Braided stent to be implanted in a blood vessel

Abstract

A braided stent to be implanted in a blood vessel comprises a hollow body which is stretchable in its longitudinal direction and whose circumferential surface is formed by a braid of a multiplicity of filamentary elements which, in the expanded state of the braided stent, intersect a plane, perpendicular to the longitudinal direction, at a braiding angle. The braided stent has a smaller braiding angle in a central portion than in its distal and proximal portions which adjoin the central portion in the longitudinal direction.

1 . A braided stent to be implanted in a blood vessel, in particular in the carotid artery, with a hollow body which is stretchable in its longitudinal direction and whose circumferential surface having a braid of a multiplicity of filamentary elements which, in the expanded state of the braided stent, intersect a plane, perpendicular to the longitudinal direction, at a braiding angle, wherein the braided stent has a smaller braiding angle in a central portion than in its distal and proximal portions which adjoin the central portion in the longitudinal direction.  
   
   
       2 . The braided stent as claimed in  claim 1 , wherein the central portion in the expanded state has a smaller external diameter than the distal and the proximal portions.  
   
   
       3 . The braided stent as claimed in  claim 1 , wherein, in its expanded state, it has an external diameter which changes continuously, preferably decreases, from its proximal end to its distal end.  
   
   
       4 . The braided stent as claimed in  claim 3 , wherein the external diameter in the central portion is reduced still further compared to a continuous change.  
   
   
       5 . The braided stent as claimed in  claim 1 , wherein, at the distal and proximal portions, it has an external diameter which is greater than the internal diameter of the blood vessel at the site where the respective portion lies after the implantation.  
   
   
       6 . The braided stent as claimed in  claim 2 , wherein, at the distal and proximal portions, it has an external diameter which is greater than the internal diameter of the blood vessel at the site where the respective portion lies after the implantation.  
   
   
       7 . The braided stent as claimed in  claim 1 , wherein, in the central portion, it has an external diameter which is equal to or slightly smaller than the dilated internal diameter of the blood vessel at the site where the central portion lies after the implantation.  
   
   
       8 . The braided stent as claimed in  claim 2 , wherein, in the central portion, it has an external diameter which is equal to or slightly smaller than the dilated internal diameter of the blood vessel at the site where the central portion lies after the implantation.  
   
   
       9 . The braided stent as claimed in  claim 1 , wherein the braid has a plain weave.  
   
   
       10 . The braided stent as claimed in  claim 1 , wherein the filamentary elements are made from a material with a shape-memory effect, in particular from nitinol.  
   
   
       11 . The braided stent as claimed in  claim 1 , wherein it is coated with a medi-cally active substance.  
   
   
       12 . The braided stent as claimed in  claim 1 , wherein it has a conically widening crown at its two ends.  
   
   
       13 . Method for treating an aneurysm comprising the step of implanting the braided stent as claimed in  claim 1  into a vessel comprising an aneurysm at the position of the aneurysm.