In the clinical trial, 124 patients at 22 different hospitals in the United States and Europe were fitted with a pacemaker in their chest. The study was supported by the pacemaker's manufacturer, Inspire Medical Systems. The company also helped design the study alongside the researchers and regulators from the U.S. Food and Drug Administration.
With the device, an electrode runs from the pacemaker to the hypoglossal nerve located under the tongue. Another lead wire runs down to the muscles between the ribs of the chest and keeps track of the person's breathing.
The surgery is minimally invasive, and patients typically were back to regular activity within a day or two, said study co-author Dr. Ryan Soose, director of the division of sleep surgery at UPMC.
"It's a unique and promising new treatment," Soose said.
As the patient breathes in and out, the pacemaker sends electrical impulses to the nerve, which causes the person's tongue to move slightly forward and their upper airway to contract open. Both movements keep the airway from collapsing.
Patients only used the pacemaker during sleep, turning it on and off by waving a magnet over the implant.
"We found there was a very robust effect on sleep apnea," Strollo said. Patients experienced much fewer episodes of sleep apnea and received much more oxygen in their blood as a result.
The researchers also found that sleep apnea returned when patients were taken off the pacemaker treatment.
The technology also appears safe. It did no permanent damage to the patient's tongues, Strollo said, although two of five patients did report some discomfort associated with the electrical stimulation.
In an accompanying journal editorial, Dr. Atul Malhotra at the University of California, San Diego, noted that while the pacemaker appeared to reduce sleep apnea, it didn't eliminate it. He pointed out that the study lacked a comparison group, and that the results could have been due to other factors such as participants' diet or exercise.
An FDA panel will review findings from the clinical trial in February, Strollo said.
A number of teams have been researching this technology, said Dr. William Kohler, medical director of the Florida Sleep Institute. He was not involved with the new study.