Efficacy and safety of the gastric bypass stent system in Chinese adults with obesity: A multicenter, randomized controlled trial

To the Editor: Obesity is a widespread chronic disease with a simultaneous increase globally. Endoscopic bariatric methods include intragastric balloons, endoscopic sleeve gastroplasty, and duodenal-jejunal bypass liner (DJBL). DJBL contains a stent anchored at the duodenal bulb and an endoscopically delivered 60-cm impermeable sleeve that covers the surface of the duodenum and the proximal jejunum. The most common DJBL is EndoBarrier (GI Dynamics, Inc., Watertown, Massachusetts), but adverse effects, especially hepatic abscess, limit its use.[1] In this study, we used a novel endoscopic DJBL-gastric bypass stent system (GBSS; Hangzhou Tangee Medical Technology Co., Ltd., China) for weight control. Compared with EndoBarrier, GBSS [Supplementary Figure 1, https://links.lww.com/CM9/C841] has made several technical innovations, particularly the use of antibacterial polymer composite materials for sleeves, which might help reduce the occurrence of hepatic abscess. This was a multicenter, randomized, parallel controlled, open-label trial that enrolled patients from seven medical centers in China [Supplementary File 1, https://links.lww.com/CM9/C902]. The study was conducted in accordance with the principles of the Declaration of Helsinki. The trial was approved by the ethics committe of Beijing Friendship Hospital (No. 2019-P1-028-02). All patients signed informed consents. The study was registered at www.clinicaltrials.gov (NCT05938231). Eligible individuals were adults aged 18–60 years with a body mass index (BMI) of ≥30 kg/m2. The key exclusion criteria were as follows: weight loss of >4.5 kg in the past 3 months; use of bariatric medication; severe organ dysfunction of the heart, lung, liver, or kidney; type 1 diabetes mellitus; anticoagulant or antiplatelet drug use; severe coagulopathy; iron deficiency; history of peptic ulcer, gastrointestinal bleeding, ileus, pancreatitis, or hepatic abscess; cholecystitis; symptomatic gallstones; gallstones larger than 20 mm in diameter; and pregnancy/intent to become pregnant. The study lasted for 9 months. After screening, all patients underwent gastroscopy and were randomly assigned at a 1:1 ratio to the GBSS group (GBSS with dietary control for the first 3 months and then dietary control for another 6 months) or the control group (only dietary control for 9 months). GBSS was both implanted and removed endoscopically under general anesthesia. Neither the research staff nor the participants were blinded to the intervention after randomization. All the participants received a liquid/semiliquid diet for the first week after gastroscopy, followed by a daily caloric intake of less than 25 kcal/ideal body weight (weight [kg] at which BMI = 25 kg/m2). All the subjects were scheduled for follow-up at months 1, 3, 4, 6, and 9, and those in the GBSS group had an extra follow-up within 7 days of implantation to monitor adverse events (AEs). Data collection included demographic information, medical history, symptoms of discomfort, laboratory results (complete blood count, liver function, blood glucose, fasting insulin, blood amylase, blood iron tests, and fecal occult blood), electrocardiography, and abdominal ultrasonography. The primary outcome was the percentage of excess weight loss (EWL%) at month 3. EWL% = (Baseline weight – Weight at follow-up)/(Baseline weight – Weight at a BMI of 25 kg/m2) × 100%. The secondary outcomes included EWL% at months 1, 4, 6, and 9; the percentage of total weight loss (TWL%); changes in body weight, BMI, and insulin resistance at each visit; and device safety. Insulin resistance was assessed by the homeostasis model assessment of insulin resistance (HOMA-IR). HOMA-IR was calculated as fasting blood glucose (mmol/L) × fasting insulin (μU/mL)/22.5, and a value ≥2.69 was considered insulin resistance. Statistical analyses were performed with SAS version 9.4 (SAS Institute Inc, Cary, NC). A superiority test was used for the primary outcome, with a significance level of α = 0.025 (one-sided) and a confidence level of 1 – β = 0.8. For the other tests, the significance level was α = 0.05 (two-sided), and the confidence level was 1 – β = 0.8. A P value of