Percutaneous Retrievable Vascular Filter

• US 20110137335A1
• Filed: 03/11/2010
• Published: 06/09/2011
• Est. Priority Date: 09/07/2007
• Status: Active Grant

• Current Assignee: Merit Medical Systems, Inc.
• Original Assignee: Crusader Medical, LLC
• Inventors: Hallisey, Michael J.
• Granted Patent: US 8,795,318 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61F 2/011 Instruments for their placement or removal
• CPC Class Codes: A61F 2/012 Multiple filtering units
• CPC Class Codes: A61F 2002/016 made from wire-like elements
• CPC Class Codes: A61F 2002/061 provided with means for allowing access to secondary lumens
• CPC Class Codes: A61F 2230/005 Rosette-shaped, e.g. star-shaped
• CPC Class Codes: A61F 2230/0076 ellipsoidal or ovoid
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: A61F 2230/0093 Umbrella-shaped, e.g. mushroom-shaped
• CPC Class Codes: A61F 2250/0059 temporary

Abstract

Retrievable vena cava filters for the temporary or permanent prevention of Pulmonary embolism (PE) are disclosed. A filter in accordance with the present invention has a tube-within-tube structure with overlapping semi-spheres. The semi-spheres comprise a plurality of expandable legs. The first tube may have a plurality of slots allowing for deployment of a first or second sets of expandable legs on the second tube. The free end of each leg in the first set of expandable legs may be oriented in a direction the same as or opposite to the free end of each leg in the second set. The filter may also be formed from a single tube. In certain embodiments, the filter of the present invention can be retrieved from either end.

Claims

1. A filter comprising,

a first tube having a plurality of a first set of slots, a plurality of a second set of slots, a plurality of a first set of expandable legs, each leg of the first set having an end secured to the first tube and a free end,

a second tube having a plurality of a second set of expandable legs and a plurality of a third set of expandable legs, each leg of the second set having an end secured to the second tube and a free end,

each leg of the third set comprising an expandable segment and having both ends secured to the second tube,

each slot of the first set of slots being positioned at a radial position on the first tube allowing for deployment of each expandable leg of the second set, each slot of the second set of slots being positioned at a radial position on the first tube allowing for deployment of the expandable segment in each leg of the third set, the slots being oriented parallel to the cylindrical axis of the first tube,

the second tube'"'"'s external diameter being less than the first tube'"'"'s internal diameter,

wherein the second tube is inserted into the first tube such that the free end of each leg in the first set is oriented in a direction opposite to the free end of each leg in the second set.

2. The filter of claim 1 wherein the filter is encased in a catheter in an undeployed state.

3. The filter of claim 1 wherein each expandable leg of the first and second sets are deployed.

4. The filter of claim 3 wherein a cage is formed comprising expandable legs from the first and second sets.

5. The filter of claim 1 wherein each expandable leg of the first set has at least one barb on the free end.

6. The filter of claim 1 wherein at least one end of the first tube and/or the second tube has at least one notch.

7. The filter of claim 1 wherein each of the expandable legs of the first and second sets comprises memory metal.

8. The filter of claim 1 wherein the expandable segment of the expandable legs of third set comprises memory metal.

9. The filter of claim 1 wherein the number of expandable legs in the first set ranges from about 2 to about 20.

10. The filter of claim 9 wherein the number of expandable legs ranges from about 4 to about 15.

11. The filter of claim 10 wherein the number of expandable legs ranges from about 4 to about 10.

12. The filter of claim 1 wherein the number of expandable legs in the first set is four, A, B, C and D, the number of legs in the second set is four, E, F, G and H, and the number of legs in the third set is four, I, J, K and L.

13. The filter of claim 12 wherein the expandable legs in the first set are secured at radial positions along the first tube'"'"'s circumference ranging from about 0°

to about 90°

for A, about 90°

to about 180°

for B, about 180°

to about 270°

for C, and about 270°

to about 360°

for D.

14. The filter of claim 12 where the radial positions of the first set of expandable legs, A, B, C and D are symmetrical.

15. The filter of claim 12 wherein the expandable legs in the second set are secured at radial positions along the second tube'"'"'s circumference ranging from about 0°

to about 90°

for E, about 90°

to about 180°

for F, about 180°

to about 270°

for G, and about 270°

to about 360°

for H.

16. The filter of claim 12 where the radial positions of the second set of expandable legs, E, F, G and H are symmetrical.

17. The filter of claim 4 wherein the cage forms a sphere shape when the expandable legs of the first and second set are deployed, where the expandable segment of each expandable leg in the third set forms a curvilinear shape when deployed and where the barb on the end of free end is inserted into a vessel wall.

36. A method for retrieving the filter of claim 6 comprising the steps of,

inserting a catheter into a vessel where the filter is positioned on the vessel wall,

pushing a snare through the catheter until the snare grabs the notch,

pulling back on the snare to exert tension on the filter,

pushing the catheter over the snare and each expandable leg of the third set until each expandable leg of the third set straightens, each expandable leg of the first set retracts from the vessel wall, and each expandable leg of the second set retracts from vessel wall,

encompassing the expandable legs of the first, second and third sets in the catheter and,

withdrawing the filter.

18. A filter comprising,

a tube having a plurality of a first set of expandable legs and a plurality of a second set of expandable legs, each leg of the first set and the second set having an end secured to the tube and a free end, the free end of each leg in the first set being oriented in a direction opposite to the free end of each leg in the second set.

19. The filter of claim 18, wherein at least one end of the filter has at least one notch.

20. The filter of claim 18, wherein the filter is encased in a catheter in an undeployed state.

21. The filter of claim 18, wherein each expandable leg of the first and second sets are deployed.

22. The filter of claim 18, wherein a cage is formed comprising expandable legs from the first and second sets.

23. The filter of claim 18, wherein each expandable leg of the first set has at least one barb on the free end.

24. The filter of claim 18, wherein the number of expandable legs in the first set is five, and the number of legs in the second set is five.

25. The filter of claim 18, wherein each leg of the first and the second sets is bent inward at the end closest to the tube.

37. A method for retrieving the filter of claim 19 comprising the steps of,

inserting a catheter into a vessel where the filter is positioned on the vessel wall,

pushing a snare through the catheter until the snare grabs the notch on the tube closest to the first set of expandable legs,

pulling back on the snare to exert tension on the filter,

pushing the catheter over each expandable leg of the first set until each expandable leg retracts from the vessel wall,

continuing pushing the catheter over the second set of expandable legs until each expandable leg of the second set inverts and retracts from vessel wall,

encompassing the expandable legs of the first and second sets in the catheter and,

withdrawing the filter.

26. A filter comprising,

a first tube having a plurality of a first set of expandable legs and a plurality of a first set of slots, each leg of the first set having an end secured to the first tube and a free end,

a second tube having a plurality of a second set of expandable legs, each leg of the second set having an end secured to the second tube and a free end,

the free end of each leg in the first set being oriented in a direction opposite to the free end of each leg in the second set,

each slot of the first set on the first tube being positioned at a radial position allowing for deployment of each leg of the second set, the slots being oriented parallel to the cylindrical axis of the first tube,

wherein the second tube'"'"'s external diameter is less than the first tube'"'"'s internal diameter, and wherein the second tube is inserted into the first tube.

27. The filter of claim 26 wherein there is a cap at one end of the first tube.

28. The filter of claim 26 wherein at least one end of the first tube has at least one notch.

29. The filter of claim 26, wherein the filter is encased in a catheter in an undeployed state.

30. The filter of claim 26, wherein each expandable leg of the first and second sets are deployed.

31. The filter of claim 26, wherein a cage is formed comprising expandable legs from the first and second sets.

32. The filter of claim 26, wherein each expandable leg of the first set has at least one barb on the free end.

33. The filter of claim 26, wherein the number of expandable legs in the first set is five, and the number of legs in the second set is five.

38. A method for retrieving the filter of claim 28 comprising the steps of,

inserting a catheter into a vessel where the filter is positioned on the vessel wall,

pushing a snare through the catheter until the snare grabs the notch on the first tube,

pushing a wire through the catheter and the inner space of the first tube until the wire reaches the second tube or pin,

pulling back on the snare to exert tension on the filter,

pushing the catheter over each expandable leg of the first set until each expandable leg of the first set retracts from the vessel wall,

pushing the wire to push the second tube or pin away from the snare to exert tension on the second set of expandable legs until the second set of expendable legs retract from the vessel wall,

encompassing the expandable legs of the first and second sets in the catheter and,

withdrawing the filter.

34. A filter comprising,

a first tube having a plurality of a first set of slots and a plurality of a second set of slots,

a second tube having a plurality of a first set of expandable legs and a plurality of a second set of expandable legs, each leg of the first set and the second set having an end secured to the second tube and a free end, the free end of each leg in the first set being oriented in a direction opposite to the free end of each leg in the second set,

each slot of the first set of slots on the first tube being positioned at a radial position allowing for deployment of each expandable leg of the first set, each slot of the second set of slots on the first tube being positioned at a radial position allowing for deployment of each leg of the second set, the slots being oriented parallel to the cylindrical axis of the first tube,

wherein the second tube'"'"'s external diameter is less than the first tube'"'"'s internal diameter, and wherein the second tube is inserted into the first tube.

35. The filter of claim 34, wherein at least one end of the first tube has at least one notch.

39. A method for retrieving the filter of claim 35 comprising the steps of,

inserting a catheter into a vessel where the filter is positioned on the vessel wall,

pushing a snare through the catheter and the inner space of the second tube until the snare grabs the notch on the first tube proximal to the second set of expandable legs,

pulling back on the snare to exert tension on the filter,

pushing the catheter over each expandable leg of the first set until each expandable leg retracts from the vessel wall, meanwhile, pulling back on the snare and the first tube to exert tension on the second set of expandable legs until each expandable leg of the second set retracts from vessel wall,

encompassing the expandable legs of the first and second sets in the catheter and,

withdrawing the filter.