An implantable permanent filter assembly (1) for deployment in a bifurcated vessel comprises a main vessel and at least two branches. This assembly comprises a filtering sleeve (2) formed of an expendable braided framework (20) able to expand from a radially compressed state in a delivery configuration to a radially expanded state. The filtering sleeve extends along an axis and defines a cylindrical lumen devoid of impermeable layer, having a distal end configured to extend toward the branches of the bifurcated vessel and a proximal end configured to extend toward away from the branches of the bifurcated vessel. The braided framework has a plurality of layers (22,23,24) of wires (25) made of biocompatible material, each layer forming a mesh, the meshes forming a lattice with a plurality of wires of each layers. The lattice, when observed normal with respect to a wall of the implantable endoluminal prosthesis, defines polygonal openings, the diameter of the wire being at least 20 micrometres and at most 100 micrometres.
