THE AMAZINGLY and delicately coordinated intrinsic muscular complex of the larynx makes it a most remarkable organ. The permanent interruption of any of its motor nerve fibers brings about observable alterations of the movements of the arytenoid cartilages. The injury of both recurrent laryngeal nerves is rare, but unfortunately, must be considered an inevitable complication of thyroid surgery. The incidence, clinical behavior, and immediate and long-term treatment of bilateral vocal cord paralysis has been reviewed in a previous communication.1
Fundamental to this discussion is the behavior of paralyzed vocal cords. Whenever the arytenoid cartilages lose all of their muscular control, they drop downward with a slight rotation that carries the body of the cartilages forward and brings the vocal processes toward or beyond the midline. In bilateral paralysis, the obstruction to inspiration may develop in the immediate postoperative period or may not appear for several weeks after the nerves