Preoperative Extraintestinal Manifestations Associated with Chronic Pouchitis in Japanese Patients with Ulcerative Colitis After Ileal Pouch-anal Anastomosis: A Retrospective Study

Background: Pouchitis is a major problem after ileal pouch-anal anastomosis in patients with ulcerative colitis. Chronic pouchitis is particularly troublesome. This study aimed to identify risk factors for the development of chronic pouchitis in a Japanese population. Methods: We retrospectively reviewed 100 patients who underwent pouchoscopy for a functioning ileal pouch. The diagnosis of pouchitis was made according to the modified pouchitis disease activity index. The incidence of pouchitis was estimated using the Kaplan-Meier curve, and Cox regression analysis was used to identify risk factors for the development of chronic pouchitis. Results: Twenty-two patients developed pouchitis; 12 of them had chronic pouchitis. The incidences of chronic pouchitis were 3.3%, 7.6%, and 16.6% at 2, 5, and 10 years, respectively, after the pouch operation. The incidence of pouchitis was significantly higher in patients with preoperative extraintestinal manifestations (EIMs) than in those without (log-rank test, P = 0.002 and P = 0.005 for overall and chronic pouchitis, respectively). Cox regression analysis revealed that the presence of extraintestinal manifestations was an independent risk factor for the development of overall (hazard ratio: 4.48, 95% confidence interval, 1.77-11.30, P = 0.002) and chronic (hazard ratio: 5.81, 95% confidence interval, 1.67-20.23, P = 0.006) pouchitis. Conclusions: The presence of preoperative extraintestinal manifestations was found to be an independent risk factor for the development of overall and chronic pouchitis.