Optimizing Roux-en-Y gastric bypass: results of the BPG-1 randomized trial on limb length configuration

The optimal limb lengths for Roux-en-Y gastric bypass (RYGB) to maximize weight loss and address obesity-related diseases remain debated.

To compare the effect of a longer versus shorter biliopancreatic limb (BPL) in RYGB on weight loss and remission of associated diseases.

Multicenter randomized controlled trial in three university hospitals in Spain.

Ninety-eight adults with a body mass index (BMI) of 35-50 kg/m² were randomized to receive either a 150 cm BPL with a 70 cm alimentary limb or the reverse configuration. Primary endpoint was weight loss at 2 years. Secondary endpoints included remission of obesity-related diseases, postoperative morbidity, and nutrients' status.

Mean age and BMI were 47 years (standard deviation [SD] 9) and 45 kg/m² (SD 4), respectively. Baseline demographic and clinical characteristics were comparable between groups. Mean operative time was 136 min (SD 30). Minimum median follow-up was 2 years. At 24 months, excess weight loss was 89% versus 78% (P = .02) and total weight loss was 39% versus 33% (P = .0002), favoring the long BPL group. Complete remission of type 2 diabetes mellitus (T2D) at 12 months was higher with the long BPL group (90% vs. 64%, P = .045). This finding was time-limited, with no significant difference at 24 months. No other comorbidities reached statistical significance.

A longer BPL in RYGB is associated with greater weight loss and higher T2D remission at 1 year, with favorable trends for other associated diseases, supporting individualized limb-length tailoring. Definitive conclusions regarding metabolic outcomes cannot be drawn without larger, adequately powered studies.