Embolic filter with a distal loop

Abstract

The invention provides a device for filtering emboli from blood flowing through a lumen defined by the walls of a vessel in a patient's body, comprising a filter element and a self-expanding radial element associated with the filter element. The filter element is expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained. The filter element comprises a self-expanding material having pores. The filter element has proximal and distal portions and a central portion, and has a shape in the expanded configuration which defines a cavity having a proximal facing opening. The self-expanding radial element is distal of the filter element, and the self-expanding radial element is adapted to maintain the filter element centered in the lumen.

1 - 20 . (canceled) 
     
     
         21 . A device for filtering emboli from blood flowing through a body lumen of a patient, the device comprising:
 an elongate support member;   a filter element attached to the elongate support member, the filter element being expandable from a collapsed configuration when the filter element is restrained to an expanded configuration when the filter element is unrestrained, wherein when the filter element is in the expanded configuration, the filter element defines a cavity having a proximal facing opening, and wherein the filter element comprises a self-expanding filter mesh material; and   a self-expanding radial element associated with the filter element, wherein the self-expanding radial element is distal of the filter element, and is configured to maintain the filter element centered in the body lumen.   
     
     
         22 . The device of  claim 21 , wherein the self-expanding radial element comprises a loop, and wherein the loop is generally circular in shape. 
     
     
         23 . The device of  claim 22 , wherein the self-expanding radial element has only one loop. 
     
     
         24 . The device of  claim 22 , wherein the self-expanding radial element comprises two or more loops. 
     
     
         25 . The device of  claim 21 , wherein the filter element has proximal and distal portions and a central portion, the filter element being attached to the elongate support member at the distal portion of the filter element. 
     
     
         26 . The device of  claim 21 , wherein the filter element has proximal and distal portions and a central portion, the filter element being attached to the elongate support member at the proximal portion of the filter element. 
     
     
         27 . The device of  claim 26 , wherein the filter element has proximal and distal portions and a central portion, the elongate support member being attached to the filter element at the proximal portion of the filter element by a single flexible tether. 
     
     
         28 . The device of  claim 21 , wherein the filter element is attached to the elongate support member by a sliding element. 
     
     
         29 . The device of  claim 21 , wherein the filter element is attached to the elongate support member by a fixed element. 
     
     
         30 . The device of  claim 21 , wherein the self-expanding radial element is adapted to not significantly impede the flow of blood through the lumen. 
     
     
         31 . The device of  claim 21 , wherein the device does not comprise any other self-expanding elements other than the self-expanding filter mesh material and the self-expanding radial element. 
     
     
         32 . The device of  claim 21 , wherein the self-expanding radial element is made of a nickel titanium wire. 
     
     
         33 . The device of  claim 21 , wherein when the self-expanding radial element is in its expanded configuration, the self-expanding radial element generally defines a plane substantially perpendicular to the elongate support member. 
     
     
         34 . The device of  claim 21 , wherein self-expanding filter mesh material defines pores, and when the filter element is in the expanded configuration, an average pore size is from 30 to 300 microns and the standard deviation of the pore size is less than 20 percent of the average pore size. 
     
     
         35 . The device of  claim 21 , wherein when the filter element is in the expanded configuration, the filter element has a percent open area greater than 50 percent. 
     
     
         36 . The device of  claim 21 , wherein the self-expanding filter mesh material has a tensile strength greater than 70,000 psi. 
     
     
         37 . The device of  claim 21 , wherein the self-expanding filter mesh material is made of metal. 
     
     
         38 . The device of  claim 21 , wherein the self-expanding element attached to the elongate support member. 
     
     
         38 . A device comprising:
 an elongate support member;   a filter element attached to the elongate support member, the filter element being expandable from a collapsed configuration to an expanded configuration, wherein when the filter element is in the expanded configuration, the filter element defines a cavity having a proximal facing opening, and wherein the filter element comprises a self-expanding filter mesh material; and   a self-expanding radial element attached to the elongate support member and configured to collapse into a catheter, wherein the self-expanding radial element is distal of the filter element, and is configured to maintain the filter element centered in a body lumen of a patient.   
     
     
         39 . The device of  claim 38 , further comprising a sliding element that slidably attaches the filter element to the elongate member, wherein the self-expanding radial element is attached to the elongate support member via the sliding element. 
     
     
         40 . The device of  claim 38 , wherein the self-expanding element comprises a hinge. 
     
     
         41 . The device of  claim 38 , wherein the self-expanding element comprises a zone of preferential bending. 
     
     
         42 . A method comprising:
 introducing a catheter in which a device is at least partially positioned into a body lumen of a patient, the device comprising:
 an elongate support member; 
 a filter element attached to the elongate support member, the filter element being expandable from a collapsed configuration when restrained within the catheter to an expanded configuration when unrestrained, wherein when the filter element is in the expanded configuration, the filter element defines a cavity having a proximal facing opening, and wherein the filter element comprises a self-expanding filter mesh material; and 
 a self-expanding radial element associated with the filter element, wherein the self-expanding radial element is distal of the filter element; 
   positioning the filter element distal to a treatment site;   deploying the filter element from the catheter and into the body lumen of the patient by at least withdrawing the catheter proximally, wherein after deploying the filter element from the catheter, the self-expanding element engages with a wall of the body lumen to maintain the filter element centered in the lumen defined by the vessel.   
     
     
         43 . The method of  claim 42 , wherein the device further comprises a sliding element that slidably attaches the filter element and the self-expanding radial element to the elongate support member, and a stop attached to the elongated member proximal to the sliding element, wherein as the catheter is withdrawn proximally, the filter element remains inside the catheter until the distal sliding element contacts the stop. 
     
     
         44 . The method of clam  42 , further comprising inserting a proximal end of the elongate member into a distal end of the catheter.