DEAR DOCTOR K:
I had pain in my abdomen, so my doctor did an ultrasound to check for gallstones. It turns out I have an abdominal aortic aneurysm. What is that?
The aorta is the body’s largest artery. It carries oxygen-rich blood from the heart to every part of the body. The aorta curves out of the heart and through the chest, then passes down the center of the body before dividing into the arteries that serve the legs.
An aneurysm is an abnormal swelling and weakening in an artery. An aneurysm that occurs in the aorta as it passes through the middle of the body is called an abdominal aortic aneurysm (AAA).
Like other blood vessels, the aorta can develop atherosclerosis. Harmful cholesterol-filled plaques form, damaging and weakening the artery wall. The constant pressure of blood flowing through the aorta — which is worse in people with high blood pressure — can cause the artery’s wall to bulge where there is a weak spot. (I’ve put an illustration on my website, AskDoctorK.com.)
The majority of AAAs grow very slowly and don’t cause any symptoms. Most AAAs are found by chance during an imaging test performed for another reason, as yours was. Rarely, AAAs cause symptoms such as a deep pain or a throbbing sensation in the back or the side of the abdomen. An imaging test — an ultrasound, CT or MRI scan — then is ordered, which reveals the AAA.
Because AAAs are quite unusual except in high-risk groups, routine imaging studies are not recommended. However, in high-risk groups, screening with ultrasound is recommended. People at high risk for an AAA are men ages 65 to 75 who have ever smoked, or who have a first-degree (parent or sibling) relative who has had an AAA repair (or died from a ruptured AAA).
Smaller AAAs are monitored with regular ultrasound tests. The larger the AAA is, and the faster it grows, the greater the risk that it will rupture. When an AAA ruptures, it causes massive bleeding inside the abdomen. The odds of survival are pretty low. So when an AAA reaches a size that is likely to rupture, it should be repaired.
Until recent years, repair of an AAA involved major surgery. Surgeons opened the abdomen, cut out the diseased section of the aorta, and replaced it with a synthetic tube (typically made of polyester). Today, most AAAs are treated with a minimally invasive procedure known as endovascular repair. The surgeon passes a catheter through a small incision in the leg and threads it into the aorta to reach the AAA. A fabric-coated stent is then put in place to reinforce the bulging aorta, which seals around it.
To avoid an AAA, the same advice for preventing heart disease applies:
- Don’t smoke;
- Eat a healthy diet;
- Exercise regularly;
- Keep your blood pressure and cholesterol in a healthy range.
These habits are also vital if you already have an AAA, because you’ll want to be as healthy as possible if you end up needing surgery.
Abdominal aortic aneurysm (AAA)
An aneurysm is a weakened and ballooning area in an artery. These dangerous bulges can occur in arteries throughout the body, including those in the brain, the back of the knee, the intestines, and the spleen.
But most aneurysms occur in the aorta, the main artery that comes out of the heart and supplies blood to the lower half of the body. About 75% of aortic aneurysms form in middle of the body and are known as abdominal aortic aneurysms or AAAs.