Evaluation of hemodynamic effects of different inferior vena cava filter heads using computational fluid dynamics

Abstract

Inferior vena cava (IVC) filters are used to prevent pulmonary embolism in patients with deep vein thrombosis for whom anticoagulation is unresponsive. The head is a necessary structure for an Inferior vena cava filter (IVCF) in clinic use. At present, there are various head configurations for IVCFs. However, the effect of head pattern on the hemodynamics of IVCF is still a matter of unclear. In this study, computational fluid dynamics is used to simulate non-Newtonian blood flows around four IVCFs with different heads inside an IVC model, in which the Denali filter with a solid and hooked head is employed as a prototype, and three virtual variants are reconstructed either with a no-hook head or with a through-hole head for comparison. The simulation results show that the through-hole head can effectively avoid the recirculation region and weaken the blood flow stasis closely downstream the IVCF head. The shape change of the filter head has no significant effect on the blood flow acceleration inside the IVCF cone as well as little influence on the wall shear stress (WSS) distribution on the filter wire surface and IVC wall. The structure pattern of filter head greatly affects the flow resistance of its own. However, the flow drag of filter head only occupies a small proportion of the total resistance of IVCF. Therefore, to reduce the flow resistance of an IVCF should optimize its whole structure.

CFD Study on Hemodynamic Characteristics of Inferior Vena Cava Filter Affected by Blood Vessel Diameter

“…Therefore, in this study, in vitro measurements of the TrapEase filter in a rigid, homogeneous circular tubular IVC model derived from the study of Leask et al were used to validate the accuracy of the numerical simulations in this paper [27]. The reliability of the CFD method used in this paper has been confirmed by our previous studies [30]. The results showed that the simulated data were in high agreement with the experimental data, with an overall average deviation within 15%.…”

“…Compared to arteries, clinical observations show less pulsatility and pressure of IVC blood flow [10], therefore, the flow in the IVC was assumed to be constant flow [29,30] and the corresponding governing equation was the three-dimensional constant viscous incompressible Navier-Stokes equation of the following form [10,35]:…”

“…This study focused on the effect of vessel diameter variation on filter hemodynamics, temporarily ignoring some complex physiological factors, such as iliac and renal veins, and the IVC contractile deformation [28]. It was assumed that the IVC was a rigid straight tube with uniform wall thickness and a circular cross-section [20,29,30]. The filter was implanted normally into the IVC without considering undesirable conditions such as tilting and displacement of the filter.…”

Optimizing inferior vena cava filter design: A computational fluid dynamics study on strut configuration for enhanced hemodynamic performance and thrombosis reduction

“…The black dotted line in Fig. 9 (a) is the line where the blood flow that enters the filter interior first meets the struts and the stagnant and recirculating areas of the fully developed head region are clearly divided due to the viscous block effect [ 39 , 40 ]. This dotted line develops downwards to the inlet side (upstream of the filter) as the arm length increases.…”

Numerical simulation and in vitro experimental study of the hemodynamic performance of vena cava filters with helical forms

“…IVCF implantation also needs to consider its ability to capture thrombi and dissolve the captured thrombi immediately, as well as the risk of IVCF displacement [14]. The performance of IVCF is closely related to hemodynamic factors [15]. Many researchers have performed numerical simulations and in vitro experiments to evaluate the culture and dissolution effects of IVCF.…”