Embolic filters having multiple layers and controlled pore size

• US 20070198051A1
• Filed: 04/26/2007
• Published: 08/23/2007
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: ev3, Inc. (Medtronic Plc)
• Inventors: Kusleika, Richard, Oslund, John, Clubb, Thomas
• Granted Patent: US 8,137,376 B2
• Time in Patent Office: Days
• US Class Current: 606/200
• CPC Class Codes: A61F 2002/015 Stop means therefor
• CPC Class Codes: A61F 2002/018 made from tubes or sheets of material, e.g. by etching or laser-cutting
• CPC Class Codes: A61F 2230/0006 circular
• CPC Class Codes: A61F 2230/0008 elliptical or oval
• CPC Class Codes: A61F 2230/0067 conical
• CPC Class Codes: A61F 2230/008 paraboloidal
• CPC Class Codes: D04C 1/02 made from particular materials
• CPC Class Codes: D10B 2509/06 Vascular grafts; stents

Abstract

The invention provides a device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body comprising a filter element. The filter element is expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained. When the filter element is in the expanded configuration, the average pore size is from 30 to 300 microns and the standard deviation of the pore size is less than 20 percent of the average pore size. The filter element has two or more filtering layers, each filtering layer having pores, each filtering layer being adjacent to at least one other filtering layer, and at least one of the filtering layers being made of a self-expanding material.

Claims

1. A device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient'"'"'s body, comprising:

a filter element being expandable from a collapsed configuration to an expanded configuration, wherein when the filter element is in the expanded configuration, the average pore size is from 30 to 300 microns and the standard deviation of the pore size is less than 20 percent of the average pore size, and wherein the filter element comprises two or more filtering layers, each filtering layer comprising pores, and each filtering layer being adjacent to at least one other filtering layer.

2. A device of claim 1, wherein when the filter element is in the expanded configuration, the average pore size is from 30 to 150 microns.

3. A device of claim 1, wherein when the filter element is in the expanded configuration, the average pore size is from 100 to 140 microns.

4. A device of claim 1, wherein when the filter element is in the expanded configuration, the average pore size is from 40 to 70 microns.

5. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 15 percent of the average pore size.

6. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 10 percent of the average pore size.

7. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 5 percent of the average pore size.

8. A device of claim 1, wherein when the filter element is in the expanded configuration, the standard deviation of the pore size is less than 2 percent of the average pore size.

9. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 50 percent.

10. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 60 percent.

11. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 70 percent.

12. A device of claim 1, wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 80 percent.

13. A device of claim 1, wherein at least one of the filtering layers has a tensile strength greater than 70,000 psi.

14. A device of claim 1, wherein at least one of the filtering layers has a tensile strength greater than 100,000 psi.

15. A device of claim 1, wherein at least one of the filtering layers has a tensile strength greater than 200,000 psi.

16. A device of claim 1, wherein at least one of the filtering layers is made of metal.

17. A device of claim 1, wherein at least one of the filtering layers is made of nitinol.

18. A device of claim 1, further comprising an elongate support member and wherein the filter element is carried on a portion of the elongate support member.

19. A device of claim 1, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening.

20. A device of claim 19, wherein at least one of the filtering layers comprises wires braided to form diamond-shaped pores.

21. A device of claim 1, wherein the filter element comprises a mesh rolled back on itself to form two filtering layers.

22. A device of claim 21, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening.

23. A device of claim 22, wherein the filter element comprises a drawstring tether at the proximal facing opening of the filter element.

24. A device of claim 22, wherein at least one of the filtering layers comprises wires braided to form diamond-shaped pores.

25. A device of claim 1, wherein the filter element comprises two separate filtering layers.

26. A device of claim 25, wherein the filter element has proximal and distal portions and a central portion, the filter element having a shape in the expanded configuration which defines a cavity having a proximal facing opening.

27. A device of claim 25, wherein at least one of the filtering layers comprises wires braided to form diamond-shaped pores.

28. A device of claim 25, wherein the two separate filtering layers have different average pore sizes.

29. A device of claim 25, wherein the two separate filtering layers are not attached to each other.

30. A device of claim 25, wherein the two separate filtering layers are attached to each other.

31. A device of claim 30, wherein the two separate filtering layers are attached to each other by a fixed element.

32. A device of claim 30, wherein the two separate filtering layers are attached to each other by a sliding element.

33. A device of claim 30, wherein the two separate filtering layers are attached to each other by a tether.

34. A device of claim 25, wherein a first filtering layer comprises wires braided to from diamond-shaped pores, and the second filtering layer comprises a coiled wire.