Influence of a Commercial Antithrombotic Filter on the Caval Blood Flow During Neutra and Valsalva Maneuver

Abstract

Anticoagulants are the treatment of choice for pulmonary embolism. When these fail or are contraindicated, vena cava filters are effective devices for preventing clots from the legs from migrating to the lung. Many uncertainties exist when a filter is inserted, especially during physiological activity such as normal breathing and the Valsalva maneuver. These activities are often connected with filter migration and vena cava damage due to the various related vein geometrical configurations. In this work, we analyzed the response of the vena cava during normal breathing and Valsalva maneuver, for a healthy vena cava and after insertion of a commercial Günther-Tulip® filter. Validated computational fluid dynamics (CFD) and patient specific data are used for analyzing blood flow inside the vena cava during these maneuvers. While during normal breathing, the vena cava flow can be considered almost stationary with a very low pressure gradient, during Valsalva the extravascular pressure compresses the vena cava resulting in a drastic reduction of the vein section, a global flow decrease through the cava but increasing the velocity magnitude. This change in the section is altered by the presence of the filter which forces the section of the vena cava before the renal veins to keep open. The effect of the presence of the filter is investigated during these maneuvers showing changes in wall shear stress and velocity patterns.

The Effect of an Implanted Filter on Valsalva-Compression and Respiratory-Compression of the Inferior Vena Cava

“…We first simulate the Valsalva compression of an IVC with and without a Celect filter by applying a pressure difference across the wall of a vein with an elliptical cross-section when there is no filter present. We find that the resulting shape of the IVC with the filter during Valsalva is not in accord with observations of Laborda et al [16] and Nicolás et al [34].…”

“…We note that there have been previous simulations of the interaction of a filter with patient specific IVCs [16,34,35]. Laborda et al [16] and Nicolás et al [34] model the shape of the IVC from patient specific computed tomography data during normal breathing and Valsalva with and without an implanted filter.…”

“…We note that there have been previous simulations of the interaction of a filter with patient specific IVCs [16,34,35]. Laborda et al [16] and Nicolás et al [34] model the shape of the IVC from patient specific computed tomography data during normal breathing and Valsalva with and without an implanted filter. However, the geometric model of the IVC for each case is invariant and utilized as the boundary of a finite element mesh used for computational hemodynamics.…”

Calibration of interface properties and application to a finite element model for predicting vena cava filter–induced vein wall failure

“…Furthermore, most of these works are related only to clinical results or fluid analyses, without addressing the improvement of filter design. While there have been several hemodynamic studies of IVC filters, fewer have been published on the mechanical interaction between the vena cava and metallic filter …”

“…Furthermore, most of these works are related only to clinical results or fluid analyses, without addressing the improvement of filter design. While there have been several hemodynamic studies of IVC filters, 4,[19][20][21][22][23][24][25][26][27] fewer have been published on the mechanical interaction between the vena cava and metallic filter. [28][29][30] Analysis of other aspects of filter design such as strut perforation or filter migration are needed to evaluate the effectiveness of filters and develop new device models.…”