Predictors of ileal pouch–anal anastomosis failure in ulcerative colitis: a European tertiary referral center experience

BACKGROUND: Total proctocolectomy with ileal pouch-anal anastomosis serves as the standard surgical treatment for medically refractory ulcerative colitis, yet long-term pouch failure remains a significant clinical challenge. This study aimed to identify independent predictors of pouch failure and to develop a practical clinical nomogram for individualized risk assessment. METHODS: A retrospective cohort study was conducted utilizing a prospectively maintained database at a European tertiary referral center, analyzing procedures performed between December 2005 and June 2025. The study included 851 adult patients with a confirmed histologic diagnosis of ulcerative colitis who underwent restorative surgery. The primary outcome was pouch failure, defined as permanent pouch excision or indefinite fecal diversion. Independent predictors were identified using penalized logistic regression modeling to build a predictive risk tool. RESULTS: Over a median follow-up of 37.0 months for the entire cohort, pouch failure occurred in 4.7% of patients (n = 40). Among patients who experienced pouch loss, the median time to failure was 29.4 months. The majority of these failures manifested after 12 months and were primarily driven by severe fistulae and chronic leaks. Preoperative biologic therapy emerged as the sole independent predictor of pouch failure. Handsewn anastomoses and non-standard pouch configurations also demonstrated strong associations with failure. A five-variable clinical nomogram was constructed to provide individualized failure probabilities. CONCLUSION: While overall pouch failure rates remain low in specialized centers, exposure to preoperative biologic therapy significantly elevates this risk. The newly developed nomogram provides a valuable, evidence-based tool for tailored surgical counseling and personalized patient management.