By Dr. Allen Douma
Tribune Media Services
Q: I have a calcified aorta that my doctor says supplies blood to my feet. How does this happen? -- N.K., Flushing, N.Y.
A: The calcium in your aorta is probably the result of atherosclerosis. This occurs when fatty substances, called an atheroma or plaque, accumulate on and in the inner wall of an artery.
This buildup of fatty material and other debris reduces the elasticity of the artery and reduces blood flow around the area of accumulation. This material also can break off from the arterial wall, travel in the bloodstream and finally become lodged in a smaller artery, blocking it completely.
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When an artery is blocked, the part of the body served by the artery beyond that point may not receive enough blood. This results in a decrease of oxygen (and other nutrients) delivered to the affected tissue -- a condition known as ischemia. Blockage of coronary arteries is associated with heart attacks, and blockage of carotid arteries and their branches in the brain is associated with transient ischemic attacks (TIAs) and strokes.
The aorta starts at the heart and descends down through the chest and abdomen until it splits into two smaller arteries. Although atherosclerosis can occur anywhere in the aorta, the aorta is most commonly affected where it splits into the two leg arteries.
The narrowing of the arteries blocks blood flow into the leg, and if severe enough, a person will begin to feel pain, aching or a crampy or tired feeling in the muscles of the leg during physical activity. This feeling is known as intermittent claudication. Intermittent claudication is the most common symptom of occlusive arterial disease of the lower aorta and legs. This disorder can affect both legs and, without treatment, tends to get worse, even to the point of requiring amputation.
In addition to the problems associated with arterial blockage due to atherosclerosis, the buildup of calcium in the atherosclerotic plaque can weaken or indicate a weakening of the arterial wall. If this weakening is bad enough, an aneurysm may develop. An aneurysm is a ballooning out of the wall of a blood vessel, and aneurysms almost always occur in arteries.
It's estimated that 6 percent to 9 percent of people older than 65 have an aortic aneurysm. But they almost always go undetected because they rarely cause symptoms. Less than one in 100 people with an abdominal aortic aneurysm will have it rupture. But when an aneurysm does rupture, the person almost always dies.
Although aortic aneurysms are primarily the result of atherosclerosis, there are a number of genetic diseases, such as Marfan's syndrome, that predispose someone to this problem.
Very tall people, such as basketball players, have a greater risk of developing an aneurysm in the upper aorta. However, aortic aneurysms in the abdomen are much more common in the population at large.
Treatment of atherosclerosis begins with prevention -- that is, limiting the controllable risk factors. This means lowering cholesterol, lowering blood pressure, quitting smoking, losing weight and beginning an exercise program. Not much can be done about one uncontrollable risk factor: age.
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Adopting a healthier lifestyle may have some effect on the amount of blockage already present, and it can prevent or limit additional accumulation. Anticoagulants like aspirin may be of some value in reducing part of the blockage associated with clot formation.
The FDA has approved a new medication called cilostazol (brand name: Pletal) for treating people with stable intermittent claudication. It is to be used in conjunction with diet and exercise programs.
Angioplasty (the use of a balloon catheter), surgical clot removal, or bypass or graft surgery may provide more benefit than risk when the claudication is severe enough to greatly interfere with daily activity.
I suggest that to talk with your doctor again about your condition so that you can assess your risks and develop a treatment plan.
Dr. Allen J. Douma writes a daily column on a variety of medical and health issues. Write to him in care of Tribune Media Services, 435 N. Michigan Ave., Suite 1500, Chicago, IL 60611; or contact him at DRFamily@aol.com.
