October 25, 2001
New techniques can keep arteries open longer
For years, it seemed like a rite of passage, like a first car or a first grandchild. At a certain age, a lot of people went into the hospital for cardiac bypass surgery, to relieve narrowing – or stenosis – of blood vessels serving the heart muscle. As medical research advanced, some bypass surgeries were replaced by the use of balloons to open the blood vessel, and still later by the insertion of stents into the arteries.
As Dr. Larry Dean, director of the UW Regional Heart Center, explains, a stent is shaped somewhat like a little metal spring.
“About 3 to 5 percent of the time, balloon angioplasty – using a small balloon to stretch and break up a plaque that may be narrowing an artery – was ineffective. The patient would have to go into emergency bypass surgery.
“When we do a balloon angioplasty, there is trauma to the vessels,” Dean says. “There may be small tears to the vessel that cause some instability, so the vessel closes. If the artery will not stay open, a stent can be installed and will act as a scaffolding to keep the artery open. That has reduced the need for emergency bypass surgery down to half a percent or less of patients undergoing balloon angioplasty.”
Arteries also may re-close months later.
“The second problem is a matter of an over-exuberant response to the healing process, and stents have proven valuable here,” Dean says. “They get the absolute best result that you could possibly get.”
Previous research has shown that the use of a stent reduces the incidence of narrowing, or restenosis, by about 30 percent.
“This means you go from a rate of about 30 percent of coronary patients having restenosis on the average, in the several months following the procedure, to somewhere around 20 percent,” Dean says. “Other modern techniques, aside from using stents, have reduced the overall restenosis rate still further to about 10 to 15 percent of all cases.”
While stents have reduced restenosis rates immensely, there are still some patients who undergo more than one surgical procedure to correct restenosis. New therapies, such as radiation treatment of the affected vessel, are reducing that number.
“Radiation, known as brachytherapy, allows the vessel to heal, but not over-heal, avoiding restenosis,” Dean says. “Researchers are also looking at placing medications directly on the stents, which may reduce restenosis still further.”
Dean says the stents do not treat the underlying disease, so if you have atherosclerosis, you need to take very good care of yourself. That includes following the instructions of your primary care health provider and your cardiologist. Those guidelines usually include staying on a low-fat diet, exercising appropriately, taking prescribed medications for blood cholesterol problems, and stopping smoking.
“Everyone would like to be able to have that golden bullet that takes care of their problems without them having to do anything, but that’s not going to happen with most diseases,” Dean says. “Active participation by the patient is very important in determining how he or she will do in the long term.”
