Gastric pouch volume is a major determinant of long-term Roux-en-Y Gastric Bypass (RYGB) failure

Background : The relationship between gastric pouch (GP) volume and long-term weight loss after Roux-en-Y gastric bypass (RYGB) remains poorly defined in the literature. Objectives : This study aimed to investigate the association between GP volume and weight loss failure in the long term following RYGB. Setting : University Hospital, France. A single-center cohort of patients with obesity undergoing RYGB surgery, with prospective data inclusion and retrospective analysis at a tertiary referral center. Methods : Forty-two patients who underwent RYGB between January 2020 and January 2024 were included. Patients presented with either insufficient weight loss or regain (RYGB failure) or abdominal symptoms requiring abdominal CT scan (control group). GP volume and gastrojejunal anastomosis (GJA) size were measured using a standardized low-dose CT scan protocol with contrast agent ingestion, analyzed by trained radiologists. Results : Of the 42 patients analyzed, 20 (47.6%) had weight loss failure, and 22 (52.4%) presented with recurrent abdominal pain. At a mean follow-up of 91.7 ± 31.8 months post-RYGB, 19 patients (45.2%) had a large GP, and 19 (45.2%) had an enlarged GJA. Ten patients (23.8%) had both an enlarged GJA and a large GP. While GJA size was not significantly associated with RYGB failure (p = 0.9), a large GP was strongly correlated with weight loss failure (p = 0.008). Conclusions : A large GP is significantly associated with RYGB failure, underscoring the importance of surgical technique in achieving long-term weight loss. These findings highlight the need for precise GP creation during RYGB to optimize outcomes.