Abstract TMP110: A Novel Model of Ischemia in Rats With Middle Cerebral Artery Occlusion Using a Radiopaque Blood Clot and a Microcatheter Under Fluoroscopy

Abstract

Introduction: Conventional thromboembolic stroke model requires ligation of the ECA, which is problematic for research of thrombolytic agents because cerebral blood flow is different from human stroke. We aimed to develop a novel thromboembolic stroke model that does not require arterial ligation, using a radiopaque blood clot and microcatheter. Methods: Using male Sprague Dawley rats (n=14) and two sham operated rats were included, a microcatheter (inner diameter, 0.42mm; outer diameter, 0.55mm) was navigated from the caudal ventral artery to the left ICA using fluoroscopy. A blood clot (0.86 mm in diameter, 3 mm in length) containing zirconium dioxide was advanced in the catheter by injection of physiological saline to establish local occlusion. Both fluoroscopy at 1, 3, 6, 24 h and TTC staining at 24 h after stroke model creation were performed. Neurological deficit score was measured. Results: The success rate in selectively embolized of ACA and MCA bifurcation was 93% (13 of 14 cases). The median operating time was 7 min (interquartile range; 4-15 min). The median infarct volume (mm 3 ) was 248 (interquartile range; 239-280) 24 h after occlusion. Neurological deficit scores before and at 1, 3, 6, and 24 h after model creation differed significantly ( P < 0.001). Fluoroscopy showed the position of the radiopaque blood clot remains the same for 24 h after creating the model in 12 of 13 cases (92%). Sham-operated rats revealed no infarction and no neurological deficit. Conclusions: We present a novel rat model for focal infarct only in the MCA territory using a radiopaque blood clot. Fluoroscopy was able to identify whether the blood clot could migrate and recanalize.