Toward an Optimal Position for Inferior Vena Cava Filters: Computational Modeling of the Impact of Renal Vein Inflow with Celect and TrapEase Filters

Schematic diagram of the three-dimensional model showing the IVC, renal veins, and filter positions. Letters A–F correspond to positions of the downstream cone of the Celect and TrapEase filters. Positions A and B are infrarenal, C is just below juxtarenal position with the cone near the level of the renal vein inflow, D and E are juxtarenal, and F is suprarenal in position.

Models of the unoccluded TrapEase and Celect filters within the computational model of the IVC and renal veins. Filters are positioned at vena cava positions C and F in the schematic diagram in Figure 1. Note the regions of naturally occurring stagnant flow (arrows) along the bilateral vena cava walls just downstream of the renal venous inflow.

Normalized WSS profiles for the Celect filter in different IVC positions (see A–F in Fig 1) with a 1.0 mL spherical thrombus in the central downstream trapping position. Dotted line indicates Celect filter at position C without thrombus. Both sides of the vena cava wall are evaluated. Flow is from left to right, and the x-axis denotes the distance (in mm) from the downstream tip of the filter. Symmetry is observed in the Celect filter with low WSSs downstream of the thrombus and relatively high shear stresses with suprarenal placement (position F in Fig 1). Breaks in the WSS lines correspond with the locations of renal vein inflow where no wall is present.

Normalized WSS profiles for the TrapEase filter in different IVC positions (see A–F in Fig 1) with a 1.0 mL spherical thrombus in the central downstream trapping position (a) or a 0.5 mL spherical thrombus in the right lateral upstream trapping position (b). Dotted line indicates TrapEase filter at position C (see Fig 1) without thrombus. Both sides of the vena cava wall are evaluated. Flow is from left to right, and the x-axis denotes distance (in mm) from the downstream tip of the filter. Breaks in the lines of WSS correspond with the locations of renal vein inflow where no wall is present. (a) Symmetry is observed in the TrapEase filter with low WSSs downstream of the thrombus and relatively high shear stresses with suprarenal placement (position F in Fig 1). (b) At position F (red line), there is a decrease in the WSS along the right wall at approximately 50 mm proximal to the downstream tip of the filter, which is a result of the overlap between the stagnant/recirculating flow downstream of the renal vein inflow (from 55 mm to 60 mm upstream of the tip) and the flow disruption caused by the upstream, laterally trapped thrombus.

TrapEase filter at IVC positions A, C, and F (see Fig 1) with a 0.5 mL thrombus in the upstream trapping position (A1, C1, and F1) and a 1.0 mL thrombus in the downstream trapping position (A2, C2, and F2). Color scale corresponds with normalized velocities. For configurations F1 and F2, the arrows denote regions of naturally occurring stagnant/recirculating flow caused by renal inflow.

Flow past the Celect filter partially occluded with a 1.0-cm3 thrombus. The velocity color scale is normalized (to pipe flow), and all images have the same scale. The filters are positioned at IVC stations A–F (see Fig 1).