Five-year outcomes of two duodenal switch variants: BPD/DS vs. SADI-S

Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is a modification of biliopancreatic diversion with duodenal switch (BPD/DS) intended to simplify reconstruction while preserving efficacy. Comparative mid-term outcome data remain limited. We compared 5-year outcomes of SADI-S versus BPD/DS at two high-volume bariatric centers.

We retrospectively reviewed primary SADI-S and BPD/DS performed from 1/1/2008 to 5/31/2020 to allow for 5 years of follow-up. Demographics, operative characteristics, weight loss, comorbidity resolution, and complications were assessed. Nonparametric tests were used for continuous variables and chi-square/Fisher's exact tests for categorical variables.

516 patients underwent SADI-S (158) and BPD/DS (358). Baseline demographics and comorbidities were comparable (p > 0.05). Operative time was shorter for SADI-S (median 150 [131.5-179] vs. 174 [152-199] min; p < 0.001). All following values are reported as SADI-S vs. BPD/DS: % Total weight loss peaked at 2 years (42.13 vs. 40.42%; p = 0.536) and remained similar at 5 years (37.14 vs. 35.61%; p = 0.434). A small difference at 6 months favored BPD/DS (22.98 vs. 24.96%; p = 0.002). Follow-up rates at 2 and 5 years were 69.0 vs 78.2% and 44.3 vs. 55.9%; median overall follow-up was 6.67 vs. 6.22 years (p = 0.502). At 5 years, resolution rates of diabetes (76.7 vs. 79.7%, p = 0.729) and hypertension (51.5 vs. 49.7%, p = 0.802) were comparable with similar findings in hyperlipidemia and obstructive sleep apnea. While overall rates of early and late complications were similar, more early reoperations were seen after SADI-S (6.3 vs. 2%, p = 0.010), and more nutritional deficiencies were seen with BPD/DS (8.9 vs. 17.6%, p = 0.010). Revisional surgery rates were similar (5.1 vs. 3.1%, p = 0.268).

At 5 years, SADI-S and BPD/DS achieved comparable weight loss, metabolic outcomes, and complication rates. SADI-S offered shorter operative duration while maintaining mid-term efficacy, supporting its role as an effective alternative to BPD/DS while avoiding nutritional deficiencies.