Intravascular device and method for axially stretching blood vessels

• US 20020133223A1
• Filed: 03/07/2002
• Published: 09/19/2002
• Est. Priority Date: 03/09/2001
• Status: Active Grant

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Griffis, Jack C. III, Vito, Raymond P.
• Granted Patent: US 7,018,402 B2
• Time in Patent Office: Days
• US Class Current: 623/1.18
• CPC Class Codes: A61F 2/88 the wire-like elements formed as helical or spiral coils forming a net-like or mesh-like structure A61F2/90
• CPC Class Codes: A61F 2/885 comprising a coil including a plurality of spiral or helical sections with alternate directions around a central axis

Abstract

Intravascular devices and methods are provided for forming a vascular graft by axially distending a blood vessel to induce growth. These devices advantageously can be implanted via a catheter, thereby eliminating the need for a more invasive implantation procedure when the stretching is to be done in vivo. Preferably, the device for axially distending a blood vessel to induce growth of the vessel includes an intravascular stretching mechanism attachable directly to an interior lumen portion of the blood vessel, and a means for operating the stretching mechanism to cause the vessel to distend axially. The stretching mechanism can include a pair of wires or stents that engage the blood vessel wall. Components of the stretching mechanism can include a shape memory material.

Claims

1. A device for axially distending a blood vessel to induce growth of the vessel comprising:

an intravascular stretching mechanism attachable directly to an interior lumen portion of the blood vessel; and

a means for operating the stretching mechanism to cause the vessel to distend axially.

2. The device of claim 1, wherein the intravascular stretching mechanism comprises:

an anchoring wire having a distal end portion; and

a stretching wire having a distal end portion;

wherein the distal end portions are separately anchorable to the interior lumen portion at positions axially remote from one another.

3. The device of claim 2, wherein the distal end portion of the anchoring wire, the distal end portion of the stretching wire, or both, comprise a shape memory material.

4. The device of claim 3, wherein the shape memory material comprises a shape memory alloy or a shape memory polymer.

5. The device of claim 4, wherein the shape memory material comprises a biodegradable shape memory polymer.

6. The device of claim 3, wherein the distal end portion of the stretching wire changes, in response to a change in temperature effective to trigger a change in the shape memory material, from a substantially straight form into a spiral configuration which frictionally engages a first position in the interior lumen portion of the blood vessel when located therein.

7. The device of claim 6, wherein the distal end portion of the anchoring wire changes, in response to a change in temperature effective to trigger a change in the shape memory material, from a substantially straight form into a spiral configuration which engages a second position in the interior lumen portion of the blood vessel when located therein.

8. The device of claim 6, wherein the stretching wire further comprises an intermediary portion which changes, in response to a change in temperature effective to trigger a change in the shape memory material, from a substantially straight form into a helical configuration, said helical configuration being operable as a compression spring.

9. The device of claim 2, further comprising a catheter having at least two lumens extending between a proximal end and a distal end, one of said at least two lumens being suitable for delivering the stretching wire into the interior lumen portion of the blood vessel, and another of said at least two lumens being suitable for delivering the anchor wire into the interior lumen portion of the blood vessel.

10. The device of claim 1, wherein the means for operating comprises a prime mover that is mechanically, electromechanically, or hydraulically driven.

11. The device of claim 1, wherein the means for operating the stretching mechanism causes an axial stretching force to be applied to the vessel in a continuous manner.

12. The device of claim 1, wherein the means for operating the stretching mechanism causes an axial stretching force to be applied to the vessel in an intermittent manner.

13. The device of claim 1, wherein the means for operating the stretching mechanism causes an axial stretching force to be applied to the vessel in a cyclical manner.

14. The device of claim 1, further comprising a controller for controlling the means for operating the stretching mechanism.

15. The device of claim 1, wherein the intravascular stretching mechanism comprises a first stent, a second stent, and a compression spring operably connected to the first stent and the second stent, the first and second stents being separately anchorable to the interior lumen portion at positions axially remote from one another.

16. The device of claim 15, wherein the first stent, the second stent, the compression spring, or a combination thereof, comprises a shape memory material.

17. The device of claim 16, wherein the shape memory material comprises a shape memory alloy or a shape memory polymer.

18. The device of claim 16, wherein the shape memory material comprises a biodegradable shape memory polymer.

19. The device of claim 1, further comprising a therapeutic or prophylactic agent.

20. The device of claim 19, wherein the a therapeutic or prophylactic agent comprises a growth stimulating agent which can be released in an effective amount to enhance growth of the blood vessel.

21. The device of claim 1, wherein all or a portion of the intravascular stretching mechanism is radio-opaque.

22. A method for distending a blood vessel of a human or animal to induce blood vessel growth, comprising the steps:

inserting into an interior lumen portion of a blood vessel the stretching mechanism of the device of claim 1;

anchoring the stretching mechanism to the interior lumen portion at at least two positions axially remote from one another; and

operating the stretching mechanism to axially stretch the blood vessel between said at least two positions over a period of time effective to induce axial growth of the blood vessel.

23. The method of claim 22, wherein the stretching occurs in vivo.

24. The method of claim 22, wherein the stretching occurs in vitro in a medium for cell growth.

25. The method of claim 22, wherein the stretching mechanism is operated to apply an axial stretching force to the vessel in a continuous manner.

26. The method of claim 22, wherein the stretching mechanism is operated to apply an axial stretching force to the vessel in an intermittent manner.

27. The method of claim 22, wherein the stretching mechanism is operated to apply an axial stretching force to the vessel in a cyclical manner.

28. The method of claim 22, wherein the blood vessel is selected from the group consisting of an internal mammary artery, a femoral artery, a gastroepipolic artery, a gastric artery, a radial artery, and a splenic artery.

29. The method of claim 22, wherein the intravascular stretching mechanism comprises an anchoring wire having a distal end portion, and a stretching wire having a distal end portion, wherein the distal end portions are separately anchorable to the interior lumen portion at positions axially remote from one another.

30. The method of claim 22, wherein the intravascular stretching mechanism comprises a first stent, a second stent, and a compression spring operably connected to the first stent and the second stent, the first and second stents being separately anchorable to the interior lumen portion at positions axially remote from one another.

31. The method of claim 22, wherein the anchoring of the stretching mechanism comprises dilating a balloon to cause at least a portion of the stretching mechanism to expand and engage the interior lumen portion of the blood vessel.

32. A method of forming a vascular graft for a human or animal in need thereof, comprising:

distending a donor blood vessel by use of the method of claim 22; and

excising a portion of the distended donor vessel, said portion thereby providing a vascular graft.

33. The method of claim 32, wherein the vessel distension is conducted in vivo.

34. The method of claim 32, wherein the vessel distension is conducted in vitro in a medium for cell growth.

35. The method of claim 32, wherein the donor blood vessel is obtained from a human or transgenic animal.