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

Background & Aims: Recent reports have suggested the mucosa of an ileal res ervoir could be at risk of neoplasia. Risk factors may include the age of t he pouch, chronic pouchitis, and previous colonic neoplasia. This study exa mined a group of such patients to determine the risk of dysplasia. Methods: From a cohort of 1221 patients with ileal pouches, 171 patients with possi ble risk factors were selected. Successful contact was made with 138 patien ts who were invited for endoscopy and multiple biopsies. Biopsy specimens w ere stained with H&E and p53, scored for inflammatory changes including vil lous atrophy, and analyzed by flow cytometry. Results: One hundred six pati ents took part and fell into 1 or more of the following clinical categories : chronic pouchitis (n = 34), pelvic pouch for greater than or equal to 12 years (n = 42); Kock pouch for greater than or equal to 14 years (n = 29), and neoplasia in colectomy specimen (n = 11). Thirty-three patients had sev ere 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 oth ers. Conclusions: These data suggest that the development of dysplasia in i leal pouches performed for ulcerative colitis is probably is a rare event w ithin 15-20 years of pouch surgery.