Two case reports of the right-sided aortic arch

Two cases of right aortic arch with the left subclavian artery as its last branch were found in cadavers of 66- and 80-year-old Japanese males during the 1995 and 1996 dissection for students at Tokyo Dental College. In both cases, the esophagus and trachea were surrounded by a vascular ring which consisted of the aortic arch and arterial ligament. The left common carotid artery arose from the ascending aorta as the first branch and crossed ventral to the trachea in a left cephalic direction. In The second branch of the aorta, which was the right common carotid artery, the aortic arch ran in a dorsal direction, passing between the esophagus and vertebra after branch out the right subclavian artery. The left subclavian artery arose dorsal to the esophagus, and there was an aortic diverticulum between the left subclavian artery and the descending aorta. The arterial ligament communicated between the left pulmonary artery and the arterial diverticulum. The trachea and esophagus were consequently encircled by the vascular ring. Both of the present cases were of the N-type, according to the classification by Adachi-Williams-Nakagawa (Group IIIB1 type by Stewart, 1964).