The abdominal aorta is the main blood vessel supplying blood from the heart to the abdomen, pelvis, and legs. When the wall of this vessel is weakened, the pressure of the blood can cause a bulging of the wall, which is an aneurysm.
Who's at Risk for AAA?
Patients at the highest risk for an AAA are males older than 60 years of age with a history of smoking or atherosclerosis. Patients are also at risk if they have a family history of aneurysms. If an aneurysm gets too large, it can rupture and cause significant internal bleeding, which can be dangerous and potentially fatal. The aneurysm may extend into the vessels of the pelvis.
What if an Aneurysm is Discovered?
Once an aneurysm has been discovered, it is important to monitor its size because that will determine when the aneurysm needs to be treated. In general, an AAA will not be treated until it reaches 5 cm in diameter. At that size, the risk of aneurysm rupture becomes greater than the risk of the surgery required to fix the aneurysm (although this is changing with the newer treatment options that are now available).
Diagnostic Tests for Abdominal Aortic Aneurysm (AAA)
- Ultrasound: An ultrasound is typically the first test performed if a physical examination leads to suspicion of an abdominal aortic aneurysm. In addition, men between 65 and 75 years of age with a history of smoking and patients with a family history of an abdominal aortic aneurysm are eligible for a screening ultrasound examination of the abdomen. This test uses sound waves to directly visualize the abdominal aorta in order to determine if an aneurysm is present.
- Computed Tomography (CT): Once an aneurysm has been detected, a CT scan is often performed for further evaluation. This test enables definitive measurements of the aneurysm to be made, which is important since treatment decisions are often based on the size of the aneurysm. The CT scan can also help determine the extent of the aneurysm relative to the renal arteries and whether or not it involves the arteries of the pelvis. Both of these facts will help determine the most appropriate treatment option.
Interventional Treatments for AAA
- Observation: If the aneurysm is smaller than 5 centimeters, not rapidly growing, and not causing symptoms, then it will not require immediate treatment. In this case, regular follow-up with imaging tests such as ultrasound or CT is recommended to monitor the size of the aneurysm.
- Endovascular Repair
- Surgical Repair
Additional Abdominal Aortic Aneurysm Information
The aorta is the main artery in the body that runs from the heart through the chest and into the abdomen. This artery gives off blood vessels to the arms, brain, spinal cord, large and small intestines and kidneys before it splits into two vessels (the common iliac arteries), each of which supply blood to the legs. The most common site for aneurysm formation is in the aorta just below the arteries bringing blood to the kidneys (which are called the renal arteries). This portion of the aorta is called the infrarenal abdominal aorta.
Abdominal aortic aneurysms (AAA) are present in 5-7% of people over the age of 60 in the United States and approximately one in every 250 people over the age of 50 will die of a ruptured AAA. Men are 4X more likely to have this condition than women. Smoking is a significant risk factor for AAA and people who have a family history of aneurysms are also at higher risk. Aneurysms are most commonly discovered when routine tests are performed on the abdomen looking for other problems such as kidney stones, gallstones, back problems, or bowel problems.
How Aneurysms Form
Aneurysms can form anywhere along the arterial tree due to degeneration within the wall of the artery. This degeneration makes the wall thinner and weaker allowing the artery to expand and become an aneurysm. As the wall becomes weaker, the aneurysm becomes larger and the risk of rupture increases (like a balloon). While aneurysms typically enlarge over time, they do not grow in a constant and predictable fashion. That is why it is important to follow patients with small aneurysms with regular ultrasound or CT examinations.
Treatment of AAA
Most physicians will usually observe smaller aneurysms because the risk of rupture is tied to the size and rate of growth of the aneurysm. Therefore, the decision to repair a AAA will depend on these factors in addition to the overall medical condition of the patient. Imaging studies are very important in order to document the overall size of the aneurysm and the rate of growth from year to year.
Treatment options include surgery or endovascular repair using an endograft, which is a newer and minimally invasive technique used to treat this problem. Treatment is typically associated with excellent results and patients should seek consultation with a certified vascular specialist in order to best assess their risk factors and options for therapy.
At our AAA clinic, our interventional specialists will counsel you about treatment options and steps you can take to reduce your rupture risk. We will track any changes in your AAA and will communicate with your physician about your progress. Initially, you will be seen at six month intervals; once the AAA has been stable for 12 months, you will only need to be seen yearly.
For more information or to schedule your appointment with our AAA Clinic, please call 518-262-5149.
