Patent ID: 7922732

Claim:
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.