Mechanical Embolectomy for Treatment of Acute Stroke
DESCRIPTION
The majority of strokes are caused by emboli, and these frequently present as acute neurologic emergencies. The acute brain injury of stroke has two major types: hemorrhagic and ischemic. Approximately 80% of patients with stroke presenting to the emergency department will be diagnosed with ischemic brain injury. Distinguishing between these types of stroke is important because the established treatments for each are significantly different.
The focus of treatment in hemorrhagic stroke is correction of the condition which led to bleeding. The focus of ischemic stroke treatment is reperfusion of hypoxic brain tissue. If the underlying cause of ischemia is systemic hypotension, this must be corrected. Far more commonly, however, a clot occluding an intracranial vessel is the cause of ischemic stroke. Tissue plasminogen activator (tPA) given intravenously within 3 hours of symptom onset is approved by the U.S. Food and Drug Administration (FDA) for treatment of acute ischemic strokes to promote clot dissolution and subsequent restoration of blood flow to the ischemic area of the brain.
Mechanical embolectomy is being studied as another method of ischemic stroke treatment caused by a clot occluding an intracranial vessel. Clots can be defined as located in large or small vessels. Large intracranial arteries include the internal carotid, Circle of Willis and the first two branches of the anterior (A1 and A2), middle (M1 and M2), and posterior (P1 and P2) cerebral arteries and can be accessed with a catheter. Further branches of the cerebral circulation are defined as small vessels and are too tortuous to be accessed with available technology, thus mechanical embolectomy is being investigated for this use.
Examples of mechanical embolectomy devices are the Merci® Retriever and Penumbra System®. With the Merci® Receiver device, a microcatheter is passed through the thrombus from a larger, percutaneous catheter positioned proximal to the occlusion. A helical snare is deployed and the catheter and clot are withdrawn together. With the Penumbra System® device, an opening at the tip of the percutaneous catheter utilizes suction to extract the clot.
POLICY
Mechanical embolectomy for the treatment of acute stroke is considered investigational.
IMPORTANT REMINDER
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ADDITIONAL INFORMATION
There is a lack of well-designed studies to assess the impact of this treatment. The scientific evidence does not permit conclusions concerning the effect of mechanical embolectomy on individuals’ outcomes. The existing observational data are not sufficient to determine if this approach improves net health outcomes.
SOURCES
BlueCross BlueShield Association. Medical Policy Reference Manual. (9:2010). Mechanical embolectomy for treatment of acute stroke (2.01.76). Retrieved November 1, 2010 from BlueWeb. (19 articles and / or guidelines reviewed)
Novakovic, R., Toth, G., & Purdy, P. D. (2009). Review of current and emerging therapies in acute ischemic stroke. Journal of NeuroInterventional Surgery, 1 (13), 13-26.
Meyers, P. M., Schumacher, H. C., Higashida, R. T., Barnwell, S. L., Creager, M. A., Gupta, R., et al. (2009). Indications for the performance of intracranial endovascular neurointerventional procedures: A scientific statement from the American Heart Association Council on Cardiovascular Radiology and Intervention, Stroke Council, Council on Cardiovascular Surgery and Anesthesia, Interdisciplinary Council on Peripheral Vascular Disease, and Interdisciplinary Council on Quality of Care and Outcomes Research. Circulation, 119 (16), 2235-2249.
ORIGINAL EFFECTIVE DATE: 4/14/2011
MOST RECENT REVIEW DATE: 4/14/2011
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