LAS VEGAS, Nevada — Over the course of 1 year in patients with gastroesophageal reflux disease (GERD), lower esophageal sphincter electrical stimulation (LES-EST) improved symptoms, lowered esophageal acid exposure, and reduced proton pump inhibitor (PPI) use. The treatment had no gastrointestinal side effects or adverse events, according to a study presented here at the American College of Gastroenterology (ACG) 2012 Annual Scientific Meeting and Postgraduate Course on October 23.

The therapy offers an option for patients who have been on PPIs but have found them ineffective or who desire to stop taking them due to side effects. "We're looking for a more natural way to block acid reflux, as opposed to blocking the acid pumps that are doing something physiologically — they're in the stomach for a reason," Michael Crowell, PhD, codirector of gastrointestinal physiology and motility at the Mayo Clinic in Scottsdale, Arizona, who was a coauthor of the study, told Medscape Medical News.

Over the short term, LES-EST has been shown to improve lower esophageal sphincter pressure and esophageal pH and to alleviate GERD symptoms in patients with GERD.

The researchers conducted an open-label pilot extension trial to determine its effectiveness out to a 1-year follow-up. The study included patients who had had at least a partial response to PPIs and had off-PPI GERD-health-related quality of life (GERD-HRQL) greater than 20, percent 24-hour esophageal pH of less than 4.0 for at least 5%, hiatal hernia ≤ 3 cm, and esophagitis less than Los Angeles classification grade D.

Patients were implanted with bipolar stitch electrodes, and an implantable pulse generator (EndoStim BV, The Hague, the Netherlands) was implanted using laparoscopy. EST treatment was conducted at 20 Hertz (Hz), 220 μs, 3 to 8 mAmp in 30 minutes; 6 to 12 sessions were administered. Patient evaluation involved GERD-HRQL questionnaires, symptom diaries, Short Form Health Survey (SF)-12, and esophageal pH testing. The researchers optimized stimulation sessions according to residual symptoms, pH data when available, and lead impedance at follow up.

Of 25 implanted patients (mean age, 53 years; standard deviation, 12 years; 14 men), 23 entered the 2-year extension trial and have completed their 12-month evaluation. At month 12, patients experienced improvements in median GERD-HRQL compared with both their on-PPI (9 vs 2, P = .002) and off-PPI (23.5 vs 2, P < .001) median GERD-HRQL. They also experienced improvement in their median 24-hour distal esophageal acid exposure (10.1 vs 3.1, P < .001), with 77% of patients achieving at least a 50% reduction or normalization of their distal esophageal acid exposure.

With the exception of 1 individual, all patients stopped regular use of PPIs. (Regular PPI use was defined as taking a PPI on more than 50% of days.) The researchers observed no unanticipated implantation- or stimulation-related adverse events. They observed no dysphagia, and manometry indicated that swallowing function was unaffected. Stimulation sensation was not strong.

"Over 12 months, we were pretty much able to get people off PPI therapy and to substantially reduce the esophageal acid exposure and heal a lot of the esophagitis with very few side effects," Dr. Crowell said.

"I think it is compelling information, but it's a big step [to prove efficacy]. They had no sham data. They are planning a sham, where it will be implanted, but the device won't turn on," noted Walter Coyle, MD, head of gastroenterology at the Scripps Clinic, La Jolla, California.

It also remains to be seen whether patients will be accepting of the implant. "[Does a patient] want to have surgery for something that doesn't fix, and have to carry a battery pack? If someone is desperate to get off PPIs, or they're only partially effective, it could be a great alternative," said Dr. Coyle.

The study was funded by EndoStim BV. Dr. Crowell is a consultant to EndoStim. Dr. Coyle has disclosed no relevant financial relationships.

American College of Gastroenterology (ACG) 2012 Annual Scientific Meeting and Postgraduate Course: Abstract 46. Presented October 23, 2012.

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