Importance of pre-operative recognition of the nonrecurrent laryngeal nerve.

The nonrecurrent laryngeal nerve is vulnerable during thyroid surgery. Pre-operative recognition of this nerve allows surgeons to avoid injuring the nerve. This anomaly depends upon the aortic arch anomaly and, therefore, in some cases, surgeons are able to predict the presence of this nerve pre-operatively by chest X-ray or barium swallow. Two patients with nonrecurrent laryngeal nerve are reported, one of whom, a 48-year-old man, had an abnormal shadow of the aortic arch, which led to confirmation of a right aberrant subclavian artery. Barium swallow plays a decisive role in the diagnosis of nonrecurrent laryngeal nerve, and this test is mandatory in patients who complain of difficulty in swallowing.