What is an abdominal aortic aneurysm (AAA)?

The abdominal aorta is the main blood vessel that carries blood from the heart to the lower body. In part, the abdominal aorta feeds into the renal arteries, which supply blood to the kidneys.

An abdominal aortic aneurysm (AAA) is a potentially serious medical condition that occurs when a section of the abdominal aorta begins to bulge. If an aneurysm is small it may not require treatment but only monitoring with ultrasound tests, which use sound waves to create images of the blood vessel and show the extent of the aneurysm. However, a large abdominal aortic aneurysm can rupture and is a medically serious event requiring emergency medical care. The survival rate for patients who experience a ruptured abdominal aortic aneurysm is less than 40 percent.

An abdominal aortic aneurysm is a fairly common condition in which the aorta dilates (forms a bulge) causing the aortic wall in that area to become thin and weak. The main risk is that that portion of the aorta could rupture. Once an aneurysm ruptures, it can be deadly.

An abdominal aortic aneurysm is a bulging of the main blood vessel off of the heart. It can occur anywhere along the length of the aorta but is most common just below the arteries that go to the kidneys. This can be felt if big enough just above the belly button. It generally occurs over the age of 65 and can be evaluated with either physical exam or with ultrasound evaluation. There are certain risk factors that increase the risk. This includes any history of smoking, hypertension, high cholesterol, and in those who have had a heart bypass or coronary stents. Treatment is performed with either a stent graft or open surgery. Intervention is typically recommended in those whose aneurysms are 5 cm in size. Without treatment the risk is rupture of the aneurysm that can be fatal.

An abdominal aortic aneurysm, also called AAA or triple A, is a bulging, weakened area in the wall of the aorta (the largest artery in the body) resulting in an abnormal widening or ballooning greater than 50 percent of the normal diameter (width).

The aorta extends upward from the top of the left ventricle of the heart in the chest area (ascending thoracic aorta), then curves like a candy cane (aortic arch) downward through the chest area (descending thoracic aorta) into the abdomen (abdominal aorta). The aorta delivers oxygenated blood pumped from the heart to the rest of the body.

The most common location of arterial aneurysm formation is the abdominal aorta, specifically, the segment of the abdominal aorta below the kidneys. An abdominal aneurysm located below the kidneys is called an infrarenal aneurysm. An aneurysm can be characterized by its location, shape, and cause.