Objective: To assess the efficacy and durability of upper airway stimulation via the hypoglossal nerve on obstructive sleep apnea (OSA) severity including objective and subjective clinical outcome measures.
Study design: A randomized controlled therapy withdrawal study.
Setting: Industry-supported multicenter academic and clinical setting.
Subjects: A consecutive cohort of 46 responders at 12 months from a prospective phase III trial of 126 implanted participants.
Methods: Participants were randomized to either therapy maintenance ("ON") group or therapy withdrawal ("OFF") group for a minimum of 1 week. Short-term withdrawal effect as well as durability at 18 months of primary (apnea hypopnea index and oxygen desaturation index) and secondary outcomes (arousal index, oxygen desaturation metrics, Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire, snoring, and blood pressure) were assessed.
Results: Both therapy withdrawal group and maintenance group demonstrated significant improvements in outcomes at 12 months compared to study baseline. In the randomized assessment, therapy withdrawal group returned to baseline, and therapy maintenance group demonstrated no change. At 18 months with therapy on in both groups, all objective respiratory and subjective outcome measures showed sustained improvement similar to those observed at 12 months.
Conclusion: Withdrawal of therapeutic upper airway stimulation results in worsening of both objective and subjective measures of sleep and breathing, which when resumed results in sustained effect at 18 months. Reduction of obstructive sleep apnea severity and improvement of quality of life were attributed directly to the effects of the electrical stimulation of the hypoglossal nerve.
Keywords: OSA; hypoglossal nerve; obstructive sleep apnea; randomized controlled trial; sleep; sleep apnea; surgery; treatment; upper airway stimulation.
© American Academy of Otolaryngology-Head and Neck Surgery Foundation 2014.