PURPOSE: To determine the experimental parameters in an in vitro model that influence the thrombus-capturing efficacy of the Vena Tech-LGM filter. MATERIALS AND METHODS: The Vena Tech-LGM filter was evaluated in an in vitro model of the vena cava with a computer-controlled flow system with a total of 5,200 thrombi. The influences of the following experimental parameters on the capture rate were analyzed with a multiple logistic regression model: type of testing (single, double, and multiple shot testing), thrombus diameter and length, IVC diameter and orientation, flow quality and quantity, flow velocity, and the length of the prepositioned thrombus. RESULTS: A significant influence on the capture rate could be demonstrated for the type of testing, the thrombus diameter and length, the IVC diameter, and with double shot testing for the length of the prepositioned thrombus and the IVC orientation. The flow quality and the peak velocity were not significant. Based on these results, a protocol for in vitro testing of IVC filters was designed. CONCLUSIONS: Experimental parameters influence the thrombus-capturing efficacy of the Vena Tech-LGM filter and should be taken into account when in vitro testing is performed.
PURPOSE: To determine the experimental parameters in an in vitro model that influence the thrombus-capturing efficacy of the Vena Tech-LGM filter. MATERIALS AND METHODS: The Vena Tech-LGM filter was evaluated in an in vitro model of the vena cava with a computer-controlled flow system with a total of 5,200 thrombi. The influences of the following experimental parameters on the capture rate were analyzed with a multiple logistic regression model: type of testing (single, double, and multiple shot testing), thrombus diameter and length, IVC diameter and orientation, flow quality and quantity, flow velocity, and the length of the prepositioned thrombus. RESULTS: A significant influence on the capture rate could be demonstrated for the type of testing, the thrombus diameter and length, the IVC diameter, and with double shot testing for the length of the prepositioned thrombus and the IVC orientation. The flow quality and the peak velocity were not significant. Based on these results, a protocol for in vitro testing of IVC filters was designed. CONCLUSIONS: Experimental parameters influence the thrombus-capturing efficacy of the Vena Tech-LGM filter and should be taken into account when in vitro testing is performed.
Authors: Ronald A Robinson; Luke H Herbertson; Srilekha Sarkar Das; Richard A Malinauskas; William F Pritchard; Laurence W Grossman Journal: Med Devices (Auckl) Date: 2013-05-10