Long-Term Outcomes of One Anastomosis Gastric Bypass: A Systematic Review and Meta-Analysis of 5-Year and Beyond

One-anastomosis gastric bypass (OAGB) has gained global prominence as the third most performed bariatric procedure. Despite evidence of short-term efficacy, long-term outcomes remain understudied. This PRISMA-compliant systematic review and meta-analysis evaluated long-term (≥ 5 years) outcomes of OAGB as primary and revisional procedures. Quality assessment and bias evaluation were conducted systematically. Analysis included 32 studies with 19,125 patients (76% primary OAGB) from 14 countries with mean follow-up of 6.7 years. At five years, mean excess weight loss(EWL) was 75%, increasing to 77% beyond five years. Obesity associated diseases resolution was substantial: type 2 diabetes (80%), obstructive sleep apnea (89%), and hypertension (61%). Complications were minimal: bile reflux (4%), marginal ulceration (2%), and malnutrition (1%). For revisional OAGB, %EWL at five years was 71%. The conversion rate to other bariatric procedures (all RYGB) was reported in 3% of patients following OAGB. This analysis demonstrates OAGB's effectiveness for sustained weight loss and obesity associated diseases improvement at ≥ 5 years, supporting its role in long-term obesity management as a primary and revisional bariatric intervention. [Abstract copyright: © 2025. The Author(s).]