Thoracic aortic aneurysmDefinition:
An aneurysm is an abnormal widening or ballooning of a portion of an artery due to weakness in the wall of the blood vessel.
A thoracic aortic aneurysm occurs in the part of the body's largest artery (the aorta) that passes through the chest.
See also: Aneurysm
Aortic aneurysm - thoracic; Syphilitic aneurysm; Aneurysm - thoracic aortic
Causes, incidence, and risk factors:
The most common cause of a thoracic aortic aneurysm is hardening of the arteries (atherosclerosis ). This condition is more common in people with high cholesterol, long-term high blood pressure, or who smoke.
Other risk factors for a thoracic aneurysm include:
- Connective tissue disorders such as Marfan syndrome
- Inflammation of the aorta
- Trauma such as falls or motor vehicle accidents
Aneurysms develop slowly over many years. Most patients have no symptoms until the aneurysm begins to leak or expand. Chest or back pain may mean sudden widening or leakage of the aneurysm.
Symptoms often begin suddenly when:
- The aneurysm grows quickly
- The aneurysm tears open (called a rupture)
- Blood leaks along the wall of the aorta (aortic dissection)
If the aneurysm presses on nearby structures, the following symptoms may occur:
- Swallowing problems
- High-pitched breathing (stridor)
- Swelling in the neck
Other symptoms may include:
- Chest or back pain
- Clammy skin
- Nausea and vomiting
- Rapid heart rate
- Low blood pressure
Signs and tests:
The physical examination is often normal unless a rupture or leak has occurred.
Most thoracic aortic aneurysms are detected by tests performed for other reasons, usually a chest x-ray, echocardiogram, or a chest CT scan . A chest CT scan shows the size of the aorta and the exact location of the aneurysm.
An aortogram (a special set of x-ray images made when dye is injected into the aorta) can identify the aneurysm and any branches of the aorta that may be involved.
The treatment depends on the location of the aneurysm. The aorta is made of three parts:
- The first part moves upwards towards the head. It is called the ascending aorta.
- The middle part is curved. It is called the aortic arch.
- The last part moves downwards, toward the feet. It is called the descending aorta.
For patients with aneurysms of the ascending aorta or aortic arch:
- Surgery to replace the aorta is recommended if an aneurysm is larger than 5 - 6 centimeters. The aorta is replaced with a plastic or fabric graft. This is major surgery that requires a heart-lung machine.
For patients with aneurysms of the descending thoracic aorta:
- Majory surgery is done to replace the aorta with a fabric graft if the aneurysm is larger than 6 centimeters.
- Endovascular stenting is a less invasive option. A stent is a tiny metal or plastic tube that is used to hold an artery open. Stents can be placed into the body without cutting the chest. Not all patients with descending thoracic aneurysms are candidates for stenting, however.
See also: Aortic aneurysm repair - endovascular
The long-term prognosis for patients with thoracic aortic aneurysm is determined by other medical problems such as heart disease and diabetes, which may have caused or contributed to the condition.
Serious complications after aortic surgery can include:
- Graft infection
- Heart attack
- Irregular heartbeat
- Kidney damage
Death soon after the operation occurs in 5 - 10% of patients.
Complications after aneurysm stenting include damage to the leg, which may require another operation.
Calling your health care provider:
Tell your doctor if you have:
- A family history of connective tissue disorders
- Chest or back discomfort
To prevent atherosclerosis:
- Control your blood pressure and blood lipid levels.
- Do not smoke.
- Exercise regularly.
Safi HJ, Estrera AL, Miller CC 3rd, Azizzadeh A, Porat EE. Thoracic vasculature with emphasis on the thoracic aorta. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2008:chap 63.