Stent with anti-migration features

Abstract

An implantable medical device for implantation within a passageway of a patient comprises a stent including a plurality of wires, at least one of the plurality of wires having a cross-section having a first tapered point, and a covering layer having an inner diameter and an outer diameter. In some embodiments, the plurality of wires may be disposed at least partially around the covering layer. Additionally in some embodiments, the first tapered point may extend outward further than the outer diameter of the covering layer.

What is claimed is: 
     
         1 . An implantable medical device for implantation within a passageway of a patient, the device comprising:
 a tubular framework including a plurality of interwoven wires, at least one of the plurality of interwoven wires comprising a cross-section having a first tapered point and a second tapered point opposite the first tapered point, the cross-section of the at least one wire taken transverse to a longitudinal length of the wire such that the first and second tapered points extend along the longitudinal length of the wire;   a covering layer having a central longitudinal axis and an inner diameter and an outer diameter;   wherein the covering layer covers at least a portion of the framework and extends between adjacent wires of the plurality of interwoven wires included in the portion of the framework.   
     
     
         2 . The implantable medical device of  claim 1 , wherein the first and second tapered points extend perpendicular to the central longitudinal axis. 
     
     
         3 . The implantable medical device of  claim 1 , wherein the first and second tapered points extend at an angle to the central longitudinal axis. 
     
     
         4 . The implantable medical device of  claim 1 , wherein an entirety of the covering layer is disposed completely over the plurality of interwoven wires such that an inner surface of the covering layer contacts the first tapered point and an outer surface of the covering layer defines a bump over the first tapered point. 
     
     
         5 . The implantable medical device of  claim 1 , wherein the first tapered point extends outward further than the outer diameter of portions of the covering layer that extend between the adjacent wires. 
     
     
         6 . The implantable medical device of  claim 5 , wherein the second tapered point is embedded within the covering layer. 
     
     
         7 . The implantable medical device of  claim 5 , wherein the second tapered point extends inward further than the inner diameter of the portions of the covering layer that extend between the adjacent wires. 
     
     
         8 . The implantable medical device of  claim 1 , wherein the cross-section of the at least one of the plurality of interwoven wires further comprises third and fourth tapered points. 
     
     
         9 . The implantable medical device of  claim 8 , wherein the cross-section of the at least one of the plurality of interwoven wires is a diamond. 
     
     
         10 . The implantable medical device of  claim 8 , wherein the cross-section of the at least one of the plurality of interwoven wires is a square. 
     
     
         11 . The implantable medical device of  claim 8 , wherein the cross-section of the at least one of the plurality of interwoven wires is a trapezoid. 
     
     
         12 . The implantable medical device of  claim 8 , wherein the third and fourth tapered points are embedded within the covering layer. 
     
     
         13 . The implantable medical device of  claim 1 , wherein the cross-section of the at least one of the plurality of interwoven wires further comprises at least one rectangular projection disposed between the first and second tapered points. 
     
     
         14 . The implantable medical device of  claim 13 , wherein the at least one rectangular projection includes first and second opposing rectangular projections. 
     
     
         15 . The implantable medical device of  claim 14 , wherein the first and second opposing rectangular projections are embedded within the covering layer. 
     
     
         16 . An implantable medical device for implantation within a passageway of a patient, the device comprising:
 a tubular framework including a plurality of interwoven wires, at least one of the plurality of interwoven wires comprising a cross-section having a first tapered point oriented radially outward from a central longitudinal axis of the framework and a second tapered point oriented radially inward toward the central longitudinal axis of the framework, the cross-section of the at least one wire taken transverse to a longitudinal length of the wire such that the first and second tapered points extend along the longitudinal length of the wire; and   a covering layer disposed over a portion of the framework and extending between adjacent wires of the plurality of interwoven wires included in the portion of the framework;   wherein the first tapered point extends radially outward further than an outer diameter of the covering layer; and   wherein the second tapered point extends radially inward further than an inner diameter of the covering layer.   
     
     
         17 . The implantable medical device of  claim 16 , wherein the cross-section of the at least one of the plurality of interwoven wires further comprises third and fourth tapered points. 
     
     
         18 . The implantable medical device of  claim 17 , wherein the third and fourth tapered points are embedded within the covering layer. 
     
     
         19 . An implantable medical device for implantation within a passageway of a patient, the device comprising:
 a tubular framework including a plurality of interwoven wires, at least one of the plurality of interwoven wires comprising a cross-section having a first tapered point oriented radially outward from a central longitudinal axis of the framework and a second tapered point oriented radially inward toward the central longitudinal axis of the framework, the cross-section of the at least one wire taken transverse to a longitudinal length of the wire such that the first and second tapered points extend along the longitudinal length of the wire; and   a covering layer disposed over the framework and extending between adjacent wires of the plurality of interwoven wires, the covering layer having an inner diameter and an outer diameter;   wherein the first tapered point is embedded in the covering layer and the second tapered point extends radially inward further than the inner diameter of the covering layer.   
     
     
         20 . The implantable medical device of  claim 19 , wherein the cross-section of the at least one of the plurality of interwoven wires further comprises first and second opposing rectangular projections disposed between the first and second tapered points.