Vascular protection system comprising a radially expandable filtering element (10) permeable to blood but impermeable to embolic materials, comprising a membrane (9) linked to a hollow support structure made up of a succession of wires (70₁, 70₂). The support structure comprises at least two groups (34, 36) of wires, each having more than two mutually adjacent wires, these groups being parted at a point on the length of the wires so that at least some of the wires within one of the groups part from one another, after which, farther along this length, the wires of a specific group which part from at least some of the other wires of this same group rejoin at least one wire of (one of) the other group(s) of wires.