One Anastomosis Gastric Bypass Versus Roux-en-Y Gastric Bypass for Obesity: a Systematic Review and Meta-Analysis of Randomized Clinical Trials

Introduction We aim to compare the efficacy and safety outcomes of one anastomosis gastric bypass (OAGB) with Roux-en-Y gastric bypass (RYGB). Methods We searched Ovid Medline, Ovid Embase, and the Cochrane Library from inception to May 14, 2019, without language restrictions, for randomized clinical trials comparing OAGB with RYGB in obesity. Quality of included trials was assessed by Cochrane Collaboration’s tool; quality of evidence was evaluated by GRADE approach. The primary outcome was excess body mass index (BMI) loss at 2 years. Results We identified 206 reports; after exclusions, three trials with a total of 733 patients were eligible for analysis. Compared with RYGB, OAGB was associated with more excess BMI loss at 2 years (mean difference (MD), 10.22; 95% CI, 3.05 to17.40; I 2 = 95%; low-quality evidence), with benefit seen in OAGB using non-obese patients (MD, 17.10; 95% CI, 15.76 to18.44; P for interaction = 0.007 ) and no benefit in OAGB using standard length of biliopancreatic limb (MD, 6.49; 95% CI, − 1.09 to 14.08). Moreover, individuals allocated to OAGB compared with RYGB had a higher remission rate of type 2 diabetes(T2D) (risk ratio (RR), 1.13; 95% CI, 1.01 to 1.27; I 2 = 0%). No statistically significant difference was found between the two surgical groups in adverse events. Conclusion OAGB is possibly associated with more body weight loss compared with RYGB in patients with obesity, despite the low quality of evidence caused by inconsistent of the effect of biliopancreatic limb length in OAGB group. This benefit appears to be confined to OAGB using the extended length of the biliopancreatic limb but not to OAGB using the standard length of the biliopancreatic limb, compared with RYBG. Additional large clinical studies are needed to assess the impact of limb length in OAGB.