Assembly of stent grafts

• US 20070043425A1
• Filed: 08/18/2006
• Published: 02/22/2007
• Est. Priority Date: 08/18/2005
• Status: Active Grant

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated), William A. Cook Australia Pty. Ltd (Cook Group Incorporated)
• Inventors: Lawrence-Brown, Michael, Hartley, David
• Granted Patent: US 9,504,555 B2
• Time in Patent Office: Days
• US Class Current: 623/1.120
• CPC Class Codes: A61F 2/07 Stent-grafts
• CPC Class Codes: A61F 2/89 the wire-like elements comprising two or more adjacent rings flexibly connected by separate members
• CPC Class Codes: A61F 2002/061 provided with means for allowing access to secondary lumens
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/9505 having retaining means other than an outer sleeve, e.g. male-female connector between stent and instrument
• CPC Class Codes: A61F 2002/9511 the retaining means being filaments or wires
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0054 V-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

A method of assembling of a stent graft (20) including temporarily diameter reduction arrangements to enable partial release of a stent graft to assist with positioning before complete release. The diameter reduction arrangement includes a release wire (72) and flexible threads (74, 80) extending to struts (76) of a self expanding stent (70) either side of the release wire and being pulled tight. Removal of the release wire enables full expansion of the self expanding stent.

Claims

1. A temporary diameter reduction constraint arrangement for a stent graft, the stent graft comprising a biocompatible graft material tube of a selected diameter and a plurality of self expanding stents fastened thereto, the constraint arrangement comprising at least one release wire extending longitudinally along the graft material tube and at least one circumferential thread engaged around the release wire and a portion of the stent graft circumferentially spaced a selected distance away from the release wire and drawn tight and tied to reduce the circumference and hence the overall diameter of the stent graft.

2. A constraint arrangement as in claim 1 comprising a circumferential thread extending circumferentially in each direction from the release wire.

3. A constraint arrangement as in claim 1 wherein the stents are zig-zag stents comprising struts and bends therebetween and the engagement of the flexible thread into the graft material includes the engagement of the thread around a strut of the self expanding stent.

4. A constraint arrangement as in claim 1 wherein the selected distance is reduced by from 50 to 75%.

5. A constraint arrangement as in claim 1 comprising two release wires and a circumferential thread extending circumferentially in each direction from each of the release wires at a plurality of positions along the release wires to hold the stent graft at a reduced diameter of the stent graft along the length of the stent graft.

6. A method of temporarily reducing the diameter of at least a portion of a self expanding stent graft, the stent graft comprising a tubular body of a biocompatible graft material and a plurality of self expanding stents, the method comprising the steps of;

a) extending a release wire longitudinally along the stent graft and stitching the release wire into the graft material tube;

b) looping a first flexible thread around the release wire and extending the first flexible thread laterally around the circumference of the stent graft to a position a selected distance from the release wire;

c) engaging the first flexible thread into the graft material, and

d) drawing the ends of the thread together and tying ends of the thread,

whereby the selected distance is reduced thereby temporarily reducing the overall diameter of the stent graft.

7. A method as in claim 6 wherein the stents are zig-zag stents comprising struts and bends therebetween and the step of engaging the first flexible thread into the graft material includes engaging the thread around a strut of a self expanding stent.

8. A method as in claim 6 further comprising the steps of;

e) passing a second flexible thread around the release wire and extending the second flexible thread laterally around the circumference of the stent graft in the opposite direction to the first flexible thread to a position a selected distance from the release wire;

f) engaging the second flexible thread into the graft material, and

g) drawing the ends of the second thread together and tying ends of the thread,

whereby the selected distance is reduced thereby reducing the overall diameter of the stent graft.

9. A method in claim 6 wherein the selected distance is reduced by from 50 to 75%.

10. A method as in claim 6 further comprising the steps of;

e) passing a second flexible thread around the around the first flexible thread and extending the second flexible thread laterally around the circumference of the stent graft in the opposite direction to the first flexible thread to a position a selected distance from the release wire;

h) engaging the second flexible thread into the graft material, and

i) drawing the ends of the second thread together and tying ends of the thread,

whereby the selected distance is reduced thereby reducing the overall diameter of the stent graft.

11. A method as in claim 6 further comprising the steps of;

j) extending a second release wire longitudinally along the stent graft parallel to and spaced apart from the first release wire;

k) looping a third flexible thread around the second release wire and extending the third flexible thread laterally around the circumference of the stent graft to a position a selected distance from the second release wire;

l) engaging the third flexible thread into the graft material, and

m) drawing the ends of the thread together and tying ends of the thread,

n) passing a fourth flexible thread around the around the third flexible thread and extending the fourth flexible thread laterally around the circumference of the stent graft in the opposite direction to the third flexible thread to a position a selected distance from the second release wire;

o) engaging the fourth flexible thread into the graft material, and

p) drawing the ends of the fourth thread together and tying ends of the thread,

whereby the selected distance is reduced thereby reducing the overall diameter of the stent graft.

12. A method as in claim 6 comprising applying a plurality of flexible threads to reduce the diameters along the length of the stent graft.

13. A method of temporarily reducing the diameter of at least a portion of a self expanding stent graft, the stent graft comprising a tubular body of a biocompatible graft material and a plurality of self expanding stents, the stents are zig-zag stents comprising struts and bends therebetween, the method comprising the steps of;

a) extending a release wire longitudinally along the stent graft and stitching the release wire into the graft material tube;

b) looping a first flexible thread around the release wire and extending the first flexible thread laterally around the circumference of the stent graft to a selected strut a selected distance from the release wire;

c) engaging the first flexible thread around the selected strut and a portion of the graft material of the stent graft, and

d) drawing the ends of the thread together and tying ends of the thread,

whereby the selected distance is reduced thereby reducing the overall diameter of the stent graft.

14. A method as in claim 13 further comprising the steps of;

e) passing a second flexible thread around the release wire or the around the around the first flexible thread and extending the second flexible thread laterally around the circumference of the stent graft in the opposite direction to the first flexible thread to a position a selected strut selected distance from the release wire;

f) engaging the second flexible thread around a selected strut and a portion of the graft material of the stent graft, and

g) drawing the ends of the second thread together and tying ends of the thread,

whereby the selected distance is reduced thereby reducing the overall diameter of the stent graft.

15. A method in claim 13 wherein the selected distance is reduced by from 50 to 75%.

16. A method as in claim 13 comprising applying a plurality of flexible threads to reduce the diameters along the length of the stent graft.

17. A method as in claim 13 further comprising the steps of;

h) extending a second release wire longitudinally along the stent graft parallel to and spaced apart from the first release wire and stitching the second release wire into the graft material tube;

i) looping a third flexible thread around the second release wire and extending the third flexible thread laterally around the circumference of the stent graft to a position a selected distance from the second release wire;

j) engaging the third flexible thread around a selected strut of the stent graft, and

k) drawing the ends of the thread together and tying ends of the thread,

i) passing a fourth flexible thread around the around the third flexible thread and extending the fourth flexible thread laterally around the circumference of the stent graft in the opposite direction to the third flexible thread to a position a selected distance from the second release wire;

m) engaging the fourth flexible thread around a selected strut of the stent graft, and

n) drawing the ends of the fourth thread together and tying ends of the thread,

thereby reducing the overall diameter of the stent graft.

18. A method as in claim 17 comprising applying a plurality of flexible threads in each circumferential direction from each release wire at a plurality of positions along the release wires to reduce the diameter of the stent graft along the length of the stent graft.

19. A temporarily constraint arrangement for a stent graft, the stent graft comprising a biocompatible graft material tube of a selected diameter and a plurality of self expanding stents fastened thereto, the stents comprising zig-zag stents comprising struts and bends therebetween, the constraint arrangement comprising two release wires extending longitudinally along the graft material tube and substantially parallel to each other, the release wires being stitched into the graft material tube, two threads engaged around each release wire and a selected strut of a stent and portion of the stent graft circumferentially spaced a selected distance away from each release wire in each circumferential direction from the respective release wires and drawn tight to compress the self expanding stent between the selected strut and the release wire and tied to reduce the circumference and hence the overall diameter of the stent graft.