Aortic dissection is a serious condition in which there is a tear in the wall of the major artery carrying blood out of the heart (aorta). As the tear extends along the wall of the aorta, blood can flow in between the layers of the blood vessel wall (dissection). This can lead to aortic rupture or decreased blood flow (ischemia) to organs.
Aortic aneurysm - dissecting
When it leaves the heart, the aorta first moves up through the chest towards the head (the ascending aorta). It then bends or arches, and finally moves down through the chest and abdomen (the descending aorta).
Aortic dissection most often happens because of a tear or damage to the inner wall of the aorta. This very often occurs in the chest (thoracic) part of the artery, but it may also occur in the abdominal aorta.
When a tear occurs, it creates two channels:
One in which blood continues to travel
Another where blood stays still
If the channel with non-traveling blood gets bigger, it can push on other branches of the aorta. This can narrow the other branches and reduce blood flow through them.
An aortic dissection may also cause abnormal widening or ballooning of the aorta (aneurysm).
The exact cause is unknown, but more common risks include:
Deepak Sudheendra, MD, Assistant Professor of Interventional Radiology & Surgery, Hospital of the University of Pennsylvania, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.