DEAR DOCTOR K: What is an abdominal aortic aneurysm? How is it treated?
DEAR READER: An abdominal aortic aneurysm (AAA) is an abnormal swelling in the aorta, the body’s largest artery. It occurs in the part of the aorta between the bottom of the chest and the pelvis.
Most aortic aneurysms come from atherosclerosis. In atherosclerosis, bad LDL cholesterol sticks to the inside wall of the blood vessel, forming plaques that weaken the artery wall. The constant pounding of blood through the aorta may cause the weakened walls to bulge. This bulge is called an aneurysm.
Why is an AAA a problem? Because it can burst. The larger the AAA, the more likely it is to burst. When that happens, blood suddenly spills into the abdomen and blood pressure falls.
The scary thing about an AAA is that it usually doesn’t cause any symptoms until it ruptures. Most AAAs are discovered during routine physical exams or on X-rays for unrelated illnesses.
When an aneurysm is identified, treatment depends mostly on its size. Smaller aneurysms may be monitored with frequent ultrasound tests. These tests check that the aneurysm is not getting larger.
Surgery is almost always recommended for aneurysms larger than 5.5 cm in diameter.
Surgeons have two options to repair AAAs. The traditional method is abdominal surgery: the damaged section of the aorta is cut away and replaced with a plastic patch.
A newer surgical method called endovascular surgery is less invasive. A catheter is threaded into an artery and the tip of the tube is pushed up to the site of the aneurysm. Wrapped around the tube is another cylinder called a graft or a stent.
The doctor who has placed the graft at the site of the aneurysm can then expand the graft until it reaches the wall of the aorta. Now the aorta at the site of the aneurysm has a new, stronger wall. The pressure of blood with each heartbeat is on the strong new wall, and not on the wall that was weakened by the aneurysm.