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The Role of Gastric Electrical Stimulation in Treating Refractory Vomiting: Recent Research Context

– GES may be of clinical benefit outside the context of gastroparesis


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Medical Today

Expert Critique

FROM THE ASCO Reading Room
Melinda Engevik, PhD
Melinda Engevik, PhD Postdoctoral Fellow Baylor College of Medicine
Full Critique

Chronic intractable vomiting is one of gastroenterology's most, with considerable financial, emotional, and quality-of-life consequences for patients. Still poorly understood, the condition presents a when low-fat, high-fiber diets and medications such as antidepressants and prokinetics fail to improve symptoms. Impaired nutritional status and weight loss may result.

Nausea occurring at least once a week has been observed in approximately 3% of the general population, while vomiting at least monthly without an underlying organic cause is reported by 2% of women and 3% of men. Interestingly, among patients with typical symptoms suggestive of gastroparesis, delays in stomach emptying are detected in only undergoing gastric scintigraphy.

Gastric electrical stimulation (GES) is a therapeutic option for refractory vomiting, with or without gastroparesis, but trials have yielded and placebo responses and cognitive influences have affected outcomes.

Most open-label cohort studies have reported that GES relieved nausea and vomiting. "Whether this is related to a placebo effect has not yet been firmly ruled out," said Guillaume Gourcerol, MD, of Rouen University Hospital in France, in an interview with the Reading Room. Gourcerol coauthored a study on a recent large, multicenter, randomized, double-blind trial of cross-over design published in

Up until now, GES efficacy has been studied in only three small randomized controlled trials that compared patients with their implanted stimulator turned either on or off in double-blind fashion, Gourcerol explained. Two of these trials were negative, while the third was positive in a post-hoc analysis.

Against that background, Gourcerol's team initiated the four-months-on, four-months-off study of 172 patients, in which high-frequency GES significantly reduced the occurrence of severe refractory vomiting and nausea in both diabetic and non-diabetic patients, with or without gastroparesis. In the face of nutritional deficiency, the only other options for these medically refractory patients were nasojejunal tube feeding or jejunostomy.

During the active "on" phase of GES, 30.6% of study patients reported at least a one-point improvement on a newly developed vomiting frequency scale versus 16.5% of patients during the "off" period, dropping from several episodes a day to fewer than one per week. "Therefore, this therapy can be offered to patients after failure of standard care," Gourcerol told the Reading Room. More than half of patients, however, reported no change in symptoms, suggesting that not all will benefit.

By way of mechanism, previous studies hypothesized that GES could restore the activity of the natural gastric pacemaker, Gourcerol explained, but in the present study it had no effect on gastric electrical activity or motility. "The efficacy of GES is therefore unrelated to acceleration of the gastric emptying rate, and some studies have suggested that the clinical efficacy is more related to a 'sensitivity effect.' By increasing the discomfort threshold for gastric distension, it prevents vomiting by allowing patients to better tolerate their food after a meal."

The study suggested that GES can help symptomatic patients without gastric motility disorders, and hence should not be restricted to patients with gastroparesis, Gourcerol said. In the U.S., however, GES is FDA approved only for gastroparesis, and the technique is expensive, including the device, surgery, and hospitalization. Offsetting these concerns, a recent French study suggested that the technique is cost-effective over the long-term, decreasing the direct and indirect costs of intractable nausea and vomiting by the equivalent of $3,000 to $5,000 per patient per year, he said. Another cost-effectiveness analysis on GES in diabetes patients with gastroparesis by found that GES reduced days in hospital by 61% in the first year, with the treatment emerging as cost-effective at the two-year horizon.

Stressing that the study was carried out in severely refractory patients "at the end of the road" of medical management, Gourcerol's group wrote, "The present results make sense in terms of clinical care, showing that a limited number of medically resistant patients may benefit from GES to relieve nausea and vomiting."

The authors cautioned, however, that more studies are needed to identify predictive factors of favorable response and to determine the technique's cost-effectiveness.

The GES study was supported by a grant from the French government. Several study authors, including Gourcerol, reported ties to industry.

Primary Source

Gastroenterology

Source Reference:

AGA Publications Corner

AGA Publications Corner