Variations in origin of the superior thyroid artery: an update for the head and neck surgeon.

Head and neck surgeons must have a thorough knowledge of head and neck vascular anatomy and its variations. This case report documents a variation in the superior thyroid artery encountered during a neck dissection and discusses the surrounding literature. A 55-year-old female with squamous cell carcinoma of the tongue underwent a partial glossectomy, right level I-IV neck dissection and reconstruction with a radial forearm free flap. During the procedure, an arterial branch was encountered arising 2-3cm caudal to the common carotid bifurcation. This variant branch was shown to represent the superior thyroid artery. On review of the literature, various classification systems of the superior thyroid artery origin have been described. Awareness of such anatomical variation is vital for the head and neck surgeon to avoid unexpected complication.