[A case of the right aortic arch with the left subclavian artery as its last branch]

Abstract

A case of the right aortic arch with the left subclavian artery as its last branch was found in an 80-year-old Japanese female cadaver during the 1990 dissection for students. The main findings were as follows. The ascending aorta arose from the left ventricle and ran right and upward to the level of the intervertebral disc between the 2nd and 3rd thoracic vertebrae. It then curved right and backward to form the aortic arch. The aortic arch joined the thoracic aorta that descended along the right side of the vertebral column and crossed obliquely the vertebral column at the level of the 8th thoracic vertebra. Finally it entered the abdomen through the aortic hiatus behind the esophagus. Four branches were given off from the aortic arch in the following order from left to right: the left common carotid, the right common carotid, and the right subclavian and the left subclavian arteries. The left subclavian artery, which had an aortic diverticulum at the origin of the aortic arch, ran left and upward behind the esophagus. The ligamentum arteriosum connected the left pulmonary artery with the aortic diverticulum of the left subclavian artery. The left common carotid artery, which normally had no branches before entering the cranium, gave off an accessory esophageal branch about 20 mm distally from its origin. The right and left vertebral arteries entered the transverse foramen of the 6th cervical vertebra. The left recurrent laryngeal nerve hooked around from the left dorsal to the right ventral part of the ligamentum arteriosum.(ABSTRACT TRUNCATED AT 250 WORDS)