U.S. patent application number 11/033910 was filed with the patent office on 2005-06-02 for distal protection device and method.
Invention is credited to Adams, Daniel O., Broome, Thomas E., Cassell, Robert L., Daniel, John M.K., Holtan, David J..
Application Number | 20050119691 11/033910 |
Document ID | / |
Family ID | 25204805 |
Filed Date | 2005-06-02 |
United States Patent
Application |
20050119691 |
Kind Code |
A1 |
Daniel, John M.K. ; et
al. |
June 2, 2005 |
Distal protection device and method
Abstract
An emboli capturing system captures emboli in a body lumen. A
first elongate member has a proximal end and a distal end. An
expandable emboli capturing device is mounted proximate the distal
end of the first elongate member, and is movable between a radially
expanded position and a radially contracted position. When in the
expanded position, the emboli capturing device forms a basket with
a proximally opening mouth. A second elongate member has a proximal
and a distal end with a lumen extending therebetween. The lumen is
sized to slidably receive a portion of the first elongate member.
An expandable delivery device is mounted to the distal end of the
second elongate member and is movable from a radially retracted
position to a radially expanded position. The delivery device has a
receiving end configured to receive the emboli capturing device,
and retains at least the mouth of the emboli capturing device in a
radially retracted position.
Inventors: |
Daniel, John M.K.; (Hopkins,
MN) ; Broome, Thomas E.; (Hopkins, MN) ;
Holtan, David J.; (Rogers, MN) ; Cassell, Robert
L.; (Otsego, MN) ; Adams, Daniel O.; (Orono,
MN) |
Correspondence
Address: |
CROMPTON, SEAGER & TUFTE, LLC
1221 NICOLLET AVENUE
SUITE 800
MINNEAPOLIS
MN
55403-2420
US
|
Family ID: |
25204805 |
Appl. No.: |
11/033910 |
Filed: |
January 12, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11033910 |
Jan 12, 2005 |
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10346372 |
Jan 17, 2003 |
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6872216 |
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10346372 |
Jan 17, 2003 |
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10160450 |
May 30, 2002 |
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6663652 |
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10160450 |
May 30, 2002 |
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09735332 |
Dec 12, 2000 |
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09735332 |
Dec 12, 2000 |
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09409497 |
Sep 30, 1999 |
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6245089 |
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09409497 |
Sep 30, 1999 |
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08943358 |
Oct 3, 1997 |
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6001118 |
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08943358 |
Oct 3, 1997 |
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08810825 |
Mar 6, 1997 |
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5814064 |
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08810825 |
Mar 6, 1997 |
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08813794 |
Mar 6, 1997 |
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5827324 |
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61F 2/013 20130101;
A61F 2230/0086 20130101; A61F 2230/0006 20130101; A61B 17/22031
20130101; A61F 2/0108 20200501; A61F 2230/0021 20130101; A61F
2230/0076 20130101; A61B 2017/22042 20130101; A61F 2230/008
20130101; A61F 2250/0003 20130101; A61B 2017/22061 20130101; A61B
2017/2212 20130101; A61F 2/0105 20200501; A61F 2002/015 20130101;
A61F 2002/30092 20130101; A61F 2230/0067 20130101; A61B 2017/22038
20130101; A61B 2017/22049 20130101; A61B 2017/00539 20130101; A61B
17/221 20130101; A61F 2/014 20200501; A61M 2025/09183 20130101;
A61M 2025/09125 20130101; A61F 2002/018 20130101; A61F 2210/0014
20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 029/00 |
Claims
1-30. (canceled)
31. An embolic protection device, comprising: an elongate wire
having a proximal end and a distal end; and a filter eccentrically
coupled to the elongate wire proximal the distal end of the
elongate wire, the filter including a wire frame defining a
proximal opening and a filter mesh coupled to the wire frame;
wherein the filter is movable between an expanded position and a
contracted position.
32. The embolic protection device of claim 31, wherein the wire
frame comprises a radiopaque material.
33. The embolic protection device of claim 31, wherein the filter
is biased in the expanded position.
34. The embolic protection device of claim 31, wherein the filter
mesh includes a plurality of filaments.
35. The embolic protection device of claim 31, wherein the filter
mesh has a generally conical shape.
36. The embolic protection device of claim 31, wherein the filter
has a proximal end and a distal end, wherein the distal end is
coupled to the elongate wire.
37. The embolic protection device of claim 31, wherein the filter
is eccentrically coupled to the elongate wire such that the
proximal opening of the wire frame is disposed to one side of the
elongate wire.
38. The embolic protection device of claim 31, wherein the elongate
wire extends through the filter.
39. The embolic protection device of claim 38, wherein the filter
includes a distal end coupled to the elongate wire.
40. An embolic protection device, comprising: an elongate wire
having a proximal end and a distal end; and a generally conical
filter element having a proximal end and a distal end, the proximal
end defining a proximal opening and the distal end defining a
generally enclosed end; wherein the proximal end of the filter
element is coupled to the elongate wire such that the proximal
opening is not concentric with the elongate wire.
41. The embolic protection device of claim 40, wherein the filter
element includes a wire loop and a mesh coupled to the wire
loop.
42. The embolic protection device of claim 41, wherein the wire
loop includes a radiopaque material.
43. The embolic protection device of claim 41, wherein the mesh
includes a plurality of filaments.
44. The embolic protection device of claim 40, wherein the distal
end of the filter element is coupled to the elongate wire.
45. The embolic protection device of claim 40, wherein the filter
element is movable between an expanded position and a contracted
position.
46. The embolic protection device of claim 40, wherein the elongate
wire extends through the filter element.
47. An embolic protection device, comprising: a generally conical
filter having a proximal end and a distal end, the filter including
a wire frame adjacent the proximal end of the filter defining a
proximal opening and a filter mesh coupled to the wire frame; and
an elongate wire having a proximal end and a distal end, the
elongate wire extending through the filter and coupled to the wire
frame such that the proximal opening of the wire frame is not
concentric with the elongate wire.
48. The embolic protection device of claim 47, wherein the distal
end of the filter is coupled to the elongate wire.
49. The embolic protection device of claim 47, wherein the wire
frame includes a radiopaque material.
Description
[0001] This application is a continuation-in-part of co-pending
application Ser. No. 08/810,825 filed Mar. 6, 1997 entitled DISTAL
PROTECTION DEVICE, and assigned to the same assignee as the present
invention.
[0002] The following co-pending patent application is hereby
incorporated by reference U.S. patent application Ser. No.
08/813,794, entitled DISTAL PROTECTION DEVICE which was filed on
Mar. 6, 1997, and assigned to the same assignee as the present
application.
BACKGROUND OF THE INVENTION
[0003] The present invention deals with an emboli capturing system.
More specifically, the present invention deals with an emboli
capturing system and method for capturing embolic material in a
blood vessel during an atherectomy or thrombectomy procedure.
[0004] Blood vessels can become occluded (blocked) or stenotic
(narrowed) in one of a number of ways. For instance, a stenosis may
be formed by an atheroma which is typically a harder, calcified
substance which forms on the lumen walls of the blood vessel. Also,
the stenosis can be formed of a thrombus material which is
typically much softer than an atheroma, but can nonetheless cause
restricted blood flow in the lumen of the blood vessel. Thrombus
formation can be particularly problematic in a saphenous vein graft
(SVG).
[0005] Two different procedures have developed to treat a stenotic
lesion (stenosis) in vasculature. The first is to deform the
stenosis to reduce the restriction within the lumen of the blood
vessel. This type of deformation (or dilatation) is typically
performed using balloon angioplasty.
[0006] Another method of treating stenotic vasculature is to
attempt to completely remove either the entire stenosis, or enough
of the stenosis to relieve the restriction in the blood vessel.
Removal of the stenotic lesion has been done through the use of
radio frequency (RF) signals transmitted via conductors, and
through the use of lasers, both of which treatments are meant to
ablate (i.e., super heat and vaporize) the stenosis. Removal of the
stenosis has also been accomplished using thrombectomy or
atherectomy. During thrombectomy and atherectomy, the stenosis is
mechanically cut or abraded away from the vessel.
[0007] Certain problems are encountered during thrombectomy and
atherectomy. The stenotic debris which is separated from the
stenosis is free to flow within the lumen of the vessel. If the
debris flows distally, it can occlude distal vasculature and cause
significant problems. If it flows proximally, it can enter the
circulatory system and form a clot in the neural vasculature, or in
the lungs, both of which are highly undesirable.
[0008] Prior attempts to deal with the debris or fragments have
included cutting the debris into such small pieces (having a size
on the order of a blood cell) that they will not occlude vessels
within the vasculature. However, this technique has certain
problems. For instance, it is difficult to control the size of the
fragments of the stenotic lesion which are severed. Therefore,
larger fragments can be severed accidentally. Also, since thrombus
is much softer than an atheroma, it tends to break up easier when
mechanically engaged by a cutting instrument. Therefore, at the
moment that the thrombus is mechanically engaged, there is a danger
that it can be dislodged in large fragments which would occlude the
vasculature.
[0009] Another attempt to deal with debris severed from a stenosis
is to remove the debris, as it is severed, using suction. However,
it may be necessary to pull quite a high vacuum in order to remove
all of the pieces severed from the stenosis. If a high enough
vacuum is not used, all of the severed pieces will not be removed.
Further, when a high vacuum is used, this can tend to cause the
vasculature to collapse.
[0010] A final technique for dealing with the fragments of the
stenosis which are severed during atherectomy is to place a device
distal to the stenosis during atherectomy to catch the pieces of
the stenosis as they are severed, and to remove those pieces along
with the capturing device when the atherectomy procedure is
complete. Such capture devices have included expandable filters
which are placed distal of the stenosis to capture stenosis
fragments. Problems are also associated with this technique. For
example, delivery of such devices in a low profile, pre-deployment
configuration can be difficult. Further, some devices include
complex and cumbersome actuation mechanisms. Also, retrieving such
capture devices, after they have captured emboli, can be difficult
as well.
SUMMARY OF THE INVENTION
[0011] An emboli capturing system captures emboli in a body lumen.
A first elongate member has a proximal end and a distal end. An
expandable emboli capturing device is mounted proximate the distal
end of the first elongate member, and is movable between a radially
expanded position and a radially contracted position. When in the
expanded position, the emboli capturing device forms a basket with
a proximally opening mouth. A second elongate member has a proximal
and a distal end with a lumen extending therebetween. The lumen is
sized to slidably receive a portion of the first elongate member.
An expandable delivery device is mounted to the distal end of the
second elongate member and is movable from a radially retracted
position to a radially expanded position. The delivery device has a
receiving end configured to receive the emboli capturing device,
and retains at least the mouth of the emboli capturing device in a
radially retracted position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows a distal protection device of the present
invention in a deployed position.
[0013] FIG. 2 shows the distal protection device shown in FIG. 1 in
a collapsed position.
[0014] FIG. 3 shows an end view of a portion of the distal
protection device shown in FIGS. 1 and 2.
[0015] FIG. 4 shows a cross-sectional view of a portion of the
distal protection device shown in FIGS. 1-3 in the deployed
position.
[0016] FIG. 5 shows a second embodiment of the distal protection
device according to the present invention in a deployed
position.
[0017] FIG. 6 shows an end view of the distal protection device
shown in FIG. 5.
[0018] FIG. 7 shows a cross-sectional view of the distal protection
device shown in FIGS. 5 and 6 in the collapsed position.
[0019] FIG. 8 shows a third embodiment of a distal protection
device according to the present invention in a deployed
position.
[0020] FIG. 9 is a side sectional view of an alternate embodiment
illustrating how the expandable members of the present invention
are attached to a guidewire.
[0021] FIG. 10 is a sectional view taken along section lines 10-10
in FIG. 9.
[0022] FIGS. 11A and 11B show a fourth and fifth embodiment,
respectively, of a distal protection device according to the
present invention in a deployed position.
[0023] FIG. 12 illustrates the operation of a distal protection
device in accordance with the present invention.
[0024] FIGS. 13A-17B show additional embodiments of distal
protection devices which expand and collapse based on movement of a
mechanical actuator.
[0025] FIGS. 18A-18D illustrate an additional embodiment of a
distal protection device which is deployed and collapsed using a
rolling flap configuration.
[0026] FIG. 19 illustrates another embodiment in accordance with
the present invention in which the protection device is deployed
using fluid pressure and a movable collar.
[0027] FIGS. 20A and 20B illustrate another aspect of the present
invention in which two longitudinally movable members used to
deploy the distal protection device are disconnectably locked to
one another.
[0028] FIGS. 21A-21C illustrate another embodiment in accordance
with the present invention in which the protection device is formed
with a shape memory alloy frame and an attached filter or mesh
mounted to the frame.
[0029] FIGS. 22A-22C illustrate another embodiment in accordance
with the present invention in which the distal protection devices
shown in FIGS. 21A-21C are delivered and deployed.
[0030] FIGS. 23A-23E illustrate another embodiment in accordance
with the present invention in which the distal protection devices
shown in FIGS. 21A-21C are retrieved.
[0031] FIGS. 24A-24C illustrate another embodiment in accordance
with the present invention in which the distal protection devices
shown in FIGS. 21A-21C are retrieved.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] FIG. 1 illustrates protection device 10 in a deployed
position within the lumen of a blood vessel 12. Protection device
10 preferably includes hollow guidewire 14 (or a hypotube having
the same general dimensions as a guidewire) having a coil tip 16,
and a capturing assembly 18. Capturing assembly 18, in the
embodiment shown in FIG. 1, includes an inflatable and expandable
member 20 and mesh 22.
[0033] An interior of expandable member 20 is preferably coupled
for fluid communication with an inner lumen of guidewire 14 at a
distal region of guidewire 14. When deployed, inflatable member 20
inflates and expands to the position shown in FIG. 1 such that
capturing assembly 18 has an outer periphery which approximates the
inner periphery of lumen 12.
[0034] Mesh 22 is preferably formed of woven or braided fibers or
wires, or a microporous membrane, or other suitable filtering or
netting-type material. In one preferred embodiment, mesh 22 is a
microporous membrane having holes therein with a diameter of
approximately 100 .mu.m. Mesh 22 can be disposed relative to
inflatable member 20 in a number of different ways. For example,
mesh 22 can be formed of a single generally cone-shaped piece which
is secured to the outer or inner periphery of inflatable member 20.
Alternatively, mesh 22 can be formed as a spiral strip which is
secured about the outer or inner periphery of inflatable member 20
filling the gaps between the loops of inflatable member 20.
Alternatively, mesh 22 can be formed of a number of discrete pieces
which are assembled onto inflatable member 20.
[0035] Hollow guidewire 14 preferably has a valve 24 coupled in a
proximal portion thereof. During operation, a syringe is preferably
connected to the proximal end of guidewire 14, which preferably
includes a fluid hypotube. The syringe is used to pressurize the
fluid such that fluid is introduced through the lumen of hollow
guidewire 14, through valve 24, and into inflatable member 20. Upon
being inflated, inflatable member 20 expands radially outwardly
from the outer surface of guidewire 14 and carries mesh 22 into the
deployed position shown in FIG. 1. In this way, capturing assembly,
or filter assembly, 18 is deployed distally of stenosis 26 so that
stenosis 26 can be severed and fragmented, and so the fragments
from stenosis 26 are carried by blood flow (indicated by arrow 28)
into the basket or chamber formed by the deployed filter assembly
18. Filter assembly 18 is then collapsed and removed from vessel 12
with the fragments of stenosis 26 contained therein.
[0036] FIG. 2 illustrates protection device 10 with filter assembly
18 in the collapsed position. Similar items to those shown in FIG.
1 are similarly numbered. FIG. 2 illustrates that mesh 22 is easily
collapsible with inflatable member 20. In order to collapse filter
assembly 18, fluid is preferably removed from inflatable member 20
through the lumen of hollow guidewire 14 and through two-way valve
24. This can be done using the syringe to pull a vacuum, or using
any other type of suitable fluid removal system.
[0037] Inflatable member 20 is preferably formed of a material
having some shape memory. Thus, when inflatable member 20 is
collapsed, it collapses to approximate the outer diameter of hollow
guidewire 14. In one preferred embodiment, inflatable member 20 is
formed of a resilient, shape memory material such that it is
inflated by introducing fluid under pressure through the lumen in
hollow guidewire 14 into inflatable member 20. When pressure is
released from the lumen in hollow guidewire 14, inflatable member
20 is allowed to force fluid out from the interior thereof through
two-way valve 24 and to resume its initial collapsed position.
Again, this results in filter assembly 18 assuming its collapsed
position illustrated in FIG. 2.
[0038] FIG. 3 illustrates a view taken from the distal end of
device 10 with mesh 22 removed for clarity. FIG. 3 shows that, when
inflatable member 20 is deployed outwardly, mesh 22 (when deployed
between the loops of inflatable member 20) forms a substantially
lumen-filling filter which allows blood to flow therethrough, but
which provides a mechanism for receiving and retaining stenosis
fragments carried into mesh 22 by blood flow through the
vessel.
[0039] FIG. 3 also shows that inflatable member 20 preferably has a
proximal end portion 29 which is connected to the outer periphery
of guidewire 14. Although end 29 need not be connected to guidewire
14, it is preferably connected using adhesive or any other suitable
connection mechanism. By fixedly connecting proximal end portion 29
to guidewire 14, this increases the stability of the filter
assembly 18 upon deployment.
[0040] FIG. 4 is a cross-sectional view of a portion of protection
device 10. FIG. 4 shows protection device 10 with filter assembly
18 in the expanded or deployed position. FIG. 4 also better
illustrates that guidewire 14 is hollow and has a longitudinal
lumen 30 extending therethrough. Longitudinal lumen 30 is connected
in fluid communication with an interior of inflatable member 20
through aperture 32 which is provided in the wall of guidewire 14.
FIG. 4 also shows that, in one preferred embodiment, a core wire 34
extends through lumen 30 from a proximal end thereof where it is
preferably brazed to a portion of a hypotube which may be connected
to the proximal portion of guidewire 14. The core wire 34 extends
to the distal end of guidewire 14 where it is connected to coil tip
16. In one preferred embodiment, coil tip 16 is brazed or otherwise
welded or suitably connected to the distal portion of core wire
34.
[0041] FIG. 4 further shows that, in the preferred embodiment,
inflatable member 20 inflates to a generally helical, conical shape
to form a basket opening toward the proximal end of guidewire 14.
FIG. 4 further illustrates, in the preferred embodiment, mesh 22
has a distal portion 38 which is connected to the exterior surface
of guidewire 14, at a distal region thereof, through adhesive 36 or
any other suitable connection mechanism.
[0042] FIG. 5 illustrates a second embodiment of a distal
protection device 40 in accordance with the present invention.
Device 40 includes hollow guidewire 42, filter assembly 44 and coil
tip 16. Filter assembly 44 includes a plurality of inflatable
struts 46 and mesh 47. Each strut 46 has a distal end 48 and
proximal end 50. Inflatable struts 46 also have an interior which
is coupled in fluid communication, through distal end 48 thereof,
with the lumen in hollow guidewire 42. Struts 46 are preferably
configured such that, upon being inflated, the proximal ends 50
deploy radially outwardly away from the outer surface of hollow
guidewire 42 to assume a dimension which approximates the inner
dimension of lumen 58 in which they are inserted.
[0043] Mesh 47, as with mesh 22 shown in FIG. 1, is deployed either
on the outer or inner surface of inflatable struts 46, such that,
when the inflatable struts 46 are deployed radially outwardly, mesh
47 forms a generally conical basket opening toward the proximal end
of hollow guidewire 42. As with the embodiment shown in FIG. 1,
mesh 47 can be applied to either the outer or the inner surface of
struts 46. It can be applied to struts 46 as one unitary conical
piece which is adhered about distal ends 48 of struts 46 using
adhesive (or about the distal end of guidewire 42 using adhesive)
and secured to the surface of the struts 46 also using adhesive.
Alternatively, mesh 47 can be applied to struts 46 in a plurality
of pieces which are individually or simultaneously secured to, and
extend between, struts 46.
[0044] FIG. 6 is an end view of distal protection device 40 shown
in FIG. 5 taken from the distal end of distal protection device 40.
When struts 46 are deployed outwardly, mesh 47 forms a
substantially lumen-filling filter which allows blood to flow
therethrough, but which provides a mechanism for receiving and
retaining stenosis fragments from stenosis 56 carried into mesh 47
by blood flow through the vessel.
[0045] FIG. 7 is a cross-sectional view of a portion of distal
protection device 40 shown in FIGS. 5 and 6. FIG. 7 shows filter
assembly 44 in the collapsed position in which it approximates the
outer diameter of guidewire 42. FIG. 7 also shows that, in the
preferred embodiment, the distal ends 48 of struts 46 are in fluid
communication with an inner lumen 52 in hollow guidewire 42 through
apertures 54 in the wall of guidewire 42.
[0046] FIG. 8 illustrates another embodiment of a distal protection
device 60 in accordance with the present invention. Distal
protection device 60 is similar to those shown in other figures,
and similar items are similarly numbered. However, distal
protection device 60 includes hollow guidewire 63 which has a lumen
in fluid communication with an interior of a pair of inflatable
struts 62. Inflatable struts 62 have an inner surface 64 which is
generally concave, or hemispherical, or otherwise appropriately
shaped such that it extends about a portion of the outer surface of
hollow guidewire 63. Mesh portions 66 extend between the inflatable
struts 62 so that inflatable struts 62 and mesh portions 66, when
deployed outwardly as shown in FIG. 8, form a basket shape which
opens toward the proximal end of hollow guidewire 63.
[0047] FIG. 9 illustrates another system for attaching inflatable
struts to a hollow guidewire for a distal protection device 70 in
accordance with the present invention. Distal protection device 70
is similar to the distal protection devices shown in the previous
figures in that a plurality of inflatable struts 72 are provided
and preferably have a mesh portion extending therebetween. For the
sake of clarity, the mesh portion is eliminated from FIG. 9.
However, it will be understood that, when deployed, distal
protection device 70 forms a generally basket-shaped filter
assembly which opens toward the proximal end of hollow guidewire
74.
[0048] In the embodiment shown in FIG. 9, hollow guidewire 74 has a
distal end 75 which is open. An endcap 76 is disposed about the
distal end 75 of hollow guidewire 74 and defines an internal
chamber or passageway 78. Endcap 76 has a proximal end 80 which has
openings therein for receiving the ends of inflatable struts 72.
Thus, in order to inflate inflatable struts 72, the operator
pressurizes fluid within the lumen of hollow guidewire 74 forcing
fluid out through distal end 75 of hollow guidewire 74, through
passageway 78, and into inflatable struts 72. In order to collapse
distal protection device 70, the operator draws a vacuum which
pulls the fluid back out of inflatable struts 72, through
passageway 78 and, if necessary, into the lumen of hollow guidewire
74.
[0049] FIG. 10 is an end view of endcap 76 taken along lines 10-10
in FIG. 9. FIG. 10 shows that proximal end 80 of endcap 76
preferably includes a first generally central aperture 82 for
receiving the distal end of hollow guidewire 74. Aperture 82 is
sized just larger than, or approximating, the outer diameter of
hollow guidewire 74 such that it fits snugly over the distal end 75
of hollow guidewire 74. Endcap 76 is then fixedly connected to the
distal end 75 of hollow guidewire 74 through a friction fit, a
suitable adhesive, welding, brazing, or another suitable connection
technique.
[0050] FIG. 10 also shows that proximal end 80 of endcap 76
includes a plurality of apertures 84 which are spaced from one
another about end 80. Apertures 84 are sized to receive open ends
of inflatable struts 72. In the preferred embodiment, inflatable
struts 72 are secured within apertures 84 using a suitable
adhesive, or another suitable connection technique. Also, in the
preferred embodiment, spring tip 16 is embedded in, or otherwise
suitably connected to, endcap 76.
[0051] FIGS. 11A and 11B show two other preferred embodiments of a
distal protection device in accordance with the present invention.
FIG. 11A shows distal protection device 90 which includes hollow
guidewire 92 having a lumen running therethrough, inflatable member
94 and mesh portion 96. FIG. 11A shows that inflatable member 94,
when inflated, forms a ring about the outer surface of hollow
guidewire 92. The ring has an inner periphery 98 which is spaced
from the outer surface of hollow guidewire 92 substantially about
the entire radial periphery of hollow guidewire 92. Mesh portion 96
extends between the outer surface of hollow guide 92 and the inner
periphery 98 of inflatable member 94. Thus, a substantially
disc-shaped filter assembly is provided upon deployment of distal
protection device 90. As with the other embodiments, deployment of
distal protection device 90 is accomplished by providing fluid
through the inner lumen of hollow guidewire 92 into an interior of
inflatable member 94 which is in fluid communication with the inner
lumen of hollow guidewire 92.
[0052] In one preferred embodiment, end 100 of inflatable member 94
is coupled to a coupling portion 102 of inflatable member 94 such
that stability is added to inflatable member 94, when it is
inflated.
[0053] FIG. 11B illustrates another distal protection device 104
which includes a hollow guidewire 106 and an inflatable member 108.
Device 104 is similar to distal protection device 90 except that,
rather than having only a single inflatable ring upon deployment of
distal protection device 104, a plurality of generally
equal-diameter rings are formed into a helix shape. In the
preferred embodiment, distal protection device 104 includes a mesh
sleeve 110 which extends about the outer or inner surface of the
helix formed by inflatable member 108. In one embodiment, mesh
sleeve 110 is connected to the outer surface of hollow guidewire
106 in a region 112 proximate, but distal of, inflatable member
108. In another preferred embodiment, the proximal end of mesh
sleeve 110 is connected to the outer perimeter of inflatable member
108. Thus, distal protection device 104 forms a generally
basket-shaped filter assembly which opens toward a proximal end of
guidewire 106.
[0054] As with the other embodiments, both distal protection device
90 shown in FIG. 11A and distal protection device 104 shown in FIG.
11B are preferably collapsible. Therefore, when collapsed, the
distal protection devices 90 and 104 preferably have an outer
dimension which approximates the outer dimension of hollow
guidewires 92 and 106, respectively. Further, as with the other
embodiments, distal protection devices 90 and 104 can either be
biased in the deployed or collapsed positions, and deployment and
collapse can be obtained either by pulling a vacuum, or
pressurizing the fluid within the lumen of the hollow guidewires 92
and 106.
[0055] FIG. 12 illustrates the use of a distal protection device in
accordance with the present invention. For the sake of clarity, the
present description proceeds with respect to distal protection
device 10 only. Device 10 is shown filtering stenosis fragments
from the blood flowing through the lumen of vessel 12. FIG. 12 also
shows a dilatation device 120 which can be any suitable dilatation
device for dilating, cutting, fragmenting, or abrading, portions of
stenosis 26. In the preferred embodiment, device 120 is used in an
over-the-wire fashion over hollow guidewire 14. Thus, filter
assembly 18 is first advanced (using guidewire 14) distal of
stenosis 26. Then, filter assembly 18 is deployed outwardly to the
expanded position. Dilatation device 120 is then advanced over
guidewire 14 to stenosis 26 and is used to fragment or abrade
stenosis 26. The fragments are received within the basket of filter
assembly 18. Filter assembly 18 is then collapsed, and filter
assembly 18 and dilatation device 120 are removed from vessel 12.
Alternatively, dilatation device 120 can be removed first and
filter assembly 18 is then removed along with guidewire 14.
[0056] It should be noted that the stenosis removal device (or
atherectomy catheter) 120 used to fragment stenosis 26 can be
advanced over guidewire 14. Therefore, the device according to the
present invention is dual functioning in that it captures emboli
and serves as a guidewire. The present invention does not require
adding an additional device to the procedure. Instead, the present
invention simply replaces a conventional guidewire with a
multi-functional device.
[0057] FIGS. 13A-17B illustrate embodiments of various distal
protection devices wherein deployment and contraction of the distal
protection device is accomplished through a mechanical push/pull
arrangement.
[0058] FIGS. 13A and 13B illustrate a distal protection device 122.
FIG. 13A shows device 122 in an undeployed position and FIG. 13B
shows device 122 in a deployed position. Distal protection device
122 includes a slotted Nitinol tube 124 which has a lumen 126
extending therethrough. Tube 124 has a plurality of slots 128 at a
distal region thereof. The distal portion of slots 128 are covered
by mesh 130 which, in the preferred embodiment, is a flexible
microporous membrane. Device 122 also preferably includes a mandrel
132 which extends through the inner lumen 126 of tube 124 and is
attached to the distal end of tube 124. In the preferred
embodiment, mandrel 132 is attached to the distal end of tube 124
by an appropriate adhesive, brazing, welding, or another suitable
connection technique. Tube 124 also has, on its inner periphery in
a proximal region thereof, a plurality of locking protrusions 134.
Lock protrusions 134 are preferably arranged about a proximal
expandable region 136 disposed on mandrel 132.
[0059] In order to deploy device 122 into the deployed position
shown in FIG. 13B, the operator preferably first advances tube 124
distally of the lesion to be fragmented. In the preferred
embodiment, tube 124 has a size on the order of a guidewire, such
as a 0.014 inch outer diameter. Therefore, it easily advances
beyond the stenosis to be fragmented. The operator then pushes on
the proximal region of tube 124 and pulls on the proximal end of
mandrel 132. This causes two things to happen. First, this causes
the struts formed by slots 128 to expand radially outwardly, and
carry with them, microporous membrane 130. Thus, microporous
membrane 130 forms a generally basket-shaped filter assembly which
opens toward the proximal end of tube 124. In addition, proximal
expandable member 136 expands and engages protrusions 134. This
locks device 122 in the deployed and expanded position. In order to
move the device 122 to the collapsed position, the physician simply
pushes on mandrel 132 and pulls on the proximal end of tube 124.
This causes device 122 to return to the undeployed position shown
in FIG. 13A.
[0060] It should be noted that device 122 can optionally be
provided with a stainless steel proximal hypotube attachment. Also,
the struts defined by slots 128 can be expanded and retracted using
a fluid-coupling instead of a mandrel. In other words, the proximal
end of tube 124 can be coupled to a pressurizable fluid source. By
making slots 128 very thin, and pressurizing the fluid, the struts
expand outwardly. Further, by pulling vacuum on the pressurizable
fluid, the struts collapse.
[0061] FIG. 14A illustrates distal protection device 140 which is
similar to that shown in FIGS. 13A and 13B, except that the struts
142 are formed of a metal or polymer material and are completely
covered by mesh 144. Mesh 144 includes two mesh portions, 146 and
148. Mesh portion 146 is proximal of mesh portion 148 on device 140
and is a relatively loose mesh which will allow stenosis fragments
to pass therethrough. By contrast, mesh 148 is a fairly tight mesh,
or a microporous membrane, (or simply loose mesh portion 146 with a
microporous membrane or other suitable filter material bonded or
cast or otherwise disposed thereover) which does not allow the
fragments to pass therethrough and therefore captures and retains
the fragments therein. The mesh portions can provide a memory set
which, in the relaxed position, is either deployed or
collapsed.
[0062] FIG. 14B illustrates a device 150 which is similar to device
140 shown in FIG. 14A, except struts 142 are eliminated and the two
mesh portions 146' and 148' are simply joined together at a region
152. Also, the two mesh portions 146' and 148' are not two
different discrete mesh portions but are formed of the same braided
mesh material wherein the braid simply has a different pitch. The
wider pitch in region 146' provides a looser mesh, whereas the
narrower pitch in region 148' provides a tighter mesh that traps
the embolic material.
[0063] FIG. 14C illustrates a distal protection device 160 which is
similar to that shown in FIG. 14A. However, rather than simply
providing a slotted tube, distal protection device 160 includes a
plurality of struts 162 on a proximal region thereof and a
plurality of struts 164 on the distal region thereof. Struts 162
are spaced further apart than struts 164 about the periphery of
protection device 160. Therefore, struts 162 define openings 166
which are larger than the openings 168 defined by struts 164 and
allow stenosis fragments to pass therethrough. Also, struts 164
have secured to the interior surface thereof a filter or mesh
portion 170. When deployed, filter portion 170 forms a
substantially basket-shaped filter device opening toward the
proximal region of tube 172.
[0064] FIG. 15 illustrates the operation of another distal
protection device 176. Distal protection device 176 includes a tube
178 and a push/pull wire 180. Tube 178 has, at the distal end
thereof, a filter assembly 182. Filter assembly 182 includes a
plurality of preferably metal struts 184 which have a microporous
membrane, or other suitable mesh 186 disposed thereon. Tube 178
also preferably includes end cap 188 and umbrella-like expansion
structure 190 disposed at a distal region thereof. Expansion
structure 190 is connected to the distal region of tube 178 and to
metal struts 184 such that, when push/pull wire 180 is pulled
relative to tube 178, expansion member 190 exerts a radial,
outwardly directed force on struts 184 causing them to expand
radially outwardly relative to the outer surface of tube 178. This
causes microporous membrane or mesh 186 to be deployed in a manner
opening toward the proximal end of tube 178 to catch embolic
material. Struts 184 can also be formed of an appropriate polymer
material.
[0065] FIGS. 16A and 16B illustrate a protection device in
accordance with another embodiment of the present invention. FIG.
16A illustrates distal protection device 192. Device 192 includes
guidewire 194, actuator wire 196, and filter assembly 198. Filter
assembly 198 includes an expandable ring 200, such as an expandable
polymer or metal or other elastic material, which has attached
thereto mesh 202. Mesh 202 is also attached to guidewire 194
distally of ring 200. Actuator wire 196 is attached to sleeve or
sheath 204 which is positioned to fit about the outer periphery of
expandable ring 200, when expandable ring 200 is in the collapsed
position.
[0066] Thus, when sheath 204 is moved distally of expandable ring
200, expandable ring 200 has shape memory which causes it to expand
into the position shown in FIG. 16A. Alternatively, when sheath 204
is pulled proximally by pulling actuator wire 196 relative to
guidewire 194, sheath 204 collapses ring 200 and holds ring 200 in
the collapsed position within sheath 204. Manipulating wires 194
and 196 relative to one another causes device 192 to move from the
deployed position to the collapsed position, and vice versa.
[0067] FIG. 16B is similar to device 192 except that, instead of
having an expandable ring 200 connected at one point to wire 194,
distal protection device 206 includes expandable member 208 which
is formed of an elastic coil section of wire 194. Thus, elastic
coil section 208 has a shape memory which causes it to expand into
the generally helical, conical shape shown in FIG. 16B. However,
when sheath 204 is pulled proximally relative to expandable member
208, this causes sheath 204 to capture and retain expandable member
208 in a collapsed position. When sheath 204 is again moved
distally of expandable member 208, expandable member 208 returns to
its expanded position shown in FIG. 163 carrying with it mesh 210
into a deployed position. In the preferred embodiment, sheath 204
is formed of a suitable polymer material and expandable member 208
and expandable ring 200 are preferably formed of Nitinol.
[0068] FIGS. 17A and 17B illustrate the operation of another distal
protection device 212. Protection device 212 includes guidewire 214
and filter assembly 216. In the preferred embodiment, filter
assembly 216 includes a wire braid portion 218 which extends from a
distal region of guidewire 214 proximally thereof. Braid portion
218 is formed of braided filaments or fibers which have a shape
memory causing them to form a deployed, basket-shaped filter, such
as that shown in FIG. 17A, in the unbiased position. Braided
portion 218 terminates at its proximal end in a plurality of
eyelets 220. One or more cinch wires 222 are preferably threaded
through eyelets 220. By pushing on guidewire 214 and pulling on
cinch wires 222, the operator is able to cinch closed, and pull
proximally, the proximal portion of mesh 218. This causes mesh 218
to collapse tightly about the outer surface of wire 214.
[0069] Therefore, during operation, the operator holds mesh 218 in
the collapsed position and inserts protection device 212 distally
of the desired stenosis. The operator then allows cinch wire 222 to
move distally relative to guidewire 214. This allows mesh 218 to
open to the deployed position shown in FIG. 17A which has an outer
diameter that approximates the inner diameter of the lumen within
which it is disposed. Filter assembly 216 is then disposed to
capture embolic material from blood flowing therethrough. Once the
embolic material is captured, the operator again moves cinch wire
222 proximally relative to guidewire 214 to collapse filter
assembly 216 and capture and retain the embolic material in filter
assembly 216. The device 212 is then removed.
[0070] FIG. 17B shows distal protection device 212 except that in
the embodiment shown in FIG. 17B, protection device 212 is not
disposed distally of the stenosis, but rather proximally. This
results, for example, in an application where the blood flow is
proximal of the stenosis rather than distal. Further, in the
embodiment shown in FIG. 17B, guidewire 214 is preferably hollow
and the cinch wire 222 extends through the lumen therein. By
pushing on guidewire 214, a force is exerted on mesh 218 in the
distal direction. This causes cinch wire 222 to tightly close the
distal opening in filter assembly 216 and to collapse mesh portion
218. By contrast, by allowing cinch wire 222 to move distal
relative to hollow guidewire 214, mesh portion 218 expands and
filter assembly 216 is deployed as shown in FIG. 17B.
[0071] FIGS. 18A and 18B illustrate a distal protection device 250
in accordance with another aspect of the present invention. Device
250 includes inner wire 252 and outer tube 254. In the preferred
embodiment, inner wire 252 is a core wire and outer tube 254 has a
lumen 256 therein large enough to accommodate longitudinal movement
of inner wire 252 therein. Also, in the preferred embodiment, inner
wire 252 has, coupled to its distal end 258, a spring tip 260.
[0072] Device 250 includes expandable mesh or braid portion 262.
Expandable portion 262 has a proximal end 264 which is attached to
the distal end 266 of tube 254. Also, expandable member 262 has a
distal end 268 which is attached to the distal end 258 of inner
wire 252.
[0073] Expandable member 262 is preferably a mesh or braided
material which is coated with polyurethane. In one preferred
embodiment, a distal portion of expandable member 262 has a tighter
mesh than a proximal portion thereof, or has a microporous membrane
or other suitable filtering mechanism disposed thereover. In
another preferred embodiment, expandable member 262 is simply
formed of a tighter mesh or braided material which, itself, forms
the filter. FIG. 18A illustrates device 250 in a collapsed, or
insertion position wherein the outer diameter of mesh portion 262
closely approximates the outer diameters of either inner wire 252
or outer tube 254.
[0074] FIG. 18B illustrates device 250 in the deployed position in
which expandable member 262 is radially expanded relative to the
collapsed position shown in FIG. 18A. In order to deploy device
250, the outer tube 254 is moved distally with respect to inner
wire 252 such that the distal ends 266 and 258 of wires 254 and 252
move longitudinally toward one another. Relative movement of ends
266 and 258 toward one another causes the mesh of expandable member
262 to buckle and fold radially outwardly. Thus, the outer diameter
of expandable member 262 in the deployed position shown in FIG. 18B
closely approximates the inner diameter of a vessel within which it
is deployed.
[0075] FIG. 18C illustrates device 250 in a partially collapsed
position. In FIG. 18C, the distal end 266 of outer tube 254 and the
distal end 258 of inner wire 252 are moved even closer together
than they are as shown in FIG. 18B. This causes expandable mesh
portion 262 to fold over itself and form a rolling, proximally
directed flap 270. As longitudinal movement of inner wire 252
proximally with respect to outer tube 254 continues, mesh portion
262 continues to fold over itself such that the rolling flap
portion 270 has an outer radial diameter which continues to
decrease. In other words, expandable mesh portion 262 continues to
fold over itself and to collapse over the outer periphery of outer
tube 254.
[0076] FIG. 18D illustrates device 250 in a fully collapsed
position in which it retains emboli captured therein. In FIG. 18D,
the distal end 266 of outer tube 254 has been advanced as far
distally as it can relative to the distal end 258 of inner wire
252. This causes expandable mesh portion 262 to fold all the way
over on itself such that it lies against, and closely approximates
the outer diameter of, outer tube 254. Device 250 thus captures any
emboli filtered from the vessel within which it was deployed, and
can be removed while retaining that embolic material.
[0077] FIG. 19 illustrates device 280 which depicts a further
aspect in accordance with the present invention. Device 280
includes outer tube 282, core wire 284, transition tube 286,
movable plunger 288, expandable member 290, fixed collar 292 and
bias member 294.
[0078] In the preferred embodiment, tube 282 comprises a proximal
hypotube which is coupled to a plunger that selectively provides
fluid under pressure through an inflation lumen 296. Inner wire 284
is preferably a tapered core wire which terminates at its distal
end in a spring coil tip 298 and which is coupled at its proximal
end 300 to transition tube 286. Transition tube 286 is preferably
an outer polymer sleeve either over hypotube 282, or simply
disposed by itself and coupled to a hypotube 282. Transition tube
286 is capable of withstanding the inflation pressure provided by
the fluid delivered through the inflation lumen 296.
[0079] Movable collar 288 is preferably slidably engageable with
the interior surface of transition tube 286 and with the exterior
surface of core wire 284, and is longitudinally movable relative
thereto. Slidable collar 288 has, attached at its distal end, bias
spring 294 which is preferably coiled about core wire 284 and
extends to fixed collar 292. Fixed collar 292 is is preferably
fixedly attached to the exterior surface of a distal portion of
core wire 284.
[0080] Expandable member 290 is preferably formed, at a proximal
portion thereof, of either discrete struts, or another suitable
frame (such as a loose mesh) which allows blood and embolic
material to flow therethrough. The proximal end 302 of expandable
member 290 is coupled to a distal region of movable collar 288. The
distal portion of expandable member 290 is preferably formed of a
filtering material which is suitable for allowing blood flow
therethrough, but which will capture embolic material being carried
by the blood.
[0081] In one preferred embodiment, spring 294 is biased to force
collars 288 and 292 away from one another. Thus, as spring 294
urges collars 288 and 292 away from one another, collar 288
retracts within transition tube 286 pulling expandable member 290
into a collapsed position about core wire 284. However, in order to
deploy collapsible member 290 as shown in FIG. 19, the operator
preferably actuates a plunger (not shown) which delivers
pressurized fluid through lumen 296. The pressurized fluid enters
transition tube 286 and travels about the outer periphery of inner
core wire 284, thus forcing movable collar 288 to move distally
along core wire 284. This overcomes the spring force exerted by
spring 294 thus causing collars 288 and 292 to move toward one
another, relatively. This motion causes expandable member 290 to
buckle and expand outwardly to the deployed position shown in FIG.
19.
[0082] Expandable member 290 is collapsed by releasing the pressure
applied through lumen 296 (i.e., by causing the plunger to move
proximally). This allows spring 294 to again urge collars 288 and
292 away from one another to collapse expandable member 290. In an
alternative embodiment, the frame supporting expandable member 290
is imparted with a memory (such as a heat set, or a thermally
responsive material which assumes a memory upon reaching a
transition temperature) such that the resting state of the frame
supporting expandable member 290 is in a collapsed position. This
eliminates the need for spring 294. The expandable member 290, in
that preferred embodiment, is expanded using the hydraulic pressure
provided by the pressurized fluid introduced through lumen 296, and
it is collapsed by simply allowing the memory in expandable member
290 to force fluid from transition tube 286 back through lumen
296.
[0083] FIGS. 20A and 20B illustrate another aspect in accordance
with the present invention. A device 310 includes a mesh portion
312 supported by a frame 314. Expansion of frame 314 to the
radially expanded position shown in FIG. 20A is driven by an
expandable member, such as a balloon, 316 which is coupled to frame
314. Balloon 316 is coupled to a distal end of a distal hypotube
318, which is formed of a suitable material, such as nitinol. It
should be noted that the distal tip of hypotube 318 includes a
spring tip 320.
[0084] Distal hypotube 318 is shown coupled to a proximal hypotube
322 which has a tapered portion 324 therein. In the preferred
embodiment, proximal hypotube 322 is formed of a suitable material,
such as stainless steel. A plunger 326 is longitudinally movable
within the lumen of both proximal hypotube 322 and distal hypotube
318.
[0085] Frame 314, and consequently mesh portion 312, are deployed
by the operator moving plunger 326 distally within the lumens of
hypotubes 318 and 322. This causes pressurized fluid to enter
balloon 316, thereby inflating balloon 316 and driving deployment
of frame 314 and mesh 312. In order to collapse frame 314 and mesh
312, the operator preferably moves plunger 326 proximally within
the lumens of tubes 318 and 322 to withdraw fluid from within
balloon 316. Alternatively, mesh 312 or frame 314 can have a memory
set which is either in the inflated or collapsed position such that
the operator need only affirmatively move frame 314 and mesh 312 to
either the deployed or collapsed position, whichever is opposite of
the memory set.
[0086] In either case, it is desirable that the operator be able to
lock plunger 326 in a single longitudinal position relative to
hypotubes 318 and 322. Thus, device 310 includes a locking region
328.
[0087] FIG. 20B illustrates locking region 328 in greater detail.
FIG. 20B illustrates that, in locking region 328, plunger 326 has a
plurality of grooves 330 formed in the outer radial surface
thereof. Also, in accordance with the present invention, FIG. 20B
illustrates that one of hypotubes 318 or 322 has an inwardly
projecting portion 332. In one preferred embodiment, inwardly
projecting portion 332 includes an inwardly extending, deflectable,
annular rim which extends inwardly from either hypotube 318 or 322.
In another preferred embodiment, the inwardly projecting portion
332 includes a plurality of discrete fingers which extend inwardly
from one of hypotubes 318 or 322 and which are angularly displaced
about the interior periphery of the corresponding hypotube 318 or
322.
[0088] In operation, as the operator advances plunger 326 distally
within the lumens of hypotubes 318 and 322, inwardly projecting
portion 332 rides along the exterior periphery of plunger 326 until
it encounters one of grooves 330. Then, inwardly projecting portion
332 snaps into the groove 330 to lock plunger 326 longitudinally
relative to tubes 318 and 322.
[0089] It should be noted that, in the preferred embodiment, both
inwardly projecting portions 332 and grooves 330 are formed such
that, when gentle pressure is exerted by the operator on plunger
326 relative to hypotubes 318 and 322, projection portions 332
follow the contour of grooves 330 up and out of grooves 330 so that
plunger 326 can again be freely moved within the lumens of
hypotubes 318 and 322. Thus, the relative interaction between
projecting portions 332 and grooves 330 provides a ratcheting type
of operation wherein plunger 326 can be releasably locked into one
of a plurality longitudinal positions relative hypotubes 318 and
322, since a plurality of grooves 330 are provided. Plunger 326 can
be moved back and forth longitudinally within the lumens of
hypotubes 318 and 322 in a ratcheting manner and can be locked into
one of a plurality of relative longitudinal positions because there
are a plurality of grooves 330 in the exterior of plunger 326. It
should also be noted, however, that in another preferred
embodiment, a plurality of sets of inwardly projecting portions 332
are provided along the inner longitudinal surface of hypotubes 318
and/or 322. In that case, only a single groove 330 needs to be
formed in the exterior surface of plunger 326; and the same type of
ratcheting locking operation is obtained.
[0090] In the preferred embodiment, at least the exterior of
hypotubes 318 and 322, and preferably the exterior of plunger 326,
are tapered. This allows device 310 to maintain increased
flexibility. It should also be noted that, in the preferred
embodiment, hypotubes 318 and 322 are preferably sized as
conventional guidewires.
[0091] FIG. 21A illustrates a protection device in accordance with
another embodiment of the present invention. FIG. 21A illustrates
distal protection device 340. Device 340 is similar to devices 192
and 206 shown in FIGS. 16A and 16B. However, in the preferred
embodiment, device 340 includes hoop-shaped frame 342, filter
portion 344, and wire 346. Hoop-shaped frame 342 is preferably a
self-expanding frame formed of a wire which includes a shape memory
alloy. In a more preferred embodiment hoop-shaped frame 342 is
formed of a nitinol wire having a diameter in a range of
approximately 0.002-0.004 inches.
[0092] Filter portion 344 is preferably formed of a polyurethane
material having holes therein such that blood flow can pass through
filter 344, but emboli (of a desired size) cannot pass through
filter 344 but are retained therein. In one preferred embodiment,
filter material 344 is attached to hoop-shaped frame 342 with a
suitable, commercially available adhesive. In another preferred
embodiment, filter 344 has a proximal portion thereof folded over
hoop-shaped frame 342, and the filter material is attached itself
either with adhesive, by stitching, or by another suitable
connection mechanism, in order to secure it about hoop-shaped frame
342. This connection is preferably formed by a suitable adhesive or
other suitable connection mechanism.
[0093] Also, the distal end of filter 344 is preferably attached
about the outer periphery of wire 346, proximate coil tip 348 on
wire 346.
[0094] In one preferred configuration, filter 344 is approximately
15 mm in longitudinal length, and has a diameter at its mouth
(defined by hoop-shaped frame 342) of a conventional size (such as
4.0 mm, 4.5 mm, 5 mm, 5.5 mm, or 6 mm). Of course, any other
suitable size can be used as well.
[0095] Also, in the preferred configuration, filter 344 is formed
of a polyurethane material with the holes laser drilled therein.
The holes are preferably approximately 100 .mu.m in diameter. Of
course, filter 344 can also be a microporous membrane, a wire or
polymer braid or mesh, or any other suitable configuration.
[0096] Wire 346 is preferably a conventional stainless-steel
guidewire having conventional guidewire dimensions. For instance,
in one embodiment, wire 346 is a solid core wire having an outer
diameter of approximately 0.014 inches and an overall length of up
to 300 cm. Also, in the preferred embodiment, wire 346 has a distal
end 350, in a region proximate filter 344, which tapers from an
outer diameter at its proximal end which is the same as the outer
diameter of the remainder of wire 346, to an outer diameter of
approximately 0.055 inches at its distal end. At distal region 350,
guidewire 346 is preferably formed of stainless steel 304.
[0097] Of course, other suitable guidewire dimensions and
configurations can also be used. For example guidewires having an
outer diameter of approximately 0.018 inches may also be used. For
other coronary applications, different dimensions may also be used,
such as outer diameters of approximately 0.010-inches to 0.014
inches. Further, it will be appreciated that the particular size of
wire 346 will vary with application. Applications involving neural
vasculature will require the use of a smaller guidewire, while
other applications will require the use of a larger guidewire.
Also, wire 346 can be replaced by a hollow guidewire, or hypotube
of similar, or other suitable dimensions.
[0098] In addition, in order to make wire 342, hoop 346, or filter
344 radiopaque, other materials can be used. For example,
radiopaque loaded powder can be used to form a polyurethane sheath
which is fitted over wire 346 or hoop 342, or which is implemented
in filter 344. Also, hoop 342 and wire 346 can be gold plated in
order to increase radiopacity. Also, marker bands can be used on
wire 346 or filter 344 to increase the radiopacity of the
device.
[0099] In operation, hoop 342 (and thus filter 344) is preferably
collapsed to a radially contracted position which more closely
approximates the outer diameter of wire 346. Methods of performing
this contraction are described later in the specification. Once
retracted to a more low profile position, wire 346 is manipulated
to position hoop 342 and filter 344 distal of a restriction to be
treated. Then, the restraining force which is used to restrain hoop
342 in the predeployment, low profile position is removed, and the
superelastic properties of nitinol hoop 342 (or the shape memory
properties of another shape memory alloy) are utilized in allowing
hoop 342 to assume its shape memory position. This causes hoop 342
to define a substantially lumen filling mouth to filter 344 which
is positioned distal of the restriction to be treated.
[0100] A suitable dilatation device is then advanced over wire 346
and is used to treat the vascular restriction. Emboli which are
carried by blood flow distal of the restriction are captured by
filter 344. After the dilatation procedure, filter 344, along with
the emboli retained therein, are retrieved from the vasculature.
Various retrieval procedures and devices are described later in the
specification.
[0101] By allowing hoop-shaped frame 342 to be unattached to wire
346, and only connected to wire 346 through filter 344 (or other
super structure used to support filter 344), wire 346 is allowed to
substantially float within hoop 342. This configuration provides
some advantages. For instance, hoop 342 can better follow the
vasculature without kinking or prolapsing (i.e., without collapsing
upon itself). Thus, certain positioning or repositioning of filter
344 can be accomplished with less difficulty.
[0102] FIG. 21B illustrates a protection device 352 in accordance
with another embodiment of the present invention. Protection device
352 is similar to protection device 340, and similar items are
similarly numbered. However, rather than having simply a
hoop-shaped frame 342 to support filter 344, and drive filter 344
into its expanded and deployed position, device 352 includes frame
354 which includes a hoop-shaped portion 356, and a pair of tails
358 and 360.
[0103] Tails 358 and 360 extend proximally from hoop-shaped portion
356 to an attachment region 362. In the preferred embodiment, tails
358 and 360 are attached to wire 346 at attachment region 362 by
soldering, welding, brazing, adhesive, or any other suitable
attachment mechanism. In the embodiment shown in FIG. 21B,
attachment sleeve 364, formed of a weldable material, is attached
at its inner periphery to tails 358 and 360. Sleeve 364 is then
attached, using welding or brazing, to wire 346.
[0104] By providing tails 358 and 360, frame 354 is directly
connected to wire 346. However, tails 358 and 360 are provided so
that the point of attachment of frame 354 to wire 346 is located
several millimeters proximal of hoop-shaped portion 356. This
provides some additional structural integrity to frame 354, but
still allows frame 354 to substantially float about wire 346 in the
region of hoop-shaped frame portion 356.
[0105] FIG. 21C illustrates a protection device 366 in accordance
with another embodiment of the present invention. Protection device
366 is similar to protection devices 340 and 352 shown in FIGS. 21A
and 21B, and similar items are similarly numbered. However, device
366 includes hoop-shaped frame 368. Frame 368 is similar to frame
342 shown in FIG. 21A. However, unlike frame 342, hoop 368 does not
allow wire 346 to float freely therein. Instead, hoop 368 is
directly attached to wire 346 at attachment point 370. This causes
hoop-shaped frame 368 and filter 344 to reside eccentrically about
wire 346.
[0106] FIGS. 22A-22C illustrate one preferred embodiment for
delivering one of devices 340, 352 and 366. For the sake of
clarity, only device 352 is illustrated in FIGS. 22A-22C.
[0107] FIG. 22A illustrates delivery device 372. In the preferred
embodiment, delivery device 372 includes proximal hub 374, shaft
376, and distal retaining section 378. Also, in one preferred
embodiment, device 372 also includes marker band 380. In the
preferred embodiment, delivery device 372 is similar to a
conventional balloon catheter in that proximal hub 374 is a
conventional hub, and shaft 376 is a conventional balloon catheter
shaft. Further, distal retaining section 378 is preferably a
conventional angioplasty balloon having an inflated diameter of
approximately 1.5-2.0 millimeters, but having its distal end cutoff
such that the distal end 382 of balloon 378 is open.
[0108] Prior to insertion of device 372 into the vasculature,
hoop-shaped frame 354 is retracted into its low profile deployment
position and is withdrawn through end 382 into balloon 378. Then,
the distal end of balloon 378 is exposed to heat to heat shrink or
heat set the distal end of balloon 378 around the radially
retracted device 352. Device 372, including device 352, is then
inserted in the vasculature either through a preplaced guide
catheter, along with a guide catheter, or simply without a guide
catheter utilizing coil tip 348.
[0109] In any case, once device 372 is properly placed such that
balloon 378 is located distal of the restriction to be treated,
distal protection device 352 is then removed from within heat
collapsed balloon 378. In one preferred embodiment, the physician
simply accomplishes longitudinal movement of wire 346 relative to
catheter 376. For instance, the physician may simply hold wire 346
longitudinally in place and withdraw catheter 376 proximally
relative to wire 346 by pulling on hub 374. This causes balloon 378
to move proximally relative to device 352, and thereby to expose
device 352 to the vasculature.
[0110] FIG. 22B illustrates another preferred embodiment for
removing device 352 from within balloon 378. In the embodiment
shown in FIG. 22B, syringe 384, which contains fluid, is inserted
into coupling 386 in hub 374. The physician then introduces
pressurized fluid into the lumen of catheter 376. The pressurized
fluid advances down the lumen of catheter 376 to the distal end
where it encounters collapsed balloon 378. The pressure exerted on
balloon 378 by the pressurized fluid causes balloon 378 to open
radially. Then, the physician withdraws catheter 376 relative to
device 352 thereby exposing device 352 to the vasculature.
[0111] In any case, once device 352 is no longer restrained by
balloon 378, device 352 assumes its shape memory position in the
vasculature, as illustrated in FIG. 22C. Thus, device 352
substantially forms a lumen-filling basket or filter which allows
blood to pass distally therethrough, but which retains or captures
embolic material carried by the blood flow. The physician then
simply removes device 372 from the vasculature, leaving device 352
in place during subsequent procedures. In one preferred embodiment,
shaft 376 includes a predefined slit or score from a region just
proximal of marker band 380 to, or through, hub 374. Thus, as the
physician removes device 372, it can be peeled away from device
352. Also, or alternatively, device 372 can be provided with an
aperture in shaft 376 near its distal end. The proximal end of wire
346 will thus lie outside of shaft 376. Wire 346 can enter shaft
376 through the aperture and extend through the distal end of shaft
376. This also facilitates easier withdrawal of device 372 over
wire 346.
[0112] FIGS. 23A-23E illustrate one preferred embodiment for
retrieving one of the devices 340, 352 and 366 described in FIGS.
21A-21C. For the sake of clarity, only device 352 is illustrated in
FIGS. 23A-23E. FIG. 23A illustrates retrieval device 388. Retrieval
device 388 is preferably formed of proximal shaft 390, mesh portion
392, and end cap 394. Items 390, 392 and 394 preferably each have
lumens therein to define a passageway for receiving wire 346. Also,
wire 346 may optionally be provided with an positive stop 396
(which can be embodied as a radiopaque marker band). Optional stop
396 may also simply be an annular ring attached to wire 346
proximate to filter 344, or may be any other suitable stop.
[0113] Proximal shaft 390 is preferably simply a polymer or nitinol
tube sized and configured to track over wire 346. End cap 394 is
also preferably formed to track over wire 346, but also contains
radiopaque material to serve as a distal marker band for retrieval
device 388. Mesh 392 is preferably a braid or mesh formed of wire
or polymer material having sufficient flexibility that it can be
deflected as described below.
[0114] Mesh 392 preferably has a proximal end coupled to proximal
shaft 390, by adhesive, welding, or other suitable attachment
mechanisms. Mesh 392 also preferably includes a distal end
connected to end cap 394, also by a suitable connection
mechanism.
[0115] In order to retrieve filter 344, which likely contains
embolic material, device 388 is inserted in the low profile
position shown in FIG. 23A, over wire 346, to a position proximate
filter 344. Then, device 388 is advanced toward filter 344, until
end cap 394 abuts positive stop 396, or the hoop-shaped frame 354.
Continued advancement of proximal shaft 390 relative to wire 346
causes compression of mesh 392. This results in a radial expansion
of an intermediate portion of mesh 392 (between the proximal and
distal ends of mesh 392). The radial expansion of mesh portion 392
is illustrated in FIG. 23B.
[0116] By continuing to advance proximal shaft 390 relative to wire
346, the intermediate portion of mesh 392 is configured to bend
over on itself such that it is axially displaced toward filter 344,
in the direction generally indicated by arrows 398 in FIG. 23C. In
the preferred embodiment, mesh 392 is sized and configured such
that, with continued advancement of proximal shaft 390 relative to
wire 346, this action continues as shown in FIGS. 23D and 23E until
the intermediate portion of mesh 392 encompasses at least the mouth
of filter 344. Also, in the preferred embodiment, the intermediate
portion of mesh 392, when driven as described above, engages and
contracts the mouth of filter 344 to a lower profile position, such
as that shown in FIG. 23E. In yet another preferred embodiment,
mesh 392 is sized and configured to substantially engulf the entire
filter 344.
[0117] Once at least the mouth of filter 344 is encompassed by mesh
392, device 388, along with device 352, are simply withdrawn from
the vasculature. In one preferred embodiment in which a guide
catheter is used, devices 388 and 352 are simply withdrawn either
into the guide catheter and the guide catheter is removed with
those devices, simultaneously, or devices 388 and 352 are removed
from the guide catheter prior to removal of the guide catheter. In
another preferred embodiment, in which no guide catheter is used,
devices 388 and 352 are simply removed from the vasculature
simultaneously.
[0118] It will also be appreciated, of course, that rather than
providing device 388 with a single proximal tube 390 and end cap
394, a second actuation tube or wire can also be provided which is
attached to end cap 394, and which extends back through the lumen
in proximal tube 390 and is longitudinally movable relative to
proximal shaft 390. In that way, the actuation wire or elongate
member can be used to pull cap 394 closer to the distal portion of
proximal shaft 390 in order to accomplish the action illustrated in
FIGS. 23A-23E. This feature is also illustrated in FIGS. 18A-18D
which illustrate the mesh portion folded proximally rather than
distally.
[0119] FIGS. 24A-24C illustrate another preferred embodiment in
accordance with the present invention, for retrieving any of the
distal protection devices 340, 352 or 366 shown in FIGS. 21A-21C.
For the sake of clarity, only device 352 is illustrated in FIGS.
24A-24C.
[0120] FIG. 24A illustrates retrieval device 400. Retrieval device
400 preferably includes retrieval sheath 402, proximal locking
device 404, dilator sheath 405, and nose cone 406. In the preferred
embodiment, retrieval sheath 402 is preferably formed of polyether
block amide (PEBAX) material having an outer diameter of
approximately six French (i.e., approximately 2 mm) and having a
shore D hardness of approximately 40. Also, retrieval sheath 402
preferably has a wall thickness of approximately 0.004 inches.
Dilator sheath 405, and nose cone 406, are preferably formed of low
density polyethylene, or high density polyethylene. Sheath 405
preferably has an outer diameter which is approximately equal to
the inner diameter of sheath 402. In addition, the inner diameter
of sheath 405 and nose cone 406 is preferably just large enough to
fit over, and track over, wire 346. Nose cone 406 preferably has a
proximal portion which is either attached to, or formed integrally
with, sheath 405. The outer diameter of the proximal portion of
nose cone 406 is also approximately the same as the outer diameter
of sheath 405. However, nose cone 406 also preferably has a distal
portion which tapers, or reduces along preferably a smooth curve,
to an outer diameter which terminates at the inner diameter of nose
cone 406.
[0121] Proximal locking device 404 is preferably any suitable, and
commercially available, locking device which can be configured to
lock dilator sheath 405 to guidewire 346.
[0122] In order to retrieve device 352 from the vasculature, device
400 is preferably advanced over guidewire 346 to a position shown
in FIG. 24B, in which the distal portion of nose cone 406 is
closely proximate, or adjacent to, either optional stop 396 or the
mouth of filter 344. Then, proximal locking device 404 is actuated
to lock dilator sheath 405 to wire 346 so that wire 346 and dilator
sheath 405 (as well as nose cone 406) can be moved as a unitary
piece.
[0123] Next, wire 346 (and hence dilator sheath 405 and nose cone
406) are withdrawn longitudinally relative to retrieval sheath 402.
This causes the mouth of filter 344 to enter within the distal
opening in retrieval sheath 402. This results in device 352 being
positioned relative to sheath 402 as shown in FIG. 24C. Of course,
wire 346, dilator sheath 405 and nose cone 406 can be withdrawn
further into sheath 402 such that the entire filter 344, and wire
tip 348, are disposed within the lumen of sheath 402.
[0124] In any case, once at least the mouth of filter 344 is within
sheath 402, device 352 is configured to be removed from the
vasculature. This can be accomplished by either removing dilator
sheath 405, nose cone 406 and device 352 as a unitary piece,
leaving sheath 402 in place for later removal, or by removing
sheath 402 with the remainder of the system, either through a guide
catheter or simply through the vasculature, simultaneously. Also,
where a guide catheter is used, device 352 and device 400 can be
removed through the guide catheter leaving the guide catheter in
place, or the guide catheter can be removed simultaneously with the
other devices 352 and 400.
[0125] It should be noted that all of the devices according to the
present invention can optionally be coated with an antithrombotic
material, such as heparin (commercially available under the
tradename Duraflow from Baxter), to inhibit clotting.
[0126] Thus, in accordance with one preferred embodiment of the
present invention, the superelastic properties of nitinol are used
to form a frame at least in the area of the mouth of the distal
protection filter. Thus, the distal protection device can be
deployed, retrieved, and re-deployed any number of times without
incurring plastic deformation. In addition, in other preferred
embodiments in accordance with the present invention, various
deployment and retrieval techniques and systems are provided which
address various problems associated with such systems.
[0127] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize that changes may be made in form and detail without
departing from the spirit and scope of the invention.
* * * * *