Aorta: Thoracic Aortic Aneurysm

What is a thoracic aortic aneurysm? When an artery wall in the aorta weakens, the wall abnormally expands or bulges as blood is pumped through it, causing an aortic aneurysm. The bulge or ballooning may be defined as a: Fusiform: Uniform in shape, appearing equally along an extended section and edges of the aorta. Saccular aneurysm: Small, lop-sided blister on one side of the aorta that forms in a weakened area of the aorta wall. An aneurysm can develop anywhere along the aorta: Aneurysms that occur in the section of the aorta that runs through the abdomen (abdominal aorta) are called abdominal aortic aneurysms. Aortic aneurysms that occur in the chest area are called thoracic aortic aneurysms and can involve the aortic root, ascending aorta, aortic arch or descending aorta. Aneurysms that involve the aorta as it flows through both the abdomen and chest are called thoracoabdominal aortic aneurysms.

Who is affected by thoracic aortic aneurysms? Thoracic aortic aneurysms affect approximately 15,000 people in the United States each year. Up to 47,000 people die each year from all types of aortic disease; more than from breast cancer, AIDS, homicides, or motor vehicle accidents, making aortic disease a silent epidemic.

Is a thoracic aortic aneurysm serious? A thoracic aortic aneurysm is a serious health risk because, depending on its location and size, it may rupture or dissect (tear), causing life-threatening internal bleeding. When detected in time, a thoracic aortic aneurysm can often be repaired with surgery or other less invasive techniques. Small aneurysms place one at increased risk for: Atherosclerotic plaque (fat and calcium deposits) formation at the site of the aneurysm A clot (thrombus) may form at the site and dislodge, increasing the chance of stroke. Increase in the aneurysm size, causing it to press on other organs, causing pain Aortic dissection, or tearing of the layers of the aorta, a potentially fatal complication and a medical emergency. Aneurysm rupture, because the artery wall thins at this spot, it is fragile and may burst under stress. A sudden rupture of an aortic aneurysm may be life threatening and is a medical emergency

What is an aortic dissection?

Aortic dissection occurs when the layers of the aorta tear and separate from each other. The presence of an aortic aneurysm increases your risk of having an aortic dissection, but aortic dissection can also occur in people with a normal sized aorta.

Aortic dissection can occur suddenly, causing severe sharp, tearing pain in your chest or upper back. Yet, like all types of aneurysms, there may be no symptoms of an aortic dissection.

Most commonly associated with high blood pressure, an aortic dissection forces the layers of the wall of the aorta apart through increased blood flow. If not treated early, aortic dissection weakens the aorta and can lead to a thoracic aortic aneurysm by causing the weakened area of the aorta to bulge like a balloon, stretching the aorta.

If you do experience any symptoms of a thoracic aortic aneurysm or aortic dissection, notify your physician immediately. If left untreated, these conditions could lead to a fatal rupture.

Symptoms of aortic dissection

Most common symptom: Severe pain in the chest (front, back or both).

Less common symptoms: Pain in abdomen, numbness or weakness in one or both legs, loss of consciousness, symptoms of a stroke.

If you have these symptoms, call for emergency help (dial 9-1-1 in most areas).

What causes a thoracic aortic aneurysm?

Thoracic aortic aneurysms are most often caused by atherosclerosis, a hardening of the arteries that damages the artery's walls. While your arteries are normally smooth on the inside, as you age they can develop atherosclerosis. When atherosclerosis occurs, a sticky substance called atheromatous plaque builds up in the walls of the arteries. Over time, excess plaque causes the aorta to stiffen and weaken.Your risk for atherosclerosis increases if you:

Are a smoker

Have high blood pressure

Have high cholesterol

Are overweight

Have a family history of cardiovascular or peripheral vascular disease (a narrowing of the blood vessels)

Certain diseases can also weaken the layers of the aortic wall and increase the risk of thoracic aortic aneurysms, including:

Marfan syndrome (a genetic connective tissue disorder), Loeys–Dietz and other familial connective tissue disorders

Other non-specific connective tissue disorders (characterized by a family history of aneurysms)

Presence of a bicuspid aortic valve

Infections

Inflammatory disease

Rarely, trauma, such as a severe fall or car accident can cause a thoracic aortic aneurysm.

As you age, your risk of developing a thoracic aortic aneurysm increases. More men than women are diagnosed with thoracic aortic aneurysms, and are often affected with the condition at a younger age.

Recent research indicates that a substantial amount of aneurysms have familial patterns, or are inherited from previous generations. It is important to tell your physician if there is a history of aortic aneurysms in your family to ensure that the best preventative screenings are completed.

What are the symptoms of a thoracic aortic aneurysm?

Thoracic aortic aneurysms often go unnoticed because patients rarely feel any symptoms. While only half of those with thoracic aortic aneurysms complain of symptoms, possible warning signs include:

Pain in the jaw, neck, and upper back

Chest or back pain

Coughing, hoarseness, or difficulty breathing

How is a thoracic aortic aneurysm diagnosed?

Early diagnosis of a thoracic aneurysm is critical to managing the condition. The larger the thoracic aortic aneurysm, or the faster it grows, the more likely it is to rupture. The risk of rupture increases when the aneurysm is larger than about twice the normal diameter of a healthy aorta blood vessel.

Diagnosing a thoracic aneurysm is difficult because often there are no symptoms, and often the condition goes undiagnosed until a rupture occurs. If a thoracic aortic aneurysm is suspected, your physician may order the following tests:

Chest x-ray

Computed tomography (CT) scan

Magnetic resonance imaging (MRI)

Echocardiography (an ultrasound of the heart)

Abdominal ultrasound (to look for associated abdominal aneurysms)

Angiography (an x-ray of the blood vessels)

Learn more about these diagnostic tests and procedures