Importance of pouch size in laparoscopic Roux-en-Y gastric bypass: a cohort study of 14,168 patients

Laparoscopic Roux-en-Y gastric bypass (LRYGB) is one of the most common bariatric procedures worldwide, but the importance of gastric pouch size is still under debate. We have studied how pouch size affects risk of marginal ulcer and excess body mass index loss (EBMIL%) at 6 weeks and 1 year postoperatively. Scandinavian Obesity Surgery Registry included 14,168 LRYGB patients with linear stapled gastrojejunostomies, having complete pre- and postoperative data concerning length of stapler needed to complete the gastric pouch, incidence of marginal ulcers and weight loss. LRYGB technique in Sweden is highly standardized, and total length of stapler was used as a proxy for pouch size. Mean length of stapler used for the pouch was 145 mm. At 1 year, symptomatic marginal ulcers were noted in 0.9 % of the patients. The relative risk of marginal ulcer increased by 14 % (95 % confidence interval 9-20 %), for each centimeter of stapler used for the pouch. Body mass index (BMI) was reduced from 42.4 +/- A 5.1 to 36.1 kg/m(2) at 6 weeks and 28.9 kg/m(2) at 1 year. The total length of stapler predicted EBMIL% at 6 weeks but not at 1 year. Female gender, low preoperative BMI, young age and absence of diabetes predicted better EBMIL% at 1 year. A smaller pouch reduces the risk of marginal ulcers, but does not predict better weight loss at 1 year. Additional stapling should be avoided as each extra centimeter increases the relative risk of marginal ulcers by 14 %.