What is an aortic dissection?

The aorta is the largest blood vessel of the body, beginning at the heart, arching toward the back within the chest, and continuing down adjacent to the spine, where it divides to supply each leg. An aortic dissection is a serious condition in which the wall of the aorta tears, splitting in two to create two channels rather than one.  This is life-threatening, since the tear can cause the aorta to rupture, or it can disrupt flow to branches of the aorta that supply vital organs.  The tear can occur anywhere, but it most commonly occurs either in the first part of the aorta near the heart (the ascending aorta) or in the part of the aorta in the back of the chest (the descending aorta).  A dissection of the ascending aorta, near the heart, is a situation that requires emergency surgery to prevent rupture into the sac (the pericardium) around the heart and to prevent blockage of the coronary arteries.  A dissection of the descending aorta, in the back of the chest, can often be treated without surgery. Atherosclerosis (hardening of the arteries), uncontrolled high blood pressure, aneursyms, and certain inherited disorders which weaken the aorta may increase someone's risk of an aortic dissection.  The main symptom of an aortic dissection is severe chest or back pain, usually of sudden onset.  Any person with such symptoms should seek medical attention immediately. 

An aortic dissection is an internal split or tear in the wall of the aorta.  The aorta is a major blood vessel that exits the heart to travel throughout the entire body.  Like a run in a woman’s stocking, this tear will often travel a long distance from the place where it originates in the aorta.

As the tear moves throughout the body it can affect the vessels branching  off the aorta to provide blood flow to different areas.  In the most severe cases, this could mean that the brain, heart, spinal cord, arms, legs, or major organs may have their necessary blood flow lessened or stopped entirely.  In this situation, surgery is required to restore normal blood flow.  Another scenario requiring surgery is when the tear occurs in the aorta closest to the heart. 

An aortic dissection is a split or tear along the inner layer of the aorta's wall. Dissections occur more frequently in regions of the aorta where pressure on the artery wall from blood flow is high, such as its first arching segment above the heart. When the aortic wall tears, blood fills the pocket between the inner and outer layers, often increasing the length of the tear. As the blood-filled space between the layers expands, it can weaken the aortic wall resulting in an aneurysm formation or the flap of the tear can block off critical blood vessels going to the bowels, kidney, or legs.

An aortic dissection is a dangerous condition in which a tear develops in the inner layer of the aorta, the large blood vessel branching off the heart. When an aortic dissection is detected early and treated quickly, your chance of survival greatly improves.

There are two types of aortic dissections depending on where the tear occurs:

1. Type A. This is the more common type of aortic dissection. It involves a tear in the ascending portion of the aorta just where it exits the heart or a tear extending from the ascending portion down to the descending portion of the aorta, which may extend into the abdomen.
2. Type B. This type involves a tear in the descending aorta only, which also may extend into the abdomen.

Aortic dissection occurs in a weakened area of the aortic wall. Risk factors may include:

• Chronic high blood pressure
• Inherited conditions associated with a weakened and enlarged aorta, such as Marfan syndrome
• Traumatic injury to the chest area

Some aortic dissection patients may be candidates for less invasive procedures, although some may need surgical treatment.

Symptoms of aortic dissection are similar to those of a heart attack. They include: :

• Sudden severe chest or upper back pain, or abdominal pain, often described as a tearing, ripping or shearing sensation, that radiates down the back.
• Loss of consciousness (fainting) : .
• Shortness of breath.
• Weakness.