Electrical stimulation therapy of the lower esophageal sphincter is successful in treating GERD: final results of open-label prospective trial

Abstract

Background: Electrical stimulation of the lower esophageal sphincter (LES) improves LES pressure without interfering with LES relaxation. The aim of this open-label pilot trial was to evaluate the safety and efficacy of long-term LES stimulation using a permanently implanted LES stimulator in patients with gastroesophageal reflux disease (GERD).

Methods: GERD patients who were at least partially responsive to proton pump inhibitors (PPI) with abnormal esophageal pH, hiatal hernia ≤ 3 cm, and esophagitis ≤ LA grade C were included. Bipolar stitch electrodes were placed in the LES and an IPG was placed in a subcutaneous pocket. Electrical stimulation was delivered at 20 Hz, 215 μs, 3-8 mA in 30 min sessions. The number and timing of sessions was tailored to each patient's GERD profile. Patients were evaluated using GERD-HRQL, daily symptom and medication diaries, SF-12, esophageal pH, and high-resolution manometry.

Results: 24 patients (mean age = 53 years, SD = 12 years; 14 men) were implanted; 23 completed their 6-month evaluation. Median GERD-HRQL scores at 6 months was 2.0 (IQR = 0-5.5) and was significantly better than both baseline on-PPI [9.0 (range = 6.0-10.0); p < 0.001] and off-PPI [23 (21-25); p < 0.001] GERD-HRQL. Median% 24-h esophageal pH < 4.0 at baseline was 10.1 and improved to 5.1 at 6 months (p < 0.001). At their 6-month follow-up, 91 % (21/23) of the patients were off PPI and had significantly better median GERD-HRQL on LES stimulation compared to their on-PPI GERD-HRQL at baseline (9.0 vs. 2.0; p < 0.001). There were no unanticipated implantation- or stimulation-related adverse events or untoward sensation due to stimulation. There were no reports of treatment-related dysphagia, and manometric swallow was also unaffected.

Conclusions: Electrical stimulation of the LES is safe and effective for treating GERD. There is a significant and sustained improvement in GERD symptoms, esophageal pH, and reduction in PPI usage without any side effects with the therapy. Furthermore, the therapy can be optimized to address an individual patient's disease.

Fig. 1

Trial Design and Follow-up. - in person visit; - phone visit

Fig. 2

a LES Stimulation System (EndoStim BV, the Netherlands) comprises an IPG (65 mm × 48 mm × 12 mm, weight = 49 g) that is implanted in the subcutaneous pocket in the anterior abdomen and the bipolar electrodes are implanted in the LES and connected to the IPG. b The programmer is used to wirelessly program the IPG using a radiofrequency signal

Fig. 3

LES electrode position and IPG implant location. Bipolar stitch electrodes are placed in the abdominal esophagus inline 1 cm apart. The lead is connected to the IPG that is implanted in the subcutaneous pocket in the anterior abdomen

Fig. 4

Significant improvement in median (IQR) GERD-HRQL composite score at months 3 and 6 compared to baseline on-PPI and off-PPI median GERD-HRQL composite scores. There was small but statistically nonsignificant improvement from month 3 to 6

Fig. 5

Change in median IQR distal esophageal pH on LES electrical stimulation from baseline to 3 months (n = 24) and 6 months (n = 23). Related sample Wilcoxon signed-rank test was used to compare the pH at various time points

Fig. 6

Median % daily diary days with symptoms of nocturnal and daytime regurgitation (A) and heartburn (B), and  % of the diary days with various severity levels of regurgitation (C) and heartburn (D) at 1, 3, and 6 months compared to the baseline