1692 HUMAN ANATOMY. 



If it spreads to distant parts, it should be remembered that, if it is high and fol- 

 lows lymphatic channels, it involves first the sacral glands in the sacral curve and 

 then the lumbar glands by the sides of the lumbar vertebrae. The former, when 

 much enlarged, may be felt with the finger in the rectum. The latter are palpable 

 through the anterior abdominal wall. If the carcinoma is at or near the anus, the 

 upper inguinal glands are apt to be first involved. If it spreads through the blood- 

 vessels, it may, whatever its seat, follow the superior hemorrhoidal veins to the portal 

 system and the liver or the internal pudic and iliac veins to the vena cava and to the 

 lungs and elsewhere. 



The 7'elatio7is of the rectum are of much practical importance. Those with the 

 peritoneum have been described (page 1753). The fact that this membrane leaves 

 the rectum uninvested posteriorly makes it possible in rectal cancer to remove safelv 

 more of the posterior than of the other walls. Penetrating ulcers are more apt to 

 involve the peritoneal cavity if on the anterior wall. 



In the male the rectum is in relation anteriorly to the prostate, the seminal vesi- 

 cles, and the base of the bladder. Dilatation of the rectum raises the recto-vesical fold 

 of peritoneum and elevates and advances the bladder, bringing a larger non-peritoneal 

 surface in closer contact with the abdominal wall. This is sometimes made use of 

 in suprapubic lithotomy or prostatectomy {q.v.). In the female rectal distention 

 pushes the fundus uteri upward and towards the pubes. 



Injuries to the rectum are dangerous, aside from shock and hemorrhage, on 

 account of the risks of septic peritonitis or cellulitis. The height of the wound or 

 rupture or perforation and its relation to the peritoneal pouch or to the recto-vesical 

 fascia are of great importance. The rectum is less liable to direct trauma than are 

 other portions of the intestinal tract, on account of the protection afforded it by the 

 bony walls of the pelvis. 



Enlargement of the prostate may so depress the anterior wall of the rectum as 

 greatly to diminish its lumen. Occasionally symptoms of rectal obstruction are 

 produced thereby. Acute prostatic inflammation and prostatic abscess may be 

 recognized by rectal touch, as may similar conditions of the seminal vesicles. They 

 are, for obvious reasons, apt to be associated with rectal irritation, tenesmus, and 

 painful defecation. 



In operations on the rectum, as for excision of carcinoma, it may be approached 

 {a) from belozv, when the disease is near the anus, by isolating the lower end of the 

 gut. If the anus is involved, the incision may be made outside the external sphinc- 

 ter ; if not, the incision may follow the ' ' white line. ' ' It will be necessary to divide 

 the lateral fascial attachments, the levator ani on each side, the connective tissue 

 between the rectum and vagina or rectum and urethra and prostate, and numerous 

 hemorrhoidal branches, {b) It may be approached from above, when the growth is 

 high, by opening the peritoneal cavity. The sigmoid may also be opened, the dis- 

 eased segment of gut invaginated into it and excised, and the remainder of the 

 rectum and sigmoid united (Maunsell). {c) It may be reached from in front 

 through a median incision in the posterior wall of the vagina ; or (^ ) from behind 

 by removal of the coccyx ; or, if more room is required, by detachment of the sacro- 

 sciatic ligaments ; or, in still more extensive disease, by resection (osteoplastic or 

 otherwise:) of the left half of the sacrum up to the level of the lower border of the 

 third sacral foramen. Paralysis of the bladder may follow interference with the third 

 sacral nerve. The sacral and coccygeal attachments on the left side of the levator 

 ani, the coccygeus, and the sacro-sciatic ligaments must, of course, be divided, as 

 must the fourth and fifth sacral and the coccygeal nerves. The lateral and median 

 sacral arteries and their accompanying veins are raised, with the fibrous tissue on 

 which they lie, from the anterior surface of the sacrum by a blunt elevator. 



Examiriation per rectum may be made by the finger, by inspection, by bougies, 

 or by the introduction of the whole hand. 



{a) With \.\\Q Jin^er one can feel the involuntary contraction of the sphincters 

 embracing the finger for the space of about an inch. If the patient is asked to con- 

 tract the sphincter voluntarily, the levator ani will participate, as both muscles are 

 innervated by the fourth sacral nerve. As a result of this, the upper margin of the 

 contracted portion — i.e., of the anal canal — will then be felt to "end abruptly and 



