An expandable, elongate flexible conduit is provided for placement in a tubular body structure. An exemplary conduit includes a plurality of flexible longitudinal members defining in an unexpanded state a lumen, the members being radially expandable at preselected intervals to define a longitudinally oriented array of open-sided cages separated by less-expanded tubular segments, at least one of the open-sided cages having a diameter varying along its length and each of the open-sided cages having a maximum diameter larger than a diameter of the less-expanded tubular segments.