Neck ultrasound for prediction of right nonrecurrent laryngeal nerve

Background. Nonrecurrent laryngeal nerve (NRLN) is 1 of the important causes for nerve damage during neck surgery. The anomaly is almost associated with congenital vascular abnormally. Most neck vascular anomalies can be detected by ultrasound. Methods. Both 3.5-MHz and 10-MHz probe neck ultrasound scans were performed for 2330 patients undergoing thyroidectomy preoperatively. Absence of innominate artery (INA) was defined as positive with right NRLN. Results. Of 13 positive patients found by 10-MHz probe, 11 were also identified by 3.5-MHz probe, and proved to be with right NRLN during operation. Two false-positive patients (18%) found by 10-MHz probe were due to short INA and tortuous INA, respectively. The incidence of right NRLN was 0.47% in Chinese people. Both the sensitivity and specificity for predicting right NRLN by 3.5-MHz probe were 100%. Conclusion. A 3.5-MHz probe neck ultrasound scan can accurately demonstrate right NRLN. Applying this tool for neck surgery to reduce the nerve damage is highly advised.