Evaluation of migration forces of a retrievable filter: Experimental setup and finite element study

The aim of this paper is to provide a computational study of migration forces of a retrievable filter (Günther Tulip inferior vena cava filter). Using an experimental setup and finite element simulation, the migration forces and stress at the end of the anchored hooks in the struts were estimated. After that, the estimation value of migration stress (τrup) was used to analyze the effect of different mechanical factors (strut thickness, vena cava diameter) in the migration of the IVC filter.Our results show that the migration stress is τrup = 4.37 N/mm2. Using this value we obtain that the filter with higher strut diameter (ϕstrut = 0.45 mm) shows the maximal migration forces in every cava diameter. On the other hand, the value of the migration force decreases when the cava diameter increases. In addition, the finite element simulations also show that there are contact between the struts of the filter and the vein in regions close to the anchors.