| 摘要 |
A radially expandable and contractible surgical stent 10 is provided formed from a shape memory material such as a Nickel-Titanium alloy. The stent 10 includes a series of wave-like struts 20 spaced apart by gaps 60. Each gap 60 is spanned by tie bars 70 at a maximum 64 width portion of the gap 60 or by an angled link 80 or a straight link 90 at a minimum 62 width portion of a gap 60. Hence, axial expansion or contraction of the stent 10 is avoided when the stent 10 is radially expanded or contracted. Each strut 20 is formed from a series of substantially linear legs 30 joined together by free bends 40 or attachment bends 50. The legs 30 and bends 40, 50 can be provided with an enhanced thickness 36 to augment resistance of the stent 10 to fracture when radially expanded or contracted. The stent 10 can be radially contracted to a diameter less than one-fourth of its radially expanded configuration when in a martensite phase. The stent 10 returns to a shape memory austenite phase when the stent 10 is unloaded or loaded below its yield strength and has a temperature above its transition temperature. The stent 10 can thus be easily collapsed and implanted within a body lumen for later radial expansion to support the body lumen.
|
