Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea: Device Systems, Surgical Technique, and Clinical Outcomes

Background and Objectives: Hypoglossal nerve stimulation (HGNS) has emerged as an effective alternative therapy for patients with obstructive sleep apnea (OSA) who fail or cannot tolerate positive airway pressure (PAP) therapy. This review summarizes the system design, implantation techniques, indications, contraindications, and clinical outcomes of currently available HGNS systems, focusing on the Inspire® upper airway stimulation system and the Genio® system. Materials and Methods: A comprehensive synthesis of device architecture, surgical procedures, patient selection criteria, and evidence from major clinical trials was performed. Comparative evaluation included device components, stimulation principles, perioperative considerations, and long-term efficacy and safety profiles. Results: The Inspire® system employs unilateral stimulation via an implantable pulse generator, respiratory sensing lead, and stimulation lead, requiring multistep implantation with selective medial branch of hypoglossal nerve targeting. In contrast, the Genio® system provides bilateral, lead-less stimulation through a single submental implant powered externally, eliminating the need for thoracic leads and intramuscular cuff dissection. Clinical studies including STAR, ADHERE, and BLAST-OSA demonstrate significant reductions in apnea–hypopnea index, oxygen desaturation index and daytime sleepiness, with high adherence rates and sustained long-term benefits. Complications are generally mild, with low rates of device-related serious adverse events. Conclusion: HGNS represents a validated, durable, and patient-centric treatment modality for moderate-to-severe OSA, particularly in PAP-intolerant patients without complete concentric palatal collapse. Inspire® and Genio® system differ substantially in surgical approach and device design, offering complementary therapeutic options tailored to patient anatomy, comorbidities, and lifestyle considerations. Continued refinement of technology and expanding indications are expected to broaden clinical applications in future.