Short-term Safety of one Anastomosis Gastric Bypass (OAGB) Versus Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy (SADI-S): 30-day Results from the OASIS trial.

Abstract

BACKGROUND: Metabolic and bariatric surgery (MBS) is an effective treatment for obesity, but selecting the optimal technique remains challenging. One Anastomosis Gastric Bypass (OAGB) and Single Anastomosis Duodeno-Ileal with Sleeve Gastrectomy (SADI-S) are increasingly used, yet direct comparisons are scarce. OBJECTIVES: To compare 30-day outcomes of OAGB and SADI-S in patients with a BMI of 45–50 kg/m², focusing on safety and short-term efficacy within the OASIS trial. METHODS: In this randomized, single-blind trial, 89 patients underwent laparoscopic OAGB (n = 48) or SADI-S (n = 41). The primary endpoint is 5-year weight loss; this manuscript reports a planned 30-day safety analysis. Complications were graded using the Clavien-Dindo scale. Secondary outcomes included operative time, hospital stay, and early weight loss. RESULTS: Severe complications (Clavien-Dindo ≥ IIIb) occurred in 7.3% of SADI-S and 2.1% of OAGB patients (p = 0.33). Reoperations were also more common in SADI-S (7.3% vs. 2.1%; p = 0.33). Operative time was significantly longer for SADI-S (103.8 ± 18.4 vs. 82.2 ± 23.9 min; p < 0.001). No significant differences were found in early weight loss or comorbidity resolution. No 30-day mortality was recorded. CONCLUSIONS: OAGB was associated with fewer complications and shorter operative times compared to SADI-S, although differences in severe complications and reoperations were not statistically significant. Long-term data are needed to fully evaluate outcomes.