An anatomical study of the recurrent laryngeal nerve: its branching patterns and relationship to the inferior thyroid artery.

The aim of this study was to provide information about the morphology and topography of the recurrent laryngeal nerve (RLN), its external features and branches, as well as its relationship to the inferior thyroid artery, the inferior horn of the thyroid cartilage and the thyroid gland. The RLNs in 50 adult cadavers (100 sides) were dissected and analyzed. A communicating loop connecting one branch of the RLN to another or a twig originating from the cervical sympathetic trunk was present in 13 of 100 sides. A double left RLN appeared in 2 sides; a right non-recurrent inferior laryngeal nerve appeared in one side. All of the RLNs, including looped ones, bifurcated into laryngeal branches and extralaryngeal branches, with most of the former further dividing into the anterior and posterior branches entering the larynx. The relations of the RLN to the inferior thyroid artery, the inferior horn of the thyroid cartilage and the thyroid gland were inconstant. The information gained from this study will be of value in thyroid surgery.