Single-anastomosis duodenoileal bypass versus one-anastomosis gastric bypass: 1-year results of the OASIS…

Randomized trialSurgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery· Jul 2026

Single-anastomosis duodenoileal bypass versus one-anastomosis gastric bypass: 1-year results of the OASIS randomized trial.

Sergi Sanchez-Cordero, Ruth Lopez-Gonzalez, Paula Garcia … Jordi Pujol-Gebelli

Read paper

Bariatric & Metabolic SurgeryRandomized trialTreatmentQ1IF 2.1

One-anastomosis gastric bypass had significantly more late complications than single-anastomosis duodenoileal bypass.

Single-anastomosis duodenoileal bypass versus one-anastomosis gastric bypass: 1-year results of the OASIS randomized trial.

Sergi Sanchez-Cordero … Jordi Pujol-Gebelli

Surgery for obesity and related diseases · Jul 2026 · Q1 in Surgery

Background

Single-anastomosis duodenoileal bypass with sleeve gastrectomy (SADI-S) and one-anastomosis gastric bypass (one-anastomosis gastric bypass) are increasingly used bariatric procedures, but high-quality comparative evidence remains limited.

Purpose

To compare 1-year efficacy and safety outcomes of SADI-S and one-anastomosis gastric bypass as primary bariatric procedures in patients with severe obesity.

Methods

Were randomly assigned (1:1) using a computer-generated sequence.

n = 90 underwent surgery (43 SADI-S; 47

Results

bile reflux and other late problems were far more common after one-anastomosis gastric bypass than SADI-S

OAGB

35.4%

SADI-S

7.1%

More results

At 1 year, no significant differences were observed between groups in excess weight loss (84.34% vs 79.61%; P = .209), total weight loss (35.85% vs 33.02%; P = .075), or BMI (27.93 vs 28.92 kg/m 2 ; P = .168).

Comorbidity resolution rates were comparable.

More results

Nutritional deficiencies were infrequent (7.3% vs 4.3%; P = .878), with all cases related to iron deficiency.

SADI-S was associated with fewer complications but included two cases requiring surgical reintervention.

“

Conclusion · 1 of 3

SADI-S and one-anastomosis gastric bypass achieved comparable weight loss and metabolic outcomes at 1 year in patients with BMI 45-50 kg/m 2 but showed distinct complication profiles.

Conclusion · 2 of 3

one-anastomosis gastric bypass was associated with a higher rate of bile reflux-related events, whereas SADI-S had fewer but more severe complications. These findings support an individualized approach to procedure selection.

Conclusion · 3 of 3

Longer-term follow-up is required.

Single-anastomosis duodenoileal bypass versus one-anastomosis gastric bypass: 1-year results of the OASIS randomized trial.

Single-anastomosis duodenoileal bypass versus one-anastomosis gastric bypass: 1-year results of the OASIS randomized trial.

Related papers