BLOOD CLOT FILTERING

摘要

A blood clot filter comprising: an anchoring portion (402) comprising a generally cylindrical self-expanding body formed from resilient material, the generally cylindrical body having proximal and distal ends and defining an axial direction and having a structure of variable size diameter expandable from a low-profile compressed condition to a larger profile expanded condition, wherein the resilient material urges the generally cylindrical body to radially expand and to thereby apply anchoring radial force against the inner wall surface of a blood vessel; and a generally conical filtering portion (400) axially aligned with the generally cylindrical body (402) having an open proximal end (406) coupled to the distal end of the anchoring portion (402) and having an apical distal end (404). In a preferred embodiment, the filter portion (400) is formed from strands (410) of resilient material that extend from the apical distal end (404) to the open proximal end (406). The strands (410) form twisted pairs (408) that converge at the apical distal end (404). The strands (410) diverge from the twisted pairs (408) in crossing paths to form a pattern of open filtering cells (A, B, C). Also disclosed is a blood clot filter having one or more hooks (413) fixedly coupled to the anchoring portion (402) and formed from compliant material having an original shape that bends under stress yet returns to its original shape when unstressed. The hooks respectively tend to project from the anchoring portion (402) at an acute angle with respect to the axial direction for engagement with a vessel wall. Also, the hooks (413) are deflectable toward the anchoring portion for achieving a low-profile.