[Cardiac tamponade due to ruptured intramural hematoma of the ascending aorta: a case report].

A 72-year-old man with a history of hypertension for 20 years was admitted with symptoms of acute aortic dissection. Computed tomography showed a crescentic thickening of the ascending aortic wall, suggesting an intramural hematoma. Sixteen hours after admission, he underwent urgent repair of the ascending aorta because of cardiac tamponade. We inspected the inside of the aorta from the aortic valve to the arch. Subadventitial hematoma due to hemorrhage from the outer media was confirmed. Rupture of the vasa vasorum was thought to be an initiating mechanism. The affected aortic wall was simply resutured and was not replaced with a graft because the intima was intact and the media was not dissected and the aortic wall was considered to be tolerable to normal blood pressure. The patient continues to do well 18 months following operation. An intramural hematoma of the ascending aorta should be regarded as a precursor of imminent rupture or classic dissection.