Non-recurrent laryngeal nerve related to thyroid surgery: a report of 5 cases and literature review.

Background: Non-recurrent laryngeal nerve, a rare anomaly, passes transversely into larynx with or without its recurrent branches directly arising from the vagus nerve. The paper investigates clinical significance of non-recurrent laryngeal nerve during thyroid surgery. Clinical data from 5 cases of non-recurrent laryngeal nerve and related literature reviews were made to acknowledge its incidence, variant types and matters concerned during thyroid operations.

Case Report: 821 recurrent laryngeal nerves were anatomized during 2496 thyroid operations, from which 5 were confirmed to hold non-recurrent laryngeal nerves (0.61%). 3 patients were found to have non-recurrent laryngeal nerves during re-operation because of voice horse after the first operation which improved much after re-operation. The other two patients were recognized during the first operation. All 5 cases were not diagnosed preoperatively.

Conclusions: Non-recurrent laryngeal nerve, a rare anomaly, is very vulnerable during thyroid surgery. It is helpful to avoid injuring non-recurrent laryngeal nerve that identification of the non-recurrent laryngeal nerve and its types.