Stents for angioplasty

Abstract

A stent has a substantially tubular body defining a longitudinal axis including first and second adjacent annular segments, each segment defining a substantially sinusoidal shape having a plurality of peaks and valleys, the peaks of the first segment extending toward the second segment and being aligned longitudinally with the valleys of the second segment. A plurality of bridge elements interconnect the annular segments. Each bridge element has a U-shaped portion between first and second connector arms, the first connector arm of one bridge element being connected between a first peak and a first valley of the first segment and the second connector arm of the one bridge element being connected between a first peak and a first valley of the second segment.

1 . A stent having a substantially tubular body defining a longitudinal axis comprising:
 first and second adjacent annular segments, each segment defining a substantially sinusoidal shape having a plurality of peaks and valleys, the peaks of the first segment extending toward the second segment and being aligned longitudinally with the valleys of the second segment;   a plurality of bridge elements each having a U-shaped portion between first and second connector arms, the first connector arm of one bridge element having a first end portion connected between a first peak and a first valley of the first segment and the second connector arm of the one bridge element having a second end portion connected between a first peak and a first valley of the second segment, the first end portion forming an angle of approximately 90° with the first annular segment, the second end portion forming an angle of approximately 90° with the second annular segment.   
     
     
         2 . The stent of  claim 1  wherein the U-shaped portions of the plurality of bridge elements are oriented in the same direction. 
     
     
         3 . The stent of  claim 1  further comprising a third annular segment connected to the second annular segment by a second plurality of bridge elements, the U-shaped portions of the bridge elements being oriented in one direction between the first and second annular segments and in a direction opposite the one direction between the second and third annular segments. 
     
     
         4 . The stent of  claim 1  wherein the first end portion of the first connector arm of the one bridge element is connected to the first annular segment at a zero point of the sinusoidal shape. 
     
     
         5 . The stent of  claim 4  wherein each end portion of each connector arm is connected to one of the annular segments at a zero point of the sinusoidal shape. 
     
     
         6 . The stent of  claim 1  further comprising a third annular segment connected by a second plurality of bridge elements to the second annual segment, the first end portions of the first connector arms and the second end portions of the second connector arms of the plurality of bridge elements being connected to the first and second annular segments at zero points of the sinusoidal shape separated by 360° of the sinusoidal shape, and the first end portions of the first connector arms and the second end portions of the second connector arms of the second plurality of bridge elements being connected to the second and third annular segments at zero points of the sinusoidal shape separated by 720° of the sinusoidal shape. 
     
     
         7 . A method of preventing restenosis in a vessel comprising:
 providing a stent having a substantially tubular body defining a longitudinal axis, the tubular body having a contracted condition and an expanded condition, the stent having first and second adjacent annular segments, each segment defining a substantially sinusoidal shape having a plurality of peaks and valleys, the peaks of the first segment extending toward the second segment and being aligned in a longitudinal direction with the valleys of the second segment, a plurality of bridge elements having a U-shaped portion between first and second connector arms, the first connector arm of one bridge element having a first end portion connected between a first peak and a first valley of the first segment and the second connector arm of the one bridge element having a second end portion connected between a first peak and a first valley of the second segment, the first end portion forming an angle of approximately 90° with the first annular segment, the second end portion forming an angle of approximately 90° with the second annular segment;   advancing the tubular body in the contracted condition through the lumen of the vessel to an area of stenosis; and   deploying the tubular body within the lumen of the vessel by expanding the tubular body from the contracted condition to the expanded condition.   
     
     
         8 . A method of making a stent comprising:
 providing a tubular blank defining a longitudinal axis; and   forming the blank into first and second adjacent annular segments connected by a plurality of bridge elements, each segment defining a substantially sinusoidal shape having a plurality of peaks and valleys, the peaks of the first segment extending toward the second segment and being aligned in a longitudinal direction with the valleys of the second segment, the plurality of bridge elements each having a U-shaped portion between first and second connector arms, the first connector arm of one bridge element having a first end portion connected between a first peak and a first valley of the first segment and the second connector arm of the one bridge element having a second end portion connected between a first peak and a first valley of the second segment, the first end portion forming an angle of approximately 90° with the first annular segment, the second end portion forming an angle of approximately 90° with the second annular segment.   
     
     
         9 . The method of  claim 8  wherein the forming step includes a method selected from the group consisting of laser incision, photo-incision, and electroerosion. 
     
     
         10 . A stent having a substantially tubular body defining a longitudinal axis comprising:
 first and second adjacent annular segments, each segment having a substantially sinusoidal wave shape;   first and second bridge elements each having a concave portion between first and second connector arms, the first bridge element having a first end connected to the first annular segment at a first zero point of the sinusoidal wave shape of the first annular segment and having a second end connected to the second annular segment at a first zero point of the sinusoidal wave shape of the second annular segment, the second bridge element having a first end connected to the first annular segment at a second zero point of the sinusoidal wave shape of the first annular segment spaced 360° on the sinusoidal wave shape from the first zero point and a second end connected to the second annular segment at a second zero point of the sinusoidal wave shape of the second annular segment spaced 360° on the sinusoidal wave shape from the first zero point, the first and second bridge elements and the portion of the first and second annular segments between the first and second zero points together defining a cell.   
     
     
         11 . A stent having a substantially tubular body defining a longitudinal axis comprising:
 a plurality of annular segments, each segment having a substantially sinusoidal wave shape including a plurality of peaks and valleys; and   a plurality of bridge elements, each bridge element having a first end connected to one annular segment at a zero point of the sinusoidal wave shape of the one annular segment and a second end connected to another annular segment adjacent to the one annular segment at a zero point of the sinusoidal wave shape of the another annular segment, the plurality of annular segments and plurality of bridge elements being configured such that the application of compression, flexure and torsion forces to the stent generates first maximum stress regions, second maximum stress regions, and third maximum stress regions, the first, second, and third maximum stress regions not overlapping.   
     
     
         12 . The stent of  claim 11  wherein each bridge element includes a concave portion between first and second connector arms, the concave portion having a pair of legs joined at an apex, the first maximum stress regions being located about the peaks and valleys of the plurality of annular segments, the second maximum stress regions being located about the apexes of the concave portions of the plurality of bridge elements and the third maximum stress regions being located about the points of connections of the plurality of bridge elements to the annular segments.