Efficacy and Safety of a Novel Reversible Gastric Bypass Stent System for Weight Loss: A Multicentre Real-World Study.

OBJECTIVE: To evaluate the clinical efficacy and safety of the Gastric Bypass Stent System (GBSS), a novel reversible duodenal-jejunal bypass liner, in a large-scale real-world setting. METHODS: This retrospective multicentre real-world study included 1536 patients with overweight or obesity who underwent GBSS implantation across 239 hospitals in China. Participants were followed up monthly. The present analysis used registry data available up to a cutoff date of October 31, 2025. Primary efficacy endpoints included percentage total body weight loss (%TBWL), percentage excess weight loss (%EWL) and weight loss responder rates (proportion achieving > 5% and > 10% loss). Secondary endpoints focused on safety and adverse events (AEs). RESULTS: A total of 1536 participants with a mean BMI of 34.4 kg/m2 were included. Rapid weight loss was achieved by 3 months post-implantation, with mean %TBWL of 11.5% (SD 5.5) and mean %EWL of 50.1% (SD 30.4). Notably, 90.2% and 60.7% of participants achieved > 5% and > 10% weight loss, respectively. Weight loss remained relatively stable during 4-12 months after implantation, as supported by a mixed-effects model for repeated measures (MMRM) analysis. Regarding safety, stent displacement occurred in 4.6% of cases. Gastrointestinal bleeding was reported in 4.3% of participants, including haematemesis in 2.8% and melaena in 1.5%. The median implantation duration was 3 months, with intolerance being the most frequently reported reason for device retrieval. All reported AEs were managed conservatively or endoscopically, with no deaths or surgical interventions reported. CONCLUSIONS: The GBSS was associated with clinically meaningful weight loss as a minimally invasive intervention. Its safety profile is generally controllable; although stent displacement and intolerance occur, they are manageable. The GBSS may represent a promising reversible therapeutic option bridging the gap between conservative management and bariatric surgery.