A rare case of the right-sided aortic arch that has the right subclavian artery as the last branch.

This report describes a rare case of the right-sided aortic arch with the right subclavian artery as the last branch, which was encountered in a Japanese male cadaver in the dissecting room at Kurume University School of Medicine in 1995. In this subject, the ascending aorta arose from the left ventricle and ascended obliquely, curving forward and to the right, and became the right-sided aortic arch. The aortic arch passed upwards, reaching a summit at the level of the third thoracic vertebral body, then curved dorsally. The left brachiocephalic, the right common carotid and the right subclavian arteries came off the aortic arch in that order. After the right subclavian artery, the aortic arch dilated and formed the aortic diverticulum behind the trachea and the esophagus. The right thoracic aorta, a continuation of the aortic arch, descended to the right of the vertebral column. This case is a type M anomaly according to the Adachi-Williams-Nakagawa's classification, and is the twelfth case with this type of vascular variation to be reported in Japan.