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 method of protecting a patient from embolization during a percutaneous procedure at a treatment site within a vessel comprising:
introducing a first elongate member into the vessel at a vessel access location, the first elongate member having an expandable filter carried on a distal portion thereof;
introducing a second elongate member into the vessel at the vessel access location, the second elongate member having an expandable treatment device carried on a distal portion thereof;
advancing the first elongate member through the vessel to position the expandable filter downstream of the treatment site;
advancing the second elongate member through the vessel to position the expandable treatment device within the treatment site;
expanding the expandable filter within the vessel;
expanding the treatment device radially outwardly at the treatment site, embolic particles released from the treatment site being prevented from flowing distally through the vessel by the expanded filter;
removing the second elongate member from the vessel;
after the second elongate member has been removed from the vessel, introducing a distal end of an elongate retrieval member into the vessel, the elongate retrieval member having a lumen sized to receive the first elongate member;
advancing the elongate retrieval member through the vessel over the first elongate member to retrieve the expandable filter; and
removing the elongate retrieval member, first elongate member and expandable filter from the vessel.
2. The method of claim 1 wherein the first elongate member is introduced into the vessel separately from the second elongate member.
3. The method of claim 1 wherein the first elongate member is advanced through the vessel independently of the second elongate member.
4. The method of claim 1 wherein the second elongate member includes a lumen sized to slideably accommodate the first elongate member and wherein the second elongate member is advanced through the vessel to the treatment site over the first elongate member.
5. The method of claim 1 wherein at least a portion of the expandable filter is self-expandable.
6. The method of claim 1 wherein the treatment site is a stenosis and wherein the step of expanding the vessel comprises urging the stenosis radially outwardly to squeeze the stenosis against a wall of the vessel.
7. The method of claim 1 wherein the first elongate member is a guidewire.