Abdominal aortic aneurysm is a common disorder of the main blood vessel in the center of the body. An aneurysm is an abnormal enlargement of the blood vessel and may be due to a variety of causes.
The most common reason for abdominal aortic aneurysm formation is the presence of atherosclerosis in the wall of the blood vessel. As the atherosclerotic process advances, the wall of the aorta is weakened and begins to bulge outward.
As it enlarges, the wall is stretched and becomes even weaker, leading to a vicious cycle of rapidly- progressive enlargement. Aortic aneurysm may cause several problems. In some cases, pieces of the atherosclerotic plaque may break off and wash downstream. This is known as the cholesterol emboli syndrome, and it is common in individuals with aneurysm.
The most dreaded complication of abdominal aneurysm is rupture or leaking of the aneurysm. Shock rapidly ensues, and emergency surgery is required. Even in the presence of expert management, aneurysm rupture is frequently fatal.
The diagnosis of abdominal aortic aneurysm is typically made by ultrasound or CAT scan examination of the abdomen. Although physical examination is useful in thin people, in obese people it can be quite misleading. The absence of an aneurysm on physical examination should never stop ultrasound or CAT scan evaluation if an aneurysm is suspected.
When aneurysms reach a size of 5.0-6.0 cm in diameter for males and 4.5-5.0 cm in diameter for females, surgical removal is warranted, as it is estimated that aneurysms greater than 6 cm in diameter have a tendency to rupture at a rate of 25-50 percent per year. Patients who are at risk for abdominal aneurysm are generally those patients who are at risk for atherosclerosis (the elderly, smokers, diabetics, hypertensive individuals and patients with high serum cholesterol values). If you fall into either of these categories, you should discuss the possibility of abdominal aneurysm with your physician during your next visit. The need for further diagnostic evaluation will be determined at that time.