FDA Staff Pan Brain Stenting System
WASHINGTON -- An intracranial stenting system designed to open blocked arteries in patients who have had a stroke doesn't work any better at preventing future strokes than aggressive medical management, FDA staff reviewers concluded.
They expressed their opinion in briefing documents prepared for the agency's Neurological Devices Advisory Committee, which will meet Friday to vote on whether the benefits of the Wingspan Stent System for intracranial arterial stenosis outweigh its risks.
The Wingspan Stent System, made by Stryker, combines a percutaneous transluminal angioplasty (PTA) balloon catheter with a self-expanding, neurovascular, nitinol stent and stent delivery system.
It is used to improve cerebral artery lumen diameter in patients with intracranial atherosclerotic disease who have failed medical therapy in intracranial vessels with >50% stenosis.
The FDA approved the Wingspan system in 2005 under a Humanitarian Device Exemption (HDE), which allowed the device to be sold without proof of its efficacy, only proof that it is safe and has a "probable benefit of efficacy."
Following approval of the stenting system, the NIH funded a study to compare the stent with medical management.
That was published in the New England Journal of Medicine in September and found that aggressive medical therapy was more than twice as effective in lowering the risk of recurrent stroke or death than was stenting of narrowed intracranial arteries.
That trial -- called the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) -- was halted early because of the significant stroke and mortality rates observed in the stent arm.
All patients had a history of stroke or transient ischemic attack related to significant stenosis (70% to 99%) of a major intracranial artery.
In the SAMMPRIS trial, 14.7% of patients randomized to percutaneous transluminal angioplasty and stenting (PTAS) developed fatal or nonfatal strokes at 30 days compared with 5.8% of patients in the aggressive medical management group ( P =0.002).
Aggressive medical management referred to daily aspirin, 75 mg clopidogrel (Plavix) for 90 days after enrollment, as well as tight control of lipids, blood pressure, and lifestyle factors such as smoking and exercise.