An Endovascular Canine Middle Cerebral Artery Occlusion Model for the Study of Leptomeningeal Collateral Recruitment

Objectives: This work aimed to refine a large animal in minimally invasive reversible middle cerebral artery (MCA) occlusion (MCAO) model to account for leptomeningeal collateral formation. Materials and Methods: An angiographically based methodology allowed for transient MCA and carotid terminus occlusion in 12 mongrel dogs and assessment of pial collateral recruitment. Outcome measures included 1- and 24-hour magnetic resonance imaging-based infarct volume calculation, a behavioral scale and histopathologic sections. Results: MCAO succeeded in 8 of 12 dogs (67% efficiency). One-hour postreperfusion infarct volume predicted 24-hour postreperfusion infarct volume (r2 = 0.997, P < 0.0001). Pial collateral recruitment varied with time and reproducibly assessed predicted infarct volume on 1-hour postreperfusion mean diffusivity maps (P < 0.0001; r2 = 0.946) and 24-hour fluid-attenuated inversion recovery FLAIR magnetic resonance imaging (P = 0.0033; r2 = 0.961). The canine stroke scale score correlated with infarct volumes and pial collateral score. Conclusion: This canine MCAO model produces defined cerebral infarct lesions whose volumes correlate with leptomeningeal collateral formation and canine behavior.