Guidewire with collapsible filter system and method of use

20080275485

11/396732

April 03, 2006

A guidewire with collapsible filter system and method of use where a deployable, collapsible and retrievable filter attached to a guidewire tube is utilized for filtering thrombotic particulate from blood flow in the vascular system during thrombectomy or other interventional vascular procedures.

Bonnette, Michael J. (Minneapolis, MN, US); Thor, Eric J. (Arden Hills, MN, US); Prather, Richard R. (St. Michael, MN, US); Farago, Laszlo Trent (Hudson, WI, US)

1. A guidewire with collapsible filter comprises: a. a guidewire having a distal portion which is tubular, the tubular portion having an interior and exterior aspect and a slot which communicates between the interior and exterior aspects; b. a flexible fine mesh collapsible filter of nitinol or other suitable material secured over and about the distal portion of the guidewire, the collapsible filter having a proximal end and a distal end, the distal end of the collapsible filter being attached to the distal portion of the guidewire; c. of the collapsible filter exhibits shape memory, so that when unrestrained the shape of the collapsible filter tends to return to a memory shape determined during fabrication, whereby such a shape is compressibly suitable for automatic deployed expansion from within a delivery sheath within and into a blood vessel or like vascular region for filtration of particulate caused by thrombectomy or other procedures; d. a flexible cord attached to the proximal end of the collapsible filter, the flexible cord passing through at least a portion of the interior aspect of the tubular distal portion of the guidewire and through the slot; and, e. the guidewire, the collapsible filter, and the flexible cord being configured so that tension applied to the flexible cord causes the collapsible filter to be drawn towards a collapsed configuration.

2. The guidewire with collapsible filter of claim 1, further comprising a delivery sheath which restrains the collapsible filter in a collapsed configuration for introduction and advancement.

3. The guidewire with collapsible filter of claim 1, wherein the memory shape is an expanded configuration so that when unrestrained the collapsible filter tends to expand and apply conforming and sealing forces on a vessel or passage wherein it is located.

4. The guidewire with collapsible filter of claim 3, wherein the collapsible filter is configured to allow passage of blood and smaller particles while filtering and capturing larger particles.

5. The guidewire with collapsible filter of claim 1, wherein the slot is elongated.

6. The guidewire with collapsible filter of claim 5, wherein in the collapsed introduction configuration the cord extends from the proximal end of the collapsible filter distally and into a distal portion of the slot.

7. The guidewire with collapsible filter of claim 1, further comprising frangible material located in the slot.

8. The guidewire with collapsible filter of claim 1, further comprising a retrieval catheter into which the collapsible filter is drawn.

9. The guidewire with collapsible filter of claim 1, further comprising a catheter for removal of filtered particles.

10. A method of filtering fluid in a vessel during treatment, comprising the steps of: a. providing a guidewire with a self-expanding collapsible filter having a tubular distal guidewire portion having a slot and a cord attached to the collapsible filter and passing through a portion of the tubular distal guidewire portion and through the slot; b. providing a delivery sheath; c. advancing the guidewire with collapsible filter to a desired location near a treatment location in a vessel, utilizing the delivery sheath to restrain the collapsible filter in a collapsed configuration; d. withdrawing the delivery sheath at least enough to uncover the collapsible filter and allowing the collapsible filter to expand; e. performing a treatment in the body vessel while the expanded collapsible filter provides filtering of particulate in the vessel; d. applying tensile force to the cord thereby collapsing the collapsible filter; and, f. removing the collapsible filter from the vessel.

11. The method of claim 10, further comprising the steps of: a. providing a retrieval sheath; b. withdrawing the collapsed collapsible filter into the retrieval sheath; and, c. removing the collapsible filter and the retrieval sheath from the vessel.

12. The method of claim 10, further comprising the steps of: a. providing a thrombectomy catheter; and, b. using the thrombectomy catheter to remove filtered material from the collapsible filter prior to removing the collapsible filter from the vessel.

13. The method of claim 10, wherein the treatment includes a treatment selected from the list consisting of angioplasty, stenting, atherectomy, embolectomy, thrombectomy, and medication delivery.

14. The method of claim 10, further comprising the steps of: a. providing frangible material in the slot; and, b. displacing at least some of the frangible material during the application of tensile force to the cord.

606/200

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edspap.20080275485