An aneurysm is a full thicknes weakening of the aortic wall. A partial thickness weakening of the aortic wall is a pseudoaneurysm. A tear in the intima and separation of th media along a trajectory of the aorta is a dissection.
Most aneurysms are of an atherosclerotic etiology.
These may be found along the ascending, transverse or descending aorta. Repair of the aortic arch requires total hypothermic circulatory arrest. The major problem with ascending aortic aneurysm repair is the need to bypass the coronary arteries if they are also involved. The problem with repair of the the descending aortic aneurysms is the frequent distal embolization of atherosclerotic debris to the lower extremities or mesenteric arteries with mesenteric ischemia and necrosis. Type 1 Intimal tear in the ascending aorta and dissection anywhere along the aorta.