What is an aortic dissection?

Murray H. Kwon, MD
Cardiology (Cardiovascular Disease)
An aortic dissection is where a tear creates a separation of the layers of the aorta. The aorta is normally a single-channel tube carrying blood to the body. When a dissection occurs, this single channel can become two or more. These channels are often weakened, thus leading to risk of growth of what are called aneurysms. They can potentially block blood flow to important parts of the body such as the brain, the kidney, the liver and the extremities. Aneurysms also represent a rupture risk of the aorta.
An aortic dissection is a tear in the wall of the aorta (the large blood vessel that carries blood from the heart) to the body, causing the inner and middle layers of the aorta to separate (dissect). In type A dissection, the tear begins where the aorta exits the heart (ascending aorta) and extends from the upper to lower sections of the aorta. Although type A dissection is rare, it is the most common type of aortic dissection and occurs mainly in men aged 50 to 65 with high blood pressure, hardening of the arteries, or any other abnormality of the aorta.
An aortic dissection occurs when a tear in the wall of the aorta causes blood to flow between the layers of the wall of the aorta. This rip often forces the layers of the aorta apart.

An aortic dissection is classified as Type A or Type B, depending on where it begins and ends. Type A begins in the first (ascending) part of the aorta, and Type B begins in the descending part of the aorta.
Aortic dissections are tears in the inner lining of the aorta that allow blood to flow through the walls of the aorta rather than remaining in the central channel (lumen). Type A dissections (beginning in the ascending aorta) require emergency surgery, while type B dissections (located under the collarbone) may be treated medically or surgically, depending on the severity of the complications.

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. 

Emily A. Farkas, MD
Thoracic Surgery (Cardiothoracic Vascular)

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. 

Tears occurring in other locations may not require surgery.  Your doctor makes a recommendation for surgery based on how the branches of the aorta are affected by the dissection and the location of the original tear.
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Aortic dissection means there is a dangerous tear in the wall of the aorta, the major artery that carries blood from your heart to the rest of your body. Watch as Dr. Oz explains more about aortic dissection and why it occurs.

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.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.