Temporary vascular filter

Abstract

The present invention provides a method of deploying a medical filter within a channel in a patient's body and filter systems which can be used in such a method. Such a filter may include a radially expandable body 52 having an opening 56 in a proximal length thereof. In one method, the filter is urged along a length of the channel with the filter body in a radially reduced configuration. This body is expanded to substantially fill the lumen of the vessel and orient the opening in the body proximally. Body fluid is permitted to enter the filter body through the proximally oriented opening and pass distally through the distal length of the body so that the distal length of the body filters from the body fluid particulate material entrained therein. The proximal length of the body can be drawn into the retrieval catheter, thereby effectively closing the proximally oriented opening within the catheter to retain the particulate material within the enclosure. In a preferred embodiment, the filter body 52 is formed of a porous, resilient fabric having pores therein and the proximal opening 56 is at least five times the size of such pores.

1 . Apparatus for filtering emboli from blood flowing through a vessel, the apparatus comprising: 
 a guide wire having a distal region and a stop on the distal region;    a capture ring disposed for translation on the guide wire, the stop limiting translation of the capture ring in a distal direction; and    a filter sac connected to the capture ring,    wherein, when the filter sac is deployed in the vessel, rotation or distal translation of the guide wire relative to the capture ring does not displace the filter sac, but retraction of the guide wire in a proximal direction causes the stop to abut against the capture ring.    
   
   
       2 . Apparatus for filtering emboli from blood flowing through a vessel, the apparatus comprising: 
 a guide wire having a first portion having a first diameter and a distal region having a second diameter greater than the first diameter; and    a filter element having a capture ring disposed for translation on the first portion, the capture ring having an aperture greater than the first diameter but smaller than the second diameter,    wherein rotation or distal translation of the guide wire relative to the capture ring does not displace the filter element.    
   
   
       3 . The apparatus of  claim 2  wherein the filter element comprises an expandable sac.  
   
   
       4 . The apparatus of  claim 2  wherein the guide wire further comprises a flange disposed on the distal region having a diameter larger than the diameter of the aperture in the capture ring.  
   
   
       5 . A method of filtering emboli from blood flowing through a vessel, the method comprising: 
 providing a guide wire having a distal region including a stop, and a filter element having a capture ring disposed for translation on the guide wire proximal of the stop;    transluminally inserting the guide wire and filter element into a vessel;    deploying the filter element to engage a wall of the vessel, the filter element filtering emboli out of blood flowing through the vessel;    advancing a treatment device along the guide wire to treat a portion of the vessel proximal to the location of the filter element, rotation or distal translation of the guide wire relative to the filter element imparted by the treatment device not displacing the filter element.    
   
   
       6 . The method of  claim 5  further comprising: 
 providing a delivery sheath; and compressing the filter element to a contracted state to insert the filter element within the delivery sheath.    
   
   
       7 . The method of  claim 5  wherein the filter element comprises an expandable sac, and deploying the filter element comprises expanding the expandable sac so that a perimeter of the expandable sac contacts the wall of the vessel.  
   
   
       8 . Apparatus for filtering emboli from blood flowing through a vessel, the apparatus comprising: 
 a guide wire having a distal region and a stop on the distal region;    a ring disposed for translation on the guide wire, the stop limiting translation of the ring in a distal direction; and    a filter connected to the ring,    wherein, when the filter is deployed in the vessel, rotation of the guide wire relative to the ring does not displace the filter, but retraction of the guide wire in a proximal direction causes the stop to abut against the ring.    
   
   
       9 . Apparatus for filtering emboli from blood flowing through a vessel, the apparatus comprising: 
 a guide wire having a first portion having a first diameter and a distal region having a second diameter greater than the first diameter; and    a filter element having a ring disposed for translation on the first portion, the ring having an aperture greater than the first diameter but smaller than the second diameter,    wherein rotation or distal translation of the guide wire relative to the ring does not displace the filter element.    
   
   
       10 . The apparatus of  claim 9  wherein the filter element comprises an expandable sac.  
   
   
       11 . A method of filtering emboli from blood flowing through a vessel, the method comprising: 
 providing a guide wire having a distal region including a stop, and a filter element having a ring disposed for translation on the guide wire proximal of the stop;    transluminally inserting the guide wire and filter element into a vessel;    deploying the filter element to engage a wall of the vessel, the filter element filtering emboli out of blood flowing through the vessel;    advancing a treatment device along the guide wire to treat a portion of the vessel proximal to the location of the filter element, rotation of the guide wire relative to the filter element imparted by the treatment device not displacing the filter element.    
   
   
       12 . The method of  claim 11  further comprising: 
 providing a delivery sheath; and compressing the filter element to a contracted state to insert the filter element within the delivery sheath.    
   
   
       13 . The method of  claim 11  wherein the filter element comprises an expandable sac, and deploying the filter element comprises expanding the expandable sac so that a perimeter of the expandable sac contacts the wall of the vessel.  
   
   
       14 . Apparatus for filtering emboli from blood flowing through a vessel, the apparatus comprising: 
 a guide wire having a distal region and a stop on the distal region;    a capture ring disposed for translation on the guide wire, the stop limiting translation of the capture ring in a distal direction; and    a self-expanding filter sac connected to the capture ring;    wherein, when the filter sac is deployed in the vessel, rotation or distal translation of the guide wire relative to the capture ring does not displace the filter sac, but retraction of the guide wire in a proximal direction causes the stop to abut against the capture ring.    
   
   
       15 . Apparatus for filtering emboli from blood flowing through a vessel, the apparatus comprising: 
 a guide wire having a first portion having a first diameter and a distal region having a second diameter greater than the first diameter; and    a self-expanding filter element having a capture ring disposed for translation on the first portion, the capture ring having an aperture greater than the first diameter but smaller than the second diameter,    wherein rotation or distal translation of the guide wire relative to the capture ring does not displace the filter element.    
   
   
       16 . The apparatus of  claim 15  wherein the filter element comprises an expandable sac.  
   
   
       17 . The apparatus of  claim 15  wherein the guide wire further comprises a flange disposed on the distal region having a diameter larger than the diameter of the aperture in the capture ring.  
   
   
       18 . A method of filtering emboli from blood flowing through a vessel, the method comprising: 
 providing a guide wire having a distal stop, and a filter element having a capture ring disposed for translation on the guide wire proximal of the stop;    transluminally inserting the guide wire and filter element into a vessel;    deploying the filter element to engage a wall of the vessel, the filter element filtering emboli out of blood flowing through the vessel;    advancing a treatment device along the guide wire to treat a portion of the vessel proximal to the location of the filter element, rotation or distal translation of the guide wire relative to the filter element not displacing the filter element.    
   
   
       19 . A method of filtering emboli from blood flowing through a vessel, the method comprising: 
 providing a guide wire having a distal stop, and a filter element having a ring disposed for translation on the guide wire proximal of the stop;    transluminally inserting the guide wire and filter element into a vessel;    deploying the filter element to engage a wall of the vessel, the filter element filtering emboli out of blood flowing through the vessel;    advancing a treatment device along the guide wire to treat a portion of the vessel proximal to the location of the filter element, rotation of the guide wire relative to the filter element not displacing the filter element.