Thoracic Aortic Aneurysm
An aneurysm is a bulge in an artery, caused by a weakening of the blood vessel wall. A thoracic aortic aneurysm forms in the chest, within the body's largest artery, known as the aorta, typically caused by atherosclerosis, or hardening of the arteries. Atherosclerosis is a condition in which a gradual buildup of fats and cholesterol along the artery walls hardens into a substance called plaque. As the amount of plaque increases, it slowly narrows the diameter of the artery, often causing an aneurysm, and contributing to other cardiovascular disorders.
Risk Factors for a Thoracic Aortic Aneurysm
In addition to atherosclerosis, there are a number of risk factors for developing a thoracic aortic aneurysm; they include the following:
- Certain connective tissue disorders
- Family history of aneurysms
- High blood pressure
- Traumatic injury to the chest
Smoking also increases the risk for a thoracic aortic aneurysm.
Symptoms of a Thoracic Aortic Aneurysm
In the majority of patients, a thoracic aortic aneurysm develops gradually, over a long period of time. There are frequently no noticeable symptoms, unless the aneurysm expands rapidly, starts to leak, or ruptures. Because the aorta supplies much of the body's blood, an expanding, leaking or ruptured aneurysm is potentially deadly, and requires immediate medical intervention. It is much more common, however, for a thoracic aortic aneurysm to remain intact.
When patients do experience symptoms from a thoracic aortic aneurysm, they typically manifest as pain in the chest or upper back. In some people, the neck and throat are affected, resulting in difficulty swallowing, a hoarse voice, wheezing and swelling in the neck region. If the aneurysm has ruptured or is leaking, symptoms are generally much more pronounced, and may take the form of intense chest or back pain, nausea, rapid heart beat, sweatiness and loss of consciousness.
Diagnosis of a Thoracic Aortic Aneurysm
To determine the presence of a thoracic aortic aneurysm, several imaging tests, including X-rays, CT scans, MRI scans and echocardiograms, may be performed. In order to establish the location and extent of the aneurysm, a test called an aortogram may be necessary. During an aortogram, dye is injected into the aorta, which is then viewed on a specialized type of X-ray, providing a more detailed visualization of the aneurysm.
Treatment for a Thoracic Aortic Aneurysm
Treatment for a thoracic aortic aneurysm varies depending on many factors, including its size, location and severity, and the overall health of the patient. Small, asymptomatic aneurysms may be regularly monitored and treated conservatively with medication that lowers blood pressure and reduces the risk of a rupture. Beta blockers, angiotensin II receptor blockers, and statins are often prescribed to lower the risk of complications from a thoracic aortic aneurysm.
In other cases, particularly if the aneurysm is 5 to 6 centimeters in length, surgery may be necessary. An open procedure, which is performed under general anesthesia, involves an incision in the chest. The affected portion of the aorta is removed and a synthetic graft is attached to replace it, thereby repairing and strengthening the weakened blood-vessel wall. This is a major surgical procedure that may require a week's stay in the hospital, and several months of recovery.
Certain patients may be eligible for a minimally invasive treatment method as an alternative to open surgery. One commonly used procedure, known as endovascular stenting, involves placing a stent (a small metal tube) within the artery to help it remain open. The stent is placed using special instruments inserted through tiny incisions in the groin, and then directed through the blood vessels by a catheter to the aneurysm. Where possible, this less invasive method is preferable because healing is less difficult and recovery takes less time.