An electrostimulator implant is percutaneously advanceable into tissue of a limb of a subject. The implant comprises (i) an intracorporeal sensor, configured to detect a factor indicative of local blood supply in the tissue of the limb; (ii) an electrode disposed at an outer surface of the implant; (iii) an antenna, configured to wirelessly receive power; and (iv) circuitry, powered by the received power, and configured to drive the electrode to apply a bloodflow-increasing current to the tissue at least in part responsively to the detected factor. Other embodiments are also described.