Multiple layer vascular access device

Abstract

Single needle vascular access systems, devices methods for use in hemodialysis and apheresis procedures the device includes a multi-layer dilator. A single needle vascular access device includes a body having a venous and arterial passage with both in fluid communication with a vascular dilator. A cannulation needle is guided through the arterial passage and vascular dilator to cannulate a graft or fistula. Following cannulation, the dilator is gently introduced into the vessel. The cannulation needle is removed, and a venous tube is introduced through the venous passageway through the vascular dilator and into the fistula or graft. Blood is then removed from the body through the vascular dilator side orifices and returned through the venous line.

What is claimed is: 
     
         1 . A vascular access device comprising:
 a cannulation needle;   a first dilator coaxially mounted on the cannulation needle;   a second dilator, wherein the second dilator is configured to removably accept the first dilator with the cannulation needle such that the second dilator coaxially surrounds the first dilator, wherein the second dilator includes a proximal threaded male connector end and a distal end forming a second dilator tip, wherein the second dilator tip includes a plurality of second dilator side orifices, and wherein at least one of the plurality of second dilator side orifices, as viewed in cross section, has a funnel shape that is wider at its exterior surface than at its interior surface;   a vascular-access-device body, the vascular-access-device body further including a female threaded socket sized to receive the threaded male connector end of the second dilator; and   a first blood-conveying tube, wherein the second dilator is configured to accept insertion of the first blood-conveying tube after the first dilator with the cannulation needle has been removed from the second dilator.   
     
     
         2 . The device of  claim 1 , further comprising:
 a second blood-conveying tube in fluid communication with the second dilator; and   a blood-flow detector removably fastened to the cannulation needle to indicate that cannulation is complete,
 wherein the second dilator tip includes an end opening, 
 wherein a total area of all the second dilator side orifices is greater than a total area of the end opening, 
 wherein the end opening is tapered and rounded, 
 wherein the first blood-conveying tube includes a smaller-diameter distal portion and a larger-diameter proximal portion, 
 wherein the smaller-diameter distal portion is sized to fit within the second dilator to leave an annular space that is outside the smaller-diameter distal portion of the first blood-conveying tube and inside the second dilator and that is in fluid communication between the plurality of second dilator side orifices and the second blood-conveying tube, 
 wherein the annular space is in fluid communication with the second blood-conveying tube such that blood inside the second dilator travels only to the second blood-conveying tube, 
 wherein the plurality of second dilator side orifices are located in different radial directions along a circular cross-section circumference of the second dilator that is perpendicular to a longitudinal axis of the second dilator, 
 wherein the second dilator is rotatable during blood withdrawal without causing tissue damage, 
 wherein the device is configured to provide a post-treatment blood loss of less than five milliliters and a post-treatment bleeding time of less than five minutes, 
 wherein the second dilator tip has a longitudinal axis, wherein each one of the plurality of second dilator side orifices, as viewed from outside the second dilator tip, has an oval shape with a long axis and a short axis, and wherein the long axis of the oval shape is perpendicular to the longitudinal axis of the second dilator tip, and 
 wherein the vascular access device is configured to flow blood out through the first blood-conveying tube while receiving blood in through the plurality of second dilator side orifices. 
   
     
     
         3 . The device of  claim 1 , wherein the second dilator tip includes an end opening, and wherein the end opening is tapered and rounded. 
     
     
         4 . The device of  claim 1 , wherein the second dilator tip includes an end opening, and wherein the end opening is narrowed to substantially eliminate any annular space between the first dilator with the cannulation needle and the second dilator tip. 
     
     
         5 . The device of  claim 1 , further comprising a second blood-conveying tube in fluid communication with the second dilator, wherein the second dilator tip is narrowed relative to the proximal portion to seal to the outside of the first blood-conveying tube such that blood inside the second dilator travels only to the second blood-conveying tube. 
     
     
         6 . The device of  claim 1 , further comprising a second blood-conveying tube, wherein the second dilator is sized to form an annular space within the second dilator and outside the first blood conveying tube, wherein the annular space is in fluid communication with the second blood-conveying tube. 
     
     
         7 . The device of  claim 1 , further comprising a second blood-conveying tube, wherein the first blood-conveying tube includes a smaller-diameter distal portion and a larger-diameter proximal portion, wherein the smaller-diameter distal portion is sized to fit within the second dilator to leave an annular space that is outside the first blood-conveying tube and inside the second dilator and that is in fluid communication between the plurality of second dilator side orifices and the second blood-conveying tube. 
     
     
         8 . The device of  claim 1 , further comprising a blood-flow detector removably fastened to the cannulation needle to identify penetration. 
     
     
         9 . The device of  claim 1 , wherein the plurality of second dilator side orifices are located in different radial directions along a circular cross-section circumference of the second dilator that is perpendicular to a longitudinal axis of the second dilator. 
     
     
         10 . The device of  claim 1 , wherein the second dilator is rotatable during blood withdrawal without causing tissue damage. 
     
     
         11 . The device of  claim 1 , wherein the device is configured to provide a post-treatment blood loss of less than five milliliters, and a post-treatment bleeding time of less than five minutes. 
     
     
         12 . The device of  claim 1 , wherein the second dilator tip has a beveled end. 
     
     
         13 . The device of  claim 1 , wherein the second dilator tip has a longitudinal axis, wherein each one of the plurality of second dilator side orifices, as viewed from outside the second dilator tip, has an oval shape with a long axis and a short axis, and wherein the long axis of the oval shape is perpendicular to the longitudinal axis of the second dilator tip. 
     
     
         14 . The device of  claim 1 , wherein the second dilator tip includes an end opening, and wherein a total area of all the second dilator side orifices is greater than a total area of the end opening. 
     
     
         15 . A vascular access device comprising:
 a cannulation needle;   a first dilator coaxially mounted on the cannulation needle;   a second dilator, wherein the second dilator is configured to removably accept the first dilator with the cannulation needle such that the second dilator coaxially surrounds the first dilator, wherein the second dilator includes a cylindrical proximal portion and a distal end forming a tapered second dilator tip, wherein the second dilator has a longitudinal axis, wherein the cylindrical proximal portion includes a plurality of second dilator side orifices, wherein at least one of the plurality of second dilator side orifices, as viewed in cross section, has a funnel shape that is wider at its exterior surface than at its interior surface;   a vascular-access-device body, wherein the second dilator has a female coupler configured to couple the second dilator to the vascular-access-device body; and   a first blood-conveying tube, wherein the second dilator is configured to accept insertion of the first blood-conveying tube after the first dilator with the cannulation needle has been removed from the second dilator.   
     
     
         16 . The device of  claim 15 , wherein each one of the plurality of second dilator side orifices, as viewed from outside the second dilator tip, has an oval shape with a long axis and a short axis, and wherein the long axis of the oval shape is perpendicular to the longitudinal axis of the second dilator tip. 
     
     
         17 . The device of  claim 15 , wherein the plurality of second dilator side orifices are located in different radial directions along a circular cross-section circumference of the second dilator that is perpendicular to a longitudinal axis of the second dilator. 
     
     
         18 . The device of  claim 15 , further comprising a second blood-conveying tube, wherein the second dilator is sized to form an annular space within the second dilator and outside the first blood conveying tube, wherein the annular space is in fluid communication with the second blood-conveying tube. 
     
     
         19 . The device of  claim 15 , further comprising an o-ring located to provide a seal between the second dilator and the vascular-access-device body when the second dilator is coupled to the vascular-access-device body. 
     
     
         20 . A device for accessing a dialysis site of a patient, the device comprising:
 a cannulation needle;   first means for dilating the dialysis site of the patient;   second means for dilating the dialysis site of the patient, wherein the second means for dilating includes means for removably receiving the first means for dilating, and wherein the second means for dilating includes means for removing fluid from the patient;   means for passing fluid in a first fluid path and a second fluid path, wherein the means for passing fluid is configured to receive the second means for dilating such that the second means for dilating is in fluid communication with the first fluid path; and   means for conveying fluid through the second fluid path and into the patient at the dialysis site.