Multi-lumen vascular grafts having improved self-sealing properties

Abstract

The present invention provides an implantable graft, including a primary tubular body having a first outer wall surface and a first inner wall surface defining a primary blood contacting lumen, and a secondary tubular body having a second outer wall surface and a second inner wall surface. The secondary tubular body is located about the primary tubular body to form a space therebetween. The primary and secondary tubular bodies are joined by at least one rib.

1 . An implantable graft, comprising: 
 a primary tubular body formed of ePTFE having a first inner wall surface and a first outer wall surface defining a primary blood contacting lumen;    a secondary tubular body formed of ePTFE having a second inner wall surface and a second outer wall surface, said secondary tubular body being located about said primary tubular body to form a space therebetween, wherein said primary and secondary tubular bodies are joined by at least one rib, said rib defining a plurality of secondary lumens; and    a self-sealing polymeric material located in at least one of said secondary lumens.    
   
   
       2 . A method of forming an implantable graft comprising a primary tubular body having a first inner wall surface and a first outer wall surface defining a primary blood contacting lumen; and a secondary tubular body having a second inner wall surface and a second outer wall surface, said secondary tubular body being located about said primary tubular body to form a space therebetween, wherein said primary and secondary tubular bodies are joined by at least one rib and define at least one secondary lumen, the method comprising the steps of: 
 pre-forming a PTFE structure from PTFE paste into a tubular shape including said primary lumen and said secondary lumen; and    extruding said pre-formed PTFE structure through a tubular mold having a die with spacing devices for holding open said secondary lumens to form a multi-lumen tube.    
   
   
       3 . The method according to  claim 2 , wherein said pre-forming step includes compressing said paste in said mold prior to said extruding step.  
   
   
       4 . The method according to  claim 3 , further comprising the step of expanding said multi-lumen tube along a longitudinal axis of said multi-lumen tube.  
   
   
       5 . The method according to  claim 4 , further comprising the step of sintering said multi-lumen tube so as to form said graft.  
   
   
       6 . The method according to  claim 2 , further comprising the step of adding a self-sealing polymeric material to at least one of said non-blood contacting lumen.  
   
   
       7 . The method according to  claim 6 , further comprising the step of treating at least a portion of said primary tubular body so as to create a drug delivery system to deliver a drug to an interior of said graft.  
   
   
       8 . The method according to  claim 7 , comprising the step of adding a therapeutic agent to at least said portion of said primary tubular body containing said drug delivery system.  
   
   
       9 . The method according to  claim 8 , wherein said therapeutic agent is selected from the group consisting of: an antibiotic agent, an anti-thrombogenic agent, an anti-inflammatory agent, an anesthetic agent, an anti-coagulant, a vascular cell growth promoter, a vascular cell growth inhibitor, and a cholesterol lowering agent.  
   
   
       10 . The method according to  claim 6 , further comprising the step of perforating a portion of said primary tubular body so as to create a plurality of first pores connecting an exterior of said graft with an interior of one or more of said secondary lumen, wherein said first pores are not present in said secondary lumen containing said self-sealing material.  
   
   
       11 . The method according to  claim 7 , further comprising the step of adding a therapeutic agent to one or more of said secondary lumen containing said first pores.  
   
   
       12 . The method according to  claim 11 , wherein said therapeutic agent is selected from the group consisting of: an antibiotic agent, an anti-thrombogenic agent, an anti-inflammatory agent, an anesthetic agent, an anti-coagulant, a vascular cell growth promoter, a vascular cell growth inhibitor, and a cholesterol lowering agent.  
   
   
       13 . The method according to  claim 6 , further comprising the step of treating at least a portion of said secondary tubular body so as to create a drug delivery system to deliver a drug to an exterior of said graft.  
   
   
       14 . The method according to  claim 7 , comprising the step of adding a therapeutic agent to at least said portion of said secondary tubular body containing said drug delivery system.  
   
   
       15 . The method according to  claim 14 , wherein said therapeutic agent is selected from the group consisting of: an antibiotic agent, an anti-thrombogenic agent, an anti-inflammatory agent, an anesthetic agent, an anti-coagulant, a vascular cell growth promoter, a vascular cell growth inhibitor, and a cholesterol lowering agent.  
   
   
       16 . The method according to  claim 2 , further comprising the step of perforating a portion of said secondary tubular body so as to create a plurality of second pores connecting said primary lumen of said graft with one or more of said secondary lumen, wherein said second pores are not present in said secondary lumen containing said self-sealing material.  
   
   
       17 . The method according to  claim 16 , further comprising the step of adding a therapeutic agent to one or more of said secondary lumen containing said second pores.  
   
   
       18 . The method according to  claim 17 , wherein said therapeutic agent is selected from the group consisting of: an antibiotic agent, an anti-thrombogenic agent, an anti-inflammatory agent, an anesthetic agent, an anti-coagulant, a vascular cell growth promoter, a vascular cell growth inhibitor, and a cholesterol lowering agent.  
   
   
       19 . The method according to  claim 2 , further comprising the step of forming a textile cover for said graft.  
   
   
       20 . The method according to  claim 19 , further comprising the step of adhering said textile cover onto said graft after or simultaneous with said step of forming said textile cover for said graft.  
   
   
       21 . An implantable graft, comprising: 
 a first tubular blood contacting member having a first inner wall surface and a first outer wall surface and defining a blood contacting lumen;    a second tubular non-blood contacting member having a second inner wall surface and a second outer wall surface, said non-blood contacting member being arranged at least partially non-concentrically about said blood contacting member so as to define at least one non-blood contacting lumen therebetween, wherein at least a portion of said first outer wall and said second inner wall are in contact and contiguous along a length of said graft, said members being laminated along said portion.    
   
   
       22 . A method of forming a graft according to  claim 21 , comprising the steps of: 
 extruding a first tubular member from PTFE paste having a first inner wall surface and a first outer wall surface defining a primary blood contacting lumen;    extruding a second tubular member from PTFE paste having a second inner wall surface and a second outer wall surface;    arranging said second tubular member non-concentrically about said first tubular member along a length of said graft such that a portion of said first outer wall contacts a portion of said second inner wall; and    laminating said portions together.    
   
   
       23 . The method according to  claim 22 , wherein said laminating step includes at least one of heat setting, adhesive welding, and applying a uniform force to said graft.  
   
   
       24 . An implantable graft, comprising: 
 a first tubular body having an inner wall and outer wall, said inner wall defining a first blood contacting lumen; and    at least two non-blood contacting lumens positioned between said inner and outer walls of said tubular body and longitudinally aligned with said blood-contacting lumen.    
   
   
       25 . An implantable graft, comprising: 
 a primary tubular body having a first outer wall surface and a first inner wall surface defining a primary blood-contacting lumen; and    a secondary tubular body having an outer wall surface and an inner wall surface, said secondary tubular body being located about said primary tubular body, wherein said primary and secondary tubular bodies are joined by at least one rib; wherein at least a portion of the outer wall of the primary tubular body, at least a portion of the inner wall of the secondary tubular body, and the at least one rib define at least one secondary lumen; and wherein the at least one secondary lumen is capable of containing (i) a polymeric material that self-compresses upon puncture and (ii) a physiologically or pharmaceutically active agent.    
   
   
       26 . An implantable graft, comprising: 
 a primary tubular body having an outer wall surface and an inner wall surface defining a primary blood-contacting lumen; and    a secondary tubular body having an outer wall surface and an inner wall surface, said secondary tubular body being located about said primary tubular body, wherein said primary and secondary tubular bodies are joined by at least one rib; wherein at least a portion of the outer wall of the primary tubular body, at least a portion of the inner wall of the secondary tubular body, and the at least one rib define at least one secondary lumen; and wherein the at least one secondary lumen comprises at least one polymer or copolymer selected from the group consisting of silicone rubbers, synthetic rubbers, polyurethanes, polyethers, polyesters, and polyamides.    
   
   
       27 . An implantable graft, comprising: 
 a primary tubular body having an outer wall surface and an inner wall surface defining a primary blood-contacting lumen; and    a secondary tubular body having an outer wall surface and an inner wall surface, said secondary tubular body being located concentrically about said primary tubular body to form at least one secondary lumen therebetween, wherein the at least one secondary lumen contains at least one gel.    
   
   
       28 . The implantable graft of  claim 27 , wherein the gel is a hydrogel formed from a natural material.  
   
   
       29 . The implantable graft of  claim 28 , wherein the gel is selected from the group consisting of gelatin, collagen, albumin, casein, algin, carboxymethyl cellulose, carageenan, furcellaran, agarose, guar, locust bean gum, gum arabic, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydroxyalkylmethyl cellulose, pectin, partially deacetylated chitosan, starch and starch derivatives, and mixtures thereof.  
   
   
       30 . An implantable graft, comprising: 
 a primary tubular body having an outer wall surface and an inner wall surface defining a primary blood-contacting lumen; and a secondary tubular body having an outer wall surface and an inner wall surface, said secondary tubular body being located about said primary tubular body to form a space therebetween, wherein said primary and secondary tubular bodies are joined by at least one rib, wherein a self-sealing polymeric material and a drug are present in said space.