Influence of vascular embolism level and drug injection rate on thrombolytic therapy of bifurcated femoral vein: Numerical simulation and validation study

Background and objective: Deep vein thrombosis (DVT) of the lower limbs is a critical global vascular disease. Accurately assessing and predicting the efficacy of DVT treatment remains a significant challenge due to a lack of understanding of the mechanisms by which the level of patient-specific embolization and the rate of drug injection affect thrombolytic therapy.

Methods: In this study, we used the computed tomographic venography (CTV) clinical method to obtain patient-specific parameters, and the flow-solid interaction (FSI) method combined with biochemical response modeling of thrombolysis to analyze patient-specific hemodynamic and biomechanical characteristics and to quantitatively assess the effects of three vessel embolism levels (VEL) versus two drug injection rates (DIR) on bifurcated femoral venous thrombolytic therapy. In addition, we verified the reliability of the simulation results by in vitro thrombolytic therapy experiments.

Results: In the bifurcated femoral vein, the state of blood flow, vortex, wall shear stress (WSS), time-averaged wall shear stress (TAWSS), vessel wall pressure, leaflet motion displacement, and valve von Mises stress vary with thrombus size and vessel shape. Venous valves accelerate blood flow, producing a jet phenomenon. From the numerical and experimental results, thrombolytic therapy should select the injection rate according to the severity of the thrombus. Rapid injection restores flow in mild thrombosis, while slow injection ensures gradual drug penetration for serious thrombosis.

Conclusions: The present study found that the hemodynamic parameters and biomechanical characteristics explored are closely related to the efficacy of thrombolytic therapy. Both hemodynamic parameters and biomechanical characteristics are affected by blood flow velocity. At the same time, the study also revealed the mechanism of the influence of VTE and DIR on bifurcated venous thrombolytic therapy, to provide a scientific basis for clinicians to formulate more precise treatment strategies.