Implantable Device an Alternative to CPAP for Sleep Apnea?

A surgically implanted upper-airway stimulation device may provide an alternative for sleep apnea patients unable to tolerate continuous positive airway pressure (CPAP) therapy, according to a new study published in the New England Journal of Medicine.

While CPAP is the gold standard in obstructive sleep apnea (OSA) treatment, many patients are noncompliant or unresponsive to the therapy.

Researchers evaluated the clinical safety and effectiveness of upper-airway stimulation in treating moderate-to-severe OSA. Investigators recruited 126 patients for the two-part Stimulation Therapy for Apnea Reduction (STAR) Trial, which was sponsored by the device manufacturer.

The participants were patients with moderate-to-severe sleep apnea who had difficulty either accepting or adhering to CPAP therapy—83% were men and the mean age was 54.5 years.

The patients had a nerve-stimulating device implanted in their upper chest, which connected to a stimulation lead around a hypoglossal nerve and a sensing lead in the chest. The stimulation is designed to contract a patient’s upper airway muscles to keep the airways open and thus reduce the severity of OSA. The median time for surgical implantation was 140 minutes, and nearly 80% of patients were discharged the next day.

The rate of procedure-related serious adverse events was less than 2%. About a month after implantation, all of the patients had diagnostic polysomnographic testing before the device was activated. Once the device was activated, they were instructed about how to use a controller to initiate and terminate therapy on a nightly basis. The researchers evaluated them during outpatient visits at months 2, 3, 6, 9, and 12.

One year after device implantation, results showed a 68% reduction in apnea-hypopnea index scores and a 70% decrease in oxygen desaturation index scores—indicating fewer episodes of sleep apnea. Patients also reported improvements in quality of life and daytime sleepiness. At the 1-year visit, the investigators randomly assigned 46 consecutive participants who responded to therapy either to a therapy-maintenance group or a therapy-withdrawal group.

They turned the device off for 7 days in the therapy-withdrawal group, while patients in the therapy-maintenance group continued with the device on. Polysomnography testing indicated that episodes of apnea and hypopnea increased by 18 per hour in the therapy-withdrawal group, compared with only 2 per hour among those whose stimulators were left on.

—Colleen Mullarkey Reference Strollo PJ, Soose RJ, Maurer JT, de Vries N, Cornelius J, Froymovich O, et al. Upper-airway stimulation for obstructive sleep apnea. N Engl J Med. 2014;370(2):139-49.