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Medical Edge Newspaper Column from Mayo Clinic

CAROTID BYPASS SURGERY MAY BE AN OPTION SOMEDAY

DEAR MAYO CLINIC: I had the scare of my life recently, when I suddenly started speaking gibberish during a public-speaking engagement in another city. Thankfully, I recovered, and colleagues got me to the ER, where doctors found a blocked carotid artery. I underwent endarterectomy surgery to open the artery and remove the blockage, but I was surprised that they treated it the way they did. Why isn’t it an option to transplant a new vessel around a blocked artery in the neck like they do with hearts? — Blacksburg, Va.

ANSWER: You ask a very good question.

The National Institutes of Health recently started a clinical trial at 25 neuroscience centers to evaluate the approach you suggest: Improving blood supply to the brain with bypass surgery for carotid arteries completely blocked in the neck. The basic idea is to move a segment of a healthy blood vessel — usually an artery in the scalp — to a branch of the carotid artery. This helps to restore nourishing blood flow to the brain. Centers have just now started accepting patients into the study, so results won’t be known for about five years.

You are correct to think that the bypass idea should have been tried earlier, given the demonstrated benefit in the heart. Indeed, a similar trial was done in the early 1980s, but the results showed that carotid bypass was not effective. But researchers are examining the procedure again — 20 years later — because we now have better imaging technology to determine how much oxygen is getting to the brain. This can help us identify the subset of patients most likely to benefit from carotid bypass.

Blocked carotid arteries cause 61,000 strokes and 19,000 transient ischemic attacks in the United States each year. Stroke is the most dangerous outcome of poor circulation to the brain because it causes permanent brain-tissue damage and impairs function. A TIA is a warning sign that brain blood flow is altered, and a full-blown stroke may occur. Symptoms of TIA last less than an hour, but should be taken seriously because they can predict stroke. See a doctor immediately if you experience any of these TIA/stroke symptoms:

— Difficulty speaking, such as you describe.
— Numbness or weakness of the face, arm or leg on one side of the body.
— Confusion.
— Dizziness or loss of balance.
— A sudden severe headache that may be accompanied by a stiff neck.

John Atkinson, M.D., Neurologic Surgery, Mayo Clinic, Rochester, Minn.

Additional Resources:
Treatment of Carotid Artery Disease
Appointment Information
More Information on Carotid Artery Disease

DEAR MAYO CLINIC: What is sarcopenia? Is it a disease or a natural process? — Bethesda, Md.

ANSWER: The term “sarcopenia” (pronounced sar-ko-PEE-nee-ya) comes from the Greek, “sarco” for muscle, and “penia” for wasting. It refers to the natural biological process in which we gradually lose muscle fiber as we age.

While sarcopenia is not a disease, it can contribute to the development of type II diabetes, obesity and cardiovascular disease. Sarcopenia can also cause muscle weakness and frailty, leading to falls and fractures in older people who have osteoporosis. Sarcopenia is currently a hot medical topic because researchers believe studying it may shed light on the diseases of aging.

Here’s why: Muscle fiber loss begins in our 30s, progresses, and peaks with rapid deterioration in our mid-60s. No one really knows what triggers this process. Studying the sarcopenia cycle may yield key insights.

Here’s how the vicious sarcopenia cycle works: When muscles lose fibers, muscle mass declines, and muscles becomes weak. Weak muscles burn less fuel and promote a more sedentary lifestyle. When a person reduces activity level and loses muscle mass — while eating the same number of calories — he or she becomes overweight.

Excess weight contributes to glucose intolerance — the body’s inability to efficiently break down sugar — which can lead to type 2 diabetes and the “metabolic syndrome.” In addition to increased glucose and reduced insulin action, metabolic syndrome is associated with obesity, changes in blood-fat levels, high blood pressure, and an increased tendency for the blood to clot — all of which lead to increased risk for heart attack and stroke.

K. Sreekumaran Nair, M.D, Ph.D., Endocrinology, and
Director, General Clinical Research Center, Mayo Clinic, Rochester, Minn.

Additional Resources:
Treatment of Sarcopenia
Appointment Information
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Medical Edge from Mayo Clinic is an educational resource and doesn’t replace regular medical care. To e-mail a question, go to www.mayoclinic.org, or write: Medical Edge from Mayo Clinic, c/o TMS, 2225 Kenmore Ave., Suite 114, Buffalo, N.Y., 14207. For health information, visit www.mayoclinic.com.