Seven-Year Comparative Outcomes of One Anastomosis Gastric Bypass and Roux-en-Y Gastric Bypass for Weight Recurrence Regain Post Sleeve Gastrectomy

BACKGROUND: Sleeve gastrectomy (SG) is currently the most performed bariatric procedure worldwide; however, up to half of patients may require conversion surgery due to insufficient weight loss, weight recurrence, or complications. Roux-en-Y gastric bypass (RYGB) and one-anastomosis gastric bypass (OAGB) are the two most common conversion options, yet evidence regarding long-term comparative outcomes remains limited. OBJECTIVE: This study compared the long-term outcomes of RYGB and OAGB after SG, focusing on weight loss, resolution of comorbidities, complication rates, and nutritional deficiencies. METHODS: We conducted a retrospective analytic study of all patients who underwent conversion RYGB or OAGB at our institution between January 2014 and December 2016. Data were extracted from electronic medical records, including demographics, comorbidities, perioperative details, and anthropometric and biochemical measures at baseline, 1, 5, and 7 years. Statistical analysis was performed using SPSS version 26. RESULTS: 109 patients were included (47 OAGB, 62 RYGB). Operative time was significantly shorter for OAGB. Both procedures achieved durable weight loss; however, OAGB yielded superior long-term outcomes, with greater %TWL and BMI reduction at one and seven years (p < 0.05). RYGB was significantly more effective for GERD resolution (p = 0.002). Rates of diabetes, hypertension, and dyslipidaemia remission were comparable. Complication rates were low and similar, though nutritional deficiencies, particularly iron deficiency, were more common in OAGB. CONCLUSION: OAGB provided superior long-term weight loss, while RYGB offered better GERD resolution. Both procedures were safe and effective, underscoring the need for individualised procedure selection. KEY POINTS: Both OAGB and RYGB demonstrated sustainable weight loss at 7-year follow-up after conversion from SG OAGB resulted in greater long-term weight loss, whereas RYGB provided better control of GERD symptoms. No significant differences were observed in terms of comorbidities control.