SADI-S as a Conversion for Suboptimal Clinical Response and Recurrent Weight Gain Following Bariatric Surgery: A Retrospective Cohort Study

Background: Recurrent weight gain (RWG) and Suboptimal Clinical Response (SCR) after primary metabolic and bariatric surgery (MBS) are common, often necessitating revisional procedures. Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) has emerged as a promising conversion option. Methods: We retrospectively reviewed patients who underwent laparoscopic conversion to SADI-S for RWG/SCR between 2018 and 2024. Eligible patients had prior MBS after meeting national guidelines. Data included demographics, weight-loss outcomes, complications and nutritional/metabolic markers. The primary outcomes were percent of total weight loss (%TWL) and excess weight loss (%EWL). Long-term complications and need for revisional surgery were also assessed. Results: Sixty-nine patients (mean age 42.7 ± 9.8 years; 66.7% female) were included. Most (65.2%) were converted from sleeve gastrectomy. Mean follow-up was 2.2 ± 1.4 years. Mean %TWL was 36.4%, 37.8%, and 34.5% at 1, 3, and 5 years, respectively, and %EWL exceeded 90% at all time points. Major complications (Clavien-Dindo ≥ 3b) occurred in 5.8% within 90 days, with 4 reoperations in the perioperative period. No conversional surgeries were required during the follow-up period. Conclusions: Conversion to SADI-S is a safe and effective option for RWG/SCR following primary MBS, yielding durable weight loss and metabolic improvement with low complication rates. These findings support its use as a conversion strategy, warranting further prospective validation.