US20030023263A1 - Apparatus and methods for aspirating emboli - Google Patents

Abstract

Apparatus and methods for aspirating emboli from a vascular filter or stent within a patient's circulatory system are provided. A filter sac of the vascular filter permits blood flow and captures emboli from the flow. The aspiration device removes emboli from within or proximal to the vascular filter or stent to reduce the risk to the ischemia during retrieval of the vascular filter and during a treatment procedure. Retrieval of the vascular filter may be accomplished using either the aspiration catheter or a separate retrieval catheter.

Description

FIELD OF THE INVENTION
• The present invention relates to apparatus and methods for aspirating emboli. More particularly, the present invention provides apparatus useful for aspirating emboli from a vascular device such as a vascular filter used to prevent embolization associated with diagnostic or therapeutic interventional procedures, thrombectomy and embolectomy.[0001]
BACKGROUND OF THE INVENTION
• Percutaneous interventional procedures to treat occlusive vascular disease, such as angioplasty, atherectomy, and stenting, often dislodge material from the vessel walls. This dislodged material, known as emboli, enters the bloodstream and may be large enough to occlude smaller downstream vessels, potentially blocking blood flow to tissue. The resulting ischemia poses a serious threat to the health or life of a patient if the blockage occurs in critical tissue, such as the heart, lungs, or brain.[0002]
• The deployment of stents and stent-grafts to treat vascular disease, such as aneurysms, involves the introduction of foreign objects into the bloodstream, and also may result in the formation of clots or release of emboli. Such particulate matter, if released into the bloodstream, also may cause infarction or stroke.[0003]
• Numerous blood filters have been designed to capture material liberated from vessel walls during the treatment of vascular disease. Such treatment procedures, such as angioplasty, typically involve transluminally inserting an interventional device, such as an angioplasty catheter, to the treatment site along a guidewire. During a typical interventional angioplasty treatment procedure, the balloon of the angioplasty catheter is inflated within the vessel at least once but often more than once. First a pre-dilatation angioplasty catheter is inflated against the vessel to pre-dilate it. Next a stent delivery angioplasty catheter is inflated to deploy the stent. Finally a post-dilation angioplasty catheter is inflated to properly seat the stent against the vessel. Each of the inflations and manipulations of the interventional devices often liberate emboli from the vessel walls. The emboli enters the bloodstream and flows into a vascular filter, where it remains for the duration of the treatment procedure.[0004]
• Is has been postulated that a vascular filter may become occluded with emboli during a transluminal diagnostic or therapeutic procedure, thus occluding flow of blood through the filter. Additional emboli, generated proximal to the vascular filter by the angioplasty catheter, may then be unable to flow downstream and into the vascular filter. When the vascular filter is collapsed for retrieval, the restored flow of blood through the vessel may carry those additional emboli downstream past the collapsed filter, potentially jeopardizing the patient's health.[0005]
• An additional disadvantage postulated to occur when retrieving an emboli-ladened vascular filter is that the vascular filter may become entangled with a stent disposed within the patient's vessel. If, for example, a stent has been deployed, the vascular filter may inadvertently engage a stent strut, preventing further advancement of the vascular filter within the vessel, or even possibly causing vessel dissection.[0006]
• Also, emboli may temporarily adhere to stents disposed within a patient's vessel. When blood flow is subsequently restored, the emboli may re-enter the bloodstream and cause infarction or stroke.[0007]
• In view of the foregoing, it would be desirable to provide improved apparatus and methods for aspirating emboli from a blood vessel in which a vascular filter is used in conjunction with a transluminal diagnostic or therapeutic procedure and/or in which a stent is deployed.[0008]
SUMMARY OF THE INVENTION
• The present invention pertains to apparatus and methods for aspirating emboli from a blood vessel in which a vascular filter is used in conjunction with a transluminal diagnostic or therapeutic procedure and/or in which a stent is deployed. The risk associated with retrieving a vascular filter from a patient's vessel can be decreased by using an aspiration device that aspirates emboli from a blood vessel in which a vascular filter and/or a stent is placed.[0009]
• The aspiration recovery devices of the present invention are intended to remove emboli immediately adjacent to or contained within a filter sac of a vascular filter. Additionally, the aspiration device may be used to retrieve the vascular filter. Two families of aspiration recovery devices are provided: a single catheter type and telescoping dual catheter type. The single catheter type device uses one catheter both to aspirate emboli and retrieve a vascular filter. The telescoping dual catheter type device uses two catheters, with one catheter disposed inside the other, so that the inner catheter is used to aspirate emboli from a vascular filter and the outer catheter is used to retrieve the vascular filter.[0010]
• Both the single catheter and the telescoping dual catheter types of aspiration recovery devices may be over-the-wire devices or rapid exchange devices. Aspiration through the catheters may be accomplished using a syringe coupled to the catheter via a hemostatic valve, wherein retracting the plunger of the syringe aspirates and amount of blood from the patient in a range of about 10 ml to 50 ml. Alternatively, a vacuum hook-up, such as a standard suction port available in a hospital operating room, may be used.[0011]
• Both rapid exchange and over-the-wire aspiration recovery devices of the present invention may be used to aspirate emboli from within or proximal to a vascular filter liberated from a patient's vessel wall by an interventional device. Devices constructed in accordance with the present invention also may be used to aspirate emboli from the filter sac of a vascular filter during a procedure. Additionally, the present invention may be used to aspirate emboli from around a stent placed in a patient's vessel.[0012]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective view of a first previously known vascular filter suitable for use with the apparatus of the present invention;[0013]
• FIG. 2 is a perspective view of another previously known vascular filter suitable for use with the apparatus of the present invention;[0014]
• FIG. 3 is a side view of yet another vascular filter suitable for use with the apparatus of the present invention;[0015]
• FIG. 4A is a perspective view of an over-the-wire single catheter aspiration recovery device of the present invention;[0016]
• FIG. 4B is a perspective view of a rapid exchange single catheter aspiration recovery device of the present invention;[0017]
• FIG. 5A is a side sectional view of the distal end of a rapid exchange single catheter aspiration recovery device of the present invention;[0018]
• FIGS.[0019]5B-5C are cross sectional views of the aspiration recovery device of FIG. 5A;
• FIG. 5D is a side sectional view of the aspiration recovery device of FIG. 5A and a collapsed vascular filter;[0020]
• FIG. 6 is a perspective view of the distal end of another embodiment of the rapid exchange single catheter aspiration recovery device of the present invention;[0021]
• FIG. 7 is a side sectional view of the distal end of an over-the-wire single catheter aspiration recovery device of the present invention;[0022]
• FIGS.[0023]8A-8B are perspective views depicting a method of aspirating emboli and recovering a vascular filter using the aspiration recovery device of FIG. 7;
• FIG. 9 is a side sectional view of the distal end of another embodiment of the over-the-wire single catheter aspiration recovery device of the present invention;[0024]
• FIGS.[0025]10A-10D are perspective views depicting a method of aspirating emboli and recovering a vascular filter using a rapid exchange telescoping catheter aspiration recovery device of the present invention;
• FIG. 10E is a perspective view of the distal end of the aspiration recovery device of FIGS.[0026]10A-10D;
• FIG. 10F is a cross sectional view of the aspiration recovery device of FIGS.[0027]10A-10D;
• FIGS.[0028]11A-11B are perspective views of the distal end of another embodiment of the rapid exchange telescoping catheter aspiration recovery device of the present invention;
• FIG. 11C is a cross sectional view of the aspiration recovery device of FIGS.[0029]11A-11B;
• FIG. 12 is a perspective view of the distal end of yet another embodiment of the rapid exchange telescoping catheter aspiration recovery device of the present invention;[0030]
• FIGS.[0031]13A-13C are perspective views depicting a method of aspirating emobli and recovering a vascular filter using the aspiration recovery device of FIG. 12;
• FIG. 14 is a frontal view of the aspiration recovery device of FIG. 12;[0032]
• FIG. 15 is a perspective view of the distal end of an over-the-wire telescoping catheter aspiration recovery device of the present invention; and[0033]
• FIGS.[0034]16A-16C are perspective views depicting a method of aspirating emboli and recovering a vascular filter using the aspiration recovery device of FIG. 15.
DETAILED DESCRIPTION OF THE INVENTION
• The present invention is directed to apparatus and methods for aspirating emboli from a blood vessel in which a vascular filter and/or a stent is used and decreasing the risk associated with retrieving a vascular filter from a patient's vessel.[0035]
• A number of vascular filters are known for providing distal protection against embolization in conjunction with a transluminal diagnostic or therapeutic procedure, such as angioplasty. These filters generally are deployed distal to a vascular lesion prior to undertaking a diagnostic or therapeutic procedure, and are designed to filter emboli liberated during the procedure from the patient's blood. A brief description of a number of these filters is provided as context for advantages achievable using the apparatus of the present invention.[0036]
• FIG. 1 shows[0037]vascular filter10 described in U.S. Pat. No. 6,129,739 to Khosravi et al., which is incorporated herein in its entirety.Vascular filter10 includes articulated support hoop11 carrying blood-permeable element12. Support hoop11 is attached totube13 atpoint14, and permits guidewire15 to be rotated independently of support hoop11. Blood-permeable element12 filters emboli and other undesirable material from blood passing through the filter, while permitting blood cells to pass freely therethrough. When an interventional procedure, e.g., angioplasty or stenting, is completed,vascular filter10 is retrieved by partially withdrawing support hoop11 into the lumen of the interventional device (e.g., angioplasty catheter), and removing the catheter and vascular filter.
• FIG. 2 depicts another type of vascular filter suitable for use with the methods and apparatus of the present invention, and is described in U.S. Pat. No. 6,152,946 to Broome et al., which is incorporated herein by reference.[0038]Vascular filter20 includes a plurality of longitudinally-extendingribs21 formingframe22 that supportsmouth23. Cone-shapedfilter24 is coupled tomouth23.Ribs21 are coupled tocollar25, which is displaced distally alongguidewire26 to expand and deployframe22 andfilter24.Filter24 includesholes27 that permit blood to pass through the filter, while trapping emboli.Vascular filter20 is collapsed for retrieval by applying a load againstribs21 that causescollar25 to slide proximally, thereby closing the vascular filter.
• Referring now to FIG. 3, another vascular filter suitable for use with the apparatus and methods of the present invention is described.[0039]Vascular filter30 is described in detail in co-pending, commonly assigned U.S. patent application Ser. No. 09/764,774, filed Jan. 16, 2000, and is summarily described here.
• [0040]Vascular filter30 preferably includes self-expandingsupport hoop31 mounted onsuspension strut32, and supports blood-permeable element33. Blood-permeable element33 comprises a biocompatible polymeric material having a multiplicity of pores.Suspension strut32 is affixed atproximal end34 totube35, and positions supporthoop31 approximately concentric totube35 when disposed in a substantially straight length of vessel, but advantageously permits the support hoop to become eccentrically displaced relative to supporttube35 when the filter is deployed in a curved vessel.
• [0041]Distal end36 of blood-permeable element33 is illustratively mounted tonose cone37, which is in turn mounted totube35.Filter30 is mounted onguidewire38 betweenproximal stop39 and enlargedfloppy tip40 of the guidewire, which functions as a distal stop.Tube35 permits guidewire38 to rotate independently offilter30, thereby permittingfloppy tip40 of the guidewire to be directed within the vessel without causing blood-permeable element33 to become wrapped aroundguidewire38.
• The aspiration recovery devices of the present invention are intended to remove emboli proximal to or within a filter sac of a vascular filter, such as those described above in the context of FIGS.[0042]1-3. Additionally, the recovery devices may be used to retrieve the vascular filter. Two families of aspiration recovery devices are provided: a single catheter type and a telescoping dual catheter type. The single catheter type device uses one catheter both to aspirate emboli and retrieve a vascular filter. The telescoping dual catheter type device uses two catheters, with one catheter disposed inside the other, so that the inner catheter is used to aspirate emboli from a vascular filter and the outer catheter is used to retrieve the vascular filter.
• Both the single catheter and the telescoping dual catheter types of aspiration recovery devices may be over-the-wire devices or rapid exchange devices. As is well known, in an over-the-wire device, the guidewire is disposed within the entire length of the catheter, whereas in a rapid exchange device the guidewire is disposed only within a short portion at the distal end of the catheter.[0043]
• Referring now to FIG. 4A, an embodiment of an over-the-wire single catheter aspiration recovery device constructed in accordance with the principles of the present invention is described.[0044]Aspiration recovery device50 illustratively includessyringe53 withplunger54 andchamber55.Syringe53 is coupled toside port56 ofcatheter52.Catheter52 also includeshemostatic valve57.Catheter52 may be used for both aspiration of emboli and retrieval of a vascular filter, for example,vascular filter30 of FIG. 3.
• [0045]Syringe53 may be any existing syringe capable of inducing low pressure inchamber55 whenplunger54 is retracted, thereby creating a pressure gradient betweendistal end51 in the patient's vasculature andchamber55. This pressure gradient causes fluid and material, specifically blood and emboli, to be aspirated from a region within or proximal tovascular filter30 tochamber55 viacatheter52. The amount of blood removed from thepatient using syringe53 preferably is in a range of about 10 ml to 50 ml. The amount of blood aspirated tochamber55 at the completion of a treatment procedure is generally sufficiently small that no effort need by made to cleanse and reintroduce the blood to the patient's circulatory system. Alternatively, the blood removed from the body may be filtered and reintroduced to the patient, if desired.
• While FIG. 4A depicts an over-the-wire single catheter device,[0046]syringe53 also may be used in conjunction with an over-the-wire telescoping dual catheter device, described hereinafter. In addition, while the present invention is illustrated with a syringe as the aspiration inducer, it should be understood that any other suitable device that induces suction may be used, such as a standard suction port available in a hospital operating room.
• With respect to FIG. 4B, a rapid exchange embodiment of a single catheter aspiration recovery device is described.[0047]Aspiration recovery device60 includessyringe65 withplunger66 andchamber64 coupled atconnection63 toaspiration catheter62.Catheter62 may be used for both aspiration of emboli and retrieval of a vascular filter, such as those described above in FIGS.1-3.
• [0048]Syringe65 preferably is constructed as described above with respect tosyringe53 of FIG. 4A, and is actuated by retractingplunger66 proximally. When so retracted, fluid and emboli within or proximal tovascular filter30 are drawn into distal end61, throughcatheter62, and intochamber64, as described above for the embodiment of FIG. 4A.
• Both the rapid exchange and the over-the-wire aspiration recovery devices of the present invention may be used to aspirate emboli liberated from a patient's vessel wall by an interventional device, such as an angioplasty catheter, an atherectomy catheter, an embolectomy catheter, a vascular mapping catheter, stent delivery device or other diagnostic or therapeutic interventional device, from within or proximal to a vascular filter.[0049]
• Referring now to FIG. 5A, a rapid exchange single catheter[0050]aspiration recovery device70 is described.Catheter74 preferably is constructed of a thin biocompatible material, as described hereinabove, and has sufficient stiffness to permit the catheter to be pushed along a guide wire through curved vasculature within a patient's circulatory system, and will not collapse when the syringe is actuated. The distal end ofcatheter74 may include a radiopaque marker or may be entirely radiopaque. Radiopaque is understood to be capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids the user in determining the location of thedistal end catheter74. Radiopaque materials may include, but are not limited to, gold, platinum, tungsten alloy, and plastic material loaded with a radiopaque filler.
• [0051]Catheter74 optionally may includebent tip72, which has a rounded profile to risk the risk of injury to a patient's vessel, or inadvertently becoming entangled with a stent, as it is advanced toward a treatment area.Opening71 of tip72 (see FIG. 5D) provides a rounded profile that enhances trackability.Guidewire78 entersguidewire lumen77 proximally throughskive76 and exitscatheter74 throughdistal opening71, as illustrated in FIGS. 5B and 5C.
• In accordance with the principles of the present invention,[0052]catheter74 is used to aspirate emboli from a location proximal to a vascular filter, usingsyringe65 or other suitable suction source. Emboli are aspirated through opening71 tochamber64 ofsyringe65. Additionally,catheter74 may be moved slightly in the proximal and distal directions relative tovascular filter30 to vacuum up emboli disposed proximal tovascular filter30. Once the aspiration step is completed,catheter74 then may be advanced towardvascular filter30 to collapse and retrieve the vascular filter throughopening71. Alternatively, upon completion of the interventional procedure, guidewire78 and attachedvascular filter30 may be withdrawn proximally until the vascular filter engages and is caused to be collapsed withincatheter74.
• With respect to FIG. 6, the distal end of an alternative embodiment of a rapid exchange single catheter aspiration recovery device of the present invention is described.[0053]Device80 is substantially similar todevice70 of FIGS.5, except thatdevice80 includes anadditional aspiration hole83 to facilitate aspiration of emboli proximal to a vascular filter.Device70 may also include a radiopaque marker similar to that described above.
• Referring to FIGS. 7 and 8, the distal end of an over-the-wire single catheter[0054]aspiration recovery device90 is now described. Preferably,catheter94 is constructed as described hereinabove, and may include a radiopaque marker or may be entirely radiopaque to permit the viewing of the catheter using a fluoroscope.Catheter94 includes taperedtip92, wherein the leading edges are rounded to reduce the risk of vessel injury or stent entanglement.
• [0055]Catheter94 may be used to aspirate emboli from a location proximal tovascular filter30 usingsyringe53 as described above with respect to FIG. 4A. Emboli E that are both proximal to and withinvascular filter30 may travel proximally and enter aspiration holes93 ofcatheter94 when suction is induced through the catheter, for example, by actuating syringe53 (see FIG. 4A). After the aspiration step is completed,catheter94 may be advanced distally towardvascular filter30 to collapse and retrieve the vascular filter inopening95, or alternatively, guidewire91 and attachedvascular filter30 may be withdrawn proximally to retrieve the vascular filter into opening95 ofcatheter94.
• With respect to FIG. 9,[0056]device100 is substantially similar todevice90 of FIGS. 7 and 8, except thatdevice100 includesbump tip102 with opening101 to facilitate aspiration of emboli from a location proximal to a vascular filter and to collapse the vascular filter.Tip102 is rounded to reduce the risk of vessel injury or stent entanglement.
• With reference to FIGS.[0057]10A-10D, a rapid exchange telescoping catheteraspiration recovery device110 is described.Device110 includesaspiration catheter112 disposed within a lumen ofretrieval catheter113. Preferably,aspiration catheter112 andretrieval catheter113 are constructed as described hereinabove for previous catheter embodiments and may include a radiopaque marker.
• [0058]Distal end114 ofaspiration catheter112 is configured to reduce the risk of becoming entangled with a stent disposed within a patient's vessel.Distal end114 includes roundededge117 disposed atangle116 to facilitate movement through the vessel, and to improve maneuverability ofcatheter112 by creating a leading edge to track through the vessel.Angle116 preferably is less than90-degrees, resulting inoblique opening115 ofdistal end114.
• In FIGS.[0059]10A-10D, a method for aspirating emboli and retrieving a vascular filter is illustrated. FIG. 10A illustrates a step of a treatment procedure, whereinvascular filter30 is disposed at a distal end ofguidewire111 followed byaspiration catheter112 andretrieval catheter113. FIG. 10F depicts guidewire111 disposed within a guide wire lumen ofretrieval catheter113, and externally toaspiration catheter112. At the conclusion of an interventional procedure, the interventional device is removed andaspiration recovery catheter110 then is advanced alongguidewire111 to a position just proximal ofvascular filter30.
• As depicted in FIG. 10B,[0060]aspiration catheter112 is advanced distally throughmouth41 and into blood-permeable element33 ofvascular filter30. Suction is then applied to the proximal end ofcatheter112 to aspirate emboli E from within blood-permeable element33 intoopening115, and throughaspiration catheter112.Aspiration catheter112 also may be moved in small distances back and forth within blood-permeable element33 to permitdistal end114 to unburdenvascular filter30.
• As shown in FIG. 10C,[0061]aspiration catheter112 then is retracted proximally intoretrieval catheter113. In FIG. 10D,retrieval catheter113 then is advanced distally to encapsulatevascular filter30.Catheters112 and113, guidewire111 andvascular filter30 may then be removed from the patient's vasculature. Alternatively, guidewire111 and attachedvascular filter30 may be withdrawn proximally intoretrieval catheter113.
• With respect to FIGS.[0062]11A-11C, another embodiment of the rapid exchange telescoping catheter aspiration recovery device of the present invention is described.Device120 is substantially similar todevice110 of FIGS.10, except thatdevice120 also includesnose cone122, one or more aspiration holes126,aspiration hole125, andinner catheter123 is keyed to outer catheter124 (see FIG. 11C).
• [0063]Nose cone122 facilitates tracking through a patient's vessel, and preferably includes roundedtip121, which reduces the risk of vessel injury or stent entanglement. Advancingaspiration catheter123 from withinretrieval catheter124 toward a vascular filter, such asvascular filter30, exposes aspiration holes125 and126, as shown in FIG. 1B, which as otherwise covered byretrieval catheter124 asdevice120 travels towardvascular filter30. This arrangement reduces the risk that aspiration holes125 and126 will become entangled with a stent strut asdevice120 is advanced toward a treatment site alongguidewire111.
• As shown in FIG. 11C,[0064]catheter123 is keyed withincatheter124 to maintain relative alignment of the catheters. This ensures that the aspiration catheter is at a proper orientation when entering a vascular filter, such asvascular filter30.
• FIGS.[0065]12-14 show yet another embodiment of the rapid exchange telescoping catheter aspiration recovery device of the present invention.Device130 is substantially similar todevice120 of FIGS.11, except thatdevice130 includesdistal end132 withaspiration holes133 and134, rather than a nose cone and aspiration holes that are hidden by a retrieval catheter.
• In FIGS.[0066]13A,vascular filter30 is disposed at a distal end ofguidewire111 followed byaspiration catheter135 andretrieval catheter131. This arrangement may be used to aspirate emboli E fromvascular filter30 following a treatment procedure such as angioplasty involving an interventional device such as an angioplasty catheter (not shown) andvascular filter30.
• In FIG. 13B,[0067]aspiration catheter135 is moved distally throughmouth41 and into blood-permeable element33 ofvascular filter30, and suction is drawn on the proximal end ofaspiration catheter133 to aspirate emboli E from within blood-permeable element33. In FIG. 13C,aspiration catheter135 then is retracted proximally to exitvascular filter30, andretrieval catheter131 is advanced distally to retrievevascular filter30. Alternatively, guidewire111 and attachedvascular filter30 may be withdrawn proximally until the vascular filter is retrieved withincatheter131.
• FIGS.[0068]15-16C show over-the-wire telescoping catheteraspiration recovery device140.Device140 includesaspiration catheter145 withaspiration holes143 and slit144 andretrieval catheter146. Preferably,aspiration catheter145 andretrieval catheter146 are constructed as described hereinabove, and are used in a method similar to that ofcatheters112 and113 of FIGS. 10.
• The present invention describes a method of aspirating emboli from a filter sac of a vascular filter prior to retrieval. However, a similar method may be used to aspirate emboli from the filter sac of the vascular filter during a procedure (not shown), for example, in the event that the sac of the vascular filter fills to capacity during a treatment procedure. Additionally, the present invention may be used to aspirate emboli from around a stent which may be in place within a patient's vessel.[0069]
• Although preferred illustrative embodiments of the present invention are described above, it will be evident to one skilled in the art that various changes and modifications may be made without departing from the invention. It is intended in the appended claims to cover all such changes and modifications that fall within the true spirit and scope of the invention.[0070]

Claims (27)

What is claimed is:

1. Apparatus for filtering and aspirating emboli from a vessel comprising:

a vascular filter having a blood-permeable element disposed on a guidewire, the vascular filter causing emboli to become deposited in the vessel in the vicinity of the vascular filter;

a first catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings,

wherein the first catheter is adapted to be advanced along the guidewire to a location in the vessel in the vicinity of the vascular filter to aspirate emboli.

2. The apparatus ofclaim 1 wherein the distal end of the first catheter is dimensioned so that the distal opening enters the blood-permeable element.

3. The apparatus ofclaim 1 wherein the distal opening of the first catheter is dimensioned so that the vascular filter may be at least partially retracted in the lumen of the first catheter.

4. The apparatus ofclaim 1 wherein the distal end of the first catheter is curved.

5. The apparatus ofclaim 1 wherein the distal end of the first catheter includes one or more aspiration holes disposed proximal of the distal opening.

6. The apparatus ofclaim 1 wherein the first catheter comprises a rapid exchange device.

7. The apparatus ofclaim 1 wherein the first catheter comprises an over-the-wire device.

8. The apparatus ofclaim 1 further comprising a second catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings, the lumen of the second catheter dimensioned to accept the first catheter therein.

9. The apparatus ofclaim 8 wherein the first catheter includes one or more aspiration holes disposed proximal of the distal opening and the second catheter selectively occludes the one or more aspiration holes.

10. The apparatus ofclaim 8 wherein the distal opening of the second catheter is dimensioned so that the vascular filter may be at least partially retracted in the lumen of the second catheter.

11. A method of aspirating emboli from a vessel comprising:

delivering a vascular filter having a blood-permeable element to a treatment site within a vessel so that emboli become deposited in the vessel in the vicinity of the vascular filter;

providing a first catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings;

advancing the first catheter to a location in the vessel so that the distal opening is in close proximity to the vascular filter; and

inducing suction at the proximal opening to aspirate emboli from the vessel through the distal opening into the lumen of the first catheter.

12. The method ofclaim 11 further comprising, while inducing suction, moving the first catheter slightly proximally and distally relative to the vascular filter.

13. The method ofclaim 11 further comprising, while inducing suction, advancing the distal end and distal opening of the first catheter within the vascular filter.

14. The method ofclaim 11 further comprising advancing the first catheter to retrieve at least a portion of the vascular filter through the distal opening and into the lumen of the first catheter.

15. The method ofclaim 11 further comprising:

providing a second catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings; and

advancing the second catheter over the first catheter to retrieve at least a portion of the vascular filter through the distal opening and into the lumen of the second catheter.

16. A method of aspirating emboli from a vessel in the vicinity of a stent, comprising:

delivering a vascular filter having a blood-permeable element to a treatment site within a vessel so that emboli become deposited in the vessel in the vicinity of the vascular filter;

delivering a stent into the vessel at a location proximal of the vascular filter;

providing a first catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings;

advancing the first catheter to a location in the vessel so that the distal opening is in close proximity to the stent; and

inducing suction at the proximal opening to aspirate emboli from the vessel through the distal opening into the lumen of the first catheter.

17. The method ofclaim 16 further comprising, while inducing suction, moving the first catheter slightly proximally and distally relative to the stent.

18. The method ofclaim 16 further comprising, while inducing suction, advancing the distal end and distal opening of the first catheter within the stent.

19. The method ofclaim 16 further comprising advancing the first catheter to retrieve at least a portion of the vascular filter through the distal opening and into the lumen of the first catheter.

20. The method ofclaim 16 further comprising:

providing a second catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings; and

advancing the second catheter over the first catheter to retrieve at least a portion of the vascular filter through the distal opening and into the lumen of the second catheter.

21. An intravascular aspiration system, comprising:

a first catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings;

a guidewire; and

wherein the first catheter is adapted to be advanced along the guidewire to a location in a blood vessel to aspirate emboli.

22. The system ofclaim 21, further comprising a vascular filter disposed on the guidewire, the vascular filter including a blood-permeable element.

23. The system ofclaim 22, wherein a nose cone is coupled to the blood-permeable element.

24. The system ofclaim 21 wherein the distal end of the first catheter includes one or more aspiration holes disposed proximal of the distal opening.

25. The system ofclaim 21 further comprising a second catheter having proximal and distal ends, proximal and distal openings, and a lumen extending between the proximal and distal openings, the lumen of the second catheter dimensioned to accept the first catheter therein.

26. The system ofclaim 25 wherein the first catheter includes one or more aspiration holes disposed proximal of the distal opening and the second catheter selectively occludes the one or more aspiration holes.

27. The system ofclaim 21, further comprising a syringe coupled to a side port of the first catheter.

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