The rectum represents the last part of the colon and serves as an essential organ for further water withdrawal from the stool and as a reservoir for withholding defecation. Furthermore, it has important functions in maintaing continence function and eliciting the “defecation reflex” which leads to a coordinated emptying of the feces. Removing the rectum by an operation leads to an impairment of this function, but this can be managed by creating an new reservoir from colon (pouch) and preserving the critical transitory area between anal skin and rectal mucosa.
Operations for rectal cancer
High/deep anterior rectal resection, total mesorectal excision (TME)
If the cancer is located in the rectum today in 90% of the cases the anal sphincter muscle and thereby the continence function can be preserved. The successed are further improved by a special safe and prognosis-improving technique the so called “total mesorectal excision”. Some tumors require pretreament with radiochemotherapy due to their position and penetration depth into the rectal wall. During the operation itself the surgeon prepares strictly along the embryonal fascia to prevent local tumor recurrence due to cancer cell spilling. Also in this procedure all lymph node filter stations are removed. The reconstruction is done by connecting the healthy colon and the small rest of the rectum almost at the level of the anal sphincter. Sometimes is can be advantageous to create a colon pouch as a reservoir. In all deep locations of the rectal cancer a protective ileostomy is placed before the anastomosis to „lay dry“ the reconstruction for 3 months to make sure that there is appropriate healing.
Possibilities of complications after removal of the rectum are related to the anstomosis between upper colon and lower remnant of the rectum and/or the anal sphincter muscle. They occur in about 5-8% of the cases however, they remain mostly without consequences if an ileostomy is placed. Furthermore there is the risk of bladder and sexual dysfunction especially in men. Hospitalisiation takes about 8-12 days.