The right-sided aortic arch with unusual course of bilateral recurrent laryngeal nerves: a report of rare variations.

We describe a rare case of the right-sided aortic arch, the unusual origin of the main arterial vessels and the unusual courses of bilateral recurrent laryngeal nerves in a Japanese cadaver. Chiefly, the right-sided aortic arch turned to the left side from the dorsal part of the trachea and esophagus, and Kommerell's diverticulum was found at the end of the arch. The right common carotid artery arose from the end part of the ascending aorta, but the left common carotid artery arose from the proximal portion of the ascending aorta. The right subclavian artery arose from the upper edge of the aortic arch, but the left one arose from the front wall at the upper side of the ligamentum arteriosum. The right recurrent laryngeal nerve hooked around the aortic arch (but not the right subclavian artery) dorsoventrally, and the left recurrent laryngeal nerve hooked around the ligamentum arteriosum and arose from the ventral side (but not dorsal) of the aortic arch. These variations are very rare, and understanding them is useful and important for clinical research.