Abstract
We encountered a case of ruptured penetrating atherosclerotic ulcer (PAU) that previously had focal ulceration. A 82-year-old man was followed on a diagnosis of distal arch true aneurysm with a diameter of 4.5cm on CT examination. He was admitted with sudden onset of back pain, but he had experienced no previous symptom. CT scan showed a ruptured penetrating atherosclerotic ulcer, therefore we performed emergency replacement of the thoracic descending aorta. The postoperative course was good. CT scan showed the thoracic descending aorta had focal ulceration with a width of 11mm and depth of 7mm at 6 months, however the width was 11mm and the depth was 11mm 1 month before rupture of the PAU. This suggested progression of the focal ulceration caused the PAU rupture.
