Upper airway stimulation for Obstructive Sleep Apnoea (OSA): A new paradigm of treatment

Obstructive Sleep Apnoea (OSA) is a chronic condition, caused by anatomical factors associated with a progressive loss of muscular tone of the tongue and pharyngeal walls, producing upper airways collapse with oxygen desaturation during sleep. Hypoglossal nerve stimulation (HNS) is an innovative and physiological technique, with validated positive effects, to treat patients with OSA who have failed or refused continuous positive airway (cPAP) standard therapy. HNS is a mixed medical and surgical procedure consisting of an electrical stimulation of the medial branches of the hypoglossal nerve—activating the genioglossus muscle (GM) that is the primary protrusor muscle of the tongue—by an implanted cuff electrode connected to a pulse generator and to a respiratory-sensing lead. The purpose of HNS is to increase the neuromuscular activity and the tone of the tongue during sleep in order to avoid upper airway collapse and improve airflow. Compared to traditional surgical procedures, HNS is more conservative and produces a titratable and potentially reversible activation of upper airway dilatators muscles, without definitive anatomical modifications. A strict multidisciplinar approach, from patient clinical evaluation to neurostimulator programming and follow-up, is of crucial importance to achieve a successful implantation. Limitations of HNS are the uncertainty about the long-term adherence and effectiveness and high costs of the device. Further clinical studies are needed to improve the technological features of the current devices and to optimize patients selection criteria in order to identify best responders and to achieve higher cure rates.