The Efficacy of Conversional One Anastomoses Gastric Bypass post Sleeve Gastrectomy and Gastric Band: A Large Single Cohort Series

Abstract

Introduction Conversional bariatric procedures are increasing, particularly conversional one-anastomosis gastric bypasses (cOAGB). This study reports long-term and patient-reported outcomes for cOAGB after laparoscopic adjustable gastric banding (LAGB) and sleeve gastrectomy (SG). Methods This retrospective single-cohort review of a prospective database examined all cOAGB cases (2016-2023). Perioperative morbidity, long-term surgical or endoscopic interventions, and patient-reported outcomes were analysed. Results Within the largest published cohort of 261 consecutive cOAGB patients, 60.9% had prior-LAGB and 39.1% had prior-SG. Within 30 days, three severe and 13 low-grade complications occurred without mortality, with 98.9% of patients home the following day. Twenty-four longer-term surgical interventions were performed for reflux, port-site hernia, perforated ulcer or adhesions. 14 cases of anastomotic ulcer and one reflux oesophagitis were managed conservatively. 60.9% of patients responded to the survey (35.7 months post-cOAGB). 37.1% reported heartburn and 23.9% reported regurgitation. 81.8% of patients reported they were happy with the procedure, and 78% reported they would choose it again, both outcomes associated with greater percentage excess weight loss (%EWL) and lower heartburn scores. Higher satisfaction was associated with less regurgitation or prior-LAGB. Mean BMI (41.8 months after conversion) was 31.5kg/m² (9.7kg/m² less than before conversion), with mean %EWL of 64.6% (significantly higher in female patients) and mean TBWL of 22.5%. Conclusion cOAGB was found to be safe and effective for further weight loss or persistent reflux. Although these issues may not be fully resolved, the relative improvement is reflected in the strong satisfaction scores, supporting the use of this technique in conversional surgery.