Guidewire filter and methods of use

Abstract

A filter system for temporary placement of a filter in an artery or vein. The filter system includes a guidewire that is first positioned across a lesion within a vessel. The guidewire may include a distal stop. A slideable filter is then advanced along the guidewire using an advancing mechanism, typically an elongate member slideable over the guidewire and contacting the filter. A capture sheath may be disposed about the filter during advancement. Once the filter is positioned downstream of the lesion, the capture sheath is withdrawn, allowing the filter to expand. Further distal advancement of the filter is prohibited by the stop. After expansion of the filter, the capture sheath and the advancing mechanism are withdrawn from the region of interest, and removed from the patient's vessel. The filter may then be retrieved using a capture sheath or exchanged for a second filter after removing the first filter.

What is claimed is:  
     
         1 . A removable vascular filter system comprising: 
 an elongate wire having distal and proximal ends;    a filter membrane having a distal portion and a proximal free end portion, wherein said distal portion is pivotably attached to the elongate wire near said distal end of the elongate wire and wherein the proximal free end portion is substantially parallel to the elongate wire in its collapsed state and wherein said free end portion has a generally scalloped shape; and    deploying means for causing the filter to assume a position substantially normal to the longitudinal axis of the elongate wire;    
     
     
         2 . The vascular filter system of  claim 1 , whereby the deploying means comprises a control mechanism operable from the proximal end of the elongate wire and operatively connected to the filter membrane.  
     
     
         3 . The vascular filter system of  claim 1 , wherein the filter membrane is comprised of a porous mesh, and the scalloped shape is comprised of rounded sections.  
     
     
         4 . The vascular system of  claim 3 , wherein the pore size of the porous mesh is about 50-300 microns.  
     
     
         5 . The vascular system of  claim 3 , wherein the pore size of the porous mesh is about 20-500 microns.  
     
     
         6 . A method for protecting a patient during an endoluminal procedure, comprising the steps of: 
 providing a filter comprising an elongate wire having distal and proximal ends, and a filter membrane having a distal portion and a proximal free end portion, wherein said distal portion is pivotably attached to the elongate wire near said distal end of the elongate wire and wherein the proximal free end portion is substantially parallel to the elongate wire in its collapsed state and wherein said free end portion has a generally scalloped shape;    advancing the filter to a region of interest within a vessel;    expanding the filter membrane within the region of interest; and    performing an endoluminal procedure at the region of interest, wherein released embolic material is captured by the filter.    
     
     
         7 . The method of  claim 6 , wherein the filter membrane is expanded downstream of the region of interest.  
     
     
         8 . The method of  claim 6 , wherein the filter further comprises a deploying means to hold the filter membrane in a collapsed condition.  
     
     
         9 . The method of  claim 8 , wherein the deploying means is a sleeve.  
     
     
         10 . The method of  claim 9 , wherein the step of expanding the filter further comprises the step of proximally displacing the sleeve from the filter.  
     
     
         11 . The method of  claim 6 , wherein the vessel is a carotid artery.  
     
     
         12 . The method of  claim 6 , wherein the vessel is a coronary artery.  
     
     
         13 . The method of  claim 6 , wherein the step of performing an endoluminal procedure comprises the step of performing angioplasty.  
     
     
         14 . The method of  claim 6 , wherein the step of performing an endoluminal procedure comprises the step of placing a stent within the region of interest.