IBC Oxford University Oral Abstract 37 - One anastomosis gastric bypass <i>versus</i> Roux-en-Y gastric bypass for obesity: an updated meta-analysis and systematic review of randomized controlled trials

Abstract Introduction Roux-en-Y gastric bypass (RYGB) is currently regarded as the predominant method for bariatric surgery. However, one anastomosis gastric bypass (OAGB) emerged after RYGB as a more straightforward and readily reversible operation. In this systematic review and meta-analysis, our aim is to compare both procedures and update the currently existing evidence. Methods We systematically searched PubMed, Scopus, and the Cochrane Central Register systematically searched for randomized controlled trials (RCTs) that compared OAGB with RYGB as primary operations in terms of weight loss, comorbidities resolution, and post-operative complications in bariatric patients. Revisional surgeries were excluded from the analysis. Results Twelve studies were included in this meta-analysis, with a total of 904 patients. 445 patients were assigned to OAGB group (0.49%). The follow-up periods ranged from 6 months to 60 months. Total weight loss percentage (TWL%) was statistically higher in OAGB group at 6 months (95% c.i.:0.80 to 2.94; P = 0.006) with no differences at 12, 24, 36 months when compared to RYGB. On the other hand, OAGB exhibited a significantly higher excess weight loss percentage (EWL%) in comparison to RYGB at 12 months (95% c.i.: 3.08 to 9.73; P = 0.0002). EWL% was comparable in both procedures at 6, 24, 60 months of follow-up, which suggests that OAGB yields similar weight loss outcomes when compared to RYGB. There were no statistically significant differences in terms of resolution of diabetes mellitus, hypertension, dyslipidemia, obstructive sleep apnea and musculoskeletal pain. De Novo gastro-esophageal reflux disease (GERD) (RR 2.58; 95% c.i. 1.55 to 4.3; P = 0.0003) and marginal ulcers (RR 2.7; c.i. 95% 1.07 to 6.84; P = 0.04) were significantly higher in patients who underwent OAGB in comparison to RYGB. In contrast, diarrhea and dumping syndrome had a similar incidence in both procedures. Conclusion In conclusion, OAGB is not inferior to RYGB in terms of weight loss parameters and comorbidities resolution. However, OAGB can lead to a higher risk of development of marginal ulcers and de Novo GERD.