Abdominal Aortic Aneurysm


abdominal aortic aneurysm treatments

An abdominal aortic aneurysm (AAA) usually causes no problems to the patient until it ruptures. Consequently, it is important to identify the patient with an AAA and to repair the aneurysm before it ever causes pain or ruptures.

An AAA may be identified by a pronounced pulsation in the middle of the upper abdomen. One's physician may identify this on a physical exam. However,the majority of AAA's are found incidentally on x-rays (such as an ultrasound, CT scan, or back x-ray) performed for unrelated reasons.

An AAA occurs more commonly in a man than a woman. Most of these patients are older than 60 years and have smoked cigarettes. Many also suffer from coronary artery disease (heart disease), peripheral arterial disease (arterial blockages at other locations), hypertension or lung disease. One has between a 12% and 25% chance of developing an AAA if a first-degree relative (father, mother, brother or sister) has had an AAA.

Diagnosis


An ultrasound scan of the abdomen is very effective at identifying the presence of an AAA and at measuring its maximal size. Men over the age of 60 with a history of smoking should be screened for an AAA with ultrasound. This is particularly the case if he has had a family history of AAA. It is less clear that such an ultrasound screening is necessary in a woman, unless she has had a family history of an AAA.

Once an AAA is identified, it is important to measure its maximum width. The usual width of an aorta is 2 centimeters. An AAA has a very low risk of rupture when under 5 centimeters in width. Recent studies suggest that your vascular surgeon may forestall the surgical repair of your AAA and monitor its status with ultrasound until it reaches a width of 5.5 centimenters, as long as the aneurysm is not painful or growing at a rapid rate. However, once the AAA exceeds this width, a repair of the AAA is indicated.

Treatment


There are two methods of repair. The open surgical approach involves making a large incision into the abdomen in order to expose the aorta and its aneurysm. Clamps are applied to the arteries above and below the aneurysm so that the artery may be directly cut open. The section of artery that is abnormally enlarged is replace by a synthetic tube, which the vascular surgeon sews into place. The clamps are removed and blood flow is restored through the repaired artery. This operation has enjoyed durable success. However, it is a major surgery. There is an approximately 5% chance of fatal complications. The patient usually spends 7-10 days in the hospital and is not back to feeling like their regular self for 2-3 months.

Recent advances in minimally invasive surgery have made the endovascular repair of an AAA possible. Incisions are made in each of the two groins, where the arteries at these locations are exposed. Under x-ray guidance, a device is inserted into the aorta and aneurysm from the arteries in the groin. This device is a stent (a cylindrical metallic frame) covered with a fabric. Once inserted into the proper position, this stent graft replaces the abnormally dilated section of aorta from within. The successful insertion of an aortic endograft by your vascular surgeon has less operative stress on the body, no painful abdominal incision, less blood loss, a lower operative mortality, reduced length of hospital stay, and much faster recovery when compared to the open surgical approach. However, there remains a 5-10% chance that the stent graft may not adequately exclude all blood from flowing in the aneurysm. In these unusual occurrences, further surgery may become necessary. Because of this, a more intensive follow-up is required. Repeat CT scans are obtained.

AAA remains the 10th leading cause of death in men over 55 years of age. This silent killer is largely preventable by early identification. The repair of an AAA has undergone remarkable advancements in the past few years. When an AAA has grown large enough to merit repair, your vascular surgeon now may individualize the treatment to meet your specific needs.

Frequently Asked Questions


Should I get screened for the presence of an AAA?

Death from a ruptured AAA is a preventable event and the screening tool, an abdominal ultrasound, is both painless and reasonably low-cost. A screening ultrasound would make sense if you were a man over the age of 60 (particularly if you have smoked cigarettes or have a family history of AAA). If you are a woman over the age of 60 who has a family history of AAA, then you should also consider a screening ultrasound. Two separate studies from the United Kingdom have shown that deaths due to AAA rupture were reduced between 42% and 68% by implementing such a screening program. The benefit to patient survival from this screening program excedded that derived from screening mammograms and Pap tests for cancer.

 

Is a physical exam sufficient to identify the presence of an AAA?

A physical exam may be sufficient to identify an AAA if you are a very slender person. However, it is very common for other people older than 60 to carry enough weight around their abdomen that a pulsatile aneurysm could escape detection on a physical examination. In most people, an ultrasound is recommended.

 

Is an aortic endograft (endovascular repair of an AAA) experimental?

Aortic endograft repair of an AAA is not experimental. The FDA has approved four separate devices for use in such a procedure. At the Vascular Institute of the Rockies, our team of vascular surgeons is qualified in all four devices. Medicare and other health insurance carriers recognize this procedure for coverage under their policy. Nevertheless, since the technique is reasonably new, refinements in the design of the endograft remain an area of intense research by vascular surgeons. The endograft of the future will likely improve upon those of today.

 

Can I have my AAA repaired with an endograft?

Both patients and their referring physicians are very interested in the endograft repair of an AAA. However, approximately one-half of patients considered for an endograft repair will be declined. This is usually due to the specific size and shape of the aneurysm and adjacent arteries. If specific criteria are exceeded, there is a sizeable risk that the endograft would not work and that the patient would need an open repair. If you wish to be considered for an endograft repair of your AAA, then we would initially obtain a fine-cut CT scan of the abdomen. In some circumstances, you may need an arteriogram. At the Vascular Institute of the Rockies, your vascular surgeon will review these details with a team of specialists and render a recommendation as to whether or not an endograft repair is right for you.

 

How do I decide who should repair my AAA?

The elective repair of your AAA is not an emergency. You have time to evaluate who you want to repair your AAA. The best place to start is to speak with your primary care physician and ask for a recommendation. Your surgeon should be certified in vascular surgery by the American Board of Surgery. In addition, your surgeon should perform major vascular surgery and abdominal aortic operations as a routine part of his or her practice. It is vital that your vascular surgeon have experience and the ability to evaluate you as a candidate for an endograft repair.

 

I have been told that my other medical conditions prohibit a repair of my AAA. Is that correct?

The complications from an AAA repair are more likely to occur if you suffer from other significant medical conditions. This is particularly the case for chronic heart disease, COPD (lung disease), chronic renal insufficiency (kidney disease), and prior stroke. Such conditions may have prompted the conclusion that you could not withstand an open repair of your AAA. However, you should consider having your AAA repaired with an aortic endograft. The likelihood of complications from your other medical conditions will be lessened in comparison to having an open repair of your AAA.