Insufficient weight loss after banded vs. non-banded primary gastric bypass surgery: insights from an observational 5 year follow-up study.

Background: While Roux-en-Y gastric bypass (RYGB) is effective in achieving weight loss and improving obesity-related co-morbidities, insufficient weight loss in the long-term can occur. The goal was to assess whether banded vs. non-banded RYGB reduces the risk of insufficient weight loss at 5-year follow-up.

Methods: This is a retrospective single-center cohort study from Switzerland. We assessed the 5-year metabolic trajectories in terms of body weight, body mass index, glucose control, lipid profile and blood pressure of two surgical cohorts undergoing identical RYGB procedures with or without banding using a uniform 6.5 cm silastic Fobi band. Insufficient weight loss was defined as < 50% excess weight loss (EWL) at 5 years.

Results: A total of 55 patients receiving banded (Fobi) and 55 patients receiving non-banded (non-Fobi) RYGB were included in the analysis. 5-year follow-up was 91% for both groups. Percentage of EWL at 5 years was 78.11 ± 26.1% and 73.5 ± 27%.3 for the Fobi vs. non-Fobi group (p = 0.368), respectively. Insufficient weight loss (defined as < 50%EWL) at 5 years or last follow-up was significantly higher in the non-Fobi group compared to the Fobi group (19/55 vs. 9/55, respectively, OR = 2.639 (95% CI 1.066, 6.531), p = 0.036). Surrogate markers for cardiometabolic outcomes consistently improved over time, without differences between the groups. During the follow-up period, Fobi-removal was necessary in nine patients (16.3%).

Conclusion: Banded-RYGB lowered the odds of insufficient weight loss at 5 years follow-up by approximately 62%. Further research is needed to explore the effect of restriction on eating behaviour and neuroendocrine responses after RYGB.