Hypoglossal Nerve Stimulation: Effective Longterm Therapy for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a worldwide health problem. Historically, OSA was believed to be primarily anatomical in origin due to excess tissue obstructing the airway. Uvulopalatopharyngoplasty, the most common surgical approach, was aimed at resecting or ablating this tissue but failed to resolve OSA in 59% of patients. Contemporary research focuses on physiologic contributors to OSA, such as impaired airway dilator activity and failure of the neuromuscular feedback loop. Hypoglossal nerve stimulation is a new treatment option for eligible patients that addresses this neurofeedback-loop dysfunction. The hypoglossal nerve stimulator (Inspire Medical Systems, Maple Grove, MN) includes an implantable pacemaker-sized pulse generator that senses chest wall movement during sleep and contracts the genioglossus muscle via stimulation of the hypoglossal nerve. Genioglossus contraction gently protrudes the tongue, which enlarges the retrolingual and retropalatal levels of the airway. Early studies of the efficacy of hypoglossal nerve stimulation showed that apnea-hypopnea index scores decreased by 68% 12 months after stimulator implantation, with recipients reporting decreased sleepiness and OSA effects, and improved quality of life. Four-year follow-up results indicate ongoing effectiveness of therapy with regard to subjective measures of quality of life. To date, this device has been implanted in more than 1,800 patients.