Aortic Dissection
The aorta, the largest artery in the body, transports oxygen rich blood from the left ventricle of the heart to the rest of the body. As it emerges from the left ventricle of the heart, the aorta has the shape of a walking cane with an ascending part, an arch, and a descending part that travels through the chest and continues into the abdomen. From the aorta, branches to the head, arms, chest, abdomen, and legs supply the body with oxygen and nutrients.
What is an aortic dissection?
An aortic dissection is the splitting of the wall of the aorta resulting in the formation of a second channel through which blood may pass. Aortic dissections can begin as a defect in the inner layer (intima) of the vessel wall that forms a tear. The pressure of the blood in the aorta increases the size of the tear causing it to spread to the middle layer of the aorta, where the second channel forms. Dissections can also result from a rupture in one of the small vessels that travel through the outer layers of the wall of the aorta. The resulting hemorrhage causes a cleft to form that extends to its inner lining of the aorta, forming the second channel. Regardless of its method of formation, the deviation of blood into the second channel diverts blood from its intended pathways, and causes reduced blood flow to the body's organs. In addition, the splitting of the aortic wall of the weakens the aorta and makes it susceptible to aneurysm (ballooning of the vessel wall) and possible rupture.
What are the risk factors for aortic dissection?
Conditions such as atherosclerosis, malformations of the aorta or aortic valve, hypertension (high blood pressure), connective tissue diseases including Marfan's syndrome and Ehlers-Danlos syndrome, and certain congenital heart defects can increase the risk of aortic dissection.
How is aortic dissection diagnosed?
Patients with aortic dissection can experience intense "stabbing" pain in the chest, between the shoulder blades in the back, or in the neck. Diagnostic tests used to confirm a diagnosis of aortic dissection include:
- Chest x-ray
- Transthoracic Echocardiogram
- Transesophageal echocardiogram
- CT scan
- MRI
- Aortography (angiography of the aorta)
Treatment options for aortic dissection:
In most cases, an aortic dissection is a potentially fatal medical emergency that requires immediate treatment. Small dissections might be treated with drug therapy to reduce blood pressure, followed by careful monitoring. However, most cases of aortic dissection require surgical repair, which involves removal of the diseased section of the aorta, followed by its replacement with a graft.
