part of the 
abdominal wall. By applying the su- 
perior portion exactly over the inferior 
around the lumbar region of the back, 
the girdle-like action was brought into 
play; and when made and thus applied 
this supporting bandage was found to 
work very well. 
Support applied after some such fash- 
ion is the only remedy which I propose 
to apply in this case, but it has occurred 
to me that it is possible that in a more 
recent case it might be found advisable 
to attempt to obtain a restoration of 
function to the damaged motor nerves by 
dissecting out the nerve ends and making 
the attempt to suture them. 
In the discussion which followed the 
reading of this paper it was said bv one 
speaker that these nerve trunks were 
too small to permit of sutures being sue- 5 
cessfully carried out. But I have read 
somewhere the statement that nerve- 
trunk tissue is the only one in the human 
body which has to any appreciable ex- 
tent the capacity of reproduction — 
actual reproduction after destruction — 
reproduction shown to exist not only by 
restoration of function, but also by anat- 
omical demonstration. The account sta- 
ted, in addition, if I quote it properly, 
that a reproduction of a nerve-trunk to 
fill a gap had been noted one inch long. 
The clinical evidence that some such res- 
toration of function may come to pass is 
sufficiently abundant and convincing, in 
view of the frequency with which the op- 
eration of neurectomy has been known to 
fail when applied as a remedy for neu- 
ralgia. Besides it still remains to be 
ascertained that the joining of nerve- 
trunks for the purpose of obtaining res- 
toration of function necessitates the 
actual maintenance in contact of the di- 
vided ends, which we deem to be essential 
in other sutured tissues. In view of the 
power of reproduction claimed for nerve- 
trunk fibre, may we not expect something 
of the kind to take place if we put the 
separated ends in the immediate vicinage 
of each other, where they seem to be too 
small for actual needle-and-thread work? 
Of course, it is to be understood that 
this is done before hopeless degenera- 
tion has set in. And it is also to be men- 
tioned that what I have said is conjec- 
tural, but the assumption that any nerve- 
trunk is too small for union to be brought 
about is also conjectural. 
The diagnosis of this lesion is worthy 
of some consideration. As is the case 
with Bell’s paralysis of the face, mistake 
will usually be due either to want of 6 
knowledge or to superficial examination. 
Bell’s paralysis can be easily confounded 
with disease implicating the second 
branch of the fifth pair, and I have known 
this mistake to be made. I will now ven- 
ture .that quite a proportion of the med- 
ical men in active practice who read this 
article will be unable to make the distinc- 
tion between these two paralyses off- 
hand. There are several varieties of path- 
ological lesions which can be profitably 
considered in this relation. The condi- 
tions which occur to me as needing con- 
sideration are: 
I. Ventral Hernia. 
II. Atrophy of the muscles of the ab- 
dominal wall, general and symmetrical; 
III. Tumor, lateral, of the abdomen, 
fluid, solid or mixed. 
As I have already intimated, lateral 
paralysis of the muscles of the abdominal 
wall cannot be mistaken for any other 
condition with which I am familiar, pro- 
vided its characteristics are borne in 
mind. The motor nerve supply appears 
to be common to the two obliques trans- 
versalis, and to the rectus, and the changes 
are due to the relaxation of these former 
muscles, and are presumably in extent in 
direct proportion to the amount of dam- 
age inflicted upon the nerve-trunks. 
Before taking up the anatomy of this 
disorder I wish to say something about 
those pathological states which are allied 
to it. 
First, as to ventral hernia. I would 
submit that the term can conveniently be 
applied to all hernias to which a specific 
name has not already been given. This 
will exclude all forms of inguinal, femoral, 
umbilical, perineal, etc.; it will include 
all forms of protrusion at irregular sites, 7 
and pretty much all forms due to injuries 
and operations. A number of years ago 
Dr. B. F. Joslin, Jr., read an article be- 
fore this Society reporting a case of ven- 
tral hernia, actuated in this by the idea 
that he was making known an unusual 
and rare case. He based this supposition, 
he said in his article, upon what he found 
in some English work on surgery, where- 
in the author said that ventral hernia 
was so rare that a case of it was a surgical 
curiosity. If this were so at that time, 
it is not so now. And I think I am in po- 
sition to say that in all probability the 
statement made by the English author 
was inexact for pretty much any time. 
I know that among the soldiers of the 
United States army during the war of the 
rebellion I met with quite a number of 
cases of ventral hernia, and it seemed that 
as far as concerns the origin of these 
cases they could be divided into two 
classes with reference to cause. One 
class, located in the median line, was held 
to be congenital, as the subjects stated 
that they were there as long as they could 
remember. I held them to be due to de- 
fects of development. The other class 
were irregular in location, and were as- 
sociated usually with a history of injury, 
certainly at times not associated with 
scar of the dermic surface. Not infre- 
quently these were said to have followed 
bruises of the wall. Conjecturally, I as- 
sumed in these cases that subcutaneous 
wounds and lacerations had taken place. 
During my service as examining surgeon 
of pensions, from 1877 to 1885, I saw a 
good many more ventral hernias, and 
then I also noted that they were attribu- 
ted by their owners, almost without ex- 
ception, to injuries, gun shot or other, re- 8 
ceived while serving in the army or navy. 
Since I ceased, in 1885, to be an examin- 
ing surgeon pretty much all of the cases 
of ventral hernia which have come before 
me have been the result of operations 
upon the abdominal wall. And here again 
I could divide them into two classes: 
I. Those due to the insertion of a scar 
into the muscular wall of the cavity; 
II. Those due to the yielding of cut 
surfaces, which having been united, 
usually by suture, have later separated 
over perhaps quite a wide area, generally 
linear in kind at first, producing at times 
quite an extensive gap in the parietes of 
the cavity. These hernias are still being 
produced in goodly numbers. 
A mass of cicatricial tissue anywhere 
in the wall of the abdomen certainly is 
a weak spot. This is demonstrated by ex- 
perience. And at this weak spot pro- 
trusion is apt to take place, particularly 
if the cicatrix penetrates all the layers, 
fascial as well as muscular. 
Ventral hernia can always be distin- 
guished from the lateral deformity pro- 
duced by the motor paralysis described 
by the facts that the bulging or protru- 
sion will take place at the site of the scar 
in hernia, whereas in paralysis it will be 
remote in its location. 
Another condition which may be con- 
trasted with lateral paralysis I have met 
with twice. The only way in which I can 
characterize it is to call it general sym- 
metrical wasting of the muscular portion 
of the abdominal parietes. These two 
cases were each of them women who had 
borne a number of children. In each 
case the walls had lost entirely the sub- 
stance and rigidity, tonicity, may I say, 
which is ordinarily found. Not only the Q 
muscular substance, but also all adipose 
tissue seemed to have been removed, 
seemingly nothing but skin and soft 
fascial tissues covered the contents. The 
intestines, considerably distended, could 
be readily stimulated to rather rapid ac- 
tion by rubbing and manipulation with 
the fingers, until they would writhe and 
twist about in a fashion that was un- 
canny and almost shocking to behold, be- 
ing so strongly suggestive of the pres- 
ence of a serpent in the cavity. Nothing 
analogous has ever been witnessed by me 
in any case where by action I have ex- 
posed the intestinal tube. 
Of these cases, I recall one very dis- 
tinctly; the other more dimly; but when 
I saw the second case I was able to say 
that I had met with the condition before. 
Both of these women wore bandages 
of muslin of their own devising and ap- 
plication, and neither of them came to me 
on account of state of the abdominal wall. 
In neither was there any great degree 
of hanging of the abdomen, a condition 
which has always been associated in my 
mind with a material amount of fat ac- 
cumulation in the mesentery, omentum, 
or under the skin. I was not able to ac- 
count for this general and symmetrical 
wasting of the abdominal wall, and I am 
now equally unable to explain it. Should 
similar cases have come to the notice of 
anv of the readers of the Medical Era I 
would be glad to be informed, particular- 
ly so if any adequate explanation can be 
offered. 
When it comes to the distinction of 
lateral paralysis from tumor of one side 
of the abdomen, the detection and cir- 
cumscribing of the mass of the tumor will 
be the first step. This done, it will be 10 
easy to determine that the umbilicus and 
median line tissues, if they go at all, will 
go to the side of the tumor location, and 
not to the opposite side, as is plainly the 
case in lateral paralysis. 
The essential lesion being the fact that 
motor nerves are put out of function, the 
amount and extent of yielding of the 
muscles will depend upon the number of 
motor nerves damaged, and here the 
anatomy of these nerves becomes im- 
portant. 
It has been one of the common re- 
proaches cast at our profession that it 
does not approximate to such position, 
as would justify the term of an exact 
science being applied to it. Without 
really considering the question seriously, 
I have in my own mind rather resented 
this, and particularly with reference to 
anatomy. Several times, however, within 
the past few years I have had occasion to> 
refer to standard works upon anatomy for 
information, specific and exact, about 
particular structures. The results of such 
references have been at times disappoint- 
ing. 
And in the matter of the relations of 
the motor nerves to the large abdominal 
muscles the manuals do not give exact 
information, as will be seen from what 
follows. 
Gray says the lower intercostal nerves 
supply twigs to 'the abdominal muscles, 
mentioning the two obliques the trans- 
versalis, and the rectus; in another place 
he says that the abdominal muscles are 
supplied by the lower intercostals, and by 
the ilio-hypogastric and the ilio-inguinal. 
Harrison Allen, “Human Anatomy of 
the Nervous System,” says nothing about 
those nerves being distributed to the ab- 11 
dominal muscles, nor does he give the 
destination of the lumbar branches. 
Tilleaux, “Topographical Anatomy,” 
states that the nerves of the antero-ab- 
dominal walls are derived from the five 
lower intercortals, and the two abdomino- 
genital ; these are the ilio-hypogastric and 
the ilio-inguinal. He also says they “ani- 
mate” the rectus. 
the latest French authority, p. 
714, Vol. II., goes into the description of 
the nerves supplying the abdominal wall 
in more detail, and he gives a plate of their 
ramifications. He says that the sixth and 
seventh intercostals furnish branches to 
the external oblique and to the rectus. 
Of the eighth, ninth, tenth and eleventh 
intercostals he says they give branches 
to the large abdominal muscles; also that 
branches from them go to the rectus. He 
figures the twelfth intercostal as doing 
much the same thing, and as going into 
the substance of the rectus and supplying 
the portion of the lower belly, which is 
midway between the umbilicus and the 
pubes. His plate represents the ilio-hy- 
pogastric as supplying the part of the in- 
ferior belly of the rectus from this area 
to the pubes. In addition, he states that 
the ilio-hypogastric gives branches to 
the flat muscles. Of the ilio-inguinal he 
says it partakes of the distribution of the 
preceding and also that it finally sends 
branches to the abdominal muscles, and 
also that the genito-crural sends twigs to 
the transversalis. 
Sappey, another French author, coin- 
cides in the main with Jestut. 
Quain, Schafer and Thane, Vol. III., 
part II., p. 309, figures the sixth inter- 
costal as sending branches to the anterior 
abdominal wall behind the upper part of 12 
the rectus. It is to be borne in mind that 
the rectus arises from the cartilages of 
the fifth and sixth ribs, 'but this area will 
probably never be attacked by the sur- 
geon, and these branches are so small as 
to be unimportant. The seventh is por- 
trayed as going to the wall in the upper 
part of the epigastric region, the general 
drift of the direction of branches being 
ascending. The eighth nerve acts the 
same at a lower level, the general ten- 
dency being to ascend. The ninth occu- 
pies the next space, which reaches nearly 
to the umbilicus, the branches being hori- 
zontal in their gross direction. The tenth 
in its area envelops the umbilicus. The 
eleventh and twelfth descend much more 
rapidly as they reach to the lower parts 
of the abdominal wall. 
Quain’s plate corresponds most close- 
ly with the results obtained by Dr. Se- 
ward in his dissection, but Quain’s de- 
scriptions are brief and unsatisfactory. 
The following account of nerve-distri- 
bution has been prepared for me by Dr. 
J. Perry Seward, from recent dissections: 
“The nerves that may be severed in 
lateral abdominal and lumbar incisions 
are the lower six intercostal nerves and 
the two divisions of the first lumbar nerve, 
the ilio-hypogastric and ilio-inguinal. A 
brief practical description of their course 
and distribution may aid in determining 
the direction of incisions calculated to 
avoid them. 
To begin below, we can promptly 
rule out of the discussion the lumbar 
nerves. The ilio-inguinal is only in 
danger near its origin, as it crosses the 
anterior surface of the quadratus lum- 
borum muscle. It then passes between 
the transversalis and internal oblique 13 
muscles, so close to the iliac crest as to 
be amply protected. In the abdominal 
wall it is so near Poupart’s ligament as 
to be safe in abdominal operations. The 
muscular distribution is very slight, lim- 
iter! to a few fibres of the internal oblique 
near the iliac crest. 
“The ilio-hypogastric from the middle 
of the outer border of the quadratus 
lumborum traverses the abdominal wall 
between the transversalis and internal 
oblique, running obliquely downward 
and inward. In the greater part of its 
course it is divided into two parallel 
trunks, a half inch apart. Its distribution 
is a matter of dispute at the present time, 
the point at issue being whether it sup- 
plies any of the lower part of the rectus 
abdominis. In five dissections under- 
taken to determine this point, the writer 
traced the nerves to the outer border of 
the sheath of the rectus, between the 
middle and lower thirds of the section ex- 
tending from the umbilicus to the os 
pubis. In two subjects it could there be 
plainly seen to enter the superficial fascia 
over the hypogastrium. In three cases 
the nerve was lost in the aponeurosis, and 
its final distribution undetermined. But 
in no dissection could any trace of it be 
found within the sheath of the rectus. 
Gray’s description, therefore, which 
limits its distribution to the skin over the 
hypogastrium, is probably correct, al- 
though no rule of nerve distribution can 
be considered absolute. 
“It is therefore the course of the lower 
six intercostal nerves that must be con- 
sidered with a view to the prevention by 
their preservation of paralysis. In the 
thoracic wall they occupy a position close 
to the lower border of their respective 14 
ribs, between the internal and external 
intercostal muscles. They continue their 
course toward the median line of the ab- 
domen, resting upon the anterior sur- 
face of the transversalis muscle. This 
latter muscle takes part of its origin from 
the posterior surfaces of the six lower 
costal cartilages. The nerves, therefore, 
pass between the cartilages and the trans- 
versalis to reach the abdominal wall. 
Their direction varies, for they radiate 
from the edge of the subcostal angle. 
“The seventh intercostal nerve, after 
passing behind its cartilage, runs upward 
and inward close to the cartilages, to a 
distribution in the rectus. It is so near 
the thoracic wall as to be in little danger 
of section. The eighth nerve diverges 
decidedly from the side of fhe subcostal 
angle, while the ninth has an almost hori- 
zontal course, only slightly upward. The 
tenth, eleventh and twelfth intercostal 
nerves increase the obliquity of their 
course from above downward. They are 
usually found dividing soon after they 
leave the ribs into two trunks, which take 
a parallel course about a half inch apart. 
Each pair of nerves is separated by about 
an inch and a half. 
“Upon reaching the sheath of the rec- 
tus the nerves penetrate the aponeurosiSi 
and continue their general direction be- 
hind the muscles, the lower nerves, par- 
ticularly the twelfth, bending slightly 
more downward. At a point an inch or 
less from its outer edge they enter the 
muscle and are distributed in its sub- 
stance. 
“The operator may therefore expect to 
find a series of nerves lying between the 
internal oblique and transversalis mus- 
cles radiating from the extremities of the 15 
ribs to the linea semilunaris. They vary 
from a half inch to an inch and a half 
apart. Their distribution being both mus- 
cular and cutaneous, it is in the highest 
degree desirable to preserve them from 
injury, particularly since they are too 
tenuous to permit suture after section. 
“The last intercostal nerve extends 
downward and inward from just below 
the anterior extremity of the last rib to 
the linea semilunaris opposite the mid- 
dle third of the lower belly of the rectus. 
Below and behind this nerve all trunks 
exposed are cutaneous in distribution, 
except the ilio-inguinal, which hugs 
closely the iliac crest and Poupart’s liga- 
ment.” 
It will be seen by Dr. Perry Seward’s 
report that he ignores the sixth inter- 
costal nerve as being out of the field; that 
the trunk of the seventh coursing upward 
and inward in so far under the shelter 
of the costal cartilaginous border as to be 
practically safe from injury; that the 
trunk of the eighth is really the only one 
that can be said to pass upward and in- 
ward in the anterior abdominal wall where 
it would be liable to be severed during 
operation: that the ninth is practically 
horizontal in its direction; while the rest 
of the dorsal nerves have a direction 
downward and inward, becoming less 
transverse as they descend to the twelfth, 
which enters the sheath of the rectus op- 
posite the middle of the inferior belly of 
the muscle, which extends from the um- 
bilicus to the pubes. 
Consequently, I feel warranted in say- 
ing that above a line drawn horizontally 
forward from the tenth rib horizontal 
incisions will not sever more than one 
nerve trunk: and also that below this 16 
line oblique incisions should not sever 
more than one trunk if suitably inclined 
after an increasing fashion in descending. 
In the August number of the “Annals 
of Surgery” Kammerer, in speaking of 
the way in which he has operated for 
appendicitis, says that in two cases in 
which he made a vertical incision through 
the wall of the abdomen, located some- 
what to the inner side of the linea semi- 
lunaris, in order that he might go 
through the rectus muscle, or pull it to 
the inner side and leave it intact, that he 
cut the branch of the ilio-hypogastric 
nerve which supplies that part of the 
rectus muscle and that in each case this 
was followed by atrophy of the corre- 
sponding portion of the rectus. 
In the “Medical Record,” Feb. 26, ’98, 
p. 321, H. L. Hibbard, M. D., in a com- 
munication criticises Kammerer’s con- 
clusions, first, by saying that the nerve 
supply of the rectus is through the lower 
intercostals, and not from the ilio-hypo- 
gastric. He also rather implies that one 
of the liniae was taken for an 
atrophic spot in the muscle, and in ad- 
dition he states that the ilio-hypogastric 
goes to the skin almost wholly, and to 
muscle not at all, or at least to a very 
slight extent. 
By recent writers Kocher, a German, 
is credited with being the first to call at- 
tention to the probability of injury being 
inflicted upon nerve trunks in making 
sections of the abdominal walls, and 
writing with particular reference to gall- 
bladder operations, he advises that the 
incisions should be made in an oblique 
direction, but I find nothing to indicate 
the particular oblique in which he would 17 
cut, whether it was to be inward and up- 
ward, or inward and downward. 
In the January number of the “Annals 
of Surgery,” 1898, Geo. Woolsey, Sur- 
geon to Bellevue Hospital, has an article 
on abdominal incisions, from which I ex- 
tract the following: “A most important 
and too often neglected element of the 
abdominal walls are its nerves, compris- 
ing the six lower dorsal, the ilio- 
hypogastric, and the ilio-inguinal nerves. 
Their motor portions pass for the 
most part between the internal ob- 
lique and transversalis muscles, which, 
together with the external oblique, they 
supply, and they pierce the rectus mus- 
cle to furnish its motor nerve supply. 
The direction of these nerves is of great 
importance, as pointed out by Kocher, in 
determining the direction of abdominal 
incisions, for their division causes paresis 
and atrophy of the muscles, w-eakens the 
abdominal wall, and predisposes to 
hernia. In the anterior abdominal wall 
their nerves pass downward and inward 
in the lower third (i. e., the eleventh and 
twelfth intercostal and the ilio-hypogas- 
tric and the ilio-inguinal) nearly trans- 
versely inward in the middle third (i. e., 
the ninth and arffllh. intercostals) and 
upward and inward above (i. e., the sev- 
enth and eighth intercostal nerves.)’’ Re- 
cently I have had an opportunity to in- 
spect the scar upon the abdomen of a 
young woman nephrectomy, and/ 
later a ureterectomy was done on the 
right side. In her case there was no evi- 
dences of any damage having been in- 
dicted upon the motor nerve trunks, al- 
though the scars, two in number, have a 
united extent at least as great as in the 
case reported by me. Starting from just 18 
below the twelfth rib in the right lumbar 
region of the back, extending forward 
and downward with one slight interrup- 
tion across the lumbar region of the ab- 
domen, past the anterior superior spine 
to a point opposite the middle of Pou- 
part’s ligament, an entire compass of 
eight and a half inches. There are some 
anaesthetic areas, but no signs whatever 
of motor paralysis. 
My case shows that an incision of over 
eight inches long, although oblique in 
direction, may inflict so much damage 
upon the motor nerve trunks of that side 
of the belly as to make it appear that 
pretty much all the abdominal muscles 
are paralyzed. While the other case 
shows that a scar equally extensive may 
be left by incisions which, although lo- 
cated in close proximity, apparently fail 
to produce any lesion whatever of the 
motor apparatus of the vicinity. 
The two cases suggest the necessity 
for careful study of the location of the 
motor nerve trunks in carrying out op- 
eration into the performance of which 
section of the abdominal wall enters. 
During the discussion which followed 
the reading of my article it was said that 
apparently the nerve trunks would have 
to suffer anyway, when incisions were 
made through the abdominal wall. I am 
not prepared to accept this conclusion as 
valid; not in all cases, at any rate. The 
two cases cited by me go to show every- 
thing may depend upon the direction of 
the incisions. The anatomists appear to 
agree in descriptions which will warrant 
me in saying that all vertical sections 
which go through the rectus will divide 
nerve branches in direct proportion in 
number to the extent of these incisions, 19 
presumably, however, the damage in- 
flicted by these vertical incisions upon 
nerve tissue will in its results be slight 
because of their proximity to the median 
line and to the terminal areas of nerve 
distribution. Consequently, as far as the 
nerve trunks are concerned, we can cut 
with a free hand in what I will call the 
territory of the rectus muscles, shaping 
our incisions without reference to nerve 
anatomy. 
Outside of the territory of the rectus, 
however, matters vary, my conclusions 
being that above the tenth rib horizontal 
line, horizontal incisions, will do but lit- 
tle damage, and below the tenth rib line, 
oblique incisions may be managed in 
such a way as not to damage nerve trunks 
at all, and yet to extend from near the 
spine in the lumbar region of the back 
to at least opposite the middle of Pou- 
part’s ligament in front. 
Still another point is worthy of com- 
ment. It may occur to some to ask how 
I account for the fact that in my case, in 
which I have described incision as run- 
ning parallel with Poupart’s ligament up- 
ward and outward, I did so much dam- 
age to the motor nerve trunks. In an- 
swer to this it may be said that a line 
drawn parallel with Poupart’s ligament 
removed from it from one-half inch to 
one-and-a-half inches will, if extended 
upward, strike the borders of the thorax 
at points varying with the amount of ob- 
liquity of the pelvis in the individual upon 
whom this measurement is made. And 
it also may be stated that in no case will 
this line be sufficiently oblique to save 
the nerve trunks of this area from the 
probability of damage, and I think that it 
follows that in case extended incisions 20 
are required, while the line opposite Pou- 
part’s ligament may be parallel with it 
after passing the anterior superior spine, 
the direction must be changed somewhat 
more backwards to terminate just below 
the border of the twelfth rib near the 
spine, if we would minimize as much as 
possible the risk of dividing nerve trunks. 
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