RETRIEVABLE BLOOD CLOT FILTER

Abstract

A compact retrievable blood clot filter has a filter section, a releasable lock and an alignment section connected to the filter section. Alignment ribs of the alignment section have releasable upstream ends that are locked to the filter by the releasable lock. The releasable upstream ends of the alignment ribs are capable of being released from the releasable lock so that during retrieval of the filter, the alignment ribs can slide through the endothelial tissue that may have grown around the alignment ribs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is plan view of one exemplary embodiment of the vena cava filter device in an expanded state according to the present invention.

FIG. 2 is an enlarged downstream end view of the expanded vena cava filter device as illustrated in FIG. 1 according to the present invention.

FIG. 3 is an illustration of the vena cava filter device in a non-expanded or collapsed state according to the present invention.

FIG. 4 is an exploded perspective view depicting the assembly of the components of the vena cava filter of the present invention.

FIG. 5A is an enlarged partial view of the alignment section and secondary filtering hub prior to attachment according to the present invention.

FIG. 5B is an enlarged partial view of the alignment section and secondary filtering hub after assembly depicting the interlocking relationship between the alignment section and the secondary filtering hub.

FIG. 6A illustrates an enlarged partial plan view of the alignment ribs positioned within and being restrained within the primary filtering hub after final assembly.

FIG. 6B is an enlarged partial cross-sectional view of FIG. 6A taken along lines A-A.

FIG. 7 is a series of cross-sectional partial views of an alignment rib within the filtering hub illustrating the enlarged circled area of FIG. 6B.

FIG. 7A is a partial cross-sectional view of an alignment rib within the filtering hub prior to disengagement.

FIG. 7B is a partial cross-sectional view of an alignment rib during the first step of retrieval as force is applied to the upstream segment of the alignment rib.

FIG. 7C is a partial cross-sectional view of an alignment rib as additional force is applied and the alignment rib begins to disengage.

FIG. 7D is a partial cross-sectional view of an alignment rib after it has been released from the receiving pocket of the secondary filtering hub.

FIG. 8 is a side view of the filter device in a deployed state inside a vessel with a snare device attached to tile hook of the filter device before retrieval, according to the present invention.

FIG. 9A is a plan view of the filter device with the alignment ribs partially collapsed and partially covered by endothelial tissue overgrowth at the alignment rib contact portion as the retrieval sheath is advanced over the alignment ribs, according to the present invention.

FIG. 9B is an enlarged view of the circled area of FIG. 9A.

FIG. 10A is a plan view of the filter device, illustrating the retrieval sheath being advanced further into the vessel, thereby exerting pressure against the alignment ribs and causing the endothelial overgrowth covering the alignment rib contact portion to cinch inward toward the filter, according to the present invention.

FIG. 10B is an enlarged view of the circled area of FIG. 10A.

FIG. 11A is a plan view of the filter device, illustrating the alignment ribs spontaneously releasing from the filtering section, the alignment rib contact portion spontaneously releasing from the endothelial tissue overgrowth as the retrieval sheath is advanced toward the free ends of the alignment ribs, and the wall-engaging ends releasing from the vessel wall, according to the present invention.

FIG. 11B is an enlarged view of the circled area of FIG. 11A.

FIG. 12 is a plan view of the partially collapsed filter device inside of the vessel, according to the present invention.

FIG. 13 is a plan view of the filter device in a completely collapsed state inside the retrieval sheath before being removed from the vessel.

FIG. 14 is a plan view of an alternative embodiment of the retrievable filter device of FIG. 1.

FIGS. 15A and 15B are plan views of alternative embodiments of the releasable lock and releasable upstream ends of the alignment ribs.

Claims

1. A retrievable blood clot filter comprising: a filter section having a plurality of filter legs;a releasable lock; andan alignment section coupled to the filter section, the alignment section having a plurality of alignment ribs having releasable upstream ends locked by the releasable lock, the releasable lock capable of releasing at least one releasable upstream end of the alignment ribs.

2. The retrievable blood clot filter according to claim 1, wherein the releasable lock is adapted to release at least one releasable upstream end of the alignment ribs during retrieval of the retrievable blood clot filter.

3. The retrievable blood clot filter according to claim 1, wherein the releasable lock includes a plurality of recesses each receiving a corresponding releasable upstream end of the alignment ribs.

4. The retrievable blood clot filter according to claim 3, wherein: each releasable upstream end includes at least one projecting surface; andeach recess includes at least one retaining surface facing the at least one projecting surface and retains the each releasable upstream end of the alignment ribs.

5. The retrievable blood clot filter according to claim 1, wherein the releasable lock includes a cover piece that covers at least a portion of the releasable upstream ends of all of the alignment ribs in a circumferential direction to prevent the release of the releasable upstream ends during a filtering operation of the filter.

6. The retrievable blood clot filter according to claim 5, wherein the cover piece includes biodegradable material which biodegrades over time.

7. The retrievable blood clot filter according to claim 1, wherein the releasable upstream end of the alignment ribs includes biodegradable material which biodegrades over time.

8. The retrievable blood clot filter according to claim 1, wherein the releasable upstream end of the alignment ribs includes a structurally weakened portion to reduce the force required to release the releasable upstream end from the releasable lock.

9. The retrievable blood clot filter according to claim 1, wherein the releasable upstream end of the alignment ribs is coupled to the releasable lock by an interference friction fit.

10. The retrievable blood clot filter according to claim 9, wherein the releasable lock is capable of releasing the at least one releasable upstream end of the alignment ribs in response to a longitudinal force applied to the at least one releasable upstream end.

11. The retrievable blood clot filter according to claim 1, further comprising a shaft coupled to both the alignment section and the filter section, and positioned along a longitudinal axis of the alignment section.

12. The retrievable blood clot filter according to claim 11, wherein: the filter section includes a filter hub from which the filter legs extend; andthe shaft is slidably coupled to the filter hub.

13. The retrievable blood clot filter according to claim 11, wherein: the filter section includes a filter hub from which the filter legs extend;the shaft is slidably coupled to the filter hub; andthe shaft includes a stop member adapted to prevent the filter section from separating from the alignment section when the at least one releasable upstream end of the alignment ribs is released from the releasable lock.

14. The retrievable blood clot filter according to claim 11, wherein the shaft includes a flexible shaft or a wire.

15. The retrievable blood clot filter according to claim 1, wherein the filter section comprises: a filter hub from which the filter legs extend;a plurality of second filter legs each including first and second branch legs that extend radially outwardly from a branch point upstream of the filter hub.

16. The retrievable blood clot filter according to claim 15, wherein the filter legs are alternately disposed with the second filter legs in a circumferential direction.

17. The retrievable blood clot filter according to claim 15, wherein: the upstream end of at least some of the filter legs includes a wall engaging barb generally pointed in the downstream direction; andthe upstream end of each second filter leg has a smooth profile relative to the upstream end of each filter leg and is adapted to rest on a vessel wall.

18. The retrievable blood clot filter according to claim 1, wherein the alignment section is longitudinally spaced from the filter section in a non-overlapping manner.

19. A retrievable blood clot filter comprising: a conical filter section having a filter hub and a plurality of filter legs having downstream ends coupled to the hub and upstream ends that extend radially outwardly;a releasable lock coupled to the filter hub; andan alignment section coupled to the conical filter section, the alignment section having an alignment hub and a plurality of alignment ribs having downstream ends coupled to the alignment hub and releasable upstream ends locked by the releasable lock, the alignment ribs extending radially outwardly from the downstream ends and then further extending radially inwardly, wherein the releasable lock is capable of releasing at least one releasable upstream end of the alignment ribs in response to a force applied to the at least one releasable upstream end of the alignment ribs during retrieval of the retrievable blood clot filter; anda shaft coupled to the alignment hub and the filter hub.

20. The retrievable blood clot filter according to claim 19, wherein the releasable lock is adapted to release the at least one releasable upstream end of the alignment ribs in response to a radially outward force applied to the at least one releasable upstream end.

21. The retrievable blood clot filter according to claim 19, wherein the releasable lock includes a plurality of recesses each receiving a corresponding releasable upstream end of the alignment ribs.

22. The retrievable blood clot filter according to claim 21, wherein: each releasable upstream end includes at least one projecting surface; andeach recess includes at least one retaining surface facing the at least one projecting surface and retains the each releasable upstream end of the alignment ribs.

23. The retrievable blood clot filter according to claim 19, wherein the releasable lock includes an annular cover piece that covers at least a portion of the releasable upstream ends of all of the alignment ribs in a circumferential direction to prevent the release of the releasable upstream ends during a filtering operation of the filter.

24. The retrievable blood clot filter according to claim 23, wherein the annular cover piece includes biodegradable material which biodegrades over time.

25. The retrievable blood clot filter according to claim 19, wherein the releasable upstream end of the alignment ribs includes biodegradable material which biodegrades over time.

26. The retrievable blood clot filter according to claim 19, wherein the releasable upstream end of the alignment ribs includes a structurally weakened portion to reduce the force required to release the releasable upstream end from the releasable lock.

27. The retrievable blood clot filter according to claim 19, wherein the releasable upstream end of the alignment ribs is coupled to the releasable lock by an interference friction fit.

28. The retrievable blood clot filter according to claim 27, wherein the releasable lock is capable of releasing the at least one releasable upstream end of the alignment ribs in response to a longitudinal force applied to the at least one releasable upstream end.

29. The retrievable blood clot filter according to claim 19, wherein: the shaft is slidably coupled to the filter hub; andthe shaft includes a stop member adapted to prevent the filter section from separating from the alignment section when the at least one releasable upstream end of the alignment ribs is released from the releasable lock.

30. The retrievable blood clot filter according to claim 19, wherein the filter section further comprises a plurality of second filter legs each including first and second branch legs that extend radially outwardly from a branch point upstream of the filter hub.

31. A retrievable blood clot filter having a longitudinal axis comprising: a filter section having a plurality of filter legs;an alignment section having a plurality of alignment ribs and being spaced from the filter section along the longitudinal axis; anda releasable coupler positioned between the filter section and the alignment section, the releasable coupler releasably holding the upstream ends of the alignment ribs.

32. The retrievable blood clot filter according to claim 31, wherein the upstream ends of the alignment ribs are engaged to the releasable coupler to release in response to a force on the upstream ends of the alignment ribs.

33. The retrievable blood clot filter according to claim 32, wherein the upstream ends of the alignment ribs are engaged to the releasable coupler to release in response to a radially outward force on the upstream ends of the alignment ribs.

34. The retrievable blood clot filter according to claim 31, further comprising an axial engaging shaft extending through the coupler and adapted to retrieve the releasable coupler with the filter legs after the releasable upstream ends of the alignment ribs are released from the releasable coupler.

35. A retrievable blood clot filter comprising: a filter section having a plurality of filter legs;locking means; andan alignment section coupled to the filter section, the alignment section having a plurality of alignment ribs having releasable upstream ends coupled to the locking means, locking means capable of releasing at least one releasable upstream end of the alignment ribs.

36. The retrievable blood clot filter according to claim 35, wherein the locking means includes a plurality of recesses each receiving a corresponding releasable upstream end of the alignment ribs, wherein: each releasable upstream end includes at least one projecting surface; andeach recess includes at least one retaining surface facing the at least one projecting surface and retains the each releasable upstream end of the alignment ribs.

37. The retrievable blood clot filter according to claim 36, wherein the locking means includes a cover piece that covers at least a portion of the releasable upstream ends of all of the alignment ribs in a circumferential direction to prevent the release of the releasable upstream ends during a filtering operation of the filter.

38. The retrievable blood clot filter according to claim 37, wherein the cover piece includes biodegradable material which biodegrades over time.

39. The retrievable blood clot filter according to claim 35, wherein the releasable upstream end of the alignment ribs includes biodegradable material which biodegrade over time.

40. The retrievable blood clot filter according to claim 35, wherein the releasable upstream end of the alignment ribs includes a structurally weakened portion to reduce the force required to release the releasable upstream end from the locking means.

41. The retrievable blood clot filter according to claim 35, wherein the releasable upstream end of the alignment ribs is coupled to the locking means by an interference friction fit.

42. A blood clot filter comprising: a conical filter section having a filter hub and a plurality of filter legs having downstream ends coupled to the hub and upstream ends that extend radially outwardly; andan alignment section spaced from the filter section along a longitudinal axis in a non-overlapping manner, the alignment section having an alignment hub and a plurality of alignment ribs having downstream and upstream ends, the alignment ribs extending radially outwardly from the downstream ends and then further extending radially inwardly.

43. The blood clot filter according to claim 42, wherein when the blood clot filter is in a deployed state, each alignment rib covers a circumferential segment without overlap with the other alignment ribs.

44. The blood clot filter according to claim 42, wherein when the blood clot filter is in a deployed state, the alignment ribs are in circumferential alignment with the filter legs.

45. The blood clot filter according to claim 42, wherein the alignment section and the conical filter section are made from a single tubular element.

46. The blood clot filter according to claim 42, wherein the upstream end of each filter leg includes a wall engaging barb generally pointed in the downstream direction.

47. A method of retrieving a blood clot filter having a filter section and an alignment section, the alignment section including a plurality of alignment ribs with each alignment rib having a releasable upstream end, the method comprising: capturing the alignment section with a retrieval device;releasing the releasable upstream ends of the alignment ribs; andwithdrawing the filter into a retrieval sheath for removal.

48. The method according to claim 47, wherein the step of releasing includes applying a radially outward force on the releasable upstream ends so as to release the upstream ends from a releasable lock coupled to the filter section.

49. The method according to claim 47, wherein: the releasable upstream ends are friction fit with a releasable lock; andthe step of releasing includes applying a longitudinal force on the releasable upstream ends so as to overcome the retaining force of the friction fit.

50. The method according to claim 47, wherein: the releasable upstream ends of the alignment ribs include biodegradable material; andthe step of releasing includes letting the releasable upstream ends biodegrade over time to release the releasable upstream ends from the filter section.

51. The method according to claim 47, wherein: the releasable upstream ends of the alignment ribs include biodegradable material; andthe step of releasing includes letting the releasable upstream ends biodegrade over time to weaken the coupling of the releasable upstream ends to the filter section.

52. The method according to claim 47, wherein the step of capturing is performed after the step of releasing.

53. The method according to claim 47, wherein: the releasable upstream end of the alignment ribs includes a structurally weakened portion; andthe step of releasing includes applying a force on the weakened portion so as to release the upstream ends.