NEW THROMBOLYTIC BRUSH CATHETER IN THROMBOSED POLYTETRAFLUOROETHYLENEDIALYSIS GRAFTS - PRECLINICAL ANIMAL STUDY

PURPOSE: To assess the safety, efficacy, endothelial changes, and risk s of pulmonary embolic events after the use of a mew thrombolytic brus h catheter in mature thrombosed polytetrafluoroethylene (PTFE) dialysi s grafts in an animal model. MATERIALS AND METHODS: Loop configuration PTFE grafts were implanted in the femoral vessels of 12 canines 4 wee ks before mechanical thrombosis was performed. The thrombus was allowe d to consolidate for 24 hours in 10 animals, 72 hours in one animal, a nd 7 days in one animal, Standard percutaneous criss-cross catheter ac cess was performed, and a soft, low-speed, brush (6 mm in diameter), a ided by 250,000 U of periprocedural urokinase, was utilized for thromb olysis. The native vessels, just distal to the anastomosis, and lungs were evaluated macro- and microscopically, RESULTS: Thrombolysis was c omplete in all grafts with the exception of a small segment between th e crossing of the access vascular sheaths. The total thrombolysis time ranged from 8 to 12 minutes; this included 5 minutes of pulse-spray l acing, No difference in thrombolysis time was found with regard to the age or amount of thrombus, Minimal endothelial changes were noted and no evidence of acute pulmonary embolus was found on necropsy or histo logic studies, CONCLUSION: This method offers a simple, safe, and effi cient means of recanalization of thrombosed PTFE dialysis grafts in th is canine model.