Gastric electrical stimulation reduces vomiting in patients with refractory chronic vomiting and/or nausea, researchers report in a randomized trial published in the February issue of Gastroenterology.
Chronic nausea and vomiting are estimated to affect 2.2% of the adult population. For many patients, dietary changes and medical treatments do not improve symptoms, resulting in impaired nutritional status. Chronic vomiting episodes are often related to delayed gastric emptying (gastroparesis), in which vomiting is associated with dyspeptic symptoms, and weight loss. However, some patients have chronic vomiting despite normal gastric emptying.
High-frequency gastric electrical stimulation (GES) (Enterra therapy) is 1 treatment option for patients with chronic refractory vomiting, associated or not with gastroparesis, although its efficacy has been debated. The GES device is a neurostimulator, implanted under the skin and with lead wires implanted in the wall of the proximal stomach. No randomized trial of GES has been conducted in patients with refractory vomiting associated with normal gastric emptying.
Philippe Ducrotte et al studied the effects of GES in a double-blind, multi-center study of 172 patients with refractory vomiting with or without gastroparesis. The study participants, who had at least 1 year of nausea or vomiting refractory to antiemetic or prokinetic therapies (chlorpromazine, metopimazine, ondansetron, granisetron, domperidone, metoclopramide, or erythromycin), were randomly assigned to groups that received 4 months of gastric stimulation or no stimulation; then they crossed over to the other group for 4 months.
The authors found that vomiting frequency was significantly reduced during the device ON period. When the Enterra devices was on, the participants’ mean vomiting score was 2.2 ± 1.7 (median score, 2.0) vs a mean vomiting score of 1.8 ± 1.7 (median score, 1.0) when the device was off (P = .0009). During the ON period, 30.6% of patients reported at least a 1-point improvement in the vomiting score compared with the OFF period. The results were consistent among patients with delayed or normal gastric emptying and also among patients with or without diabetes.
However, gastric emptying was not accelerated during the on period, and gastric electrical stimulation was not associated with improved quality of life (see figure). The study did not address whether GES is effective for chronic nausea in the absence of vomiting.
Among other symptoms, the frequency of nausea was reduced and the quality of appetite was better during the ON period. However, symptoms such as abdominal pain and bloating did not differ significantly between the ON and OFF periods, in diabetic or nondiabetic patients. Some adverse events were also associated with GES treatment, such as pain (13 patients) or infection at the insertion site (16 patients); in 3 patients the device needed to be removed.
In an editorial that accompanies the article, Jan Tack et al discuss finding from 4 different controlled trials that have evaluated the efficacy of GES in patients with gastroparesis—results from these studies vary. Tak et al state that, considering the modest magnitude of the therapeutic benefit, the cost of the treatment, and the potential for adverse events with GES, it seems advisable to exhaust all therapeutic options, which include a large range of antiemetic and prokinetic agents, before considering GES. Tak et al list some other treatment options that might also be considered, such as mirtazapine, prucalopride, and aprepitant. Tak et al write that temporary, minimally invasive GES has been proposed and should be further explored.
Ducrotte et al conclude that GES is effective in reducing the frequency of refractory vomiting and nausea in a subset of patients with chronic vomiting. However, further studies are needed to identify factors associated with response and to determine the technique’s cost effectiveness.