FLEXIBLE EXPANDABLE STENT

Abstract

A flexible, expandable stent assembly comprised of a generally cylindrically shaped channel, having a longitudinal axis, and having a plurality of openings therein. The openings are defined by longitudinally aligned circumferential arrays of generally “hairpin-like curved web arrays or bends of metal, creating a plurality of circumferentially disposed “Palm Tree” shaped annular spaces between longitudinally adjacent web arrays.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The objects and advantages of the present invention will become more apparent when viewed in conjunction with the following drawings, in which:

FIG. 1 is a longitudinal presentation, in a flat or “planar” array, of a stent assembly in an embodiment of the present invention;

FIG. 1A is an enlarged view, in plan, of a portion of a circumferential array of arcuately shaped hairpin-like bends of the stent assembly shown in FIG. 1;

FIG. 2A is a side elevational view of a stent assembly in an embodiment of the present invention in a cylindrical configuration;

FIG. 2B is a perspective view of the stent assembly of FIG. 2A, again in a cylindrical configuration; and

FIG. 3 is a perspective view of two stent assemblies in accordance with an embodiment of the present invention shown interdigitated in a vessel bifurcation.

Claims

1. A flexible, expandable, elongated stent assembly comprised of a generally cylindrically shaped channel, having a longitudinal axis, and having a plurality of openings therein, said openings being defined by a structure of longitudinally aligned circumferential arrays of arcuately shaped, generally hairpin-like smoothly curved webs or bends.

2. The flexible, expandable stent assembly as recited in claim 1, wherein each of said circumferential array of webs is comprised of a first pattern of lengthwise sized bends and a second pattern of lengthwise-elongatedly sized bends at regular intervals on each circumferential array.

3. The flexible, expandable stent assembly as recited in claim 2, wherein the regular intervals of a second pattern of lengthwise-elongated sized bends consists of every third bend-position on at least one longitudinal side of said each circumferential array.

4. The flexible, expandable stent assembly as recited in claim 1, wherein a substantial portion of each of said arcuately shaped, generally hairpin-like curved webs or bends form arcs of generally the same orientation with respect to the circumference of said stent assembly.

5. The flexible, expandable stent assembly as recited in claim 1, wherein longitudinally adjacent arrays of generally arcuately shaped hairpin-like curved bends or webs are connected to one another by a cross-link arrangement connected to diagonally disposed bends of said longitudinally adjacent arrays of bends or webs.

6. The flexible, expandable stent assembly as recited in claim 5, wherein said diagonally disposed bends are diagonally adjacent.

7. The flexible, expandable stent assembly as recited in claim 6, wherein said cross-link arrangement between longitudinally adjacent arrays consists of two or more cross-links connecting each adjacent array

8. The flexible, expandable stent assembly as recited in claim 8 wherein said two or more cross-links connecting each adjacent arrays consists of two cross-links.

9. The flexible, expandable stent assembly as recited in claim 7 wherein each of said cross-links extends from a mid-portion of a longitudinally extending curved section of a bend to the tip portion of a bend of a longitudinally adjacent array.

10. The flexible, expandable stent assembly of claim 9 wherein the connection of said cross-link to said tip portion of a bend of a longitudinally adjacent array generally smoothly extends the arcuate curvature of said bend of a longitudinally adjacent array.

11. The flexible, expandable stent assembly as recited in claim 7, wherein said cross-links are connected between lengthwise-elongated sized bends of said adjacent arrays.

12. The flexible, expandable stent assembly as recited in clam 11, wherein said cross-links are spaced generally diagonally adjacent one another between said longitudinally adjacent arrays of bends.

13. The flexible, expandable stent assembly as recited in claim 7, wherein a circumferential gap or open cell is arranged between circumferentially adjacent cross-links is, in a flattened radially directed view, generally of a “Palm Tree” shape so as to promote smooth expansion and proper bending of said stent assembly in the vasculature of a being.

14. The flexible, expandable stent assembly as recited in claim 1, wherein said assembly has a substrate surface comprised of a cobalt-chromium alloy.

15. The flexible, expandable stent assembly as recited in claim 1, wherein said assembly comprises a substrate with a thickness of between about 60 and 100 microns.

16. The flexible, expandable stent assembly as recited in claim 1, wherein said assembly comprises a substrate with a thickness of between about 50 and 80 microns.

17. The flexible, expandable stent assembly as recited in claim 1, wherein said assembly comprises a substrate with a thickness of between about 110 and 150 microns.

18. The flexible, expandable stent assembly as recited in claim 1, wherein said assembly has a substantially biocompatible surface layer thereon.

19. The flexible, expandable stent assembly as recited in claim 18, wherein said bio-compatible surface layer comprises a substantially biocompatible metal.

20. The flexible, expandable stent assembly as recited in claim 19, wherein said substantially biocompatible metal is selected from the group consisting of platinum, gold, and silver.

21. The flexible, expandable stent assembly as recited in claim 18, wherein said bio-compatible surface layer comprises graduated sub-layers incorporating metals adhesive to the substrate surface of said stent.

22. The flexible, expandable stent assembly as recited in claim 21, wherein said sub-layers include an adhesion layer comprised substantially of palladium, a transition layer in which the ratio of palladium content is gradually decreased and the ratio of platinum content is gradually increased, with an outermost layer comprised substantially of platinum.

23. The flexible, expandable stent assembly as recited in claim 19, wherein said bio-compatible surface layer has a thickness of between 100 angstroms and about 5000 angstroms.

24. The flexible, expandable stent assembly as recited in claim 23, wherein said bio-compatible surface layer has a thickness of no greater than 2500 angstroms.

25. The flexible, expandable stent assembly as recited in claim 19, wherein said biocompatible surface layer is implanted onto said stent assembly using the method of: ion-bombardment.

26. A stent assembly for implantation into a human vessel, comprised of an elongated collection of circumferentially extending smoothly curved arcuately shaped hairpin-like curves or webs, each of said circumferentially extending curved webs being in generally corresponding alignment with one another.

27. The stent assembly as recited in claim 26, wherein a substantial portion of each of said arcuately shaped, hairpin-like curves or webs forms an arc of generally the same orientation with respect to the circumference of said stent assembly.

28. The stent assembly as recited in claim 26, wherein each of said circumferentially extending curved webs of hairpin-like curves are adjacently connected by at least two cross-links.

29. The stent assembly as recited in claim 26, wherein each of said cross-links are arranged diagonally across from one another, between adjacent circumferentially extending curved webs.

30. The stent assembly as recited in claim 28, wherein a generally “Palm Tree” shaped arcuate gap is arranged between longitudinally adjacent circumferentially extending curved webs and between circumferentially adjacent cross-links.

31. The stent assembly as recited in claim 26, wherein each of said circumferentially extending curved web consists of at least two sets of hairpin-like curves each of which is comprised of a pair of a longitudinally short first bend hairpin-like members separated by a single longitudinally elongated second hairpin-like bend member.

32. The stent assembly as recited in claim 31, wherein said cross-links connecting said longitudinally adjacent circumferentially extending curved webs are attached between diagonally adjacent second bend members on longitudinally adjacent circumferentially curved webs.

33. A method of stenting a bifurcated vessel of a patient comprising: placing a first stent assembly into said vessel at its vessel bifurcation, and into a first arm of said vessel bifurcation;placing a second stent assembly into said first stent assembly in said vessel; anddirecting said second stent assembly at least partway through a generally circumferentially elongatedly extending opening in a side wall portion of said first stent assembly and into a second arm of said vessel bifurcation, said first and second stent assemblies each having a longitudinal axis and having a plurality of openings therein, said openings being defined by a structure of longitudinally aligned circumferential arrays of smoothly curved arcuately shaped, generally hairpin-like first and second pattern of webs or bends.

34. The method of stenting a bifurcated vessel as recited in claim 33 wherein said circumferentially elongatedly extending openings are of generally a “Palm Tree” shape as viewed from a flattened radially directed perspective.

35. The method of stenting a bifurcated vessel as recited in claim 33 wherein said second pattern of webs or bends are longitudinally longer than said first pattern of webs or bends.

36. The method of stenting a bifurcated vessel as recited in claim 33 wherein said second pattern of webs or bends are connected by a cross-link between a longitudinally adjacent second pattern of webs.

37. The method of stenting a bifurcated vessel as recited in claim 33 wherein said cross-link is arcuately shaped in a manner that generally smoothly extends the arcuate curvature of said longitudinally adjacent second pattern of webs.

38. The method of stenting a bifurcated vessel as recited in claim 33, including: leaving at least a portion of said second stent assembly within and in fluid communication with said first stent assembly at said bifurcation.

39. The method of stenting a bifurcated vessel as recited in claim 33, including: inserting said first stent assembly and said second stent assembly into a body vessel, simultaneously.

40. The method of stenting a bifurcated vessel as recited in claim 39, including: overlapping a longitudinal portion of said second stent assembly with a longitudinal portion of said first stent assembly during their simultaneous introduction into a body vessel.

41. The method of stenting a bifurcated vessel as recited in claim 33, including: directing a distal portion of said second stent assembly through a circumferential gap in said first stent assembly subsequent to said first stent assembly and said second stent assembly being simultaneously introduced into a body vessel.

42. A flexible, expandable stent assembly for stenting of a bifurcation in a body vessel, comprising: a first generally cylindrically shaped channel, having a longitudinal axis, and having a plurality of openings therein, said openings being defined by longitudinally aligned circumferential arrays of arcuately shaped, generally hairpin-like smoothly curved webs or bends of metal; anda second generally cylindrically shaped channel, having a longitudinal axis, and having a plurality of openings therein, said openings being defined by longitudinally aligned circumferential arrays of arcuately shaped, generally hairpin-like smoothly curved webs or bends of metal, said second generally cylindrically shaped channel extending at least partially longitudinally within said first generally cylindrically shaped channel.

43. The flexible, expandable stent assembly as recited in claim 42, wherein said second generally cylindrically shaped channel is of a smaller diameter than said first generally cylindrically shaped channel.

44. The flexible, expandable stent assembly as recited in claim 42, wherein said second generally cylindrically shaped channel is of a shorter length than said first generally cylindrically shaped channel.

45. The flexible, expandable stent assembly as recited in claim 42, wherein said second generally cylindrically shaped channel is of a smaller diameter and is of a shorter length than said first generally cylindrically shaped channel.

46. A method of substantially preventing foreshortening in an expandable, body lumen insertable stent assembly, comprising: expanding radially outwardly a plurality of longitudinally connected annular arrays of hairpin-like shaped webs of first length bends and second elongated-length bends of metal,connecting said annular arrays of hairpin-like shaped webs by at least two cross-links spaced between a pair of said second elongated-length bends arranged in neighboring arrays of said annular arrays of webs; andre-orienting said first length bends and second elongated-length bends as said stent assembly expands within a body lumen to substantially maintain the original body length of said stent assembly.

47. The method as recited in claim 46, including: re-orienting a cross-link disposed between said neighboring second elongated-length bends.

48. The method as recited in claim 46, wherein said first length and second elongated-length bends and said cross-links are correspondingly smoothly curved.

49. A method for longitudinally extending a stent assembly, said method comprising the steps of: providing first and second generally cylindrically shaped channels, each having a longitudinal axis, and each having a plurality of openings therein, said openings being defined by longitudinally aligned circumferential arrays of arcuately shaped, generally hairpin-like smoothly curved webs or bends of metal; andinserting a longitudinal end of said first channel into a longitudinal end of said second channel so that the longitudinal ends partially overlap.

50. The method of claim 49 wherein, prior to the step of inserting a longitudinal end of said first channel into a longitudinal end of said second channel, said first channel is deployed within a vessel.

51. The method of claim 49 wherein, after the step of inserting a longitudinal end of said first channel into a longitudinal end of a second channel, said channels are simultaneously deployed within a vessel.