Abstract: An expandable slide and lock stent comprises a tubular member that can be expanded from a collapsed state to an expanded state. The tubular member can comprise a reversing helical backbone and at least one rail member extending from the helical backbone in a circumferential direction. The backbone can have at least one engagement element that can be configured to receive a rail member to form the tubular member. In some embodiments, the reversing helical backbone can comprise a plurality of discrete segments having a variable profile and/or wave form. A plurality of regions of each backbone may have a recessed or “nesting” profile providing for a smaller overall stent profile in a compacted configuration, and improved stent retention as mounted on a balloon catheter.