A double-masked, randomized, placebo-controlled trial of temporary endoscopic mucosal gastric electrical stimulation for gastroparesis

Abstract

Background: Endoscopically placed, temporary gastric electrical stimulation (tGES) may relieve symptoms of gastroparesis (Gp) and predict permanent gastric electrical stimulation (GES) outcomes.

Objective: To measure effects of 72 hours of temporary GES on Gp symptoms.

Design, setting, and patients: From 2005 to 2006, we conducted a hospital-based, randomized, placebo-controlled, crossover trial of two consecutive, 4-day sessions (session 1 and session 2), enrolling 58 patients (11 males, 47 females; mean age 46 years) with GP symptom histories of three etiologies (idiopathic, 38; diabetes mellitus, 13; postsurgical, 7).

Intervention: 72 continuous hours temporary GES was provided for group A during session 1, and for group B during session 2.

Main outcome measurements: Symptoms measured daily; gastric emptying, electrogastrography, and quality of life measured at baseline and session close.

Results: In session 1, vomiting decreased in both groups, but was greater with stimulation, resulting in a day 3 difference of -1.02 (95% CI, -1.62 to -0.42; P < .001). Scores did not return to baseline during washout; on day 4, the difference persisted at -1.08 (95% CI, -1.81 to -0.35; P = .005). In session 2, vomiting slightly decreased with stimulation and slightly increased without it; at day 8, the nonactivated group had nonsignificantly greater vomiting, 0.12 (-0.68 to 0.92; P = .762). An overall treatment effect of a slight, nonsignificant daily decrease in average vomiting scores, -0.12 (-0.26 to 0.03; P = .116), was observed by pooling stimulation effects across sessions.

Limitations: Missing data; potential physiological imbalances between groups.

Conclusions: Although overall treatment effects were not significant, differences in favor of stimulation were suggested. Barriers to observing treatment effects included a decrease in vomiting for both groups during session 1, insufficient washout, and the absence of baseline vomiting for some patients. Future studies should better define inclusion criteria, use longer washout periods, randomize by etiology and baseline physiological findings, and pursue alternative designs. (

Clinical trial registration number: 00432835.).

Copyright © 2011 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

Figures

Figure 1

Study flow diagrams. A, This study design and allocation schematic provides the data collection schedule for our double-masked, randomized, controlled trial from enrollment through evaluation across two 4-day sessions, for a total of 8 study days. B, The randomization process and study allocation for each group in our trial, along with reasons for which some patients did not complete the study, are provided. EGG, electrogastrogram; GET, gastric emptying time; QOL, quality of life.

Figure 2

Vomiting scores across the study. Vomiting scores over the course of the study are provided for both groups, with individual patient scores, daily means and smoothed average response trajectories along with 95% confidence bands. During session 1, a slight, non-significant decrease in average vomiting score was observed; however, the decrease with stimulation (group A) was greater. Scores did not return to baseline for either group during the washout period. During session 2, vomiting scores slightly decreased with stimulation (group B) and slightly increased without it (group A) (see Table 2).

Figure 3

Patients who had at least some initial vomiting at baseline reported improved symptoms with stimulation. Mean vomiting scores decreased for both groups with 72-hours active stimulation.

Figure 4

For patients with diabetic gastroparesis in both Groups A and B, improved symptoms were seen with stimulation. Mean vomiting scores decreased in Group A with 72-hours active stimulation, and then approached baseline levels when stimulation was terminated.

Figure 5

Vomiting symptoms experienced by group B patients with a cyclic symptom pattern were reduced with temporary GES ON. When treatment with temporary GES was withdrawn by switching OFF the device, vomiting symptoms worsened in this group.