Ileoanal Reservoir Surgery Health Article

Definition

Ileoanal reservoir surgery or ileoanal anastomosis is a two-stage restorative procedure that removes a part of the colon and uses the ileum (a section of the small intestine) to form a new reservoir for waste that can be expelled through the anus. This surgery is one of several continent surgeries that rely upon a newly created pouch to replace the resected colon and retain the patient's sphincter for natural defecation. Ileoanal reservoir surgery is also called a J-pouch, endorectal pullthrough, or pelvic pouch procedure.

Purpose

A number of diseases require removal of the entire colon or parts of the colon. Proctolectomies (removal of the entire colon) are often performed to treat colon cancer. Another surgical option is the creation of an ileoanal pouch to serve as an internal waste reservoir—an alternative to the use of an external ostomy pouch. An ileoanal reservoir procedure is performed primarily on patients with ulcerative colitis, inflammatory bowel disease (IBD), familial polyposis, or familial adenomatous polyposis (FAP), which is a relatively rare cancer that covers the colon with 100 or more polyps. FAP is caused by a gene mutation on the long arm of human chromosome 5. Ileoanal reservoir surgery is recommended only in those patients who have not previously lost their rectum or anus.

Demographics

The prevalence of familial adenomatous polyposis (FAP) in the United States is two to three cases per 100,000 persons. It develops before age 40 and accounts for about 0.5% of colorectal cancers; this figure is declining, however, as more at-risk families are undergoing detection and prophylactic colon surgery. The annual incidence of ulcerative colitis is 10.4–12 cases per 100,000 people. The prevalence rate is 35–100 cases per 100,000. People of Jewish descent have two to four times the risk of developing ulcerative colitis than people from other ethnic backgrounds. About 20% of ulcerative colitis patients require surgery of the colon.

Description

Conventional ileoanal reservoir surgery is an open procedure that is done in two stages. In the first stage, the surgeon removes the diseased colon and creates a pouch. The second stage is performed three months later, when the temporary drainage conduit is closed and the newly created reservoir allows the patient to defecate in the normal fashion. Both surgeries can also be done together, bypassing the creation of a temporary ileostomy.

Some surgeons use a laparoscopic approach to ileoanal surgery. This technique involves the insertion of scaled-down surgical instruments and a scope that allows the surgeon to see inside the abdomen through several relatively small incisions (3.5 inches [9 cm] or about compared to 6.3 inches [16 cm] or for an open procedure) in the abdominal wall. Studies indicate that there are few differences in the rates of mortality or complications between laparoscopic surgery and conventional open surgery. Because the incisions are smaller, patients typically require less pain medication with laparoscopic surgery.

Ileoanal surgery includes the following steps:

• The surgeon isolates the ileum or small segment of bowel.
• The segment is then attached to the anus with absorbable sutures.
• A pouch is created out of the small bowel above the anus.
• If the surgeon is performing the procedure in two stages, he or she creates a temporary ileostomy. An ileostomy is a tubular bowel segment attached to a stoma at the abdomen that drains into a bag outside the abdomen.
• In the second-stage operation, the surgeon uses an open abdominal procedure to close the temporary pouch.

The surgeon will insert stents to bypass the surgical site and divert urinary and digestive wastes to the outside of the body, thus allowing the new connection between the ileum and the anus to heal properly.