Aberrant right subclavian artery is a common congenital anomaly of the aortic arch, with a reported prevalence of approximately 0.5%. However aneurysms of this aberrant vessel are very rare. A 71-year-old man was admitted with cerebral hemorrhage. Chest X-ray revealed an abnormal upper mediastinal shadow. Angiography, computed tomography (CT) scan, and magnetic resonance (MR) imaging revealed an aberrant origin of the right subclavian artery arising as the fourth branch of the aortic arch and crossing the mediastinum from left to right indenting the esophagus posteriorly. The origin of the right subclavian artery was aneurysmal (maximum diameter was 5cm), and this aneurysm did not compress the esophagus. The patient was treated by Dacron patch graft aortoplasty and right subclavian artery reconstruction with the aid of cardiopulmonary bypass and hypothermic selective cerebral perfusion. The postoperative course was uneventful and there were no major complications. The surgical technique is detailed as well as a review of all the cases in the literature.

Six cases without aortic reconstruction for 48 hours were encountered among 22 cases of Stanford type A acute aortic dissection from April, 1990 to July, 1996. They were one man and five women, with a mean age of 60.3 years old (from 52 to 82 years old). According to Hagiwara's definition, acute thrombotic aortic dissection (ATAD) was observed in four and acute opacified aortic dissection (AOAD) in two of six cases of Stanford type A acute aortic dissection without aortic reconstruction. One of the four ATAD cases was well-controlled by medical therapy, but the others could not be controlled and underwent aortic root reconstruction within 1 month. Two AOAD patients died due to rupture within 1 month. It is said in general that the patients with acute thrombotic aortic dissection can be treated medically, but we consider that they should be treated surgically because of the frequency of late rupture.