Abdominal Aortic Aneurysm
An abdominal aortic aneurysm is an enlarged 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.
Depending on the size and the rate at which your abdominal 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 aortic aneurysm can be risky.
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. Others expand quickly. Predicting how fast an abdominal aortic aneurysm may enlarge is difficult.
As an abdominal aortic aneurysm enlarges, some people may notice:
- A pulsating feeling near the navel
- Deep, constant pain in your abdomen or on the side of your abdomen
- Back pain
If you have any of these signs and symptoms, such as sudden severe back or abdominal pain, get immediate emergency help.
When to see a doctor
You should see your doctor if you have any of the symptoms listed above. The recommendations below are for those who have no symptoms.
Because being male and smoking significantly increase the risk of abdominal aortic aneurysm, men ages 65 to 75 who have ever smoked cigarettes should have a screening for abdominal aortic aneurysms using abdominal ultrasound. If you are a man between ages 65 and 75 and you have never smoked, your doctor will decide on the need for an abdominal ultrasound, usually based on other risk factors, such as a family history of aneurysm. Those with a family history of aneurysm may have an ultrasound at age 60.
There isn’t enough evidence to determine whether women ages 65 to 75 who have ever smoked cigarettes or have a family history of abdominal aortic aneurysm would benefit from abdominal aortic aneurysm screening. Ask your doctor if you need to have an ultrasound screening based on your risk factors. Women who have never smoked generally don’t need to be screened for the condition.
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. Smoking can be damaging to the aorta and weaken the aorta’s walls.
- Hardening of the arteries (atherosclerosis). Atherosclerosis occurs when fat and other substances build up on the lining of a blood vessel. This condition may increase your risk of an aneurysm.
- High blood pressure. High blood pressure can increase your risk of abdominal aortic aneurysms as it can damage and weaken the aorta’s walls.
- Blood vessel diseases in the aorta. Abdominal aortic aneurysms can be caused by diseases that cause blood vessels to become inflamed.
- Infection in the aorta. Infections, such as a bacterial or fungal infection, may rarely cause abdominal aortic aneurysms.
- Trauma. Trauma, such as being in a car accident, can cause abdominal aortic aneurysms.
- Heredity. In some cases, abdominal aortic aneurysms could be hereditary.
Aneurysms can develop anywhere along the aorta, but when they occur in the upper part of the aorta, in the chest, they are called thoracic aortic aneurysms. More commonly, aneurysms form in the lower part of your aorta and are called abdominal aortic aneurysms. These aneurysms may also be referred to as AAA.
Abdominal aortic aneurysm risk factors include:
- Age. Abdominal aortic aneurysms occur most often in people age 65 and older.
- Tobacco use. Tobacco use is a strong risk factor for the development of an abdominal aortic aneurysm and a higher risk of rupture. The longer you’ve smoked or chewed tobacco and the more cigarettes you smoked per day, the greater your risk.
- Being male. Men develop abdominal aortic aneurysms much more often than women do.
- Being white. People who are white are at higher risk of abdominal aortic aneurysms.
- Family history. People who have a family history of abdominal aortic aneurysms are at increased risk of having the condition.
- Atherosclerosis. Atherosclerosis — the buildup of fat and other substances that can damage the lining of a blood vessel — increases your risk of an aneurysm.
- Other aneurysms. People who have an aneurysm in another large blood vessel, such as the artery behind the knee or the thoracic aorta in the chest, may have a higher risk of developing an abdominal aortic aneurysm.
- High blood pressure. High blood pressure may increase your risk of developing an abdominal aortic aneurysm.
Tears in one or more of the layers of the wall of the aorta (aortic dissection) or a ruptured aortic aneurysm are the main complications of abdominal aortic aneurysms. A ruptured aortic aneurysm can lead to life-threatening internal bleeding. In general, the larger the aneurysm and the faster the aneurysm grows, the greater the risk of rupture.
Signs and symptoms that your aortic aneurysm has ruptured may include:
- Sudden, intense and persistent abdominal or back pain, which can be described as a tearing sensation
- Pain that radiates to your back or legs
- Low blood pressure
- Fast pulse
- 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 aneurysms are often 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 also 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.
To diagnose an abdominal aortic aneurysm, doctors will review your medical and family history and conduct a physical examination. If your doctor suspects that you have an aortic aneurysm, specialized tests can confirm it. These tests might include:
Abdominal ultrasound. This test is most commonly used to diagnose abdominal aortic aneurysms. 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, and it can detect the size and shape of an aneurysm.
During a CT scan, you lie on a table inside a doughnut-shaped machine. CT scanning generates X-rays to produce cross-sectional images of your body. Doctors may inject a dye into your blood vessels that helps your arteries to be more visible on the CT pictures (CT angiography).
Magnetic resonance imaging (MRI). An MRI is a painless imaging test that may be used to diagnose an aneurysm and determine its size and location.
In this test, you lie on a movable table that slides into a tunnel. An MRI uses a magnetic field and pulses of radio wave energy to make pictures of your body. Doctors may inject a dye into your blood vessels to help your blood vessels to be more visible on images (magnetic resonance angiography).
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 aneurysms using abdominal ultrasound. Men ages 60 and older with a family history of abdominal aortic aneurysms should consider regular screening for the condition.
There isn’t enough evidence to determine whether women ages 65 to 75 who have ever smoked cigarettes or have a family history of abdominal aortic aneurysms would benefit from abdominal aortic aneurysm screening. Ask your doctor if you need to have an ultrasound screening based on your risk factors. Women who have never smoked generally don’t need to be screened for the condition.
The goal of treatment is to prevent your aneurysm from rupturing. Generally, your treatment options are medical monitoring or surgery. Your doctor’s decision depends on the size of the aortic aneurysm and how fast it’s growing.
If your abdominal aortic aneurysm is small and you’re not experiencing symptoms, your doctor may recommend medical monitoring, which includes regular appointments to make sure your aneurysm isn’t growing, and management of other medical conditions that could worsen your aneurysm. Your doctor will also ask you about any signs or symptoms you may be experiencing that could be related to the aneurysm.
It’s likely your doctor will order regular imaging tests to check on the size of your aneurysm. Expect to have an abdominal ultrasound at least six months after your aneurysm is diagnosed and at regular follow-up exams after the first imaging test. The frequency of your imaging tests depends on the size of the aneurysm, whether the aneurysm is growing and how fast it’s growing.
If you have an abdominal aortic aneurysm, surgery is generally recommended if your aneurysm is about 1.9 to 2.2 inches (about 5 to 5.5 centimeters) or larger. Doctors may also recommend surgery if the aneurysm is growing quickly. In addition, your doctor may recommend treatment if you’re experiencing symptoms such as stomach pain or you have a leaking, tender or painful aneurysm.