Simulation study of hemodynamic commonality of umbrella-shaped inferior vena cava filter using computational fluid dynamics

The inferior vena cava filter (IVCF) has been used in clinical practice for decades to prevent fatal pulmonary embolism. One of the most commonly used types of IVCFs features a conical umbrella-like design. The geometric similarity among these umbrella-shaped IVCFs suggests a potential commonality in their hemodynamic behavior. However, many previous studies have primarily analyzed the blood flow around a single umbrella-shaped IVCF, failing to capture the general hemodynamic characteristics of this filter type. This paper uses computational fluid dynamics to simulate the blood flow around five typical umbrella-shaped IVCFs, aiming to investigate their hemodynamic commonality. For all five IVCFs, prothrombotic stagnation zones are observed downstream of the filter head, extending nearly 12 times the diameter of the inferior vena cava (IVC). The “viscous block” effect of the filter wires accelerates blood flow within the conical region of the filter, enhancing the potential for clot capture and dissolution. The deployment of umbrella-shaped IVCF remarkably increases the wall shear stress (WSS) on the IVC wall, and the WSS on the filter wire continuously increases in the flow direction. Additionally, the viscous resistance of each umbrella-shaped IVCF contributes several times more to the total flow resistance than the pressure resistance. Our results suggest that alterations in the morphology of the filter wires of umbrella-shaped IVCFs significantly impact the flow resistance of the filter and the WSS distribution pattern of the IVC. These hemodynamic changes may lead to life-threatening conditions, such as IVC lesions, filter rupture, and displacement.