Iatrogenic Nerve Injuries in Head and Neck Surgeries: A Systematic Review of Mechanisms, Outcomes, and Prevention Strategies

Iatrogenic nerve injury in head and neck surgery remains a substantial yet potentially preventable source of morbidity across endocrine, otolaryngologic, and related procedures. This systematic review synthesized evidence to identify the nerves most frequently affected, delineate operative mechanisms of injury, describe the clinical course, and evaluate preventive strategies. Traction on visually intact nerves emerged as the predominant mechanism, with additional contributions from thermal injury, compression, ischemia, and entrapment by suture or clip. The recurrent laryngeal, facial, trigeminal (inferior alveolar and lingual), spinal accessory, and lower cranial nerves were identified as the principal structures at risk, with procedure type influencing the pattern and severity of deficits. Prevention centered on deliberate visual identification, meticulous dissection along natural planes, and risk-stratified use of intraoperative nerve monitoring, which proved most beneficial in complex or reparative fields. While most postoperative deficits resolved over time, a subset persisted, impairing voice, swallowing, facial movement, shoulder function, or orofacial sensation. Early, tension-free microsurgical repair was associated with superior recovery compared to delayed intervention. Despite heterogeneity in definitions, assessment timing, and follow-up, these findings support a practical prevention framework that integrates precise anatomical techniques, gentle handling, structured monitoring in high-risk cases, and timely referral for persistent deficits to minimize avoidable nerve injury and improve long-term outcomes.