Retrieval of material from vessel lumens can be improved by electrically enhancing attachment of the material to a medical device. The device can include an elongate core member having a distal portion configured to be intravascularly positioned at a treatment site within a blood vessel lumen, and an interventional element connected to the distal portion of the elongate core member. The interventional element includes a body that is expandable from a first configuration to a second configuration and an electrically conductive radiopaque marker coupled to the body. An electrically conductive lead has a distal portion electrically coupled to the radiopaque marker and a proximal portion configured to be electrically coupled to a current source.