In 2016, strokes killed more than 140,000 people in the U.S., making it the fifth-leading cause of death. The long-standing belief was that doctors only had six hours to save brain tissue, but a new study suggests they may actually have up to 16 hours.
During a stroke, a clot blocks a blood vessel, making it difficult for blood to flow to certain parts of the brain. Typically, doctors administer clot-dissolving medication within the first couple hours then remove what remains of the clot with devices like stents. The earlier a stroke is discovered and treated, the better chance the patient has of recovery.
The study involved 182 people from 38 medical centers in the United States. About half of them received the normal procedure of blood pressure medication, blood thinner, and other medical interventions. The other half received a new procedure as well as the usual medications. Fourteen percent of the people who had the new treatment died—and 45% avoided getting severe disabilities and were able to resume their independence—compared to 26% in the other group.
The procedure, called a thrombectomy, gives doctors more time to save brain tissue where the blood supply may have been cut off, but the tissue hasn’t died yet. The brain imaging technology, developed at Stanford University, uses a dye to show the damaged tissue surrounding dead tissue, allowing doctors up to 16 hours to remove the clot. Here’s Lenny Bernstein reporting for The Washington Post:
“The big news is that we were all wrong in how we were thinking about how strokes evolve,” said Gregory W. Albers, a professor of neurology at Stanford University Medical Center and lead author of the new paper. While some brain tissue dies quickly after a stroke begins, in most patients, collateral blood vessels usually take over feeding a larger area of the brain that is also starved for blood and oxygen, giving doctors many more hours to save that tissue than they previously believed, Albers said.
This would be useful for people who have strokes in their sleep because it’s often hard to pinpoint the exact time of the stroke or for people who live far from a medical center where they can undergo a clot-removing procedure.
Earlier this week, the American Heart Association/American Stroke Association released new treatment guidelines—the first in five years. They also included victims of mild strokes to the population of people eligible for clot-dissolving medication.