Vena cava filter

• US 6,436,120 B1
• Filed: 06/27/2000
• Issued: 08/20/2002
• Est. Priority Date: 04/20/1999
• Status: Expired due to Term

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: Allen J. Meglin
• Inventors: Meglin, Allen J.
• Primary Examiner(s): TRUONG, KEVIN THAO
• Application Number:
  US09/604,384
• Time in Patent Office: 784 Days
• Field of Search: 606/200, 606/169, 606/198, 606/191, 606/199, 606/197, 606/127, 606/114, 606/1
• US Class Current: 606/200
• CPC Class Codes: A61F 2/0103 With centering means
• CPC Class Codes: A61F 2/0105 Open ended, i.e. legs gathered only at one side
• CPC Class Codes: A61F 2/0108 Both ends closed, i.e. legs gathered at both ends
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0058 X-shaped
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/0069 cylindrical
• CPC Class Codes: A61F 2230/0076 ellipsoidal or ovoid
• CPC Class Codes: A61F 2250/0098 radio-opaque, e.g. radio-opaque markers

Abstract

A vena cava filter and placement set includes features which can be visualized utilizing sonography. A method of implanting a vena cava filter employs sonography to enable the surgeon to direct the filter to a desired location and ensure that the filter is properly deployed. Designs include members of wire and slotted tubes, constructed of temperature-sensitive shape memory materials and of mechanically expanded materials.

Claims

1. A filter, implantable in a blood vessel by sonographic visualization, comprising:

one or more members arranged to trap blood clots without substantially interfering with normal blood flow; and

a sonographically conspicuous feature on at least one member, so the filter position can be determined by sonographic visualization.

2. The filter of claim 1, wherein the sonographically conspicuous feature is an echogenic feature.

3. The filter of claim 2, wherein the echogenic feature comprises:

a textured surface.

4. The filter of claim 3, wherein the textured surface comprises:

an etched region.

5. The filter of claim 2, wherein the echogenic feature comprises:

at least one of a sharp corner and a sharp edge.

6. The filter of claim 2, wherein the echogenic feature comprises:

an echogenic coating.

7. The filter of claim 2, wherein a marker wire is employed to assist in placement, the marker wire further comprising:

a plurality of echogenic markers on the marker wire, whereby correct visualization in a sonogram of a true longitudinal slice along the filter axis is readily ascertainable by presence in the sonogram of each of the plurality of echogenic markers.

8. The filter of claim 7, wherein the filter further comprises:

a tube through which the marker wire is threaded, correct visualization additionally confirmed by presence in the sonogram of the tube in its entirety.

9. The filter of claim 2, wherein correct visualization in a sonogram of a true longitudinal slice along the filter axis is readily ascertainable by presence in the sonogram of the echogenic feature.

10. The filter of claim 9, wherein the filter further comprises:

an additional echogenic feature, correct visualization additionally confirmed by presence in the sonogram of both the echogenic feature and the additional echogenic feature.

11. The filter of claim 2, wherein the one or more members are arranged to define a cone-shaped basket attached to the echogenic feature at a vertex.

12. The filter of claim 11, wherein the members are further arranged to define a substantially coplanar flower, the echogenic feature attached thereto at a center thereof.

13. The filter of claim 12, further comprising an outer ring connecting a base of the cone to an outer position of the flower.

14. The filter of claim 11, further comprising:

a plurality of echogenic markers substantially at a periphery of a base of the cone.

15. The filter of claim 11, further comprising:

a plurality of loops at a periphery of the basket, whereby the basket is axially aligned thereby during deployment thereof.

16. The filter of claim 11, wherein the basket is defined by substantially radially extending members.

17. The filter of claim 11, wherein the basket is defined by a mesh of members extending in both radial directions and directions transverse the radial directions.

18. The filter of claim 2, further comprising:

a plurality of echogenic markers substantially at a periphery of the filter, whereby deployment thereof can be visualized.

19. The filter of claim 2, further comprising:

an expanded, slotted tube having slots along a predetermined length thereof, the slots dividing the slotted tube into the one or more members.

20. The filter of claim 2 wherein the one or more members are composed of a material having a temperature-sensitive shape memory.

21. The filter of claim 20 wherein the filter has a deployed shape at human body temperature and a compact shape for implantation at a temperature other than human body temperature.

22. The filter of claim 1, wherein the sonographically conspicuous feature is a sonically absorptive feature.

23. The filter of claim 22, wherein the sonically absorptive feature is a coating.

24. A caval filter placement set, comprising:

a guide wire;

a dilator;

a sheath for introducing the filter; and

a caval filter including one or more members arranged to trap blood clots without substantially interfering with normal blood flow; and

a sonographically conspicuous feature on the caval filter, so the filter position can be determined by sonographic visualization.

25. The set of claim 24, wherein the sonographically conspicuous feature is an echogenic feature.

26. The set of claim 25, the sheath further comprising an echogenic feature at a distal end thereof.

27. The set of claim 25, the dilator further comprising an echogenic feature at a distal end thereof.

28. The set of claim 25, the guide wire further comprising plural echogenic features.

29. The set of claim 28, wherein the guide wire has a hooked end, which can engage a renal vein when positioned in the cava.

30. The filter of claim 24, wherein the sonographically conspicuous feature is a sonically absorptive feature.

31. The filter of claim 30, wherein the sonically absorptive feature is a coating.