U.S. patent application number 10/001396 was filed with the patent office on 2003-04-24 for vascular embolic filter devices and methods of use therefor.
Invention is credited to Demond, Jackson, Khosravi, Fred, Krolik, Jeff, Salahieh, Amr.
Application Number | 20030078614 10/001396 |
Document ID | / |
Family ID | 21695824 |
Filed Date | 2003-04-24 |
United States Patent
Application |
20030078614 |
Kind Code |
A1 |
Salahieh, Amr ; et
al. |
April 24, 2003 |
Vascular embolic filter devices and methods of use therefor
Abstract
Vascular embolic filtering devices and systems, as well as
methods for using the same, are provided. The embolic filtering
device includes a guide wire and an associated embolic filter for
capturing emboli created during interventional procedures within a
target vessel. Features of the subject devices and system provide
for delivering of the guide wire independently of the filter,
rotating of the guide wire with respect to the filter and limiting
or preventing the proximal translation of the filter with respect
to the guide wire. The embolic filter is attached to a sheath
having either a shorter-length configuration or an extended-length
configuration. The guide wire comprises a proximal stop mechanism
engageable with the sheath to limit at least the proximal
translation of the embolic filter. The subject embolic filter
systems provide such guide wires and embolic filters, as well as
and an embolic filter delivery, deployment and removal assembly.
The methods of the present invention provide for the use of the
subject devices and systems.
Inventors: |
Salahieh, Amr; (Saratoga,
CA) ; Khosravi, Fred; (San Mateo, CA) ;
Demond, Jackson; (San Cruz, CA) ; Krolik, Jeff;
(Campbell, CA) |
Correspondence
Address: |
CROMPTON, SEAGER & TUFTE, LLC
Suite 895
331 Second Avenue South
Minneapolis
MN
55401-2246
US
|
Family ID: |
21695824 |
Appl. No.: |
10/001396 |
Filed: |
October 18, 2001 |
Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61F 2002/015 20130101;
A61F 2230/0008 20130101; A61F 2230/008 20130101; A61F 2002/018
20130101; A61F 2/01 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 029/00 |
Claims
What is claimed:
1. An intravascular embolic protection system comprising: a guide
wire; an embolic filter engageable over the guide wire, wherein the
guide wire is deliverable within a vessel independently of the
embolic filter; and a means for limiting translation of the embolic
filter over the guide wire, the means for limiting comprising a
first stop mechanism located proximal to the embolic filter when
the embolic filter is operatively engaged over the guide wire.
2. The system of claim 1 wherein the first stop mechanism limits
the proximal translation of the embolic filter along the guide
wire.
3. The system of claim 2 wherein the first stop mechanism limits
the distal translation of the embolic filter along the guide
wire.
4. The system of claim 2 wherein the first stop mechanism is
located at a distal portion of the guide wire.
5. The system of claim 4 wherein the first stop mechanism comprises
a one-way translation member wherein the sheath is able to
translate along the guide wire from a location proximal to the
proximal stop mechanism to a location distal of the proximal stop
and wherein the sheath is unable to then translate from the distal
location to the proximal location.
6. The system of claim 5 wherein the one-way translation member is
deformable.
7. The system of claim 6 wherein the one-way translation member
comprises a preformed configuration that is deformable to a low
profile configuration and deformable to a high profile
configuration.
8. The system of claim 7 wherein the low profile configuration is
formed when the sheath is translated over the first stop mechanism
in the distal direction.
9. The system of claim 7 wherein the high profile configuration is
formed when the filter is translated towards the first stop
mechanism in the proximal direction.
10. The system of claim 7 wherein the one-way translation member is
comprised of Nitinol.
11. The system of claim 7 wherein the one-way translation member
comprises at least one wire strand.
12. The system of claim 7 wherein the one-way translation member
comprises a coil having a distally increasing diameter.
13. The system of claim 5, wherein the one way translation member
includes a male threaded feature.
14. The system of claim 5 wherein the one-way translation member
has a substantially fixed configuration.
15. The system of claim 14 wherein the one-way translation member
has a naturally-biased, high profile position and an unbiased, low
profile position.
16. The system of claim 15 wherein the one-way member is
spring-loaded when in the unbiased, low profile position.
17. The system of claim 16 further comprising a protective sheath
having an open proximal end, an open distal end and a lumen
extending there between wherein the protective sheath is disposable
over the one-way translation member to retain the member in a
low-profile position.
18. The system of claim 16 wherein the one-way translation member
comprises a lever.
19. The system of claim 3 wherein the first stop mechanism is
located at a proximal portion of the guide wire.
20. The system of claim 19 wherein the first stop mechanism
comprises a means for locking the axial position of the sheath with
respect to the guide wire.
21. The system of claim 20 wherein the means for locking comprises
a sleeve positionable over the guide wire.
22. The system of claim 21 wherein the sleeve has a distally
increasing diameter.
23. The system of claim 21 wherein the sleeve has a threaded
lumen.
24. The system of claim 23 wherein the guide wire has a threaded
portion that is engageable with the threaded lumen.
25. The system of claim 1 wherein the means for limiting further
comprises a second stop mechanism located proximal to the embolic
filter when the embolic filter is operatively engaged over the
guide wire.
26. The system of claim 25 wherein the second stop mechanism
comprises an enlargement member.
27. The system of claim 8 wherein the enlargement member is a
solder bead.
28. An intravascular embolic protection system for collecting and
removing debris from within a vessel, comprising: a filter attached
to a sheath comprising an open distal end, an open proximal end and
a guide wire lumen there between; a guide wire operatively disposed
with the guide wire lumen wherein the guide wire is rotatable with
respect to the filter and the filter is translatable along the axis
of the guide wire, the guide wire comprising a stop mechanism
wherein the lumen is not translatable in the proximal direction
beyond the stop mechanism.
29. The system of claim 28 wherein the sheath has a length that
extends over no more than a distal portion of the guide wire when
the filter is operatively positioned at the distal portion of the
guide wire.
30. The device of claim 29 wherein the stop mechanism is located
proximal to the sheath at the distal portion of the guide wire.
31. The system of claim 30 wherein the stop mechanism comprises a
low profile configuration and a high profile configuration.
32. The system of claim 31 wherein the stop mechanism is disposable
within the lumen of the sheath when in the low profile
configuration.
33. The system of claim 31 wherein the sheath cannot translate over
the stop mechanism in the proximal direction when the stop
mechanism is in a high profile configuration.
34. The system of claim 28 wherein the sheath has a length that
extends over substantially the length of the guide wire the sheath,
when the filter is operatively engaged over the distal portion of
the guide wire.
35. The system of claim 34 wherein the stop mechanism is located at
a proximal portion of the guide wire.
36. The system of claim 35 wherein the stop mechanism comprises
means for locking the translational position of the sheath with
respect to the guide wire wherein the filter is not translatable in
either the proximal or distal directions when the sheath is
locked.
37. The system of claim 36 wherein the sheath has a tapered distal
end portion.
38. A method of translating an embolic filter disposed over a
distal portion of a guide wire operatively positioned within a
target location within a target vessel, comprising the steps of:
providing a first stop mechanism associated with the guide wire at
a location proximal to the distally disposed embolic filter;
translating the embolic filter along the guide wire in the proximal
direction; and limiting further proximal translation of the embolic
filter by means of the first stop mechanism.
39. The method of claim 38 wherein the first stop mechanism is
located at the distal portion of the guide wire.
40. The method of claim 39 wherein the step of limiting comprises
the step of forming a barrier substantially normal to the
longitudinal axis of the guide wire.
41. The method of 38 wherein the first stop mechanism is located at
a proximal portion of the guide wire.
42. The method of 41 wherein the step of limiting comprises the
step of locking the position of the filter with respect to the
guide wire.
43. The method of 42 wherein the step of locking comprises the step
of preventing the axial translation of the filter along the guide
wire.
44. A method for delivering an embolic filter to within a target
vessel comprising the steps of: providing a guide wire having a
first stop mechanism; and delivering a distal portion of the guide
wire to a target location within the target vessel; and translating
the embolic filter along the guide wire in the distal direction to
a location distal of the first stop mechanism.
45. The method of claim 44 wherein the step of translating
comprises the step of decreasing the profile of the proximal stop
mechanism.
46. The method of claim 45 wherein the proximal stop mechanism has
a dimension substantially normal to the longitudinal axis of the
guide wire and wherein the step of decreasing the profile of the
first stop mechanism comprises the step of reducing the
dimension.
47. The method of claim 46 wherein the first stop mechanism
comprises a wire component and the step of decreasing the profile
of the first stop mechanism comprises the step of elongating or
stretching the wire component.
48. The method of claim 45 wherein the first stop mechanism
comprises a lever and the step of decreasing the profile of the
first stop mechanism comprises the step of lowering the lever to a
position substantially parallel with the guide wire.
49. The method of claim 44 further comprising the steps of:
translating the embolic filter along the guide wire in the proximal
direction; and by means of the first stop mechanism, preventing the
embolic filter from translating further in the proximal
direction.
50. The method of claim 49 wherein the step of preventing the
embolic filter from further proximal translation comprises the step
of increasing the profile of the first stop mechanism.
51. The method of claim 50 wherein the first stop mechanism has a
dimension substantially normal to the longitudinal axis of the
guide wire and wherein the step of increasing the profile comprises
the step of increasing the dimension.
52. The method of claim 51 wherein the first stop mechanism
comprises a wire component and the step of increasing the profile
comprises the step of compressing wire component along the
longitudinal axis of the guide wire.
53. The method of claim 51 wherein the first stop mechanism
comprises a lever and the step of increasing the profile comprises
the step of biasing the lever to a position at an angle with the
guide wire.
54. The method of claim 44 further comprising the step of fixing
the position of the filter with respect to the guide wire by means
of the first stop mechanism.
55. The method of claim 12 wherein the step of fixing the position
of the filter comprises the step of locking a proximally extending
sheath attached to the filter to a proximal portion of the guide
wire.
56. The method of 44 further comprising the step of preventing
further distal translation of the filter by means of a second stop
mechanism associated with the guide wire.
57. A method of delivery, deploying and retrieving an embolic
filter within a target vessel used to collect emboli within blood
flowing through a target site of an interventional procedure, the
method comprising the steps of: providing a guide wire assembly
comprising a guide wire and a first stop positioned at a distal
portion of the guide wire, wherein the first stop has a deployed
configuration and an undeployed configuration; delivering the
distal end of the guide wire assembly, wherein first stop is in an
undeployed configuration, to a location wherein the first stop is
distal to the target site; providing an undeployed filter attached
to a sheath; advancing the sheath over the guide wire to a location
distal of the first stop; deploying the filter; and deploying the
first stop.
58. The method of claim 57 further wherein the steps of delivering,
advancing and deploying are facilitated by fluoroscopic
imaging.
59. The method of claim 57 wherein the step of deploying the first
stop comprises the step of forming a barrier cross-wise to the
guide wire.
60. The method of claim 57 further comprising the step of
delivering one or more interventional devices to the target site
and performing one or more interventional procedures at the target
site.
61. The method of claim 57 further comprising the step of
collecting emboli and/or thrombi released from the target site.
62. The method of claim 61 further comprising the step of
retrieving the filter from the vessel.
63. The method of claim 62 wherein the step of retrieving the
filter comprises the steps of: undeploying the first stop;
undeploying the filter; and translating the undeployed filter in
the proximal direction over the undeployed first stop.
64. A method of delivery, deploying and retrieving an embolic
filter within a target vessel used to collect emboli within blood
flowing through a target site of an interventional procedure, the
method comprising the steps of: providing a guide wire assembly
comprising a guide wire and a first stop positioned at a proximal
portion of the guide wire; delivering the distal end of the guide
wire assembly to a location distal to the target site; providing an
undeployed filter attached to a sheath; advancing the sheath over
the guide wire to a distal portion of the guide wire; deploying the
filter; and fixing the position of the filter with respect to the
guide wire.
65. The method of claim 64 wherein the step of fixing the position
of the filter comprises the step of locking the sheath to the guide
wire.
66. The method of claim 65 wherein the step of locking the sheath
comprises the step of disposing a sleeve about the proximal end of
the sheath and the proximal portion of the guide wire.
67. The method of claim 66 further comprising the step of firmly
retaining the proximal end of the sheath within the sleeve.
68. The method of claim 66 further comprising the step of threading
the sleeve to the guide wire.
69. A method of deploying an intravascular device, the method
comprising the steps of: inserting a guide wire into a vessel and
maneuvering the guide wire to deliver a distal end portion of the
guide wire to a target location in a vessel; passing the
intravascular device over the guide wire, whereby the intravascular
device is freely rotatable and translatable with respect to the
guide wire; passing the intravascular device over a proximal stop
on the guide wire to a deployment position on the distal end
portion of the guide wire, the deployment position being located
between the proximal stop and a distal stop on the guide wire; and
preventing the intravascular device from translating proximally
beyond the proximal stop and distally beyond the distal stop.
70. The method of claim 69, wherein the intravascular device is a
filter, the filter being passed over the guide wire in an
undeployed condition and being expanded to a deployed condition
upon reaching the deployment position.
71. A proximal stop mechanism for use with a guide wire deliverable
in a vessel, comprising: a one-way translation member affixed to
the guide wire, wherein a device translatably disposed on the guide
wire is allowed to translate proximally over the one-way
translation member but is prevented from translating distally over
the one-way translation member.
72. The proximal stop mechanism of claim 71 further comprising
means for affixing the one-way translation member to the guide
wire.
73. The proximal stop mechanism of claim 72 wherein the means for
affixing comprises a solder bead.
74. The proximal stop mechanism of claim 72 wherein the means for
affixing comprises a spring-loadable hinge.
75. The proximal stop mechanism of claim 71 wherein the one-way
translation member comprises a low profile configuration and a high
profile configuration.
76. The proximal stop mechanism of claim 75 wherein the low profile
configuration is useful for moving the mechanism through a lesion
within a vessel.
77. The proximal stop mechanism of claim 75 wherein the high
profile configuration is useful for preventing the device from
translating proximally past the mechanism.
78. A locking mechanism for use with a guide wire deliverable in a
vessel, comprising: a sleeve member disposed over a distal portion
of the guide wire, wherein the sleeve member has means for
releasably locking the translational position of a device
translatably disposed on the guide wire.
79. The locking mechanism of claim 78 wherein the sleeve member is
made of a flexible material.
80. The locking mechanism of claim 78 wherein the sleeve member is
threaded.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to devices and methods for
filtering and removing matter from within the vasculature. More
particularly, the invention is directed to a low-profile,
self-expanding intravascular device useful for capturing emboli
generated during interventional procedures, and for thrombectomy
and embolectomy procedures.
BACKGROUND OF THE INVENTION
[0002] Vascular procedures to treat occlusive vascular diseases,
such as angioplasty, atherectomy and stent placement, often cause
blood clots to form and/or material to dislodge from inside the
vessel walls and enter the bloodstream. The dislodged material
(e.g., plaque), known as emboli, may be large enough to occlude
smaller downstream vessels, potentially blocking blood flow to
tissue. Additionally, the blood clots, known as thrombi, may be
large enough or grow over time to form a blockage at the
interventional site or at another downstream location should the
thrombus become released into the bloodstream. The resulting
ischemia may pose a serious threat to the health or life of a
patient if the blockage occurs in critical tissue, such as the
heart, brain and lungs. Such blockages can lead to myocardial
infarction and stroke.
[0003] Numerous previously known interventional systems and methods
that employ an emboli filter mechanism have been proposed to reduce
the risk of embolism. One such system includes an embolic filter
system having a radially expandable mesh filter disposed on and
fixed to the distal end of a guide wire. The filter is deployed
distal to a region of stenosis, and an interventional device, such
as an angioplasty balloon or a stent delivery system, is advanced
along the guide wire. The filter is designed to capture emboli
generated during treatment of the stenosis while permitting blood
to flow through the filter.
[0004] Another similarly-functioning embolic protection device
includes a guide wire and a filter comprised of a plurality of
struts fixed to the distal end of the guide wire by means of the
guide wire coil tip. The coil is wound about the periphery of the
distal portion of the struts to fix the struts to the guide wire,
forming a hinge-type connection by which the struts expand and
close. A similar filter system includes a generally cone-shaped
filter made of a porous polymer material. The distal end of the
filter is securely fixed or formed to the system's guidewire.
[0005] With these conventional embolic filter systems, the filter
mechanism is provided either permanently attached to or generally
disposed on the distal end of the guide wire and, thus, is
delivered simultaneously with the guide wire to the desired site
within a vessel. Coupling the filter mechanism to the distal end of
a guide wire serves to reduce the number of components in an
embolic filtration system as well as the number of steps necessary
to deliver and retrieve the components during intravascular
procedures. Furthermore, without being fixed to the guide wire or
at least restrained at the distal portion of the guide wire, a
filter is able to move along the guide wire in both distal and
proximal directions. This runs the risk of having the filter come
off the distal end of the guide wire, leaving limited options for
the safe retrieval of the filter from the patient's vasculature.
There is also the risk of an unattached filter moving too far in
the proximal direction and crossing back into the lesion, possibly
interfering with the interventional procedure being performed.
[0006] Despite the advantages of attaching the filter to the guide
wire, there are disadvantages of doing so. First and foremost, the
attached filter increases the profile of the guide wire, making the
initial crossing of the lesion more difficult particularly when the
lesion is very narrow and tight. Additionally, with the filter
fixed to the guide wire, there is a lack of independent rotational
movement of the guide wire with respect to the filter. The lack of
independent rotational movement of the guide wire increases the
likelihood that the filter sac will become entangled around the
guide wire.
[0007] It is desirable to have intravascular embolic protection
systems that provide a guide wire without a permanently attached
filter mechanism such that the guide wire may be delivered within
the target vessel independently of the filter. Furthermore, it
would be advantageous to have such devices and systems that provide
for the independent rotational movement and some independent axial
translation of the guide wire with respect to the filter. In
addition, it is desirable that such devices and systems have the
capability of limiting or preventing the axial translation of the
filter with respect to the guide wire.
SUMMARY OF THE INVENTION
[0008] The present invention pertains to protection devices
deployed in a body vessel or cavity for the collection of loosened
or floating debris, such as embolic material dislodged during or
thrombi formed as a result of an intravascular procedure. The
subject invention is particularly helpful to protect the
vasculature of a patient from dislodged emboli during angioplasty,
atherectomy, thrombectomy, embolectomy, intravascular diagnostic
and stent placement procedures.
[0009] Vascular embolic filtering systems and devices, as well as
methods for using the same, are provided. In general, the subject
systems include an independently deliverable guide wire and an
associated embolic filter mechanism independently deliverable and
retrievable over the guide wire. As such, a method of the subject
invention provides for delivering a guide wire to a target location
within a vessel distal to a lesion with the vessel and then
delivering or tracking the filter mechanism over the delivered
guide wire to a desired location at or adjacent the distal end of
the guide wire.
[0010] Other features of the subject guide wires and filter
mechanisms provide for the independent rotational movement of the
guide wire with respect to the filter. The ability and flexibility
to independently maneuver the guide wire and the filter facilitate
the adjustment and optimal positioning of each. Furthermore, one
can better ensure that the filter deploys properly and has a proper
sealing engagement with the internal vessel wall throughout the
procedure so as to reduce uncollected emboli.
[0011] The means for enabling axial translation and for
independently rotating the guide wire with respect to the filter
includes a sheath, preferably having a tubular configuration, to
which the filter is attached. When operatively associated with the
guide wire, this tubular sheath may be rotatably disposed about and
along the guide wire. In other words, the guide wire is operatively
disposed within a lumen of the tubular sheath. As such, when the
filter is deployed within a vessel, and therefore substantially
stationary at that location by the vessel wall pressure against the
filter, it is relatively unaffected by axial translation of the
guide wire. This independence of axial translation movement is
particularly useful to prevent movement of the filter against the
artery wall which causes trauma and damages the inner lining of
artery.
[0012] In certain embodiments, the tubular sheath has a relatively
short length that extends over no more than a portion of the distal
end of the guide wire when the filter is operatively position. In
other embodiments, the tubular sheath has a relatively long length
such that, when the filter is operatively positioned towards the
distal end of the guide wire, the tubular sheath extends proximally
to outside the patient's body.
[0013] The tubular sheath enables the embolic filter to translate
along the guide wire; however, the extent of translation, in both
directions, is optimally limited or prevented. The means for
limiting or preventing the axial translation of the filter includes
at least one stop mechanism associated with the guide wire. This
stop mechanism limits or prevents at least the proximal translation
of the embolic filter with respect to the guide wire. In
embodiments employing a short sheath, at least one stop mechanism
is affixed to a distal end portion of the guide wire. In
embodiments employing an extended length sheath, the proximal or
first stop mechanism, is located at a proximal portion of the guide
wire. These embodiments may further include a second or distal stop
mechanism located distally to the respective first stop mechanism
at a distal portion of the guide wire. This second or distal stop
mechanism provides a point of enlargement that prevents an embolic
filter from translating off the distal end of the guide wire. The
point of enlargement is typically a metal bead soldered to the
guide wire but may be any means for providing an enlargement over
which the embolic filter cannot pass in the distal direction. The
proximal stop includes a one-way translation member wherein the
filter is able to translate along the guide wire from a location
proximal to the proximal stop to a location distal to the proximal
stop but is unable to then translate from the distal location back
to the proximal location.
[0014] For embolic filter embodiments employing a shorter-length
sheath, the proximal stop mechanism includes a one-way translation
member affixed to the guide wire by means of a low-profile
attachment point, for example, a solder bead, hinge or shrink
tubing. The one-way translation member is configured to have a
low-profile configuration, state, condition or position and a
high-profile configuration state, condition or position. In the
low-profile state, a filter is translatable over the one-way
translation member and, in the high-profile state, a filter is
prevented from translating over the one-way translation member in
the proximal direction. A one-way translation member in a
low-profile state preferably has a profile that is aligned
longitudinally with the guide wire. The high-profile state
preferably has a profile that creates a cross-wise barrier along
the guide wire.
[0015] In certain embodiments, the one-way translation member has a
preformed configuration that is deformable to a low profile
configuration and to a high profile configuration. Such embodiments
may be made of a memory material such as nitinol. Deforming the
one-way translation member to a low profile condition requires
decreasing a dimension (e.g., the diameter or height) of the member
that is normal to the longitudinal axis of the guide wire so that
it becomes more flush or stream-line with the guide wire.
Decreasing this dimension may require constricting, stretching or
elongating the one-way translation member. On the other hand,
deforming the member to a high profile condition may require
increasing this dimension which may involve compressing the one-way
translation member so as to create a barrier substantially normal
to the longitudinal axis of the guide wire.
[0016] In other embodiments, the one-way translation member may be
formed or made of a substantially fixed structure attached to the
guide wire in a position or juxtaposition by a means, e.g., a
spring-loaded hinge, that allows it to be reduced to a low-profile
state. With either type of one-way translation member, the proximal
stop is reducible to a low-profile state by an interventional
device (e.g., a filter) disposed about the guide wire when moved
from a position proximal of the proximal stop to a position distal
of the proximal stop.
[0017] In the embodiments employing an extended-length tubular
sheath, the means for limiting or preventing the axial translation
of the filter includes a proximal stop mechanism preferably located
at a proximal portion of the guide wire that extends outside the
patient's body when the guide wire is operatively placed within the
target vessel. The proximal stop mechanism includes means for
locking the position of the sheath to which the filter is attached.
When the position of the sheath is locked into place, the embolic
filter is prevented from translating both proximally and distally
and, thus, fixes the axial position of the embolic filter with
respect to the guide wire. The means for locking the sheath
includes a sleeve or the like placed circumferentially about the
proximal end of the sheath and the guide wire, thereby holding the
proximal portion of the sheath between the sleeve and the guide
wire. The means for limiting or preventing may further include a
second or distal stop mechanism similar to the one mentioned
above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 includes FIGS. 1A-F which illustrate an one
embodiment of an intravascular embolic filter system of the subject
invention operatively employed, and a method for using the devices
and systems of the present invention; wherein:
[0019] FIG. 1A illustrates one embodiment of a guide wire assembly
of the present invention having a guide wire and an axial movement
limitation system for limiting the axial movement of a filter
operatively engaged with the guide wire, the axial movement
limitation system including a proximal stop mechanism and a distal
stop mechanism, the proximal stop mechanism having
distally-extending wire strands shown in a preformed state;
[0020] FIG. 1B illustrates the guide wire assembly of FIG. 1A and
an embolic filter delivery, deployment and removal assembly
operatively disposed about the guide wire wherein the delivery,
deployment and removal assembly includes an embolic filter assembly
having means for rotational movement about the guide wire; the
filter assembly is being delivered over the guide wire in a distal
direction, crossing over the proximal stop mechanism and
compressing it into a low-profile state;
[0021] FIG. 1C illustrates the same guide wire assembly and embolic
filter delivery, deployment and removal assembly operatively
engaged as in FIG. 1B wherein the delivery, deployment and removal
assembly has been further advanced in a distal direction such that
the distal tip of the embolic filter assembly abuts the distal stop
mechanism;
[0022] FIG. 1D illustrates the same operative engagement wherein a
delivery sheath of the embolic filter delivery, deployment and
removal assembly is being pulled proximally away from the remainder
of the assembly such that the embolic filter has been operatively
deployed and a rotatable filter attachment tube abuts the distal
stop which prevents further advancement of the filter assembly in
the distal direction;
[0023] FIG. 1E illustrates the distal removal of a pusher mechanism
such that the proximal stop mechanism has been operatively deployed
to a high-profile state to prevent proximal movement of the embolic
filter assembly of FIG. 1D along the guide wire past the proximal
stop mechanism;
[0024] FIG. 1F illustrates the proximal end of the embolic filter
assembly of FIG. 1D abutting the proximal stop mechanism and
thereby being prevented from further axial movement in the proximal
direction;
[0025] FIG. 1G illustrates an alternate embodiment of the proximal
stop mechanism; and
[0026] FIG. 2 includes FIGS. 2A-C which illustrate another
embodiment of an intravascular embolic filter system of the subject
invention operatively employed, and a method for using the devices
and systems of the present invention; wherein:
[0027] FIG. 2A illustrates a guide wire assembly of the present
invention having a guide wire and another embodiment of an axial
movement limitation system for limiting the axial movement of a
filter operatively engaged with the guide wire, the axial movement
limitation system having a proximal stop mechanism having a
distally-extending, coiled spring configuration shown in its
preformed state;
[0028] FIG. 2B illustrates an enlarged longitudinal cross-sectional
view of a distal portion of the guide wire assembly of FIG. 2A and
the embolic filter delivery, deployment and removal assembly of
FIG. 1 being delivered over the guide wire in a distal direction,
crossing over the proximal stop mechanism and compressing the
coiled spring into a low-profile state.
[0029] FIG. 2C illustrates the same distal portion of the guide
wire assembly of FIG. 2A and the embolic filter assembly of FIG. 1,
wherein the embolic filter assembly has been operatively placed
distal to the proximal stop and is prevented from axial movement in
the proximal direction such that the proximal tip of the embolic
filter assembly abuts the proximal stop mechanism, causing it to
expand into a high-profile state.
[0030] FIG. 3 includes FIGS. 3A-C which illustrate another
embodiment of an intravascular embolic filter system of the subject
invention operatively employed, and a method for using the devices
and systems of the present invention; wherein:
[0031] FIG. 3A illustrates a guide wire assembly of the present
invention having a guide wire and another embodiment of an axial
movement limitation system for limiting the axial movement of a
filter operatively engaged with the guide wire, the axial movement
limitation system having a proximal stop mechanism having a
retractable member, shown in a deployed state;
[0032] FIG. 3B illustrates an enlarged longitudinal cross-sectional
view of a distal portion of the embolic filter delivery, deployment
and removal assembly of FIGS. 1 and 2 disposed over the guide wire
assembly of FIG. 3A which further includes a protective sheath
operatively disposed about the guide wire and the proximal stop
mechanism such that the retractable member is in an undeployed
state;
[0033] FIG. 3C illustrates the same distal portion of the guide
wire assembly of FIG. 3B after the delivery, deployment and removal
assembly has been advanced distally so as to distally advance the
protective sheath and the embolic filter assembly distally of the
retractable member and after proximal removal of the delivery,
deployment and removal assembly sheath such that the embolic filter
and retractable member have achieved respective deployed
states.
[0034] FIG. 4 includes FIGS. 4A-D, which illustrate another
embodiment of an intravascular embolic filter system of the subject
invention operably employed, and a method for using the device in
systems of the present invention; wherein:
[0035] FIG. 4A illustrates a guide wire assembly of the present
invention having a guide wire and another embodiment of an axial
movement limitation system for limiting axial movement of a filter
operably engaged with the guide wire; the axial movement limitation
system having a proximal stop mechanism having a male thread
feature;
[0036] FIG. 4B illustrates an enlarged longitudinal cross-sectional
view of a distal portion of the embolic filter delivery, deployment
and removal assembly exposed over the guidewire assembly of FIG.
4A, including a female threaded feature disposed proximally of the
male threaded feature;
[0037] FIG. 4C illustrates an enlarged longitudinal cross-sectional
view of a distal portion of the embolic filter delivery, deployment
and removal assembly disposed over the guidewire assembly of FIG.
4A, which further includes a protective sheath including the female
threaded feature disposed distally of the male threaded feature;
and
[0038] FIG. 4D illustrates the same distal portion of the guidewire
assembly of FIG. 4C after proximal removal of the delivery,
deployment and removal assembly sheath such that the embolic filter
has achieved the deployed state.
[0039] FIG. 5 includes FIGS. 5A-C which illustrate another
embodiment of an intravascular embolic filter system of the subject
invention operatively employed, and a method for using the devices
and systems of the present invention; wherein:
[0040] FIG. 5A illustrates another embodiment of an independently
deliverable guide wire of the present invention;
[0041] FIG. 5B illustrates another embodiment of a delivery,
deployment and retrieval assembly of the present invention
operatively disposed over the guide wire of FIG. 5A; and
[0042] FIG. 5C illustrates another embodiment of an embolic filter
assembly of the present invention having an extended-length tubular
sheath operatively disposed over the guide wire of FIG. 5A.
[0043] FIG. 6 illustrates an embodiment of an axial translation
limitation or prevention system employing a proximal stop mechanism
or means for locking the axial position of the tubular sheath of
FIG. 5 with respect to the guide wire, the means or mechanism
including a snuggly-fitted sleeve.
[0044] FIG. 7 is illustrates another embodiment of an axial
translation limitation or prevention system employing a proximal
stop mechanism or means for locking the axial position of the
tubular sheath of FIG. 5 with respect to the guide wire, the means
or mechanism including a threaded sleeve.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0045] Exemplary embodiments of the present invention will now be
discussed in detail.
[0046] 1. Systems and Devices
[0047] The subject systems include a guide wire and an associated
embolic filter for capturing emboli created during interventional
procedures within a target vessel. The guide wires and embolic
filters are not permanently fixed to each other and, thus, are
independently deliverable and retrievable. They also provide for
the independent rotational movement of the guide wire with respect
to the filter and for enabling and limiting the axial translation
of the filter along the guide wire. More specifically, the subject
invention includes embolic filter assemblies comprising an embolic
filter attached to an attachment sheath that is disposable, both
rotationally and translationally, about the guide wire. Certain
embodiments of the embolic filter assemblies employ relatively
short attachment sheaths while other embodiments employ long
attachment sheaths. Embodiments employing a relatively short
attachment sheath also typically provide at least one stop
mechanism located at a distal portion of the guide wire. This at
least one stop mechanism prevents the undesired proximal
translation of a filter assembly once operatively positioned at the
distal end of the guide wire. Some embodiments employ a relatively
long attachment sheath, i.e., one that extends proximally outside
the body of the patient when operatively positioned in the
vasculature. These latter embodiments typically employ a stop
mechanism positioned towards the proximal end of the guide
wire.
[0048] A. Embodiments Employing Short Filter Attachment Sheaths and
Having a Distally-Positioned Stop Mechanism
[0049] Referring now to FIGS. 1, 2, 3, and 4 wherein like
components have like reference numbers, there are shown exemplary
guide wire assemblies and embolic filter assemblies of the present
invention employing relatively short filter attachment sheaths and
at least one distally-positioned stop mechanism.
[0050] 1. Guide Wire Assemblies
[0051] Illustrated in FIGS. 1A, 2A, 3A, and 4A guide wire assembly
10 includes a guide wire 12 having a flexible or floppy tip 16.
Floppy tip 16 preferably has a spring or coiled configuration for
facilitating the easy and efficient delivery of guide wire assembly
10 into a vascular system of a patient and across a lesion within
the vasculature (not shown). Guide wire 12 is made of materials and
has length and diameter dimensions commonly known in the art of
intravascular procedures.
[0052] Guide wire assembly 10 also includes means associated with
the guide wire to limit or prevent the axial translation of an
interventional device, the means including by at least one stop
mechanism generally located at a distal end portion 14 of guide
wire 12. The at least one stop mechanism 20, referred to as a
proximal stop mechanism, prevents an operatively placed device,
such as a filter or filter assembly, from translating proximally
beyond stop mechanism 20. Guide wire assembly 10 may also include a
distal stop mechanism 18 positioned distally of proximal stop
mechanism 20 to prevent an operatively placed filter or filter
assembly from translating distally beyond distal stop mechanism 18.
Together the two stops 18, 20 define a translation segment or
deployment region 19 of guide wire 12 there between along which an
embolic filter may be translated and deployed.
[0053] Distal stop 18 is a point of enlargement located and fixed
at the distal portion 14 of guide wire 12. This point of
enlargement may be a solder bead or other means for enlarging a
distal point of guide wire 12. Proximal stop 20 includes a one-way
translation member, referenced as 22 in FIG. 1, 60 in FIG. 2, 70A
in FIG. 3 and 20 in FIG. 4, fixed to guide wire 12 by means of
fixation point 24 at a location proximal to distal stop 18.
Fixation 24 may comprise, for example, a solder bead, similar to
that of distal stop 18 of FIGS. 1, 2 and 4 or the hinge pin of FIG.
3.
a. Deformable Proximal Stop Mechanisms
[0054] The proximal stop embodiments of FIGS. 1 and 2 have a
deformable one-way translation member. More specifically, these
respective one-way translation members have a preformed or original
configuration having a wire component that is deformable to a
constricted or low profile configuration and also to an expanded or
high profile configuration. The low profile configuration allows
continued translation of a device, such as a filter, filter
assembly, sheath, tube or other medical device, tracked over guide
wire 12 in the distal direction. The expanded, high profile
configuration is formed when a device is translated along guide
wire 12 in a proximal direction and is caused to abut against the
one-way translation member. The high profile configuration creates
a cross-wise barrier substantially normal to the longitudinal axis
of the guide wire to prevent further proximal translation of the
device.
[0055] In the embodiment of FIG. 1, one-way translation member 22
has wire strands 23 that distally extend a short distance from
attachment point 24. Although two wire strands 23 are shown,
one-way translation member 22 may have only one wire strand or any
other appropriate number of wire strands. Wire strands 23 are
preferably formed of a super-elastic material, such as a
nickel-titanium alloy ("Nitinol"). As such, wire strands 23 have a
preformed configuration, as shown in FIGS. 1A and 1E, which may
have any appropriate configuration that can be constricted within a
small diameter sheath as well as expanded to a diameter that is
large enough to create a barrier to devices moving from the distal
side of the proximal stop to the proximal side of the proximal stop
but small enough so as not to cause injury to the internal wall of
the vessel. Each wire strand 23 has a preformed "elbow"
configuration that provides a spring-like action. The preformed
configuration is constrictable to an elongated, low profile
configuration, as shown in FIGS. 1B, C and D, as well as
compressible to an expanded, high profile configuration, as in FIG.
1F. The elongated, low profile configuration is formed when a
device, such as a sheath or a tube, is translated along guide wire
strand 12 and over wire strands 23 in a distal direction.
[0056] As an alternate to stop 20 of FIG. 1A, stop 20 of FIG. 1G
could be affixed to wire 12 at attachment point 24. Stop 20 of FIG.
1G can be formed from, for example a laser cut hypo-tube. Laser
cutting can form strands 23 between proximal attachment point 24 at
a distal end 52 of strands 23. At both attachment point 24 and
distal end 52 a cylindrical portion of the laser cut hypo tube can
remain. The cylindrical portion at proximal attachment point 24 can
be soldered to the guide wire, whereas the cylindrical portion at
distal 52 can be free to slide proximally and distally on guide
wire 12. Strands 23 are preferably bent outward as shown in FIG. 1G
when in a relax state. The hypo tube can be formed from stainless
steel, nickel titanium alloy ("Nitinol") or other suitable
material.
[0057] In the embodiment of FIG. 2, one-way translation member 60
is a coiled wire attached to and extending distally from solder
bead 24. As shown in FIG. 2A, coil 60 is in a deployed or biased,
preformed state wherein coil 60 has a diameter that increases
distally to a maximum diameter at distal end 62. The maximum
diameter of coil 60 is great enough to snuggly contact the internal
vessel wall. FIG. 2B illustrates coil 60 in an undeployed or
constricted, low profile state within filter attachment tube 36
such that coil 60 is stretched until distal end 62 achieves a
diameter that allows it to pass within the lumen of filter
attachment tube 36. FIG. 2C illustrated coil 60 when in a high
profile state caused by the compressive force applied by filter
assembly 37 when proximally advanced. The high profile state
provides a cross-wise barrier to devices moving from the distal
side of coil 60 to the proximal side of coil 60.
b. Fixed Configuration Proximal Stop Mechanisms
[0058] Referring now to FIG. 3, there is illustrated another
embodiment of a proximal stop 20 including a one-way translation
member 70 pivotally attached to guide wire 12 by means of a hinge
mechanism 24. The one-way translation member has a substantially
fixed configuration in the form of a lever or pivot member 70, for
example. Member 70 may be a made of a solid piece of material, such
as stainless steel or a biocompatible plastic, or may be made of a
wire conformed to define the desired outline of member 70. Member
70 has a naturally deployed or biased, high profile state, as shown
in FIGS. 3A and C, and an undeployed or unbiased, low profile state
as shown in FIG. 3B. Hinge mechanism 24 provides a spring-bias to
lever member 70 such that lever member 70 is naturally biased in a
high profile state at an angle .alpha. with guide wire 12 and
spring-loaded when in a low profile state.
[0059] When a device, such as a filter, filter assembly, sheath,
tube or other medical device, is caused to pass over proximal stop
20 in the distal direction, lever member 70 is caused to
rotationally pivot about hinge 24 and become substantially
co-axially aligned with guide wire 12, achieving a low profile
state. As soon as the device completely passes over the distal tip
of lever member 70, lever member 70 springs back to its biased,
high profile state. As such, when the device is then translated
back in the proximal direction, the device is prevented from
further proximal translation by proximal stop 20 (see FIG. 3C).
[0060] In order to minimize the risk of trauma to the patient's
vessel and/or the dislodgment of emboli while delivering guide wire
assembly 10 of FIG. 3 to a target site within the patient's
vasculature, a protective sheath 72 is disposed about proximal stop
20 to retain lever member 70 in a low profile state. Protective
sheath 72 has an inner lumen diameter sized to allow sheath 72 to
be easily pushed over lever member 70 while being snug enough to
remain in position over lever member 70 when guide wire assembly is
being delivered to or retrieved from the vessel. Protective sheath
72 has a length that preferably extends the length of lever member
70, but may be longer or shorter, and has tapered or beveled
proximal and distal ends 74 to further facilitate the atraumatic
delivery of guide wire assembly 10.
[0061] FIG. 4 illustrates another embodiment of proximal stop 20
including a male threaded feature 21 fastened to wire 12. Male
threaded feature 21 can be formed from, for example, a wire helix
disposed on wire 12. The wire helix can be connected to wire 12 by
adhesive, solder or other suitable means. Floppy tip 16 can include
a coil acting as a distal stop.
[0062] The configurations of the proximal stop mechanisms
illustrated and described herein are intended to be exemplary and
are not intended to limit the configuration of the proximal stop
mechanism of the present invention. Any other suitable
configuration, such as a distally opening umbrella configuration,
may be employed to provide the functions as described above.
[0063] 2. Filter Delivery, Deployment and Removal Assembly
[0064] The structure of an exemplary filter delivery, deployment
and removal assembly 30 of the present invention, such as those
disclosed in co-owned U.S. Pat. Nos. 6,129,739 and 6,179,861 B1,
both entitled "Vascular Device Having One or More Articulation
Regions and Methods of Use, hereby incorporated by reference, will
now be described. An exemplary filter delivery, deployment and
removal assembly 30 includes an embolic filter assembly 37 (see
FIGS. 1D-F, 2B, 3B, and 4B-C), a pusher tube 44 and a delivery
sheath 32. Delivery sheath 32 and pusher tube 44 have length
dimensions such that their proximal ends extend from the vascular
access site when their distal ends are in the vicinity of the
lesion within the target vessel. When operatively engaged, filter
assembly 37 and the distal end of pusher tube 44 are positioned
co-axially within distal end 31 of the lumen of delivery sheath 32,
wherein filter assembly 37 is positioned distally with respect to
pusher tube 44. Pusher tube 44 is used to push or advance filter
assembly 37 distally along guide wire 12 while delivery sheath 32
is also being advanced distally along guide wire 12. In FIG. 4,
sheath 32 itself acts as the pusher.
[0065] Filter assembly 37 includes a filter 40 attached along the
length of a filter attachment tube 36 (see FIGS. 1D-F, 2B-C, 3B-C,
and 4B-D). Filter attachment tube 36 has open proximal and distal
ends and a guide wire lumen there between and, as such, is
engageable and positionable co-axially about guide wire 12. Tube 36
provides for the independent rotational and translational movement
of filter 40 with respect to guide wire 12. The rotational
capabilities of filter attachment tube 36 help to mitigate the
unintentional twisting of filter 40 about guide wire 12 which can
commonly occur upon rotational movement of guide wire 12.
Attachment tube 36 also provides for the ability of filter assembly
37 to translate axially along guide wire 12, however, this
translational movement is limited by the axial translation
limitation system (i.e., distal stop 18 and proximal stop mechanism
20) mentioned above, and discussed in further detail below.
Although filter attachment tube 36 is illustrated having a tubular
configuration, any configuration which allows guide wire 12 to
translate and rotate freely through the sheath may be used with the
present invention. Attachment tube 36 of FIG. 4 includes a female
threaded portion which can be, for example, disposed at tube 36
proximal end.
[0066] Preferably, filter attachment tube 36 is made of a flexible
material, such as a polymer, including but not limited to polyamide
or polytetraethylene, to facilitate translational movement through
curvaceous vessel anatomy. In the embodiment of FIG. 1, nose cone
34 is mounted to the distal end of filter attachment tube 36 and
extends distally beyond the distal end of delivery sheath 32 in
order to facilitate atraumatic tracking of tubular tube 36 and
filter delivery, deployment and retrieval assembly 30 through the
target vessel.
[0067] Filter 40 includes a support hoop 45 and a blood-permeable
sac 51 attached thereto and, as such, support hoop 45 forms a mouth
or proximal opening of sac 51 while sac 51 provides a closed but
permeable distal end. Support hoop 45 is attached to the proximal
end 43 of tubular tube 36 such that sac 51, in either a deployed or
compressed state, lies generally axially along tubular tube 36.
Preferably, support hoop 45 is formed of a super-elastic material,
such as Nitinol, and as such has a constrictable, preformed state.
Support hoop 45 is capable of folding or being constricted to fit
into small diameter delivery sheath 32. When filter 40 is in a
deployed state, as depicted in FIGS. 1D-F, 2C, 3C, and 4D support
hoop 45 resumes its preformed configuration, forming an open
proximal end or mouth. Support hoop 45 may have a variety of other
features, as disclosed in U.S. Pat. No. 6,129,739, which enhance
its performance.
[0068] Sac 51 is preferably constructed of a thin, flexible
biocompatible material, such as a polymer material including, for
example, polyethylene, polypropylene, polyurethane, polyester,
polyethylene tetraphlalate, nylon or polytetrafluoroethylene, or
combinations thereof. Sac 51 includes openings or pores 31 that
permit blood cells to pass through the sac substantially
unhindered, while capturing any larger emboli that may be released
during an intravascular procedure. These pore sizes will permit red
blood cells to easily pass through sac 51. Sac 51 may alternatively
comprise a woven material, such as formed from the above-mentioned
polymers, in which case the pore size of the sac may be determined
as a function of the pattern and tightness of the weave.
[0069] Delivery sheath 32 has an open distal end 31 which is
sufficiently tapered (not shown) to reduce the risk of injury to a
patient's vessel or of inadvertently becoming entangled with a
placed stent (a concern when delivery sheath 32 is used to retrieve
the filter assembly after completion of a stent placement
procedure). The inner diameter of delivery sheath 32 is
sufficiently large to allow nose cone 34 (shown in FIGS. 1B-E;
discussed in detail below) of filter attachment tube 36 of filter
assembly 37 to extend distally from the opening, but sufficiently
small to prevent the distal advancement of filter attachment tube
36 beyond the opening. Alternatively, open distal end 31 may have
an inwardly-extending lip (not shown) to form an opening having a
diameter which meets the same requirements. Delivery sheath 32 has
a relatively narrow configuration for fitting through tight and
tortuous vessel anatomy. Both filter attachment tube 36 and pusher
tube 44 have inner diameters, respectively, capable of
accommodating guide wire 12 and proximal stop 20. As mentioned
above, pusher tube 44 has a length that extends outside the
vascular access when operatively positioned at the delivery site
within the target vessel, and thus its length will depend on the
length of the particular vascular delivery path into which it is
employed.
[0070] It can be appreciated that in yet another alternate
embodiment of the invention, proximal stop 20 need not be included
on wire 12. In such a configuration, pusher tube 44 can be used to
hold filter assembly 37 at the distal end of guide wire 12 against
distal stop 18. Then sheath 32 can be withdrawn proximately to
deploy filter assembly 37 on the wire.
[0071] In yet another alternate embodiment, sheath 32 can be
tapered inwardly just proximately of filter assembly 37 to engage
proximal end 43. In this configuration, filter assembly 37 can be
delivered to distal stop 18 without pusher tube 44. Once filter
assembly 37 is positioned distally of stop 20, sheath 32 can be
withdrawn proximately to deploy filter assembly 37.
[0072] B. Embodiments Employing Extended-Length Filter Attachment
Sheaths and Having a Proximally-Positioned Stop Mechanism
[0073] Referring now to FIGS. 5, 6 and 7, wherein like components
have like reference numbers, there is shown another embolic filter
system of the present invention. In accordance with the present
invention, this embolic filter system also provides for the
independent delivery of the guide wire with respect to the embolic
filter. Additionally, other features provide for the independent
rotational movement of the guide wire with respect to the filter
and for the enablement and limitation of the axial translation of
the filter along the guide wire for the purpose of optimally
positioning or adjusting the guide wire and/or the filter during an
interventional procedure.
[0074] In FIG. 5A, there is shown a guide wire assembly 10 having a
guide wire 12, a distal stop mechanism in the form of solder bead
18, and a floppy tip 16 extending distally from solder bead 18.
Without a permanently attached filter, the profile of guide wire
assembly 10 is kept low which is advantageous when negotiating
tortuous vasculature and particularly when crossing a lesion. Guide
wire 12 is preferably made of the materials discussed above with
respect to FIG. 1.
[0075] As best illustrated in FIG. 5C, there is shown another
exemplary embolic filter assembly 80 of the present invention
operatively disposed on the distal end 14 of guide wire 12. Filter
assembly 80 includes an embolic filter 82 operatively attached to
filter attachment sheath 90. Here, filter 82 has a strut-type
configuration such as those disclosed in co-owned and co-pending
U.S. patent application Ser. No. 09/764,774, entitled "Vascular
Device for Emboli Removal Having Suspension Strut and Methods of
Use" and filed on Jan. 16, 2001, hereby incorporated by reference.
Generally, filter 82 includes a blood-permeable sac 92 affixed at
its perimeter to a self-expanding support hoop 96 mounted to a
flexible suspension strut 94 which in turn is affixed to filter
attachment sheath 90 at a point proximal to filter 82. Suspension
strut 94 permits guide wire 12 to rotate and move laterally
relative to support hoop 96 without the support hoop becoming
disengaged from the vessel wall when in a deployed state. Sac 92
and support hoop 96 are preferably made of the materials mentioned
above of with respect to sac 51 and support hoop 45, respectively.
Suspension strut 94 may be made of the same materials used for the
support hoops.
[0076] Unlike filter attachment tube 36 discussed with respect to
FIGS. 1, 2, 3, and 4 filter attachment sheath 90 has a length
which, when operatively disposed over guide wire 12, extends
proximally from nose cone 84 to outside the patient's body. Thus,
extended-length filter attachment sheath 90 is itself used, rather
than the pusher tube discussed above with respect to the
embodiments of FIGS. 1, 2 and 3, to deliver and remove filter
assembly 80, as well as to rotate and axially translate filter
assembly 80 with respect to guide wire 12.
[0077] Similar to the shorter-length filter attachment sheath,
filter attachment sheath 90 has a tubular configuration positioned
co-axially about guide wire 12 and, as such, provides for the
independent rotational movement of filter 82 with respect to guide
wire 12. The rotational capabilities of filter attachment sheath 90
help to mitigate the unintentional twisting of filter 82 about
guide wire 12 which can commonly occur upon rotational movement of
guide wire 12. As sheath 90 is not permanently attached to guide
wire 12, it also provides for the ability of filter assembly 80 to
translate axially along guide wire 12, however, this translational
movement may be limited or prevented altogether by the means for
limiting or preventing the axial translation, discussed in detail
below with respect to FIGS. 6 and 7.
[0078] FIG. 5B illustrates an embolic filter delivery, deployment
and retrieval assembly 78 operatively disposed over guide wire 12
and filter assembly 80. Assembly 78 includes a delivery sheath 86
for maintaining filter 82 in an undeployed condition while
delivering filter assembly 80 to distal end portion 14 of guide
wire 12. A nose cone 84 is mounted to the distal end of attachment
sheath 90 and has an extended lip 85 that is positionable over the
distal end 87 of delivery sheath 84 to facilitate the atraumatic
tracking of assembly 78 over guide wire 12. The components of
filter delivery, deployment and retrieval assembly 78 are
preferably made of the materials mentioned with respect to the
respective corresponding components of the embodiment of FIGS. 1,
2, 3, and 4.
[0079] Referring now to FIGS. 6 and 7, there are shown two
embodiments of the axial translation limitation or prevention
systems of the subject invention for use with the embolic filter
system of FIG. 5. FIG. 6 shows an enlarged view of proximal end 98
of extended-length attachment sheath 90. The axial translation
limitation or prevention system provides a stop mechanism 100
associated with a proximal portion of guide wire 12 and the distal
end of extended-length sheath 90 for limiting both the proximal and
the distal axial translation of sheath 90 and filter assembly 80.
Stop mechanism 100 and includes a cuff or sleeve 104 disposed about
guide wire 12 and a tapered end portion 102 of sheath 90. At its
proximal end 120, sleeve 104 fits snugly about guide wire 12 and
has a slightly increasing diameter towards its distal end 122. As
such, tapered portion 102 is slideable into distal end 122 and
firmly securable between sleeve 104 and guide wire 12, thereby
preventing any proximal and distal translation of extended-length
sheath 90 and, thus, temporarily fixing or locking the position of
filter assembly 80 with respect to guide wire 12. The limitation
and prevention system may further include a distal stop mechanism
such as that discussed above with respect to FIGS. 1-4. Attachment
sheath 90 may be unlocked and relocked throughout the procedure as
necessary for axial or rotational repositioning. Sleeve 104 is
preferably made of a flexible material including, but not limited
to, a polymer. Sleeve 104 may be permanently affixed to the
proximal portion of guide wire 12 such as by means of shrink tubing
or a compressive ring or cuff. Alternately, sleeve 104 may be
frictionally slideable or moveable along guide wire 12 so as to be
positionable as desired.
[0080] FIG. 7 is an enlarged view of a longitudinal cross-section
of an alternate embodiment of an axial translation limitation or
prevention system for use with the embolic filter system of FIG. 5.
The system includes a stop mechanism 110 located at a proximal
portion of guide wire 12 for limiting or preventing the proximal
and distal axial translation of sheath 90 and filter assembly 80.
Here, stop mechanism 110 includes a threaded portion 106 of the
proximal end of guide wire 12, having threads which are engageable
with corresponding threads on the lumen of a threaded collar or
sleeve 116. Threaded sleeve 116 is preferably made of stainless
steel or other approved material. Threaded portion 106 may extend
any suitable distance along the proximal end of guide wire 12 in
order to optimize the axial position of attachment sheath 90 with
respect to guide wire 12. When positioned over threaded portion
106, distal end 98 of extended-length attachment sheath 90 can be
locked at that location by means of threaded collar 116. As such,
embolic filter assembly 80 is prevented from translating proximally
and distally as desired, and attachment sheath 90 may be unlocked
and relocked throughout the procedure as necessary for
repositioning of embolic filter assembly 80. The limitation and
prevention system may further include a distal stop mechanism such
as that discussed above with respect to FIGS. 1-4.
[0081] II. Methods
[0082] The methods of using the subject embolic filter systems and
their associated components will now be described in the context of
an intravascular procedure, such as an angioplasty, atherectomy,
thrombectomy, stent placement or intravascular diagnostic
procedure, to treat and diagnose a lesion within a target vessel,
such as a coronary artery, a carotid artery or a bypass graft
vessel, such as a saphenous vein graft.
[0083] A. Short Tubular Filter Attachment
Sheath/Distally-Positioned Stop Mechanism
[0084] The steps to use each of the subject systems of FIGS. 1, 2
and 3 are substantially the same or similar; however,
dissimilarities in such steps will be identified in the following
discussion.
[0085] After the patient has been properly prepped and a vascular
access site has been created, such as in the femoral or carotid
arteries, guide wire assembly 10 is delivered, without an attached
filter, to a target vessel (not shown) using well-known
percutaneous delivery techniques. The one-way translation member
(i.e., 22 of FIG. 1, 60 of FIG. 2, 70 of FIG. 3) of proximal stop
20 is held in a restrained or constricted condition, such as within
the lumen of delivery sheath 32 or pusher tube 44 (not shown) or,
for the embodiment of FIG. 3, within the lumen of protective sheath
72, so as to provide a low profile when crossing the lesion,
reducing the risk of dislodgement of emboli from the lesion site.
One-way translation members 22, 60 and 70, respectively, are kept
in such a restrained or constricted condition until after proximal
stop 20 has at least crossed to the distal side of the target
lesion. Preferably, proximal stop 20 is kept in a low profile
condition until after the filter assembly 37 is positioned between
distal stop 18 and proximal stop 20, upon which the one-way
translation member may be deployed.
[0086] Once guide wire assembly 10 is operatively positioned within
the target vessel, filter delivery, deployment and retrieval
assembly 30 is advanced over guide wire 12 in the distal direction.
With respect to the embodiments of FIGS. 1 and 2, assembly 30 is
advanced through the lesion, passing over and constricting proximal
stop mechanism 20 in an elongated, constricted state as it passes
through the lumen of filter attachment tube 36 (see FIGS. 1B and
2B). Assembly 30 is further advanced until filter assembly 37
becomes completely positioned between distal stop 18 and proximal
stop mechanism 20 (see FIG. 1C; not shown in FIG. 2). At this
point, or once nose cone 34 abuts distal stop 18 (see FIG. 1D; not
shown in FIG. 2), delivery sheath 32 may be pulled in the proximal
direction (designated by arrow 46 of FIG. 1D) deploying filter 40
and leaving filter assembly 37 and pusher tube 44 stationary. As
shown in FIGS. 1B-D and 2B, the filter assembly 37 is translated
distally over guide wire 12 and is caused to pass over proximal
stop 20, causing one-way translation member 22 or 60, respectively,
to constrict and become retained within the lumen of filter
attachment tube 36. After filter assembly 37 has been pushed
completely to the distal side of proximal stop 20 by means of
pusher tube 44 and delivery sheath 32, pusher tube 44 is then
translated over proximal stop 20, causing one-way translation
member 22 or 60 to enter into the lumen of pusher tube 44,
maintaining proximal stop 20 in a low profile state as shown in
FIG. 1C, for example.
[0087] Referring now to the embodiment of FIG. 3, one-way
translation member 70 is delivered to the targeted location
disposed within protective sheath 74, being held in a low profile
state. Once the guide wire assembly 10 has been operatively
positioned at a desired location within the vessel, delivery,
deployment and removal assembly 30 is tracked over guide wire 12.
Continued distal translation of assembly 30, as indicated by arrow
76 of FIG. 3B, will push protective sheath 74 distally of proximal
stop 20 and cause proximal stop 20 to enter into the lumen of
filter assembly 37, maintaining it in a low profile state.
[0088] Referring again to each of the embodiments of FIGS. 1, 2 and
3, at this point, filter assembly 37 is caused to pass over
proximal stop 20 and be positioned between distal stop 18 and
proximal stop 20, as shown in FIG. 1C, for example. Delivery sheath
32 is then retracted in the proximal direction, as indicated, for
example, by arrow 46 of FIG. 1D, deploying filter 40.
[0089] The deployment of filter 40 involves the radial-like
expansion of support hoop 45 and its sealing engagement against the
internal vessel wall (not shown). This sealing engagement is
sufficiently secure to retain filter 40 in the same location within
the vessel, however, filter 40 may experience some distal migration
if the pores of filter sac 51 become sufficiently occluded by
emboli collected therein. If such occurs, filter assembly 37 may
have to be retrieved and exchanged for another filter assembly. The
delivery and filter deployment steps just described may be
facilitated by fluoroscopic imaging and the use of one or more
radiopaque elements located on assembly 30 such as at the distal
end of sheath 32 or on nose cone 34.
[0090] After filter 40 has been deployed, pusher tube 44 is pulled
in the proximal direction, designated by arrow 48 of FIG. 1E, for
example, and removed from the vessel, thereby releasing proximal
stop mechanism 20 from its constricted state, allowing it to return
to its preformed configuration (see FIGS. 1E and 2A) or its
original state (see FIG. 3C). As such, when guide wire 12 is moved
in the distal direction, designated by arrow 53 of FIG. 1F, for
example, while filter 40 is deployed, or when filter assembly 37 is
caused to move in the proximal direction along guide wire 12 and
abut against proximal stop mechanism 20, one-way translation member
prevents further distal progression of guide wire 12 or further
proximal progression of filter assembly 37, as the case may be.
[0091] With regard to the embodiments of FIGS. 1 and 2, the
proximally-directed compression of one-way translation member 22 or
60 causes it to transform into an expanded, high profile state, as
illustrated in FIGS. 1F and 2C, creating a barrier to further
progression. More specifically, with respect to the embodiment of
FIG. 1, when the distal progression of guide wire 12 or the
proximal progression of filter assembly 37 is such that the distal
ends 52 of wires 23 of one-way translation member 22 enter into the
proximal end 54 of the lumen of tube 36, the "elbows" 50 of
translation member 22 are caused to fold outwardly to form a
cross-wise barrier, preventing any further distal translation of
guide wire 12 or proximal translation of filter assembly 37, as
illustrated in FIG. 1F. Filter assembly 37 is otherwise free to
translate axially along guide wire 12 between distal stop 18 and
proximal stop mechanism 20. The folded configuration of wires 23
also provides resistance to the unintentional crossing of the
lesion by guide wire assembly 10 when guide wire 12 is pulled in
the proximal direction.
[0092] With the embodiment of FIG. 2, when the distal progression
of guide wire 12 or the proximal progression of filter assembly 37
is such that the biased spring force of coil 60 is overcome and
caused to become fully compressed by filter assembly 37, a radial
barrier is formed cross-wise to the longitudinal axis of guide wire
12, as shown in FIG. 2C. This barrier will prevent, under normal or
typical forces used in such interventional procedures, the
over-extension of guide wire 12 in the distal direction and the
over-translation of filter assembly 37 in the proximal
direction.
[0093] Unlike the one-way translation members of FIGS. 1 and 2, the
original, biased position of lever member 70 provides the high
profile state without any compressive force from filter assembly
37. In this original, biased position, lever member 70 will
prevent, under normal or typical forces used in such an
interventional procedure, the over-extension of guide wire 12 in
the distal direction and the over-translation of filter assembly 37
in the proximal direction.
[0094] Upon completion of the interventional procedure, delivery
sheath 32, now functioning as a filter retrieval sheath, is
positioned over guide wire 12 and reinserted into the target
vessel. Delivery sheath 32 is advanced distally until its open
distal end 31 crosses the now-opened lesion. Delivery sheath 32 may
then be further advanced over proximal stop mechanism 20, thereby
causing proximal stop mechanism 20 to enter into distal end 31 and
be positioned in its elongated state within delivery sheath 32.
Delivery sheath 32 may then be advanced over filter assembly 37,
causing support hoop 45 of filter 40 to fold and collapse, thereby
sealing the contents captured within sac 51. Continued incremental
advancement causes the entirety of filter assembly 37 to be
positioned within distal end 31 of delivery sheath 32 and distal
end 31 to abut the proximal end of nose cone 34. Alternatively,
after the open distal end 31 of delivery sheath 32 has crossed to
the distal side of the lesion, guide wire 12 and attached filter
assembly 37 may be pulled proximally to withdraw and retrieve
filter assembly 37 into the opening at distal end 31. Delivery
sheath 32 and guide wire assembly 10 are now withdrawn from the
target vessel. The vasculature access site may then be closed by
many well-known techniques in the art.
[0095] In use, the system of FIG. 4 is deployed by placing
guidewire 12 in a desired location within the patient. Sheath 30
including filter assembly 37 disposed therein is advanced distally
along wire 12 until male threaded feature 24 engages female
threaded feature 69 (FIG. 4B). Wire 12 is then rotated relative to
delivery sheath 30 and filter 37 to further threadedly engage
feature 24 with feature 69 until filter assembly 37 is disposed
distally of male threaded feature 24 (FIG. 4C). Then sheath 30 is
withdrawn proximally to allow filter 42 to expand (FIG. 4D).
[0096] B. Extended-Length Tubular Filter Attachment
Sheath/Proximally-Positioned Stop Mechanism
[0097] The steps necessary to use the subject system of FIGS. 5, 6
and 7 will now be described.
[0098] After the patient has been properly prepped and a vascular
access site has been created, such as in the femoral or carotid
arteries, guide wire assembly 10 of FIG. 5A is delivered, without
an attached filter, to within a target vessel (not shown) using
well-known percutaneous delivery techniques. Once guide wire
assembly 10 is operatively positioned within the target vessel,
filter delivery, deployment and retrieval assembly 78 is advanced
over guide wire 12 in the distal direction, crossing the lesion to
distal portion 14 of guide wire 12. Delivery sheath 86 maintains
filter 82 in an undeployed state while it is being translated to
distal portion 14, as shown in FIG. 5B. Delivery sheath 86 is then
retracted in the proximal direction thereby deploying filter 90, as
shown in FIG. 5C, at distal portion 14.
[0099] The deployment of filter 82 involves the radial-like
expansion of support hoop 96 and its subsequent sealing engagement
against the internal vessel wall (not shown). This sealing
engagement is sufficiently secure to retain filter 82 in the same
location within the vessel as desired; however, filter 90 may
experience some unintentional distal migration if the pores of
filter sac 92 become sufficiently occluded by emboli collected
therein or during catheter exchanges. If such occurs, filter
assembly 80 may have to be retrieved (to be described below
regarding the removal of filter assembly 80) and exchanged for
another filter assembly. The delivery and filter deployment steps
just described may be facilitated by fluoroscopic imaging and the
use of one or more radiopaque elements located on filter assembly
80 such as at the distal end of attachment sheath 82 or on nose
cone 85.
[0100] Once filter 82 is operatively deployed within the subject
vessel, the position of filter 82 may releasably locked or fixed
with respect to the guide wire. To fix the position, or otherwise
limit or prevent at the translation of filter 82, extended-length
attachment sheath 90 may be releasably locked to guide wire 12 by
means of a stop mechanism, such as those of FIGS. 6 and 7, located
at a proximal portion of guide wire 12. The locking process
includes disposing a sleeve, 104 or 116 of FIGS. 6 and 7,
respectively, about guide wire 12 and the proximal end of
attachment sheath 90. The sheath is made to firmly retain the
proximal end of the sheath within the sleeve. Using the proximal
stop mechanism of FIG. 6 for this purpose involves inserting at
least a portion 122 of the proximal end 98 of sheath 90 into the
distal opening of sleeve 104 that provides sufficient compression
on portion 122 to firmly hold it in place. Using the proximal stop
mechanism of FIG. 6 involves positioning a distal portion of sheath
90 over a threaded portion 114 of guide wire 12 and then threading
a threaded sleeve 116 over threaded portion 114, thereby firmly
retaining sheath 90 between guide wire 12 and sleeve 116.
Alternately, attachment sheath 90 may be manually held at its
proximal end in order to fix the position of the embolic filter.
Sheath 90 may be unlocked as desired to reposition or remove the
embolic filter.
[0101] The interventional procedure(s) may then be performed by
interventional instruments, such as angioplasty catheters,
atherectomy devices, stent delivery systems or intravascular
diagnostic instruments advanced along guide wire 12 to the targeted
treatment site(s). During the selected interventional procedure(s),
emboli or thrombi released from the treatment site are collected or
filtered by filter 82 while blood is allowed to flow unimpeded in
the downstream direction.
[0102] Upon completion of the interventional procedure, the embolic
filter assembly 80 may be removed from the vessel. A delivery
sheath 78, now functioning as a filter retrieval sheath, is
positioned over guide wire 12 and extended-length attachment sheath
90 and reinserted into the target vessel. Delivery sheath 78 is
advanced through the now-opened lesion and over filter assembly 80,
causing support hoop suspension strut 94 and support hoop 96 of
filter 82 to fold and collapse, thereby sealing the contents
captured within sac 51. Alternatively, after the open distal end 87
of delivery sheath 78 has crossed to the distal side of the lesion,
guide wire 12 and filter assembly 80 may be pulled proximally to
withdraw and retrieve filter assembly 80 into the opening at distal
end 87. Either before or after reinsertion of sheath 78, sheath 90,
if locked at the time, is unlocked. Delivery sheath 78, filter
assembly 80 and guide wire assembly 10 are then withdrawn from the
target vessel. The vasculature access site may then be closed by
techniques well-known in the art.
[0103] C. Repositioning and Adjusting the Filter Assembly and/or
the Guide Wire
[0104] During the course of positioning and deploying the subject
filters, as well as during the interventional procedure being
performed, various situations may arise wherein it is necessary to
correct or readjust the position of the filter or of the guide wire
or of both within the vessel. For example, the initial positioning
and deployment of the filter may not be optimal as it may have been
unintentionally deployed over the opening to a side branch vessel,
thereby blocking blood flow to the side branch vessel. The filter
may have been deployed in a location of the vessel that has an
inappropriate diameter size that will not allow proper engagement
between the filter support loop and the internal vessel wall. Also,
the section of vessel in which the filter is deployed may have
plaque that is easily dislodged upon deployment.
[0105] Furthermore, adjustment of the filter may be required for
reasons other than for a non-optimal deployment location. For
example, as the filter sac collects emboli it becomes more
resistant to blood flow. In time, particularly with respect to the
filter assembly embodiments employing a shorter-length attachment
sheath which are capable of some axial translation between proximal
and distal stop mechanisms, as well as with an unlocked
extended-length embodiment, the increase in pressure on the filter
sac may cause the filter assembly to migrate in a distal direction
and require readjustment of its position. Also, the filter may be
unintentionally moved proximally or distally by the common and
sometimes necessary manipulation of the guide wire, for example, in
the exchange of interventional instruments within the vessel. All
of the above circumstances may require adjusting the position of
the filter or the guide wire or both within the vessel, either in
the proximal or distal direction, during the course of the
procedure.
[0106] In addition to the axial translation of the filter and/or
guide wire, some rotational movement of either or both may be
necessary or unavoidable. During delivery of the filter assembly,
or before or after deployment of the filter, the guide wire may be
forced to rotate due to the anatomy of the vessel or there may
otherwise be a need to rotate guide wire. For example, as the guide
wire advances through a tortuous section of vessel, some
intentional or unintentional rotation of the guide wire may occur.
If such rotational movement does occur, the filter, when
undeployed, will maintain its rotational position within the
delivery sheath through which it is delivered. Maintaining its
position during delivery minimizes the risk of the filter sac
becoming entangled with the support hoop and the attachment sheath.
When the filter is in a deployed state, its ability to maintain its
rotational position within the vessel minimizes the chance of
scraping the vessel wall and of dislodging the support hoop
possibly creating an improper engagement between it and the vessel
wall.
[0107] III. Kits
[0108] Also provided by the subject invention are kits for use in
practicing the subject methods. A kit of the subject invention
includes at least one subject guide wire assembly and at least one
subject filter delivery, deployment and removal assembly. Other
kits may include two or more subject guide wire assemblies 10
without an accompanying filter delivery, deployment and removal
assembly 30. The guide wire assemblies may have respective guide
wires of varying dimensions, such as varying lengths. For those
kits having embolic filter system embodiments employing
shorter-length filter attachment sheaths (i.e., as disclosed in
FIGS. 1, 2, 3, and 4), multiple guide wire assemblies may be
provided having varying separation distances between proximal and
distal stops. Kits containing an embolic filter system embodiments
employing extended-length filter attachment sheaths (i.e., as
disclosed in FIGS. 1, 6 and 7), multiple filter assemblies may be
provided having varying attachment sheath lengths. Certain kits may
also include one or more vascular interventional systems, such as
an angioplasty system, along with a subject guide wire assembly 10
and a subject filter delivery, deployment and removal assembly 30.
Finally, the subject kits preferably include instructions for using
the subject device(s) and system(s) during an interventional
procedure to protect the patient against emboli. These instructions
may be present on one or more of the instructions for use included
in the kits, packaging, label inserts or containers present in the
kits, and the like.
[0109] IV. Advantages of the Subject Invention
[0110] Another advantage of the axial translation limitation system
of the present invention is that the configuration of the proximal
and distal stops is such that a low-profile guide wire assembly 10
can be maintained during delivery and retrieval of the guide wire
assembly, making the initial crossing of the lesion easier and
safer. This feature is particularly advantageous when the vessel at
the lesion site is close to being occluded.
[0111] Still another advantage of the present invention is that
guide wire 12 can make the first crossing of the lesion without the
added profile of an attached filter, thereby reducing the risk of
friction between the guide wire assembly and the lesion site and
thereby minimizing the risk of embolization of plaque from the
lesion site.
[0112] The combination of the movement systems and the movement
limitation systems of the present invention provide flexibility and
ease of use of the subject devices and systems, and reduce the
risks (e.g., the lack of a proper sealing engagement between the
internal vessel wall and the deployed filter, device profiles which
are too large or angular to cross safely over the lesion, the
unintentional movement of the filter while deployed, the distal
migration of the filter off the distal tip of the guide wire, the
proximal migration of the filter into the lesion site, etc.)
involved in intravascular procedures.
[0113] Thus, it is evident from the above description that the
subject inventions provide a significant contribution to the field
of embolic protection. The subject invention has been shown and
described herein in what is considered to be the most practical,
and preferred embodiments. It is recognized, however, that
departures may be made there from, which are within the scope of
the invention, and that obvious modifications will occur to one
skilled in the art upon reading this disclosure. Such departures
and modifications that come within the meaning and range of
equivalents of the disclosed concepts, are intended to included
within the scope of the appended claims.
* * * * *