Objective: To evaluate a new surgical procedure, ileoneorectal anastomosis (INRA), in patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP).

Background: Surgical treatment in UC and FAP aims to resect diseased colonic mucosa and restore oroanal continuity. The ileopouch anal anastomosis achieves this but has a 15% to 35% complication rate, a 10% failure rate, and an unpredictable functional outcome. An alternative surgical technique, INRA, has been developed in which the rectal mucosa is replaced by a vascularized ileal mucosa graft.

Methods: Eleven patients underwent an INRA procedure with a temporary diverting ileostomy. Clinical history, repeat endoscopy, histologic examination, and rectal compliance measurements were carried out before and after surgery.

Results: The INRA procedure was technically successful in all patients. Endoscopy showed ingrowth of ileal mucosa in the neorectum, with 100% coverage after 6 weeks. No patient had pelvic sepsis, neorectal-anal or -vaginal fistula, autonomic nerve damage, or fecal incontinence. Neorectal function improved with time. The median 24-hour defecation frequency decreased from 15 (range 9 to 25) to 7 (range 4 to 10) at 11 months follow-up, and the median maximum tolerated volume increased to 157 (range 130 to 225) ml. Anal manometry and electrosensitivity were not affected by the surgery. Histologic biopsy samples after 1 year showed a normal small intestinal mucous membrane, without inflammation or fibrosis.

Conclusions: The combination of a low complication rate and good neorectal function at 1 year is a substantial improvement that justifies extension of the clinical application in patients with UC and FAP.