How effective and safe is hypoglossal nerve stimulation (HNS) as an alternative therapy in the treatment of obstructive sleep apnea (OSA)?
Background: The primary treatment course for OSA is therapy with continuous positive airway pressure (CPAP) devices. Despite efforts to improve adherence, only 40% to 60% of patients continue to use CPAP long term or as prescribed, and many others do not seek medical attention. Alternative therapies are often used after medical management has failed, and several projects have attempted to prove the usefulness of chronic HNS as a novel therapeutic approach.
Explore this issue:May 2015
Study design: Comprehensive literature search of six studies with 200 patients from April 1 through Sept. 5, 2014.
Setting: Scopus, PubMed, and Cochrane Library electronic databases.
Synopsis: Three types of HNS systems were analyzed in the included studies. Pooled fixed effects analysis showed the following impacts at three, six, and 12 months, respectively, for the following measurements: Apnea-hypopnea index (AHI): statistically significant reductions in mean difference (MD) of -23.94, -25.60, and -17.51, respectively; oxygen desaturation index (ODI): statistically significant reductions in MD of -10.04, -11.68, and -13.73, respectively; Epworth Sleepiness Scale (ESS): statistically significant reductions in MD of -4.04, -3.82, and -4.42, respectively. Overall, there were reductions seen in AHI and ODI at three months (54%/52%), six months (57%/52%), and 12 months (50%/48%). No significant heterogeneity was found in any of the comparisons, suggesting equivalent efficacy in AHI, ODI, and ESS reduction. There were no serious adverse events (any complication resulting in life-threatening illness or injury, or permanent impairment of body structure or function) and no deaths. Nine patients had serious device-related adverse events that led to stimulator removal. Limitations included a limited number of case series/case reports from a few highly experienced centers, a limited clinical follow-up duration, highly specific inclusion and exclusion criteria, lack of titration information, and a heterogeneous group of systems.
Bottom line: HNS therapy may be considered in selected patients with OSA who fail medical treatment, but further studies comparing HNS with conventional therapies are needed to definitively evaluate outcomes.
Citation: Certal VF, Zaghi S, Riaz M, et al. Hypoglossal nerve stimulation in the treatment of obstructive sleep apnea: a systematic review and meta-analysis. Laryngoscope. 2015;125:1254-1264.
—Reviewed by Amy Hamaker