The abdominal aorta is a large blood vessel that supplies blood to the abdomen, pelvis and legs. An aneurysm is when a blood vessel becomes abnormally large or balloons outward. An abdominal aorta aneurysm (AAA, pronounced triple A) repair is a surgery that repairs the damaged vessel. Although the exact cause of AAA is unknown, certain risk factors include: 

• High blood pressure (hypertension)

• Smoking

• High cholesterol

• Obesity

• Emphysema (chronic lung disease)

When an abdominal aortic aneurysm ruptures, it is a true medical emergency. Usually damage occurs in the innermost lining of the artery, which tears and causes blood to leak into the wall of the artery. AAA repair is a relatively rare procedure that requires expertise with the use of complex equipment; technical errors while using the equipment may lead to clinically significant complications, such as irregular heartbeat (arrhythmias), heart attack or death.

A hospital that performs a higher volume of AAA may have more expertise with those procedures, which may result in less of a likelihood of complications. Therefore, a hospital that performs more AAA may have better outcomes for patients that undergo this procedure.