EndoStim’s lower esophageal sphincter electrical stimulation system improved reflux symptoms and reduced esophageal acid exposure in patients with gastroesophageal reflux disease who did not respond well to proton pump inhibitors, according to interim results from a prospective, international, multicenter, open-label study.
“EndoStim's neurostimulation therapy is a minimally-invasive, long-term treatment for severe reflux patients that directly targets the patient's weak or dysfunctional lower esophageal sphincter (LES) muscle between the stomach and the esophagus — often the underlying cause of reflux,” according to a press release. The system includes an implantable pulse generator (IPG) and a bipolar stimulation lead with two stitch electrodes connected to the IPG. It is CE marked for GERD patients whose symptoms persist for at least 6 months, and is available in a number of European, Latin American and Asian Pacific countries, but “is not approved for sale in the U.S. and is limited by U.S. federal law to investigational use only.”
Peter D. Siersema
Peter D. Siersema, MD, PhD, chief of the department of gastroenterology and hepatology at the University Medical Center, Utrecht, the Netherlands, and colleagues report 6-month data from 41 GERD patients who were partially responsive to PPIs and underwent laparoscopic implantation of the LES electrical stimulation therapy (EST) system at 10 sites in eight countries. They measured GERD health-related quality of life (HRQL), daily symptom diaries, quality of life scores, esophageal acid exposure and LES resting and residual pressure before and after therapy was administered.
The standard therapy protocol involved 30-minute sessions with 90-minute breaks 12 times a day at 5 mA, 20 Hz, 220 µs pulse width, which was altered based on persistent symptoms or acid exposure during follow up. Stimulation began within 48 hours after implantation in 37 patients, and after 2 weeks in a subset of five patients in whom a significant hiatal defect was repaired to allow the electrode implant site to heal after esophageal hiatus dissection.
“Our results show uniformity in outcome across multiple centers as well as consistency with the results reported in a single center study with published results up to 2 years of follow-up,” Siersema said in the press release.
Serious adverse events included a device-related event, a procedure-related event and an unrelated event. Median GERD-HRQL increased from 31 (IQR = 26.2-36.8) off-PPIs and 16.5 (IQR = 9-22.8) on-PPIs to 4 (IQR = 1-8) at 3 months and 5 (IQR = 3-9) at 6 months (both P < .0001). Median esophageal acid exposure (pH < 4.0) was reduced from 9.9% (IQR = 7.5-12.9) to 3.8% (IQR = 1.9-12.3) at 3 months (P = .0027) and 4.4% (IQR = 2.2-7.2) at 6 months (P < .0001).
A total of 16 patients underwent hiatal repair and had a comparable response to therapy as patients without a hiatal defect. “This is an important finding because now we can consider EndoStim therapy in those patients with significant hiatal defects by combining EndoStim with a simple hiatal repair procedure,” Carsten Gutt, MD, chief of surgery at Klinikum Memmingen, Germany, said in the press release.
“In conclusion, these 6-month interim results show an acceptable safety profile of LES electrical stimulation to date, combined with good short-term efficacy in the treatment of GERD,” the researchers wrote. “The marked reduction in regurgitation episodes, without the risk of intervention-requiring dysphagia, is a potentially important advantage of LES stimulation over other existing anti-reflux procedures.” – by Adam Leitenberger
Disclosure: Siersema reports he has served as a consultant, speaker and member of the advisory board for EndoStim. Please see the study for a full list of all other authors’ relevant financial disclosures. Gutt is lead investigator of a separate EndoStim trial that is currently recruiting, according to clinicaltrials.gov.