A former Food and Drug Administration official is joining public safety advocates in asking the federal government to withdraw a Stryker medical device associated with increased rates of stroke and death.
The consumer watchdog group Public Citizen says a recent study funded by the National Institutes of Health found a 2.5-fold increase in stroke or death with the Wingspan stent system, which is designed to prevent stroke by clearing blood flow to the brain. The group asks the FDA to remove the device from the market in a petition filed Wednesday and co-signed by a former executive from the agency's device division.
"I can see no reason why this device should continue to be available," states Professor Larry Kessler, in a letter accompanying the petition. Kessler spent more than a dozen years in FDA's device division and is currently a professor of health science at the University of Washington.
The FDA approved the device in 2005 under a special program that grants speedy approval to devices for rare diseases and conditions. Stryker Corp., based in Kalamazoo, Mich., recently acquired the stent from its original manufacturer, Boston Scientific. Wingspan consists of a small, mesh metal tube that is braced into place via inflatable tube, promoting blood flow through the arteries to the brain. The device was cleared for patients who have had one stroke and are at risk for additional strokes.
But a study published in September's New England Journal of Medicine found that patients treated with the device were more likely to suffer a second stroke or die within 30 days, compared to patients treated with a combination of blood-thinning medications. The study involved 158 patients who experienced a stroke and were treated with Wingspan, then followed for six months. Their results were compared with those of a separate group of patients who received drug therapy alone.
Public Citizen's petition argues that the FDA should remove the device from the market, and suggests it should not have been approved in the first place. Under the FDA's so-called Humanitarian Device Exemption program, medical implants can be cleared based on preliminary evidence, so long as there is a "reasonable basis" to conclude that the device's benefits outweigh its risks.
Using this program, Public Citizen's Dr. Sidney Wolfe writes that Boston Scientific "was able to gain marketing approval based on a single, uncontrolled trial of just 45 patients that was not designed to demonstrate whether the device was more effective or even safer than medical therapy alone."
Any citizen or group can petition the FDA to remove a product from the market based on safety, economic or environmental reasons. The FDA often takes months or even years to render a decision on such requests.