Feasibility of gastric electrical stimulation by use of endoscopically placed electrodes

Background: Gastric electrical stimulation (GES), which has been reported to have therapeutic potentials for gastroparesis and obesity, involves the surgical placement of electrodes with the patient under general anesthesia. New methods are needed for implanting GES electrodes in a safer and more feasible way. Objective: Our purpose was to investigate the safety and feasibility of placing electrodes endoscopically for GES. Design and Setting: A pilot study. Subjects: Six female hound dogs that weighed 13 to 22 kg. Interventions: Endoscopically placed electrodes passed through the abdomen and the stomach wall. Main Outcome Measurements: The study was performed in dogs surgically implanted with gastric serosal electrodes and endoscopically implanted electrodes. The experiment consisted of a 30-minute baseline, a 30-minute GES, and a 30-minute recovery. GES was performed through endoscopically placed electrodes. Gastric slow waves were simultaneously recorded with the serosal electrodes and the endoscopically placed electrodes. Results: (1) The slow wave frequency recorded from the endoscopically placed electrodes was significantly correlated with that from the serosal electrodes (r = 0.97, P < .002). (2) GES through the endoscopically placed electrodes was able to entrain gastric slow waves. (3) No gastric leakage into the abdominal cavity was noted and the dogs were healthy and comfortable. (4) The endoscopically placed electrodes remained for 2 to 3 weeks. Limitations: The fixation of the electrodes needs to be improved for longer-term uses. Conclusions: GES may be accomplished without surgery by inserting the electrode wire through the abdomen under endoscopy. The study results indicate that the endoscopically placed electrodes are effective for GES and do not result in any adverse events.