Low profile, high stretch knit prosthetic device

• US 6,893,457 B2
• Filed: 01/15/2003
• Issued: 05/17/2005
• Est. Priority Date: 07/03/2001
• Status: Expired due to Fees

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Dong, Jerry Q.
• Primary Examiner(s): Jackson, Suzette J.
• Application Number:
  US10/342,971
• Publication Number:
  US 20030149464A1
• Time in Patent Office: 853 Days
• Field of Search: 623 15- 152, 623/1.13, 66192-195
• US Class Current: 623/1.13
• 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 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2002/075 the stent being loosely attached to the graft material, e.g. by stitching
• CPC Class Codes: A61F 2220/0091 connected by a hinged linkage mechanism, e.g. of the single-bar or multi-bar linkage type
• CPC Class Codes: D04B 21/14 Fabrics characterised by the incorporation by knitting, in one or more thread, fleece, or fabric layers, of reinforcing, binding, or decorative threads; Fabrics incorporating small auxiliary elements, e.g. for decorative purposes pile fabrics D04B21/02; non-woven fabrics in general D04H
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents

Abstract

A radially expandable stent-graft endoprosthesis is provided. The graft included in the stent-graft is a knitted tubular structure circumferentially disposed and securably attached to the stent. The knitted tubular structure has a knit pattern of interlacing yarns in an Atlas or a modified-Atlas pattern to provide greater than 150 percent longitudinal stretchability. A knitted tubular graft and a knitted medical fabric with greater than 150 percent longitudinal stretchability are also provided.

Claims

1. An implantable tubular graft comprising:

a tubular knitted graft having a pattern of yarns interlaced into stitches in a knit pattern capable of resilient longitudinal elongation and resilient radial contraction of said graft from a quiescent state to an elongated state;

wherein said knit pattern is a warp knitted pattern of yarns forming a textile layer having an interior surface and an exterior surface, wherein interior yarns form loops in the longitudinal direction of said graft, and exterior yarns are diagonally shifted over one or more of the interior yarns in an alternating pattern along a width of said graft to engage the interior yarns, and further wherein the interior yarn alternately interlaces the engaging exterior yarn to form open loops where the interior yarn does not cross over itself and closed loops where the interior yarn does cross over itself.

2. The graft of claim 1 wherein said knit pattern comprising a interior and exterior yarns interlaced from single stitches, said single stitches being deposed in a plurality of stitch repeating patterns, wherein a first stitch has a repeating pattern traversing diagonally by two or more needle positions and a second stitch has a repeating pattern alternatively traversing diagonally by three or more needle positions and then by one needle position.

3. The graft of claim 1 wherein said yarns are interlaced from about 400 to about 900 stitches per square centimeter to provide compliancy in the quiescent state.

4. The graft of claim 1 wherein said knit pattern is an Atlas or a modified Atlas knit pattern.

5. The graft of claim 1 wherein said knit pattern is a single layer of interlaced yarns.

6. The graft of claim 1 wherein said graft has a wall thickness of at least about 0.3 millimeters.

7. The graft of claim 1 wherein said graft has a wall thickness no more than about 0.4 millimeters.

8. The graft of claim 1 further including a tubular layer of PTFE circumferentially disposed and securably attached to said graft.

9. The graft of claim 8 wherein said tubular layer of PTFE is a tubular layer of ePTFE.

10. The graft of claim 1 wherein said yarns are selected from the group consisting of monofilament yarns, multifilament yearns, spun type yarns, flat yarns, twisted yarns, textured yarns, and combinations thereof.

11. The graft of claim 1 wherein said yarns are selected from the group of materials selected from polyesters, polypropylenes, polyethylenes, polyurethanes, polytetrafluoroethylenes or combinations thereof.

12. The graft of claim 11 wherein said polyesters include polyethylene terephthalate polyesters.

13. An implantable tubular graft comprising:

a tubular knitted tubular graft having a pattern of yarns interlaced into stitches in a knit pattern capable of resilient longitudinal elongation and resilient radial contraction of said graft from a quiescent state to an elongated state and having greater than about 350 stitches per square centimeter to provide compliancy in the quiescent state;

wherein the elongated length is at least 50 percent by length greater than the quiescent length.

14. The graft of claim 13 wherein said knit pattern is a warp knitted pattern of yarns forming a textile layer having an interior surface and an exterior surface, wherein interior yarns form loops in the longitudinal direction of said graft, and exterior yarns are diagonally shifted over one or more of the interior yarns in an alternating pattern along a width of said graft to engage the interior yarns, and further wherein the interior yarn alternately interlaces the engaging exterior yarn to form open loops where the interior yarn does not cross over itself and closed loops where the interior yarn does cross over itself.

15. The graft of claim 13 wherein said yarns are interlaced from about 400 to about 900 stitches per square centimeter to provide compliancy in the quiescent state.

16. The graft of claim 13 wherein said knit pattern is an Atlas or a modified Atlas knit pattern.

17. The graft of claim 13 wherein said knit pattern is a single layer of interlaced yarns.

18. The graft of claim 13 wherein said graft has a wall thickness of at least about 0.3 millimeters.

19. The graft of claim 13 wherein said graft has a wall thickness no more than about 0.4 millimeters.

20. The graft of claim 13 further including a tubular layer of PTFE circumferentially disposed and securably attached to said graft.

21. The graft of claim 20 wherein said tubular layer of PTFE is a tubular layer of ePTFE.

22. The graft of claim 13 wherein said yarns are selected from the group consisting of monofilament yarns, multifilament yearns, spun type yarns, flat yarns, twisted yarns, textured yarns, and combinations thereof.

23. The graft of claim 13 wherein said yarns are selected from the group of materials selected from polyesters, polypropylenes, polyethylenes, polyurethanes, polytetrafluoroethylenes or combinations thereof.

24. The graft of claim 23 wherein said polyesters include polyethylene terephthalate polyesters.

25. An implantable tubular graft comprising:

a tubular graft having a pattern of yarns formed into in a textile pattern capable of resilient longitudinal elongation and resilient radial contraction of said graft from a quiescent state to an elongated state;

wherein said textile pattern is a single textile layer having an interior surface and an exterior surface, wherein interior yarns predominate the interior surface and form loops in the longitudinal direction of said graft, and exterior yarns predominate the exterior surface and are diagonally shifted over one or more of the interior yarns in an alternating pattern along a width of said graft before engaging the interior yarns.

26. An implantable device comprising:

a textile structure having a pattern of yarns interlaced into stitches in a knit pattern capable of resilient longitudinal expansion from a quiescent state and having at least about 400 stitches per square centimeter and further having no more than about 900 stitches per square centimeter to provide compliancy for the structure;

wherein said knit pattern is a warp knitted pattern of yarns forming a textile layer having a first surface and a second opposed surface, wherein a first yarn predominates the first surface and forms loops in the longitudinal direction of said fabric, and a second yarn predominates the second surface and is diagonally shifted over one or more of the first yarns in an alternating pattern along a width of said fabric to engage the first yarn, and further wherein the second yarn alternately interlaces the engaging first yarn to form an open loop where the second yarn does not cross over itself and a closed loop where the second yarn does cross over itself, and further wherein said textile structure is a tubular graft structure or a medical fabric structure.

27. A knitted medical fabric comprising:

a knitted structure having a pattern of yarns interlaced into stitches in a knit pattern capable of resilient longitudinal expansion from a quiescent state and having at least about 400 stitches per square centimeter and further having no more than about 900 stitches per square centimeter to provide compliancy for the structure;

wherein said knit pattern is a warp knitted pattern of yarns forming a textile layer having a first surface and a second opposed surface, wherein a first yarn predominates the first surface and forms loops in the longitudinal direction of said fabric, and a second yarn predominates the second surface and is diagonally shifted over one or more of the first yarns in an alternating pattern along a width of said fabric to engage the first yarn, and further wherein the second yarn alternately interlaces the engaging first yarn to form an open loop where the second yarn does not cross over itself and a closed loop where the second yarn does cross over itself.

28. The medical fabric of claim 27 wherein said first and second yarns are formed from single stitches, said single stitches being deposed in a plurality of stitch repeating patterns, wherein a first stitch has a repeating pattern traversing diagonally by two or more needle positions and a second stitch has a repeating pattern alternatively traversing diagonally by three or more needle positions and then by one needle position.

29. The medical fabric of claim 27 wherein said yarns are polyethylene terephthalate polyester textured yarns having a denier of at least about 30;

and further wherein said polyethylene terephthalate polyester textured yarns having a denier of no more than about 100.