Abdominal aortic aneurysm

Definition 

An abdominal aortic aneurysm is a weakened and bulging area in the lower part of the aorta, the major blood vessel that supplies blood to the body. The aorta, about the thickness of a garden hose, runs from your heart through the center of your chest and abdomen. Because the aorta is the body's main supplier of blood, a ruptured abdominal aortic aneurysm can cause life-threatening bleeding. Although you may never have symptoms, finding out you have an abdominal aortic aneurysm can be frightening.
Most small and slow-growing abdominal aortic aneurysms don't rupture, but large, fast-growing abdominal aortic aneurysms may. Depending on the size and rate at which the aortic aneurysm is growing, treatment may vary from watchful waiting to emergency surgery. Once an abdominal aortic aneurysm is found, doctors will closely monitor it so that surgery can be planned if it's necessary. Emergency surgery for a ruptured abdominal aneurysm can be risky.

Symptoms

Abdominal aortic aneurysms often grow slowly and usually without symptoms, making them difficult to detect. Some aneurysms will never rupture. Many start small and stay small, although many expand over time. Some aortic aneurysms enlarge slowly, increasing less than half an inch (1.2 centimeters) a year. Others expand at a faster rate, which increases the risk of rupture. How quickly an aortic aneurysm may enlarge is difficult to predict.
As an aortic aneurysm enlarges, some people may notice:

• A pulsating feeling near the navel
• Tenderness or pain in the abdomen or chest
• Back pain

When to see a doctor
You should see your doctor if you have any of the symptoms listed above.
Anyone age 60 and older who has risk factors for developing an aortic aneurysm should consider regular screening for the condition. Men ages 65 to 75 who have ever smoked cigarettes should have a one-time screening for abdominal aortic aneurysm using abdominal ultrasound. Men age 60 and older with a family history of abdominal aortic aneurysm should also consider screening.
If you have a family history of aortic aneurysm, your doctor may recommend regular ultrasound exams to screen for the condition.

Causes

Most aortic aneurysms occur in the part of your aorta that's in your abdomen. Although the exact cause of abdominal aortic aneurysms is unknown, a number of factors may play a role, including:

• Tobacco use. Cigarette smoking and other forms of tobacco use appear to increase your risk of aortic aneurysms. In addition to the damaging effects that smoking causes directly to the arteries, smoking contributes to the buildup of fatty plaques in your arteries (atherosclerosis) and high blood pressure. Smoking can also cause your aneurysm to grow faster by further damaging your aorta.
• High blood pressure. High blood pressure, especially if poorly controlled, increases the risk of developing an aortic aneurysm. This is because high blood pressure can damage and weaken your arteries.
• Infection in the aorta (vasculitis). In rare cases, aortic aneurysm may be caused by an infection or inflammation that weakens a section of the aortic wall.

Aneurysms can develop anywhere along the aorta, but when they occur in the upper part of the aorta, they are called thoracic aortic aneurysms. More commonly, aneurysms form in the lower part of your aorta, and are called abdominal aortic aneurysms. Rarely, an aneurysm can occur in between the upper and lower parts of your aorta. This type of aneurysm is called a thoracoabdominal aneurysm.

Risk factors

Abdominal aortic aneurysm risk factors include:

• Age. Abdominal aortic aneurysms occur most often in people age 60 and older.
• Tobacco use. Tobacco use is a strong risk factor for the development of an aortic aneurysm. The longer you've smoked or chewed tobacco, the greater your risk.
• High blood pressure. Increased blood pressure damages the blood vessels in the body, raising your chances of developing an aneurysm.
• Atherosclerosis. Atherosclerosis, the buildup of fat and other substances that can damage the lining of a blood vessel, increases your risk of an aneurysm.
• Being male. Men develop aortic aneurysms much more often than women do. However, women with aortic aneurysms have a higher risk of rupture than do men.
• Race. Aortic aneurysms occur more commonly in whites than in people of other races.
• Family history. People who have a family history of aortic aneurysm are at increased risk of having one. People who have a family history of aneurysms tend to develop aneurysms at a younger age and are at higher risk of rupture.

Complications

Tears in the wall of the aorta (dissection) and rupture of the aneurysm are the main complications of abdominal aortic aneurysm. A ruptured aortic aneurysm can lead to life-threatening internal bleeding. In general, the larger the aneurysm, the greater the risk of rupture.
Signs and symptoms that your aortic aneurysm has burst include:

• Sudden, intense and persistent abdominal, chest or back pain
• Pain that radiates to your back or legs
• Sweatiness
• Clamminess
• Dizziness
• Low blood pressure
• Fast pulse
• Loss of consciousness
• Shortness of breath

Another complication of aortic aneurysms is the risk of blood clots. Small blood clots can develop in the area of the aortic aneurysm. If a blood clot breaks loose from the inside wall of an aneurysm and blocks a blood vessel elsewhere in your body, it can cause pain or block the blood flow to the legs, toes, kidneys or abdominal organs

Abdominal aortic aneurysm

Definition

An abdominal aortic aneurysm is a weakened and bulging area in the lower part of the aorta, the major blood vessel that supplies blood to the body. The aorta, about the thickness of a garden hose, runs from your heart through the center of your chest and abdomen. Because the aorta is the body's main supplier of blood, a ruptured abdominal aortic aneurysm can cause life-threatening bleeding. Although you may never have symptoms, finding out you have an abdominal aortic aneurysm can be frightening.
Most small and slow-growing abdominal aortic aneurysms don't rupture, but large, fast-growing abdominal aortic aneurysms may. Depending on the size and rate at which the aortic aneurysm is growing, treatment may vary from watchful waiting to emergency surgery. Once an abdominal aortic aneurysm is found, doctors will closely monitor it so that surgery can be planned if it's necessary. Emergency surgery for a ruptured abdominal aneurysm can be risky.

Abdominal aortic aneurysm

Tests and diagnosis

Most abdominal aortic aneurysms are found during an examination for another reason. For example, during a routine exam, your doctor may feel a pulsating bulge in your abdomen, though it's unlikely your doctor will be able to hear signs of an aneurysm through a stethoscope. Aortic aneurysms are often found during routine medical tests, such as a chest X-ray or ultrasound of the heart or abdomen, sometimes ordered for a different reason.
If your doctor suspects that you have an aortic aneurysm, specialized tests can confirm it. These tests might include:

• Chest X-ray. Your doctor may first notice you have an abdominal aortic aneurysm by looking at chest X-ray images. Your doctor may order a chest X-ray as a first test to check for problems with your aorta, or your doctor may discover an abdominal aortic aneurysm on X-ray images ordered to check for another condition.
• Abdominal ultrasound. This exam can help diagnose an abdominal aortic aneurysm. During this painless exam, you lie on your back on an examination table and a small amount of warm gel is applied to your abdomen. The gel helps eliminate the formation of air pockets between your body and the instrument the technician uses to see your aorta, called a transducer. The technician presses the transducer against your skin over your abdomen, moving from one area to another. The transducer sends images to a computer screen that the technician monitors to check for a potential aneurysm.
• Computerized tomography (CT) scan. This painless test can provide your doctor with clear images of your aorta. During a CT scan, you lie on a table inside a doughnut-shaped machine called a gantry. Detectors inside the gantry measure the radiation that has passed through your body and converts it into electrical signals. A computer gathers these signals and assigns them a color ranging from black to white, depending on signal intensity. The computer then assembles the images and displays them on a computer monitor.
• Magnetic resonance imaging (MRI). MRI is another painless imaging test. Most MRI machines contain a large magnet shaped like a doughnut or tunnel. You lie on a movable table that slides into the tunnel. The magnetic field aligns atomic particles in some of your cells. When radio waves are broadcast toward these aligned particles, they produce signals that vary according to the type of tissue they are. Your doctor can use the images produced by the signals to see if you have an aneurysm.

Regular screening for people at risk of abdominal aortic aneurysms
The U.S. Preventive Services Task Force recommends that men ages 65 to 75 who have ever smoked should have a one-time screening for abdominal aortic aneurysm using abdominal ultrasound. Men age 60 and older with a family history of abdominal aortic aneurysm should also consider screening.