Ascending aortic false aneurysm formation associated with rupture of acute type a aortic dissection.

A 63-year-old man with ruptured acute type A aortic dissection was referred to our hospital. Computed tomography showed a false aneurysm arising from the false lumen located beside the ascending aorta. His hemodynamic status was stable inspite of the ruptured acute aortic dissection. We consider that the containment of the false aneurysm by thin mediastinal structures prevented worsening of his hemodynamic status, and this is extremely rare.