Comparing the Efficacy and Safety of Roux-en-Y Gastric Bypass with One-Anastomosis Gastric Bypass with a Biliopancreatic Limb of 200 or 160 cm: 1-Year Results of the Tehran Obesity Treatment Study (TOTS).

PURPOSE: One-anastomosis gastric bypass (OAGB) has raised concerns about nutritional complications possibly attributed to the biliopancreatic limb (BPL) length. We aimed to assess the results of a conservative approach of OAGB compared with the original OAGB and Roux-en-Y gastric bypass (RYGB) in a 1-year follow-up study.

MATERIALS AND METHODS: This retrospective study was conducted based on prospectively maintained data in a cohort of patients who underwent either RYGB with a Roux limb of a 150 cm and a BPL of 50 cm (n = 145), OAGB with a 200-cm BPL (n = 272), or OAGB with a 160-cm BPL (n = 383), from March 2013 to 2017 at three university hospitals by a single surgical team.

RESULTS: Groups were comparable regarding age and sex. Mean preoperative body mass indexes of the RYGB, OAGB-160, and OAGB-200 groups were 44.5 ± 5.8, 45.6 ± 6.3, and 46.7 ± 6.4 kg/m2 , respectively. One-year follow-up rates were 83.4%, 85.3%, and 82.5% for the RYGB, OAGB-200, and OAGB-160 groups, respectively. One-year percent total weight loss values were 33.8 ± 6.7 after OAGB-160 and 35.3 ± 6.9 after OAGB-200 (P = 0.056), which were significantly greater compared with 30.9 ± 8.9 after RYGB (P < 0.001). All groups were comparable regarding remission of type 2 diabetes mellitus, hypertension, dyslipidemia, and fatty liver. Mean operative time was longer with RYGB than with either OAGB techniques. Groups were comparable for postoperative complications except for the incidence of protein-calorie malnutrition (PCM), occurring in 11 patients (4.7%) after OAGB-200, 7 of whom required revisional surgery, in one patient (0.3%) after OAGB-160 who responded to parenteral alimentation, but in no patients after RYGB.

CONCLUSION: After 1 year, OAGB with a 160-cm BPL was as effective as OAGB with a 200-cm BPL and RYGB, but safer than OAGB-200. This approach also avoided the need for revisional surgery following postoperative malnutrition.