The present disclosure relates to permanently implantable electrode structures or probes of the type used, in particular, in cardiac pacemakers, ICDs, CRT-Ds and/or neurostimulators. Such electrode structures or probes include at least one control element, the physical-chemical state of which can be specifically manipulated using external excitation, such that local degradation or dissolution of a part of the implant or the entire implant takes place in this region. As a result of this partial dissolution, for example, the electrode structure or at least a portion thereof is modified such that the conditions for explantation are improved and/or parts of an implanted electrode structure that remain in the body are functionally deactivated.