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Gastric electrical stimulation device may improve refractory vomiting

Use of gastric electric stimulation is a controversial therapy for gastroparesis. The Enterra Gastric Electric Stimulator System received FDA approval under a Humanitarian Device Exemption in 2000 considering the device to be safe and of probable benefit. Enterra had been shown to decrease vomiting frequency in patients with medication refractory gastroparesis. Subsequent studies performed for approval for efficacy did not meet their predefined endpoint. Some physicians use this as treatment for their patients with refractory gastroparesis under the HDE and with institutional review board approval; many physicians do not.

Dr. Henry P. Parkman

The article by the French group brings support for gastric electric stimulation in a double blind study that showed gastric stimulation significantly reduced nausea and vomiting, both in diabetic and nondiabetic patients and in both those with delayed and normal gastric emptying.

The NIH Gastroparesis Clinical Research Consortium recently reported the symptom response with gastric stimulation for clinical care of patients with gastroparesis, compared with those who did not receive this treatment. In this observational study in multiple practice settings, 15% of patients with symptoms of gastroparesis in the NIH registry underwent gastric stimulation. Patients with more severe overall symptoms were more likely to improve symptomatically over 48 weeks, primarily because of reduction in nausea severity.

In the last 5 years, pyloromyotomy for gastroparesis has reemerged as a treatment for gastroparesis, especially when performed endoscopically (G-POEM or POP). Multiple studies, primarily single-center studies, support this treatment in improving gastroparesis symptoms and gastric emptying, though placebo-controlled studies have not been performed.

When should one perform gastric electric stimulation versus pyloromyotomy? At our center, we perform both stimulator placement and pyloromyotomy procedures in patients with refractory gastroparesis symptoms with delayed gastric emptying. We find that patients with refractory symptoms of gastroparesis undergoing stimulator placement, pyloromyotomy, or combined stimulator with pyloromyotomy each had improvement of their gastroparesis symptoms. Gastric stimulation and combined stimulator with pyloromyotomy improved nausea/vomiting, whereas pyloromyotomy alone tended to improve early satiety and postprandial fullness.

Presently, our clinical protocol for patients with refractory gastroparesis (not responding to metoclopramide, domperidone, granisetron patch, mirtazapine) is the following:

  • If nausea and vomiting are particularly severe, we proceed with gastric stimulation.
  • If gastric emptying is significantly delayed especially with symptoms of early satiety, patients undergo pyloromyotomy.
  • If patients have significant nausea and vomiting with markedly delayed gastric emptying, patients get both stimulator placement and pyloromyotomy.

Studies are currently being performed to evaluate this type of patient-oriented management approach.

Henry P. Parkman, MD, gastroenterologist, gastroenterology section, Temple University, Philadelphia. He has no conflicts of interest.


 

FROM GASTROENTEROLOGY

An implanted gastric electrical stimulation device significantly improved refractory vomiting but not quality of life in a randomized, multicenter, double-blind crossover trial of 172 patients.

After 4 months of electrical stimulation, frequency of vomiting was significantly improved from baseline in the intervention arm, compared with the control arm, in patients with both delayed (P less than .01) and normal (P = .05) gastric emptying. There was also an improvement in nausea with gastric stimulation. In contrast, there was no significant improvement in the coprimary endpoint of quality of life. Based on these findings, “a limited number of medically resistant patients may benefit from gastroelectric stimulation to relieve nausea and vomiting,” wrote Philippe Ducrotté, MD, of Rouen (France) University Hospital and associates in Gastroenterology.

High-frequency gastric electrical stimulation with the surgically implanted Enterra device is regarded as a treatment option for chronic refractory vomiting in patients with or without gastroparesis. However, only moderate evidence supports the use of this therapy, with level 1 evidence limited to a single study, according to the researchers. For the study, they enrolled 172 adults with at least 12 months of nausea or vomiting that was refractory to antiemetic or prokinetic therapy and was either idiopathic or related to type 1 or 2 diabetes mellitus or surgery (partial gastric resection or vagotomy). Symptoms “had to be severe enough to affect the general condition of the patient, including [causing] weight loss, or the need to change dietary intake to control diabetes,” said the researchers.

The study started with a 4-month run-in period, after which all patients had the device implanted and left off for one month. Patients in the intervention arm then had the device turned on and programmed at standard parameters (5 mA, 14 Hz, 330 micros, cycle on 0.1s, cycle off 5s). Both groups were assessed at 4 months, and 149 patients then crossed over to the other arm and were assessed again at 4 months. Vomiting was evaluated on a 5-point scale ranging from 0 (most severe) to 5 (symptom absent), while quality of life was assessed by means of the 36-question, self-administered Gastrointestinal Quality of Life Index (GIQLI).

During the intervention, 30.6% of patients reported at least a 1-point improvement on the vomiting frequency scale, while 53% reported no change. With the device turned off, 16.5% of patients reported an improvement in vomiting. During both phases of the trial, median vomiting frequency score was improved in the intervention arm compared with the control arm (P less than .001) in patients with (42%) and without (58%) diabetes. “Gastric emptying was not accelerated during the on period compared with the off period,” the investigators wrote.

A total of 133 (77%) patients in the study had gastroparesis. Most patients were women in their 40s who vomited several times per day. Among 45 device-related events, the most common was abdominal pain at the implantation site (62%), followed by “infectious problems” at the abdominal pouch level (36%) and hematoma (2%). Three of these events “were serious enough to prompt device removal,” the researchers wrote.

The French government funded the study. The investigators reported having no conflicts of interest. They dedicated the paper to the memory of Dr. Ducrotté, who died during the course of the study.

*This story was updated on January 13, 2020.

SOURCE: Ducrotté P et al. Gastroenterology. 2019 Oct 1. doi: 10.1016/S0016-5085(17)30875-2.

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