Potential New Approach to Stroke Treatment

Minimally invasive endovascular therapy is successful for over two-thirds of stroke patients treated outside the standard eight-hour window and could save thousands of lives, claims a new study.

Researchers at Massachusetts General Hospital - Harvard Medical School (Boston, USA) conducted a retrospective, multicenter study that included a consecutive case series of 237 patients whose first angiography confirming a clot in the brain was performed later than eight hours from the last time the patient was seen well. Of the 237 study participants, 49% were males and 51% were females (average age 64 years), whose mean time from "last seen well” to treatment was 15 hours. The participants registered a mean score of 15 on the U.S. standard National Institute of Health Stroke Scale (NIHSS)--a test that uses baseline data to determine severity of a stroke and projected outcome, and where any score over 10 is associated with a serious stroke. Various endovascular treatments were used, including: clot-dissolving drugs; the MERCI Retriever, a clot-removal device; and other mechanical instruments, including the Penumbra device.

The study findings showed that beyond the immediate results that showed an overwhelming success in restoring blood flow, follow-up at 90 days in 198 patients indicate that 47% of the patients registered good outcomes and 62% reflected acceptable outcomes. Approximately 9% suffered a symptomatic brain hemorrhage, and the overall mortality rate was 22%. When analyzing what factors were most closely associated with favorable outcomes, successful restoration of blood flow, younger age, lower stroke severity (as indicated by the NIHSS), and male gender were identified. In all, the results showed that endovascular therapy beyond the eight-hour window restored blood flow in the brain in approximately 74% of patients suffering ischemic stroke. The study was presented at the Society of Neuro Interventional Surgery (SNIS) sixth annual meeting, held during July 2009 in Boca Raton (FL, USA).

"We look forward to exploring this preliminary data more in-depth in order to bring more clarity to the treatment of late-presenting stroke patients,” said study presenter and lead author Raul Nogueira, M.D., an assistant professor in neurology and radiology. "The possibilities are exciting, as these findings could very well mean that thousands of patients who would not have been previous candidates for treatment could benefit from therapies that could restore their quality of life.”

When minimally invasive endovascular therapy made its debut two decades ago, stroke care underwent a major shift as the "window of treatment" for patients suffering a stroke was expanded to eight hours within symptom onset, rather than the standard three-hour window required by intravenous tissue plasminogen activator (tPA) therapy.

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Massachusetts General Hospital - Harvard Medical School