The nonrecurrent laryngeal nerve in thyroid surgery

Abstract

A nonrecurrent laryngeal nerve is a rare anomaly and estimated to be present in 0.25 to 0.99% of patients.1 The identification and preservation of the recurrent laryngeal nerve is an essential part of thyroid surgery. It is now well-known that the recurrent laryngeal nerve is not only a single nerve but also a complex branching network of innervation. Thyroid surgery demands a precise understanding of the anatomical intimacy between the gland and surrounding structures, including the parathyroid glands and neurovascular tissue. The morbidity associated with thyroid surgery, in the short-term, generally relates to hematoma collection and hypocalcemia. Long-term morbidity is more commonly seen with dysphonia and vocal cord dysfunction due to superior laryngeal nerve damage and its role in explosive sound formation, the recurrent laryngeal nerve, its tortuous anatomical course, and its role in laryngeal musculature innervation. We review the literature on this subject and report three cases of the rare nonrecurrent anomaly, firstly a 75-year-old lady with a large retrosternal goiter. During her initial work-up which included a CT scan of the thorax, an 'arteria lusoria' was identified in the retroesophageal plane. Intraoperatively, a right-sided nonrecurrent inferior laryngeal nerve (NRILN) was identified. The second case is of a 63-year-old lady with a right-sided type 1 nonrecurrent laryngeal nerve which we identified and photographed when medially retracting the gland off the central compartment and ligament of Berry. The third case is that of a 45-year-old lady with a right-sided thyroid nodule and a right-sided NRILN identified intraoperatively. © Jaypee Brothers Medical Publishers (P) Ltd.