| 摘要 |
A stent (30) formed from cannula and having flexible segments (31) and high hoop strength segments (32) alternating therealong. Longitudinal struts or tie bars (41) interconnect the segments. Minimal length reduction of the strut occurs upon expansion. In the high hoop strength segment (32), struts (37) in a zig-zag configuration (Gianturco Z-stent) are initially parallel in the unexpanded strut condition. In the flexible segment (31), struts (58) extend from a respective C-shaped bend (59) to converge at the opposite ends thereof when unexpanded. In one embodiment, certain adjacent struts (39-41) of the hoop segment are spaced apart by elongated openings or gaps (46, 48) interposed therebetween and interconnected at their respective ends (42, 44) to form a T-shaped strut interconnection (45). The selected width (50, 51) of the first and third struts (54, 57) increases toward the ends (47, 48) of the elongated openings (46, 48) adjacent the strut interconnection (45). This strut width increase about one end of the strut significantly reduces the tensile strain exhibited about the opening end when the stent is radially expanded during manufacture. The tip length (52, 55) of the struts about the interconnection (45) is also adjusted (increased) along with the other C-shaped strut interconnections (59, 71) to further distribute the tensile strain developed during radial expansion.
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