Revisional one-anastomosis gastric bypass versus SADI-S following sleeve gastrectomy for recurrent obesity: a comparative study of metabolic, nutritional, and quality-of-life outcomes

Background Revisional bariatric surgery is increasingly performed due to inadequate weight loss, weight regain, or complications following primary bariatric procedures. One anastomotic gastric bypass (OAGB) and single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) are commonly used revisional options, yet comparative data on metabolic, nutritional, and quality-of-life outcomes remain limited. Objective To compare metabolic, nutritional, perioperative, and quality-of-life outcomes between revisional OAGB and SADI-S. Methods A retrospective comparative cohort study was conducted at a tertiary bariatric center between 2020 and 2025. Adult patients undergoing revisional OAGB or SADI-S after sleeve gastrectomy with recurrent obesity were included. Outcomes included weight loss, metabolic and nutritional parameters, perioperative outcomes, complications, and quality of life assessed using BAROS and SF-BARI questionnaires. A sensitivity analysis including only patients with weight regain was performed. Adjustment for baseline nutritional values was performed using ANCOVA. Results Forty-four patients were included (22 OAGB, 22 SADI-S). At one year, no statistically significant differences in weight loss were observed between groups (EWL 43% vs. 37%, p > 0.9; TWL 18% vs. 15%, p = 0.9). SADI-S demonstrated superior lipid profile improvement, including lower total cholesterol (119 vs. 153 mg/dL, p = 0.005) and LDL levels (65 vs. 85 mg/dL, p = 0.032). Vitamin B12 levels were higher after SADI-S (475 vs. 330 pg/mL, p = 0.015), while no statistically significant between-group differences were observed in the other nutritional parameters. Operative time was shorter for OAGB (90 vs. 109 min, p = 0.019). No statistically significant between-group differences were observed in quality-of life scores. Conclusion In this small retrospective cohort, no statistically significant differences were detected between revisional OAGB and SADI-S regarding short-term weight-loss or quality-of-life outcomes. SADI-S was associated with greater improvement in lipid profile, whereas OAGB demonstrated a trend toward a more favorable nutritional profile. However, the study was not powered to establish equivalence between procedures, and these findings should be considered exploratory and hypothesis-generating.