932 



PERINEUM. 



usually failed, for so deeply do the pudic vessels 

 run, and so firmly bound down are they by the 

 triangular ligament and the obturator fascia, 

 that the ligature, as commonly applied, has 

 proved useless in the hands of even the most 

 dexterous surgeons. The open mouth of the 

 artery may, however, in such cases be often 

 secured by the aid of a curved needle carried 

 deeply into the wound, and some practitioners 

 (amongst the number M. Roux)have succeeded 

 by the same means in tying the pudic artery 

 itself in the vicinity of the tuber ischii, a pro- 

 ceeding attended with complete success. The 

 judicious application of pressure to the bleeding 

 point by an apparatus so constructed as to plug 

 the wound at the same time that it permits the 

 urine to escape freely, has been also followed by 

 satisfactory results. The same principles of 

 treatment are applicable to hemorrhage from 

 accidental wounds of the arteries of the bulb in 

 lithotomy. 



On dividing the triangular ligament of the 

 urethra the dissector arrives at the deep com- 

 partment of the anterior division of the peri- 

 neum, but to examine its contents with advan- 

 tage he requires a section of the pelvis, such as 

 that advised in a former part of this article. 

 This compartment is limited superiorly or 

 towards the abdomen by the recto-vesical 

 layer of the pelvic fascia; inferiorly or towards 

 the surface by the back of the triangular liga- 

 ment of the urethra ; and posteriorly by the 

 rectum ; its shape is somewhat triangular, and 

 it contains Wilson's muscles, many fibres of the 

 levatores ani, a part of the membranous por- 

 tion of the urethra, the prostate gland, a plexus 

 of veins excessively developed in some sub- 

 jects, and at times also an irregular artery justly 

 dreaded by the lithotomist. 



Wilson's muscles (the compressores urethra) 

 are two triangular fleshy fasciculi, which arise 

 from the back of the symphysis pubis, each by 

 a narrow tendon ; their point of attachment is 

 about one-eighth of an inch beneath the ante- 

 rior true ligament of the bladder, and the same 

 distance above the lower margin of the cartila- 

 ginous arch of the pubis. The two muscles, 

 expanding as they descend, separate from each 

 other at the membranous portion of the urethra, 

 and passing one on each side of that part of the 

 canal they again unite beneath it in a sort of 

 tendinous raphe, which extends from the pros- 

 tate gland to the bulb; many of their fibres may 

 be likewise traced to the central tendinous point 

 of the perineum. A cellular interstice inter- 

 venes between the two muscles at their origin, 

 and from the levatores ani they are separated at 

 each side respectively by cellular tissue and 

 some small veins. Wilson's muscles may ele- 

 vate and compress the urethra so as to close 

 the canal; their influence in catheterism is 

 decided and has been already discussed; one 

 of them, the left, is divided in the lateral, and 

 both are cut in the bilateral operation of litho- 

 tomy. In some subjects Wilson's muscles are 

 absent, or rather they are inseparable from the 

 levatores ani ; but in such cases the anterior 

 fibres of these latter muscles surround the ure- 

 thra, perform all the offices assigned to the 



compressores urethra, and are similarly circum- 

 stanced as regards operations on the perineum. 



The recto-urethral space, but partially seen 

 so long as the triangular ligament of the urethra 

 remains in situ, becomes fully exposed after 

 the division of that fibrous septum. This 

 space results from the inclination backwards 

 of the lower extremity of the rectum, whilst 

 the urethra inclines forwards through the arch 

 of the pubis; its form is triangular, the base 

 at the integuments of the perineum, the apex 

 at the prostate gland, the membranous and the 

 bulbous portions of the urethra constituting its 

 anterior wall, and the rectum bounding it pos- 

 teriorly. In cutting from the integuments to 

 the urethra through the recto-urethral triangle, 

 the anatomist encounters, first, the superficial 

 perineal fascia; next, the extremities of the 

 several muscles which meet and are confounded 

 with each other at the central tendinous point 

 of the perineum, and also the small arterial 

 anastomosis situated in the same locality, still 

 deeper the peaked prolongation of the trian- 

 gular ligament ; and, lastly, Wilson's muscles 

 at their junction beneath the urethra. 



The membranous portion of the urethra is 

 situated within ten lines of the rectum, and the 

 bulb projects still further backwards, lying but 

 half an inch apart from that, intestine, so that, 

 in the lateral and also in the bilateral operations, 

 the lithotomist incurs some risk of wounding 

 the bowel as he lays bare the groove in the 

 staff. In the bilateral method the operator 

 endeavours, by a semilunar incision carried 

 across the recto-urethral triangular space, to 

 reach the staff as it lies in the membranous 

 portion of the urethra, and from the proximity 

 of the bulb to the rectum both these parts are 

 endangered as the knife traverses the interme- 

 diate space. In the lateral method the rectum 

 is not so likely to be injured in the correspond- 

 ing step of the operation, because the bowel is 

 further removed from the membranous portion 

 of the urethra than from the bulb, and besides 

 the urethra is incised somewhat upon its lateral 

 aspect. In either case the surgeon best ensures 

 the safety of the intestine by taking care to have 

 the faeces evacuated before the operation com- 

 mences, by holding the staff well up into the 

 arch of the pubis, and by directing the point of 

 the knife forwards as he cuts into the urethra. 



The recto-urethral triangular space is the po- 

 sition usually occupied by that rare form of 

 rupture, a perineal hernia; in this disease the 

 hernia leaves the abdominal cavity at the bottom 

 of the great cul-de-sac of the peritoneum, and 

 drawing down the serous membrane in its pro- 

 gress it gradually insinuates itself between the 

 prostate gland and the rectum, and at length 

 protrudes between the rectum and the bulb. 

 In the perineum the sac is in general rather su- 

 perficial. The tumor occasionally deviates 

 from the middle line, and projects outwards 

 and backwards behind the transversus perinei 

 muscle into the ischio-rectal fossa ; it rarely 

 undergoes strangulation, being in almost every 

 instance reducible. 



The prostate gland demands the special at- 

 tention of the surgical anatomist, for much of 



