Floating carotid filter

Abstract

A system for treating tandem occlusions (e.g. a clot causing ischemic stroke downstream of a carotid lesion with plaque buildup) in the vasculature can have a carotid filter with a retrieval feature near the proximal end, a deployment system configured to engage the retrieval feature as the vascular filter is delivered intravascularly and disengage the retrieval feature when the filter is anchored in place, and an engagement system configured to engage the retrieval feature while the filter is anchored and retract the filter. The carotid filter can remain in place during the patient's recovery period following the ischemic stroke until a procedure to treat the remaining occlusion is completed.

1 . A system comprising:
 a vascular filter comprising porous distal portion, a porous proximal portion comprising a porosity larger than the porous distal portion, an expandable frame configured to anchor within vasculature, and a retrieval feature disposed approximate a proximal end of the vascular filter;   a deployment system configured to engage the retrieval feature as the vascular filter is delivered intravascularly and disengage the retrieval feature when the expandable frame is anchored within vasculature; and   an engagement system configured to engage the retrieval feature when the expandable frame is anchored within the vasculature and retract the vascular filter.   
     
     
         2 . The system of  claim 1 , the expandable frame comprising a plurality of struts extending longitudinally from approximate the proximal end of the vascular filter to approximate a distal end of the vascular filter and being configured to move from a collapsed configuration sized to traverse a catheter to an expanded configuration configured to extend radially upon exiting the catheter. 
     
     
         3 . The system of  claim 2 , the porosity of the porous proximal portion being defined by spacing between the plurality of struts when the expandable frame is in the expanded configuration,
 the vascular filter further comprising a mesh affixed to the expandable frame, and   the porosity of the distal portion being defined by the porosity of the mesh.   
     
     
         4 . The system of  claim 1 , the retrieval feature comprising a protrusion extending radially approximate the proximal end of the vascular filter. 
     
     
         5 . The system of  claim 4 , one or both of the deployment system and the engagement system comprising a looped wire configured to lasso around the protrusion of the retrieval feature. 
     
     
         6 . The system of  claim 4 , one or both of the deployment system and the engagement system comprising a catheter and two or more arms comprising indentations thereon,
 the two or more arms being movable between a collapsed configuration sized to at least partially reside within the catheter and an expanded configuration when moved from inside the catheter to outside the catheter,   the indentations being sized to collapse over the protrusion, thereby engaging the arms to the protrusion, when the arms are in the collapsed configuration, and   the arms being configured to disengage the protrusion when in the expanded configuration.   
     
     
         7 . The system of  claim 1 , the engagement system being further configured to at least partially collapse the vascular filter. 
     
     
         8 . The system of  claim 1 , the deployment system being pushable to move the vascular filter through a catheter. 
     
     
         9 . The system of  claim 1 , the engagement system being pullable to move at least a portion of the vascular filter into a catheter. 
     
     
         10 . The system of  claim 1 , the porosity of the distal portion being sized to capture a liberated thrombus when the expandable frame is anchored within vasculature, and
 the porosity of the proximal portion being sized to allow the liberated thrombus to pass therethrough.   
     
     
         11 . A system comprising:
 a thrombectomy device;   a stent;   a vascular filter comprising a porous portion, an expandable frame configured to anchor within vasculature, and a retrieval feature disposed approximate a proximal end of the vascular filter;   a deployment system configured to engage the retrieval feature as the vascular filter is delivered intravascularly and disengage the retrieval feature when the expandable frame is anchored within vasculature; and   an engagement system configured to engage the retrieval feature when the expandable frame is anchored within the vasculature and retract the vascular filter.   
     
     
         12 . The system of  claim 11 , the porous portion comprising a proximal section and a distal section, and
 the proximal section comprising a porosity larger than the distal section.   
     
     
         13 . The system of  claim 11 , the retrieval feature comprising a radially-enlarged bump approximate the proximal end of the vascular filter. 
     
     
         14 . The system of  claim 13 , one or both of the deployment system and the engagement system comprising a looped wire configured to lasso around the retrieval feature. 
     
     
         15 . The system of  claim 14 , the looped wire further configured to engage a notch when lassoed around the retrieval feature. 
     
     
         16 . The system of  claim 14 , the looped wire further configured to be tightened to a smaller loop opening by retracting the wire into a tube. 
     
     
         17 . The system of  claim 14 , the looped wire further configured to be loosened to a larger loop opening by advancing the wire from a tube. 
     
     
         18 . The system of  claim 13 , one or both of the deployment system and the engagement system comprising two or more arms comprising indentations thereon, the indentations sized to collapse over and engage the radially-enlarged bump. 
     
     
         19 . The system of  claim 11 , the deployment system and the engagement system being substantially similar systems. 
     
     
         20 . The system of  claim 11 , the vascular filter being configured to remain anchored in an artery during a patient stabilization time period during which a patient stabilizes following a thrombectomy.