Botulinum A Toxin Injected into the Gastric Wall for the Treatment of Class III Obesity: A Pilot Study

Background: Obesity represents a major public health problem in western countries. Initial studies suggest that injection of botulinum A toxin (Btx-A) into the antropyloric region inhibits propulsive contractions of the antral pump, with delay in gastric emptying, early satiety and weight loss. Methods: After approval by the University Ethics Committee, we prospectively evaluated 12 patients with class III obesity divided into 4 groups of 3 patients each. In groups I and II, 200 U Btx-A were injected into the antropyloric region at 8 and 16 sites, respectively. Groups III and IV received 300 U Btx-A into the antropyloric region at 16 and 24 sites, respectively. Body weight and gastric emptying time (GET) of solids and semi-solids using ¹³C-octanoic acid breath test and ¹³C-acetic acid breath test, respectively, were determined before and after injection over a period of 12 weeks. Results: Pre- and post-treatment body weight or solid and semi-solid GET did not differ significantly between groups (P>0.05). All patients reported a feeling of early satiety. No adverse effects related to BtxA or complications resulting from the endoscopic procedure were observed. Conclusion: The injection of different doses of BtxA at different sites in the antropyloric region of patients with class III obesity did not interfere significantly with the solid and semi-solid GET or body weight of these individuals. However, early satiety was reported by all patients, the procedure was safe and no side-effects of the treatment were observed. Further controlled studies involving different methodologies regarding dosage of Btx-A and sites of injection are necessary.