Self-sealing PTFE vascular graft and manufacturing methods

Abstract

An implantable microporous ePTFE tubular vascular graft exhibits long term patency, superior radial tensile strength and suture hole elongation resistance. The graft includes a first ePTFE tube and a second ePTFE tube circumferentially disposed over the first tube. The first ePTFE tube exhibits a porosity sufficient to promote cell endothelization, tissue ingrowth and healing. The second ePTFE tube exhibits enhanced radial strength in excess of the radial tensile strength of the first tube.

1 . A multi-layered ePTFE graft comprising: 
 a first ePTFE tubular structure having a first internodal distance;    a second ePTFE tubular structure having a second internodal distance different than said first intemodal distance, said second ePTFE tubular structure being disposed about said first ePTFE tubular structure; and    a self-sealing gel interposed between said first and second ePTFE tubular structures, wherein said gel is selected from the group consisting of gelatin, collagen, albumin, casein, algin, carboxymethyl cellulose, carageenan, furcellan, agarose, guar, locus bean gum, gum arabic, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydroxyalkylmethyl cellulose, pectin, partially deacetylated chitosan, starch and starch derivatives, including amylase and amylopectin, xanthan, polylysine, hyaluronic acid, and its derivatives, heparin, their salts, and mixtures thereof.    
   
   
       2 . A multi-layered graft according to  claim 1 , wherein said first intemodal distance is greater than said second internodal distance.  
   
   
       3 . A multi-layered graft according to  claim 1 , wherein said second ePTFE tubular structure is disposed externally about said first ePTFE tubular structure.  
   
   
       4 . A multi-layered graft according to  claim 1 , wherein said self-sealing gel comprises a single layer having resealable properties.  
   
   
       5 . A multi-layered graft according to  claim 1 , wherein said self-sealing gel is flowable.  
   
   
       6 . A multi-layered ePTFE vascular graft useful for repeated hemoaccess comprising: 
 a first ePTFE tubular structure having a first internodal distance;    a second ePTFE tubular structure having a second internodal distance different than said first internodal distance, said second ePTFE tubular structure being disposed about said first ePTFE tubular structure; and    a self-sealing gel interposed between said first and second ePTFE tubular structures, wherein said gel is selected from the group consisting of gelatin, collagen, albumin, casein, algin, carboxymethyl cellulose, carageenan, furcellan, agarose, guar, locus bean gum, gum arabic, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydroxyalkylmethyl cellulose, pectin, partially deacetylated chitosan, starch and starch derivatives, including amylase and amylopectin, xanthan, polylysine, hyaluronic acid, and its derivatives, heparin, their salts, and mixtures thereof.    
   
   
       7 . A multi-layered graft according to  claim 6 , wherein said first internodal distance is greater than said second internodal distance.  
   
   
       8 . A multi-layered graft according to  claim 6 , wherein said second ePTFE tubular structure is disposed externally about said first ePTFE tubular structure.  
   
   
       9 . A multi-layered graft according to  claim 6 , wherein said self-sealing gel comprises a single layer having resealable properties.  
   
   
       10 . A multi-layered ePTFE graft comprising: 
 a first ePTFE tubular structure having a first internodal distance;    a second ePTFE tubular structure having a second internodal distance different than said first internodal distance, said second ePTFE tubular structure being disposed about said first ePTFE tubular structure; and    a biodegradable material interposed between said first and second ePTFE tubular structures.    
   
   
       11 . A multi-layered graft according to  claim 10 , wherein the biodegradable material is a gel.  
   
   
       12 . A multi-layered ePTFE graft comprising: 
 a first ePTFE tubular structure; and    a second ePTFE tubular structure, said second ePTFE tubular structure being disposed about said first ePTFE tubular structure;    wherein the graft exhibits a radial tensile strength of at least 0.48 kg/mm 2 .    
   
   
       13 . The multi-layered graft of  claim 12 , wherein said first ePTFE tubular structure has a first porosity and said second ePTFE tubular structure has a second porosity.  
   
   
       14 . The multi-layered graft of  claim 13 , wherein said second porosity is different than sand first porosity.  
   
   
       15 . A multi-layered ePTFE graft comprising: 
 a first ePTFE tubular structure; and    a second ePTFE tubular structure, said second ePTFE tubular structure being disposed about said first ePTFE tubular structure;    wherein the graft is capable of withstanding elongation of at least 690% without breaking.    
   
   
       16 . The multi-layered graft of  claim 15 , wherein said first ePTFE tubular structure has a first porosity and said second ePTFE structure has a second porosity.  
   
   
       17 . The multi-layered graft of  claim 16 , wherein said second porosity is different than said first porosity.  
   
   
       18 . A multi-layered ePTFE graft comprising: 
 a first ePTFE tubular structure; and    a second ePTFE tubular structure, said second ePTFE tubular structure being disposed about said first ePTFE tubular structure; and    a self-sealing material interposed between said first and second ePTFE tubular structures, wherein the graft exhibits no or immeasurable leakage 30 seconds subsequent to puncture with a water source.    
   
   
       19 . The multi-layered graft of  claim 18 , wherein said first ePTFE tubular structure has a first porosity and said second ePTFE tubular structure has a second porosity.  
   
   
       20 . The multi-layered graft of  claim 19 , wherein said second porosity is different than said first porosity.