The aorta is the body's largest artery, carrying oxygen-rich blood from the heart. When the heart's left ventricle contracts, the aortic valve opens and blood flows into the aorta. The aorta and its branches deliver vital nutrients to every part of the body, including the heart itself.
When the aorta is healthy, its elastic walls expand and contract with the ebb and flow of blood within it. However, when the aorta is diseased the area of weak, abnormal tissue bulges or balloons out. The stress of high-pressure blood flow on this abnormal tissue, which becomes weak and thin, puts this vital blood vessel at risk of tearing or rupture.
As the diseased section of aorta gradually weakens, the tissue bulges and eventually an aneurysm forms. State-of-the-art CT and MRI imaging, such as the 64- slice CTA pictured to the left showing bulging of the aortic root and ascending aorta, make it possible to view the entire aorta and find thoracic aortic disease before it results in a life-threatening emergency.
Thoracic aortic disease may be caused by several different conditions and may occur in both males and females of any age. When the underlying cause is genetically based, more than one family member may be affected.
TAD is serious because weak, fragile aortic tissue under high pressure may tear or rupture, causing life-threatening bleeding. Early detection can prevent emergencies that too often result in injury or loss of life.
Thoracic Aortic Disease (TAD) includes the following:
- Aneurysm - bulging or enlargement of a blood vessel due to weakness of the vessel wall
- Coarctation - narrowing of a blood vessel. In the aorta, the narrowing is in the section of the descending aorta near the arch.
- Dissection - a tearing of the inner lining of the aortic wall, allowing blood to enter and split the layers of the aortic wall. Blood may travel within the layers of the aorta, creating a "false" channel sometimes called a false lumen.
- Intramural hematoma - bleeding within the wall of the aorta, a variation of classic aortic dissection.
- Penetrating atherosclerotic ulcer - ulceration of atherosclerotic plaque penetrates into the aortic wall.
In some conditions, such as congenital bicuspid aortic valve, heart valves are also affected and are included in the overall evaluation of thoracic aortic disease.