IMPACT OF BARIATRIC SURGERY ON ILEAL POUCH ANAL ANASTOMOSIS OUTCOMES: A SINGLE-CENTER EXPERIENCE

Abstract BACKGROUND Ileal pouch anal anastomosis (IPAA) is the standard procedure for patients with medically refractory ulcerative colitis (UC). Obesity has been associated with an increased risk of peri-operative complications as well as worse functional outcomes and quality of life following IPAA. Studies have shown bariatric surgery (BS) may have a positive impact on IBD outcomes. Given the limited data on the impact of BS in patients with IPAA, we reviewed our center’s experience. METHODS We performed a retrospective study including patients with IPAA and BS (sleeve gastrectomy [SG] and Roux-en-Y gastric bypass [RYGB]) between January 1992 to January 2025. Relevant demographic and clinical data were abstracted. Pouch function after bariatric surgery was evaluated based on the clinical portion of the modified pouchitis disease related activity (mPDAI), average daily stool frequency (SF), pouch-related complications, and use of antibiotics or advanced therapies. Obesity outcomes were evaluated using weight and body mass index (BMI). RESULTS Five patients with IPAA who underwent BS (3 RYGB, 2 SG) were identified, (80% female). Additional demographics are highlighted in Table 1. One patient underwent BS following subtotal colectomy for UC, to lose weight prior to IPPA. Median baseline BMI and weight at the time of BS was 41.0 kg/m2 (interquartile range [IQR], 38.4-49.5) and 118 kg (IQR, 99.5-137.0). After a median follow-up of 1.3 years (IQR, 0.9-1.7), the median percent weight loss was 33.7% (IQR, 26.8-37.3). Two patients experienced post-operative complications following BS (Table 1). At the time of last available follow-up (median 6.9 years), the median percent weight loss was 24.4% (IQR, 16.7-37.2). Median daily SF pre-BS was 6 bowel movements (IQR, 6.0-9.5). Following BS, median daily SF at the time of initial follow-up (median 1.3 years) and last follow-up (median 6.9 years); was 8.5 (IQR, 6.5-14.0) and 6.0 (IQR, 4.5-7.0), respectively. Clinical mPDAI scores are highlighted in Table 2. There was no trend for increased risk of antibiotic use, acute or chronic pouchitis, advanced therapy requirements, emergency department visits, or IBD-related hospitalizations (Table 2).