ACG: Implant Improves Idiopathic Chronic Nausea And Vomiting

LAS VEGAS, Oct. 25 -- An implanted device approved for treating the chronic nausea and vomiting associated with gastroparesis may also be useful relieving these idiopathic symptoms in patients with normal gastric emptying.

In a pilot study of 16 patients, 10 had a 50% or greater reduction in symptom severity after one year with the device, reported Richard W. McCallum, M.D., of the University of Kansas Medical Center in Kansas City, and colleagues, at the American College of Gastroenterology meeting here.

Chronic nausea and vomiting are hallmarks of gastroparesis, and the device studied is approved by the FDA for treating these symptoms in patients with gastroparesis. However, the participants in the current study had normal gastric emptying at enrollment, Dr. McCallum said.

The cause of their symptoms, which had not responded to standard treatment, was not known. Thirteen were women, and five were diabetic. Median age was 39 years.

Even when the underlying cause is unclear, chronic nausea and vomiting can result in weight loss, interfere with daily activities and quality of life, and can result in trips to the emergency room for hydration, Dr. McCallum said.

In the current study, all participants underwent surgical implantation of the device, which consists of two electrodes implanted nine cm to 10 cm above the pylorus. The electrodes are connected to a pulse generator inserted under the skin of the abdomen. Participants were followed for one year.

On a vomiting symptom severity scale of 0 to 4, the average score reported by participants at baseline was 3, compared with an average score of 2 at the one-year mark (P=0.001), the study found.

Similarly, on a scale of 1 to 4 for nausea, the group's score topped the scale at 4 at baseline, compared with an average score of 2 after one year (P=0.0001), the researchers reported.

In addition, average weight increased from 59 kg at baseline to 61 kg at the end of the study period (P=0.01).

On a 28-point total symptom score (0=lowest, 28=highest), which included upper GI symptoms, a quality of life score, and a physical composite score, participants improved from an average score of 18 at baseline to an average score of 8 after one year (P=0.0002). Ten of the patients (62%) had a 50% reduction or more in their total symptom score, the study found.

Despite relieving symptoms, the device did not prevent some patients from developing abnormally slow gastric emptying. About one-third of patients developed this condition during the study period, the researchers said. However, the study was not designed to test whether the device improved gastric motility.

One patient died at four months from complications of misdiagnosed anorexia nervosa, and one patient had the device removed at two months when the area around the pulse generator became infected, the authors said. No other adverse events were reported.

"In patients with normal gastric emptying and functional nausea and vomiting, high-frequency gastric electrical stimulation is effective in improving upper GI symptoms, quality of life, and nutritional status," the investigators concluded. "These data extend the indications for gastric electrical stimulation therapy in patients with chronic nausea and vomiting."

The study was supported by Medtronic, Inc, of Minneapolis, Minn., which markets the device.