Updated Dec. 22, 2011, at 12:30 p.m. to include comments from Stryker.

Consumer watchdog group Public Citizen asked the federal government to recall Stryker Corp.’s (NYSE:SYK) Wingspan brain stent over concerns that it may lead to heightened risk of stroke and death.

Former FDA medical device director Larry Kessler joined the petition, asking that the agency pull the stents off the market and revoke their 510(k) clearance "because, when combined with aggressive medical treatment, they provide no additional benefit but cause significantly more harm than safer aggressive medical treatment alone," according to the petition.

The Wingspan system, cleared under the FDA’s humanitarian device exemption pathway in 2005, places a stent in narrowed arteries supplying blood to the brain.

Stryker is currently the only company with the FDA’s okay to sell a brain stent for certain high-risk patients in the U.S., having acquired it as part of a  $1.5 billion cash buyout of Boston Scientific Corp.’s (NYSE:BSX) neurovascular business in October of last year.

Among growing concern resulting from the National Institutes of Health SAMMPRIS study, the Kalamazoo, Mich.-based orthopedics giant defended the stent system, noting that the NIH study didn’t consider the device as it’s intended to be used.

"The SAMMPRIS trial did not follow the current HDE indication for use; it focused on studying the treatment of severe intracranial atherosclerotic disease, early in the treatment lifecycle and with an aggressive drug treatment regimen and rigorous oversight of medication compliance," Stryker spokeswoman Tamara Cutler told MassDevice in an email, adding that the system is cleared for use in no more than 4,000 patients per year.

"Stryker is committed to partnering with the NIH, FDA and study leaders to better understand and interpret the SAMMPRIS trial results," Cutler told us.

HDE standards for effectiveness are less stringent than pre-market approval submissions, and Boston Scientific won clearance with a single trial of 45 patients, Public Citizen wrote. The device is cleared for high-risk patients who have suffered one stroke and are likely to experience another.

"I can see no reason why this device should continue to be available," Kessler wrote in a letter in support of Public Citizen’s petition. "I understand that the FDA needs to use its regulatory authority in flexible and not dogmatic ways and granting of HDEs when data about safety and effectiveness are not complete is a legitimate exercise of regulatory authority. However, for that flexibility, the FDA must realize it has an equally important duty to move swiftly to make regulatory changes and announcements when device problems are uncovered."

Kessler spent more than 6 years as the director for the Office of Surveillance & Biometrics and another 6 years as director for the Office of Science & Engineering Laboratories at the Centers for Devices & Radiological Health at the FDA.

Public Citizen’s beef arises from recent research finding that patients treated with blood thinners and lifestyle coaching had lower rates of stroke and death than those who received the medication, guidance and the Wingspan brain stent.

"Stroke specialists are all disappointed that stenting did not have the beneficial impact we thought it would have," principal investigator at the University Hospital Case Medical Center arm Dr. Cathy Sila said in a press release in Sept. "The group that received aggressive medical therapy alone did far better than predicted with a 30 day stroke and death rate of only 5.8%. However, the group that received a stent as well as aggressive medical therapy did worse than predicted with a rate of 14.7%."

After one year, the stroke and death rate rose to 12.2% for the non-stented group and 20% for the patients who received the device, according to the study, which was sponsored by the National Institutes of Health and published in the New England Journal of Medicine.

"These compelling postmarket data about the Wingspan stent provide an opportunity for the FDA to show to industry, the clinical community, and most of all to patients that the Agency is serious about exercising its authority by withdrawing the HDE immediately and insisting on a recall to ensure the devices on the US market are both safe and effective.

Kessler was critical of the FDA for what he viewed as a lapse in action regarding recent studies warning of heightened risks of the Wingspan stents.

"I have looked at the FDA website and tried to find out whether the agency has even warned clinicians using a Medical Device Safety Communication," he wrote. "I cannot locate such a notice and would ask the FDA to explain why they have been so silent in the face of this significant trial showing clear concerns about this regulated medical device."

Public Citizen, a watchdog group founded by Ralph Nader, has also recently spoken out against transvaginal mesh products, asking the FDA to recall them after the agency released warnings that the device may expose patients to unnecessary risk without offering clinical benefit above safer options.