Patent ID: 7988721

Claim:
An offset rail stent being expandable from an axially-radially nested unexpanded state to an expanded state, the stent comprising a tubular member having a longitudinal axis, the tubular member comprising: a plurality of linkage strands extending in generally parallel directions along the longitudinal axis, each linkage strand having a plurality of frame elements being interconnected in an end-to-end fashion via at least one interconnection element, each frame element comprising at least one rail member having a free end separate from the free ends of rail members on other frame members, each rail member extending from the frame element in a circumferential direction, each frame element further comprising at least one engagement aperture, at least one rail member extending through an engagement aperture of an adjacent linkage strand, wherein each engagement aperture and each rail member are sized such that the at least one rail member can freely pass through a respective engagement aperture; and a plurality of coupling elements each attached to a free end of a respective rail member extending through the engagement aperture; a plurality of engagement mechanisms, each comprising at least one of the coupling elements engaged with at least one of the engagement apertures providing one-way movement of the coupling element engaged with a rail member in an expanding direction through the engagement aperture during expansion of the stent from an axially-radially nested unexpanded state to an expanded state and resisting movement of the coupling element engaged with the rail member in a contracting direction, opposite to the expanding direction, through the engagement aperture, thereby preventing contraction of the stent toward an axially-radially nested unexpanded state.