Abstract: The invention concerns a device partly occluding a vessel, of the type comprising a clip provided with teeth and designed to externally straddle the vessel. In the invention, the clip teeth are retractable, consisting notably of one or more flexible membranes which can be pressurized to array the teeth in projection in the active position or on the contrary which can be depressurized to withdraw the teeth and to put them in the passive position; the clip is associated with remote controls 2, 3 whereby the teeth can be put either into the active or into the passive position. These controls consist in particular of a catheter 3 and a hydraulic member pressurizing or depressurizing the clip membranes.