Abdominal aortic aneurysm (AAA) is a dilatation of the major blood artery in the abdomen that directs blood to the intestines, kidneys, liver and to the legs. Aneurysms, or enlarged arteries, can affect arteries throughout the body but tend to occur commonly in the lowest part of the aorta, just above the umbilicus (belly button). The normal aorta is about 2 centimeters (<1 inch). Due to weakness in the artery wall caused by smoking, hypertension or genetic predisposition, the aorta dilates over many years.
Most AAA do not cause any symptoms, but are found on CT scan, ultrasound or MRI exams for unrelated reasons. This can be life-saving if they are found before they burst. When an AAA ruptures, the patient will typically have severe, constant back, side, or stomach pain. Although aneurysms of any size can burst, the risk increases significantly when the diameter exceeds 5 centimeters (2 inches). The chances of surviving a ruptured (burst) AAA are only 25-50%, even if you make it to the hospital. The goal is to repair the aorta before an aneurysm ruptures. Depending on a patient’s medical condition the chances of surviving an elective AAA repair are 95-98%.
Once the aorta is found to be greater than 3 centimeters (cm) we usually follow this with a yearly CT scan. The aortic diameter can also be screened and measured with an Ultrasound test. Exams might be more frequent if the diameter approaches 5 cm.
Treatment is generally recommended patients at 5 cm and 5.5 cm. The treatment options include traditional open surgery or endovascular repair.
-Open surgery involves replacing the aorta with a tube of artificial material, such as Dacron, through an incision in the abdomen or the flank (side).
-Endovascular aneurysm repair (EVAR) has been FDA-approved since 1999. This technique involves placement of stent-supported graft through the groins under X-Ray guidance in the operating room to exclude the aneurysm from the circulation thereby diffusing the threat of rupture.
The decision regarding open versus endovascular repair depends on a number of factors that must be discussed between the patient and all the treating physicians.