Surgery for small asymptomatic abdominal aortic aneurysms.

An aneurysm is an abnormal ballooning of an artery. One site in which this occurs is in the abdominal aorta, which is the major artery running through the abdomen. Some abdominal aortic aneurysms (AAA) present as an emergency and require surgery; others remain asymptomatic. Treatment of asymptomatic aneurysms depends on a number of factors, one of which is size. The risk of rupture increases with aneurysm size. Large asymptomatic aneurysms (>6 cm diameter) are operated on; small aneurysms (<4 cm diameter) have regular ultrasound to monitor growth.