Thoracic Aortic Aneurysm
An aneurysm is an abnormal widening of a blood vessel, in this case the aorta - the main blood vessel that supplies blood to all parts of the body. The thoracic aorta is the part of the aorta that travels through the chest.
What is going on in the body?
A weakening of the wall of the aorta can cause it to widen or swell. The larger the aneurysm, the more pressure it puts on the wall in that area and the greater the risk of rupture. An artery that ruptures (bursts open) is an emergency that often causes death.
What are the causes and risks of the disease?
Causes of thoracic aortic aneurysm include:
- hardening and narrowing of the arteries, known as atherosclerosis
- hypertension (high blood pressure)
- genetic diseases that cause weakness of the tissues that make up the aorta
- late stage syphilis, a sexually transmitted disease
- other infections or inflammation of the aorta
- chest trauma, such as a crush injury
In many cases, the cause is not known.
What can be done to prevent the disease?
Many times nothing can be done to prevent a thoracic aortic aneurysm. Cases due to syphilis can be prevented with proper treatment early in the course of the disease. Reducing coronary risk factors can often prevent cases due to atherosclerosis. This includes not smoking and controlling high blood pressure, diabetes, and high cholesterol, if present.
How is the disease diagnosed?
A thoracic aortic aneurysm can sometimes be seen on a regular chest x-ray. Other special x-ray tests, such as a chest CT scan or magnetic resonance imaging (MRI), are used to detect and measure the size of the aneurysm.
Long Term Effects
What are the long-term effects of the disease?
Many people with a thoracic aortic aneurysm have no symptoms for many years. However, the long-term effects can be quite serious, and include:
- congestive heart failure
- heart attack
- blood clots
- sudden death
Death is usually due to sudden rupture of the aneurysm. The size and underlying cause of this condition primarily determine the risk of rupture.
What are the risks to others?
A thoracic aortic aneurysm is not contagious and poses no risk to others.
What are the treatments for the disease?
Small thoracic aortic aneurysms, especially in persons who cannot tolerate major surgery because of other health conditions, are treated with heart and blood pressure medications. These individuals are watched closely and sent for surgery only if needed.
Surgery is the treatment of choice if the aneurysm is bigger than 5 to 6 centimeters, or roughly 2 inches wide. Surgery involves replacing the abnormal part of the aorta with an artificial graft. In some cases, the aortic valve may also need to be repaired or replaced.
The decision to perform surgery partly depends on the underlying cause of the condition. The risks and benefits of surgery should be discussed with the surgeon. Treatment is tailored to the needs of each person.
An aneurysm rupture is usually fatal within a few minutes unless it occurs in the hospital where immediate access to repair surgery is available.
What are the side effects of the treatments?
All medications have possible side effects including allergic reactions. Specific side effects depend on the medications used.
Surgery is associated with a risk of bleeding, infections, and death. Paralysis, life-threatening blood clots, and allergic reactions to anesthesia are also possible.
What happens after treatment for the disease?
A person with a thoracic aortic aneurysm that is being treated only with medications needs regular office visits to follow the condition. Any new or worsening symptoms should be reported to the healthcare provider immediately.
If surgery is done, a period of recovery is required. Thoracic aneurysm repair is associated with many risks, but the benefit is preventing sudden death from a rupture. After recovery, the person will be closely observed for leakage from the artificial graft.
How is the disease monitored?
After surgery, a person will need to see the healthcare provider for regular visits. Someone who is treated only with medications will often have repeated special x-ray tests to watch for an increase in aneurysm size.
Merck Manual, 1999
Harrison's Principles of Internal Medicine, 1991
Current Medical Diagnosis and Treatment, 1996