Stent Retrievers Recommended in Stroke Guide

Stent retriever thrombectomy should be performed for selected stroke patients at specialized centers after tissue plasminogen activator (tPA), the American Heart Association/American Stroke Association recommended.

That focused update to 2013 guidelines, published online in Stroke, included acute ischemic stroke patients meeting all of the following criteria:

• Prestroke modified Rankin Scale score 0 to 1
• IV tPA given within 4.5 hours of onset
• Causative occlusion of the internal carotid artery or proximal middle cerebral artery (M1)
• National Institutes of Health Stroke Scale (NIHSS) score of 6 or higher
• Alberta Stroke Program Early CT score (ASPECTS) of at least 6
• Groin puncture for endovascular treatment feasible within 6 hours of symptom onset

"Use of stent retrievers is indicated in preference to the MERCI device," the update noted, also with a Class I, level of Evidence A recommendation.

The update came as no surprise to J Mocco, MD, director of the Cerebrovascular Center at Mount Sinai Health System in New York City.

“These guidelines reflect the recent avalanche of positive trials demonstrating the overwhelming benefit of removing clots from clogged brain arteries for patients that are suffering from stroke,” he told MedPage Today in an email. “There have been many of us who have long believed in the benefit of this approach, but the positive data published over the past year have now convinced the larger community of the importance of this approach.”

William J. Powers, MD, of the University of North Carolina at Chapel Hill, and colleagues analyzed results from eight randomized clinical trials of endovascular treatment published since 2013 as "pivotal new evidence that justifies changes in current recommendations."

The first three were done primarily with intra-arterial fibrinolysis and first generation thrombectomy devices without showing any advantage either as a substitute for tPA or subsequent to it.

The latest five -- MR CLEAN, EXTEND-IA, ESCAPE, SWIFT-PRIME, and REVASCAT -- almost exclusively used stent retrievers with uniformly higher recanalization rates and benefits in functional outcome compared with thrombolysis or usual care alone.

While two of those allowed salvage intra-arterial fibrinolysis, the data wasn't sufficient to say more than it "may be reasonable to employ in some clinical circumstances," the guideline noted.

Although the time window for enrollment in the positive trials varied, the recommendations settled on 6 hours as the best supported thrombectomy window. Beyond that point, the guidelines didn't say endovascular treatment is pointless but did note that its effectiveness is "uncertain."

Likewise, for other criteria outside the recommended set, such as mechanical clot removal in strokes from occlusion of the M2 or M3 or in people under age 18, the updated guide suggested treatment could be appropriate in carefully selected individuals.

The data wasn't definitive on anesthesia use, but the guide concluded: "On balance, data from published data broadly indicate that conscious sedation might be safer and more effective than general anesthesia in the setting of endovascular therapy for acute ischemic stroke."

The guidelines still recommended transport of patients to the closest certified primary stroke center or comprehensive stroke center, but now also argued for regional systems of care to be organized around endovascular treatment as well.

"This additional treatment is more difficult than tPA, which can be given by most doctors in the emergency room," Powers said in a press release.

The update was endorsed by the American Association of Neurological Surgeons, Congress of Neurological Surgeons, American Society of Neuroradiology, and Society of Vascular and Interventional Neurology, while the American Academy of Neurology "affirms the value" as an educational tool.

From the American Heart Association:

• AHA Emerging Science Series Webinar - 2015 Updated Guidelines for Endovascular Treatment of Patients with Acute Ischemic Stroke
• 2015 AHA/ASA Focused Update of the 2013 Guidelines for the Early Management of Patients With Acute Ischemic Stroke Regarding Endovascular Treatment

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