Impact of histologic disease activity on long-term outcomes in patients with ileal pouch-anal anastomosis for ulcerative colitis.

Abstract

Background: Ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) can incur in complications. The impact of histological activity on the development of pouch-related complications is poorly studied.

Aim: To assess the association between histology and long-term outcomes in UC-IPAA.

Methods: Single-center, ambidirectional cohort study including UC-IPAA patients undergoing pouchscopy after ileostomy closure. Histological activity was defined as a Pouchitis Disease Activity Index histology subscore ≥2. The primary outcomes were: (i) development of chronic pouchitis, (ii) need of therapy escalation (azathioprine/biologics), and (iii) a composite outcome of treatment with biologics/azathioprine, pouch-related hospitalization or pouch failure.

Results: A total of 104 patients were included. After pouchoscopy, the median patient follow-up was 2.3 years (IQR, 1.3-4.0). Eighteen patients (17.3 %) developed chronic pouchitis, 20 (19.2 %) initiated biologics/azathioprine, and 25 (24 %) experienced the composite outcome. After adjusting for confounders, histological activity was significantly associated with development of chronic pouchitis (aHR=4.44; 95 % CI, 1.43-13.80; p=0.010), the treatment with biologics/azathioprine (aHR=4.74; 95 % CI, 1.53-14.71; p=0.007), and the composite outcome (aHR=3.94; 95 % CI, 1.53-10.13; p=0.004).

Conclusion: Histological activity is associated with the development of chronic pouchitis and the need for azathioprine/biologics in UC-IPAA patients, highlighting its potential role in guiding long-term management.