An aortic aneurysm is a weak area in the aorta, the main blood vessel that carries blood from the heart to the rest of the body. As blood flows through the aorta, the weak area bulges like a balloon and can burst if the balloon gets too big. In the past 30 years, the occurrence of abdominal aortic aneurysms (AAA) has increased threefold. Most commonly, aortic aneurysms occur in the portion of the vessel below the renal artery origins. The aneurysm may extend into the vessels supplying the hips and pelvis.
Once an aneurysm reaches 5 cm in diameter, it is usually considered necessary to treat to prevent rupture. Below 5 cm, the risk of the aneurysm rupturing is lower than the risk of conventional surgery in patients with normal surgical risks. The goal of therapy for aneurysms is to prevent them from rupturing. Once an abdominal aortic aneurysm has ruptured, the chances of survival are low, with 80 to 90 percent of all ruptured aneurysms resulting in death. These deaths can be avoided if an aneurysm is detected and treated before it ruptures.
- Approximately one in every 250 people over the age of 50 will die of a ruptured AAA.
- AAA affects as many as 8 percent of people over the age of 65.
- Males are four times more likely to have AAA than females.
- AAA is the 17th leading cause of death in the United States, accounting for more than 15,000 deaths each year.
- Those at highest risk are males over the age of 60 who have ever smoked and/or who have a history of atherosclerosis (hardening of the arteries).
- Those with a family history of AAA are at a higher risk (particularly if the relative with AAA was female).
- Smokers die four times more often from ruptured aneurysms than nonsmokers.
- ;Fifty percent of patients with AAA who do not undergo treatment die of a rupture.
AAA is often called a "silent killer" because there are usually no obvious symptoms of the disease. Three out of four aneurysms show no symptoms at the time they are diagnosed. When symptoms are present, they may include:
- abdominal pain (that may be constant or come and go)
- pain in the lower back that may radiate to the buttocks, groin or legs
- the feeling of a "heartbeat" or pulse in the abdomen
Once the aneurysm bursts, symptoms include:
- severe back or abdominal pain that begins suddenly
- dry mouth/skin and excessive thirst
- nausea and vomiting
- signs of shock, such as shaking, dizziness, fainting, sweating, rapid heartbeat and sudden weakness
Abdominal Aortic Aneurysm – Diagnosis
In some, but not all, cases, AAA can be diagnosed by a physical examination in which the doctor feels the aneurysm as a soft mass in the abdomen that pulses with each heartbeat.
The most common test to diagnose AAA is ultrasound, a painless examination in which a device (a transducer) about the size of a computer mouse is passed over the abdomen. Sound waves are computerized to create "pictures" of the aorta and detect the presence of AAA. Other methods for determining the aneurysm’s size are CT scan (computerized tomography), MRI (magnetic resonance imaging) and arteriogram (real time X-rays).
Reprinted with permission of the Society of Interventional Radiology © 2004, www.SIRweb.org. All rights reserved.