Subcutaneous vascular access assemblies and related devices and methods

1. A vascular access assembly comprising:

a first tubular conduit;

a second tubular conduit;

an expandable stent graft that is coupled to the second tubular conduit adjacent a peripheral end of the second tubular conduit, wherein the expandable stent graft includes a first branch configured to couple to an artery, vein or arteriovenous graft of a patient such that the first branch permits blood flow through the artery, vein, or arteriovenous graft, wherein the expandable stent graft includes a second branch coupled to the second tubular conduit such that the artery, the vein, or the arteriovenous graft is in fluid communication with the second tubular conduit;

a restraint comprising a pull string coupled to filaments surrounding the expandable stent graft in a compressed state;

wherein the first tubular conduit is configured to couple to a central end of the second tubular conduit to form a flow path that extends from the artery, the vein, or the arteriovenous graft to a heart of the patient.

2. The vascular access assembly of claim 1 , wherein the expandable stent graft comprises a T-shape.

3. The vascular access assembly of claim 1 , wherein the second tubular conduit comprises a puncturable and self-sealing wall such that the wall may be punctured by insertion of a needle and then reseal upon withdrawal of the needle.

4. The vascular access assembly of claim 1 , further comprising a connector for coupling the first tubular conduit to the second tubular conduit.

5. The vascular access assembly of claim 1 , wherein the second tubular conduit is configured for delivery through a lumen of a deployment device.

6. The vascular access assembly of claim 1 , wherein the flow path extends from the brachial artery to a right atrium of the heart.

7. The vascular access assembly of claim 1 , wherein the vascular access assembly is configured to be implanted without establishing a venous anastomosis.

8. The vascular access assembly of claim 1 , further comprising a valve disposed adjacent a central end of the second tubular conduit, wherein the valve is configured to allow blood flow across the valve when the second tubular conduit is coupled to the first tubular conduit and to prevent blood flow across the valve when the second tubular conduit is uncoupled from the first tubular conduit.

9. The vascular access assembly of claim 1 , wherein the expandable stent graft is a self-expanding stent graft.

10. The vascular assembly of claim 1 , further comprising a tubular liner that is disposed within both the expandable stent graft and the second tubular conduit, wherein the tubular liner provides a continuous luminal surface for contact with blood of the patient.

11. The vascular assembly of claim 1 , further comprising a first therapeutic agent that is associated with one or both of an inner surface and an outer surface of the vascular access assembly, wherein the vascular access assembly is configured to deliver a therapeutically effective dose of the first therapeutic agent to the patient when the vascular access assembly is implanted within the patient.

12. A method for implanting a vascular access assembly into a patient, the method comprising:

inserting a central end of a first tubular conduit into a patient such that the central end of the first tubular conduit is positioned within a right atrium of a heart of the patient;

tunneling a peripheral end of the first tubular conduit through flesh of the patient to an incision adjacent a shoulder of the patient;

inserting a second tubular conduit into the patient such that the second tubular conduit extends from the incision adjacent the shoulder of the patient to an incision in the arm of the patient;

deploying a stent graft within an artery or an arteriovenous graft in the arm of the patient, wherein the stent graft is coupled to and disposed adjacent a peripheral end of the second tubular conduit;

pulling a pull string to remove a restraint from around the stent graft, wherein the stent graft transitions from a compressed state to an expanded state;

sealing an insertion site of the artery or the arteriovenous graft with a collar disposed around a periphery of the stent graft; and

coupling the first tubular conduit to the second tubular conduit.

13. The method of claim 12 , wherein the stent graft is deployed in the brachial artery.

14. The method of claim 12 , wherein the stent graft is deployed in the artery of the patient and the stent graft is a branched stent graft.

15. The method of claim 12 , wherein implantation of the vascular access assembly does not involve venous anastomosis.

16. The method of claim 12 , wherein the stent graft is deployed in an arteriovenous graft and the stent graft is an unbranched stent graft.

17. The method of claim 16 , wherein the stent graft, when deployed, forms a fluid-tight seal that diverts the blood from the arteriovenous graft to a flow path that extends to the heart of the patient.

18. The method of claim 12 , wherein deploying the stent graft comprises inflating a balloon to expand to the stent graft.

19. The method of claim 18 , wherein the peripheral end of the second tubular conduit is tunneled through the flesh by passing the peripheral end of the second tubular conduit through a deployment device.

20. The method of claim 12 , wherein the pull string is coupled to filaments surrounding the stent graft in the compressed state.