Comparative evaluation of clinically available inferior vena cava filters with an in vitro physiologic simulation of the vena cava.
OBJECTIVE
A physiologic in vitro model of the human inferior vena cava (IVC) was developed to evaluate the clot-trapping efficiency of various IVC filters.


METHODS
The flow model closely simulates the physical parameters of the human IVC in fluid viscosity, specific gravity, temperature, and pulsatility; blood flow velocity, volume, and inherent turbulence; and vein orientation, wall compliance, and clot composition. Five filters--Greenfield (G), Bird's Nest (BN), Vena Tech (VT), Simon nitinol (SN), and titanium Greenfield (TG)--were compared by using two vena cava and blood clot sizes and horizontal and vertical orientation of the model.


RESULTS
Each filter varied significantly in its clot-capturing efficiency, depending on vena cava size and orientation and emboli size. Overall, decreasing rank order in filter clot-trapping efficiency was SN, BN, VT, TG, and G.


CONCLUSIONS
The in vitro model of the human IVC is an alternative to multicenter clinical trials in evaluating the relative clot-trapping efficiency of various IVC filters.
Simon
M
M
Department of Radiology, Harvard Thorndike Laboratory, Harvard Medical School, Beth Israel Hospital, Boston, MA 02215.
Rabkin
D J
DJ
Kleshinski
S
S
Kim
D
D
Ransil
B J
BJ
D004867:Equipment Design; D005069:Evaluation Studies as Topic; D006801:Humans; D008955:Models, Cardiovascular; D008961:Models, Structural; D011655:Pulmonary Embolism / Q000517:prevention & control*; D012039:Regional Blood Flow / Q000502:physiology; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior