Arteriovenous graft for hemodialysis with puncture-resistant posterior and side walls

Abstract

An arteriovenous dialysis access graft configured to be implanted in a subject includes: at least one flexible conduit having first and second end portions, wherein the first end portion is configured to connect to an artery of the subject and the second end portion is configured to connect to a vein of the subject such that blood flows through the at least one conduit from the first end portion to the second end portion; and at least one cannulation chamber positioned between the first end portion and the second end portion of the at least one conduit. The chamber includes: an elongated housing having an inlet at a first end thereof and an outlet at a second, opposed end thereof, a posterior wall, a pair of sidewalls, and an open anterior portion defining a cannulation port; a self-sealing material extending across the cannulation port; and a longitudinal passageway defined by the housing and the self-sealing material that extends from the inlet to the outlet of the housing. The housing of the at least one chamber is formed of a substantially rigid material such that, when a dialysis needle is inserted through the self-sealing material and the cannulation port, the needle is inhibited or prevented from extending through the posterior or the side walls of the housing.

That which is claimed is: 
     
         1 . An arteriovenous dialysis access graft configured to be implanted in a subject, com prising:
 at least one flexible conduit having first and second end portions, wherein the first end portion is configured to connect to an artery of the subject and the second end portion is configured to connect to a vein of the subject such that blood flows through the at least one conduit from the first end portion to the second end portion; and   at least one cannulation chamber positioned between the first end portion and the second end portion of the at least one conduit, the chamber com prising: 
 an elongated housing having an inlet at a first end thereof and an outlet at a second, opposed end thereof, a posterior wall, a pair of sidewalls, and an open anterior portion defining a cannulation port, wherein the cannulation port has a length that spans at least a major portion of a length of the housing; 
 a self-sealing material extending across the cannulation port; and 
   a longitudinal passageway defined by the housing and the self-sealing material that extends from the inlet to the outlet of the housing;   wherein the posterior wall and the sidewalls of the housing of the at least one chamber are configured such that, when a dialysis needle is inserted through the self-sealing material and the cannulation port, the needle is inhibited or prevented from extending through the posterior or the side walls of the housing.   
     
     
         2 . The arteriovenous dialysis access graft of  claim 1 , wherein:
 the at least one cannulation chamber com prises first and second cannulation cham bers;   the at least one conduit comprises a middle portion between the first and second end portions; and   the first cham ber is positioned between the first end portion and the middle portion of the at least one conduit;   the second chamber positioned between the middle portion and the second end portion of the at least one conduit.   
     
     
         3 . The arteriovenous dialysis access graft of  claim 2 , wherein the at least one conduit extends through the longitudinal passageway of each chamber. 
     
     
         4 . The arteriovenous dialysis access graft of  claim 2 , wherein:
 the at least one conduit comprises first, second and third flexible conduits, each conduit having a first and second end;   the first end of the first conduit is configured to connect to the artery of the subject and the second end of the first conduit is connected to the inlet of the first cham ber;   the first end of the second conduit is configured to connect to the vein of the subject and the second end of the second conduit is connected to the outlet of the of the second chamber; and   the first end of the third conduit is connected to the outlet of the first chamber and the second end of the third conduit is connected to the inlet of the second chamber.   
     
     
         5 . The arteriovenous dialysis graft of  claim 2 , wherein the first and second chambers, the middle portion of the conduit, and at least a portion of the first and second end portions of the conduit are covered by a veneer formed of a biocompatible material. 
     
     
         6 . The arteriovenous dialysis access graft of  claim 2 , wherein the at least one of the first and second chambers is curved such that the longitudinal passageway has an arc angle. 
     
     
         7 . The arteriovenous dialysis access graft of  claim 6 , wherein the arc angle is between about 5 and about 45 degrees to accommodate placement in an upper arm of the subject. 
     
     
         8 . The arteriovenous dialysis access graft of  claim 6 , wherein the arc angle is between about 5 degrees and about 60 degrees to accommodate placement in a forearm or lower extremity of the subject. 
     
     
         9 . The arteriovenous dialysis graft of  claim 2 , wherein the conduit and/or the chambers are formed of a biocompatible material. 
     
     
         10 . The arteriovenous dialysis graft of  claim 2 , wherein the self-sealing material comprises silicone. 
     
     
         11 . The arteriovenous dialysis graft of  claim 2 , wherein the at least one conduit comprises ePTFE. 
     
     
         12 . The arteriovenous dialysis graft of  claim 2 , wherein each chamber housing comprises at least one of a polymeric material and titanium. 
     
     
         13 . The arteriovenous dialysis graft of  claim 2 , wherein each chamber housing material provides tactile and/or audible feedback to an operator that the dialysis needle has contacted an interior portion of the posterior wall or one of the side walls. 
     
     
         14 . The arteriovenous dialysis graft of  claim 2 , wherein a bottom portion of each chamber is squared or flat to inhibit malpositioning and/or twisting of the graft. 
     
     
         15 . An arteriovenous dialysis access graft configured to be implanted in a subject, com prising:
 a flexible conduit defining a longitudinal flow passageway, the conduit having first and second end portions and a middle portion, wherein the first end portion is configured to connect to an artery of the subject and the second end portion is configured to connect to a vein of the subject such that blood flows through the longitudinal passageway of the conduit from the first end portion to the second end portion; and   first and second spaced-apart cannulation chambers with the conduit extending through each of the first and second cham bers, the first chamber positioned between the first end portion and the middle portion of the conduit, the second chamber positioned between the second end portion and the middle portion of the conduit, each chamber comprising: 
 an elongated chamber body surrounding the conduit, the chamber body comprising self-sealing material and a cannulation port that exposes the self-sealing material; and 
 an elongated shell embedded in the chamber body and extending generally parallel to the longitudinal flow passageway of the conduit, the shell including a posterior wall, a pair of sidewalls, and an open anterior portion facing the cannulation port of the chamber body; 
   wherein each shell is configured such that, when a dialysis needle is inserted through the cannulation port and the self-sealing material, the needle is inhibited or prevented from extending through the posterior or the side walls of the shell.   
     
     
         16 . The arteriovenous dialysis graft of claim of  claim 15 , wherein the chamber body includes an annular inner layer including the self-sealing material surrounding the conduit and an outer layer including the cannulation port around the inner layer, and wherein the shell is disposed between the inner and outer layers. 
     
     
         17 . The arteriovenous dialysis graft of  claim 15 , wherein the cannulation port includes a raised perimeter portion such that the cannulation port can be tactilely and/or visually identified. 
     
     
         18 . The arteriovenous dialysis graft of  claim 15 , wherein at least a major portion of a length of the middle portion of the conduit includes beading material. 
     
     
         19 . The arteriovenous dialysis graft of  claim 15 , wherein a portion of the conduit extending from the first chamber to the first end portion includes beading material and/or a portion of the conduit extending from the second chamber to the second end portion includes beading material. 
     
     
         20 . The arteriovenous dialysis graft of  claim 15 , wherein each chamber is curved to have an arc angle that is between about 10 and 30 degrees to accommodate placement in an arm of a subject. 
     
     
         21 . The arteriovenous dialysis graft of  claim 15 , wherein each chamber body has a flattened bottom to inhibit malpositioning and/or twisting of the graft.