Mucosal changes in ileal pouches after restorative proctocolectomy for ulcerative and Crohn's colitis

PURPOSE: inflammation and dysplasia may affect the ileal pouch after restor ative proctocolectomy and ileal pouch-anal anastomosis. The aim of this pro spective study was to evaluate the morphologic changes and the risk of dysp lasia within the pouch after ileal pouch-anal anastomosis. METHODS: Thirty- seven patients with ileal pouch-anal anastomosis underwent endoscopies and biopsies of the pouch: 21 patients were affected by ulcerative colitis and 16 by Crohn's colitis. The mucosal biopsy specimens were studied to investi gate the degree of acute and chronic inflammation and the occurrence of dys plasia. A score system was calculated for each patient and correlated with the histologic diagnosis of ulcerative colitis or Crohn's colitis. RESULTS: After a median follow-up of 85 (range, 7-198) months, the inflammation his tologic score evaluated was 3.8 (95 percent confidence interval, 2.4-5.1) a nd 3.5 (95 percent confidence interval, 2.6-4.3), respectively, in patients with Crohn's colitis and ulcerative colitis (mean and 95 percent confidenc e interval; P = 0.74, not significant), and no patient developed mucosal dy splasia. Fifteen patients (40.5 percent) developed clinical pouchitis that occurred in Crohn's colitis (9/16 patients or 56 percent) and in ulcerative colitis (6/21 patients or 28 percent; P not significant). The score was 4. 1 (95 percent confidence interval, 3.2-5) in patients with pouchitis and 3. 2 (95 percent confidence interval, 2.1-4.3) in patients without clinical po uchitis (P = 0.012) and was 4.1 (95 percent confidence interval, 2.6-5.5) a nd 4.1 (95 percent confidence interval, 2.9-5.3), respectively, in pouchiti s patients with Crohn's colitis and ulcerative colitis. CONCLUSION: No diff erence in the inflammation histologic score was observed in ileal pouches a fter restorative proctocolectomy for ulcerative and Crohn's colitis. In our series, which includes those patients with longer follow-up (>5 years) or with chronic unremitting pouchitis, no case of dysplasia was found. The occ urrence of pouchitis was higher in the case of ileal pouch-anal anastomosis for Crohn's disease than for ulcerative colitis, but no difference in the severity of the histologic score was noted.