Aortic Dissection ---- A dissecting aortic aneurysm (aortic dissection) occurs when a tear in the intima allows blood to enter the media, creating a false lumen that can propagate along the aortic wall. --- Pathophysiology Initiated by intimal tear → blood dissects into media → separation of layers. The false lumen may re-enter the true lumen or rupture externally (fatal). Weakening of media due to hypertension, cystic medial degeneration, or connective tissue disease (e.g., Marfan, Ehlers–Danlo