Supplementary Material for: The Efficacy and Safety of Adjustable Intragastric Balloon for Weight Loss: a Systematic Review and Meta-Analysis

Introduction: Adjustable intragastric balloon (aIGB), as known as a novel minimally invasive therapy for obesity, provide a sustained alternative for weight loss. Weight loss is achieved by implanting a balloon into the patient's stomach, with the volume of the balloon being adjustable through the injection or extraction of physiological saline. Its key distinction from other intragastric balloons lies in post-implantation volume control. Currently, the efficacy and safety of aIGB have not been well described. Methods: MEDLINE, Embase, and Cochrane Library were searched for relevant articles. Efficacy and safety of aIGB were evaluated by total body weight loss (TWL) after treatment and severe adverse events. Results: A total of 12 eligible studies with 4981 patients were included. The average inserting time was 9.9 months, and the pooled mean TWL was 16.4% (95%CI 0.153 - 0.175, I2 = 91.2%). The pooled prevalence of patients choosing upward balloon adjustment was 34.2% (95%CI 0.220 - 0.485, I2 = 96.5), and all reported additional weight loss with a mean of 6.3 (4.8~9.3) kg. The pooled prevalence of patients choosing downward balloon adjustment was 9.2% (95%CI 0.065 - 0.119, I2 = 73.9%), and the pooled prevalence of alleviating intolerance in these patients was 90.8% (95%CI 0.817-0.974, I2 = 53.4%). The pooled prevalence of intolerance and early removal within 3 months was 5.7% (95%CI 0.035 - 0.078, I2 = 79.8%), and the pooled prevalence of stomach ulcer was 1.1% (95%CI 0.008 - 0.014, I2 = 5.1%). There was no obvious publication bias detected for these outcomes. Leave-one-out and subgroup analysis demonstrated the results were statistically reliable. Conclusion: aIGB has the ability of significant and sustained weight loss, and can effectively manage both intolerance and weight loss plateaus by adjusting the balloon volume during treatment.