One-anastomosis gastric bypass versus Roux-en-Y gastric bypass for recurrent weight gain after sleeve gastrectomy in patients with type 2 diabetes mellitus and hypertension: a single-center retrospective comparative cohort study

Recurrent weight gain (RWG) after laparoscopic sleeve gastrectomy (LSG) often requires conversion surgery. One-anastomosis gastric bypass (OAGB) and Roux-en-Y gastric bypass (RYGB) are commonly used conversion procedures, but comparative data in patients with type 2 diabetes mellitus (T2DM) and hypertension (HTN) are limited. This study compared outcomes of OAGB and RYGB in this population. Patients with RWG after LSG who underwent conversion to OAGB or RYGB between December 2022 and April 2024 at a single tertiary center in Istanbul, Türkiye, were retrospectively analyzed. All patients had T2DM and HTN and completed 2-year follow-up. Weight loss, body mass index (BMI), complete remission (CR) of T2DM and HTN, and postoperative complications were compared. Between-group analyses were unadjusted. Forty-five patients were included (OAGB, n = 21; RYGB, n = 24). OAGB achieved greater total weight loss at 1 year (31.0 ± 3.7% vs. 25.1 ± 7.2%, p = 0.001) and 2 years (37.8 ± 3.8% vs. 29.1 ± 8.8%, p < 0.001), with lower BMI at 2 years (26.9 [25.8–28.0] vs. 31.0 [27.7–33.2] kg/m 2 , p = 0.007). At 2 years, CR of T2DM (81.0% vs. 50.0%, p = 0.030) and HTN (90.5% vs. 50.0%, p = 0.003) were higher after OAGB. Three early postoperative complications occurred, all in the RYGB group, including two Clavien–Dindo grade II complications and one grade IIIb complication. In LSG patients with RWG, Conversion to OAGB was associated with greater weight loss and higher CR rates of T2DM and HTN compared with RYGB. Early postoperative complications were infrequent, and the study was not powered to compare safety outcomes. Larger prospective studies are required to confirm these findings.