Influence of pouch and stoma size on weight loss after gastric bypass

Enlargement of the gastric pouch and/or gastrojejunostomy after Roux-en-Y gastric bypass (RYGB) is postulated to be the antecedent to suboptimal weight loss or weight regain. The present study evaluated the gastric pouch and stoma dimensions in RYGB patients and correlated them with the weight loss outcomes.

Patients who underwent upper endoscopy for investigation of gastrointestinal symptoms or weight regain after RYGB were identified. The stoma was considered enlarged if >2 cm in diameter and the pouch was considered enlarged if >6 cm long or >5 cm wide. Successful weight loss was defined as excess weight loss >50% or a body mass index decrease to ≤ 30 kg/m(2).

A total of 380 patients had nondiagnostic upper endoscopy findings at a mean post-RYGB interval of 5.9 ± 4.0 years. Among these were 175 patients (group A; 87% women) who had successful weight loss and 205 patients (group B; 86% women) who were referred for investigation of weight regain. The pouch and stoma size were normal in most of the patients in group A (63.4%) compared with 28.8% of the patients in group B (P <.001). The most common abnormality was an enlarged stoma. The pouch length, pouch volume, and stoma diameter correlated inversely with excess weight loss. Multivariate analysis identified that the stoma diameter was independently associated with weight regain after RYGB.

The current definition of a "normal" size pouch/stoma is associated with optimal weight loss after RYGB, although this might need to be reviewed. Patients who regain weight are likely to have abnormal anatomy, in particular, stoma enlargement. The surgical RYGB technique and methods of evaluating the gastric anatomy in RYGB patients need to be standardized, intraoperatively and postoperatively.