Making this decision is presently very difficult since AAAs afflict mainly those over 60 years of age. The standard surgical procedure to repair an AAA involves a large abdominal incision. Recently, vascular surgeons at UPMC have used a minimally invasive procedure called endovascular surgery in which the aneurysm is repaired from inside the aorta using a catheter. The catheter contains a collapsed polyester tube which is inserted into the patient's femoral artery and moved to the site of the aneurysm. Once inside the aneurysm, a spring-type attachment system hooks the tube to the inside walls of the artery on either end of the aneurysm and is anchored into place.
Blood then flows through the implant, effectively depressurizing the aneurysm.
Endovascular surgery is still a new, exploratory field and only a small percentage of patients are eligible for this technique. Therefore, the only option for most patients is to undergo traditional surgical repair, according to Dr. Vorp. Some AAAs may have the same maximum diameter, but may have differences in shape, wall thickness, or mechanical properties which could have an effect on their growth and potential to rupture. That is, a more sound indicator of the severity of a specific aneurysm is to compare the acting wall stresses to the tensile strength of the wall tissue, since AAA rupture occurs when the wall stresses exceed the strength. Dr. Vorp and his team have developed a technique to noninvasively assess the wall stresses acting in individual AAAs based on the patient's blood pressure and the virtual AAA, a three-dimensional reconstruction of CT scans taken prior to surgery.