The Triple A Disease That Can Kill – Abdominal Aortic Aneurysm
03 Jan 2004
A healthy 60 year old man played two sets of tennis and later in the day developed low back pain. He surmised he had simply strained his back. But by evening he experienced severe abdominal pain, lost consciousness and was dead on arrival at the hospital.
A 50 year old woman complained of chest pain after a heavy dinner and believed it was just heartburn. But when pain increased she paid a visit to the hospital emergency. Doctors there suspected coronary attack, but blood tests and an electrocardiogram were normal. Doctors then concluded that the pain was the result of severe indigestion and prescribed Pepcid and a painkiller. But as the patient was leaving the hospital she collapsed and became unconscious. In this case she was at least in the right place at the right time and an emergency operation saved her life . Mention Triple A to Americans and they immediately think of the American Automobile Association. But in this case both patients had developed an abdominal aortic aneurysm (AAA). This triple A disease doesn’t receive much press. But it’s an efficient assassin and lethal unless diagnosed and treated before rupture occurs.
Every year 20,000 North Americans die from this abnormality. Albert Einstein, George C Scott and Lucille Ball all succumbed to a ruptured aortic aneurysm.
The aorta is the main arterial pipeline that delivers blood from the heart to the entire body. It’s about the size of a garden hose and after leaving the heart heads towards the neck for a few inches, then turns and travels down the back of the abdomen. During the last 39 years the risk of developing an abdominal aortic aneurysm has tripled. This is in part due to better diagnostic methods of detecting the problem. But it’s also the result of an aging population.
Studies show that about five per cent of men over age 65 have some degree of AAA. And, although supposedly the stronger sex, AAA is five times more common in males than females.
Since pressure is one factor in causing an AAA it’s not surprising that 80 per cent of patients with AAA suffer from hypertension. Studies show that it’s also more likely to develop in smokers, those suffering from chronic lung disease and when the aorta is weakened by severe atherosclerosis.
Aneurysms may be without symptoms until rupture occurs. But when an AAA reaches 4 cm (1.6 inches) in size a pulsating mass can be felt on abdominal examination, except in obese patients.
The majority of aneurysms continue to expand, but usually at a relatively slow rate. Patients must have the size of the AAA monitored every 6 to 12 months by ultrasound, CT scans and MRIs to detect a change in dimensions.
How to treat an AAA depends on its size. Surgery is usually advised for aneurysms measuring 5 to 5.5 cm since they are likely to rupture. And when an operation is advised experience counts.
Dr. Gilbert Upchurch, a vascular surgeon in Ann Arbor, Michigan, analyzed 3,912 patients who had abdominal surgery for an AAA. His study shows that for this type of surgery expertise is important. It’s the old story that practice makes perfect.
For instance, patients whose aneurysms were repaired by a vascular surgeon in a hospital where many AAA’s were repaired had a mortality rate of 2.2 per cent. For those where the surgeon was doing fewer cases and less experienced the mortality rate was 5.5 per cent.
In recent years some patients with AAA are being treated by stents, devices that provide support to the arterial wall. Rather than using an abdominal incision, the stent is inserted through the femoral artery in the groin and then guided up to the weakened aortic wall.
So what is the best choice? Dr Bruce Perkins, a vascular surgeon at Johns Hopkins Medical School, reports that no one knows the answer at this point. By avoiding abdominal surgery patients have an easier post-operative course. But he stresses insufficient time has elapsed to know whether stents will provide the same good long-time result as patients who had an AAA repaired by abdominal surgery.
