Stents Can Treat, Not Just Prevent Strokes
Stents can be placed in the brain to treat a stroke as it's occurring, suggests preliminary data being presented at the 21st Annual International Symposium on Endovascular Therapy (ISET).
Stents have long been used to open up blocked blood vessels in the heart to prevent heart attacks and in the neck to prevent strokes. More recently stents have been used in the heart to treat occurring heart attacks by opening up the blocked arteries. This early research suggests stents also can be used to treat occurring strokes, by opening up blocked arteries in the brain.
Treatments for ischemic stroke currently include delivering clot-busting drugs to the blockage through the veins or directly into the clot through an artery, or by removing the clot with a tiny corkscrew-like device or vacuuming it out. But early research suggests stents may work better than those treatments.
"Most patients had significant improvement; for instance, they could go home rather than having to be placed in a nursing home, which is pretty dramatic," said L. Nelson Hopkins, M.D., professor and chairman of neurosurgery and professor of radiology at the State University of New York at Buffalo, who is presenting the data at ISET. "Stents seem to work when clot-busters or other mechanical devices can't."
The third-leading cause of death in the U.S., stroke is called a brain attack because blood flow and oxygen to part of the brain is cut off. About 85 percent of strokes are ischemic, meaning they're caused by a blocked blood vessel. About 700,000 people suffer an ischemic stroke every year. The remaining 15 percent of strokes are hemorrhagic and are caused by a broken blood vessel. The lack of blood flow and oxygen to the site of the stroke causes the brain tissue to die. About a quarter of people who suffer a stroke die. Another third are severely disabled and may be paralyzed or lose the ability to speak or remember.
SUNY Buffalo researchers are reporting preliminary results on 16 patients who received stents to treat their strokes as part of a single center Investigational Device Exemption (IDE) from the FDA, with Elad Levy, M.D., as the principal investigator. Stents were placed and opened blocked arteries in the brain in all patients (100 percent) and 11 patients (69 percent) had significant improvement in their stroke symptoms.
Clot-busting drugs only work about half of the time because the blockage can be sticky and adhere to the wall of the artery, making it difficult to break up, said Dr. Hopkins.
Researchers used computed tomography (CT) perfusion to determine if the use of a stent would be beneficial. "With CT perfusion we can tell if the brain is dead or alive," said Dr. Hopkins. "Some patients experience brain death within an hour; others can have a viable brain 24 hours after the stroke starts." In those cases, it may still be possible to place a stent.
Tiny cage-like cylinders, stents are placed minimally invasively by threading a small tube, or catheter, through the arteries to the site of the blockage. A tiny balloon is inflated to open up the blockage. A collapsed stent is then placed at the site, where it expands and acts like scaffolding to keep the artery open.