Highly Promising Improvements in Stroke Care
Current Research Studies Show Benefits of Thrombectomy
Jul 22, 2015
Four current stroke studies show the benefits of mechanical therapy in stroke – not only as regards increased quality of life for patients, but also in terms of cost efficiency. Furthermore, the time window for stroke treatment can be expanded with the aid of a combination of intravenous medications.
Until 2014, studies did not show any benefits of mechanical therapy for cases of stroke. This was most likely due to a lack of experience at the centers participating in clinical trials, the use of old thrombectomy devices, and unfavorable patient selection. The MR Clean1 (Multicenter Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands) study presented the first breakthrough and validated the use of mechanical thrombectomy for patients with acute ischemic stroke with large vessel occlusion in the anterior circulation.
A Broad Scientific Consensus
Since then, two further publications (Extend IA2 and ESCAPE3) as well as the interim results from the SWIFT PRIME4 study, have supported these positive results and were even stopped prematurely due to the positive interim analysis. In all three studies, death at 90 days was lower and chances of a good functional outcome almost doubled in patients that had received a combination of intravenous medication to dissolve the clot (IV tPA) and therapy via mechanical clot retrieval in comparison to patients who had only received medication.
Benefits for Both Patients and the Hospital
All four studies showed that the time window for stroke treatment could be expanded from 4.5 hours with IV tPA to 6 hours with mechanical therapy. The selection criteria in the ESCAPE study even included patients with an onset to treatment time of up to 12 hours after the start of the stroke.
In addition to the benefits as regards increased quality of life for the patients, mechanical therapy was also shown to be cost effective: the Royal Melbourne Hospital found that thrombectomy lowered overall medical costs by reducing the amount of days a patient spent in the hospital5. Bloomberg called this a “revolution under way in stroke care”6.
The Role of Imaging
Imaging plays a key role in patient selection. In the studies, collaterals and the size of the penumbra proved to be key predictors for good therapy outcome and are visualized using either CT or MR angiography, or using perfusion CT or MR. Ultimately, the mechanical intervention requires precise device guidance through imaging in the angio suite.