PRACTICAL CONSIDERATIONS : MALE PERINEUM. 



1921 



of the prostate, necessitating the division of more of the vesical neck and increasing 

 the risk of opening up the pelvic fascia ; (c) the greater mobility of the bladder 

 (the neck of which in the adult is largely fixed by its connection with the base of 

 the prostate), so that it has been pushed before the linger and torn from the urethra ; 

 {d) the situation of the bladder above rather than in the pelvis, the neck, therefore, 

 being relatively higher than in the adult ; {e) the looseness and delicacy of the 

 recto-vesical fascia, permitting the easy separation of the bladder and rectum and 

 forming a cavity which the hnger may mistake for that of the bladder ; {/) the 

 relatively low level of the recto-vesical fold of peritoneum, exposing it to injury if the 

 wound is unduly prolonged upward. 



Median lithotomy involves the division, through the median raphe of the peri- 

 neum, of the skin, superficial fascia, sphincter ani and portions of the other struc- 



FiG. 1631. 



Corpus spongiosum, cut 



Adductor brevis 

 Corpus cavernosum 



Adductor magnus 



Ramus ischii 



Biceps and 

 semitendinosus 

 Tuber ischii 



Obturator internus — 



Cut edge of anal — 

 fascia 

 Cut edge of levator — 

 ani 



■greater sacro-sciatic 

 ligament  



Gluteus maximus, 

 cut 



Corpus cavernosum, 



cut 



Urethra 



Prostate 



Cut edge of visceral layer 

 of pelvic fascia 

 — Cut edge of levator ani 



Cut edge of pelvic fascia 



Seminal vesicle, vas 

 deferens to inner side 



Greater sacro-sciatic 

 ligament 



Rectum, turned back 



Bladder 



Deep dissection of perineum, in ^yhich pelvic floor has been partly removed, exposing bladder. 

 seminal vesicles, spermatic ducts, and prostate ; rectum has been turned back 



tures entmng mto the " permeal centre," the lower portion of the superficial layer 

 of the triangular ligament, the compressor urethrae muscle, the membranous urethra, 

 and the apex of the prostate. The bladder is entered by dilating with the finger the 

 prostatic urethra and vesical neck. The advantages claimed for it are : {a) dimin- 

 ished hemorrhage on account of the relatively slight vascularity of the mid-line ; {b') 

 lessened risk of opening the pelvic fascia ; {c) lessened risk of wounding the ejacu- 

 latory ducts or seminal vesicles. The disadvantages are : {a) the narrow space 

 between the rectum and the deep urethra, exposing the bulb and its arterv to 

 danger anteriorly and the rectum posteriorly ; {b^ the lack of space for the extrac- 

 tion of even moderately large calculi ; (f) the increased risk of pushing the bladder 

 before the finger and tearing it from the urethra. All these objections are much 

 greater in the case of children. 



Suprapubic lithotomy is done by means of an incision in the mid-line imme- 

 diately above the symphysis, dividing skin, superficial fascia, transversalis fascia 



121 



