The effect of neuromuscular stimulation of the genioglossus on the hypopharyngeal airway

Objectives: To determine the effects of neuromuscular stimulation (NS) of the genioglossus muscle on hypopharyngeal airway size. Study Design. Fourteen consecutively recruited healthy volunteers underwent percutaneous electrical NS of the genioglossus muscle. Methods: Bipolar hooked wires were inserted percutaneously into the genioglossus muscle and used for NS. The anterior-posterior diameter of the hypopharynx was measured at the level of the superior edge of the epiglottis at baseline and during NS from recorded video endoscopic examinations. Results: NS of the genioglossus muscle resulted in a significant increase in the diameter of the hypopharyngeal airway (P = .002) compared with baseline, ranging from a 33% to 284% increase in airway diameter. Three of the 14 patients demonstrated modest decreases in airway diameter, likely the result of faulty electrode placement in surrounding tongue retrusive muscles. Conclusions: NS of the genioglossus muscle was effective in increasing the hypopharyngeal airway and may provide a useful alternative to direct stimulation of the hypoglossal nerve with a nerve cuff electrode in the development of neuroprosthetic treatments for obstructive sleep apnea.