1430 SUKFACE AND SUKGICAL ANATOMY. 



longitudinal fibres of the bladder. In " total " prostatectomy, practically the whole of 

 the prostatic urethra is removed along with the gland. In some instances, instead of 

 removing the entire prostate and its capsule along with the prostatic urethra, the surgeon, 

 by working within the capsule, is able to enucleate each lateral glandular mass either 

 separately or united to its fellow in the form of a horse-shoe shaped mass, the urethra 

 and the anterior commissure being left more or less intact. The cavity, which is left 

 behind after the removal of the prostate, at once contracts owing to the approximation of 

 the bladder and rectum antero-posteriorly, and of the levatores ani at the sides. 



In perineal prostatectomy the posterior surface of the prostate is exposed by making a 

 horse-shoe shaped incision with the convexity reaching forwards to a point immediately 

 behind the bulb ; at the sides, the incision sinks into the ischio-rectal fossae, its extremities 

 ending at the anterior part of the ischial tuberosities (Fig. 1108). After reflecting the skin 

 and subcutaneous tissue, the incision is carried through the central point of the perineum. 



The bulb, the superficial transverse perineal muscles, and the inferior fascia of the 

 urogenital diaphragm are now drawn forwards, and the fibres of the recto-urethral 

 muscle (which connect the anterior wall of the rectal ampulla with the sphincter 

 urethrse) are divided ; this allows the anal canal and the inferior end of the rectum to be 

 retracted backwards. The dissection is now carried in a forward direction, between 

 the anterior borders of the levatores ani, towards the prostate, so as to strike the loose 

 non-vascular space which intervenes between the posterior part of the prostatic sheath and 

 the thin fascia outside the muscular wall of the rectum. The posterior surface of the 

 prostate, covered by its true capsule, is reached by incising the fascial sheath. The 

 prostate, along with its true capsule and the urethra, may either be enucleated entire 

 from the sheath, or the true capsule may be incised as well as the sheath, and the 

 adenomatous masses removed separately. The operation is greatly facilitated by pulling 

 the prostate down into the wound by a special retractor (Young) inserted into the bladder 

 through a median incision into the floor of the membranous part of the urethra. 



The epididymis, which can be felt, as an elongated curved body applied 

 vertically to the posterior margin of the testis, is especially involved in gonorrhoaal 

 and tubercular infections of the testis. Occupying the posterior part of the 

 spermatic funiculus is the ductus deferens, which, when grasped between the 

 finger and thumb, feels like a piece of whip-cord. The spermatic veins form a 

 plexus in the substance of the funiculus, known as the pampiniform plexus ; a varicose 

 condition of these veins gives rise to the condition known as varicocele. In operating 

 for varicocele the veins are reached by dividing, in succession, all the coverings of 

 the funiculus ; the deepest covering, viz., the internal spermatic fascia, derived from 

 the fascia ( transversalis, forms a well-marked fibrous envelope which immediately 

 surrounds the veins and other constituents of the funiculus. Besides the internal 

 spermatic artery, the testis receives its blood supply from the artery accompanying the 

 ductus deferens and from the external spermatic branch of the inferior epigastric. 



The marked swelling which attends cedema and hcematoma of the scrotum is due 

 to the loose and delicate character of the cellular tissue which occupies the space 

 between the dartos muscle and the subjacent membrane derived from the inter- 

 columnar fascia. 



The anus is situated in the rectal division of the perineum about 1 J in. in front 

 of and below the tip of the coccyx. The skin around the orifice is pigmented and 

 thrown into radiating folds. The painful linear crack or ulcer, known as fissure of 

 the anus, generally occupies one of the furrows at the posterior margin of the 

 anus. The skin of the anus is provided with large sebaceous and sweat glands, 

 which are occasionally the site of small and very painful anal abscesses. 



On making a rectal examination it will be observed that the finger, before it 

 reaches the cavity of the rectum, traverses the narrow or sphincteric portion of the 

 rectum, appropriately named by Symington the anal canal. This canal, which is 

 directed from below upwards and forwards, extends from the anal orifice to the I 

 ampulla of the rectum ; it is from one to one and a half inches in length ; its 

 upper end is on a level with the medial borders of the pubo-rectal portions of the - 

 levatores ani. 



External haemorrhoids are developed from the anal folds situated outside the 

 white line corresponding to the muco-cutaneous junction; internal piles are 

 developed from the veins of the mucosa at the upper part of the anal canal. 



