[A report of surgical treatment for atherosclerotic aneurysm in the aortic arch associated with type III acute aortic dissection].

A 75-year-old man was admitted to our hospital because of severe chest pain. A chest CT scan demonstrated an atherosclerotic true aneurysm measuring 50 mm in diameter located just distal to the aortic arch as well as a DeBakey type III dissection. Although the patient received medical therapy, the size of the true aortic aneurysm increased to 71 mm and the false lumen of the descending aorta was also enlarged after three weeks. At 11 weeks after admission, the aortic arch and the proximal portion of the descending aorta were replaced with a 32 mm Hemashield graft using moderate hypothermic selective cerebral perfusion. The postoperative course was uneventful, and there were no neurological complications. Coexistence of atherosclerotic true aneurysm and acute aortic dissection appears to increase the risk of aortic rupture, early surgical treatment should be considered.