This Publication Is Searchable The Merck Manual of Diagnosis and Therapy Section 16. Cardiovascular Disorders Chapter 211. A tear in the aortic intima through which blood surges into the aortic wall, stripping the media from the adventitia.
Aortic dissection is highly lethal.
The advancing column of blood forms a false channel within the aorta, which usually extends distally and, less commonly, proximally from the initial intimal tear. Dissection occurs within the layers of the media and may rupture through the adventitia or back through the intima. The false channel may reenter the true aortic lumen at any point. The blood supply of any tributary artery of the aorta may be compromised, and the aortic valve may be rendered incompetent. Death often follows from rupture of the aorta, usually into the pericardial cavity or left pleural space.