Pharmacomechanical thrombolysis with use of the brush catheter in canine thrombosed femoropopliteal arterial PTFE bypass grafts

PURPOSE: To assess the efficacy, acute endothelial changes, and distal arterial emboli after use of the Cragg thrombolytic brush catheter in mature thrombosed polytetrafluoroethylene (PTFE) femoropopliteal arterial grafts in canines, MATERIALS AND METHODS: PTFE femoropopliteal arterial grafts were implanted in 10 canines and were allowed to mature for approximately 4 weeks, The grafts were thrombosed by mechanical means and allowed to remain thrombosed for 24-72 hours, Through a left carotid cut-down, standard Seldinger arterial puncture was performed, followed by catheterization of the thrombosed graft, A soft, low-speed, brush (6 mm in diameter) aided by preprocedure pulse-spray urokinase infusion was utilized for thrombolysis, The native vessels, just proximal and distal to the anastomosis, were evaluated microscopically for endothelial damage, Arteriography was used for assessment of distal embolus, RESULTS: All grafts were successfully thrombosed before thrombolysis, One graft could not be traversed with a wire and catheter and was, therefore, not treated, Immediate preprocedure pulse-spray urokinase infusion in the remaining nine grafts did not reconstitute antegrade flow in any instance and left significant amounts of residual thrombus in all treated grafts, Mechanical brush thrombolysis reconstituted antegrade flow in all nine treated grafts and complete graft thrombolysis was obtained in most, This was accomplished in a mean time of less than 4 minutes, Emboli were noted angiographically in 67% of cases, Histologic studies showed vessel wall damage limited to the intima or media in 67% of anastomoses. CONCLUSION: This method offers a simple and rapid means of recanalizing thrombosed PIPE femoropopliteal arterial grafts in the studied model, This technique provides a means of rapidly "debulking" most intragraft thrombi, This may result in a shorter course of thrombolytic infusion, Potential benefits may include shortening the total treatment time and decreasing morbidity and cost associated with percutaneous thrombolysis, The occurrence of distal emboli in a majority of cases is a concerning limitation of this technique.