The aorta is the main artery in your body. It takes blood from the heart to all the vital organs. It travels through the chest and along the back side of the abdomen, then splits at the level of the umbilicus into the iliac arteries that go to each leg. An aneurysm is a swelling in a blood vessel; it’s bigger than it should be. The most common location for an aortic aneurysm is in the abdomen below the artery branches going to the kidneys. On you, this means just below the rib cage and above the umbilicus. The aorta normally measures 2.5 centimeters (one inch) in diameter in this location. It is called an abdominal aortic aneurysm, or AAA, or “triple A” when it grows to three centimeters or greater.
Risk factors for AAA include male sex, age over 65, high blood pressure, family history of aneurysm, and past or present smoking habit (over 100 packs). Five to eight percent of men over the age of 60 and 30 percent of men over the age of 80 have aneurysms. Currently, the Society of Vascular Surgery supports screening exams for people with multiple risk factors.
We worry about aneurysms because of the risk of rupture. Like a balloon, the larger and larger an aneurysm gets, the greater the risk of rupture. Most people who have a ruptured AAA do not survive, even if they are standing in the hospital when it happens.
The size in diameter is correlated with the risk of rupture. We advise fixing AAAs when they reach 5 centimeters in diameter. At 5 centimeters, the risk of rupture is three to five percent yearly; at 6 centimeters, the risk is 12 percent yearly, and at 7 centimeters, the risk is 25 percent yearly.
There are two ways of fixing aneurysms: open surgery and endovascular stenting. For more on surgery, click here.