[Hemodynamic analysis of a new retrievable vena cava filter]

Area of Science:

• Biomedical Engineering
• Cardiovascular Devices
• Fluid Dynamics

Background:

• Pulmonary embolism (PE) is a life-threatening condition often caused by detached thrombi from lower limbs and pelvis.
• Vena cava filters are crucial devices for preventing PE by trapping thrombi.
• Existing filters like Denali and Aegisy have limitations in hemodynamic performance and thrombus capture efficiency.

Purpose of the Study:

• To design and evaluate a novel retrievable vena cava filter.
• To assess the hemodynamic performance and thrombus capture efficiency of the new filter.
• To compare the new filter against commercial Denali and Aegisy filters using computational fluid dynamics (CFD) and in vitro experiments.

Main Methods:

• Utilized computational fluid dynamics (CFD) with a two-phase flow model to simulate hemodynamics.
• Analyzed parameters including blood flow velocity, pressure difference, and wall shear stress.
• Conducted in vitro experiments to evaluate thrombus capture efficiency for various thrombus sizes (5-15 mm) and concentrations (10-30%).

Main Results:

• The Denali filter showed minimal blood flow interference but poor capture of small thrombi.
• The Aegisy filter exhibited excellent thrombus trapping but had the largest low wall shear stress area, increasing thrombosis risk.
• The newly designed filter demonstrated effective capture of small-diameter thrombi and a smaller low wall shear stress area, reducing thrombosis risk.

Conclusions:

• The novel retrievable vena cava filter offers superior thrombus capture efficiency, particularly for small thrombi.
• The new filter design minimizes areas of low wall shear stress, thereby reducing the risk of secondary thrombosis.
• This new filter design provides a valuable reference for future development and clinical selection of vena cava filters.