Patent ID: 6258026
Filing Date: 2001-07-10
Classification: A61F

Abstract:
A removable blood clot filter having leading and trailing ends and a filter central longitudinal axis and which is collapsible in a collapsed configuration toward said filter longitudinal axis for insertion into a blood vessel and is radially expandable outwardly from said filter longitudinal axis to an expanded configuration to contact and penetrate an inner wall of said blood vessel to provide a filter migration resistance force sufficient to prevent filter migration in response to blood pressure within said blood vessel comprising:a plurality of elongate, spaced appendages having first and second ends, the first ends of said plurality of elongate spaced appendages being formed to extend outwardly toward said filter leading end away from said filter longitudinal axis in the expanded configuration of said filter, each of a plurality of said elongate spaced appendages having an appendage longitudinal axis and a pointed hook formed at the second end thereof which extends laterally outward relative to said appendage longitudinal axis in a direction away from said filter longitudinal axis to engage and penetrate the vessel inner wall in the expanded configuration of said filter, each said hook being formed with a maximum migration force such that a force above said maximum migration force applied to said hook as a result of a withdrawal force in excess of said filter migration resistance force applied to the trailing end of said filter in a direction away from the filter leading end will cause said hook to straighten and bend toward the filter longitudinal axis and toward a configuration parallel with the appendage longitudinal axis, to facilitate removal of the hook from the vessel wall without tearing the vessel wall, the sum of the maximum migration forces for the hooks for said filter being substantially equal to the filter migration resistance force.