The invention discloses a
vena cava filter which is placed at the position of an
inferior vena cava between
kidney venas and iliac venas, and is formed by integrally
cutting a
nickel-
titanium alloy pipe with
laser. The filter comprises connecting rods, a top layer filter screen, a middle layer filter screen and a bottom layer filter screen, wherein the top layer filter screen, the middle layer filter screen and the bottom layer filter screen are jointly formed in a cage-shaped structure, the middle layer filter screen is positioned between the top layer filter screen and the bottom layer filter screen, and is formed by inwards bending a plurality of branches which are
cut; the top layer filter screen and the middle layer filter screen can capture and intercept larger
thrombosis, and the bottom layer filter screen can capture and intercept smaller
thrombosis; the surfaces of the filter screens of the three
layers are wrapped with PTFE (
poly tetra fluoro ethylene) films; the connecting rods are in contact with vascular walls, are connected with the cage-shaped structure, can be divided into more than two branches, are formed by expanding, and are wrapped with the PTFE films. The
vena cava filter provided by the invention has the advantages that the effect of filtering the
thrombosis is excellent, the
vena cava filter can be repeatedly and firmly positioned, the
implantation time can be prolonged, the vena cava filter can be recovered, and the endothelialization effect can be delayed.