Implantable endoluminal prosthesis (1) consisting of a braided framework (20) defining a cylindrical lumen (21) devoid of impermeable membrane, said braided framework (20) being self-expandable, comprising 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 (2) of given layers (22, 23, 24), the lattice defining polygonal opening units (26) when observed normal to a wall of the implantable endoluminal prosthesis (1), the diameter (Ø 25 ) of wire (25) being at least 50 µm and at most 150 µm, the maximal diameter (Ø 27 ) of the inscribed circle (27) of the polygonal opening units (26) being at least 75 µm and at most 200 µm in fully expanded state, wherein : €¢ The braided framework (20) consists of at least 128 and at most 512 wires (25)； €¢ the ratio (T 1 /Ø 25 ) of the thickness (T 1 ) of a wall of said implantable endoluminal prosthesis (1) to the diameter (Ø 25 ) of wire (25) is at least 5.5； €¢ in a fully expanded state, the surface coverage ratio (SCR) of said braided framework (20) is more than 50% and less than 90%； €¢ when the implantable endoluminal prosthesis (1) is deployed in a curved lumen having a H/W ratio between 0.5 and 0.9, the maximal diameter (Ø 27 ) of inscribed circle of opening units is at least 75 µm and at most 200 µm, the length-related compression ratio (LCR) being between 15% and 40%, and the surface coverage ratio (SCR) of the braided framework (20) being more than 50% at the side of outer curve.La présente invention concerne une prothèse endoluminale implantable pour prévenir un accident vasculaire cérébral. La prothèse endoluminale (1) consiste en une structure tressée (20) définissant une lumière cylindrique (21) dépourvue de membrane imperméable. Ladite structure tressée (20) est auto-dilatable, et comprend une pluralité de couches (22, 23, 24) de fils (25) fabriqués en un matér
