What is an aortic aneurysm?

Dr. David W. Drucker, MD
Cardiologist (Heart Specialist)

Aortic aneurysms are part of the spectrum of peripheral arterial disease (PAD). An aneurysm occurs when cholesterol deposits cause a weakening of the blood vessel wall, which causes an enlargement. The majority of aortic aneurysms are completely without symptoms -- about 75 percent of patients who have aneurysms have no symptoms at all. Because of this, the aneurysms themselves are often found completely incidentally. A typical example of this is when a patient comes to the hospital with a kidney stone. The doctor gets an x-ray, or sometimes a computed tomography (CT) scan, and he or she finds an aneurysm in the abdominal aorta. At that point, the doctor will assess the aneurysm's size and location and decide which treatment, if any, makes the most sense.

An aortic aneurysm occurs when the wall of the aorta weakens. The aorta is the major vessel that carries blood from the heart to the body and has branches that reach all organs in the body. The deepest part of the aorta is the distal arch, which provides blood flow to the upper body and head. If an aneurysm in the aorta bursts, it can lead to death in a matter of minutes.

Doctors perform minimally invasive endovascular procedures to treat aortic aneurysms. However, thoracic aortic aneurysms that reach into the aortic arch are very difficult to treat with minimally invasive endovascular methods because critical blood vessels branch off the aorta in the arch and supply blood to the arms, head and brain. 

Dr. William J. Quinones Baldrich, MD
Vascular Surgeon

An aneurysm is a localized dilation of a blood vessel 50% or more of its normal diameter. In essence, it is the formation of a sack sac or balloon in a segment that should be a tube. Aneurysms can be classified by location, size, shape and cause. Most aortic aneurysms occur in the abdomen, the segment of the aorta that is below the kidney arteries. Only about 5% of abdominal aortic aneurysms involve the aorta above the kidney arteries. In about 25% of patients with abdominal aortic aneurysms there’s also involvement of the iliac arteries or the arteries going to both legs. Aneurysms can occur in the chest if they involve the ascending portion of the aorta,. They’re known as ascending aortic aneurysms. If they involve the segment of the aorta that has the arteries going into the head they’re known as arch aneurysms. When they involve the aorta that comes down toward the abdomen they are known as descending thoracic aneurysms. If the aneurysmal formation occurs in both the chest and the abdomen these are known as the thoracoabdominal aneurysms. 

An aortic aneurysm is a weakening in the wall of the aorta, which causes it to “balloon” or expand in size. Although an aneurysm can develop anywhere along the aorta, most occur in the section running through the abdomen (abdominal aneurysms). Others occur in the section that runs through the chest (thoracic aneurysms).

Aneurysms are often found incidentally during evaluation of other problems since they commonly cause no pain or discomfort. They can silently enlarge for long periods of time without being identified. When the aneurysm gets too large, the wall of the blood vessel can split or tear (aortic dissection/dissecting aortic aneurysm) or even “burst” under the pressure (aortic rupture/ruptured aortic aneurysm).

This content originally appeared online in "The Patient Guide to Heart, Lung, and Esophageal Surgery" from the Society of Thoracic Surgery.

When the wall of an artery becomes thin and weak, it can stretch and bulge like a balloon. This weakened area is called an aneurysm. When it happens in the aorta (the largest artery in the body), it's called an aortic aneurysm. The most common part of the aorta affected by aneurysm is in the abdominal (stomach) area. This is called an abdominal aortic aneurysm, or AAA. Since the aorta is the main artery out of your heart -- carrying blood to all parts of your body -- an aortic aneurysm is a dangerous condition. If it grows large enough or weak enough, the pressure of blood flow can cause the artery wall to rupture. This leads to internal bleeding that can threaten your life.

Unfortunately, aortic aneurysms often produce no symptoms until they rupture. Before rupture, some patients with an AAA may have severe, steady back or abdominal pain that is not relieved by pain medication. Sometimes your healthcare provider can detect a mass in your abdomen.

An aortic aneurysm is a general term for any swelling or dilation of the aorta and usually represents an underlying weakness in the wall of the vessel. Pressure from the blood forces the aneurysm to bulge outward, like a blister. While the enlarged vessel may occasionally cause mild abdominal or back pain, a greater concern is the potential for rupture.

A rupture causes severe pain and may be life threatening without immediate intervention. Surgery involves replacing the weakened section of blood vessel or heart with a patch or an artificial tube called a graft, thus strengthening the weakened wall of the aorta.

Aortic aneurysms are weaknesses or balloonings in the wall of the aorta. Aortic aneurysms require surgical treatment, since they can dissect (tear) or rupture (break open), which are both potentially fatal conditions.
An aortic aneurysm is a ballooning of the major tube that carries blood to the organs; the aorta.  Reasons why aneurysms occur are most commonly from a genetic weakness in the proteins that comprise the aorta. Over time, stress blood pressure issues and straining can exploit the weakness and cause the aorta to stretch. It is important to realize that many patients who have aortic aneurysms do not require immediate surgery. The presence of an aneurysm does necessitate a visit to an aortic specialist and routine surveillance. It is useful to look at an aneurysm as a bad piece of pipe that may require replacement.
Dr. Emily A. Farkas, MD
Cardiothoracic Surgeon

An aneurysm is an enlargement in a blood vessel that can occur anywhere in the body.  When it occurs in the aorta, the largest blood vessel in the body, it is called an aortic aneurysm.  An aneurysm is sometimes referred to as a circumferential ‘swelling’ or ‘dilation’ of the blood vessel.  Although the normal size of the aorta varies with an individual’s age, height, and weight, in most people the diameter of the aorta is not larger than a silver dollar.  When an aneurysm forms, the aorta can enlarge to the diameter of a soda can or even larger.

The aorta exits the heart and travels through the chest and then through the abdomen.  It has branches that come off of the side to provide blood flow to the brain, arms, legs, and every major organ along the way.  When the area of enlargement in the aorta is located in the chest (which is also known as the thorax) then it is called a thoracic aortic aneurysm (often abbreviated TAA).  When the area of enlargement in the aorta is located in the abdomen, then it is called an abdominal aortic aneurysm (often abbreviated AAA).  When the area of enlargement of the aorta is located both in the chest and in the abdomen, then it is called a thoraco-abdominal aortic aneurysm (often abbreviated TAAA).
An aortic aneurysm is a bulging or ballooning of a weakened part of the aortic artery wall. An aneurysm forms when blood pumping out of the heart pushes against and stretches the weakened portion of the aorta wall. When the bulging portion is more than two times the aorta's normal diameter it is considered an aneurysm. Aortic aneurysms are named according to their location:
  • thoracic aortic aneurysms are those that form in the chest cavity
  • thoracoabdominal aneurysms extend from the chest into the abdomen
  • abdominal aortic aneurysms occur in the abdominal portion of the aorta
Regardless of their location, aortic aneurysms are dangerous because of the risk that they will rupture, causing life-threatening bleeding or hemorrhage.

An aortic aneurysm occurs when the aorta stretches out enough to burst.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.