Abstract: Objective To assess the effectiveness of improving the filter retrieval rate by catheter-directed thrombolysis compared with systemic thrombolysis in patients presented with stent thrombosis after inferior vena cava filters implantation. Methods This was a prospective, randomized, parallel group, single-center clinical study conducted in Beijing Jishuitan Hospital. Sixty subjects implanted with OptEase retrievable filters due to deep venous thrombosis (DVT) secondary to traumatic lower limb fracture seen from February 2013 to August 2014 were enrolled in this study. All subjects were diagnosed with stent thrombosis at least 1.0 cm in diameter by infeior vena cava angiography or color Doppler ultrasound. Subjects were randomized to receive catheter-directed thrombolysis or peripheral intravenous thrombolysis for six days. The primary study endpoint was the filter retrieval rate. Results The filter retrieval rate was 80% (24/30) in catheter-directed thrombolysis group compared with 36.7% (11/30) in the control group, the difference was statistically significant (P<0.05). The efficacy of thrombolysis was superior in the catheter-direct thrombolysis group based on the change of the size of thrombus after treatment compared to the baseline (P<0.05). No subjects experienced pulmonary embolism in follow-up period. Conclusion Compared with systemic thrombolysis, catheter-directed thrombolysis provided better efficacy in terms of increasing the rate of filter retrieval after stent obstruction.

Key words: deep venous thrombosis, inferior vena caval filter, thrombolysis, urokinase