Diagnosis of Nonrecurrent Laryngeal Nerve by CT Angiography

Objective Nonrecurrent laryngeal nerve (NRLN) is found in 0.5% to 1.0% of the entire population. NRLN mostly develops on the right an anomaly of the subclavian artery. Through 3 cases, we report a simple method to diagnose an anomaly of the right subclavian artery with NRLN. Method Case 1. A 52‐year‐old woman was admitted with a thyroid mass. After a neck CT and fine‐needle aspiration biopsy, she had an operation from thyroid papillary carcinoma. Intraopera‐tively, we found NRLN and preserved it. Case 2. A 33‐year‐old woman visited us with a cervical mass. She was diagnosed with thyroid follicular carcinoma. Intraoperatively, we found NRLN cut. Case 3. A 68‐year‐old woman complained of a recurring thyroid mass. Preoperatively, we predicted NRLN through CT angiography. Intraoperatively, we identified the right NRLN. Results In case 3, NRNL was expected through neck CT angiography. Intraoperatively we could find NRLN more easily than case 1 and 2. Conclusion If we can predict NRLN preoperatively, it will be possible to preserve NRLN easily. We can differentiate arteria lusoria from normal findings more precisely with neck CT angiography as compared with neck CT. We diagnosed NRLN preoperatively with neck CT angiography, and this was helpful for us to preserve RLN intraoperatively. We report the case that we identified and preserved NRLN more easily by predicting NRLN with neck CT angiography.