Originally created 11/21/02

Filters reduce risk from procedure to clean up neck arteries



CHICAGO -- Doctors have found they can substantially improve the safety of balloon angioplasty to clean out the arteries in the neck by temporarily inserting a tiny filter to trap stirred-up gunk before it floats to the brain.

This approach could make angioplasty the preferred way of treating blockages in the carotid arteries, the main blood vessels to the brain, researchers say.

Currently, doctors usually do this with surgery. That operation, called carotid endarterectomy, is now done on about 200,000 people in the United States annually.

Doctors tested the filter on people considered at especially high risk and found it found it cut strokes and other serious complications in half.

"It is a big deal. I consider it a watershed event," said Dr. Donald La Van of the University of Pennsylvania, who was not involved in the testing.

Dr. Jay Yadav of the Cleveland Clinic led testing of the filter approach using an experimental device called the Angioguard, made by Johnson & Johnson, which paid for the study. He presented the results Tuesday at the annual scientific meeting in Chicago of the American Heart Association.

For a generation, surgeons and heart specialists have debated whose approach works best: surgery or angioplasty.

For the carotid arteries, the surgical approach - opening up the blood vessels and cutting out the bad spots - has been the standard since the 1950s. The goal is to restore blood flow before clogging leads to strokes. However, the operation itself occasionally triggers strokes by loosening particles that get lodged in the brain.

As an alternative, heart specialists sometimes perform angioplasty, similar to the technique widely used to open up blocked heart arteries. A balloon is threaded into the neck artery and briefly inflated to squeeze open the artery. Then a stainless steel wire coil, called a stent, is left behind to keep the artery propped open.

Recent studies suggest angioplasty and endarterectomy are roughly equal in effectiveness and complications. The new study concludes that using the filter makes angioplasty better.

"This is the first time that an interventional procedure has been shown superior to surgery in cardiovascular disease. It's a turning point," Yadav said.

In the procedure, doctors temporarily insert a skinny filter that opens like an umbrella. They do the angioplasty, insert a stent, then collapse the filter, cover it with a tiny sheath and drag it out of the artery. The filter catches lumps of translucent fatty debris stirred up by the stent.

In the study, 307 patients were randomly assigned to get either the angioplasty or surgery. After a month, 6 percent of those getting the angioplasty had died or suffered a stroke or heart attack, compared with 13 percent of the surgery patients.

While longer follow-up is necessary, Yadav said the first month's experience is usually a good indicator of long-term results.

He said that 80 percent of the filters used this way were visibly coated with particles. Typically about half of the filter surface was covered with material that broke loose from the patients' arteries.

In 5 percent to 10 percent of patients, the filter gets so clogged that blood flow to the patients' brains slows considerably. In such cases, Yadav said doctors quickly withdraw the filter before brain damage occurs.

Stents are also used to hold open arteries in the heart after angioplasty. However, in roughly a quarter to a third of cases, those stents quickly clog up again as tissue grows over them.

To help solve that problem, companies are testing stents coated with medicines that prevent this regrowth. Last month, a Food and Drug Administration advisory committee recommended approving the first of these, developed by Johnson & Johnson.

At the heart meeting on Tuesday, Dr. Jeffrey Moses of Lenox Hill Heart and Vascular Institute of New York presented the results of testing on 1,101 patients. After eight months, 9 percent of the new stents had clogged up, compared with 36 percent of the standard variety.

"We achieved an over 75 percent reduction, which is profound and remarkable," Mose said.

On the Net:

Heart meeting: http://www.scientificsessions.org