Ansa Cervicalis and Hypoglossal Nerve Stimulation in a Patient With Obstructive Sleep Apnea

Abstract

Hypoglossal nerve stimulation (HNS) is an alternative surgical therapy for individuals who are intolerant to positve airway pressure but have obstructive sleep apnea (OSA) that ventrally protrudes the tongue, although it may be insufficient in individuals with greater susceptibility to airway collapse. The pharynx is also distensible axially. Evidence suggests that caudal tracheal traction physiologically supports pharyngeal patency, but modern surgical techniques for OSA, including HNS, do not modify the airway caudally. Tracheal traction is primarily mediated by lung expansion, but infrahyoid cervical strap muscles, innervated by the ansa cervicalis, also exert a caudal pull on the pharynx. Physiologic experiments in animals have demostrated substancial impacts on pharyngeal patency, especially with stimulation of the sternothyroid muscle...