Thoracic aortic aneurysm

Thoracic aortic aneurysm

Definition:
A thoracic aortic aneurysm is a weakened and bulging area in the upper part of the aorta, the major blood vessel that feeds blood to the body. The aorta, about the thickness of a garden hose, runs from your heart through the center of your chest and abdomen. Because the aorta is the body's main supplier of blood, a ruptured thoracic aortic aneurysm can cause life-threatening bleeding. Although you may never have symptoms, finding out you have a thoracic aortic aneurysm can be frightening.

Most small and slow-growing thoracic aortic aneurysms don't rupture, but large, fast-growing aneurysms may. Depending on the size and rate at which the thoracic aortic aneurysm is growing, treatment may vary from watchful waiting to emergency surgery. Once a thoracic aortic aneurysm is found, doctors will closely monitor it so that surgery can be planned if it's necessary. Emergency surgery for a ruptured thoracic aortic aneurysm can be risky.

Symptoms:
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 many expand over time. Some aortic aneurysms enlarge slowly, increasing less than half an inch (1.2 centimeters) a year. Others expand at a faster rate, which increases the risk of rupture. How quickly an aortic aneurysm may grow is difficult to predict.
As an aortic aneurysm grows, some people may notice:

• Tenderness or pain in the abdomen or chest
• Back pain

Aneurysms can develop anywhere along the aorta, which runs from your heart through your abdomen. When they occur in the upper part of the aorta, they are called thoracic aortic aneurysms. More commonly, aneurysms form in the lower part of your aorta and are called abdominal aortic aneurysms. Rarely, an aneurysm can 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
You should see your doctor if you have symptoms of a thoracic aortic aneurysm.
If you have a family history of aortic aneurysm, Marfan syndrome or other connective tissue disease, or bicuspid aortic valve, your doctor may recommend regular ultrasound exams to screen for aortic aneurysm.


Causes:
The exact causes of thoracic aortic aneurysms are unknown, but factors that can contribute to an aneurysm's development include:

• Marfan syndrome. 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. Those with Marfan syndrome may have a weakness in the aortic wall that makes them more susceptible to aneurysm. People with Marfan syndrome often have distinct physical traits, including tall stature, very long arms, a deformed breastbone and eye problems.
• Other connective tissue diseases. Besides Marfan syndrome, other connective tissue diseases, such as Ehlers-Danlos syndrome, can contribute to a thoracic aortic aneurysm. Ehlers-Danlos syndrome causes your skin, joints and connective tissue to be fragile and makes your skin stretch easily.
• Problems with your heart's valves. Sometimes, people who have problems with their aortic valve, the valve that blood flows through as it leaves your heart, have an increased risk of thoracic aortic aneurysm. This is especially true for people who have a bicuspid aortic valve, meaning their aortic valve has only two leaflets instead of three.
• Previous injury to the aorta. You're more likely to have a thoracic aortic aneurysm if you've had previous problems with your aorta, such as a tear in the wall of the aorta (aortic dissection).
• Traumatic injury. Some people who are injured in falls or motor vehicle crashes develop thoracic aortic aneurysms.

An aortic aneurysm is different from a condition called aortic dissection. Aortic dissection often occurs in the same place many aneurysms occur. 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). Aortic dissection is a life-threatening emergency.

Complications:
Tears in the wall of the aorta (dissection) 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 aortic aneurysm has burst include:

• Sudden, intense and persistent abdominal, chest or back pain
• Pain that radiates to your back or legs
• Sweatiness
• Clamminess
• Dizziness
• Low blood pressure
• Fast pulse
• Loss of consciousness
• Shortness of breath
• Weakness or paralysis of one side of the body, difficulty speaking or other signs of 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 and blocks a blood vessel elsewhere in your body, it can cause pain or block the blood flow to the brain, legs, toes or abdominal organs.


Treatments and drugs:
The goal of treatment is to prevent your aneurysm from rupturing. Generally, your treatment options are medical monitoring or surgery. Your decision depends on the size of the aortic aneurysm and how fast it's growing.

Medical monitoring
If your thoracic aortic aneurysm is small, your doctor may recommend medical monitoring, which includes regular appointments to make sure your aneurysm isn't growing, and management of other medical conditions that could worsen your aneurysm.

It's likely your doctor will order regular imaging tests to check on the size of your aneurysm. Expect to have an echocardiogram at least six months after your aneurysm is diagnosed and regular exams and imaging tests after that.

If you have high blood pressure or blockages in your arteries, it's likely that your doctor will prescribe medications to lower your blood pressure and reduce your risk of complications from your aneurysm. These medications could include:

• Beta blockers. Beta blockers lower your blood pressure by slowing your heart rate. Examples of beta blockers include metoprolol (Lopressor, Toprol-XL), atenolol (Tenormin) and bisoprolol (Zebeta).
• Angiotensin II receptor blockers. Your doctor may also prescribe these medications if beta blockers aren't enough to control your blood pressure. These medications are recommended for people who have Marfan syndrome, even if they don't have high blood pressure. Examples of angiotensin II receptor blockers include losartan (Cozaar), valsartan (Diovan) and olmesartan (Benicar).
• Statins. These medications can help lower your cholesterol, which can help reduce blockages in your arteries and reduce your risk of aneurysm complications. Examples of statins include atorvastatin (Lipitor), lovastatin (Mevacor), simvastatin (Zocor) and others.

If you smoke or chew tobacco, it's important that you quit. Using tobacco can worsen your aneurysm.

Surgery to prevent rupture
If you have a thoracic aortic aneurysm, surgery is generally recommended if your aneurysm is 2.2 inches (5.6cm) and larger. If you have Marfan syndrome, another connective tissue disease or a family history of aortic dissection, your doctor may recommend surgery for smaller aneurysms as well.
Depending on your condition and the location of your thoracic aortic aneurysm, your doctor may recommend:

• Open-chest surgery. Open-chest surgery to repair a thoracic aortic aneurysm involves removing the damaged section of the aorta and replacing it with a synthetic tube (graft), which is sewn into place. This procedure requires open-abdominal or open-chest surgery, and it will take you several months to fully recover.
• Endovascular surgery. Doctors attach a synthetic graft to the end of a thin tube (catheter) that's inserted through an artery in your leg and threaded up into your aorta. The graft — a woven tube covered by a metal mesh support — is placed at the site of the aneurysm and fastened in place with small hooks or pins. The graft reinforces the weakened section of the aorta to prevent rupture of the aneurysm.
• Other heart surgeries. If another condition is contributing to your aneurysm's development, such as a problem with your heart's valves, your doctor may recommend additional surgeries to repair or replace the damaged valves to stop your aneurysm from worsening.

Emergency surgery
Although it's possible to repair a ruptured aortic aneurysm with emergency surgery, the risk is much higher and there is less chance of survival. Many people who have a ruptured aortic aneurysm die before they reach the hospital.