Three anomalous cases were encountered of the right subclavian artery as the last branch of the aortic arch during dissection practice at Nippon Medical School from 1976 to 1987. One of these cases dissected in 1976 was reported in 1980.
The present report describes the remaining two cases found in 1985 (an 81-year-old male) and 1987 (a 53-year-old male). These two cases belonged to type G according to Adachi's classification.
The aortic arch gave off the right common carotid artery as the first branch, the left common carotid artery as the second branch, the left subclavian artery as the third branch and the right subclavian artery as the last branch.
The right subclavian artery originated from the posterior wall of the aortic arch, a little distal to the origin of the left subclavian artery, at the level of the third thoracic vertebra. This artery ran between the spinal column and esophagus toward an area to the right of the first thoracic vertebra.
The vertebral artery arose from the subclavian artery in each side as the first branch, and penetrated into the 6th transverse foramen of the cervical vertebra.
The right recurrent nerve was absent but the right inferior laryngeal nerve arose directly from the right vagus nerve.
The cervical sympathetic trunk was normal and represented a normal subclavian loop.
The thoracic duct was normal and opened into the left venosus angle.
