Selective MCA occlusion: A precise embolic stroke model

The present study describes a method for improving the precision and accuracy of clot placement within the middle cerebral artery (MCA) of rats, utilizing a micro-catheter and laser Doppler flowmetry. This technique reduces the size of clot needed to achieve stable occlusion with no failed embolizations and a low percentage of early recanalizations. Infarctions were consistent in both size and distribution within the MCA perfusion territory. Selective embolization in aged animals (n= 10) resulted in substantially larger infarctions than those seen in aged animals (n= 10) following non-selective ernbolization (P < 0.05), or young animals (n= 10) subjected to filamentous occlusion (P < 0.001). Clots were localized to the MCA by direct examination at 0, 60 and 120 min post-embolization (n = 14). All aged animals surviving 24 h exhibited moderate to severe functional deficits, with selectively occluded animals having a higher mean score on the modified neurologic severity scale (P=0.002). This model provides a highly reproducible method for embolization of the MCA and reliable reperfusion with rt-PA. (c) 2006 Elsevier B.V. All rights reserved.