An aneurysm is an enlarged portion of a weak area of an artery. Over time, blood flow can cause the weak area to bulge like a balloon. An abdominal aortic aneurysm (AAA) occurs in the abdominal section of the aorta, the main blood vessel that carries blood away from the heart.
Abdominal aneurysms can burst or rupture, causing serious internal bleeding and, if not treated, death. More than 15,000 people die of AAA ruptures in the United States each year. Aneurysms can also unleash damaging blood clots.
The risk for complications increases with the size of the aneurysm. In general, abdominal aortic aneurysms larger than 2 inches (about 5 cm) in diameter should be considered for treatment. Smaller aneurysms should be monitored carefully and regularly for any enlargement.
An abdominal aortic aneurysm (AAA) is an enlargement of a weak area of the aorta, the main blood vessel that carries blood away from the heart. A normal aorta is approximately 1 inch or less in diameter. An aneurysm can grow to be more than 5 inches around. The pressure of blood flowing through the artery can cause the weakened area to enlarge like a balloon. Larger aneurysms are more likely to burst than smaller ones, resulting in internal bleeding that is fatal unless treated immediately.
Because aneurysms can burst or rupture, they are considered a serious health condition.
WHAT ARE THE SYMPTOMS?
Most people with AAA do not feel any symptoms; others may experience one or more of the following:
A rhythmic, pulsating feeling in the abdomen, similar to a heartbeat; or
Deep or severe pain in the abdomen or lower back.
A ruptured aneurysm is life threatening and requires immediate medical attention.
CAUSES AND RISK FACTORS
The cause of AAA is unclear. Some researchers believe that it may be associated with atherosclerosis, or risk factors that contribute to atherosclerosis, such as high blood pressure and smoking.
High-risk populations include:
Men older than 60;
Relatives of patients with aneurysms;
People with high blood pressure;
People with chronic obstructive pulmonary disease; and
People with vascular diseases.
Aneurysms may also be genetic, or rarely, can be caused by trauma, connective tissue disease, or bacterial or fungal infections.
Physicians can only detect about 10 percent of AAAs during a physical examination. Most AAAs are diagnosed using imaging tests, including:
Computed tomography (CT) scans; and
Magnetic resonance imaging (MRI).
Aneurysms that are smaller than 2 inches in diameter and do not cause symptoms may be monitored regularly (approximately every 6 months). People with small aneurysms and high blood pressure may be given medication to lower their blood pressure.
Open aneurysm repair. Surgical repair (often for AAAs that are symptomatic or more than 2 inches around) involves opening the abdomen and replacing the weakened area of the aorta with a fabric tube.
Endovascular graft repair. A minimally invasive procedure, endovascular stent graft repair allows a physician to implant a synthetic tube supported by metal into the aorta. The tube is threaded into the aorta using a catheter inserted through a small incision in the groin. The stent graft relieves pressure on the aneurysm wall. Following an endovascular stent graft, the aneurysm may eventually shrink.