Risk of dysplasia in long-term ileal pouches and pouches with chronic pouchitis.

BACKGROUND & AIMS: Recent reports have suggested the mucosa of an ileal reservoir could be at risk of neoplasia. Risk factors may include the age of the pouch, chronic pouchitis, and previous colonic neoplasia. This study examined a group of such patients to determine the risk of dysplasia.

METHODS

From a cohort of 1221 patients with ileal pouches, 171 patients with possible risk factors were selected. Successful contact was made with 138 patients who were invited for endoscopy and multiple biopsies. Biopsy specimens were stained with H&E and p53, scored for inflammatory changes including villous atrophy, and analyzed by flow cytometry.

RESULTS

One hundred six patients took part and fell into 1 or more of the following clinical categories: chronic pouchitis (n = 34), pelvic pouch for > or =12 years (n = 42); Kock pouch for > or =14 years (n = 29), and neoplasia in colectomy specimen (n = 11). Thirty-three patients had severe villous atrophy. One patient of 106 (95% confidence interval, 0.9% +/- 1.6%) with a long-standing pouch had low-grade dysplasia that was multifocal. DNA analysis by flow cytometry showed aneuploidy in this patient and 2 others.

CONCLUSIONS

These data suggest that the development of dysplasia in ileal pouches performed for ulcerative colitis is probably a rare event within 15-20 years of pouch surgery.