The anatomy of the inferior laryngeal nerve.

Contradictory opinions are found in the literature concerning the precise anatomy and role of the inferior laryngeal nerve, the terminal portion of the recurrent laryngeal nerve. Moreover, operative damage to this nerve beyond the thyroid area is seldom described. Twenty-one human larynges were dissected to give a precise description of the inferior laryngeal nerve and to draw attention to the risks of injury to the nerve during specific laryngological operations. In contrast with the varied descriptions found in the literature, only small variations in the terminal branching of the nerve were found. The nerve divides generally extralaryngeally into two branches: a motor, anterior one, innervating the intrinsic laryngeal musculature (except the cricothyroid muscle), and a sensory, posterior one, forming Galen's anastomosis. The anterior branch of the nerve is particularly susceptible to damage just behind the cricothyroid joint; two of its terminal rami, supplying respectively the interarytenoid and thyro-arytenoid muscles, incur potential risks of injury during endoscopic CO2 laser surgery.