Single-wire expandable cages for embolic filtering devices

Abstract

A single-wire expandable cage for an embolic filtering device includes a single cage wire coupled to an elongated member, such as a guide wire, and adapted to expand from an unexpanded position to an expanded position in a patient's body vessel. The wire includes a first end and a second end which are coupled to the guide wire. A filter element is attached to the single-wire cage. The single-wire cage may be rotatably mounted to the guide wire or may be slidably disposed on the guide wire to allow the composite cage and filter element to be slid over the guide wire in an over-the-wire fashion once the guide wire is delivered to the target location in the patient's vasculature. One embodiment of the single-wire cage utilizes an offset arrangement in which the guide wire remains extended along the wall of the body vessel once the single-wire cage is deployed. Another embodiment of the device centers the guide wire within the body vessel.

What is claimed is:  
     
         1 . An embolic filtering device used to capture embolic debris in a body vessel, comprising: 
 a filter assembly including an expandable cage adapted to move between an unexpanded position and an expanded position and a filter element attached to the expandable cage, the cage forming an structure capable of opening the filter element and maintaining the filter element open until the cage is placed in the unexpanded position; and    an elongated member having a distal end and a proximal end, the expandable cage being coupled to the guide wire near the distal end, wherein the cage is made from a continuous wire having a first end coupled to the guide wire and a second end coupled to the guide wire, the first end and second end being spaced apart along the longitudinal axis of the guide wire.    
     
     
         2 . The filtering device of  claim 1 , wherein the cage forms a spiral shape when placed in the expanded position.  
     
     
         3 . The filtering device of  claim 1 , wherein the elongated member is a steerable guide wire.  
     
     
         4 . The filtering device of  claim 1 , wherein the wire is made from a material which is self expanding.  
     
     
         5 . The filtering device of  claim 1 , wherein the first end and second end of the expandable cage are rotatably mounted to the elongated member.  
     
     
         6 . The filtering device of  claim 1 , further including a pair of stop fittings mounted onto the elongated member, the first end of the expandable cage being mounted between the pair of stop fittings.  
     
     
         7 . The filtering device of  claim 6 , wherein the pair of stop fittings are positioned on the guide wire to allow the first end of the expandable cage to move longitudinally between the pair of stop fittings.  
     
     
         8 . The filtering device of  claim 1 , wherein the elongated member is centered in the body vessel when the expandable cage is deployed into the expanded position.  
     
     
         9 . The filtering device of  claim 1 , wherein the elongated member is deployed near the wall of the body vessel when the expandable cage is deployed.  
     
     
         10 . The filtering device of  claim 1 , wherein the wire forming the expandable basket is a wire ribbon.  
     
     
         11 . The filtering device of  claim 10 , wherein the wire ribbon is made from a nickel-titanium alloy.  
     
     
         12 . The filtering device of  claim 11 , wherein the expandable cage forms a spiral when placed in the expanded position.  
     
     
         13 . The filtering device of  claim 1 , wherein the expandable cage is slidably mounted to the elongated member to allow the filtering assembly to be moved along the length of the elongated member.  
     
     
         14 . The filtering device of  claim 1 , further including an obturator attached to the filtering element.  
     
     
         15 . The filtering device of  claim 1 , wherein the second elongated member is a tubular member.  
     
     
         16 . The filtering device of  claim 1 , wherein the expandable cage is movable between its expanded and unexpanded positions through relative longitudinal movement between the first elongated member and second elongated member.  
     
     
         17 . The filtering device of  claim 1 , wherein the cage forms a spiral shape when placed in the expanded position.  
     
     
         18 . The filtering device of  claim 1 , wherein the elongated member is a steerable guide wire.  
     
     
         19 . The filtering device of  claim 1 , wherein the wire is made from a material which is self expanding.  
     
     
         20 . The filtering device of  claim 1 , wherein the second elongated member is a tubular member.  
     
     
         21 . The filtering device of  claim 6 , wherein the expandable cage is movable between its expanded and unexpanded positions through relative longitudinal movement between the first elongated member and second elongated member.  
     
     
         22 . The filtering device of  claim 1 , further including a pair of stop fittings mounted onto the elongated member, the second end of the expandable cage being mounted between the pair of stop fittings.