THE PEOSTATE. 1433 



In the child rectal examination enables one to palpate, in addition to the structures in the 

 cavity of the pelvis minor, those which occupy the lower segment of the abdomen. When 

 the bladder is empty even a small calculus can be readily felt by recto-abdominal palpation. 



The distance of the apex of the recto-vesical pouch of peritoneum from the anus 

 varies considerably, according to the degree of distension of the bladder and rectum ; 

 when both are empty it reaches to about 2 in. from the anus ; when both are dis- 

 tended it is at least one inch higher (Fig. 1108). 



Examination by Sigmoidoscope. In introducing the sigmoidoscope into 

 the pelvic colon the direction of the anal canal and the curve of the rectum must 

 be borne in mind ; as the instrument traverses the anal canal it must be directed 

 forwards as well as upwards, after which it is pushed onwards, in a backward and 

 upward direction, towards the hollow of the sacrum ; while, finally, in order to 

 reach the pelvic colon, it is again directed forwards and a little to the left so as to 

 clear the promontory of the sacrum. The instrument is more difficult to pass in 

 women, on account of the greater abruptness of the curvature of the sacrum in the 

 female as compared with the male. 



When examined with the sigmoidoscope the mucous membrane of the rectum 

 is seen to possess a deep red colour, and an excellent view is obtained of the rectal 

 valves of Houston. The most conspicuous fold, known as the plica transversalis, 

 projects from the right wall about the level of the recta-vesical peritoneal 

 reflection, i.e. about three inches from the anus. The highest valve, situated at 

 the colo-rectal junction, gives rise to a distinct narrowing which must not be 

 mistaken for a stricture. The pulsations of the left common iliac artery can 

 generally be seen to be communicated to the postero-lateral wall of the pelvic colon 

 about four inches from the anus. 



Removal of the Rectum. In removing the rectum and anal canal for 

 malignant disease, an incision is carried round the anus and then upwards and 

 backwards over the coccyx and inferior half of the sacrum. The ano-coccygeal 

 raphe is divided longitudinally and the coccyx (either alone or along with more or 

 less of the lower part of the sacrum) is excised by dividing the structures 

 attached to its margins, viz., the inferior fibres of the glutseus maximus, the 

 coccygeus, and the sacro-tuberous and sacro-spinous ligaments (O.T. greater and 

 lesser sacro-sciatic). The parietal pelvic fascia, here very thin and adherent, is 

 removed along with the bone. The middle sacral artery is ligatured. This is now 

 seen, stretching across the floor of the wound, a well-defined sheet of fascia, viz., 

 the rectal layer of the visceral pelvic fascia, which is divided longitudinally and 

 stripped to either side off the posterior surface of the rectum ; in doing this the 

 branches of the middle hsemorrhoidal arteries, and, higher up, the two divisions of 

 the superior haemorrhoidal are encountered and ligatured. Anteriorly, the anal 

 canal is detached from the central point of the perineum, after which the anterior 

 surface of the rectum is freed from below upwards from the urogenital 

 diaphragm containing the membranous urethra, the posterior surface of the 

 prostate, the trigone of the bladder and the vesiculae seminales and the ductus 

 deferentes. This procedure is facilitated by the existence of a cellular interval 

 between the anterior wall of the rectum and the strong recto-vesical layer of 

 visceral pelvic fascia, which forms the posterior part of the sheath of the prostate, 

 and, higher up, encloses the vesiculse seminales and ductus deferentes. In order 

 to strike this cellular interspace, the surgeon, after dividing the central point of 

 the perineum transversely, deepens the incision down to the apex of the prostate. 

 In doing this he divides a band of muscular fibres (recto-urethral muscle) which 

 passes from the anterior wall of the lowest part of the rectal ampulla to blend 

 with the sphincter ure three muscle surrounding the urethra at the apex of the 

 prostate. It is these recto-urethral fibres, which, by pulling forwards the ampulla, 

 bring it into close relation with the urethra ; hence it is especially at this stage of 

 the operation that great care must be taken not to open into the rectum or to 

 wound the urethra. After exposing the apex of the prostate the next step is to 

 retract the anal canal well backwards and to define the anterior of pubo-prostatic 

 borders of the levator ani muscle. These muscles are then divided, on each side, 



