Monitoring the Bifurcated Recurrent Laryngeal Nerve

Anatomical anomalies of the recurrent laryngeal nerve (RLN) can not only mean an operational challenge in thyroid operations for the endocrine surgeon, but also an increased risk of postoperative vocal cord paralysis (VCP). Atypical courses of the RLN are frequent and observed in about a quarter of the thyroid gland operations. Anatomical RLN variations are represented by an atypical RLN pattern as anterior or lateral to the thyroid gland, an anteriorly RLN to a Zuckerkandl tuberculum nodule, a fixed, splayed, or entrapped RLN with capsular association through fascial bands, an invaded RLN, a nerve posterior to ligament of Berry, a thin <1 mm nerve, or antevascular RLN, a non-RLN, a ramificated RLN. Anatomical variations of RLN rarely can be identified preoperatively. The bifurcated RLN represent a significant anatomical variation because prevention of VCP requires preservation of all branches of the RLN. An awareness of the surgical anatomy and the possible dispositions and ramifications of the RLN is very helpful in avoiding its injury during thyroidectomy. The current report derives from a review of the literature and personal experience on identification, confirmation, and monitoring the bifurcated RLN.