THE PELVIS 367 



is now only fixed by the distal end of the prostatic urethra, 

 and this is torn across as it pierces the urogenital diaphragm. 



If the surgeon fails to define the interval between the capsule 

 and the sheath and penetrates the latter with his finger-nail, 

 severe haemorrhage results from the thin-walled veins of the 

 pudendal plexus and its vesical tributaries. The condition is 

 accentuated if the surgeon continues to attempt enucleation 

 with his finger in the wrong stratum. 



b Drainage is obtained by a wide supra-pubic tube, but in the 

 presence of cystitis some surgeons make use of a perineal drain 

 in addition. A pair of long forceps is inserted through the 

 supra-pubic wound into the cavity of the prostatic sheath and 

 cut down on in the perineum. A tube is then drawn upwards, 

 and the whole cavity can be washed out thoroughly. An 

 advantage of this additional drain is that it prevents absorption 

 from the accumulation of septic urine and blood-clot in the raw 

 area. 



As a result of the removal of the prostate, the first part of 

 the urethra is replaced by a fibrous sac the prostatic sheath. 

 The neck of the bladder opens into it above and the urethra 

 opens out from it below. This cavity soon collapses and its 

 walls gradually become lined by mucous membrane, which grows 

 upwards from the torn urethra and downwards from the bladder. 



The Seminal Vesicles lie obliquely on the basal surface of 

 the bladder their upper extremities are widely separated and 

 their lower extremities are close together. Posteriorly, they 

 are related to the anterior surface of the rectum, and only 

 visceral pelvic fascia intervenes. The upper, blind end of the 

 seminal vesicle lies immediately under the floor of the recto- 

 vesical peritoneal fossa and close to the termination of the 

 ureter. Its lateral border is closely applied to the medial 

 aspect of the posterior pedicle of the bladder, and its medial 

 border is related to the ductus deferens (Fig. in). 



Inferiorly the seminal vesicle narrows to form the excretory 

 duct, which joins the ductus deferens to form the common 

 ejaculatory duct. The two ejaculatory ducts pass downwards 

 and forwards through the substance of the prostate and open 

 into the prostatic urethra close to the orifice of the prostatic 

 utricle (p. 383). 



The Rectum begins opposite the third piece of the sacrum 

 as the direct continuation of the descending limb of the pelvic 

 colon. It is about five inches long and curves downwards and 



