Local and systemic changes of fibrinolytic parameters in blood during catheter-directed intra-arterial thrombolysis

Fibrinolytic parameters (plasminogen, fibrinogen, alpha2-antiplasmin, euglobulin clot lysis time and D-dimers) were measured locally near the occlusive peripheral arterial thrombus and in systemic blood of 27 patients treated by catheter-directed thrombolysis with streptokinase. The parameters were measured simultaneously in systemic (venous) and in local (arterial) blood before and 0.5, 1.5, 4, 8, 24 and 48 h after the start of treatment with streptokinase (3750 IU/h). A time-dependent decrease in the concentrations of plasminogen, alpha2-antiplasmin and fibrinogen was measured in both arterial and venous blood, reaching: for plasminogen 39 and 47, for alpha2-antiplasmin 18 and 26, and for fibrinogen 50% and 61%, respectively, of the pretreatment values. A time-dependent increase in D-dimer levels and a shortening of euglobulin clot lysis time were also detected. The differences between time-related arterial and venous samples were significant at least for the first 24 h and became smaller after 48 h of treatment, when at least partial recanalization was achieved in the majority of patients. Our results show that the concentration of plasminogen is significantly reduced during catheter-directed thrombolysis in the systemic blood and even more in the blood surrounding the thrombus. This might reduce the efficacy of intra-arterial catheter-directed thrombolysis.