US 7226464 B2
A filter retrieval device having an actuatable dilator tip for retrieval of an intravascular filter from a body lumen is disclosed. An outer shaft coupled to a distal sheath is advanced along a filter wire to desired point within the vasculature. An intravascular filter such as a distal protection filter can be advanced along the filter wire to a point distal a lesion to collect debris dislodged during a medical procedure. Disposable in part within the distal sheath is an actuatable dilator tip adapted to retrieve the filter at least in part within the distal sheath. Actuation of the dilator tip may be accomplished by any number of means, including a resilient member such as a spring coil, or by a reduced inner diameter portion disposed on the distal sheath adapted to engage a plurality of recessed surfaces disposed on the dilator tip.
1. A filter system, comprising:
a wire having a proximal end and a distal end;
a filter for collecting debris from a body lumen, said filter being disposed proximal of the distal end of said wire;
an outer shaft having a proximal end, a distal end, and a distal sheath extending distally thereof;
a dilator tip slidably disposed in the distal sheath and movable between a distally advanced position located at least in part beyond the distal sheath, and a proximally retracted position; and
a spring coil adapted to bias the dilator tip in the distally advanced position.
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12. A device for removing an intravascular filter from a body lumen, comprising:
an outer shaft having a proximal end, a distal end, and a distal sheath extending distally thereof;
a dilator tip slidably disposed along a filter wire at least in part distally of the distal sheath; and
a spring coil disposed along the filter wire proximal the dilator tip, said spring coil adapted to bias the dilator tip toward the distal end of the distal sheath.
The present application claims the benefit of U.S. Provisional Application Ser. No. 60/272,657, filed on Mar. 1, 2001.
The present invention relates generally to the field of embolic protection devices. More specifically, the present invention pertains to retrieval devices for intravascular filters.
Intravascular filters such as embolic protection filters are generally placed within a body lumen, such as an artery or vein, downstream of a site where a therapeutic device will be used. Examples of procedures employing such filters include angioplasty, atherectomy, thrombectomy and stent placement. These procedures typically involve transluminally inserting and delivering within the artery or vein, a filter wire and filter to a location distal a coronary lesion. Once in place, a therapeutic device such as an angioplasty balloon or an atherectomy catheter can be advanced to the site of the lesion to perform the procedure. During the procedure, embolic material such as plaque or thrombus become dislodged from the walls of the body lumen, and flow downstream where they are collected by the filter. After the procedure is performed, the therapeutic device and filter containing the debris, if any, can be removed from the body.
The present invention relates generally to the field of embolic protection devices. More specifically, the present invention pertains to retrieval devices for intravascular filters. In one embodiment in accordance with the present invention, a filter retrieval device includes a distal sheath and an outer shaft extending proximally therefrom. A dilator tip is biased toward the distal end of the distal sheath by a resilient member. In one particular implementation, the resilient member may include a spring coil having one or more coils helically disposed along the filter wire. In an alternative implementation, the resilient member may include a spring having one or more struts longitudinally disposed along the filter wire. In use, the filter retrieval device is advanced along the filter wire until the dilator tip contacts a proximal filter stop. The filter retrieval device is then further advanced such that the filter collapses and is contained at least in part within the distal sheath.
In a similar embodiment, a filter retrieval device comprises a distal sheath and an outer shaft extending proximally therefrom, an actuatable dilator tip, and an inner shaft disposed at least in part within the lumen formed by the distal sheath. As with the aforementioned embodiment, the dilator tip is biased toward the distal end of the distal sheath by a resilient member such as a spring coil. The inner shaft may have a length substantially similar to the length of the outer shaft. Alternatively, the inner shaft may have a length substantially shorter than the length of the outer shaft. In the latter case, an exchange port can be disposed on the outer shaft to permit single operator advancement of the filter retrieval device.
In another embodiment of the present invention, a filter retrieval device comprises a distal sheath, a shaft, and a dilator tip slidably disposable along a filter wire. The distal sheath has a reduced inner diameter portion adapted to engage a recessed surface disposed on a portion of the dilator tip. In one particular implementation, the recessed surface includes a first recessed surface disposed on a proximal portion of the dilator tip, and a second recessed surface disposed on the dilator tip distal the first recessed surface. Prior to use, the operator attaches the dilator tip to the distal sheath by engaging the reduced inner diameter portion along the first recessed surface. To retrieve the filter, the operator then advances the device along the filter wire until the distal end of the dilator tip contacts the filter stop. Once the dilator tip is attached to the filter stop, further advancement of the dilator tip causes the reduced inner diameter portion of the distal sheath to engage the second recessed surface on the dilator tip. Continued advancement of the dilator tip causes the filter to retract at least in part within the distal sheath. A third recessed surface disposed on the dilator tip distal the second recessed surface may be utilized to provide the operator with tactile feedback that the filter has been retracted into the distal sheath a sufficient distance to permit removal from the body.
Referring now to the drawings wherein like reference numerals refer to like elements throughout the several views,
As shown in
Catheter 10 further includes an inner shaft 16 disposable at least in part within lumen 40 formed by distal sheath 12. Inner shaft 16 exits catheter 10 proximally at opening 18. In the particular embodiment shown in
Also disposed within distal sheath 12 is a dilator tip 28 and a spring coil 30. Dilator tip 28 has a generally circular cross section and conical-shaped distal end. Dilator tip 28 is biased at least in part out of the distal end of distal sheath 12 by spring coil 30. In the particular embodiment shown in
In use, for example, filter 22 is positioned in a body vessel distally of a location where a therapeutic device is to be used. In an application, filter 22 can be positioned distally of a coronary lesion. A therapeutic device such as an angioplasty catheter can be advanced over filter wire 20 to the lesion. Coronary angioplasty can be performed by the angioplasty catheter and debris dislodged by the procedure can be captured in filter 22. The angioplasty catheter can then be withdrawn. Catheter 10 can then be advanced over filter wire 20 until dilator tip 28 contacts filter stop 26. Catheter 10 can then be further advanced such that spring coil 30 is compressed and dilator tip 28 is drawn into lumen 40 of distal sheath 12. Catheter 10 is further advanced until filter 22 is disposed at least in part within distal sheath 12, as shown in
In an alternative embodiment to that shown in
A locking hub 144 disposed at or near the proximal end of the catheter is further provided to prevent relative motion between inner shaft 116 and outer shaft 114. Locking hub 144 may be attached to the inner and outer shafts by adhesive, solder or other attachment means, or by a releasable lock mechanism (not shown).
To retrieve the filter 22, outer shaft 114 is locked to inner sheath 116 by locking hub 144. Catheter 110 is advanced to a desired site in the body proximate and proximal filter 22. The catheter is then further advanced until dilator tip 128 attaches to filter stop 26. Once attached to filter stop 26, dilator tip 128 is retracted proximally, causing filter 22 to collapse at least in part within lumen 140 formed by distal sheath 112, as shown in
As shown in
Catheter 210 is used in a manner similar to that of catheters 10 and 110. For example, as illustrated in
An inner shaft 316 having a proximal end 346 and a distal end 348 is disposed within outer shaft 314 and distal sheath 312. The distal end 348 of inner shaft 316 may be attached to the proximal end of dilator tip 328 by adhesive or other attachment means.
Catheter 310 further includes a plunger assembly comprising a tubular member 352 defining a lumen 350, and a plunger 354 formed by enlarged diameter portion on the proximal end 346 of inner shaft 316. Plunger 354 is adapted to slide along filter wire 20 within lumen 350 formed by tubular member 352. A shaft 356 extending proximally from tubular member 352 is further disposed in part within lumen 350. A distal section 358 of shaft 356 is crimped in a smiley-face configuration to permit the filter wire 20 to exit catheter 310 through opening 360, and to act as a proximal stop for plunger 354. The proximal end of outer shaft 314, which extends proximally into lumen 350 formed by tubular member 352, is adapted to act as a distal stop for plunger 354.
In use, spring coil 330 biases the dilator tip 328 at least in part distally from distal sheath 312. To retrieve the filter, catheter 310 is advanced to a point along the filter wire 20 proximate and proximal filter stop 26. Catheter 310 is further advanced until dilator tip 328 attaches to filter stop 26. Once attached, filter wire 20 is retracted proximally, causing plunger 354 to slide proximally within tubular member 352, and filter 22 to collapse at least in part within distal sheath 312, as shown in
Spring coil 430 is adapted to bias the dilator tip 428 distally from distal sheath 412. As with the embodiment illustrated in
To retrieve the filter, catheter 410 is advanced along the filter wire 20 until dilator tip 428 contacts filter stop 26. Further advancement of catheter 410 causes the filter 22 to collapse within the lumen 440 of distal sheath 412, as shown in
Spring coil 530 is formed by a portion of a wire 560 that has a proximal end 562 and a distal end 564. The proximal end 562 of wire 560 is attached to outer shaft 514 at or near opening 518. Wire 560 is substantially straight from proximal end 562 to point 566, and is helically disposed about inner shaft 516 from point 566 to distal end 564.
In use, when catheter 530 is advanced distally, dilator tip 528 attaches to filter stop 26. Further advancement of the catheter causes filter 22 to collapse and retract at least in part into the distal sheath 512, as shown in
Although the particular embodiments depicted in
It is also to be understood that several different materials may be utilized to form the resilient members without deviating from the scope of the present invention. For example, the spring coil may be comprised of 304 or 316 grade stainless steel, or may be comprised of a polymeric material such as polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC) or polytetrafluoroethylene (PTFE).
Disposable at least in part within lumen 640 is a dilator tip 628. Dilator tip 628 is comprised of a substantially hard material, and includes several recessed surfaces adapted to permit relative motion between the dilator tip 628 and the distal sheath 612. In the particular embodiment shown in
The length of the second recessed surface can be varied depending on the actuation length desired. In an application, the length of the second recessed surface can be predetermined to provide a sufficient actuation length to permit the filter to completely collapse within the distal sheath. This pre-determined length provides the operator with feedback on the location of the filter within the distal sheath, thus obviating the need to resort to more traditional fluoroscopic imaging techniques.
To retrieve the filter, dilator tip 628 is first attached to the distal sheath 612 prior to insertion of the device into the body. In a first position shown in
In the particular embodiment shown in
In use, catheter 710 operates in a manner similar to that of catheter 610. For example, as illustrated in
In a similar embodiment to that shown in
Dilator tip 828 includes a first recessed surface 870 disposed on a proximal portion thereof, a second recessed surface 872 disposed distally the first recessed surface 870, and a third recessed surface 874 disposed distally the second recessed surface 872. In an application, the length of the second recessed surface 872 can be pre-determined to provide a sufficient actuation length to permit the filter to completely collapse within distal sheath 812.
To retrieve the filter, dilator tip 828 is attached to the distal sheath 812 and inserted into the patient. In a first position shown in
Referring now to
To retrieve filter 22 from the body lumen, a dilator tip 928 is advanced by means of a pushing member 984 along filter wire 20 through guide catheter 910 to a point proximate and proximal filter 22. As shown in
Retrieval of the filter 22 from the body lumen proceeds in a manner similar to that illustrated in
As shown in
Outer sheath 992 defines a lumen adapted to carry filter 22 in a collapsed state. A marking band (not shown) disposed about a distal portion of outer sheath 992 permits the operator to fluoroscopically judge the location of the outer sheath within the body.
Once filter 22 has been drawn into outer sheath 992, the dilator 928, filter wire 20, filter 22 and collected debris can be retracted through outer sheath 992 and guide catheter 910 and removed from the patient, as shown in
Having thus described the embodiments of the present invention, those of skill in the art will readily appreciate other alternative embodiments that may be employed which fall within the scope of the claims attached hereto. Numerous advantages of the invention covered by this document have been set forth in the foregoing description. It should be understood that the embodiments of the present invention are exemplary only. Changes may be made in details, particularly in matters of shape, size and arrangement of parts without exceeding the scope of the invention.
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