Ascending Aortic Aneurysm

An ascending aortic aneurysm is a weak spot in the top part of your aorta, which is the main artery in your body. The aneurysm bulges outward, and may cause your blood vessel wall to tear or break open. It’s a life-threatening condition. About 60% of all aneurysms in the thoracic aorta (in your chest) affect the ascending aorta.


What is an ascending aortic aneurysm?

An ascending aortic aneurysm is a bulging area in the first part of the aorta, the main artery in your body. An aneurysm is a weak spot in a blood vessel wall. Aneurysms can tear or rupture (break open) and cause severe, life-threatening internal bleeding. These aneurysms are also called ascending thoracic aortic aneurysms (ATAAs) since they’re in your chest.

Risk factors for ascending aortic aneurysm

The following factors make you more likely to develop an ATAA:


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How common are ascending aortic aneurysms?

Approximately 60% of all thoracic aortic aneurysms affect the ascending aorta. Ascending aortic aneurysms affect about 10 out of 100,000 people each year.

Symptoms and Causes

What causes ascending aortic aneurysms?

ATAAs develop when a blood vessel wall becomes weak or damaged. Aging and heart disease can make the aorta less elastic. The force of blood against the weak area causes the blood vessel to bulge outward.

The following conditions can lead to aneurysms:

  • Aortitis, or inflammation of the aorta.
  • Atherosclerosis (plaque buildup inside your arteries).
  • Bicuspid aortic valve disease (two aortic valve flaps instead of the normal three).
  • Loeys–Dietz syndrome, a genetic disorder that can cause an enlarged aorta.
  • Marfan syndrome, a connective tissue disorder that can affect blood vessel walls.
  • Traumatic injuries can cause tears in the artery wall.
  • Turner syndrome, a genetic disorder that can cause cardiovascular problems.


What are the symptoms of an ascending thoracic aortic aneurysm?

Most people with ATAAs don’t experience any symptoms. But it’s important to talk to your healthcare provider right away if you have:

Diagnosis and Tests

How are ascending aortic aneurysms diagnosed?

Since ATAAs don’t usually cause symptoms, they can be difficult to diagnose. They’re often detected by chance during an exam for another health condition. If your healthcare provider discovers an aneurysm, they may use a variety of imaging tests to learn more about it:

  • Chest X-ray: This quick imaging exam can show an enlarged aorta, but a chest X-ray isn’t detailed enough to show smaller aneurysms.
  • Transthoracic echocardiogram (TTE): This test uses sound waves to show how blood flows through your heart. A TTE can also identify problems with your heart valves.
  • Chest CT scan: A chest CT scan uses X-rays to create 3D pictures of your chest. It’s detailed enough to show even small aneurysms and dissections in your aorta, particularly if contrast is administered through an IV during the scan.
  • MR angiography: A performs an MRI of the chest and heart. Angiography can assess how well your left ventricle and aortic valve are working.


Management and Treatment

How are ascending aortic aneurysms treated?

Treatment for an ATAA depends on its size, rate of growth and underlying cause. Aneurysms that are smaller than 5.5 centimeters don’t usually need surgery right away unless you have additional risk factors (such as family history, connective tissue disorder and bicuspid aortic valve). Your healthcare provider may recommend:

  • Medications to manage your blood pressure and reduce force against the artery wall.
  • Imaging exams about every six months to monitor the size of the aneurysm. Then every few years if the aneurysm isn’t growing quickly.
  • Lifestyle adjustments such as diet, exercise and not smoking. Talk to your healthcare provider about safe, low-impact physical activities that won’t put too much pressure on your arteries.

Aneurysms larger than 5.5 centimeters typically need surgery, but there are exceptions. For instance, people with Marfan syndrome, a bicuspid aortic valve or a family history of aneurysms may need surgery sooner. Studies suggest these conditions make it more likely an aneurysm will rupture at a smaller size. Your healthcare provider will make recommendations for surgery based on your individual needs.

How can surgery treat an ascending aortic aneurysm?

During aneurysm repair surgery, a surgeon makes an incision (cut) in your chest to access your aorta. They remove the aneurysm bulge by cutting it out and in its place sew a graft (tube made of a strong, synthetic material). Depending on the location of the aneurysm, your surgeon may need to detach and reattach your two coronary arteries. This type of open procedure requires cardiopulmonary bypass. This is a procedure where a machine takes over your heart and lung function during surgery.

People with a bicuspid aortic valve or aortic valve disease may also have aortic valve surgery along with aneurysm repair. A surgeon uses a graft with an attached artificial aortic valve or can sometimes repair the bicuspid valve.

Both open and minimally invasive surgeries require general anesthesia.


How can I prevent ascending aortic aneurysms?

You can reduce you risk of an ATAA by:

Outlook / Prognosis

What’s the prognosis (outlook) for people with ascending aortic aneurysms?

Studies show that 79% of people who have elective (non-emergency) surgery for ATAAs survive for at least 10 years after treatment. But the outlook is much worse if an aneurysm dissects or ruptures. About half of these people don’t survive if they don’t have emergency surgery within 48 hours.

Living With

What questions should I ask my doctor if I have an ascending aortic aneurysm?

If you’ve been diagnosed with an ATAA, consider asking your doctor the following questions:

  • How big is the aneurysm?
  • How can I reduce my risk of an aneurysm rupture?
  • Is the aneurysm getting larger? If so, how quickly is it growing?
  • What are the chances that the aneurysm will rupture?
  • Will I need surgery for the aneurysm?
  • What are the risks of aneurysm repair surgery?

When should I contact my doctor?

Seek emergency medical attention immediately if you experience:

  • Coughing up blood.
  • Difficulty breathing.
  • Sudden, severe pain in your chest or upper back.
  • Loss of consciousness, dizziness or stroke symptoms.

A note from Cleveland Clinic

An ascending thoracic aortic aneurysm (ATAA) happens when the first part of your aorta (the main artery in your body) develops a weak spot and bulges outward. People over the age of 65 or those with heart diseases are at the highest risk of getting an ATAA. A ruptured aneurysm can lead to life-threatening internal bleeding. Treatment for unruptured aneurysms usually involves medication or surgery. While most aneurysms don’t cause symptoms, talk to your doctor right away if you experience any problems in your chest or upper back, such as pain or difficulty breathing.

Medically Reviewed

Last reviewed on 10/14/2021.

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