Stent for treating vulnerable plaque

Abstract

An intravascular stent assembly for implantation in a body lumen, such as a coronary artery, is designed to treat a lesion with vulnerable plaque by reducing the fibrous cap stresses. The stent includes distal, proximal, and center sections where the center section is configured to treat the vulnerable plaque. The stent consists of radially expandable cylindrical rings generally aligned on a common longitudinal stent axis and either directly connected or interconnected by one or more interconnecting links placed so that the stent is flexible in the longitudinal direction while providing high degrees of radial strength and vessel scaffolding.

1 . An intravascular stent, comprising: a plurality of a first set of cylindrical rings and a plurality of a second set of cylindrical rings, each set of cylindrical rings being radially expandable, longitudinally aligned, and each with a first delivery diameter and a second implanted diameter; a plurality of links connecting a plurality of adjacent cylindrical rings; wherein the stent includes a distal section, a center section, and a proximal section; wherein the first set of rings are formed with a first cross-sectional width and the second set of rings are formed with a second, relatively smaller cross-sectional width.  
   
   
       2 . The stent of  claim 1 , wherein the first set of rings are located within the proximal section and the distal section of the stent and the second set of rings are located within the center section of the stent.  
   
   
       3 . The stent of  claim 1 , wherein the links comprise a first set with a first cross-sectional width and a second set with a second, relatively smaller cross-sectional width than the width of the first set of links.  
   
   
       4 . (canceled)  
   
   
       5 . The stent of  claim 1 , wherein a plurality of the links are formed with W-shaped undulations.  
   
   
       6 . The stent of  claim 1 , wherein the first set of rings are formed with V-shaped and U-shaped undulations and wherein the second set of rings are formed with V-shaped undulations.  
   
   
       7 . The stent of  claim 1 , wherein the second set of rings is formed with U-shaped undulations.  
   
   
       8 . The stent of  claim 1 , wherein the first set of rings and the second set of rings are formed with substantially U-shaped undulations.  
   
   
       9 . The stent of  claim 1 , wherein adjacent rings are connected with three links.  
   
   
       10 . The stent of  claim 1 , wherein the first set of rings and the second set of rings are located with the proximal section and the distal section of the stent and the links are located within the center section of the stent.  
   
   
       11 . The stent of  claim 10 , wherein there are six links connecting two rings.  
   
   
       12 . The stent of  claim 10 , wherein twelve links connect two rings.  
   
   
       13 . The stent of  claim 10 , wherein a plurality of the first set of rings and a plurality of the second sets of rings are directly connected.  
   
   
       14 - 22 . (canceled)  
   
   
       23 . The stent of  claim 1 , wherein the stent is self-expanding.  
   
   
       24 . The stent of  claim 23 , wherein the material forming the cylindrical rings embodies shape memory characteristics.  
   
   
       25 . The stent of  claim 24 , wherein the shape memory material is a superelastic material.  
   
   
       26 . The stent of  claim 25 , wherein the superelastic material is nickel-titanium.  
   
   
       27 - 46 . (canceled)  
   
   
       47 . An intravascular stent, comprising: a first set of cylindrical rings and a plurality of a second set of cylindrical rings, each set of cylindrical rings being radially expandable, longitudinally aligned, and each with a first delivery diameter and a second implanted diameter; a plurality of links connecting a plurality of adjacent cylindrical rings; wherein the stent includes a distal section, a center section, and a proximal section; wherein the first set of rings are formed with first undulations having a first cross-sectional width and the second set of rings are formed with non-overlapping undulations having a second, relatively smaller cross-sectional width, and the second set of rings having a higher concentration of undulations than the first section.  
   
   
       48 . The stent of  claim 47 , wherein the first set of rings are located within the proximal section of the stent and the second set of rings are located within the center section of the stent.  
   
   
       49 . The stent of  claim 48 , further comprising a third set of cylindrical rings are located within the distal section of the stent, wherein the third set of cylindrical rings are formed with undulations having the first cross-sectional width.  
   
   
       50 . The stent of  claim 47 , wherein the links comprise a first set with a first cross-sectional width and a second set with a second, relatively smaller cross-sectional width than the width of the first set of links, and the first set of links connect the first set of rings together and a plurality of the second set of links connect a plurality of the second set of rings together.  
   
   
       51 . The stent of  claim 47 , wherein the first set of links are formed with W-shaped undulations, and the second set of links are straight.  
   
   
       52 . The stent of  claim 47 , wherein the first set of rings are formed with V-shaped and U-shaped undulations and wherein the second set of rings are formed with V-shaped and U-shaped undulations.  
   
   
       53 . A method for delivering an intravascular stent in an artery having vulnerable plaque, comprising: 
 providing an intravascular stent delivery assembly comprising an elongated catheter for delivering the intravascular stent having a distal section, a proximal section, and a center section, each section having links and rings with undulations, wherein the undulations of the center section are non-overlapping and wherein the center section has a higher undulation concentration than the distal section and proximal section so that less stress is effected on the tissue of the artery by the center section than by the distal and proximal sections;    advancing the stent delivery assembly into an atherosclerotic artery within the patient's body lumen;    positioning the stent in a region of the artery containing vulnerable plaque;    implanting the stent in the artery such that only the center section of the stent apposes and contacts a region of the artery containing vulnerable plaque;    withdrawing the stent delivery catheter assembly from the patient.