Assessment of the mucosa of the indefinitely diverted ileo-anal pouch

One surgical option to treat failure after restorative proctocolectomy (RPC) is indefinite diversion (ID) without excision of the pouch. The study aimed to assess the mucosal morphology of the pouch and ileoanal anastomosis (IAA) over time after ID with particular reference to inflammation, dysplasia and carcinoma.

Patients with ID were identified from the hospital's Ileal Pouch Database. Individuals were invited by mail to attend for flexible pouchoscopy and biopsy from the ileal pouch and immediately distal to the IAA.

Of 1822 patients on the database, 28 had undergone ID. Of these, 20 patients (18 ulcerative colitis, one familial adenomatous polyposis, one pseudo-obstruction) of median age 42 (18-67) years took part. There were eight males. The median (range) intervals from diagnosis of primary disease, pouch surgery and ID to the time of study were 221 (63-410), 146 (31-314) and 44 (10-159) months respectively. One patient had dysplasia in the original resection specimen. Five patients developed type C changes in the pouch. Of these three were identified between RPC and ID, one developed between ID and the present assessment and one was identified for the first time at the present assessment. No case of dysplasia or cancer was found in any of the biopsies. Rectal mucosa was found in biopsies from the IAA in four patients (three stapled; one handsewn); this was inflamed in three patients.

At a median follow-up of 12 years after RPC and 3.6 years after indefinite diversion no instance of dysplasia or carcinoma in the ileal reservoir or distal to the IAA was found in any of the 20 patients having ID. Type C changes occurred at some time in five (25%) patients, indicating the importance of continued follow up.