title: Effect of electrical stimulation of the lower esophageal sphincter in gastroesophageal reflux disease patients refractory to proton pump inhibitors.
abstract: OBJECTIVE
  To evaluate the efficacy of lower esophageal sphincter (LES)-electrical stimulation therapy (EST) in a subgroup of patients that reported only partial response to proton pump inhibitors (PPIs) therapy, compared to a group of patient with complete response.
  
  
  METHODS
  Bipolar stitch electrodes were laparoscopically placed in the LES and connected to an implantable pulse generator (EndoStim BV, the Hague, the Netherlands), placed subcutaneously in the anterior abdominal wall. Stimulation at 20 Hz, 215 μsec, 3-8 mAmp in 30 min sessions was delivered starting on day 1 post-implant. Patients were evaluated using gastroesophageal reflux disease (GERD)-HRQL, symptom diaries; esophageal pH and esophageal manometry before and up to 24 mo after therapy and results were compared between partial and complete responders.
  
  
  RESULTS
  Twenty-three patients with GERD on LES-EST were enrolled and received continuous per-protocol stimulation through 12 mo and 21 patients completed 24 mo of therapy. Of the 23 patients, 16 (8 male, mean age 52.1 ± 12 years) had incomplete response to PPIs prior to LES-EST, while 7 patients (5 male, mean age 52.7 ± 4.7) had complete response to PPIs. In the sub-group with incomplete response to PPIs, median (IQR) composite GERD-HRQL score improved significantly from 9.5 (9.0-10.0) at baseline on-PPI and 24.0 (20.8-26.3) at baseline off-PPI to 2.5 (0.0-4.0) at 12-mo and 0.0 (0.0-2.5) at 24-mo follow-up (P < 0.05 compared to on-and off-PPI at baseline). Median (IQR) % 24-h esophageal pH < 4.0 at baseline in this sub-group improved significantly from 9.8% (7.8-11.5) at baseline to 3.0% (1.9-6.3) at 12 mo (P < 0.001) and 4.6% (2.0-5.8) at 24 mo follow-up (P < 0.01). At their 24-mo follow-up, 9/11 patients in this sub-group were completely free of PPI use. These results were comparable to the sub-group that reported complete response to PPI therapy at baseline. No unanticipated implantation or stimulation-related adverse events, or any untoward sensation due to stimulation were reported in either group and LES-EST was safely tolerated by both groups.
  
  
  CONCLUSIONS
  LES-EST is safe and effective in controlling symptoms and esophageal acid exposure in GERD patients with incomplete response to PPIs. These results were comparable to those observed PPI responders.
authors: Edy Soffer, Division of Gastroenterology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States.
authors: Edy
authors: E
authors: Soffer
authors: Edy Soffer, Division of Gastroenterology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States.
authors: Leonardo
authors: L
authors: Rodríguez
authors: Edy Soffer, Division of Gastroenterology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States.
authors: Patricia
authors: P
authors: Rodriguez
authors: Edy Soffer, Division of Gastroenterology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States.
authors: Beatriz
authors: B
authors: Gómez
authors: Edy Soffer, Division of Gastroenterology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States.
authors: Manoel G
authors: MG
authors: Neto
authors: Edy Soffer, Division of Gastroenterology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States.
authors: Michael D
authors: MD
authors: Crowell
keywords: Electrical stimulation; Gastroesophageal reflux; Lower esophageal sphincter; Proton pump inhibitors; Refractory gastroesophageal reflux disease