Single anastomosis duodenal switch versus Roux-en-Y gastric bypass in patients with BMI ≥ 50 kg/m2: a multi-centered comparative analysis

Background Roux-en-Y gastric bypass (RYGB) has consistently demonstrated excellent weight loss and comorbidity resolution. However, outcomes vary based on patient's BMI. Single anastomosis duodeno-ileostomy with sleeve (SADI-S) is a novel procedure with promising short-term results. The long-term outcomes of SADI-S in patients with BMI >= 50 kg/m(2) are not well described. We aim to compare the safety and efficacy of SADI-S with RYGB in this patient population. Methods We performed a multicenter retrospective study of patients with a BMI >= 50 kg/m(2) who underwent RYGB or SADI-S between 2008 and 2023. Patient demographics, peri- and post-operative characteristics were collected. Complication rates were reported at 6, 12, 24, and 60 months postoperatively. A multivariate linear regression was used to evaluate and compare weight loss outcomes between both procedures. Results A total of 968 patients (343 RYGB and 625 SADI-S; 68.3% female, age 42.9 +/- 12.1 years; BMI 57.3 +/- 6.7 kg/m(2)) with a mean follow-up of 3.6 +/- 3.6 years were included. Patients who underwent RYGB were older, more likely to be female, and have a higher rate of sleep apnea (p < 0.001), hypertension (p = 0.015), dyslipidemia (p < 0.001), and type 2 diabetes (p = 0.016) at baseline. The rate of bariatric surgery-specific complications was lower after SADI-S compared to RYGB. We reported no bariatric surgery related deaths after 1 year following both procedures. SADI-S demonstrated statistically higher and sustained weight loss at each time interval compared to RYGB (p < 0.001) even after controlling for multiple confounders. Lastly, the rate of surgical non-responders was lower in the SADI-S cohort. Conclusions In our cohort, SADI-S was associated with higher and sustained weight-loss results compared to RYGB. Comorbidity resolution was also higher after SADI-S. Both procedures demonstrate a similar safety profile. Further studies are required to validate the long-term safety of SADI-S compared to other bariatric procedures.