What is an aortic aneurysm?

Gautam Bhatia, MD

Cardiothoracic Surgery

Aneurysms, while rare, are potentially deadly and can cause permanent damage. Emilia Clarke, award-winning actress best known for starring in the Game of Thrones television series, survived not just one but two aneurysms and has spoken out about the resulting damage and long recovery. However, aortic aneurysms, when located prior to bursting, can be treated to prevent a severe or serious injury.

Cardiothoracic surgeon Gautam Bhatia, MD, spoke on aortic aneurysms, how they are diagnosed and how aortic aneurysms are treated.

What is an aneurysm?

“At the most basic level, an aneurysm occurs when there is a bulge or balloon outward of a blood vessel,” said Dr. Bhatia. “The aorta is the main artery that exits the heart and provides oxygenated blood to the entire body, and thoracic aortic aneurysms are defined by where in the aorta they are located, how much aorta is involved and the type of aneurysm.”

Think of the aorta as an upside-down letter U. The ascending aorta would be the left side, blood moving up and into the artery, the arch is, of course, the arch in the center, and the descending aorta is the blood flowing down on the other side. According to the National Institutes of Health, more than 50% of thoracic aortic aneurysms happen in the ascending aorta.

How is an aortic aneurysm diagnosed?

“An artery is deemed aneurysmal when its diameter grows larger than normal,” said Dr. Bhatia. “We define the aorta in the chest as aneurysmal when its diameter reaches 4 centimeters or larger.”

Aortic aneurysms are rare, with those requiring medical intervention happening to around 2 to 4 out of 1,000 people.

Are there risk factors that make you more likely to have an aneurysm?

The most common risk factors for aneurysm include:

• Smoking
• High blood pressure
• High cholesterol
• Genetic conditions

“The most common genetic conditions that we see with thoracic aneurysms include a bicuspid aortic valve, where the heart valve has only two small parts instead of three, familial thoracic aortic aneurysms, where the blood vessel becomes weakened or stretched, and syndromic connective tissue disorders like Marfan syndrome, Loeys-Dietz syndrome and Ehlers-Danlos syndrome, all of which can have negative effects on the function of connective tissue,” said Dr. Bhatia. 

What are the different types of aortic aneurysm?

“The aorta consists of multiple layers, and most aneurysms we deal with are considered true aneurysms and are an enlargement of all the different layers of the aorta,” said Dr. Bhatia. “This enlargement could be genetic, the result of a degenerative condition like atherosclerosis, caused by inflammatory conditions, mechanical due to a blockage in the artery or an aortic aneurysm can occur after surgery.”

There are also what is called ‘pseudoaneurysms,’ or injuries to a blood vessel walled off by surrounding tissues. While still serious, these don’t actually involve a layer of the aorta.

What happens if an aneurysms bursts?

“There are a few different conditions that can result from an untreated aneurysm,” said Dr. Bhatia. “Because a ruptured aneurysm is a severe and life-threatening emergency, we try to avoid this. Surgery can repair the bulge and prevent the rupture.”

A ruptured aneurysm can result in serious complications like hemorrhagic stroke or brain damage. It may be fatal.

What are signs of an aortic aneurysm?

Aortic aneurysms often don’t show any symptoms and are found during testing for other unrelated medical concerns. If the aortic valve is beginning to leak, someone with an unruptured aneurysm might show symptoms of heart failure, like shortness of breath or edema (swelling of the limbs).

If the aneurysm ruptures, a sudden onset severe central chest pain or “tearing” pain between the shoulder blades can occur. Chest pain may also be a symptom of a rapidly growing aneurysm which may need surgical intervention.

If you experience this sudden or tearing pain, call 911 or head to the emergency room immediately.

How are aortic aneurysms typically found? Is there a screening?

“While most unruptured aneurysms are located through screening for other medical concerns, first degree relatives of patients with known aneurysms of the ascending aorta and aortic root should be screened with specialized imaging,” said Dr. Bhatia.

CT scans with IV contrast are the gold standard in identifying and accurately following patients with aortic aneurysms.

Transthoracic echo can also be used to evaluate the aortic root, proximal ascending aorta and aortic valve without radiation, but isn’t always inaccurate in its measurements. It is a useful tool for the initial diagnosis of thoracic aortic aneurysms.

An MRI is another useful tool that can image the entire aorta without radiation, but due to how long an MRI takes, the lack of easy availability for MRIs and the decreased resolution compared to CT, its use for aortic aneurysms is limited.   

How is an aortic aneurysm treated?

“Once an aneurysm is identified, surveillance is a key component to the treatment plan for the patient,” said Dr. Bhatia. “Usually, a CT scan is performed about six months after the initial diagnosis to ensure no rapid growth of a newly diagnosed aneurysm is occurring.”

Annual CT scans and ECHOs are then used to look for any future growth. Keeping up with consistent screening and imaging to keep track of the potential growth of the aortic size helps doctors to identify who may need surgery to prevent a rupture from happening in the future.

Generally speaking, once an aneurysm reaches 5 centimeters in diameter or has a rapid change in size, surgery is recommended, where the bulging area of the aorta is repaired or fully removed and replaced with a graft. 

Since early diagnosis is key to preventing the serious consequences of an aortic aneurysm rupturing, keeping up with heart health and regular screenings is essential, especially if you have a family history of aneurysms occurring or are in any of the higher-risk categories.