DEAR DR. GOTT: I am 84 years old and have carotid-artery disease. I had an endarterectomy on the right side of my neck. My doctor checks the left side by ultrasound every three months. Right now, the blockage is borderline, but I am told that more surgery will be necessary if it worsens. Is there any way to clear the other carotid artery without having more surgery?

DEAR READER: When fat and plaque build up in the carotid arteries, the condition is known as carotid-artery disease. These buildups cause the arteries to become narrower. Over time, the narrowing may cause too little blood to reach the brain, resulting in a stroke. The same can happen if a clot forms or if a piece of the buildup breaks off and travels into the smaller vessels of the brain.

Family history, smoking, diabetes, age, an elevated LDL and high blood pressure all increase the risk of developing the condition. Usually, there are no symptoms of carotid narrowing, but warnings of impending stroke may occur. A transient ischemic attack (TIA) is often a first sign and is a strong indicator of carotid-artery disease. Symptoms of a TIA are similar to those of a stroke but usually do not cause permanent damage.

Once diagnosed, treatment depends on the severity of the blockage.

The first step is lifestyle modification. A low-fat, low-salt diet is necessary to reduce cholesterol and fat buildup. Smoking should be discontinued and alcohol intake reduced or eliminated. Those with high cholesterol, hypertension or diabetes should be monitored closely and controlled or treated.

Next, anticoagulant medication may be prescribed. In many cases, this is simply over-the-counter aspirin, but prescription medication, such as warfarin or clopidogrel, may be used. This is given to reduce the "stickiness" of the blood and reduce the risk of developing blood clots that may cause heart attack or stroke.

Finally, surgery is available for those with severe buildup that restricts blood flow and oxygen to the brain. The standard surgical procedure is an endarterectomy. During this operation, the blocked artery is opened, the blockage and any damaged portion of the vessel are removed, and the incision is closed.

There is also research being done on carotid stents. These are similar to the stents placed in the arteries of the heart. A stent holds the artery open and usually contains wire mesh to collect debris, such as pieces of plaque or small clots, to prevent them from reaching the brain. It is not currently known how effective and safe carotid stenting is, but it is hoped this will offer a less invasive treatment option.

Return to your doctor to discuss what steps you can take to prevent further plaque buildup. I also urge you to exercise regularly and modify your diet to reduce your salt, fat and cholesterol intake. If you smoke or drink, reduce or eliminate the habits. If you have a history of any other medical conditions, be sure they are well controlled.