Stem Cells: A Breakthrough in Stroke Treatment?
The world of stroke treatment is changing at an increasingly rapid pace. Novel stem cell therapies are producing remarkable — and surprising — results. The upside for patients: a faster and fuller recovery.
Millions of brain neurons die within minutes following a stroke, and the dead cells can’t be restored. Nonetheless, the brain tissue surrounding the dead area, although non-functioning, remains alive for a short time, said Dileep R. Yavagal, M.D., professor of clinical neurology and neurosurgery, and chief of interventional neurology at the University of Miami Miller School of Medicine. Surprisingly, research has found that stem cells target the area and secrete chemicals that save the tissue and, essentially, rejuvenate it.
“Mother Nature repairs brain tissue in every stroke patient,” Yavagal said. “But, given the complexity of the brain, the repair is very inadequate in most cases.”
Yavagal is working with stem cells in an effort to improve upon Mother Nature. His lab is the first to show a safe and effective method to deliver stem cells into distant brain arteries in the area of a stroke that set up powerful “drug factories” to fuel the repair process, magnifying what the body is already doing to fix itself. Yavagal co-authored an article in The Lancet Neurology about the clinical trial he led at the Miller School, called MASTERS, in which bone-marrow-derived stem cells were given intravenously to stroke patients.
In this phase 2 clinical trial, 129 patients received the stem cells, which were obtained from healthy donors, between 24 and 72 hours after the stroke began. The approach was found to be safe, and although not all patients showed clear benefit, those getting cells within the first 36 hours had “significant benefit in decreasing disability at three months of recovery from stroke.”
The subgroup of patients in the trial who benefitted was too small to conclusively prove the benefit of stem cells, but Yavagal still called the finding “very promising.” The additional healing effect of the stem cells may also enable stroke patients to recover more quickly than through conventional treatments alone.
If a larger study shows similar effects, Yavagal foresees a time in the not-too-distant future when combining thrombectomy with stem cells “will give us an ability to turn stroke into something like a fracture, where we completely repair it.”
This isn’t the first time Miller School researchers have pioneered advancements in stroke treatment.
Until recently, doctors relied on delivering the clot-busting drug tPA through a vein to reopen a stroke patient’s clogged vessels and get blood flowing in the brain. As the minutes ticked by before the drug took effect, however, brain cells continued to die.
“We would have all these paralyzed patients who we really couldn’t do anything for, except send them to rehab,” said Yavagal.
Today, using the drug in combination with a catheter-based system for clearing the blockage — mechanical thrombectomy, a treatment method the Miller School helped to pioneer — has recently become the international standard of care.
“Mechanical thrombectomy completely changed the treatment of stroke,” said Yavagal. “As many as seven out of 10 people could be walking out if they all came in within six hours of the start of their stroke symptoms. We’re seeing that on a daily basis now.”