By Geary L. Yeisley, M.D., J.D.
Endovascular Aneurysm Repair or “EVAR” is the treatment of an abdominal aortic aneurysm using a covered stent delivered by a small plastic tube or catheter that enters the arterial system via a small incision in the groin.
The aorta is the largest artery in the body. It starts at the heart and continues down through the chest cavity into the abdomen. The purpose of the aorta is to distribute oxygenated blood pumped by the heart to the organs of the body.
Atherosclerotic disease can weaken the wall of any artery of the body and sometimes results in the “ballooning” of the artery. This ballooning is called an “aneurysm.” One of the dangers of an aneurysm is that it may rupture, resulting in catastrophic injury or death.
Abdominal aortic aneurysms [“AAA”] were traditionally treated by vascular surgeons who would make a large incision in the abdomen, clamp the aorta above and below the aneurysm, and then replace the aneurysm with a tubular synthetic graft. An elective operation to repair a AAA typically takes 3-4 hours and has considerable risks, all of which are less than the risk of mortality if the AAA ruptures. Many patients who rupture their AAA never make it to the hospital.
In the 90’s, the endovascular aneurysm repair [“EVAR”] technique was developed in which a covered stent (think of an expandable wire lattice covered with a synthetic cloth material) is delivered to the aneurysm via a small catheter that enters the arterial system through a small incision in the groin to expose the femoral artery. When the catheter is in position, a balloon is inflated that causes the stent to be deployed and the catheter is withdrawn. The arterial blood then flows through the inside of the covered stent and is no longer applying pressure on the wall of the aneurysm which greatly lessens the risk of rupture.
The procedure is typically performed by vascular surgeons (who have the expertise to convert the procedure to an open procedure if there are any complications), cardiologists, and interventional radiologists. EVAR was so successful that within ten years it was used more often to treat AAA’s than the open surgery technique. The popularity of this procedure is related to the fact that EVAR is performed via a small incision, takes less time, and the recovery time is much shorter.
Unfortunately, not everyone is a candidate for the EVAR procedure. For example, the patients who have a very short area of normal aorta below the renal arteries or have small angulated iliac arteries or small femoral arteries typically are not good candidates because of the technical problems caused by this type of anatomy.
Although considered “minimally invasive,” the EVAR procedure is not without risks. Atherosclerotic disease is a systemic disease that causes problems throughout the body. As a result, myocardial infarction and stroke are always a risk. Other risks include bleeding, kidney failure, decreased blood flow to the intestines, atherosclerotic embolism, and migration of the graft.
Endoleak is a phenomenon that occurs when blood continues to flow or “leak” around the covered stent into the aneurysm sac. If the blood flow into the aneurysm sac is significant and is under pressure, the aneurysm may continue to grow and even rupture.
As always, it is important to ask the physician who is actually performing the procedure about the risks, the number of procedures he/she has performed, the number of procedures that have been performed at that hospital, and their results. You should also consider obtaining a second opinion to confirm that you are a reasonable candidate for the procedure.
(Dr. Yeisley, who is special counsel at Kline & Specter, did his undergraduate studies at Lehigh University, where he was a member of Phi Beta Kappa and graduated magna cum laude. He earned his medical degree at Hahnemann Medical College in Philadelphia, did his general surgical residency at Lehigh Valley Hospital, in Allentown, and did his cardiothoracic surgery residency at Allegheny General Hospital in Pittsburgh. He later returned to practice cardiac surgery at Lehigh Valley Hospital where he was Director of the Open Heart Unit and Chief of the Division of Cardiothoracic Surgery.)