THE PKOSTATE. 1429 



become visible through the mucous membrane. When the bladder is hyper- 

 trophied as the result of, urinary obstruction the muscular trabeculse become 

 greatly hypertrophied, and stand out prominently, even when the bladder is full. 

 The spaces between the trabeculse may become so deeply pitted as to lead to the 

 formation of little pockets, known as false diverticula. 



THE PROSTATE. 



The operation of prostatectomy has proved so successful in removing 

 urinary complications associated with enlargement of the prostate that a fresh 

 impetus has been given to the study of the anatomy of the gland from the surgical 

 point of view. With the body erect the base of the prostate lies in a horizontal plane 

 at the level of the middle of the symphysis pubis, while its apex lies \ in. behind 

 and below the sub-pubic angle. It follows, therefore, that the vesical orifice and 

 the base of the prostate are within easy reach of the finger introduced through a 

 supra-pubic cystotomy incision. The anterior surface of the prostate lies about 

 | in. behind the pubes, to which it is connected by the pubo-prostatic ligaments. 

 Above those ligaments is the space of JRetzius, occupied by fatty tissue which 

 passes upwards in front of the anterior wall of the bladder, between the umbilical 

 arteries, as far as the umbilicus, while laterally it extends on each side, between the 

 peritoneum and pelvic fascia, as far back as the hypogastric arteries. The 

 posterior surface of the prostate is related to that part of the rectal ampulla 

 immediately above the anal canal, and is therefore accessible to palpation per 

 rectum. Between the rectum and the posterior part of the sheath of the prostate 

 (formed by the recto-vesical layer of pelvic fascia) is a loose cellular interval, which 

 is taken advantage of in the operation of excision of the rectum, and in exposing 

 the posterior surface of the prostate in the operation of perineal prostatectomy. 

 The lateral surfaces of the prostate cannot be felt through the rectum ; they are 

 related to the anterior or pubo-rectal fibres of the levatores ani, from which they 

 are separated by the lateral portion of the fascial envelope of the gland. 



The prostate substance is made up of branching tubular glands supported 

 by a fibro-muscular stroma. The gland tissue is most abundant in the posterior 

 and lateral aspects of the organ ; anteriorly the stroma is more abundant and 

 extends backwards from the capsule to the urethra to form a sort of anterior 

 commissure. By the term " capsule " of the prostate is understood the immediate 

 or proper envelope of the gland ; this envelope consists of parallel layers of fibro- 

 muscular tissue, continuous with, and forming part of, the stroma of the organ. In 

 some instances it is so thin that the gland tissue reaches almost to its surface, 

 while in other instances it is so thick as to deserve to be regarded as forming the 

 cortical portion of the gland. By the term " sheath " of the prostate is meant the 

 fibrous envelope derived from the pelvic fascia ; the veins of the pudendal plexus 

 lie between its lamellae. 



In what is known as " senile " hypertrophy of the prostate the organ may be uniformly 

 enlarged, or the enlargement may affect chiefly one or other of the lateral lobes, one 

 or both of which may enlarge more particularly in an upward direction so as to project 

 into the bladder. This intra-vesical overgrowth may take the form either of a more or 

 less pedunculated projection, situated immediately behind the internal urethral orifice, or it 

 may surround the orifice to form a prominent ring-like elevation. As the intra-vesical 

 growth enlarges, it makes its way towards the bladder within the ring of the sphincter 

 vesicae, and, having pushed before, or separated, the internal longitudinal fibres of the 

 bladder, it comes ultimately to be separated from the cavity of the bladder by mucous 

 membrane only. In the operation of supra-pubic prostatectomy the true capsule of the 

 prostate is at once reached by simply tearing through the mucous membrane immediately 

 behind the vesical orifice. By keeping close to the capsule, the entire organ, including the 

 capsule, may be enucleated from its sheath. As the latter is markedly thicker and denser 

 in the liypertrophied than in the normal prostate, this enucleation can be accomplished 

 without injuring the veins of the pudendal plexus. As a rule, the only part where any 

 difficulty in the enucleation is encountered is anteriorly, where the capsule is more 

 intimately connected with the sheath by the interposition of a layer of striated longi- 

 tudinal muscular fibres which pass from the urethra to be continuous with the outer 



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