Thoracic aortic aneurysm
A thoracic aortic aneurysm is a weakened area in the upper part of the aorta — the major blood vessel that feeds blood to the body. Aneurysms can develop anywhere in the aorta.
A thoracic aortic aneurysm is a weakened area in the major blood vessel that feeds blood to the body (aorta). When the aorta is weak, blood pushing against the vessel wall can cause it to bulge like a balloon (aneurysm).
A thoracic aortic aneurysm is also called a thoracic aneurysm, and aortic dissection can occur because of an aneurysm. A dissection is a tear in the wall of the aorta that can cause life-threatening bleeding or sudden death. Large, fast-growing aneurysms also may rupture, but small and slow-growing aneurysms may never rupture.
Depending on the cause, size and growth rate of your thoracic aortic aneurysm, treatment may vary from watchful waiting to emergency surgery. Ideally, surgery can be planned if necessary.
Thoracic aortic aneurysms often grow slowly and usually without symptoms, making them difficult to detect. Some aneurysms will never rupture. Many start small and stay small, although some expand over time. How quickly an aortic aneurysm may grow is difficult to predict.
As a thoracic aortic aneurysm grows, some people may notice:
- Tenderness or pain in the chest
- Back pain
- Shortness of breath
Aortic aneurysms can develop anywhere along the aorta, which runs from your heart through your chest and abdomen. When they occur in the chest, they're called thoracic aortic aneurysms. Aneurysms can occur anywhere in the thoracic aorta, including near the heart, in the aortic arch and in the lower part of the thoracic aorta.
Thoracic aortic aneurysms are less common than aneurysms that form in the lower part of your aorta (abdominal aortic aneurysms). An aneurysm can also occur in between the upper and lower parts of your aorta. This type of aneurysm is called a thoracoabdominal aneurysm.
When to see a doctor
Most people with aortic aneurysms don't have symptoms unless a tear or rupture occurs. A dissection or rupture is a medical emergency. Call 911 or your local emergency number for immediate assistance.
If an aneurysm ruptures or one or more layers of the artery wall tears, you may feel:
- Sharp, sudden pain in the upper back that radiates downward
- Pain in your chest, jaw, neck or arms
- Difficulty breathing
If you have a family history of aortic aneurysm, Marfan syndrome or another connective tissue disease, or a bicuspid aortic valve, your doctor may recommend regular ultrasound or radiology testing such as CT scans or MRI exams to screen for aortic aneurysm.
Factors that can contribute to an aneurysm's development include:
- Hardening of the arteries (atherosclerosis). As plaque builds up on your artery walls, they become less flexible, and the additional pressure can cause them to weaken and bulge. High blood pressure and high cholesterol are risk factors for hardening of the arteries. This is more common in older people.
Genetic conditions. Aortic aneurysms in younger people often have a genetic cause. People who are born with Marfan syndrome, a genetic condition that affects the connective tissue in the body, are particularly at risk of a thoracic aortic aneurysm because they may have weakness in the aortic wall.
Marfan syndrome generally causes distinct physical traits, including tall stature, very long arms, a deformed breastbone and eye problems.
Other family-related disorders can cause an aortic aneurysm, including vascular Ehlers-Danlos, Loeys-Dietz and Turner syndromes. Vascular Ehlers-Danlos syndrome causes your skin, joints and connective tissue to be fragile and makes your skin stretch easily.
- Other medical conditions. Inflammatory conditions, such as giant cell arteritis and Takayasu arteritis, are associated with thoracic aortic aneurysms.
- Problems with your heart's aortic valve. Sometimes people who have problems with the valve that blood flows through as it leaves the heart (aortic valve) have an increased risk of thoracic aortic aneurysm. This is mainly true for people who were born with an aortic valve that has only two flaps instead of three (bicuspid aortic valve).
- Untreated infection. Though rare, it's possible to develop a thoracic aortic aneurysm if you've had an untreated infection, such as syphilis or salmonella.
- Traumatic injury. Rarely, some people who are injured in falls or motor vehicle crashes develop thoracic aortic aneurysms.
Aortic aneurysm and aortic dissection
An aortic aneurysm occurs when a weak spot in the wall of the aorta begins to bulge, as shown in the image on the left. An aneurysm can occur anywhere in the aorta. Having an aortic aneurysm increases the risk of a tear in the aortic lining (aortic dissection), as shown in the image on the right.
In aortic dissection, a tear occurs in the wall of the aorta. This causes bleeding into and along the aortic wall and, in some cases, completely outside the aorta (rupture).
An aortic dissection is a potential life-threatening emergency, depending on where in the aorta it occurs. It's important to treat an aortic aneurysm to try to prevent dissection. If dissection occurs, people can still be treated with surgery, but they will have a higher risk of complications.
Thoracic aortic aneurysm risk factors include:
- Age. Thoracic aortic aneurysms occur most often in people age 65 and older.
- Tobacco use. Tobacco use is a strong risk factor for the development of an aortic aneurysm.
- High blood pressure. Increased blood pressure damages the blood vessels in the body, raising your chances of developing an aneurysm.
- Buildup of plaques in your arteries. The buildup of fat and other substances that can damage the lining of a blood vessel increases your risk of an aneurysm. This is a more common risk in older people.
- Family history. People who have a family history of aortic aneurysm are at increased risk of having one. A family history means you may develop aneurysms at a younger age and you're at higher risk of rupture. This is a primary risk factor in younger people.
- Marfan syndrome and related conditions. If you have Marfan syndrome or a related condition, such as Loeys-Dietz syndrome or vascular Ehlers-Danlos syndrome, you have a significantly higher risk of a thoracic aortic aneurysm and aortic or other blood vessel dissection or rupture.
- Bicuspid aortic valve. Nearly half of those who have an aortic valve with two cusps instead of three may develop an aortic aneurysm.
Tears in the wall of the aorta and rupture of the aorta are the main complications of thoracic aortic aneurysm. A ruptured aortic aneurysm can lead to life-threatening internal bleeding. In general, the larger the aneurysm, the greater the risk of rupture.
Signs and symptoms that your thoracic aortic aneurysm has burst include:
- Sudden, intense and persistent chest or back pain
- Pain that radiates to your back
- Trouble breathing
- Low blood pressure
- Loss of consciousness
- Shortness of breath
- Trouble swallowing
- Weakness or paralysis of one side of the body, difficulty speaking, or other signs of a stroke
Blood clot risk
Another complication of aortic aneurysms is the risk of blood clots. Small blood clots can develop in the area of the aortic aneurysm. If a blood clot breaks loose from the inside wall of an aneurysm, it can block a blood vessel elsewhere in your body, possibly causing serious complications.