PROGRAM DESCRIPTION: This panel presentation provides an updated evaluation of the significant variability of the surgical anatomy of the recurrent laryngeal nerve (RLN) during thyroid surgery and implications for risk of nerve injury. Updated prevalence data regarding the surgical anatomic details of the RLN, including intraoperative expected trajectory patterns and important clinical neural features, will be reviewed and compared to previous estimates in the literature as reported by the International RLN Anatomic Classification System. Correlation with nerve injury rates and types of nerve injuries will be discussed, as well as anatomic risk factors for intraoperative RLN injury. Cases will be presented to highlight potential anatomic factors affecting RLN injury rates and patient safety. The RLN has long been recognized as a critical anatomic structure for preservation in thyroid and parathyroid surgery to prevent significant postoperative morbidity. Depending on the degree of injury, patients can suffer from a wide range of symptoms, from various voice and swallowing complaints to airflow obstruction necessitating tracheostomy in the setting of bilateral RLN injury and resultant bilateral vocal cord paralysis. Not surprisingly, injury to the RLN is a major cause for medico-legal litigation against surgeons. Although the incidence of RLN injury is reportedly low in the literature, the true injury rate is believed to be underreported for a number of reasons. The greater the understanding of the variability and detailed surgical anatomy of the recurrent laryngeal nerve, the more information we have at our fingertips to tailor our operative technique to protect the RLN during thyroid surgery.OUTCOME OBJECTIVE 1: To better understand the anatomic variability of the recurrent laryngeal nerve (RLN) in thyroid surgery.OUTCOME OBJECTIVE 2: To identify correlates between the intraoperative anatomic details and electrophysiologic responses of the RLN.OUTCOME OBJECTIVE 3: To consider the possible patient safety implications of this updated surgical anatomic understanding of the RLN in thyroid surgery.BACKGROUND STATEMENT: New observations across diverse patient populations are reshaping our understanding of RLN surgical anatomy during thyroid surgery, with significant variability in the anatomic and intraoperative characteristics of the RLN, which can impact the risk of neural injury.