The role of D-dimer and fibrinogen testing in catheter-directed thrombolysis with urokinase for deep venous thrombosis.

Background: During catheter-directed thrombolysis (CDT), D-dimer (D-D) are generated in large quantities and fibrinogen (FIB) is continuously consumed. Reduction of FIB increases the risk of bleeding. However, there are currently few studies on the relationship between D-D and FIB concentrations during CDT.

Objectives: To evaluate the relationship of D-D and FIB concentrations during CDT with urokinase for deep venous thrombosis (DVT).

Method: 17 patients with lower limb DVT were enrolled and treated with CDT. The concentrations of plasma D-D and FIB were measured every 8 h during thrombolysis. The degree of thrombolysis was evaluated, the change rules of D-D and FIB concentrations were analyzed, and the change curve graphs were drawn. The "thrombus volume," "thrombolysis time," "thrombolysis ratio," "D-D peak," "D-D rising speed," "FIB falling speed," and "duration of D-D elevation" were calculated in each patient. The mixed model was used to simulate the time change trend of the plasma D-D and FIB concentrations. Pearson method and linear regression were used to analyze the correlation and linear relationship, respectively.

Results: The D-D concentration first increased rapidly and then decreased gradually, and the FIB concentration continued to decrease during thrombolysis. The rate of the decline of FIB varies with the urokinase dose. The thrombus volume is positively correlated with D-D rising speed, duration of D-D elevation, D-D peak, and FIB falling speed; the D-D rising speed is positively correlated with the D-D peak and FIB falling speed; and the D-D peak is positively correlated with the FIB falling speed. The correlation coefficients were all statistically significant (p < 0.05). Efficacy reached level I-II in 76.5% patients. No major bleeding occurred in any of the patients.

Conclusion: During CDT with urokinase for DVT, the concentrations of D-D and FIB show specific changes, and there are some specific relationships between each other. Understanding these changes and relationships may be helpful to adjust the thrombolysis time and urokinase dose more rationally.