Background
The ileal pouch–anal anastomosis (IPAA) is a surgical procedure that is used to restore gastrointestinal continuity after surgical removal of the colon and rectum. [1] Various conditions, including inflammatory states, cancer, or infection, may necessitate the complete surgical removal of the colon and rectum.
Also called a J pouch or an internal pouch, the procedure involves the creation of a pouch of small intestine to recreate the removed rectum. Two or more loops of intestine are sutured or stapled together to form a reservoir for stool. This reservoir is then attached to the anus for reestablishment of anal fecal flow. The IPAA is often protected by temporarily diverting the path of stool through the abdominal wall in the form of an upstream ileostomy. After a period of recovery, this ileostomy is reversed during a separate procedure.
Indications
The IPAA procedure is performed after the colon and rectum have been completely removed. Removal of the colon and rectum is termed proctocolectomy. When an IPAA follows, the procedure is called a restorative proctocolectomy. [2] Indications for restorative proctocolectomy include the following [3] :
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Certain cancers, such as those associated with hereditary nonpolyposis colorectal cancer
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Disorders of excessive colonic polyps, including familial adenomatous polyposis
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Toxic megacolon from infectious causes
Contraindications
Creation of a J pouch is contraindicated when the small bowel is involved in the disease process. Such involvement is most common when proctocolectomy is performed for Crohn disease, because the distal ileum is often affected. IPAA is also contraindicated when the distal rectum or anal canal is diseased, as with Crohn disease or rectal cancer.
Concerns have been expressed about the safety of IPAA in older patients. A systematic review by Ramage et al found that the procedure was safe in this population, provided that the increased risk of dehydration and electrolyte loss was kept in mind. [4] Older IPAA patients appeared to have worse postoperative function, but this impaired function seemed to level out over time, and there appeared to be no significant impact on overall quality of life and patient satisfaction.
Technical Considerations
Complication prevention
Several standardized practices are followed to decrease the incidence of perioperative complications. Antibiotics are given within 1 hour of surgery to lower the rate of wound infection. Compression devices are placed on the legs to decrease the likelihood of blood clot formation. Patients are typically asked to stop taking any antiplatelet agents (eg, aspirin or clopidogrel) 1 week prior to surgery. This reduces bleeding complications.
Finally, before starting the surgical procedure, the surgeons, operating room staff, and anesthesia team should verify the correct patient and procedure in order to prevent errors.
Outcomes
In a systematic review with meta-analysis and metaregression (11 studies; N = 6770), Pellino et al evaluated the outcome of IPAA for Crohn disease (n = 352) against that for ulcerative colitis (n = 6418). [5] They found that patients with Crohn disease had a fivefold higher risk of failure and a twofold higher risk of strictures after IPAA than patients with ulcerative colitis. Function in Crohn patients who retained the pouch was similar to that in ulcerative colitis patients. Crohn disease did not increase the risk of pouchitis. The authors concluded that IPAA could be offered to selected Crohn patients after appropriate preoperative counseling.
In a systematic review and meta-analysis (six retrospective studies; N = 3460), Emile et al compared IPAA outcome of IPAA in patients with obesity and patients with ideal weight. [6] They found that obese patients who underwent IPAA were more likely to have open (rather than laparoscopic) procedures; a longer operating time; greater blood loss; higher rates of complications, anastomotic leakage, and incisional hernia; and longer hospital stays.
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Ileal pouch-anal anastomosis.
