Everting blood filter device

摘要

Everting filter devices and methods for using the devices, including using the devices as intra-vascular filters to filter thrombus, emboli, and plaque fragments from blood vessels. The filter devices include a filter body nominally tubular in shape and having a large proximal opening. The filter body can extend from a proximal first end region distally over the non-everted exterior surface of the filter, further extending distally to a distal-most region, then converging inwardly and extending proximally toward the filter second end region, forming a distal everted cavity. The degree of eversion of the filter can be controlled by varying the distance between the filler first end region near the proximal opening and the closed second end region. Bringing the filter first and second end regions closer together can bring filter material previously on the non-everted filter exterior to occupy the distal-most region. The everting process can also bring filter material previously in the distal-most position further into the distal everted cavity. The filter devices can be used to remove filtrate from body vessels, with the filtrate eventually occluding the distal-most region. The filter can then be further everted, bringing fresh, unoccluded filter material into place to provide additional filter capacity. Some everting filters have the capability of switching between occluding and filtering modes of operation, thereby allowing a treating physician to postpone the decision to use filtering or occluding devices until well after insertion of the device into the patient's body.