Aortic Aneurysm

Overview

What is an aortic aneurysm?

An aortic aneurysm (say 'a-OR-tik AN-yuh-rih-zum') is a bulge in a section of the aorta , the body's main artery. The aorta carries oxygen-rich blood from the heart to the rest of the body. Because the section with the aneurysm is overstretched and weak, it can burst. If the aorta bursts, it can cause serious bleeding that can quickly lead to death.

Aneurysms can form in any section of the aorta, but they are most common in the belly area (abdominal aortic aneurysm ). They can also happen in the upper body (thoracic aortic aneurysm ). Thoracic aortic aneurysms are also known as ascending or descending aortic aneurysms.

What causes an aortic aneurysm?

The wall of the aorta is normally very elastic. It can stretch and then shrink back as needed to adapt to blood flow. But some medical problems, such as high blood pressure and atherosclerosis (hardening of the arteries), weaken the artery walls. These problems, along with the wear and tear that naturally occurs with aging, can result in a weak aortic wall that bulges outward.

What are the symptoms?

Most aortic aneurysms don't cause symptoms. Sometimes a doctor finds them during exams or tests done for other reasons. People who do have symptoms complain of belly, chest, or back pain and discomfort. The symptoms may come and go or stay constant.

In the worst case, an aneurysm can burst, or rupture. This causes severe pain and bleeding. It often leads to death within minutes to hours.

An aortic aneurysm can also lead to other problems. Blood flow often slows in the bulging section of an aortic aneurysm, causing clots to form. If a blood clot breaks off from an aortic aneurysm in the chest area, it can travel to the brain and cause a stroke. Blood clots that break off from an aortic aneurysm in the belly area can block blood flow to the belly or legs.

How is an aortic aneurysm diagnosed?

Aneurysms are often diagnosed by chance during exams or tests done for other reasons. In some cases, they are found during a screening test for aneurysms. Screening tests help your doctor look for a certain disease or condition before any symptoms appear. Experts recommend screening tests for aneurysms for men who are:

• Ages 65 to 75 and have ever smoked.¹
• At least 60 years old and have a first-degree relative (for example, father or brother) who has had an aneurysm.²

These men are more likely to have an aneurysm than are women or nonsmoking men.

If your doctor thinks you have an aneurysm, you may have tests such as an ultrasound, a CT scan, or an MRI to find out where it is and how big it is.

How is it treated?

Treatment of an aortic aneurysm is based on how big it is and how fast it is growing. If you have a large or fast-growing aneurysm, you need surgery to fix it. In most cases, a doctor will replace the damaged part of the blood vessel with a man-made graft.

Small aneurysms rarely rupture and are usually treated with high blood pressure medicine, such as beta-blockers. This medicine helps to lower blood pressure and stress on the aortic wall. If you don't have surgery, you will have routine ultrasound tests to see if the aneurysm is getting bigger.

Even if your aneurysm does not grow or rupture, you may be at risk for heart problems. Your doctor may suggest that you exercise more, eat a heart-healthy diet, and stop smoking. He or she may also prescribe medicines to help lower high cholesterol.

Frequently Asked Questions

Cause

Abdominal and thoracic aortic aneurysms are caused by a number of factors, including:

• Hardening of the arteries (atherosclerosis). Exactly how atherosclerosis leads to abdominal aortic aneurysms is unclear. It is thought that atherosclerosis causes changes in the lining of the artery wall that may affect oxygen and nutrient flow to the aortic wall tissues. The resulting tissue damage and breakdown may lead to the development of an aneurysm.
• Genetics. In some people who have Marfan's syndrome, Ehlers-Danlos syndrome, or other inherited conditions, the walls of the major arteries, including the aorta , are weakened. Aortic aneurysms run in families.
• Aging. The aorta naturally becomes less elastic and stiffer with age, increasing the risk of an abdominal aortic aneurysm.
• Infections. Infections such as syphilis and endocarditis, an infection of the lining of the heart, can cause aneurysms.
• Injury. A sudden, intense blow to the chest or abdomen, such as hitting the steering wheel in a car accident, can damage the aorta.
• Inflammation. Inflammation of the aorta can weaken the aortic wall. Although researchers have investigated several conditions, what causes the aorta to become inflamed is not clear.

Thoracic aortic aneurysms are much less common than abdominal aortic aneurysms.³ They are often caused by an abnormal breakdown of the elastic fibers in the aortic wall. Other causes of thoracic aneurysms include aortic coarctation (often resulting from a genetic disorder such as Turner's syndrome).

Symptoms

Most people with aortic aneurysms, especially ones in the chest area (thoracic aortic aneurysms ), do not have symptoms. But symptoms may begin to occur if the aneurysm gets bigger and puts pressure on surrounding organs.

Abdominal aortic aneurysm

The most common symptoms of abdominal aortic aneurysm include general abdominal (belly) pain or discomfort, which may come and go or be constant. Other symptoms include:

• Pain in the chest, abdomen, lower back, or flank (over the kidneys), possibly spreading to the groin, buttocks, or legs. The pain may be deep, aching, gnawing, and/or throbbing, and may last for hours or days. It is generally not affected by movement, although certain positions may be more comfortable than others.
• A pulsating sensation in the abdomen.
• A "cold foot" or a black or blue painful toe can happen if an abdominal aortic aneurysm produces a blood clot that breaks off and blocks blood flow to the legs or feet.
• Fever or weight loss, if it is an inflammatory aortic aneurysm.

People younger than age 50 are more likely to have symptoms from abdominal aortic aneurysms than those older than 50.³

Thoracic aortic aneurysm

Symptoms of a thoracic aortic aneurysm are most evident when the aneurysm occurs where the aorta curves down (aortic arch ). They may include:

• Chest pain, generally described as deep and aching or throbbing. This is the most frequent symptom.
• Back pain.
• A cough or shortness of breath if the aneurysm is in the area of the lungs.
• Hoarseness.
• Difficulty or pain while swallowing.

If an aortic aneurysm bursts, or ruptures, there is sudden, severe pain, an extreme drop in blood pressure, and signs of shock. Without immediate medical treatment, death occurs.

The symptoms of aortic aneurysm are similar to the symptoms of other problems that cause chest or belly pain such as coronary artery disease and peptic ulcer disease.

What Increases Your Risk

The leading risk factors for an aortic aneurysm are:

• Advanced age.
• Being male.
• High blood pressure.
• Smoking.
• Family history of abdominal aortic aneurysms in first-degree relatives (parent, brother, or sister).
• Alcohol (more than 2 drinks a day).

When to Call a Doctor

Call 911 or other emergency services immediately if you have signs of a ruptured aortic aneurysm such as:

• Sudden, severe pain.
• An extreme drop in blood pressure.
• Signs of shock.

If you witness a person become unconscious, call 911 or other emergency services and start cardiopulmonary resuscitation (CPR). The emergency operator can coach you on how to perform CPR. For more information about CPR, see the Rescue Breathing and Cardiopulmonary Resuscitation section of the topic Dealing With Emergencies.

Call a doctor immediately if you have:

• A pulsating mass in your abdomen.
• Sudden weakness in the lower extremities on one side of the body.
• Chest pain you have not experienced before.
• A "cold foot" or a black or blue painful toe for no apparent reason.

Call for a doctor appointment if you have:

• Pain in the chest, abdomen, or lower back, possibly spreading to the groin, buttocks, or legs. The pain may be deep, aching, gnawing, and/or throbbing, and may last for hours or days. It is generally not affected by movement, although certain positions may be more comfortable than others.
• Fever or weight loss for no apparent reason.

Who to see

Health professionals who can evaluate symptoms that may be related to an aortic aneurysm and order the tests needed for further evaluation of symptoms include:

• Family medicine physicians.
• Internists.
• Nurse practitioners.
• Physician assistants.
• Cardiologists or vascular surgeons.

If you have a fast-growing aortic aneurysm, you may be referred to a vascular surgeon, who can evaluate your need for surgery.

Exams and Tests

Aortic aneurysms are often discovered during an X-ray, ultrasound, or echocardiogram done for other reasons. Sometimes, an abdominal aneurysm is felt during a routine physical examination. If this is the case, your doctor will perform a medical history and physical examination.

When an aneurysm is suspected or diagnosed, it is important to:

• Pinpoint the location of the aneurysm.
• Estimate its size.
• Determine how fast it is growing and whether surgical treatment is needed.
• Determine whether other blood vessels are involved.
• Detect the presence of blood clots or inflammation.

Tests to help determine the location, size, and rate of growth of an aneurysm include:

• Abdominal ultrasound. Ultrasounds help your doctor know if your aneurysm is growing. If your aneurysm is large, you may need an ultrasound every 6 to 12 months. If your aneurysm is small, you may need one every 2 to 3 years.
• Computed tomography (CT) and magnetic resonance angiogram (MRA), which are used if a view more detailed than an ultrasound is needed. This is important when information is needed about the aneurysm's relation to the blood vessels of the kidney or other organs. Your doctor needs this information especially before surgery. CT is used to watch the growth of a thoracic aortic aneurysm.
• Echocardiogram, an ultrasound exam used to study the heart. A transthoracic echocardiogram (TTE) or a transesophageal echocardiogram (TEE) may be done to diagnose thoracic aortic aneurysm.
• Angiogram. An angiogram can help determine the size of the aneurysm and the presence of aortic dissections, blood clots, or other blood vessel involvement.

One of the most important goals of testing is to estimate the risk that an aneurysm may burst, or rupture, and to compare the risk of rupture to the risks of surgery. If an aortic aneurysm is detected, tests such as abdominal ultrasound can be used to closely follow any change in the size or other characteristics of the aneurysm and help measure the risk for rupture.

Early Detection

Your doctor may recommend an abdominal ultrasound screening test if you are a man who is:

• Age 65 to 75 and has ever smoked.¹
• At least 60 years old and who has a first-degree relative (for example, father or brother) who has had an aneurysm.²

The recommendation does not apply to women or nonsmoking men, because they are less likely to have an abdominal aortic aneurysm. Screening is not considered beneficial for these groups.

People who have Marfan's syndrome, Ehlers-Danlos syndrome, or another condition that puts them at risk may benefit from screening.

Treatment Overview

After you are diagnosed with an aortic aneurysm, your doctor will evaluate:

• Whether you need surgery.
• Whether you will be able to withstand a major surgery.
• Whether you can avoid surgery, at least for the present.

Factors such as the shape and flexibility of the aorta and heart valves are also considered in deciding how to treat an aortic aneurysm.

When surgery is recommended

Aortic aneurysms that are causing symptoms or enlarging rapidly are considered at risk of rupturing. Surgery is usually recommended if either of these factors is present.

In men, surgery is also typically recommended for abdominal aortic aneurysms that are 5.5 cm or larger in diameter. In women, surgery may be recommended for smaller aneurysms. Some doctors perform surgery when the aneurysm is smaller, although the risk of rupture is considered low for aneurysms less than 5.5 cm in diameter.^{4, 5}

Surgery is also recommended when a small aortic aneurysm grows more than 0.5 cm within 6 months.

Surgical repair of thoracic aortic aneurysms is usually recommended when they reach 5.5 to 6.0 cm in diameter.

The decision to have surgery, delay surgery, or not have surgery at all depends on other factors also. These factors may include older age or medical problems that make surgery more dangerous.

Medical treatment for aortic aneurysm

Smaller aneurysms (less than 5.5 cm in diameter) that are not at high risk for rupturing are generally treated with medicine used to treat high blood pressure, such as a beta-blocker. Beta-blockers may decrease the rate at which aneurysms grow. In general, the risks of surgery to repair smaller aneurysms outweigh the possible benefits, because smaller aneurysms rarely rupture.

If surgery is not done to repair your aneurysm, you will have regular tests to see if it is getting bigger.

You may need to take medicine to treat high cholesterol and high blood pressure. While these measures have not been proven to slow aneurysm growth, they can improve your life in other ways. These measures reduce your risk of dying from heart attack and stroke, which kills most (66%) people with aneurysms.⁶ For more information, see the topics High Cholesterol and High Blood Pressure (Hypertension).

Despite some claims, taking antioxidant vitamins has not been proven to reduce the risk of aneurysm or the risk of rupture.

Lifestyle changes for aortic aneurysm

Smoking increases the rate of aneurysm growth by 20% to 25% per year, which significantly increases the risk of rupture.⁶ Your doctor will strongly recommend that you stop smoking and possibly prescribe medicines and therapy to help you do so. Studies show that nicotine replacement therapy, use of the medicine bupropion (Zyban or Wellbutrin), and supportive therapy significantly increase long-term success in quitting.⁷ And if you use a nicotine replacement product or take bupropion or nortriptyline, you can double your chances of quitting for at least 6 months.^{8, 9} Another medicine called varenicline (Chantix) that blocks the effects of nicotine on the brain can also greatly increase your chances of quitting smoking.¹⁰ For more information, see the topic Quitting Smoking. Avoid secondhand smoke too.

Your doctor will probably recommend that you make other lifestyle changes, such as following a heart-healthy diet, limiting alcohol, and exercising. Try to do activities that raise your heart rate. Exercise for at least 30 minutes on most, preferably all, days of the week.

Ongoing Concerns

Aortic aneurysms are hard to detect, as they often do not cause symptoms. Most people with aortic aneurysms are unaware they have them, and they are often diagnosed during an evaluation for another problem.

If you are diagnosed with an aortic aneurysm, you need to monitor its size and rate of growth. Set up regular exams with your health professional and learn all you can about aneurysms, because complications such as rupture or blood clots can be serious.

Living With an Aortic Aneurysm

If you have an aortic aneurysm, you need close medical monitoring and possibly treatment. Talk with your doctor about how often you should come in for testing.

Home treatment is appropriate to help prevent or control conditions that may be causing you to have an aortic aneurysm, such as atherosclerosis or high blood pressure.

• Stop smoking. Avoid secondhand smoke too. Smoking increases the rate of aneurysm growth by 20% to 25% per year, which significantly increases the risk of rupture.⁶ Try nicotine replacement therapy, use of the medicine bupropion (Zyban or Wellbutrin), and supportive therapy. When used together, studies show these methods significantly increase your long-term success in quitting.⁷ For more information, see the topic Quitting Smoking.
• Control high blood pressure. To control high blood pressure, eat a low-sodium diet, and get regular exercise. For more information, see the topic High Blood Pressure (Hypertension).
• Control high cholesterol. To control high cholesterol, eat a low-fat, low-cholesterol diet and get regular exercise. For more information, see the topic High Cholesterol.
• Manage your weight. Losing weight will not likely change the course of an aortic aneurysm, but it may lower the risk of complications if you eventually need surgery. For more information, see the topic Weight Management.
• Exercise. Try to do activities that raise your heart rate. Exercise for at least 30 minutes on most, preferably all, days of the week.
• Limit alcohol. Limit alcohol to no more than 2 drinks a day.

Medications

Medicines used to treat high blood pressure, such as beta-blockers, may be used to slow the growth rate of an aortic aneurysm.

If you have high cholesterol, your doctor might recommend that you take medicines, such as statins, to lower it. Having high cholesterol increases your risk of atherosclerosis, which can cause aortic aneurysms and other conditions, such as coronary artery disease and stroke.

Surgery

Thoracic or abdominal aortic aneurysms that are large, causing symptoms, or rapidly getting bigger are considered at risk of rupturing. Surgery is usually recommended if any one of these factors is present. Your doctor will consider:

• Whether you need urgent surgery.
• Whether you will be able to withstand a major surgery.
• Whether you can avoid surgery, at least for the present.

When making a decision about surgery for an aortic aneurysm, the benefits in relation to the risks of surgery must be considered, as well as the risks of major surgery. People who are at significant risk from surgery may elect to use medical management or another technique such as a stent graft procedure.

Your doctor will closely monitor the size and rate of growth of smaller aneurysms using abdominal ultrasound, computed tomography (CT) scan, or other imaging tests.

Abdominal aortic aneurysms

In men, surgery is typically recommended for abdominal aortic aneurysms that are causing symptoms or that are 5.5 cm or larger in diameter. In women, surgery may be recommended for smaller aneurysms. Some doctors perform surgery when the aneurysm is smaller, although the risk of rupture is considered low for aneurysms less than 5.5 cm in diameter.^{4, 5}

Surgery is also recommended for small aneurysms that have grown more than .5 cm within 6 months.

The decision to have surgery, delay surgery, or not have surgery at all depends on other factors also. These factors may include older age or medical problems that make surgery more dangerous.

Surgical repair of aortic aneurysms

Both traditional surgery and endovascular aortic repair are used to treat aortic aneurysms. Talk to your doctor about which surgery is best for you.

If you have surgery, your doctor will make a large cut in your chest or belly. Then, your aneurysm will be removed and the damaged portion of your blood vessel will be replaced with a man-made graft.

Some aortic aneurysms can be repaired without traditional surgery, using endovascular aortic repair. A tube called a stent graft is inserted through an artery in the groin. The stent graft makes a bridge between the healthy parts of the aorta (above and below the aneurysm). Although this procedure works well right away, experts do not know enough about its long-term effects. Because of this, you will need regular X-rays or CT scans for as long as you have the graft.

Thoracic aortic aneurysms

Your doctor will recommend that you have surgery for a thoracic aortic aneurysm based on the following guidelines:

• If the aneurysm is located where the aorta ascends up out of the heart, surgery is recommended when it reaches 5.5 to 6.0 cm in diameter.
• If the aneurysm is located where the aorta begins to descend, surgery is recommended when it reaches 6.0 cm in diameter.
• In those with Marfan's syndrome, surgery is recommended when the aneurysm reaches 5.5 cm in diameter.
• If the aneurysm causes significant aortic regurgitation, surgery is recommended.

Surgeons and institutions around the country have differing experiences with aortic aneurysms and may follow different protocols in the treatment of the disease. The most important factor to remember is that every case is unique and complicated. You should work with your doctor to decide which treatment is best for you.

If surgery is chosen, your doctor will evaluate your overall health, including assessments of your heart, lungs, and circulatory system, the kidneys, and the gastrointestinal system. The decision whether to have surgery is based on the outcome of these evaluations. The risk of death or injury during the operation increases if other disease is present.

• If the evaluation of your heart indicates that you have significant heart disease, you should undergo coronary artery bypass surgery (CABG) or coronary angioplasty prior to repairing an aortic aneurysm. This is because coronary artery disease is the most important underlying factor contributing to complications, such as heart attack, in the period before and after the operation. Other complications, such as stroke and infection of the graft, can also occur.
• Kidney disease, chronic lung disease, and cirrhosis of the liver may raise the risk of death and complications during the operation.
• Smoking and high blood pressure put a person at a higher risk for complications from surgery. They are also risk factors for the rupture of an abdominal aortic aneurysm.

It is not an option to wait until an aneurysm has ruptured before surgery is done. Most people who have a ruptured aortic aneurysm die. Surgery for a ruptured aneurysm is dangerous because of the large amount of blood loss.

Other Places To Get Help

Online Resource

Organization

Related Information

• Aortic Valve Regurgitation
• Chest Pain
• Coronary Artery Disease
• Early Disease Detection
• Heart Failure
• High Blood Pressure (Hypertension)
• High Cholesterol
• Obesity
• Quitting Smoking
• Stroke
• Weight Management

References

Citations

1. U.S. Preventive Services Task Force (2005). Screening for Abdominal Aortic Aneurysm: Recommendation Statement (AHRQ Publication No. 05-0569-A). Rockville, MD: Agency for Healthcare Research and Quality. Also available online: http://www.ahrq.gov/clinic/uspstf05/aaascr/aaars.htm.

2. Hirsch AT, et al. (2006). ACC/AHA 2005 practice guidelines for the management of patients with peripheral arterial disease (lower extremity, renal, mesenteric, and abdominal aortic): A collaborative report from the American Association for Vascular Surgery/Society for Vascular Surgery, Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology, Society of Interventional Radiology, and the ACC/AHA Task Force on Practice Guidelines (Writing Committee to Develop Guidelines for the Management of Patients With Peripheral Arterial Disease): Endorsed by the American Association of Cardiovascular and Pulmonary Rehabilitation; National Heart, Lung, and Blood Institute; Society for Vascular Nursing; TransAtlantic Inter-Society Consensus; and Vascular Disease Foundation. Circulation, 113(11): e463-e654.

3. Isselbacher EM (2008). Abdominal aortic aneurysms section of Diseases of the aorta. In P Libby et al., eds., Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed., pp. 1458-1469. Philadelphia: Saunders Elsevier.

4. The United Kingdom Small Aneurysm Trial Participants (2002). Long-term outcomes of immediate repair compared with surveillance of small abdominal aortic aneurysms. New England Journal of Medicine, 346(19): 1445-1452.

5. Lederle FA, et al. (2002). Immediate repair compared with surveillance of small abdominal aortic aneurysms. New England Journal of Medicine, 346(19): 1437-1444.

6. Powell JT, et al. (2003). Small abdominal aortic aneurysms. New England Journal of Medicine, 348(19): 1895-1901.

7. Burns P, et al. (2003). Management of peripheral arterial disease in primary care. BMJ, 326(7389): 584-588.

8. Silagy C, et al. (2006). Nicotine replacement therapy for smoking cessation. Cochrane Database of Systematic Reviews (1). Oxford: Update Software.

9. Hughes JR, et al. (2007). Antidepressants for smoking cessation. Cochrane Database of Systematic Reviews (2).

10. Varenicline (Chantix) for tobacco dependence (2006). Medical Letter on Drugs and Therapeutics, 48(1241/1242): 66-68.

Other Works Consulted

• American Heart Association and American College of Cardiology (2006). AHA/ACC guidelines for secondary prevention for patients with coronary and other atherosclerotic vascular disease: 2006 update. Circulation, 113(19): 2363-2372. [Erratum in Circulation, 113(22): 847.]

• Elefteriades JA, et al. (2008). Aneurysms of the aorta section of Diseases of the aorta chapter. In V Fuster et al., eds., Hurst's The Heart, 12th ed., pp. 2308-2314. New York: McGraw-Hill.

• Gornik HL, Creager MA (2007). Diseases of the aorta. In EJ Topol, ed., Textbook of Cardiovascular Medicine, 3rd ed., pp. 1473-1495. Philadelphia: Lippincott Williams and Wilkins.

• Wong DR, et al. (2007). Smoking, hypertension, alcohol consumption, and risk of abdominal aortic aneurysm in men. American Journal of Epidemiology, 165(7): 838-845.

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