An implantable medical lead has at least one electric conductor running along a lead body and electrically interconnecting at least one electrode at the distal portion of the lead with at least one lead terminal at the proximal portion of the lead. The lead also has at least one closed channel running along at least a portion of the lead body. The closed channel contains an extracorporeally detectable detection substance. A rupture to the lead will cause the detection substance to leak out of the channel and outside of the lead body. Lead damage can be confirmed by the absence of or a reduced amount of said detection substance inside the lead.