934 
replace one or more of the terminating branches 
of the internal pudic, and when present, always 
continues on to form the dorsal artery of the 
penis; it occasionally gives off the artery of 
the bulb and the artery of the crus penis, or 
this latter branch alone, during its progress. 
When the irregularity now described occurs, 
the pudie artery of the same side suffers a 
corresponding diminution in size, and stops 
short in the perineum after furnishing a variable 
number of branches. The irregular trunk here 
alluded to springs in general from the internal 
iliac, or from one of the branches of that 
artery; but from whatever source derived, it 
runs along the side of the prostate gland to the 
neighbourhood of the pubis, where it mounts 
above the urethra and passes beneath the sym- 
physis, in company with the dorsal veins of the 
penis. This irregular vessel runs nearly in the 
line of the incision in lithotomy, whether per- 
formed according to the lateral or the bilateral 
methods, and pursuing such an unfortunate 
course it can rarely escape the knife during 
these operations. Examples of this irregularity 
have been recorded by Blandin, Velpeau, 
Shaw, and others. 
The preceding description of the deep com- 
partment of the perineum would be imperfect 
without some application of the anatomy of that 
Space to practical purposes, particularly as the 
third incision in the lateral operation of litho- 
tomy is performed within its limits. In this 
step of the operation the surgeon, in order 
to make way for the calculus, cuts through 
the remainder of the membranous portion of 
the urethra, together with the left lobe of the 
prostate gland, and in doing so he must also 
divide Wilson’s muscle and some fibres of the 
levator ani. From the many important parts 
which surround the prostate, this incision is 
beset with difficulties. The rectum is much 
endangered ; this arises from its proximity to 
the under surface of the prostate gland, and 
from its occasional dilatation. To insure the 
safety of the gut it should be emptied by the 
administration of an enema previous to the 
operation; the handle of the staff should also 
be depressed before the third incision com- 
mences, and the edge of the knife should be 
duly lateralised ; without the latter precaution 
all other expedients to save the intestine are 
useless. The depression of the handle of the 
staff raises the beak of the instrument behind 
the pubis, and causes the knife to enter the 
bladder as much as possible in the axis of that 
viscus, a line of incision best calculated to 
protect the bowel; and by performing this 
manceuvre at the proper moment the operator 
raises the prostatic portion of the urethra from 
the rectum, thus contributing still further to 
the sa of the gut. 
Hemorrhage is the most formidable conse- 
quence of the third incision in lithotomy. The 
pudic artery incurs a certain amount of risk 
when the operator, in his anxiety to save the 
rectum, directs the edge of the knife too much 
outwards, but from a former part of this article 
the reader may perceive that such an accident 
is of rare occurrence. The irregular artery 
PERINEUM. 
which runs along the prostate is much more to 
be dreaded, for the surgeon can neither foresee 
nor avoid the danger, and from its position all 
attempts to tie the vessel when wounded must ne- 
cessarily prove fruitless, whilst the absence of a 
resisting surface beneath the bleeding orifice pre- 
vents the plug from commanding the hemorrhage. 
A profuse loss of blood from the vesico- 
prostatic plexus of veins may be also encoun- 
tered, and is most likely to happen in elderly 
persons. The largest of these vessels are situ- 
ated at the neck and along the base of the 
bladder, so that the surgeon guards against 
such a casualty most effectually by confining 
his incisions as much as possible within the 
limits of the prostate gland. “° 
The French writers consider phlebitis and 
diffuse cellular inflammations to be the most 
common causes of death after lithotomy, and 
they attribute both these fatal affections to an 
incision carried beyond the base of the —— 
They maintain that the cut surface of the gland 
is sufficiently tough and resisting to bear the 
urine with impunity, and that the lax cellular 
membrane around the neck of the bladder, 
and the veins in the same locality, speedily — 
inflame when irritated by that secretion. 
Paris the bilateral operation is therefore mostly 
practised, as it gives the largest incision prac- — 
ticable within the circumference of the prostate 
gland, at the same time that it protects the — 
common ejaculatory ducts, the rectum, and the 
pudic artery from injury. 
In these countries the lateral method is still — 
generally preferred, whether it be that British — 
surgeons usually find a section of one side of 
the prostate sufficient for the extraction of the 
calculus, or that a moderate division of the 
neck of the bladder in their hands seldom 
leads to the above described unfortunate results 
particularly if a ready outlet for the urine be 
ensured by a free section of the superficial 
Structures. 
In the bilateral operation a double risk o 
wounding the irregular dorsal arteries of t 
penis must be incurred ; and should the bl 
of the lithotome, in consequence of a misee 
ception of the width of the prostate gland o 
of the transverse measurement of the be 
boundary of the perineum, be too widely di 
varicated, a twofold liability to venous he: 
rhage and to injury of the rectum will be dl 
result, and the pudic vessels on both sides 1 
be endangered,—accidents which demand ¢ 
consideration from the practitioner in weigh 
the relative merits of these rival operations. 
In dividing the prostate gland the knife 
apt to slip from the groove of the staff 
reason of the great toughness of the cap: 
and to pass between the rectum and bla 
causing extreme mischief. When this pat 
the operation is performed with the si 
knife, the lithotomist guards against st 
unpleasant accident by incising the mem 
nous portion of the urethra freely before 
commences the third incision, and by depre 
ing the handle of the knife considerab 
pushes its blade onwards to the bladder; 
the former precaution he makes certain that 
