Recanalization of an acute middle cerebral artery occlusion using a self-expanding, reconstrainable, intracranial microstent as a temporary endovascular bypass.

BACKGROUND AND PURPOSE Although self-expanding intracranial microstents have been used to treat acute middle cerebral artery (MCA) stroke, there are disadvantages associated with placing a permanent endovascular implant. We describe a technique in which a reconstrainable stent was used to provide a temporary endovascular bypass to achieve MCA recanalization without permanent stent implantation. METHODS A 55-year-old male presented with acute onset left hemiplegia (National Institutes of Health Stroke Score (NIHSS) of 20. Angiography showed an occluded right cervical internal carotid artery (ICA), a patent anterior communicating artery (ACOMM), and embolic occlusion of the right middle cerebral artery (MCA), M1 segment. RESULTS Working through a 6F guide-catheter positioned in the left cervical ICA, an SL-10 microcatheter, and 0.014-inch Synchro-2 microwire were manipulated across the anterior communicating artery and into the right M1 segment occlusion. 5 mg of abciximab and 3 mg tPA were infused directly into the thrombus through the microcatheter. Mechanical thrombolysis using the microwire and microcatheter was ineffective in achieving any recanalization. An Enterprise stent (4x22 mm) was delivered across the occlusion site and partially unconstrained. The unconstrained portion of the stent expanded and acted as a temporary bypass, to circumferentially displace and structurally disrupt the M1 thrombus, producing immediate revascularization of the right territory MCA. After approximately 20 minutes, the Enterprise stent was reconstrained and removed. Final angiography demonstrated excellent filling of the right M1 and distal MCA branches. The patient improved to an NIHSS of 7, regaining movement of his left upper and lower extremities. CONCLUSIONS The temporary endovascular bypass technique yielded immediate and durable revascularization of an acutely occluded middle cerebral artery without the disadvantages associated with the placement of a permanent endovascular stent.