Thoracic Aortic Aneurysm
The aorta is the largest artery (blood vessel) in the body and carries oxygen-rich blood away from the heart to all parts of the body. The part of the aorta that runs through the chest is the thoracic aorta (also referred to as the descending aorta). Thoracic aortic aneurysms affect approximately 15,000 people in the U.S. each year and occur when there is a weakened area in the wall of the thoracic aorta resulting in an abnormal widening or ballooning.
The most common cause of a thoracic aortic aneurysm is atherosclerosis, or hardening of the arteries. This condition is more common in people with high cholesterol, long-term high blood pressure, or those who smoke. Other risk factors for a thoracic aneurysm include:
- High blood pressure
- High cholesterol
- Connective tissue disorders such as Marfan or Ehlers-Danlos syndrome
- Inflammation of the aorta
- Injury to the chest from motor vehicle accidents or falls
The best way to prevent the occurrence of an aneurysm is to prevent atherosclerosis. Patients can lower their risk of atherosclerosis by controlling blood pressure and blood lipid levels, not smoking, eating a healthy diet and exercising regularly.
Aneurysms develop slowly over many years. Most people have no symptoms until the aneurysm begins to leak or expand. As the aneurysm grows, some people may notice the following symptoms:
- Tenderness or pain in the chest or upper back
- Swallowing problems
- Nausea and vomiting
- Rapid heart rate
- Shortness of breath
Symptoms often begin suddenly when the aneurysm grows quickly, the aneurysm tears the aortic wall or blood leaks along the wall of the aorta. If the aneurysm presses on nearby structures, the following symptoms may occur:
- Swallowing problems
- High-pitched breathing (stridor)
- Swelling in the neck
A person with an aneurysm may often have a normal physical exam unless a rupture or leak has occurred. Most thoracic aortic aneurysms are detected on imaging tests performed for other reasons. These tests include chest x-ray, echocardiogram, or chest CT scan or MRI. A chest CT scan can show the size of the aorta and the exact location of the aneurysm. An aortogram is a special set of x-ray images made when dye is injected into the aorta. These images can identify the aneurysm and any branches of the aorta that may be involved.
The goal for treatment of aneurysms is to prevent rupture. There are two options for the treatment – medical monitoring and open/endovascular surgery. The recommended treatment option will depend on the size of the aneurysm, where it is located in the aorta, and how fast it is growing. For patients with a small thoracic aortic aneurysm, the recommended treatment may be medical monitoring which includes regular tests to make sure the aneurysm isn't growing, and management of other medical conditions that could worsen the aneurysm. Patients can expect to have a CT scan to monitor the aneurysm and those with high blood pressure or blockages in their arteries can expect their physician to prescribe medications to lower blood pressure and reduce cholesterol levels in an effort to reduce the risk of complications from the aneurysm. Medications may include:
- Beta blockers to lower blood pressure by slowing a patient's heart rate.
- Angiotensin II receptor blockers to control blood pressure if beta blockers aren't enough or if a patient can't take beta blockers.
- Statins to help lower cholesterol which can help reduce blockages in the arteries and reduce the risk of aneurysm complications.
Surgery is typically recommended for patients with a thoracic aortic aneurysm about 5.5cm (2 inches) and larger. Surgery may also be recommended for those with Marfan syndrome, another connective tissue disease, or a family history of aortic aneurysms. The following options may be recommended depending on the patient's condition and the location of the thoracic aortic aneurysm:
- Open chest surgery to repair the thoracic aortic aneurysm which involves removing the damaged section of the aorta and replacing it with a synthetic graft (tube), which is sewn into place. Patients can expect a month or more before full recovery.
- Endovascular surgery in which doctors covers the aneurysm with a stent graft that's inserted through an artery in your leg and threaded up into your aorta. The stent -graft — a fabric tube supported by a metal mesh — is placed at the site of the aneurysm from inside the artery. The graft reinforces the weakened section of the aorta to prevent rupture of the aneurysm. Patients can typically expect a faster recovery time after this procedure than with open surgery, but endovascular surgery is not an option for all patients. Regular follow-up scans are required after the procedure to ensure the graft is not leaking.
Some serious complications after aortic surgery may include bleeding, graft infection, heart attack, irregular heartbeat, kidney damage, paralysis and stroke.
For information about thoracic aortic aneurysm treatment at Tampa General Hospital’s Cardiovascular Center Aorta Program or to refer a patient, call (813) 394-5554 Monday through Friday, 8:00 a.m. - 4:30 p.m.
To transfer patients after business hours, call the TGH Transfer Center at 1-800-247-4472.