Partial encapsulation of stents

Abstract

An implantable medical device having a first and second ePTFE tube with a support layer positioned therebetween. The support layer may include a plurality of ring stents or may be a single stent structure. Slits may be cut into the first and/or second ePTFE tube to provide flexibility to the implantable medical device. These slits may be cut in any direction (longitudinally, circumferentially, diagonally, etc.) and may be oriented with respect to the support layer such that a desired degree of flexibility may be attained. The first and second ePTFE tubes may be bonded together through openings in the support layer to produce a partially encapsulated stent device.

What is claimed as new and desired to be protected by Letters Patent of the United States:  
     
         1 . An implantable medical device, comprising: 
 a first and second extruded ePTFE tube, wherein said first ePTFE tube comprises a plurality of slits formed therein; and    a radially expandable support layer comprising at least one stent, wherein said support layer is positioned between said first and second ePTFE tubes and is at least partially encapsulated therebetween.    
     
     
         2 . The implantable medical device according to  claim 1 , wherein said plurality of slits are oriented longitudinally on said first ePTFE tube.  
     
     
         3 . The implantable medical device according to  claim 2 , wherein each of said plurality of slits span a majority of the longitudinal length of said first ePTFE tube, leaving an unslitted region at both a proximal and distal end of said first ePTFE tube.  
     
     
         4 . The implantable medical device according to  claim 3 , wherein said region at both proximal and distal ends of said first ePTFE tube has a length in the range of approximately 5 mm to 10 mm.  
     
     
         5 . The implantable medical device according to  claim 3 , wherein each of said plurality of slits is approximately equivalent in length.  
     
     
         6 . The implantable medical device according to  claim 5 , wherein said plurality of slits comprise four slits spaced equidistantly around the circumference of said first ePTFE tube.  
     
     
         7 . The implantable medical device according to  claim 2 , wherein said plurality of slits are positioned in spaced apart intervals around the circumference of said first ePTFE tube.  
     
     
         8 . The implantable medical device according to  claim 7 , wherein two or more slits are positioned at each of selected circumferential positions on said first ePTFE tube.  
     
     
         9 . The implantable medical device according to  claim 2 , wherein said support layer comprises a plurality of ring stents formed in a zigzag pattern of alternating peaks and valleys.  
     
     
         10 . The implantable medical device according to  claim 9 , wherein said ring stents are positioned longitudinally such that the alternating peaks and valleys of neighboring ring stents are in phase with one another.  
     
     
         11 . The implantable medical device according to  claim 10 , wherein each of said plurality of slits is oriented to pass over either a ring stent peak or valley.  
     
     
         12 . The implantable medical device according to  claim 1 , wherein said plurality of slits are oriented circumferentially on said first ePTFE tube.  
     
     
         13 . The implantable medical device according to  claim 12 , wherein said plurality of slits are positioned in spaced apart intervals along the length of said first ePTFE tube.  
     
     
         14 . The implantable medical device according to  claim 13 , wherein two or more slits are positioned at each of selected longitudinal positions on said ePTFE tube.  
     
     
         15 . The implantable medical device according to  claim 14 , wherein two slits are positioned at each of said longitudinal positions, said slits having approximately the same arc length, each of the ends of said slits being spaced approximately equidistantly from one another.  
     
     
         16 . The implantable medical device according to  claim 15 , wherein the two slits at successive longitudinal positions are circumferentially offset from one another, such that taken together they span substantially the entire circumference of said first ePTFE tube.  
     
     
         17 . An implantable medical device, comprising: 
 a first and second extruded ePTFE tube, wherein said first ePTFE tube comprises a plurality of slits formed therein, wherein said plurality of slits are oriented longitudinally on said first ePTFE tube; and    a radially expandable support layer comprising at least one stent, wherein said support layer is positioned between said first and second ePTFE tubes and is at least partially encapsulated therebetween.    
     
     
         18 . An implantable medical device, comprising: 
 a first and second extruded ePTFE tube, wherein said first ePTFE tube comprises a plurality of slits formed therein, wherein said plurality of slits are oriented circumferentially on said first ePTFE tube; and    a radially expandable support layer comprising at least one stent, wherein said support layer is positioned between said first and second ePTFE tubes and is at least partially encapsulated therebetween.    
     
     
         19 . An implantable medical device, comprising: 
 a first and second extruded ePTFE tube, wherein said first ePTFE tube comprises a plurality of slits formed therein; and    a radially expandable support layer comprising a plurality of ring stents formed in a zigzag pattern of alternating peaks and valleys, wherein said support layer is positioned between said first and second ePTFE tubes and is at least partially encapsulated therebetween.    
     
     
         20 . A method for making an implantable medical device, comprising the steps of: 
 providing a first and second extruded ePTFE tube;    cutting a plurality of slits in said first ePTFE tube;    positioning a radially expandable support layer, comprising at least one stent, between said first and second ePTFE tubes; and    subjecting the device to heat and pressure such that said first and second ePTFE tubes bond together through openings in said support layer.    
     
     
         21 . The method according to  claim 20 , wherein the cutting step comprises cutting the plurality of slits in a longitudinal direction in said first ePTFE tube.  
     
     
         22 . The method according to  claim 21 , wherein said support layer comprises a plurality of ring stents formed in a zigzag pattern of alternating peaks and valleys, and wherein the positioning step comprises orienting the alternating peaks and valleys of neighboring ring stents in phase with one another.  
     
     
         23 . The method according to  claim 22 , wherein the positioning step further comprises positioning the slits to pass over either a ring stent peak or valley  
     
     
         24 . The method according to  claim 20 , wherein the cutting step comprises cutting the plurality of slits in a circumferential direction in said first ePTFE tube.