What does having dissecting aortic aneurysm mean?

Tear of the aorta. The aorta is the largest blood vessel in the body running from the heart to the top of the pelvis. It has a smooth lining and a muscular wall. A dissection of the aorta is a tear of the lining of the aorta allowing blood to pass between the lining and the wall which can cause problems in blood flow and in some cases can be life-threatening. Acute aortic dissection typically produces sharp sever.
Torn lining of aorta. The largest blood vessel in the body normally has a lining consisting of three layers. If the inner layer tears away from the middle layer, blood may not flow properly into the arteries that serve the brain, the kidneys or other organs. Depending on the exact location of the dissection, this may be an emergent life-threatening condition requiring immediate surgery.