Recanalization of thrombosed superficial femoral arteries with a hydraulicthrombectomy catheter in a canine model

OBJECTIVE. This experiment was conducted to evaluate efficacy and safety of the Oasis thrombectomy catheter on arterial thrombosis in dogs. MATERIALS AND METHODS. Thrombosis was induced in 18 femoral arteries of nin e mongrel dogs. Recanalization of the thrombosed femoral artery was perform ed using a thrombectomy catheter 7-10 days after thrombus induction. Pre- a nd postprocedural arterial status was documented by angiography. After mech anical thrombectomy, the animals were sacrificed and the femoral arteries w ere harvested and examined macro- and microscopically. Additionally, in vit ro fragmentation was carried out to determine particle size and distributio n from the recovered effluent. RESULTS. Subacute thrombosis was successfully created in 15 femoral arterie s. Full recanalization was achieved in 80% (12/15) of the thrombosed femora l arteries without any residual thrombus. No significant downstream emboliz ation was documented angiographically. Endothelial denudation was observed in all the treated arteries along with occasional disruption of the interna l elastic lamina. No medial injury was seen. Ninety-eight percent of thromb us was liquefied, defined as particles smaller than 15 mu m, by the cathete r. Particles larger than 400 mu m represented 0.27% of the original clot we ight. CONCLUSION. Occluded femoral arteries with 7- to 10-day-old thrombus can be efficiently recanalized with the Oasis catheter in dogs without any signif icant complication. This thrombectomy catheter appears to be highly effecti ve and safe and requires no sophisticated equipment. Blood loss was our maj or concern regarding use of this catheter but can be minimized by strictly controlling activation time and restricting the inflow into the vascular se gment being treated.