A thoracic aneurysm is an enlarged, or ballooned, area in the thoracic (chest) region of the aorta, the main blood vessel that carries blood away from the heart.
Aneurysms are a potentially serious health condition because they can burst or rupture, causing internal bleeding and, if untreated, death.
The risk for rupture increases with the size of the aneurysm. In general, thoracic aortic aneurysms larger than 6 cm (2.3 inches) in diameter should be considered for treatment. In certain individuals (women and people with Marfan's syndrome, for example), this size threshold for intervention may be decreased.
A thoracic aneurysm is an enlargement of a weak area in the part of the aorta located in the chest. While the normal diameter of the aorta is about an inch or smaller, an aneurysm can grow to be more than 3 inches in diameter. Aneurysms are a potentially serious health condition because they can burst or rupture. Larger aneurysms are more likely to rupture than smaller ones and can cause fatal internal bleeding unless treated very quickly by an experienced emergency medical team.
WHAT ARE THE SYMPTOMS?
Many people with thoracic aneurysms experience no symptoms. Symptoms, which depend on the aneurysm's location and the size of the aneurysm, may include:
Pain in the jaw, neck, and upper back;
Chest or back pain; and
Coughing, hoarseness, and difficulty breathing.
If the aneurysm is large it may affect other organs and nerves. If it affects the heart, a large aneurysm may lead to congestive heart failure.
CAUSES AND RISK FACTORS
The most common causes of thoracic aneurysms are atherosclerosis, or hardening of the arteries, and other degenerative diseases of the aorta.
The same risk factors that contribute to atherosclerosis, such as smoking, hypertension, and poor diet, may also contribute to risk of aneurysms. Other risk factors include:
Connective tissue disease, such as Marfan's syndrome;
Unusual infections, such as syphilis and tuberculosis;
Trauma, such as a blow to the chest; and
Separation of the layers of the aorta wall, called acute aortic dissection.
People at high risk for thoracic aneurysms include men older than 60 years and relatives of patients with aneurysms.
To determine whether or not a patient has a thoracic aneurysm, the physician may order one of the following tests:
Computed Tomography (CT) scans; or
Magnetic Resonance Imaging (MRI).
The decision to treat thoracic aneurysm is based on the risk of rupture.
Aneurysms that are smaller than 5 cm (about 1.5 inches) in diameter and do not cause symptoms may be monitored regularly (approximately every 6 months) using an ultrasound or CT scan, a practice called watchful waiting. People with small aneurysms and high blood pressure may be given medication to lower their blood pressure, which may reduce the risk of the aneurysm growing or rupturing. However, patients with small, asymptomatic thoracic aneurysms and Marfan's syndrome are often treated sooner than people who do not have Marfan's syndrome.
Surgical repair may be recommended for patients whose thoracic aneurysms cause symptoms or are larger than 6 centimeters (2.3 inches) in diameter. Surgical options are:
Open aneurysm repair, which involves opening the chest cavity and replacing the weakened area of the aorta with a fabric tube; and
Endovascular stent graft repair, in which a small synthetic tube is placed in the aorta using a catheter (thin, flexible tube) that is inserted through a small incision in an artery in the groin.