ABSTRACT
A 72-year-old man was admitted with an abnormal shadow on chest X-ray. Chest CT and aortography showed double saccular aneurysms at the aortic arch and the descending thoracic aorta. Three-dimensional CT was useful to detect the association between the arch aneurysm and neck vessels. Graft replacement, from the distal arch to the descending thoracic aorta, was performed by the lateral approach with hypothermic arrest and open proximal method. The aorta had severe atherosclerotic changes and the intima was absent at the orifices of the aneurysms. Pathological examination showed the aneurysmal wall to be composed of fibrous tissue without medial components. These macroscopic and pathological findings of aneurysms corresponded with double pseudo-aneurysms originating from the penetrating atherosclerotic ulcer.