Method and device for filtering body fluid
Medical devices for filtering fluids flowing through a lumen and a method of forming medical devices. The devices can be used in vascular channels, urinary tracts, biliary ducts and the like, and filter emboli and other debris generated at a treatment site.
1. A system for filtering material from fluid flowing through a lumen defined by the wall of an anatomical structure comprising:
a guidewire;
a filter element carried on the guidewire, the filter element having proximal and distal ends and being formed of a self-expanding porous fabric material, the fabric material being configured to be expandable within the lumen of the anatomical structure from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained without the aid of other mechanically expandable or self-expandable structure, the filter element having a shape in the expanded configuration which defines a cavity having a proximally facing opening, the guidewire extending to at least the distal end of the filter element; and
a retrieval catheter having a distal portion defining a lumen, the retrieval catheter being configured and sized such that during use of the system the lumen of the retrieval catheter accommodates the guidewire and at least the proximally facing opening of the filter without significant loss of material during retrieval of the filter from the lumen of the anatomical structure.
2. The system of claim 1 wherein the porous fabric material comprises a metal mesh.
3. The system of claim 1 wherein the filter element is attached to the guidewire at a distal region of the guidewire.
4. The system of claim 1 wherein the metal mesh comprises nitinol.
5. The system of claim 1 wherein the distal end of the filter element is connected to a distal band which encircles the guidewire.
6. The system of claim 5 wherein the proximal end of the filter element is connected to a proximal band which encircles the guidewire.
7. The system of claim 6 wherein one of the proximal and distal bands is connected in a fixed position on the guidewire.
8. The system of claim 6 wherein the proximal band is slidably disposed about the guidewire.
9. The system of claim 1 wherein the filter element is mounted on the guidewire.
10. A system for capturing thrombi removed from the wall of a vessel at a site in the lumen of the vessel comprising:
a guidewire;
an intravascular device carried on the guidewire, the intravascular device having pores and having proximal and distal ends and being formed of a self-expanding porous fabric material, the fabric material being configured to be expandable from a collapsed configuration when the intravascular device is restrained to an expanded configuration when the intravascular device is unrestrained without the aid of other mechanically expandable or self-expandable structure, the intravascular device having a shape in the expanded configuration which forms an interior portion having a proximally facing opening defined by a lip which is sized to expand to the size of the lumen of the vessel when the intravascular device is deployed in the vessel, the proximally facing opening being sized to allow the thrombi to enter the interior portion of the intravascular device, the pores being configured to retain the thrombi in the interior portion of the intravascular device; and
a retrieval catheter having a distal portion defining a lumen, the retrieval catheter being configured and sized such that during use of the system the lumen of the retrieval catheter accommodates the guidewire and at least the proximally facing opening of the intravascular device without significant loss of thrombi during retrieval of the intravascular device from the lumen of the vessel.
11. The system of claim 10 wherein the porous fabric material comprises a metal mesh.
12. The system of claim 11 wherein the metal mesh comprises nitinol.
13. The system of claim 10 wherein the intravascular device is attached to the guidewire at a distal region of the guidewire.
14. The system of claim 10 wherein the distal end of the intravascular device is connected to a distal band which encircles the guidewire.
15. The system of claim 14 wherein the proximal end of the intravascular device is connected to a proximal band which encircles the guidewire.
16. The system of claim 15 wherein one of the proximal and distal bands is connected in a fixed position on the guidewire.
17. The system of claim 15 wherein the proximal band is slidably disposed about the guidewire.
18. The system of claim 10 wherein the intravascular device is a filter.
19. The system of claim 18 wherein the filter comprises a metal mesh.
20. The system of claim 19 wherein the metal mesh comprises nitinol.
21. The system of claim 10 wherein the intravascular device is mounted on the guidewire.