Computed tomography is useful for preoperative identification of nonrecurrent laryngeal nerve in thyroid cancer patients

Objective. Nonrecurrent laryngeal nerve (NRLN) is a risk factor for nerve injury during thyroid or parathyroid surgery and is usually associated with vascular anomalies. This study investigated the usefulness of computed tomography (CT) scans for preoperative identification of NRLN in thyroid cancer patients. Study Design. Case series with chart review. Setting. Academic university hospital. Subjects and Methods. Of the 6546 patients, 20 (0.3%) were intraoperatively identified with NRLN, and the medical records of 20 patients were reviewed retrospectively, with particular focus on preoperative CT findings. Results. All 20 cases were right-sided NRLN, and no clinical symptoms were observed preoperatively in any patient. Two patients had type I NRLN and 18 had type II NRLN. NRLN injury occurred in 1 patient at a point where the nerve was close to the superior thyroid artery. Prior to surgery, surgeons identified only 5 suspected NRLN cases based on identification of vascular anomalies on CT scans. However, this review of CT scans revealed that vascular anomalies could be identified on the scans of all patients. Conclusions. Neck CT scanning appears to be an excellent method for predicting NRLN cases. However, thorough examination of the scans, with particular attention to the neck and mediastinum vascular structures, is required.