Visceral obesity as a predictor of ileal pouch reachability in ulcerative colitis: A prospective single-center study.

Aim: Obesity has been reported to increase the risk of technical inability in performing ileal pouch-anal anastomosis (IPAA) in patients with ulcerative colitis (UC). This study aimed to prospectively investigate the association between visceral fat and the feasibility of pouch reach in hand-sewn IPAA.

Methods: We prospectively enrolled patients with UC scheduled for two-stage restorative proctocolectomy with a preoperative plan for hand-sewn IPAA. Patients were categorized into a conversion group that required conversion to stapled IPAA intraoperatively and a non-conversion group. Preoperative visceral fat area and anatomical indicators were measured using computed tomography (CT). Logistic regression analysis was performed to identify predictors of conversion surgery.

Results: A total of 106 patients were included, with 12 (11.3%) in the conversion group. Compared with those in the non-conversion group, patients in the conversion group had significantly higher body mass index (BMI), greater visceral fat, and a longer distance between the ileal end and the anal verge (p < 0.01). Logistic regression identified visceral fat (per 10 cm² increase: odds ratio [OR] 1.19, 95% confidence interval [CI] 1.02-1.39, p = 0.01) as a significant predictor of conversion surgery, whereas BMI was not (OR 1.03, 95% CI 0.77-1.21, p = 0.72).

Conclusions: Visceral fat is an independent risk factor for conversion surgery in patients undergoing hand-sewn IPAA. Preoperative CT-based measurement of visceral fat may provide a more accurate prediction of pouch reachability than BMI alone. These findings may help surgeons decide preoperatively whether a hand-sewn IPAA is feasible.