Introduction Vagal dysfunction has been implicated in gastroparesis. Gut vagal afferents convey symptoms of nausea, bloating and early satiety but the nerve also has an antinociceptive function. GammaCore (electroCore, LLC: New Jersey) is a CE marked hand-held vagus nerve stimulator designed to selectively stimulate afferent vagal A-fibres. It is possible that in gastroparesis, stimulation of the vagus nerve as it traverses the neck might influence symptoms.
Methods Fifteen patients with severe gastroparesis awaiting Enterra (Medtronic, Minnesota) implantation agreed to a short proof of concept assessment of nVNS. Each patient was supplied with a GammaCore device programmed to deliver 150 doses, each dose lasting 90 seconds. The electrodes on the GammaCore device were positioned in line with the right cervical vagus nerve and stimulation applied three times daily. The gastroparesis multi-symptom questionnaire, that includes the symptoms of nausea, vomiting, early satiety and bloating, was completed daily for the week prior to starting treatment and daily throughout the treatment period. Symptoms were scored on a Likert scale (1 = none and 5 = severe). Composite and individual symptom scores were summated for the week preceding treatment and the final two weeks of the treatment period.
Results Only seven of the 15 patients complied with the treatment regimen. In six patients, the diary score cards were incomplete and two patients did not use the GammaCore.
Conclusion In this group of severely ill patients awaiting Enterra implantation, half complied with the treatment regimen. Compliant patients scored improvement in nausea, early satiety and bloating, as well as the composite gastroparesis score. This short term proof of concept assessment suggests that nVNS influences symptoms conveyed by vagal afferents. It is possible that stimulation of both left and right vagus nerves, increased stimulation amplitude, and a longer period of treatment might improve responsiveness. Future clinical trials are warranted to elucidate safety, efficacy, dose response and compliance.
Disclosure of Interest None Declared.