Identification of the Recurrent Laryngeal Nerve

ANATOMICAL studies1have demonstrated that there is considerable variation in the course of the recurrent laryngeal nerve (RLN) in the human. The variability means that the nerve is in danger in operations on the neck.2,3The liability to accidental injury is increased when large thyroid tumor masses have displaced the nerve from its normal position. The anatomical studies of Schonbauer4demonstrated the extent of such dislocations of the nerve by large thyroid masses, particularly on the right side, where the nerve can at times be displaced anterior to part of the goiter. Extralaryngeal branching, which occurs in a significant proportion of people, poses a further problem. Reported series of thyroid operations describe a wide variation in incidence of recurrent laryngeal nerve injury. The limitation of anatomical means alone as a certain method for identifying and thereby protecting the nerve is reason to explore the possibility of technical