Endovenous treatment device with flexible guidewire element

An endovenous treatment device having a delivery system of at least one treatment dose, the delivery system comprises a wired treatment dose delivery element which is flexible, which has a distal end portion capable of being inserted, at least over part of its length, longitudinally into a vein, and which is adapted for delivery into the vein of at least one treatment dose in a region of the end of said distal end portion, the endovenous treatment device further comprising a drive system for driving of the wired treatment dose delivery element in at least a given first drive direction, a guide which is flexible over all or part of its length, which has a proximal end portion and a distal end portion, and which allows the wired treatment dose delivery element to be guided over a portion of its length with a proximal end portion and, at the opposite end, a distal end portion of the wired treatment dose delivery element, which are not guided by the guide, a holding system which is positioned at the distal end portion of the guide and enables the distal end portion of the guide to be temporarily held relative to the body of a patient, near an insertion zone of the wired treatment dose delivery element, and a lock which allows the proximal end portion of the guide to be locked axially relative to the drive system, at least in the first drive direction of the wired treatment dose delivery element, the wired treatment dose delivery element being slidable in the direction of its length relative to the guide, so as to allow insertion longitudinally into the vein of the distal end portion of the wired treatment dose delivery element over at least a portion of its length.