Pouch functional outcomes after restorative proctocolectomy with ileal-pouch reconstruction in patients with ulcerative colitis: Japanese multi-center nationwide cohort study

Background: Although several complications capable of causing pouch failure may develop after restorative proctocolectomy (RPC) for ulcerative colitis (UC), the incidences and causes are conflicting and vary according to country, race and institution. To avoid pouch failure, this study aimed to evaluate the rate of pouch failure and its risk factors in UC patients over the past decade via a nationwide cohort study. Methods: We conducted a retrospective, observational, multicenter study that included 13 institutions in Japan. Patients who underwent RPC between January 2005 and December 2014 were included. The characteristics and backgrounds of the patients before and during surgery and their postoperative courses and complications were reviewed. Results: A total of 2376 patients were evaluated over 6.7 ± 3.5 years of follow-up. Twenty-seven non-functional pouches were observed, and the functional pouch rate was 98.9% after RPC. Anastomotic leakage (odds ratio, 9.1) was selected as a risk factor for a non-functional pouch. The cumulative pouch failure rate was 4.2%/10 years. A change in diagnosis to Crohn’s disease/indeterminate colitis (hazard ratio, 13.2) was identified as an independent risk factor for pouch failure. Conclusion: The significant risk factor for a non-functional pouch was anastomotic leakage. The optimal staged surgical procedure should be selected according to a patient’s condition to avoid anastomotic failure during RPC. Changes in diagnosis after RPC confer a substantial risk of pouch failure. Additional cohort studies are needed to obtain an understanding of the long-standing clinical course of and proper treatment for pouch failure.