Squitieri hemodialysis and vascular access systems

Abstract

A hemodialysis and vascular access system comprises a subcutaneous composite PTFE silastic arteriovenous fistula having an indwelling silastic venous end which is inserted percutaneously into a vein and a PTFE arterial end which is anastomosed to an artery. Access to a blood stream within the system is gained by direct puncture of needle(s) into a needle receiving site having a tubular passage within a metal or plastic frame and a silicone upper surface through which needle(s) are inserted. In an alternate embodiment of the invention, percutaneous access to a blood stream may be gained by placing needles directly into the system (i.e. into the PTFE arterial end). The invention also proposes an additional embodiment having an arterialized indwelling venous catheter where blood flows from an artery through a tube and a port into an arterial reservoir and is returned to a vein via a port and a venous outlet tube distinct and distant from the area where the blood from the artery enters the arterial reservoir. The site where blood is returned to the vein is not directly fixed to the venous wall but is free floating within the vein. This system provides a hemodialysis and venous access graft which has superior longevity and performance, is easier to implant and is much more user friendly.

1. A Squitieri hemodialysis and vascular access system to shunt blood between a vein and an artery the system comprising:
 (a) a first tube having a first end adapted to be connected to the artery and a second end;  
 (b) a second tube having a first end adapted to be connected to the vein and including a plurality of apertures extending therethrough and having a second end; and  
 (c) a needle access port having a frame including a conduit extending therethrough, said frame having an inlet connected to the second end of the first tube and an outlet connected to the second end of the second tube to provide a flow path for blood and a silicone member protruding from the frame to provide access for needles into the flow path, wherein the needle access port includes: 
 an outer frame member having an upper surface including an aperture extending therethrough and downwardly extending walls about its periphery having inlet and outlet apertures, wherein the upper surface includes a lower portion having a plurality of teeth;  
 a silicone member mounted within the frame having a surface engaged by the frame teeth and an upwardly protruding portion extending through the frame aperture; and  
 a second frame member having a transverse conduit extending between the inlet and outlet apertures, an upper surface having a plurality of teeth engaging the silicone member to effect a seal and wherein the second frame member is positioned within the walls of the first frame member.  
 
 
     
     
       2. The Squitieri hemodialysis and vascular access system of  claim 1 , wherein:
 the first tube corresponds to PTFE tubing;  
 the second tube corresponds to silicone tubing; and  
 the protruding silicone member has an oval configuration.  
 
     
     
       3. The Squitieri hemodialysis and vascular access system of  claim 1 , wherein the first tube includes rings mounted thereabout to provide additional strength. 
     
     
       4. The Squitieri hemodialysis and vascular access system of  claim 1  further comprising:
 a second needle access port having an inlet and an outlet and silastic  silicone tubing coupling the inlet of the second needle access port to the outlet of the other needle access port and wherein the outlet of the second access port is coupled to the second end of the second tube.  
 
     
     
       5. The Squitieri hemodialysis and vascular access system of  claim 1  wherein:
 the first tube is provided as PTFE tubing which is adapted for attachment to the artery at one end and coupled to the access port at the other end; and  
 the second tube is provided as silicone tubing which is coupled to the needle access port at one end and is capable of being floated within the vein at the other end.  
 
     
     
       6. The Squitieri hemodialysis and vascular access system of  claim 1 , wherein:
 the first tube is inserted within an outer silicone tubing at the inlet to the needle access port.  
 
     
     
       7. The Squitieri hemodialysis and vascular access system of  claim 1 , further including:
 an adjustable band mounted about the first tube at the inlet to the needle access port to regulate blood flow.  
 
     
     
       8. The Squitieri hemodialysis and vascular access system of  claim 4 , wherein:
 a second needle access port is mounted to the needle access port, said ports having a single frame and a conduit extending longitudinally therethrough to the outlet tubing.  
 
     
     
       9. A Squitieri hemodialysis and vascular access system to shunt blood between a vein and an artery, the system including:
 (a) a first tube having a first end adapted to be connected to the artery;  
 (b) a second tube having a first end adapted to be connected to the vein and including a plurality of apertures extending therethrough and having a second end;  
 (c) a needle access port having a frame including a conduit extending therethrough, said frame having an inlet connected to the second end of the first tube and an outlet connected to the second end of the second tube to provide a flow path for blood and a silicone member protruding from the frame to provide access for needles into the flow path; and  
 a quick coupler for joining the first tube to the needle access port comprising a port member projecting outwardly from the frame inlet and having a circumferential slot extending thereabout, a cooperating member having an outer portion extending concentrically with the first tube and a portion extending outwardly therefrom and an outwardly sloped portion extending over the projecting port member and having an inner circumferential projection which engages the circumferential slot, and wherein the first tube extends over the port member to be engaged by the projecting portion of the cooperating member within the slot and a removable coupling which snaps over the cooperating member forcing it into a sealed engagement with the port member.  
 
     
     
       10. A Squitieri hemodialysis and vascular access system to shunt blood between a vein and an artery, the system including:
 (a) a first tube having a first end adapted to be connected to the artery;  
 (b) a second tube having a first end adapted to be connected to the vein and including a plurality of apertures extending therethrough and having a second end; and  
 (c) a needle access port having a frame including a conduit extending therethrough, said frame having an inlet connected to the second end of the first tube and an outlet connected to the second end of the second tube to provide a flow path for blood and a silicone member protruding from the frame to provide access for needles into the flow path, wherein the needle access port comprises: 
 a first member having a base, walls extending upwardly therefrom to form an enclosed area, and outwardly extending couplings on opposite walls thereof at the inlet and outlet of said port;  
 a second member having a top including an upper aperture, downwardly extending side walls engaging the walls of the first member and having a conduit extending from the inlet to the outlet and a silicone member projecting form the upper aperture to provide needle access; and  
 a tube mounted over each coupling and a coupler which fits over each tube to seal the tubes to the couplings.  
 
 
     
     
       11. The Squitieri hemodialysis and vascular access system of  claim 1 , wherein:
 the second tube is capable of being floated within a vein at the one end and the plurality of apertures in the second tube are distant from the site where the second tube is inserted into the vein, said second tube not being fixed to the vein wall.  
 
     
     
       12. A hemodialysis and vascular access system comprising:
 an arterialized indwelling venous catheter having a graft section provided from a material which is biocompatible with an artery, has a nonthrombogenic characteristic, which is adapted for long term attachment to an artery and which includes a region for repeated needle access and a catheter section, with a first end of said graft section adapted to be coupled to an artery and a portion of the catheter section adapted to be inserted within a vein at an insertion site, said catheter section portion having at least one opening in an end thereof with at least one of the at least one openings in the catheter section portion adapted to be within the vein itself and wherein the at least one opening is distant from the insertion site such that blood flows from the artery through the catheter and is returned to the vein through the at least one opening while providing laminar blood flow between the artery and the vein.    
     
     
       13. The hemodialysis and vascular access system of  claim 12 , further comprising:
 at least one needle having a first end coupled to a hemodialysis device and having a second end adapted for insertion directly into said graft section of the catheter to shunt the blood flow through the dialysis device.    
     
     
       14. The hemodialysis and vascular access system of  claim 13  wherein said graft section is provided from a first tube and said catheter section is provided from a second tube comprising multiple layers and a first end of said first tube is coupled to a first end of said second tube. 
     
     
       15. The hemodialysis and vascular access system of  claim 14  wherein said first and second tubes are adapted for percutaneously placement. 
     
     
       16. The hemodialysis and vascular access system of  claim 14  wherein the end of said second tube which is coupled to the first tube includes an enlarged portion in which the first end of said first tube is disposed. 
     
     
       17. A hemodialysis and vascular access system, comprising:
   an arterialized indwelling venous catheter having a graft section provided from a material which is biocompatible with an artery, has a nonthrombogenic characteristic, which is adapted for long term attachment to an artery and which includes a region of repeated needle access and a catheter section, with a first end of said first graft section adapted to be coupled to an artery and a portion of the catheter section adapted to be inserted within a vein at an insertion site, said catheter section portion having an outside diameter which is less than an inner diameter of the vein and having at least one opening in an end thereof with at least one of the at least one openings in the catheter section portion adapted to be within the vein itself and wherein the at least one opening is distant from the insertion site such that, in operation, blood flows from the artery through the catheter and is returned to the vein through the at least one opening while providing laminar blood flow between the artery and the vein and blood also flows through the vein uninterrupted around at least an outer portion of said catheter; and        at least one needle having a first end coupled to a hemodialysis device and having a second end adapted for insertion directly into the arterialized indwelling venous catheter to shunt the blood flow through the dialysis device.     
     
     
       18. The hemodialysis and vascular access system of  claim 17  wherein the graft section of said arterialized indwelling venous catheter is provided from a first tube and said catheter section is provided from a second tube comprising multiple layers and a first end of said first tube is coupled to a first end of said second tube. 
     
     
       19. The hemodialysis and vascular access system of  claim 18  wherein said first and second tubes are adapted for percutaneous placement. 
     
     
       20. The hemodialysis and vascular access system of  claim 18  wherein the end of said second tube which is coupled to the first tube includes an enlarged portion in which the first end of said first tube is disposed. 
     
     
       21. A hemodialysis and vascular access system as in  claim 17 , wherein the graft section comprises PTFE. 
     
     
       22. A hemodialysis and vascular access system as in  claim 17 , wherein the graft section comprises polyethylene terephthalate. 
     
     
       23. A hemodialysis and vascular access system as in  claim 17 , wherein the graft section has a diameter of approximately  7  mm. 
     
     
       24. A hemodialysis and vascular access system as in  claim 17 , wherein the first end of the graft section has a diameter of about  4  mm. 
     
     
       25. A hemodialysis and vascular access system as in  claim 17 , wherein the catheter section comprises silicone. 
     
     
       26. A hemodialysis and vascular access system as in  claim 17 , wherein a downstream end of the catheter section is provided with a bevel. 
     
     
       27. A hemodialysis and vascular access system as in  claim 17 , additionally comprising an access segment for receiving a needle to allow access to blood flowing through the catheter. 
     
     
       28. A hemodialysis and vascular access system as in  claim 27 , wherein the access segment comprises a self sealing material. 
     
     
       29. A hemodialysis and vascular access system as in  claim 28 , wherein the self sealing material comprises silicone. 
     
     
       30. A hemodialysis and vascular access system as in  claim 28 , wherein the access segment is removably connected to the access system. 
     
     
       31. A hemodialysis and vascular access system as in  claim 27 , further comprising a support structure in the access segment. 
     
     
       32. A hemodialysis and vascular access system as in  claim 31 , wherein the support structure comprises a frame. 
     
     
       33. A hemodialysis and vascular access system as in  claim 31 , wherein the support structure comprises ridges. 
     
     
       34. A hemodialysis and vascular access system as in  claim 33 , wherein the ridges comprise teeth. 
     
     
       35. A hemodialysis and vascular access system as in  claim 17 , wherein at least a portion of the indwelling venous catheter comprises multiple layers. 
     
     
       36. A hemodialysis and vascular access system as in  claim 35 , wherein the multiple layers comprise a first PTFE layer and a second silicone layer. 
     
     
       37. A hemodialysis and vascular access system as in  claim 36 , wherein the first PTFE layer is an inner PTFE layer and the second silicone layer is an outer silicone layer. 
     
     
       38. A hemodialysis and vascular access system as in  claim 37 , wherein the multiple layers further comprises a PTFE coating on the outer silicone layer. 
     
     
       39. A hemodialysis and vascular access system as in  claim 17 , wherein said graft section and said catheter section comprise a material selected from the group consisting of PTFE, silicone, or flexible plastic. 
     
     
       40. A hemodialysis and vascular access system as in  claim 17 , comprising first and second needle access sites. 
     
     
       41. A hemodialysis and vascular access system as in  claim 17 , wherein the catheter section comprises a long, flexible plastic tube. 
     
     
       42. A hemodialysis and vascular access system as in  claim 17 , wherein the region for repeated needle access comprises needle receiving sites( s )  and comprises an internal chamber that is tubular in shape.   
     
     
       43. A hemodialysis and vascular access system as in  claim 17 , wherein the region for repeated needle access comprises a self- sealing material.   
     
     
       44. A hemodialysis and vascular access system as in  claim 17 , wherein the catheter section comprises a silicone section. 
     
     
       45. A hemodialysis and vascular access system as in  claim 44 , wherein the silicone section is lined with PTFE. 
     
     
       46. A hemodialysis and vascular access system as in  claim 17 , wherein the region of repeated needle access comprises multiple layers. 
     
     
       47. A hemodialysis and vascular access system as in  claim 46 , wherein the multiple layers comprise PTFE on the inside and silicone on the outside. 
     
     
       48. A hemodialysis and vascular access system as in  claim 46 , wherein the multiple layers comprise PTFE on the inside and silicone disposed outside of the PTFE. 
     
     
       49. A hemodialysis and vascular access system as in  claim 17 , wherein the material providing the graft section comprises a thrombus resistant coating. 
     
     
       50. A hemodialysis and vascular access system as in  claim 49 , wherein the thrombus resistant coating comprises heparin. 
     
     
       51. A hemodialysis and vascular access system as in  claim 17 , wherein a nonthrombenic characteristic is provided by continuous flow of blood through at least the graft section.