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 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 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 balloon catheter having a proximal and a distal end and a proximal and distal region and a lumen which slidably receives the guidewire, the balloon catheter having an inflatable balloon associated with the distal region, the balloon having a first diameter which permits intraluminal delivery of the balloon catheter into the vessel and a second expanded diameter adapted to substantially engage the wall of 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;
advancing the balloon catheter through the vessel over the guidewire until the balloon is positioned at the treatment site;
inflating the balloon to perform the intravascular procedure;
capturing emboli released from the treatment site during the procedure in the cavity of the filter element as the emboli flows with blood through the opening in the filter element;
removing the balloon catheter from the vessel;
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, guidewire and filter element from the vessel.
2. The method of claim 1 wherein in the step of providing a balloon catheter the balloon catheter comprises the delivery catheter.
3. The method of claim 1 further comprising advancing the guidewire and the delivery catheter together through the lumen of the vessel.
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 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 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 balloon catheter having a proximal and a distal end and a proximal and distal region and a lumen which slidably receives the carrying means, the balloon catheter having an inflatable balloon associated with the distal region, the balloon having a first diameter which permits intraluminal delivery of the balloon catheter into the vessel and a second expanded diameter adapted to substantially engage the wall of 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;
advancing the balloon catheter through the vessel over the carrying means until the balloon is positioned at the treatment site;
inflating the balloon to perform the intravascular procedure;
capturing emboli released from the treatment site during the procedure in the cavity of the filter element as the emboli flows with blood through the opening in the filter element;
removing the balloon catheter from the vessel;
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, carrying means and filter element from the vessel.
5. A method of filtering emboli from blood flowing through the lumen of a patient's vessel during an intravascular procedure at a treatment site using a system including a guidewire, an expandable filter carried by the guidewire, a delivery catheter, a balloon catheter having an inflatable balloon, 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 a location distal to the treatment site;
expanding the filter in the lumen of the vessel;
removing the delivery catheter from the vessel;
advancing the balloon catheter over the guidewire until the balloon is at the treatment site;
inflating the balloon to perform the intravascular procedure;
filtering emboli from blood flowing through the lumen of the vessel with the filter during the intravascular procedure;
removing the balloon catheter from the vessel;
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.
6. The method of claim 5 further comprising advancing the guidewire and the delivery catheter together through the lumen of the vessel.