Ten-year comparative outcomes of one-anastomosis gastric bypass versus single-anastomosis duodeno-ileal bypass as revisional procedures after sleeve gastrectomy

Abstract Background A substantial proportion of patients have insufficient weight loss or clinically significant weight regain after sleeve gastrectomy (SG) and require revisional surgery. One-anastomosis gastric bypass (OAGB) and single-anastomosis duodeno-ileal bypass (SADI-S) are commonly used conversion procedures, but long-term comparative data are limited. Objectives To compare 10-year weight, metabolic, nutritional and safety outcomes of OAGB versus SADI-S performed as conversion procedures for weight recurrence after SG. Setting Tertiary referral bariatric center. Methods In this retrospective comparative cohort study, adults undergoing conversion of SG to OAGB or SADI-S for weight recurrence between January 2014 and January 2016 were identified. Demographic, anthropometric, metabolic and micronutrient data, comorbidity status and complications were collected at baseline (time of conversion) and at 1, 5 and 10 years. Analyses were primarily descriptive. Between-group comparisons used appropriate parametric/non-parametric tests for continuous variables and Fisher’s exact/chi-square tests for categorical variables; no multivariable longitudinal adjustment was performed, and findings should therefore be interpreted cautiously in view of the retrospective, non-randomized design. Results Ninety patients underwent revisional surgery (OAGB n = 47; SADI-S n = 43). At 1 year, weight outcomes were similar between groups. SADI-S achieved higher %EWL and %TWL at 5 years; however, 10-year weight and BMI outcomes were comparable. Lipid profiles were more favorable after SADI-S (lower total cholesterol at 1, 5 and 10 years; lower triglycerides at 5 and 10 years), whereas several micronutrient levels were higher after OAGB (including calcium, zinc, vitamin D and folate at multiple time points), with higher vitamin B12 after SADI-S. Comorbidity outcomes and overall complication rates were similar, and no mortality was observed during follow-up. Conclusions In this retrospective cohort with 10-year follow-up, OAGB and SADI-S were associated with comparable long-term weight outcomes when used as conversion procedures after SG. SADI-S was associated with more favorable lipid parameters, whereas OAGB showed higher levels of several micronutrients over follow-up. These findings should be interpreted as observational associations and may help inform, rather than determine, individualized procedure selection alongside structured long-term surveillance.