f Dr. Dalyai | Neurosurgeon
STROKE PROGRAM

Stroke:

A stroke happens when a clot interrupts blood supply to an area of the brain or when a blood vessel, aneurysm or AVM in the brain ruptures leaking blood into the spaces surrounding brain tissue. Brain cells die when they no longer receive oxygen and nutrients from the blood or there is sudden bleeding into or around the brain.


The symptoms of a stroke include:

  • Sudden numbness or weakness on one side of the body or face
  • Sudden confusion or trouble speaking or understanding speech
  • Sudden trouble seeing in one or both eyes
  • Sudden trouble with walking, dizziness, or loss of balance or coordination
  • Sudden severe headache

The two types of stroke are ischemic (blockage of a blood vessel supplying the brain) and hemorrhagic (bleeding into or around the brain).

Stroke Prevention

Around 80 percent of all strokes are preventable. Changing, treating or controlling risk factors such as high blood pressure, cigarette smoking, irregular heart beat and physical inactivity, can greatly diminish the chances of having a stroke.

Additionally, when the great vessels in the neck show plaque buildup or blockage, surgical procedures may be needed. Carotid Endarterectomy is a procedure in which blood vessel blockage (fatty plaque) is surgically removed from the carotid artery. For some patients with carotid artery stenosis, Carotid Artery Stenting can be used. In carotid artery stenting, we use balloon to widen the vessel and the place a stent in the vessel to keep it open.

Acute Ischemic Stroke Treatment

Despite these methods in preventing stroke each year, more than 690,000 Americans have strokes caused by blood clots blocking vessels in the brain. The standard acute treatment is a clot-dissolving drug called is tissue plasminogen activator (ivTPA) given though an IV in the arm. IvtPA works by dissolving the clot and improving blood flow to the part of the brain being deprived of blood flow. But ivTPA must be given intravenously within 4.5 hours to be effective, and for people with large clots it only works about a 1/3 of the time.

A groundbreaking surgical treatment for sudden ischemic strokes is endovascular thrombectomy. With this procedure, Neurosurgeons can thread a catheter through an artery in the upper leg to the larger vessels in the brain. We can then remove a large clot by sending a wired-caged device called a stent retriever, to the site of the blocked blood vessel in the brain. When the stent opens it grabs the clot, allowing us to remove the stent with the trapped clot together. Recently the American Heart Association gave its strongest recommendation after a string of recent studies found they improve the odds that certain patients will survive and function normally again.

For some patients, the results are dramatic. However, this is a time-sensitive treatment that relies on people calling 911 as soon as they notice facial drooping, arm weakness or speech difficulty, some of the telltale warning signs of stroke. A significant number of stroke victims don’t get to the hospital in time for tPA or endovascular treatment; which is why it’s important to identify a stroke immediately.

Stent Retriever Mechanical Thrombectomy

Stroke Studies:

There were several new studies published in the New England Journal of Medicine in 2015 that confirmed that Endovascular thrombectomy was an effective treatment for acute ischemic stroke. In one study carried out in Canada, known as ESCAPE, they enrolled 315 qualified stroke patients. Most of the patients studied were given iv Tpa, and in addition about half of those patients were also treated with endovascular thrombectomy. The patients were followed clinically three months after their stroke and 53% of patients treated with endovascular thrombectomy were functionally independent and carrying out their own activities of daily living compared with only 29 percent given ivTPA only. In terms of survival, in the endovascular thombectomy group, close to 90% were still alive after 3 months as opposed to 81 percent in the ivTPA only group.

Results were similar in EXTEND-IA which was a study conducted in Australia. 71% of stroke patients treated with endovascular thrombectomy were functionally independent after 3 months compared with 40% treated with only ivTPA.

In a third study SWIFT PRIME, 196 stroke patients were studied comparing the use of endovascular thrombectomy with a solitaire stent-retriever. 60% of patients given both ivTPA and mechanical thrombectomy achieved functional independence at 3 months in comparison to around 36% given ivTPA alone. SWIFT PRIME also found fewer deaths among patients who had their clots removed with mechanical thrombectomy in 9.2% compared to 12.4% in ivTPA only.

In all three studies, the clot was removed from the blocked artery within six to 12 hours after stroke symptoms started and all patients were found to have large vessel occlusions by vascular imaging prior to angiography.

Hemorrhagic Stroke Treatment

Endovascular procedures may be used to treat certain hemorrhagic strokes similar to the way the procedure is used for treating an ischemic stroke. These procedures are typically less invasive than surgical treatments, and involve the use of a catheter introduced through a major artery in the upper leg, then guided to the aneurysm or AVM that caused the hemorrhagic stroke. Neurosurgeons are then able to place agents such as platinum coils or a glue-like substance to obliterate the lesion.

Surgical Treatment

For other hemorrhagic stroke caused by a cerebral arteriovenous malformation or aneurysm, surgical treatment may be done to prevent further the bleeding. Certain cerebral AVMs can be surgically resected and some ruptured aneurysm may be surgically treated with a titanium clip placed at the base of the aneurysm to remove it from the circulation.

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