SAN FRANCISCO — Wing­span stenting in patients with high levels of intracranial stenosis is very successful technically, although its advantages over medical therapy are not yet clear, said investigators who presented findings from a registry funded by the NIH.

“Wingspan stenting in patients with 70% to 99% intracranial stenosis symptomatic is associated with high technical success—97.6%,” said principal investigator Osama Zaidat, MD, who presented the findings at the 2007 International Stroke Conference. “Stenting was also associated with a low periprocedural risk of death, of 4.6% and a lower rate of symptomatic restenosis of 4%.” Dr. Zaidat is an interventional neurologist and an Associate Professor of Neurology at the Medical College of Wisconsin in Milwaukee.

The registry was organized following the Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) study, a medical therapy trial for intracranial arterial stenosis that revealed that aspirin was as effective as warfarin—and safer—for symptomatic intracranial stenosis.  The registry was created in response to the Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arteries (SSYLVIA) study and the FDA’s granting of Humanitarian Device Exemption (HDE) for the Wingspan stent.

TRACKING PERFORMANCE AFTER HDE

Data for the registry were collected between November 2005 and September 2006. The criteria required that patients receiving the stent have a history of either a transient ischemic attack (TIA) or a stroke with 50% to 99% stenosis during antithrombotic therapy. The criteria excluded patients with tandem lesions and those who were being treated for acute ischemic stroke.

The investigators analyzed data only from patients with 70% to 99% stenosis. Among these 131 patients, the average age was 64, 55% were men, and mean follow-up was 3.2 months. Most of the patients, 60%, had had a stroke, and 30% had had a TIA, while the remaining 10% had had an unspecified cerebral ischemic event. The most common location for stenting was the middle cerebral artery, in 33% of patients, followed by internal carotid–intracranial and vertebral artery–intracranial, in 25% each, and the basilar artery in 17%.

HIGH SUCCESS RATE

Technical success, which was defined by the investigators as deployment of the stent with immediate residual stenosis of less than 50%, was reported in 97.6% of the cases. Prestent stenosis averaged 82%, and the immediate poststenting stenosis averaged 20%.

Forty-nine patients (38%) had follow-up angiography, at which point the mean percent diameter stenosis was reported at 28.4%. The frequency of restenosis (defined as greater than 50% stenosis) was 24.5%. However, the symptomatic restenosis rate was 4%.

Six patients (4.6%) had a periprocedural stroke within 24 hours of stent placement. Two patients had an ischemic stroke, while the remaining two had ipsilateral stroke and hemorrhage. One patient had an intracranial hemorrhage alone, and one patient had a fatal pontine stroke. Thirty days after stent placement, three additional strokes were reported, and two additional deaths occurred. One of the deaths resulted from an intracranial hemorrhage, while the other was attributed to unknown cases.

“If you look at the outcome within and after 30 days … the rate of any stroke or death within 30 days or ipsilateral stroke beyond 30 days with a mean follow-up time of 3.2 months was 9.9% in this high risk population,” said Dr. Zaidat.

He cautioned that a comparison of the confidence interval of the stroke rates in the registry and in the WASID high-risk subgroup showed that medical therapy and stenting may yield comparable results. “A randomized multicenter trial is needed to determine whether stenting is superior to medical therapy in high-risk patients with intracranial stenosis,” he added.          

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