Most of about 16 advisers to the U.S. Food and Drug Administration recommended that the stent, called the Wingspan system, should no longer be available in the market, where it has been sold since 2005.

Wingspan is used to open blocked arteries in the brain when clot-dissolving drugs like aspirin and Plavix do not work. The stent is supposed to improve blood flow and prevent people who have already had a stroke from having another one.

Plavix, known generically as clopidogrel, is made by Bristol-Myers Squibb Co and Sanofi SA.

A study published in the New England Journal of Medicine in September and funded by the National Institutes of Health (NIH) showed the stent may actually do more harm than treating people with drugs and lifestyle changes.

The NIH-funded study was halted after initial results showed stroke patients who were treated with both drugs and the Wingspan stent had more than twice the rate of strokes and death in the month after surgery compared to those treated with drugs alone.

Researchers had expected the use of stents to help patients.

"I'm sensitive to the humanitarian use, and would like to see all alternatives on the table come last resort," said Scott Evans, a researcher and teacher at Harvard University.

"But I did not see any data presentation that would leave me to believe the benefits (of Wingspan) would outweigh the potential harms."

Public Citizen, a watchdog group, in December asked the FDA to withdraw the Wingspan stent from the market.

The panel's advice may not have a huge effect on Stryker, which said it sells less than 2,000 Wingspan stents a year.

But it could have implications for how the FDA deals with drugs or devices after new research shows they may not be as effective or safe as originally thought.

"The credibility of the FDA is on the line," said Dr. Michael Carome, deputy director of Public Citizen's Health Research Group. "Patients will continue to be harmed unless the FDA withdraws its approval."

The FDA said it will make a final decision on Wingspan later, taking into account the panel's recommendations.

OPTIONS FOR PATIENTS

Blocked brain arteries caused by the build-up of fatty deposits called plaque account for more than 50,000 of the 795,000 strokes occurring in the United States each year.

Stroke is the fourth-leading cause of death and a leading cause of disability in the United States.

The self-expanding Wingspan device is the only system currently approved by the FDA for certain high-risk stroke patients. Most of the FDA's advisers said Stryker should keep testing its stent to see which patients would most benefit.

"I'm still concerned ... about that one subgroup of patients where we're backed against the wall and we have no options," said Dr. Larry Goldstein, director of Duke University's Stroke Center.

He said doctors treating patients who do not benefit from anti-clotting drugs would be tempted to use other stents "off-label" in the brain, even if they are not specifically approved for that use. That could be more dangerous than using the Wingspan stent, he said.

Advisers also said some doctors in the NIH-funded study may not have been well trained in implanting stents, skewing the results.

Some patients and doctors also testified during the hearing in favor of Wingspan.

"I am now able to get up every day without having to worry about whether a stroke could possibly kill me," said Greg Zaidel, of Milwaukee, Wisconsin, who said he's had the Wingspan stent for six years.

The FDA originally approved the Wingspan stent under a Humanitarian Device Exemption (HDE), meaning the agency allows up to 4,000 medical devices to be sold each year without requiring stringent evidence of effectiveness. To qualify, the device must address a rare disease or condition, and show "probable" benefit.

The trial supporting approval of Wingspan enrolled 45 patients who had a stroke caused by a blocked blood vessel in the brain and whose medical treatment failed to prevent another stroke.

"We believe data (from other clinical studies) confirm the important role the device plays ... when medical therapy has failed," Stryker said in a statement, adding that it would continue to work with the FDA.

Stryker Corp bought Wingspan as part of its acquisition of Boston Scientific Corp's neurovascular business in 2010.

(Reporting by Anna Yukhananov; editing by Carol Bishopric)

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