The invention relates to a safety cartridge (1) for a removable vena cava filter (20), having a proximal end (2) and a distal end (3) and having an inner channel (4) extending between the ends. The cartridge is characterized in that it comprises, on the distal end (3) thereof, a linking device (5) for forming a link with a catheter (30) and, in the inner channel thereof, a projection (6) having a limited size in the axial direction of the cartridge (1) so as to locally reduce the cross-section of the channel (4).