Dialysis valve and method

• US 7,540,859 B2
• Filed: 04/22/2004
• Issued: 06/02/2009
• Est. Priority Date: 04/23/2003
• Status: Active Grant

• Current Assignee: Interrad Medical, Inc.
• Original Assignee: Interrad Medical, Inc.
• Inventors: Rosenberg, Michael S., Claude, Timothy J., Hunter, David W., Barlow, Edward A.
• Primary Examiner(s): Sirmons; Kevin C
• Assistant Examiner(s): SCHMIDT, EMILY LOUISE
• Application Number:
  US10/497,137
• Publication Number:
  US 20050038396A1
• Time in Patent Office: 1,867 Days
• Field of Search: 604/4.01, 604/6.01, 604/6.16, 604/9, 604/96.01, 604/99.02, 604/100.03, 604/102.03, 604/103.08, 604/103.09, 60416701-16706, 604/207, 604246-247, 604249-250, 604/500, 604/507, 604/524, 604/526, 604/527, 604/890.1, 604/891.1, 606/158, 251/5, 251/4, 251/7, 251/8, 251/129.06
• US Class Current: 604/246
• CPC Class Codes: A61M 1/3655 Arterio-venous shunts or fistulae
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 39/22 Valves or arrangement of valves A61M39/02, A61M39/0247, A61M39/16 take precedence; regulating valves in infusion systems A61M5/16881; in devices worn by the patient for the reception of urine, faeces, catamenial or other discharge, or in colostomy devices A61F5/4405
• CPC Class Codes: A61M 39/228 with a tubular diaphragm constrictable by radial fluid force

Abstract

A dialysis valve includes a tube attached between an artery and a vein which, when elongated, simultaneously narrows in diameter at at least one location. The narrowed portion of the tube decreases the volume and velocity between the arterial and venous side of the patient to prevent damage or intimal hyperplasia on the venous side between dialysis treatments. When the valve is opened for dialysis, an unrestricted blood flow exists between the arterial and venous side, permitting a controlled, open blood flow during dialysis.

Claims

1. An implantable dialysis valve for fluid connection between an artery and a vein, comprising:

an implantable tube to convey blood from an arterial connection end to a venous connection end, the tube extending for a longitudinal length;

an actuation port to receive a fluid through a self-sealing membrane for adjustment of the longitudinal length of the tube; and

a hydraulically actuated bellows in fluid communication with the actuation port so as to adjust from a first length to a second length when the fluid is received through the membrane in the actuation port, the bellows being coupled with the tube so that when the bellows adjusts from the first length to the second length, the tube contemporaneously increases in longitudinal length and decreases in diameter at a narrowed portion, wherein the narrowest portion of the tube decreases in diameter while not fully closing.

2. The dialysis valve of claim 1 wherein the tube comprises a braided nitinol structure processed to exhibit superelasticity below normal human body temperature, the braided nitinol structure having an elastomeric coating, wherein the tube is repeatedly adjustable in longitudinal length and diameter.

3. The dialysis valve of claim 2 wherein the tube defines an inner surface that is substantially smooth and is coated with an anti-thrombogenic coating.

4. The dialysis valve of claim 3 wherein the bellows is double walled so as to define an inner wall space in fluid communication with the actuation port so that when fluid is urged into the inner wall space, the bellows increases in length and thereby actuates the tube to contemporaneously increase in longitudinal dimension and decreases in diameter at the narrowed portion.

5. The dialysis valve of claim 4 further comprising an implantable housing sized to fit between an artery and a vein when implanted, the housing containing the tube and the bellows, wherein the actuation port is attached to the housing such that the membrane is adjacent to skin when the housing is implanted.

6. The dialysis valve of claim 3, wherein the tube decreases in diameter at a narrowest portion while not fully closing to provide a blood flow rate through the tube of less than about 300 cc per minute when the tube is connected between an artery and a vein.

7. The dialysis valve of claim 1 wherein the tube is mounted to the bellows so that when the bellows is actuated to increase in length, the tube contemporaneously increases in longitudinal dimension and decreases in diameter at the narrowed portion.

8. An implantable dialysis valve for fluid connection between an artery and a vein, comprising:

an implantable housing sized to fit between an artery and a vein;

an arterial fistula graft connected with the housing to attach with the artery when the housing is implanted;

a venous fistula graft connected with the housing to attach with the vein when the housing is implanted;

an adjustable tube arranged in the implantable housing to convey blood from the arterial fistula graft to the venous fistula graft, the tube extending for a longitudinal length and defining an inner surface that is substantially smooth and is coated with an anti-thrombogenic coating, wherein the tube comprises a braided nitinol structure having an elastomeric coating;

an actuator to selectively adjust from a first length to a second length in response to fluid or electric control, the actuator being coupled with the tube so that when the actuator adjusts from the first length to the second length, the tube contemporaneously increases in longitudinal length and decreases in diameter at a narrowed portion.

9. The dialysis valve of claim 8 wherein the tube decreases in diameter at the narrowed portion while not fully closing the tube.

10. The dialysis valve of claim 9 wherein the tube decreases in diameter at the narrowed portion while not fully closing the tube to blood flow so that the tube operable to constrict and provide blood flow therethrough at an increased velocity to hinder the formation of thrombus or clotting.

11. The dialysis valve of claim 10 wherein the tube decreases in diameter at a narrowest portion while not fully closing to provide a blood flow rate through the tube of less than about 300 cc per minute when the tube is implanted between an artery and a vein.

12. The dialysis valve of claim 8 wherein the actuator comprises a fluid controlled bellows that adjusts from the first length to the second length, the bellows being in fluid communication with an actuation port that receives fluid through a self-sealing membrane for adjustment of the longitudinal length of the tube.

13. The dialysis valve of claim 12 wherein bellows is double walled so as to define an inner wall space in fluid communication with the actuation port so that when fluid is urged into the inner wall space, the bellows increases in length and thereby actuates the tube to contemporaneously increase in longitudinal length and decrease in diameter at the narrowed portion.

14. The dialysis valve of claim 12 wherein the actuation port is attached to the housing such that the membrane is adjacent to skin when the housing is implanted.

15. The dialysis valve of claim 8 wherein the actuator comprises an inflatable balloon adjustable to various degrees of inflation, the balloon acting upon the tube so that, when the balloon is inflated, the tube contemporaneously increases in longitudinal length and decreases in diameter at the narrowed portion.

16. The dialysis valve of claim 8 wherein the actuator comprises an adjustable nitinol spring attached to the tube such that, when the spring is controlled to shift from the first length to the second length, the tube contemporaneously increases in longitudinal length and decreases in diameter at the narrowed portion.

17. A method of controlling blood flow between and during dialysis treatments, comprising:

a. implanting a dialysis valve comprising a tube between a patient'"'"'s vein and an artery, the tube operable to convey fluids and defining a longitudinal dimension, a diameter and an inner surface, wherein the dialysis valve further comprises a bellows capable of being held at varying lengths, the bellows defining an interior chamber wherein the tube is mounted in the chamber so that when the bellows adjustably increases in length, the tube simultaneously increases in longitudinal dimension and at least a portion of the tube decreases in diameter;

b. narrowing the diameter of the tube in an adjustable manner between dialysis treatments at at least one location along the longitudinal dimension, wherein the diameter of the tube is narrowed while not fully closing the diameter to thereby provide blood flow through the tube between dialysis treatments; and

c. opening the diameter of the tube at the narrowed location by adjustably changing the longitudinal dimension of the tube to conduct a dialysis treatment, wherein the diameter of the tube is opened to thereby provide increased blood flow through the tube during the dialysis treatment.

18. The method of claim 17 wherein the tube comprises a braided nitinol structure processed to exhibit superelasticity below normal human body temperature coated with an elastomer allowing the tube to be repeatedly altered in longitudinal dimension and in diameter and still maintain fluid containing capability.

19. The method of claim 18 wherein the inner surface of the tube at the narrowed location is in a substantially circular configuration.

20. The method of claim 17 wherein the inner surface of the tube is substantially smooth and comprises an anti-thrombogenic coating.

21. The method of claim 17 wherein the bellows is double walled so as to define an inner wall space;

a hydraulic line is in fluid connection with the inner wall space so when a pressurized fluid is pumped into the inner wall space, the bellows increases in length, simultaneously increasing the longitudinal dimension of the tube.

22. The method of claim 17 wherein the diameter of the tube is narrowed to provide blood flow through the tube between dialysis treatments at a blood flow rate of less than about 300 cc per minute.