Abdominal Aortic Aneurysms
Aneurysms occur most commonly in the aorta, the main artery of the chest and abdomen. The aorta is the body's largest artery and carries blood flow from the heart to all vital organs, and eventually to the legs and feet. Aortic aneurysms are caused by a progressive weakening of the aortic wall which results in a dilatation, or "ballooning" of the vessel. The aneurysm will grow progressively larger and eventually rupture if it is not diagnosed and treated. When an aortic aneurysm ruptures it is a surgical emergency! Many patients do not even survive long enough to make it to the hospital, and among those who do, more than half eventually die of complications. In fact, ruptured aortic aneurysm are the 13th leading cause of death in the US, accounting for more than 15,000 deaths each year. On the other hand, when aortic aneurysms are diagnosed early and treated electively, treatment is safe, effective, and curative. While major surgery has been required to repair aortic aneurysms in the past, newer, less invasive catheter-based technologies using endovascular grafting have made treatment less complicated. It is clear that with the combination of effective diagnosis and the modern treatment of aortic aneurysms countless lives lost due to aneurysm rupture can be avoided.
Major risk factors for abdominal aortic aneurysms ("AAA") include age over 60 years, smoking, and high blood pressure. A family history of AAA is particularly concerning so if any of your direct relatives had an aneurysm, tell your doctor so they can arrange a screening exam. The risk of AAAs increase with age and they are much more common in men than in women. The majority of patients have no symptoms at the time an AAA is discovered. In fact, AAAs are often detected on tests that were performed for entirely different reasons. Although AAA can be detected by physical examination, most are diagnosed today using ultrasound scan or CAT scans, simple exams that are non-invasive and can be done as an outpatient. These exams can tell us whether an AAA is present and how big it is - the key elements to determine the need for treatment.
This angiogram shows an aneurysm of the aorta. The saccular dilation of the wall of the vessel is prone to rupture.
Since major surgery was required in the past to repair an aortic aneurysm, the decision to fix an AAA depended upon a comparison of the risk of rupture with risk of the surgery itself. Most doctors agree that an AAA 5 centimeters in diameter (about the size of a lemon) needs treatment in a patient in otherwise good health. Smaller aneurysms may also need treatment if they cause symptoms (for instance, back or abdominal pain) or follow-up studies have revealed rapid growth of the aneurysm.
The CAT scan produces a cross-sectional "slice" of the abdomen which is used to detect an aneurysm and accurately measure its size. This CAT scan shows a large aortic aneurysm.
Surgical treatment of AAA has been performed routinely for more than 50 years and is one of our most successful and durable operations. In surgery the diseased part of the aorta is replaced with a Dacron or Teflon graft that is carefuly matched to the normal aorta and sewn in place by the surgeon. While ultimately curative, this is an operation that requires a major abdominal incision and general anesthesia, and the hospital stay averages 7-10 days for most patients. Even after uncomplicated surgery, it is often 6-8 weeks before patients can return to a full and normal life. Recent advances in catheter-based technologies have led to groundbreaking treatments for aortic aneurysms.
Now, endovascular grafting technology allows surgeons to repair the AAA by delivering a bypass graft through a small incision in the groin, rather than the traditional major open surgery. The endovascular method allows the tightly wrapped graft to be delivered via a catheter (tube) inserted in a groin artery. In the operating room, using x-rays for proper positioning, the graft is secured in place by inflating a balloon to expand the graft to the size needed to prevent blood flow into the aneurysm. For most patients, the hospital stay is only overnight, with a return to work or normal daily activities in about a week. Even patients with multiple medical problems, once thought "too sick to undergo traditional AAA repair," can have their AAA repaired with an endovascular method, and often be home the next day.
Repair of an aortic aneurysm with an endovascular graft is also performed in the operating room, but surgeons use catheters and x-ray imaging to position the graft.
Endovascular repair of AAA is being performed routinely at the Maryland Vascular Center. A select team of physicians including vascular surgeons and interventional radiologists provide a multidisciplinary approach to treatment and the special skills necessary to handle the most complex problems. If you have an aortic aneurysm and you are in good health, some consideration should be given to elective repair.
If you need AAA repair, some consideration should be given to the use of an endovascular graft. If you have an AAA, or are the family member of a person with AAA and want additional information or want to contact one of our physicians, call 1-800-492-5538, or e-mail us at: MarylandVascularCenter@smail.umaryland.edu