Methods for trapping emboli
A filter for filtering micro-emboli from a patient's blood during an angioplasty procedure is disclosed which comprises a plurality of curved wires connected to a rod between a first connector fixed with respect to the rod and a second connector slidingly mounted on the rod. Two layers of filter material are connected to opposite sides of the wires, and each layer includes perforations which are offset from the perforations in the other layer. When the rod and the wires are disposed within a catheter, the inner wall of the catheter compresses the wires toward the rod and when the rod is extended from the catheter, the wires resume their curved shape and pull the sliding connector along the rod toward the fixed connector.
1 . A method for performing treatment on a blockage in a vessel, comprising:
providing a rod, the rod carrying a radiopaque marker band and an expandable filter having a proximal end and a distal end;
providing a treatment catheter having a proximal end and a distal end;
delivering the rod to a location distal to a blockage;
expanding the filter adjacent the blockage;
delivering the treatment catheter such that the distal end of the treatment catheter is located near the blockage;
performing treatment on the blockage; and
removing the filter from the vessel;
wherein the radiopaque marker band indicates a proximalmost end of the filter throughout treatment.
2 . The method of claim 1 , wherein the radiopaque marker band remains proximal to the proximal end of the filter throughout treatment.
3 . The method of claim 1 , wherein the treatment comprises balloon angioplasty.
4 . The method of claim 1 , wherein the treatment comprises deploying a stent.
5 . The method of claim 1 , wherein the filter expands to a preformed shape.
6 . The method of claim 5 , wherein the expandable filter is expanded by retracting a catheter from over the expandable filter.
7 . The method of claim 5 , wherein the filter comprises a perforated material.
8 . The method of claim 1 , wherein the treatment catheter is a first treatment catheter, and further comprising:
providing a second treatment catheter having a proximal end and a distal end;
following removal of the first treatment catheter, delivering the second treatment catheter such that the distal end of the second treatment catheter is located near the blockage; and
performing a second treatment on the blockage.
9 . The method of claim 8 , wherein the second treatment comprises expanding a balloon to expand the blockage.
10 . The method of claim 8 , wherein the second treatment comprises deploying a stent.
11 . A method for performing treatment on a blockage in a vessel, comprising:
delivering a rod to a location distal to a blockage, the rod carrying an expandable filter thereon, such that the filter is distal to the blockage;
deploying the filter from a collapsed configuration to an expanded configuration;
performing treatment on the blockage with the filter expanded;
advancing a sheath distally over the rod so that the sheath at least partially covers and collapses the filter; and
removing the filter from the vessel with the filter at least partially within the sheath.
12 . The method of claim 11 , further comprising retracting a sheath to deploy the filter.
13 . The method of claim 12 , wherein the sheath to deploy the filter is a treatment catheter.
14 . The method of claim 12 , further comprising removing the sheath to deploy the filter from the vessel and advancing a treatment catheter over the rod.
15 . The method of claim 12 , wherein the sheath to deploy the filter and the sheath at least partially covering and collapsing the filter are the same sheath.
16 . The method of claim 11 , wherein the sheath extends at least to the distal end of the filter when the filter is removed from the vessel.
17 . The method of claim 11 , wherein the filter is deployed by expanding to a preformed shape.
18 . The method of claim 17 , wherein the filter comprises at least one sheet of perforated material.
19 . The method of claim 11 , wherein the filter has a proximal end coupled to a proximal band, and a distal end coupled to a distal band, at least one of the proximal bands and distal bands of the filter being slidable with respect to the rod.
20 . The method of claim 19 , wherein the distal band is slidable with respect to the rod.
21 . The method of claim 19 , wherein at least one of the distal bands and proximal bands comprises a radiopaque marker.
22 . The method of claim 11 , wherein the proximal end of the filter is indicated by a radiopaque marker band, the proximal marker band remaining proximal to the proximal end of the filter when the filter is in its expanded configuration.
23 . The method of claim 11 , wherein treatment is performed with a treatment catheter provided over the rod.
24 . The method of claim 23 , wherein the treatment catheter is removed from the vessel prior to advancing the sheath distally over the rod.
25 . The method of claim 11 , comprising performing at least two treatments on the blockage with two treatment catheters.
26 . The method of claim 11 , wherein the treatment comprises balloon angioplasty.
27 . A method for performing treatment on a blockage in a vessel, comprising:
providing a filter carried by a rod, the filter having a deployment configuration, an expanded configuration, and a retrieval configuration, the filter being in its deployment configuration within a sheath;
delivering the sheath and the filter to a location distal to the blockage;
retracting the sheath;
deploying the filter from its deployment configuration to its expanded configuration;
performing treatment on the blockage with the filter expanded;
advancing a sheath distally over the rod so that the sheath at least partially covers the filter in its retrieval configuration; and
removing the filter and the sheath from the vessel,
wherein the retrieval configuration is substantially the same as the deployment configuration.
28 . The method of claim 27 , wherein the filter expands to a preformed shape.
29 . The method of claim 27 , wherein the filter has a distal end and a proximal end and when the filter and the sheath are removed from the vessel, the sheath extends at least to the distal end of the filter.
30 . The method of claim 27 , wherein the filter has a distal end and a proximal end, the distal end being slidable such that the distal end of the filter moves towards the proximal end of the filter when the filter is deployed from its deployment configuration to its expanded configuration, and moves distally when the filter is collapsed from its expanded configuration to its retrieval configuration.
31 . The method of claim 27 , wherein the position of a proximalmost end of the filter on the rod is substantially the same in the retrieval configuration as the deployment configuration.
32 . The method of claim 27 , wherein the sheath used in the deployment configuration and the sheath used for retrieval are the same sheath.
33 . The method of claim 27 , wherein the sheath used in the deployment configuration and the sheath used for retrieval are separate sheaths.
34 . The method of claim 27 , wherein the treatment is performed with a treatment catheter.
35 . The method of claim 27 , wherein at least one of the sheaths used in the deployment configuration and the sheath used for retrieval is a treatment catheter.
36 . The method of claim 27 , wherein both of the sheaths used in the deployment configuration and the sheath used for retrieval are treatment catheters.
37 . A method for trapping emboli in a vessel of a patient, comprising:
providing a trapping apparatus comprising:
a rod having an axis and a distal end; and
a trapping element disposed adjacent the rod distal end, the trapping element having proximal and distal ends connected to the rod at spaced-apart locations, at least one of the proximal and distal ends of the trapping element being slidably connected to the rod; and
a structure coupled with the rod spaced from the proximal and distal ends of the trapping element to limit said slidability;
delivering the rod and the trapping element into the vessel of the patient;
expanding the trapping element within the vessel; and
performing treatment in the vessel, the trapping element capturing emboli resulting from the treatment.
38 . The method of claim 37 , wherein the structure comprises a stop mounted on the rod configured to limit movement of the trapping element along the rod.
39 . The method of claim 38 , wherein the stop is located distally of the trapping element.
40 . The method of claim 37 , wherein the structure is located between the proximal and distal ends of the trapping element.
41 . The method of claim 40 , wherein the structure comprises a safety wire attached to the rod.
42 . The method of claim 37 , wherein at least one of the proximal and distal ends of the trapping element comprises a radiopaque marker.
43 . The method of claim 42 , wherein the proximal end of the trapping element comprises a radiopaque marker, the radiopaque marker indicating a proximalmost end of the trapping element during treatment.
44 . The method of claim 37 , further comprising:
advancing a sheath distally over the rod such that the sheath at least partially covers the trapping element; and
removing the filter and the sheath from the vessel.