Devices including a self-expandable member having a proximal end portion and a main body portion. The self-expandable member is movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within a vessel or duct of a patient. The expandable member includes a plurality of cell structures with the cell structures in the main body portion extending circumferentially around a longitudinal axis of the expandable member and the cell structures in the proximal end portion extending less than circumferentially around the longitudinal axis of the expandable member to form first and second peripheral rails that vary in width along their lengths.