Endoscopic Botulinum Therapy for Obesity: Focus on the Antrum and Fundus.

[INTRODUCTION] Gastric botulinum toxin therapy is gaining attention as a non-invasive treatment for obesity. However, existing studies show inconsistent results and standardized protocols remain lacking. We aimed to evaluate the efficacy and safety of a novel whole-stomach injection method emphasizing the antrum and fundus in obese patients in Japan.

[METHODS] A total of 144 obese patients (mean age 42.3 years, mean BMI 30.3 kg/m²) underwent gastric botulinum toxin therapy at our institution between February 2023 and November 2024. Coretox (300-400 U) was injected endoscopically across the entire stomach, with increased concentration in the antrum and fundus. Patients were followed for six months post procedure. The primary outcome was the percentage of total body weight loss (%TBWL), and safety was assessed by the occurrence of complications per Clavien-Dindo classification.

[RESULTS] Mean %TBWL was 6.5% at one month, 10.2% at three months, and 12.2% at six months post treatment. No complications or adverse events were reported. The average procedure time was 5.7 minutes, and all patients completed follow-up as scheduled. We hypothesize that the observed efficacy may be partially attributed to our refined injection technique and individualized BMI-based dosage adjustment, although further controlled studies are needed to validate this approach.

[CONCLUSION] Gastric botulinum therapy using a novel full-stomach injection method focusing on the antrum and fundus was found to be both safe and effective in a Japanese obese population. This technique may offer a promising, minimally invasive option for obesity management. Further multicenter and long-term studies are warranted to validate and standardize this approach.