Rush University Medical Center is the first site in Illinois to use the first stent specifically designed for use in the brain. While it has been possible to attempt to open narrowed brain vessels using existing stents made of stainless steel and intended for use in the heart, the new Wingspan brain stent is designed to be gentler on the more fragile brain vessels.
Using a catheterization procedure, the Wingspan system is guided through the femoral artery in the leg up to the blockage in the brain. A balloon catheter is used to crack open the plaque and then it is withdrawn. The stent, a wire-mesh tube made of superelastic metal, is inserted and maneuvered into the plaque. As the protective sheath is removed, the stent deploys to prop open the artery. It is self-expanding and can curve or taper to fit the specific brain blood vessel.
“Brain vessels are tortuous to navigate through because of their many twists and turns,” said Dr. Demetrius Lopes, a neuroendovascular specialist at Rush and a member of the Chicago Institute of Neurosurgery and Neuroresearch medical group (CINN). “The Wingspan Stent System is more flexible and can be maneuvered so that we can reach areas of the brain we could not treat surgically before.”
Approximately 60,000 Americans suffer strokes each year due to the build-up of plaque in the brain arteries; a condition called intracranial atherosclerotic disease (ICAD). The new stent is designed specifically to access the fragile distal portions of the brain.
“This is a landmark device,” said Lopes “Until now the only treatment option for many patients at risk for stroke was medical therapy such as aspirin. Recent studies have shown that medical therapy is not as effective as we thought.”
The WASID study (Warfarin vs. Aspirin for Symptomatic Intracranial Disease), recently published in the New England Journal of Medicine found that stroke rate in the territory of the symptomatic artery at one year was 12 percent for patients on aspirin and 11 percent for those taking warfarin. The study also found that patients with severe blood vessel blockages of more than 70 percent faced significantly more risk and had a one-year stroke rate as high as 22.5 percent.
“For those patients who are not responding to medical therapy, the Wingspan stent is a welcomed new treatment option,” said Lopes. “Preliminary tests in Europe are very encouraging and show that the stent is better than medication alone.”
The FDA granted the Wingspan Stent System an HDE (Humanitarian Device Exemption) approval on August 4. The HDE allows the use of devices that can treat patients who have no alternative treatment options. Under an HDE, a device is required to show safety and probable benefit, but not effectiveness.
Wingspan received approval based on a 45-patient study at 12 sites in Europe and Asia. The study enrolled patients who had a stroke caused by an intracranial lesion and for whom medical treatment failed to prevent another stroke. The device had a procedural success rate of 97.7 percent. There was a 4.4 percent incidence of death or stroke in the same hemisphere of the lesion at 30 days post procedure. The incidence of death or same hemisphere stroke at six-month follow-up was 7 percent.
The Wingspan stent is intended for patients who have failed medical therapy and have a brain blood vessel blockage greater than or equal to 50 percent of the vessel.
Currently, Wingspan is being introduced to the most experienced neurovascular centers in the country. Lopes is the first fellowship-trained endovascular surgeon in Chicago.