Contributor: Gordon K. Klintworth
A dissecting aneurysm may form in any artery, but the majority involve the aorta. An intimal tear is present in 95% of cases and the dissections proceeds above and below the tear. In the carotid arteries and other large arteries it may follow the introduction of a needle or catheter into the artery. Seventy five percent of individuals with a dissecting aneurysm of the aorta have hypertension. Other systemic disorders that predispose to an aortic disseccting aneurysm include Ehlers-Danlos syndrome type VI. The dissecting aneurysm may result in a complete occlusion of the involved vessel and the resultant occlusovascular disease leads to ischemia of the area supplied by that artery. Infarction may result. The dissection commonly results in tear in the outer wall of the artery and an external rupture with hemorrhage. This is commonly fatal especially if the aorta is involved.