934 



PERINEUM. 



replace one or more of the terminating branches 

 of the internal puclic, 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 pudic 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 

 manoeuvre at the proper moment the operator 

 raises the prostatic portion of the urethra from 

 the rectum, thus contributing still further to 

 the security 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 



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 plugfrom 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 prostate. 

 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. In 

 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 of 

 wounding the irregular dorsal arteries of the 

 penis must be incurred ; and should the blades 

 of the lithotome, in consequence of a miscon- 

 ception of the width of the prostate gland or 

 of the transverse measurement of the bony 

 boundary of the perineum, be too widely di- 

 varicated, a twofold liability to venous hemor- 

 rhage and to injury of the rectum will be the 

 result, and the pudic vessels on both sides will 

 be endangered, accidents which demand due 

 consideration from the practitioner in weighing 

 the relative merits of these rival operations. 



In dividing the prostate gland the knife is 

 apt to slip from the groove of the staff by 

 reason of the great toughness of the capsule, 

 and to pass between the rectum and bladder, 

 causing extreme mischief. When this part of 

 the operation is performed with the simple 

 knife, the lithotomist guards against such an 

 unpleasant accident by incising the membra- 

 nous portion of the urethra freely before he 

 commences the third incision, and by depress- 

 ing the handle of the knife considerably as he 

 pushes its blade onwards to the bladder; by 

 the former precaution he makes certain that the 



