The aorta is the largest blood vessel in the body. It delivers oxygenated blood from the heart to the rest of the body. An aortic aneurysm is a swollen, weakened area in the wall of the aorta. Over time, the blood vessel balloons and there is a risk of bursting (rupture) or separation (dissection). This can cause life-threatening bleeding and potentially death. You can find more information below.
What is a thoracic aortic aneurysm?
A thoracic aortic aneurysm is a weak area in the main blood vessel (the aorta) that supplies blood to the body. When the aorta is weak, blood being pushed against the vessel wall can cause the vessel to swell like a balloon (aneurysm). A thoracic aortic aneurysm is also called a thoracic aneurysm, and aortic dissection can occur due to an aneurysm. Dissection is a tear in the aortic wall that can cause life-threatening bleeding or sudden death. Large, fast-growing aneurysms are more likely to rupture, while small, slow-growing aneurysms are less likely to rupture.
Depending on the cause, size, and growth rate of the thoracic aortic aneurysm, treatment can range from watchful waiting to emergency surgery. Ideally, surgery can be scheduled if needed.
What causes a thoracic aortic aneurysm?
Factors that can contribute to the development of an aneurysm include:
- Hardening of the arteries (atherosclerosis): As plaque builds up on the artery walls, they become less flexible and the added pressure can cause them to weaken and swell. High blood pressure and high cholesterol are risk factors for hardening of the arteries. It is also more common in older people.
- Genetic conditions: Aortic aneurysms in young people often have a genetic cause. People born with Marfan syndrome , a genetic condition that affects the connective tissue in the body , are particularly at risk for a thoracic aortic aneurysm, as they may show weakness in the aortic wall. Marfan syndrome often causes different physical characteristics such as being tall, very long arms, a deformed breastbone, and eye problems. Other family-related disorders can cause aortic aneurysms, including Ehlers-Danlos syndrome , Loeys-Dietz syndrome, and Turner syndrome .
- 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: People who sometimes have problems with the valve through which blood flows as it exits the heart have an increased risk of thoracic aortic aneurysms.
- Untreated infection: Although rare, it is a risk factor if there is an untreated infection such as syphilis or salmonella.
- Traumatic injury: Rarely, some people injured in falls or motor vehicle accidents may also develop this disease.
In aortic dissection, a tear occurs in the aortic wall. This causes bleeding into the aortic wall, along the aorta, and in some cases completely outside the aorta.
Aortic dissection is a potentially life-threatening emergency depending on where in the aorta it occurs. It is important to treat an aortic aneurysm to prevent dissection. If dissection does occur, people can still be treated with surgery, but they have a higher risk of complications.
Who is at risk?
Thoracic aortic aneurysm risk factors include:
- Age: Thoracic aortic aneurysms are most common in people 65 years and older.
- Tobacco use: Tobacco use is a strong risk factor for the development of aortic aneurysm.
- High blood pressure: Increased blood pressure damages blood vessels throughout the body, increasing the risk of developing an aneurysm.
- Plaque buildup in arteries: The buildup of fat and other substances that can damage the lining of a blood vessel increases the risk of an aneurysm. This is a more common risk in the elderly.
- Family health history: People with a family history of aortic aneurysms are at greater risk. It is the primary risk factor in young people.
- Marfan syndrome and related conditions: If the patient has a related condition such as Marfan syndrome, Loeys-Dietz syndrome, or Ehlers-Danlos syndrome, the risk of thoracic aortic aneurysms and aortic or other blood vessel dissection or rupture is significantly higher.
- Bicuspid aortic valve: About half of those with two aortic valves instead of three may develop an aortic aneurysm.
What are the symptoms of a thoracic aortic aneurysm?
Thoracic aortic aneurysms usually progress slowly and without symptoms, making them difficult to detect. Some aneurysms never rupture. Many start small and stay small, but some expand over time. It is difficult to predict how fast an aortic aneurysm can grow.
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 originates from the heart and runs through the chest and abdomen. When they occur in the chest, it is called a thoracic aortic aneurysm. Aneurysms can occur anywhere in the thoracic aorta, close to 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 the aorta (abdominal aortic aneurysms). An aneurysm can also occur between the upper and lower parts of the aorta. This type of aneurysm is called a thoracoabdominal aneurysm .
When should you see a doctor?
Most people with an aortic aneurysm do not experience symptoms unless the rupture has occurred. A dissection or rupture is a medical emergency.
If an aneurysm or one or more layers of the artery wall ruptures, you may feel:
- Sharp, sudden pain radiating downward in the upper back
- pain in the chest, jaw, neck, or arms
- difficulty breathing
If there is a family history of aortic aneurysm, Marfan syndrome or another connective tissue disease or bicuspid aortic valve, the doctor may recommend regular ultrasound or radiology tests, such as computed tomography scans or magnetic resonance imaging exams, to screen for aortic aneurysms.
How is a thoracic aortic aneurysm diagnosed?
Thoracic aortic aneurysms are often found during routine medical tests such as chest X-ray , computed tomography. The doctor will also ask about symptoms and a family history of aneurysm or sudden death.
If he thinks he has an aortic aneurysm, imaging tests can confirm this. Thoracic aortic aneurysm tests include:
- Echocardiogram: An echocardiogram uses sound waves to capture real-time images of the heart and ascending aorta.
- Computed tomography: Computed tomography uses X-rays to create cross-sectional images of the body, including the aorta.
- Magnetic resonance imaging: A magnetic resonance imaging uses a magnetic field and radio waves to make pictures of the body.
Screening for thoracic aortic aneurysms
Conditions that cause thoracic aortic aneurysms can run in families genetically. Your doctor may recommend screening if a first-degree relative, such as a parent, sibling, son, or daughter, has Marfan syndrome or another condition that can cause a thoracic aortic aneurysm.
Tests used to screen for thoracic aortic aneurysms may include:
- Echocardiogram: If an echocardiogram shows an enlarged aorta or aneurysm, another imaging test will likely be needed within 6 or 12 months to make sure it’s not enlarged.
- Genetic testing: If there is a family history of aneurysm or another suspected genetic condition that increases the risk of thoracic aortic aneurysm, genetic testing may be considered. You may also want to consider genetic counseling before starting a family.
How is a thoracic aortic aneurysm treated?
The goal of treatment is to prevent the aneurysm from growing and to treat it before its dissection or rupture. Depending on the size and growth rate of the thoracic aortic aneurysm, treatment can range from watchful waiting to surgery.
If the thoracic aortic aneurysm is small, the doctor may recommend imaging tests to monitor the aneurysm, along with medication and management of other medical conditions.
Usually, an echocardiogram, computed tomography, or magnetic resonance angiography scan is performed at least six months after the aneurysm is diagnosed and at regular follow-up exams. How often these tests are done depends on the cause of the aneurysm, its size, and how fast it is growing.
If you have high blood pressure or blockages in the arteries, the doctor will likely prescribe medications to lower blood pressure and cholesterol.
These drugs may include:
- Beta blockers: Beta blockers lower blood pressure by slowing your heart rate. For people with Marfan syndrome, beta-blockers can reduce rapid enlargement of the aorta. Examples of beta blockers include metoprolol, atenolol and bisoprolol.
- Angiotensin 2 receptor blockers: If beta blockers are not sufficient to control blood pressure or if the patient cannot use beta blockers, the doctor may also prescribe these drugs. These medications are usually recommended for people with Marfan syndrome, even if they do not have high blood pressure. Examples of angiotensin 2 receptor blockers include losartan, valsartan, and olmesartan.
- Statins: These drugs can help lower cholesterol by helping to reduce blockages in the arteries and reduce the risk of aneurysm complications. Examples of statins include atorvastatin, lovastatin, simvastatin, and others.
Remember, your doctor will decide which medicine to take and how.
If the patient smokes or chews tobacco, it is very important to quit. Using tobacco can worsen an aneurysm.
Surgery is usually recommended for thoracic aortic aneurysms 1.9 to 2.4 inches (about 5 to 6 centimeters) and larger. If the patient has Marfan syndrome, another connective tissue disease, bicuspid aortic valve, or a family history of aortic dissection, surgery for smaller aneurysms may be recommended because of the higher risk of aortic dissection.
Most people with a thoracic aortic aneurysm will have open chest surgery, but in certain situations, the doctor may also decide on a less invasive repair called endovascular surgery.
The type of surgery performed depends on the condition and the location of the thoracic aortic aneurysm.
- Open thoracic surgery: Open thoracic surgery to repair a thoracic aortic aneurysm usually involves removing the damaged portion of the aorta and replacing it with a synthetic tube (graft) that is stitched in place. If the patient has Marfan syndrome or other related conditions, they may have aortic root replacement. The surgeon removes part of the aorta and sometimes the aortic valve and replaces part of the aorta with a graft. The aortic valve can be replaced with a mechanical or biological valve. If the valve is not removed, the surgical valve is called a protective aortic root repair.
- Endovascular surgery: Doctors add a synthetic graft to the end of a thin tube inserted through an artery in the leg and threaded into the aorta. The graft – a woven tube covered with a metal mesh backing – is inserted into the aneurysm site. Small hooks or pins hold the graft in place. The graft strengthens the weakened section of the aorta to prevent rupture of the aneurysm. Recovery time with this procedure is usually faster than with open chest surgery, but endovascular surgery cannot be done for everyone. Regular follow-up imaging scans are required after endovascular surgery to ensure that the graft is not leaking.
- Emergency surgery: While it is possible to repair a ruptured aortic aneurysm with emergency surgery, the risk is much higher and there is a greater chance of complications. For this reason, physicians prefer to identify, treat, and monitor thoracic aortic aneurysms before they rupture, with lifelong control and appropriate conservative surgery.