Endoluminal prosthesis placing method

• US 20010020173A1
• Filed: 04/04/2001
• Published: 09/06/2001
• Est. Priority Date: 02/26/1999
• Status: Active Grant

• Current Assignee: LeMaitre Vascular, Incorporated
• Original Assignee: Vascular Architects Incorporated
• Inventors: Fogarty, Thomas J., Klumb, Katherine J., Hill, Bradley B., Kamdar, Kirti P.
• Granted Patent: US 6,488,700 B2
• Time in Patent Office: Days
• US Class Current: 606/194
• CPC Class Codes: A61F 2/07 Stent-grafts
• 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 2/954 for placing stents or stent-grafts in a bifurcation
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/065 Y-shaped blood vessels
• CPC Class Codes: A61F 2002/067 modular
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2002/9511 the retaining means being filaments or wires
• CPC Class Codes: A61F 2220/005 using adhesives
• CPC Class Codes: A61F 2220/0058 soldered or brazed or welded
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0039 differing in diameter

Abstract

A catheter assembly includes a coiled endoluminal prosthesis (122, 190, 198) and a catheter (136) having at least first and second telescoping shafts (138, 140, 142). The prosthesis is releasably engaged to the distal ends (144, 146, 148) of the telescoping shafts. The prosthesis is capable of assuming a second, expanded diameter state from a first, reduced diameter state. The length and number of turns (128) of the coiled prosthesis can be changed by the relative translation and rotation of the shafts. The catheter assembly is especially useful for placing a coiled stent graft (122), in which one turn (132, 134) of the prosthesis has a greater pitch than the adjacent turns, at the intersection (184) of a bifurcation within a blood vessel (182). Remotely viewable marker elements (188, 190, 191, 192, 193, 195, 197) may be used and include a marker element (193, 190A, 197) configured to indicate orientation as well as axial position of the prosthesis. The ends of the prosthesis may be substantially less stiff than the remainder of the prosthesis and/or shaped to help prevent tissue trauma.

Claims

1. A catheter assembly comprising:

a catheter comprising first and second rotatable, telescoping shafts having first and second prosthesis portion holders, respectively;

an endoluminal prosthesis, capable of assuming a second, expanded-diameter state from a first, reduced-diameter state; and

the prosthesis having first and second prosthesis portions releasably engageable with the first and second prosthesis portion holders, respectively.

2. The catheter assembly according to

claim 1

wherein:

the first and second shafts have distal end portions, the first and second prosthesis portion holders at said distal end positions; and

the endoluminal prosthesis at least partially surrounds the distal end portions.

3. The catheter assembly according to

claim 1

wherein the prosthesis comprises a coiled prosthesis, said prosthesis having a plurality of turns and a generally helical gap defined between said turns, whereby the prosthesis length and the number of turns of the coiled prosthesis can be changed by the relative longitudinal and rotary motion of the shafts.

4. The catheter assembly according to

claim 3

wherein:

the catheter further comprises a third telescoping and rotatable shaft having a third prosthesis portion holder; and

the prosthesis has a third prosthesis portion releasably engageable with the third prosthesis portion holder.

5. The catheter assembly according to

claim 4

wherein the second shaft is housed between the first and third shafts.

6. The catheter assembly according to

claim 4

wherein:

the pitch of at least one turn at the second prosthesis portion is greater than the pitch of adjacent turns so to promote substantially unrestricted fluid flow between a

first vessel housing the prosthesis and a branching vessel when the second prosthesis portion is at an intersection of the first and branching vessels; and

the second prosthesis portion is at a central region of the stent graft.

7. The catheter assembly according to

claim 4

wherein the first and third prosthesis portions assume different diameters when the prosthesis is in the second, expanded-diameter state so to accommodate a change in vessel diameter.

8. The catheter assembly according to

claim 1

wherein the prosthesis comprises a series of spaces, at least one of the spaces being substantially larger than an adjacent space to promote substantially unrestricted fluid flow between a first vessel housing the prosthesis and a branching vessel when the second prosthesis portion is at an intersection of the first and branching vessels.

9. The catheter assembly according to

claim 1

wherein the prosthesis comprises a coiled stent graft, said stent graft having a plurality of turns and a generally helical gap defined between said turns.

10. The catheter assembly according to

claim 9

wherein the coiled stent graft is a self-expanding coiled stent graft.

11. The catheter assembly according to

claim 9

wherein the pitch of at least one turn at the second prosthesis portion is greater than the pitch of adjacent turns so to promote substantially unrestricted fluid flow between a first vessel housing the prosthesis and a branching vessel when the second prosthesis portion is at an intersection of the first and branching vessels.

12. The catheter assembly according to

claim 11

wherein the second prosthesis portion is at an end of the coiled stent graft.

13. The catheter assembly according to

claim 11

wherein:

the catheter shaft further comprises a third telescoping and rotatable shaft having a third prosthesis portion holder; and

the stent graft has a third prosthesis portion releasably engageable with the third prosthesis portion holder.

14. The catheter assembly according to

claim 13

wherein the second shaft is housed between the first and third shafts.

15. The catheter assembly according to

claim 13

wherein the second prosthesis portion is at a central region of the stent graft.

16. The catheter assembly according to

claim 13

further comprising first, second and third remotely viewable marker elements at spaced-apart positions on the second prosthesis portion of the stent graft so to aid proper placement of said second prosthesis portion at the intersection of the first and branching vessels.

17. The catheter assembly according to

claim 1

further comprising a remotely viewable marker on at least one of the second prosthesis portion holder and the second portion of the prosthesis to aid placement of the prosthesis at an intersection of a branching vessel with a first vessel.

18. The catheter assembly according to

claim 17

wherein the marker is an orientation marker so to provide information on both position and orientation of the second prosthesis portion.

19. The catheter assembly according to

claim 1

wherein the prosthesis comprises a coiled stent.

20. The catheter assembly according to

claim 19

wherein said distal end portions are substantially less stiff than the remainder of the coiled stent.

21. The catheter assembly according to

claim 20

wherein said distal end portions each have an inwardly-tapering portion with a blunt tip, a longitudinally-extending length and a laterally-extending width, said length greater than said width.

22. The catheter assembly according to

claim 19

wherein said distal end portions each have an inwardly-tapering portion with a blunt tip and a longitudinally-extending length and a laterally-extending width, the length greater than the width.

23. The catheter assembly according to

claim 19

wherein said coiled stent has first, second and third longitudinal sections each having a different radial stiffness.

24. The catheter assembly according to

claim 19

wherein the coiled stent comprises a coiled ribbon of material with its width substantially greater than its thickness.

25. The catheter assembly according to

claim 24

further comprising a tubular graft material surrounding the coiled ribbon of material to create a coiled stent graft in which adjacent turns define gaps therebetween.

26. The catheter assembly according to

claim 25

wherein the gaps and the turns of the coiled stent graft both have average longitudinal dimensions, the average longitudinal dimension of said gaps being about 0% to 1200% of the average longitudinal dimension of the turns of the coiled stent graft.

27. The catheter assembly according to

claim 26

wherein the average longitudinal dimension of the gaps is about 50% to 800% of the average longitudinal dimension of the turns of the coiled stent graft.

28. The catheter assembly according to

claim 24

wherein the coiled ribbon of material has edge elements separated by connector elements.

29. A catheter assembly comprising:

a catheter comprising first and second rotatable, telescoping shafts having first and second prosthesis portion holders, respectively, said first shaft being a tubular shaft housing said second shaft therein;

a coiled endoluminal prosthesis, having a plurality of turns and a generally helical gap defined between said turns, capable of assuming a second, expanded-diameter state from a first, reduced-diameter state;

the prosthesis having first and second prosthesis portions releasably engageable with the first and second prosthesis portion holders, respectively;

whereby the length and the number of turns of the coiled endoluminal prosthesis can be changed by relative longitudinal and rotary motion of the shafts.

30. A method for placing an endoluminal prosthesis within a body comprising:

introducing the distal portion of a catheter assembly at a chosen position within a body, the distal catheter portion comprising a coiled endoluminal prosthesis would about a catheter shaft, the prosthesis having a plurality of turns and being capable of assuming a second, expanded-diameter state from a first, reduced-diameter state, said turns having spaces therebetween when in the second state, the pitch of at least one turn being greater than the pitch of adjacent turns when in the second state, the prosthesis releasably connected to the catheter shaft at a first position along the prosthesis at the at least one turn and at a second position along the prosthesis, the second position being spaced-apart from the first position;

locating said at least one turn at an intersection of a first vessel and a branching vessel;

releasing the prosthesis from the catheter;

maintaining the first position of the prosthesis at the intersection; and

the locating and maintaining steps being carried out so to keep the intersection substantially unobstructed to enhance fluid flow between the first and branching vessels with the prosthesis in its second, expanded-diameter state.

31. The method according to

claim 30

wherein said introducing step is carried out with said at least one turn being at an end of said prosthesis.

32. The method according to

claim 30

wherein:

the introducing step is carried out with said at least one turn being at a central portion of said prosthesis, the second position and a third position along the prosthesis being on opposite sides of the first position;

the introducing step is carried out using a catheter shaft comprising outer, intermediate and inner rotatable, telescoping shafts releasably connected to the second, first and third positions, respectively; and

the remainder releasing step is carried out by releasing the third position and then the first position from the catheter shaft.

33. The method according to

claim 30

wherein the releasing step comprises:

releasing the second position of the prosthesis from the catheter permitting at least a portion of the prosthesis to detach; and

releasing the remainder of the prosthesis, including the first position, from the catheter shaft permitting the remainder of the prosthesis to detach.

34. The method according to

claim 30

wherein the introducing step is carried out using a catheter shaft comprising first and second rotatable, telescoping shafts, said first and second positions of the prosthesis releasably connected to the first and second telescoping shafts, respectively.

35. The method according to

claim 34

further comprising the step of longitudinally moving at least one the first and second telescoping shafts relative to one another to selectively adjust the length of the prosthesis.

36. The method according to

claim 35

further comprising the step of rotating at least one of the first and second telescoping shafts relative to one another to selectively adjust the number of turns of the prosthesis.

37. A method for placing an endoluminal prosthesis within a body comprising:

introducing the distal portion of a catheter assembly at a chosen position within a body, the distal catheter portion comprising a coiled endoluminal prosthesis wound about first and second rotatable, telescoping shafts, the prosthesis having a plurality of turns and being capable of assuming a second, expanded-diameter state from a first, reduced-diameter state, said turns having spaces therebetween when in the second state, the prosthesis releasably connected to the first and second shafts at first and second positions along the prosthesis, the second position being spaced-apart from the first position;

locating said prosthesis at a target site;

selectively adjusting the number of turns of the prosthesis by rotating at least one of the shafts relative to one another;

selectively adjusting the length of the prosthesis by longitudinally moving at least one of the shafts relative to one another;

releasing the prosthesis from the shafts; and

removing the shafts from the body.

38. The method according to

claim 37

wherein said introducing step is carried out with said first and second positions at distal ends of said prosthesis and releasably connected to distal ends of the first and second shafts.

39. The method according to

claim 37

wherein the releasing step comprises:

releasing the second position of the prosthesis from the second shaft permitting at least a portion of the prosthesis to expand; and

releasing the first position of the prosthesis from the first shaft permitting the remainder of the prosthesis to expand.

40. The method according to

claim 37

wherein the selectively adjusting steps are carried out so that the prosthesis is placed in its expanded-diameter state prior to the releasing step so that the proper placement of the prosthesis can be confirmed prior to said releasing step.