Movie buffs may recall the plot of the 1966 film Fantastic Voyage — a team of doctors in a submarine is shrunk to microscopic size and injected into a man’s bloodstream on a mission to repair brain damage.
These days, shrinkage is not necessary, as specialists called interventional radiologists perfect techniques to treat medical emergencies with a catheter threaded through the body’s arteries.
Treatment shown to be effective
This approach now helps stroke patients, as brain stents inserted through arteries are increasingly used to retrieve blood clots. Though a large 2013 study cast doubt that this treatment was effective, recent research by UC Irvine Health physician Dr. Shuichi Suzuki showed that such tools work, especially when combined with the clot-busting drug tPA.
Suzuki’s findings are consistent with those of several studies presented at the February International Stroke Conference in Nashville.
The UC Irvine Health study documented the results of the 63 patients Suzuki and the UC Irvine stroke team treated between March 2012 and October 2014, using a brain stent clot retriever device. In 39 of the cases, patients were treated with a combination of tPA and the brain stent. Patients ranged in age from 24 to 86, included 32 men and 31 women, and all were experiencing a moderate to severe ischemic stroke. An ischemic stroke is triggered by a blood clot.
Individual evaluations were conducted three to 12 months after intervention and measured according to the modified Rankin Scale, the most widely used for assessing the degree of disability in stroke patients. Almost half of the patients — 42 percent — were able to resume their normal activities without assistance, with another 18 percent showing only moderate symptoms.
Time of the essence
“Restoring blood flow in a timely and effective manner to damaged tissue is critical, because 1.9 million brain cells per minute die when blood flow is obstructed,” Suzuki said. “If not fatal, this type of stroke often leads to profound physical disability. Our study results represent a great advance in interventional stroke care. Acute patients treated with the brain stent clot retriever are far more likely to be alive and able to live independently.”
However, none of these treatments are effective unless a patient gets help quickly. Suzuki says that the chance of survival or survival without major disability drops dramatically hours after symptoms appear.
For tPA to be effective, it must be administered within three hours after the onset of symptoms, while the brain stent procedure can be performed as long as six hours after symptom onset.
“Many patients are not eligible for tPA at their time of presentation, due to other pre-existing medical conditions, if they’ve had recent surgery or are taking blood thinner medications, “ Suzuki said. “Also, while tPA is effective for dissolving small clots and has saved many lives, large clots, which are more devastating, do not respond as well. The stent clot retrieval procedure is safe, quickly restores blood flow and expands the window of treatment time to six hours. Most importantly, patient outcomes were much better.”