Abstract T P224: A Canine Model of Acute Segmental Vertebral Artery Embolism

BACKGROUND: Limited availability of suitable animal model of cerebrovascular thrombosis has hampered the study of mechanical thrombectomy and clot retrieval therapies. To facilitate endovascular interventional evaluations, this study aims to develop an animal model of acute occlusion in canine vertebral artery (VA). We developed a technique for site-specific placement of a thrombus in canine model for the purpose of evaluating methods of mechanical thrombectomy and clot retrieval that allows visualization of dislocation or fragmentation of the thrombus during angiographic manipulation. METHODS: Angiography and embolization with a preformed thrombus was performed in 6 canines. Bilateral femoral artery puncture were performed. Under fluoroscopic guidance, an embolism protection device (EPD) was anchored to the middle segment of the left vertebral artery via the left femoral arterial sheath. A preformed radiopaque clot was injected through the guide catheter into the left VA, via contralateral femoral artery, proximal to the EPD. After 15 min of occlusion, the EPD was removed and persistent occlusion of the VA was documented angiographically. RESULTS: Angiography performed during the observation period confirmed persistence of VA occlusion in each case. Each VA was occluded angiographically and radiopaque clots were not found displaced during the 3-hour observation period. The setting allowed selective embolization of targeted vessels without thrombus fragmentation. Recanalization to the occluded artery was not observed in all of the arteries. Histologic evaluation revealed no intimal damage caused by the thrombus or contrast agent washout. CONCLUSION: We demonstrated, for the first time, a canine model of post circulation embolism induced by the autologous blood clot placement. This model can be rapidly formed, easily operated, and site controlled. This new technique may be beneficial for preclinical evaluation of thrombectomy devices in acute cerebrovascular stroke.