Stents for angioplasty

Abstract

This invention is 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. The stent has a plurality of bridge elements having 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 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 having 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 being connected between a first peak and a first valley of the second segment in a manner such that the U-shaped portion extends in the direction of the first peak of the first segment and the first valley of the second 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 plurality of bridge elements, wherein the U-shaped portion of the plurality of bridge elements is oriented in one direction between the first and second annular segments and in the opposite direction between the second and third annular segments. 
   
   
       4 . The stent of  claim 1  wherein the connector arm of the bridge element joins the annular segment at a zero point of the sinusoidal shape. 
   
   
       5 . The stent of  claim 4  wherein each connector arm joins each annular segment at a zero point of the sinusoidal shape. 
   
   
       6 . The stent of  claim 1  further comprising a third annular segment connected by bridge elements to the second annual segment, wherein the bridge elements join zero points separated by 360° between the first and second adjacent segments, and further wherein the bridge elements join zero points separated by 720° between the second and third adjacent segments. 
   
   
       7 . A method of preventing restenosis in a vessel comprising:
 providing a stent having a substantially tubular body defining a longitudinal axis, the stent 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 having 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 being connected between a first peak and a first valley of the second segment in a manner such that the U-shaped portion extends in the direction of the first peak of the first segment and the first valley of the second 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 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 longitudinally with the valleys of the second segment, the plurality of bridge elements having 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 being connected between a first peak and a first valley of the second segment in a manner such that the U-shaped portion extends in the direction of the first peak of the first segment and the first valley of the second segment.   
   
   
       9 . The method of  claim 8  wherein the forming step is by a method selected from one 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, the first bridge element having a first end connected to the first annular segment at a zero point of the sinusoidal wave shape and having a second end connected to the second annular segment at a zero point of the sinusoidal wave shape, the second bridge element having a first end connected to the first annular segment at a zero point of the sinusoidal wave shape spaced 360° from the connection of the first bridge element to the first annular segment and a second end connected to the second annular segment at a zero point of the sinusoidal wave shape spaced 360° from the connection of the first bridge element to the second segment, the first and second bridge elements and the portion of the first and second annular segments between the connection points of the bridge elements 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;   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 and a second end connected to an annular segment adjacent to the one annular segment at a zero point of the sinusoidal wave shape of the adjacent annular segment, the annular segments and bridge elements being configured such that when compression, flexure and torsion forces are applied to the stent they generate first maximum stress regions, second maximum stress regions, and third maximum stress regions, where the first, second, and third maximum stress regions do not overlap.   
   
   
       12 . The stent of  claim 11  wherein each bridge element includes a U-shaped portion between first and second connector arms and wherein the first maximum stress regions are located about the peaks and valleys of the annular segments, the second maximum stress regions are located about the apex of the U-shaped portion of the bridge element and the third maximum stress regions are located about the points of connection of the bridge elements and annular segments.