New stroke treatment extends window of opportunity
Research sponsored by the National Institutes of Health shows that about one in six Americans will experience a stroke at some point after age 65. Stroke is fatal in about 10 to 20 percent of cases and, among survivors, it can cause a host of disabilities including loss of mobility, impaired speech and cognitive problems. Although stroke is most common in older people, it can occur in individuals of any age, including young adults, children, infants and fetuses in the womb.
What the news
means to you
YNHH's Ketan Bulsara, MD, says timely recognition of symptoms remains the key.
A stroke is a sudden event affecting the brain's blood supply. In an ischemic stroke, a blood vessel that supplies the brain becomes blocked. In a hemorrhagic stroke, a blood vessel in the brain bursts.
Seeking emergency help immediately following a stroke can set in motion a series of life-saving events. Up until recently, three hours was thought to be the window of opportunity to initiate treatments to save brain cells from dying following an ischemic stroke. Only a small percentage of acute stroke patients come in to the hospital within the three-hour time window for effective treatment with tissue plasminogen activator (tPA), the FDA-approved clot-dissolving drug for ischemic stroke.
But when standard treatment with tPA fails to break up the clot, there is still hope. The FDA has approved two mechanical clot retrieval devices, the MERCI device and the Penumbra system. The latter was more recently approved. These devices have proved to be effective treatment options for patients up to eight hours after stroke symptoms onset..
In a multi-center trial of 125 patients presenting with acute ischemic stroke, a tiny catheter, which acts like a mini vacuum cleaner, was successful in removing blood clots blocking arteries in the brains of stroke patients 82 percent of the time. Called the Penumbra System, this treatment option is the newest device in the armamentarium to treat ischemic stroke.
What the news means to you
By Ketan R. Bulsara, MD
Advances in interventional technology have improved the outlook for patients who have suffered a stroke, but timely recognition of stroke symptoms are critical in order for successful treatment implementation.
A clot blocking the flow of blood to the brain represents a life-threatening emergency. The longer the blood flow is blocked, the greater the amount of brain that is injured... with devastating consequences. The recent studies with devices such as Penumbra show that a large proportion of blocked blood vessels can be re-opened, and if done within an eight hour window, good patient outcomes may be possible.
The Penumbra system represents the newest of the mechanical thrombolysis systems approved for use in the United States. The first step in treating a stroke with the Penumbra system is to localize the clot. To do this, cerebral angiography (brain catheterization) is used. A catheter is passed into a large artery in the groin. Using X-ray guidance and monitors, the catheter is threaded up through the carotid artery or vertebral artery to the brain. A dye called a contrast agent is injected into the carotid arteries. Using X-rays, the neurovascular surgeon can capture images of the dye flowing through the blood vessels.
When the clot is located, the Penumbra system is sent through the catheter to the blood clot. A device, called a separator, is used to dislodge the clot. A suction device then grabs the clot, thus removing it from the blood vessel.The treatment opens the blood vessel and restores blood flow to the brain.
Primary Stroke Centers are equipped to evaluate and treat patients who present with ischemic and hemorrhagic stroke. Larger, highly specialized hospitals such as Yale-New Haven Hospital, which are designated stroke centers, have access to the latest diagnostic and therapeutic developments in the field; and offer the widest range of interventional options to stop a stroke in progress and minimize the potential damage.
Dr. Bulsara is director of neuroendovascular and skull base surgery at Yale-New Haven Hospital and assistant professor of neurosurgery at Yale School of Medicine. He is part of a select group of neurosurgeons in the United States who is dual fellowship trained in cerebrovascular/skull base microsurgery and endovascular neurosurgery.
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