Dialysis Catheters with Fluoropolymer Additives

Abstract

A venous access catheter shaft and method of using and manufacturing such a catheter is provided. In one aspect of the invention, a catheter is provided comprising a base polymer having a Shore A durometer of 85A or lower, with 2.0% percent by weight of surface modifier, and a radiopaque filler comprising between 20-40 percentage by weight. In another aspect of the invention, a method reducing thrombus accumulation on a venous access catheter is provided wherein the catheter surface's resistance to thrombus formation is enhanced during indwell time by lowering the durometer rating of the base polymer of the catheter without increasing the amount of surface modifier additive. In another aspect of the invention, a method of manufacturing a catheter shaft is provided, wherein the shaft is formed comprising a base polymer having a Shore A durometer of 85A or lower, with 2.0% percent by weight of surface modifier, and a radiopaque filler comprising 30% by weight barium sulfate, and optionally a colorant of 0.2% weight.

What is claimed is: 
     
         1 . A catheter comprising:
 a catheter shaft (a) defining first and second shaft lumens and (b) forming a distal portion of the catheter, wherein the distal portion of the catheter includes a distal end portion having a distal tip and at least a portion of the distal end portion is substantially sloped with a sloped face that is angled proximally away from the distal tip and is positioned at an acute angle relative to a longitudinal axis of the catheter shaft; and   wherein the catheter comprises a fluoropolymer comprising polyfluoro oligomeric groups; wherein the fluoropolymer is characterized by a weight average molecular weight (Mw) greater than 13 kDa.   
     
     
         2 . The catheter of  claim 1 , wherein the polydispersity index of said fluoropolymer is less than or equal to 2.0. 
     
     
         3 . The catheter of  claim 1 , wherein said fluoropolymer is characterized by a weight average molecular weight (Mw) within the range of 14 kDa to 26 kDa. 
     
     
         4 . The catheter of  claim 1 , wherein said catheter comprises a polycarbonate-based polyurethane. 
     
     
         5 . The catheter of  claim 1 , wherein said catheter shaft further comprises about 17 weight percent to about 30 weight percent of a radiopaque material. 
     
     
         6 . The catheter of  claim 1 , wherein said catheter comprises about 1.4 weight percent to about 2.6 weight percent of said fluoropolymer. 
     
     
         7 . The catheter of  claim 5 , wherein said radiopaque material comprises barium sulfate. 
     
     
         8 . The catheter of  claim 7 , wherein said elongated tubular structure comprises up to about 30 weight percent of said barium sulfate. 
     
     
         9 . The catheter of  claim 1 , wherein said catheter shaft comprises a third lumen configured to selectively receive at least a portion of a guidewire, at least a portion of the third lumen sharing a common wall with at least a portion of the first lumen. 
     
     
         10 . The catheter of  claim 9 , wherein the shaft has an outer wall thickness within the range of 0.015-0.050 inches. 
     
     
         11 . The catheter of  claim 1 , wherein said catheter further comprises a plurality of extension tubes, and said extension tubes comprise said fluoropolymer. 
     
     
         12 . A catheter comprising:
 a shaft comprising a first lumen, a second lumen and a distal tip, each of said first and second lumens defined by a wall and terminating at an aperture; and   an apex in the wall defining the first lumen positioned distally of the second lumen aperture;   wherein the catheter comprises a fluoropolymer comprising polyfluoro oligomeric groups, said fluoropolymer characterized by a weight average molecular weight (Mw) greater than 13 kDa; and   wherein a height of said apex in relation to a longitudinal axis of said shaft is equal to or greater than a height of the wall defining the second lumen in relation to said longitudinal axis of said shaft.   
     
     
         13 . The catheter of  claim 12 , wherein the wall of said first lumen is characterized by an inner angle opposite said apex, said inner angle being between approximately 45 degrees and 135 degrees. 
     
     
         14 . The catheter of  claim 13 , wherein said inner angle is equal to or greater than about 90 degrees. 
     
     
         15 . The catheter of  claim 12 , further comprising a guidewire lumen. 
     
     
         16 . The catheter of  claim 12 , wherein at least one of said apex and said distal tip is configured to abut a wall of a blood vessel wall when inserted into said blood vessel. 
     
     
         17 . The catheter of  claim 12 , wherein the polydispersity index of said fluoropolymer is less than or equal to 2.0. 
     
     
         18 . The catheter of  claim 12 , wherein said fluoropolymer is characterized by a weight average molecular weight (Mw) within the range of 14 kDa to 26 kDa. 
     
     
         19 . The catheter of  claim 12 , wherein said catheter comprises a polycarbonate-based polyurethane. 
     
     
         20 . The catheter of  claim 12 , wherein said catheter shaft further comprises about 20 weight percent to about 30 weight percent of a radiopaque material. 
     
     
         21 . The catheter of  claim 12 , wherein said catheter comprises about 1.5 weight percent to about 2.5 weight percent of said fluoropolymer. 
     
     
         22 . The catheter of  claim 12 , wherein said catheter further comprises a plurality of extension tubes, and said extension tubes comprise said fluoropolymer.