Method and device for filtering body fluid
Medical devices for filtering fluids flowing through a lumen and a method of forming medical devices. The devices can be used in vascular channels, urinary tracts, biliary ducts and the like, and filter emboli and other debris generated at a treatment site.
1. A method of protecting a patient from embolism during an intravascular procedure at a treatment site within a lumen defined by the wall of a vessel in a patient's vascular system comprising:
providing a delivery catheter having a lumen extending therethrough;
providing a filter device including a guidewire and a filter element mounted on the guidewire, the filter element having a distal end, the guidewire extending to at least the distal end of the filter element, the filter element being expandable from a collapsed delivery configuration when the filter element is retained within the lumen of the delivery catheter to an expanded deployed configuration when the filter element is deployed distally of a distal end of the delivery catheter, the filter element being collapsible from the expanded deployed configuration to a retrieval configuration for removal from the vessel, the filter element having a shape in the expanded configuration which defines a cavity having a proximally facing opening configured to filter emboli from blood when deployed in the vessel;
providing a retrieval catheter having a lumen extending therethrough and having a distal portion, the retrieval catheter sized to be accommodated within the vessel, the lumen of the retrieval catheter sized to accommodate the guidewire, the distal portion of the retrieval catheter being configured to accommodate the filter element in its retrieval configuration during removal of the retrieval catheter and filter element from the vessel;
introducing the delivery catheter into the lumen of the vessel;
advancing the guidewire through the lumen of the delivery catheter until the filter element is positioned at a desired location distal to the treatment site;
deploying the filter element to its expanded configuration prior to performing the intravascular procedure;
removing the delivery catheter from the vessel;
performing an intravascular procedure at the treatment site;
collapsing the filter element to its retrieval configuration after completion of the intravascular procedure;
advancing the retrieval catheter through the vessel over the guidewire until the filter element is accommodated by the retrieval catheter in its retrieval configuration; and
removing the retrieval catheter and filter element from the vessel.
2. The method of claim 1 wherein the intravascular procedure comprises balloon angioplasty.
3. The method of claim 1 wherein the intravascular procedure comprises an atherectomy.
4. A method of protecting a patient from embolism during an intravascular procedure at a treatment site within a lumen defined by the wall of a vessel in a patient's vascular system comprising:
providing a delivery catheter having a lumen extending therethrough;
providing a filter device including a filter element and means for carrying the filter element, the filter element having a distal end, the means for carrying extending to at least the distal end of the filter element, the filter element being expandable from a collapsed delivery configuration when the filter element is retained within the lumen of the delivery catheter to an expanded deployed configuration when the filter element is deployed distally of a distal end of the delivery catheter, the filter element being collapsible from the expanded deployed configuration to a retrieval configuration for removal from the vessel, the filter element having a shape in the expanded configuration which defines a cavity having a proximally facing opening configured to filter emboli from blood when deployed in the vessel;
providing a retrieval catheter having a lumen extending therethrough and having a distal portion, the retrieval catheter sized to be accommodated within the vessel, the lumen of the retrieval catheter sized to accommodate the carrying means, the distal portion of the retrieval catheter being configured to accommodate the filter element in its retrieval configuration during removal of the retrieval catheter and filter element from the vessel;
introducing the delivery catheter into the lumen of the vessel;
advancing the carrying means through the lumen of the delivery catheter until the filter element is positioned at a desired location distal to the treatment site;
deploying the filter element to its expanded configuration prior to performing the intravascular procedure;
removing the delivery catheter from the vessel;
performing an intravascular procedure at the treatment site;
collapsing the filter element to its retrieval configuration after completion of the intravascular procedure;
advancing the retrieval catheter through the vessel over the carrying means until the filter element is accommodated by the retrieval catheter in its retrieval configuration; and
removing the retrieval catheter and filter element from the vessel.
5. A method of filtering emboli at a desired site from blood flowing through the lumen of a patient's vessel using a filter system including an expandable filter, means for carrying the filter, a delivery catheter and a retrieval catheter, the method comprising:
introducing the delivery catheter into the lumen of the vessel;
advancing the carrying means through a lumen of the delivery catheter until the filter is positioned at the desired site;
expanding the filter in the lumen of the vessel;
removing the delivery catheter from the vessel;
filtering emboli from blood flowing through the lumen of the vessel at the desired site with the filter;
after the delivery catheter has been removed from the vessel introducing a distal end of the retrieval catheter through the lumen of the vessel over the carrying means;
advancing the retrieval catheter through the lumen of the vessel over the carrying means;
contracting the filter to a retrieval configuration; and
removing the carrying means and filter in its retrieval configuration with the retrieval catheter.
6. A method of filtering emboli at a desired site from blood flowing through the lumen of a patient's vessel using a filter system including a guidewire, an expandable filter carried by the guidewire, a delivery catheter and a retrieval catheter, the method comprising:
introducing the delivery catheter into the lumen of the vessel;
advancing the guidewire through a lumen of the delivery catheter until the filter is positioned at the desired site;
expanding the filter in the lumen of the vessel;
removing the delivery catheter from the vessel;
filtering emboli from blood flowing through the lumen of the vessel at the desired site with the filter;
after the delivery catheter has been removed from the vessel introducing a distal end of the retrieval catheter through the lumen of the vessel over the guidewire;
advancing the retrieval catheter through the lumen of the vessel over the guidewire;
contracting the filter to a retrieval configuration; and
removing the guidewire and filter in its retrieval configuration with the retrieval catheter.