Filter apparatus for ostium of left atrial appendage

Abstract

Apparatus for permanent placement across an ostium of a left atrial appendage in a patient, which includes a filtering membrane configured to extend across the ostium of the left atrial appendage. The filtering membrane has a permeable structure which allows blood to flow through but substantially inhibits thrombus from passing therethrough. The apparatus also includes a support structure attached to the filtering membrane which retains the filtering membrane in position across the ostium of the left atrial appendage by permanently engaging a portion of the interior wall of the left atrial appendage. The support structure may be radially expandable from a first configuration to a second configuration which engages the ostium or the interior wall of the left atrial appendage. The filtering membrane may define an opening therethrough that is configured to expand from a first size which inhibits the passage of thrombus therethrough to a second size which allows an interventional device, e.g., an expansion balloon, to pass therethrough, and wherein the opening is resiliently biased towards the first size.

What is claimed is: 
     
         1 . A method of preventing atrial appendage thrombi from entering a blood stream, the method comprising:
 introducing an apparatus having a proximal end and a distal end to an ostium of a left atrial appendage (LAA), the apparatus comprising:
 an attachment member having a first diameter; 
 wherein the attachment member includes a plurality of strut wires, the plurality of strut wires includes a first portion and a second portion; 
 wherein the first portion of the plurality of strut wires extends towards the proximal end and the second portion of the plurality of strut wires extends towards the distal end; 
 a filter portion having a second diameter disposed at the proximal end; 
 a support having a diameter substantially smaller than the first diameter and the second diameter, and configured for coupling the attachment member and the filter portion; 
   positioning the attachment member within a cavity defined by the LAA such that the attachment member engages a portion of an interior wall of the LAA; and   positioning the filter portion proximate the ostium of the LAA such that the proximal end engages a portion of an outer wall of the LAA and the filter portion extends across the ostium of the LAA.   
     
     
         2 . The method of  claim 1 , wherein the support is configured to be positioned within the ostium of the LAA. 
     
     
         3 . The method of  claim 1 , wherein the support is configured to maintain the plurality of strut wires in the proper configuration. 
     
     
         4 . The method of  claim 1 , wherein introducing the apparatus to the ostium of the LAA comprises advancing a catheter device partially within the LAA. 
     
     
         5 . The method of  claim 4 , wherein the catheter device includes an outer sheath and an inner member, the inner member slidably receivable within an interior of the outer sheath. 
     
     
         6 . The method of  claim 5 , wherein positioning the apparatus within the outer sheath and at least in part over the inner member deflects the plurality of strut wires from a first expanded configuration to a second compressed configuration. 
     
     
         7 . The method of  claim 5 , wherein longitudinal movement of the outer sheath relative to the inner member allows for deployment of the apparatus within the LAA. 
     
     
         8 . The method of  claim 1 , wherein the filter portion includes a filtering membrane configured to allow blood to pass therethrough and inhibit thrombi from passing therethrough. 
     
     
         9 . The method of  claim 1 , wherein the attachment member includes a plurality of barbs configured to engage the interior wall of the LAA. 
     
     
         10 . The method of  claim 1 , wherein the plurality of strut wires are formed from a shape memory material. 
     
     
         11 . The method of  claim 1 , wherein the plurality of strut wires extend radially outward from the support. 
     
     
         12 . A medical apparatus for preventing atrial appendage thrombi from entering a blood stream, the medical apparatus comprising:
 an attachment member having a first diameter configured to be positioned within a cavity defined by an atrial appendage such that the attachment member engages a portion of an interior wall of the atrial appendage;   a mesh portion having a second diameter, a proximal portion and a distal portion, the mesh portion is configured to conform to an ostium of the atrial appendage;   a support having a diameter substantially smaller than the first diameter and the second diameter, and configured for coupling the attachment member and the mesh portion; and   wherein the attachment member includes a plurality of engagement members.   
     
     
         13 . The medical apparatus of  claim 12 , wherein the mesh portion is configured to allow blood to pass therethrough and inhibit thrombi from passing therethrough. 
     
     
         14 . The medical apparatus of  claim 12 , wherein the distal end of the plurality of engagement members includes a barb tip configured to engage the interior wall of the atrial appendage. 
     
     
         15 . The medical apparatus of  claim 12 , wherein the plurality of engagement members are formed from a shape memory material. 
     
     
         16 . The medical apparatus of  claim 12 , wherein the mesh portion is a woven portion formed from a shape memory material. 
     
     
         17 . The medical apparatus of  claim 12 , wherein the second diameter is greater than the first diameter. 
     
     
         18 . The medical apparatus of  claim 12 , wherein a filtering membrane is attached to the mesh portion, the filtering membrane configured to allow blood to pass therethrough and inhibit thrombi from passing therethrough. 
     
     
         19 . A method of delivering a medical apparatus for preventing atrial appendage thrombi from entering a blood stream, the method comprising:
 positioning the medical apparatus within a catheter apparatus wherein the catheter apparatus includes an outer sheath, and an inner member having a distal end portion, the inner member slidably receivable within an interior of the outer sheath, the medical apparatus comprising:
 an attachment member having a first diameter configured to be positioned within a cavity defined by an atrial appendage; 
 a mesh portion having a second diameter, a proximal portion and a distal portion; 
 a support having a diameter substantially smaller than the first diameter and the second diameter, and configured for coupling the attachment member and the mesh portion; 
   advancing the catheter apparatus to a position partially within the atrial appendage;   retracting the outer sheath longitudinally relative to the inner member to allow the engagement members to deflect radially outward and engage an interior wall of the atrial appendage; and   retracting the outer sheath longitudinally relative to the inner member further proximally to expose the mesh portion and allow the mesh portion to expand radially outward to conform to an ostium of the atrial appendage.   
     
     
         20 . The method of  claim 19 , wherein the second diameter is greater than the first diameter.