Primary and Revisional One Anastomosis Gastric Bypass: A Systematic Review and GRADE-Based IFSO Position Statement

Obesity is a chronic, systemic disease that alters the function of tissues, organs, and overall health, requiring prompt recognition and treatment by qualified professionals. IFSO recognizes the need to provide a new methodology for developing IFSO position statements. All new official position statements should be developed using a GRADE-based methodology, systematically reviewing all available evidence relevant to Metabolic and Bariatric Surgery (MBS). The present Position Statement was developed using results coming from a systematic review and meta-analysis, reported herein, following the criteria of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Fourteen Randomized controlled trials (RCTs) were included in this meta-analysis, 13 and 1 of them assessing outcomes of OAGB in primary and revisional setting respectively, with a total of 1288 patients. In the short term, OAGB exhibited a significantly higher excess weight loss percentage (EWL%) compared to RYGB. Regarding weight loss and metabolic outcomes, OAGB was not reported to be inferior in terms of weight loss and T2DM resolution when compared to RYGB. Further RCTs comparing OAGB to other MBS procedures are needed to reach a definitive recommendation regarding OAGB in revisional surgery setting. Regarding safety profile, no statistically significant differences between OAGB and other MBS were reported. This position statement was issued by the IFSO OAGB task force and approved by IFSO Scientific Committee aims to provide evidence on the effectiveness of One Anastomosis Gastric Bypass in both primary and revisional settings.