U.S. patent application number 17/350736 was filed with the patent office on 2021-12-02 for embolic protection device.
The applicant listed for this patent is Innovative Cardiovascular Solutions, LLC. Invention is credited to Andy Black, Mark Carlson, Josh Greene, Kelly Jensen, Andy Leopold, William M. Merhi, Ben Rockwell.
Application Number | 20210370021 17/350736 |
Document ID | / |
Family ID | 1000005769810 |
Filed Date | 2021-12-02 |
United States Patent
Application |
20210370021 |
Kind Code |
A1 |
Merhi; William M. ; et
al. |
December 2, 2021 |
EMBOLIC PROTECTION DEVICE
Abstract
The present invention includes an embolic protection device
comprising a catheter having a self-expanding embolic filter that
is disposed around the catheter proximal to a distal portion,
wherein the embolic filter comprises a frame, and the frame defines
an opening of the embolic filter that faces the distal end of the
catheter; a deployment mechanism that is disposed around at least a
portion of the catheter, wherein the deployment mechanism is
longitudinally movable with respect to the catheter, the deployment
mechanism is configured to contain the embolic filter in a
collapsed configuration, and the embolic filter is configured to
self-expand upon the longitudinal retraction of the deployment
mechanism; and a wire coupled to the frame for expanding the size
or diameter of the embolic filter opening.
Inventors: |
Merhi; William M.; (SE Grand
Rapids, MI) ; Black; Andy; (North Barrington, IL)
; Carlson; Mark; (North Barrington, IL) ; Greene;
Josh; (North Barrington, IL) ; Jensen; Kelly;
(North Barrington, IL) ; Leopold; Andy; (North
Barrington, IL) ; Rockwell; Ben; (North Barrington,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Innovative Cardiovascular Solutions, LLC |
Kalamazoo |
MI |
US |
|
|
Family ID: |
1000005769810 |
Appl. No.: |
17/350736 |
Filed: |
June 17, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16930110 |
Jul 15, 2020 |
11071844 |
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17350736 |
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PCT/US2019/020952 |
Mar 6, 2019 |
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16930110 |
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62812391 |
Mar 1, 2019 |
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62639618 |
Mar 7, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2210/0014 20130101;
A61M 25/0041 20130101; A61B 2017/2215 20130101; A61B 2090/3966
20160201; A61B 17/00234 20130101; A61B 2017/2217 20130101; A61B
17/221 20130101; A61B 90/39 20160201; A61B 2017/00867 20130101 |
International
Class: |
A61M 25/00 20060101
A61M025/00; A61B 90/00 20160101 A61B090/00; A61B 17/00 20060101
A61B017/00 |
Claims
1-30. (canceled)
31. An embolic protection device comprising: a catheter having a
proximal end, a distal end, and a lumen extending from the proximal
end to the distal end along a longitudinal axis of the catheter,
wherein the lumen is configured to house a guidewire, and a distal
portion of the catheter that assumes a generally arcuate shape
being at least a semi-circle when the guidewire is at least
partially longitudinally retracted; a self-expanding embolic filter
that is disposed around the catheter, proximal to the distal
portion, wherein the embolic filter comprises a frame, wherein the
frame defines an opening of the embolic filter, and the frame
includes a fixed portion coupled to the catheter, proximal to the
distal portion, wherein the fixed portion does not move in a
longitudinal direction, and a movable portion continuous with the
fixed portion of the frame; a deployment mechanism that is disposed
around at least a portion of the catheter, wherein the deployment
mechanism is longitudinally movable with respect to the catheter,
the deployment mechanism is configured to contain the embolic
filter in a collapsed configuration, and the embolic filter is
configured to self-expand upon longitudinal retraction of the
deployment mechanism; a wire coupled to the movable portion of the
frame, wherein the wire is longitudinally movable with respect to
the catheter and urges the movable portion of the frame; when the
wire is longitudinally advanced, in a distal direction, to a first
position, the wire is configured to urge the movable portion of the
frame in a longitudinal direction and bend the frame longitudinally
towards the distal end of the catheter and laterally outward from
the catheter, such that the opening of the embolic filter generally
faces the distal end of the catheter and expands to a first
diameter; and when the wire is longitudinally advanced, in a distal
direction, to a second position distally farther than the first
position, the wire is configured to urge the movable portion of the
frame and extend the frame radially outward from the catheter, such
that the opening of the embolic filter expands to a second diameter
larger than the first diameter.
32. The embolic protection device of claim 31, wherein the wire,
when longitudinally advanced to the first position, is configured
to bend the frame so that the opening of the embolic filter defined
by the frame is substantially perpendicular to the longitudinal
axis of the catheter.
33. The embolic protection device of claim 31, wherein the wire,
when longitudinally retracted to a proximal position, is configured
to position the frame so that the opening of the embolic filter
defined by the frame is substantially parallel or angled less than
45 degrees with respect to the longitudinal axis of the
catheter.
34. The embolic protection device of claim 31, wherein the frame
includes two sides; and each side of the frame extending generally
in a first lateral direction away from the catheter and then
looping back on an opposite side around the catheter, and extending
generally in the opposite lateral direction before converging and
meeting to form the opening of the embolic filter having a
substantially elliptical, ovular or circular shape.
35. (canceled)
36. The embolic protection device of claim 31, further comprising
an outer catheter disposed around at least a portion of the
catheter and coaxial with the lumen of the catheter, wherein the
outer catheter is longitudinally slidable over the catheter; and
wherein the wire is coupled to a distal portion of the outer
catheter such that the wire is moved by the outer catheter sliding
over the catheter.
37. The embolic protection device of claim 36, further comprising
an inner catheter disposed between the outer catheter and the
catheter, wherein the inner catheter is longitudinally slidable
over the catheter; and a guide attached at one end to a distal
portion of the inner catheter so that the guide is moved by the
inner catheter sliding over the catheter, wherein the guide
slidably receives the movable portion of the frame causing the
guide to flex outwardly away from the catheter.
38. The embolic protection device of claim 37, wherein the guide is
a top guide and the embolic protection device further comprising a
bottom guide attached at one end to the catheter, wherein the
bottom guide and the top guide are arranged on opposite sides of
the catheter, and wherein the bottom guide receives the fixed
portion of the frame causing the bottom guide to flex outwardly
away from the catheter.
39. The embolic protection device of claim 31, wherein embolic
protection device has a handle, wherein the handle comprises a
mechanism configured to advance or retract the wire.
40. The embolic protection device of claim 37, further comprising:
a handle coupled to the proximal end of the catheter; a top pull
coupled to a proximal portion of the outer catheter and is
longitudinally movable within the handle; a bottom pull coupled to
a proximal portion of the inner catheter and is longitudinally
movable within the handle, wherein the bottom pull is in temporary
engagement with the top pull; when the top pull and the bottom pull
are engaged, the top pull and the bottom pull are moved in unison
by movement of a slider, which, in turn, urges the guide together
with the movable portion of the frame in the longitudinal direction
and expands the opening of the embolic filter to the first
diameter; and when the top pull and the bottom pull are disengaged,
the top pull is moved without the bottom pull by movement of the
slider, which, in turn, urges the movable portion of the frame in
the radial direction and expands the opening of the embolic filter
to the second diameter.
41. The embolic protection device of claim 31, wherein the catheter
extends through the opening of the embolic filter.
42. The embolic protection device of claim 31, wherein the distal
portion of the catheter comprises a radiopaque marker.
43. The embolic protection device of claim 42, wherein the
radiopaque marker comprises one or more circumferential bands.
44. The embolic protection device of claim 31, wherein the frame
comprises a shape memory material.
45. The embolic protection device of claim 31, wherein the embolic
filter comprises a filter medium, which comprises a semi-permeable
polyurethane material having a pore size of from about 100 microns
to about 150 microns.
46. The embolic protection device of claim 31, wherein the embolic
protection device comprises a longitudinal groove along an outer
surface of the embolic protection device.
47. The embolic protection device of claim 31, wherein the
deployment mechanism comprises a sheath that is circumferentially
disposed around at least a portion of the catheter, wherein the
sheath deploys the self-expanding embolic filter when the sheath is
at least partially longitudinally retracted.
48. The embolic protection device of claim 31, wherein the distal
portion of the catheter comprises one or more apertures that
communicates with the lumen of the catheter.
49-63. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 16/930,110, filed on Jul. 15, 2020, which is a continuation of
PCT application no. PCT/US2019/020952, filed Mar. 6, 2019, which
claims the benefit of U.S. provisional application No. 62/639,618,
filed on Mar. 7, 2018, and U.S. provisional application No.
62/812,391, filed on Mar. 1, 2019. Each of these documents is
hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] This application relates to embolic protection devices
including a catheter and methods of using such embolic protection
devices in medical procedures (e.g., closed-heart surgical
procedures).
BACKGROUND
[0003] Traditional pigtail catheters are used during percutaneous
cardiac procedures where the positioning of various instruments and
devices within the vasculature of a patient is important. These
pigtail catheters comprise a curved distal end that can rest within
the patient's anatomy (e.g., an artery (e.g., aorta)) and hold the
catheter in place while other instrumentation and devices are
delivered into the patient's vasculature. Some traditional pigtail
catheters include a lumen and small apertures at their distal ends
through which a contrast agent can be injected into a patient's
vasculature for imaging the relevant portion of the patient's
anatomy and identifying anatomical landmarks.
[0004] However, the use of traditional pigtail catheters in
percutaneous cardiac procedures often results in serious and
life-threatening complications for the patient. For example,
cerebral embolism is a common complication in cardiac procedures,
such as valve replacement and repair, where a traditional pigtail
catheter is deployed. During such procedures, plaque, calcium,
thrombi, or any combination thereof, in the vessels, valves, and/or
cardiac chambers can be dislodged by the catheter or other medical
devices introduced into the patient's vasculature. The dislodged
plaque, calcium, thrombi or any combination thereof can be carried
into the patient's brain via blood flow from the aorta and can
cause blockages therein leading to an embolic event such as stroke.
Approximately 2.9%-6.7% of patients undergoing transfemoral
transcatheter aortic-valve implantation (TAVI) have a stroke within
30 days, and even more (4.5%-10.6%) have a stroke within a year,
often leading to death. Furthermore, up to 85% of patients
undergoing TAVI have evidence of embolic phenomenon to the brain
based on neuroimaging studies. Although clinically silent, such
embolic phenomena are associated with cognitive decline (Astraci
2011; Ghanem 2010; Kahlert 2010; Rodes-Caban 2011).
[0005] Presently, there are a few devices on the market designed to
protect the brain, abdominal organs, and carotid arteries from
emboli, and these devices suffer from various significant
drawbacks. For instance, the Embrella Embolic Deflector.RTM.,
available from Edwards Lifesciences of Irvine, California, employs
a deflector that deflects emboli from the carotid arteries into the
descending aorta, but the device does not trap the emboli, so
emboli are free to travel to other areas of the body and cause
deleterious complications. The EMBOL-X.RTM., also available from
Edwards Lifesciences, employs a filtering screen, but this device
is designed for use in open heart procedures, which present
additional medical risks and increased morbidity. Additionally, the
use of multiple devices, for example a catheter for visualization
and a separate filter device, lengthens the procedure time and
increases the risk of complications to the patient.
SUMMARY
[0006] These and other needs are met by the present invention,
which presents an embolic protection device comprising a deployable
embolic filter that is disposed around a catheter having a distal
portion that can assume an arcuate configuration being at least a
semi-circle, and having a wire that is operable to manipulate the
embolic filter into a configuration that more fully engages a body
lumen.
[0007] The combination of the catheter and the embolic filter in
the same device may provide the benefits of both devices
individually, as well as provide a synergistic effect. For example,
the integration of the catheter and the embolic filter can decrease
the duration of the medical procedure and reduce the occurrence of
complications (e.g., complications caused by dislodged emboli). In
other examples, the expansion of the embolic filter may help to
anchor the catheter into position to provide a more accurate
position of the catheter than if the position of the catheter is
susceptible to the influences of blood flow, tissue movement, and
the like. In a valve replacement procedure, anchoring of the
catheter and more accurate positioning of the catheter may help
ensure that the valve prosthesis is properly positioned and
stabilized. In another example, the position of the catheter may
ensure that the filter is being properly positioned.
[0008] In some aspects, the embolic protection device comprises a
catheter, a self-expanding embolic filter coupled to the catheter,
a pull wire for reorienting the filter by bending a frame of the
filter, and an outer sheath movable with respect to the embolic
filter and the catheter. The outer sheath holds the embolic filter
in a collapsed configuration when surrounding the embolic filter
and is proximally retracted to deploy the embolic filter. The outer
sheath may recapture the embolic filter and any debris captured
therein by being distally advanced. The filter and outer sheath
might both be movable with respect to the catheter, for example to
be able to move the embolic filter longitudinally without having to
move the entire catheter longitudinally. The pull wire is
advantageous due to its ability to bend the frame, thereby facing
the filter opening towards the distal end of the device and causing
the embolic filter to more fully engage the body lumen.
[0009] In some aspects, the catheter has a proximal end and a
distal end. A lumen extends from the proximal end of the catheter
to the distal end of the catheter. In some embodiments, the lumen
may be configured to house a guidewire.
[0010] In some aspects, the catheter is a pigtail catheter. A
pigtail catheter is configured to curl at the distal end of the
catheter, forming a generally arcuate shape that is at least a
semi-circle. The pigtail may have a radiopaque marker viewable on
x-rays or other medical imaging devices. The radiopaque marker is
on the distal section of the curled pigtail in the form of a
longitudinal marker, circumferential bands, or the like. The
pigtail may additionally have one or more apertures to dispense
drugs and/or contrast agents through the lumen.
[0011] In some aspects, a guidewire is inserted through the
patient's skin and into a body lumen such as a femoral, radial, or
brachial artery and steered near a target site. The guidewire is
inserted into a lumen of the embolic protection device, and the
embolic protection device is pushed or tracked over the guidewire
to the target site. When the guidewire is retracted from at least
the distal portion of the catheter, the catheter assumes a
generally arcuate shape. The radiopaque marker on the catheter is
used to visualize and position the catheter. Once the catheter is
in position, the outer sheath is retracted to deploy the embolic
filter and the pull wire is retracted to bend the frame of the
filter to position the distal opening of the filter across the
vessel. The user can then perform a procedure such as valve
replacement, valve repair, radio frequency ablation, and the like.
When the procedure is completed, the pull wire is advanced and the
outer sheath is advanced to recapture the embolic filter and any
debris trapped in the embolic filter. The device is then retracted
from the vessel, with the catheter being atraumatic to vessels
during retraction.
[0012] Another aspect is a method of capturing embolic debris
during a closed-heart surgical procedure comprising inserting the
distal end of the catheter of the embolic protection device into a
body lumen. The method further comprises allowing the embolic
filter to assume an expanded, deployed configuration and retracting
the pull wire to bend the frame of the filter, so that a distal
opening of the filter spans the body lumen.
[0013] In some aspects, the embolic protection device comprises a
catheter, a self-expanding embolic filter coupled to the catheter,
a push wire for reorienting the filter by bending a frame of the
filter in a longitudinal direction and extending the frame in a
radial direction, and an outer sheath movable with respect to the
embolic filter and the catheter. The outer sheath holds the embolic
filter in a collapsed configuration when surrounding the embolic
filter and is proximally retracted to deploy the embolic filter.
The outer sheath may recapture the embolic filter and any debris
captured therein by being distally advanced. The push wire is
advantageous due to its ability to bend and extend the frame,
thereby facing the filter opening towards the distal end of the
device and causing the embolic filter to more fully engage the body
lumen.
[0014] In some aspects, the catheter has a proximal end and a
distal end. A lumen extends from the proximal end to the distal end
along a longitudinal axis of the catheter. In some embodiments, the
lumen may be configured to house a guidewire.
[0015] In some aspects, the catheter is a pigtail catheter. A
pigtail catheter is configured to curl at the distal end of the
catheter, forming a generally arcuate shape that is at least a
semi-circle. The pigtail may have a radiopaque marker viewable on
x-rays or other medical imaging devices. The radiopaque marker is
on the distal section of the curled pigtail in the form of a
longitudinal marker, circumferential bands, or the like. The
pigtail may additionally have one or more apertures to dispense
drugs and/or contrast agents through the lumen.
[0016] In some aspects, a guidewire is inserted through the
patient's skin and into a body lumen such as a femoral, radial, or
brachial artery and steered near a target site. The guidewire is
inserted into a lumen of the embolic protection device, and the
embolic protection device is pushed or tracked over the guidewire
to the target site. When the guidewire is retracted from at least
the distal portion of the catheter, the catheter assumes a
generally arcuate shape. The radiopaque marker on the catheter is
used to visualize and position the catheter. Once the catheter is
in position, the outer sheath is retracted to deploy the embolic
filter and the push wire is advanced to bend and extend the frame
of the filter to position the distal opening of the embolic filter
across the vessel. The user can then perform a procedure such as
valve replacement, valve repair, radio frequency ablation, and the
like. When the procedure is completed, the push wire is retracted
and the outer sheath is advanced to recapture the embolic filter
and any debris trapped in the embolic filter. The device is then
retracted from the vessel, with the catheter being atraumatic to
vessels during retraction.
[0017] Another aspect is a method of capturing embolic debris
during a closed-heart surgical procedure comprising inserting the
distal end of the catheter of the embolic protection device into a
body lumen. The method further comprises allowing the embolic
filter to assume an expanded, deployed configuration and advancing
the push wire to bend and extend the frame of the filter, so that a
distal opening of the filter spans the body lumen.
BRIEF DESCRIPTION OF THE FIGURES
[0018] The following figures are provided by way of example and are
not intended to limit the scope of the claimed invention.
[0019] FIGS. 1A and 1B illustrate partial side views of an
embodiment of an embolic protection device of the present
invention. In FIG. 1A, an embolic filter of the embolic protection
device is illustrated in a collapsed (undeployed) configuration. In
FIG. 1B, the embolic filter is illustrated in an expanded
(deployed) configuration wherein a pull wire affixed to a frame of
the embolic filter is advanced to a distal position so that the
frame assumes it's self-expanded and undeflected (i.e., unbent)
configuration.
[0020] FIG. 1C illustrates a side perspective view of an embodiment
of an embolic filter of the present invention assuming a partially
deflected (i.e., partially bent) configuration wherein the pull
wire affixed to the frame of the embolic filter is partially
longitudinally retracted to a proximal position.
[0021] FIG. 1D illustrates a transverse cross-sectional view of an
embodiment of an embolic filter of the present invention assuming a
fully deflected (e.g., fully bent) configuration wherein the pull
wire is fully longitudinally retracted thereby deflecting the
filter.
[0022] FIGS. 1E and 1F illustrate front views of an embodiment of
an embolic filter frame of the present invention. In FIG. 1E, the
filter frame is undeployed wherein the frame is collapsed and
enclosed by an outer sheath. In FIG. 1F, the outer sheath is
longitudinally retracted and the filter frame is deployed to its
self-expanded configuration.
[0023] FIGS. 2A-2B illustrate partial side views of an embodiment
of an embolic protection device of the present invention comprising
a shoulder.
[0024] FIGS. 3A-3D illustrate partial side views of an embodiment
of an embolic protection device of the present invention comprising
an intermediate tube.
[0025] FIGS. 4A-4C illustrate partial side views of an embodiment
of an embolic protection device of the present invention comprising
a deflector.
[0026] FIG. 5A illustrates an embodiment of an embolic protection
device comprising a handle. FIG. 5B illustrates a distal portion of
the embolic protection device comprising the embolic filter and
pigtail catheter.
[0027] FIG. 6A illustrates a partial side view of an embodiment of
an embolic protection device of the present invention with an
embolic filter in a collapsed (undeployed) configuration.
[0028] FIGS. 6B and 6C illustrate a side view and a front end view
of the embolic filter in an self-expanded (deployed) configuration,
respectively, wherein a push wire coupled to a frame of the embolic
filter is retracted to a proximal position so that the frame
assumes an undeflected (i.e., unbent) configuration.
[0029] FIGS. 6D and 6E illustrate a side view and a front end view
of the embolic filter in an partially expanded configuration,
respectively, wherein the push wire coupled to the frame of the
embolic filter is longitudinally advanced to a first distal
position so that the frame assumes a deflected (i.e., bent)
configuration.
[0030] FIGS. 6F and 6G illustrate a side view and a front end view
of the embolic filter in an fully expanded configuration,
respectively, wherein the push wire coupled to the frame of the
embolic filter is longitudinally advanced to a second distal
position farther than the first distal position shown in FIG. 6C so
that the frame assumes an extended configuration.
[0031] FIGS. 7A-7C illustrate partial side views of an embodiment
of an embolic protection device of the present invention having an
actuating mechanism for operating an embolic filter.
[0032] FIGS. 8A and 8B illustrate an embodiment of an embolic
protection device of the present invention having a handle for
manually operating an embolic filter.
[0033] FIGS. 8C-8F illustrate an example of the handle.
[0034] FIGS. 9A-9E illustrate a stepwise method of using an embolic
protection device of the present invention.
[0035] FIG. 10 illustrates the deflection and capture of embolic
debris by an embolic protection device of the present invention
comprising a deflector.
[0036] FIG. 11 illustrates the deflection and capture of embolic
debris by an embolic protection device of the present invention
wherein a second catheter device is present.
[0037] FIGS. 12A-12D illustrate a stepwise method of using an
embolic protection device of the present invention operating an
embolic filter.
[0038] FIGS. 13A and 13B are photographs of distal portions of
embolic protection devices of the present invention situated within
a cadaver's vasculature according to Example 1. In FIG. 13A, the
embolic protection device comprises a longitudinal groove in which
a second catheter is inserted alongside the embolic protection
device. In FIG. 13B, the second catheter is situated adjacent to
the embolic protection device that lacks a longitudinal groove.
[0039] FIG. 14 is a bar graph of performance data of an embolic
protection device of the present invention (the EPD-1 device)
according to Example 2.
[0040] FIGS. 15A-15J are images generated from diffusion-weighted
magnetic resonance imaging (DW-MRI) of representative subjects
according to Example 2.
[0041] FIG. 16A is a photograph of thrombi captured by an embolic
protection device of the present invention (the EPD-1 device)
according to Example 2.
[0042] FIG. 16B is a photograph of a collagenous fragment captured
within the filter of the embolic protection device (the EPD-1
device) according to Example 2.
[0043] Like reference numerals in the various drawings indicate
like elements.
DETAILED DESCRIPTION
[0044] The present invention provides an embolic protection device
and methods of using the embolic protection device for capturing
embolic debris during surgical procedures.
I. DEFINITIONS
[0045] As used herein, the term "self-expanding" means to increase,
spread out, or unfold from a collapsed state upon the withdrawal or
removal of a restricting or confining force.
[0046] As used herein, the term "closed-heart" refers to any
surgical procedure involving the heart, wherein the chest cavity is
not opened.
[0047] As used herein, the term "woven" refers to any material that
comprises a plurality of strands, wherein the strands are
interlaced to form a net, mesh, or screen. Without limitation,
examples of woven materials include netting or mesh comprising a
polymer, metal, or metal alloy.
[0048] As used herein, the term "non-woven" refers to any material
that comprises a continuous film. Non-woven material may be
permeable, semi-permeable, or non-permeable. For example, permeable
or semi-permeable non-woven material may optionally include one or
more pores through which a fluid may pass.
[0049] As used herein, the term "alloy" refers to a homogenous
mixture or solid solution produced by combining two or more
metallic elements, for example, to give greater strength or
resistance to corrosion. For example, alloys include brass, bronze,
steel, nitinol, chromium cobalt, MP35N, 35NLT, elgiloy, and the
like.
[0050] As used herein, "nitinol" and "nickel titanium" are used
interchangeably to refer to an alloy of nickel and titanium.
[0051] As used herein, "chromium cobalt" refers to an alloy of
chromium and cobalt.
[0052] As used herein, "MP35N" refers to an alloy of nickel and
cobalt.
[0053] As used herein, "35NLT" refers to a cobalt-based alloy that
may also comprise chromium, nickel, molybdenum, carbon, manganese,
silicon, phosphorus, sulfur, titanium, iron, and boron.
[0054] As used herein, "elgiloy" refers to an alloy of cobalt,
chromium, nickel, iron, molybdenum, and manganese.
[0055] As used herein, a "body lumen" refers to the inside space of
a tubular structure in the body, such as an artery, intestine,
vein, gastrointestinal tract, bronchi, renal tubules, and urinary
collecting ducts. In some instances, a body lumen refers to the
aorta.
II. EMBOLIC PROTECTION DEVICES
[0056] Although certain embodiments and examples are described
below, those skilled in the art will recognize that the disclosure
extends beyond the specifically disclosed embodiments and/or uses
and obvious modifications and equivalents thereof. Thus, it is
intended that the scope of the disclosure herein presented should
not be limited by any particular embodiments described below.
[0057] For purposes of this disclosure, the terms "upper," "lower,"
"right," "left," "rear," "front," "vertical," "horizontal," and
derivatives thereof shall relate to the invention as oriented in
FIGS. 1B and 1F (or in FIGS. 6B and 6C). However, it is to be
understood that the invention may assume various alternative
orientations, except where expressly specified to the contrary.
Also, for purposes of this disclosure, the term "coupled" (in all
of its forms, couple, coupling, coupled, etc.) generally means the
joining of two components (electrical or mechanical) directly or
indirectly to one another. Such joining may be stationary in nature
or movable in nature; may be achieved with the two components
(electrical or mechanical) and any additional intermediate members
being integrally formed as a single unitary body with one another
or with the two components; and may be permanent in nature or may
be removable or releasable in nature, unless otherwise stated.
[0058] FIGS. 1A and 1B illustrate embodiments of an embolic
protection device 100. In these embodiments, the device 100
comprises a catheter 102 (e.g., a pigtail catheter) having a
proximal end 114, a distal end 116, and a lumen 118 extending from
the proximal end 114 to the distal end 116. The lumen 118 may be
configured to house a guidewire 990 (see FIGS. 9A and 9B) that is
longitudinally moveable through this lumen to coil or straighten
the distal portion 104 of the catheter 102 depending on whether the
guidewire is retracted (to coil the distal portion) or extended (to
straighten the distal portion). In some embodiments, the catheter
102 includes a distal portion 104 configured to assume a generally
arcuate shape being at least a semi-circle. A side wall of the
catheter 102 may optionally include one or more apertures 108 in
the distal portion 104 that are configured to deliver one or more
fluids (e.g., imaging dye, contrast agent, oxygenated blood,
saline, any combination thereof, or the like) to a body lumen 992
(see FIG. 9A). The apertures 108 (the plural intended to include
embodiments in which the distal portion includes one aperture 108)
are in fluid communication with the lumen 118. In some embodiments,
the distal portion 104 of the catheter 102 includes one or more
radiopaque markers 106. In some embodiments, the radiopaque markers
106 are wrapped around the circumference of the distal portion of
the catheter and can have the same or different widths. In other
embodiments, the radiopaque markers are co-linear with the lumen
and extend to the distal end of the catheter. The device 100
further comprises a self-expanding embolic filter 110 defined by a
frame 124 and a filter medium 126, and a deployment mechanism 112
(e.g., a longitudinally retractable outer sheath or a
longitudinally retractable ring). The embolic filter 110 is
disposed around the catheter 102.
[0059] As illustrated in FIG. 1B, in its deployed configuration,
the embolic filter 110 includes a distal opening 140 that is
defined by the frame 124, faces the distal end 116 of the catheter
102, and extends proximally from the distal opening 140 to a closed
proximal end 142. The device 100 further comprises a pull wire 122
that is coupled to the frame 124 and can be retracted to deflect or
bend the frame 124 and change the orientation and shape of the
distal opening 140.
[0060] In some embodiments, retracting the pull wire 122 may cause
the distal opening 140 of the embolic filter 110 to engage at least
a portion of the interior body lumen 992 (see FIG. 9D) wall. FIG.
1B illustrates the pull wire 122 in an advanced, i.e., un-retracted
or self-expanded, configuration with the frame oriented generally
to extend in a distal longitudinal direction, albeit angled back
somewhat (e.g., less than about 45 degrees) in a lateral direction.
The catheter 102 may be partially surrounded towards its proximal
end 114 by a support catheter 150 that terminates at a head 152,
proximal to the distal portion 104 of the catheter 102. The support
catheter 150 may be made of a thicker, stiffer material to add
rigidity and provide a protective or supporting layer surrounding
the catheter 102.
[0061] FIG. 1C illustrates the embolic filter 110 deployed (e.g.,
self-expanded) by retraction of the deployment mechanism (e.g.,
outer sheath) 112 with the frame 124 partially deflected, i.e.,
partially bent, by retraction of the pull wire 122. The pull wire
122 is coupled to the frame 124 at a distal coupling 134. The
distal opening 140 is primarily defined by a first portion 132 of
the frame 124. The first portion 132 of the frame 124 defines a
shape of the distal opening 140 that is substantially elliptical
(i.e., shaped like an ellipse), or alternatively, substantially
oval-shaped or circular. In this embodiment, the portion 132 of the
frame 124 may be substantially elliptical and may terminate a
V-shaped point at its proximal end, i.e., the portion 132 of the
frame 124 may invert its curvature at one end of its substantially
elliptical shape (e.g., at its distal end) and come to a point at
its proximal end. The distal opening 140 may substantially be
defined by the frame 124, but may span across the frame 124
adjacent to the section of the frame 124 that comes to a point. The
filter medium 126 may define a portion of the distal opening 140
where the filter medium 126 spans across the frame 124, i.e.,
adjacent to a point of attachment of the frame 124 to the catheter
102 or support catheter 150.
[0062] The attachment of the frame 124 to the support catheter 150
(or alternatively, directly to the catheter 102) is accomplished
via a second portion 130 of the frame 124, which encircles the
support catheter 150 (or catheter 102) and is at an angle with
respect to the longitudinal axis of the catheter 102. The second
portion 130 of the frame 124 may be fixed in its position by
friction and by tension of the embolic filter 110 in the lateral
and/or longitudinal directions. In other embodiments, the fixed
attachment of the second portion 130 of the frame 124 to the
support catheter 150 (or catheter 102) may also be accomplished via
adhesives, welding, or the like.
[0063] The first portion 132 of the frame 124 may extend in a first
lateral direction away from the catheter 102 and away from the
second portion 130 of the catheter 102 and loop back across the
catheter 102 and extend in the opposite lateral direction. In this
embodiment, the first portion 132 of the frame 124 comprises two
sides (132a, 132b) that each extend generally in a first lateral
direction away from the catheter 102 and then loop back on opposite
sides around the catheter 102 and extend generally in the opposite
lateral direction before converging and meeting to form the
substantially elliptical shape. As shown in FIG. 1F, the embolic
filter 110 is symmetrical about the pull wire 122. For ease of
discussion, the embolic filter 110 is referred as having a left
side and a right side. Elements on the left side of the embolic
filter 110 are mirrored by elements on the right side of the
embolic filter 110.
[0064] When the pull wire 122 is in its advanced state (or
partially, but not fully, retracted state), the frame 124 extends
in a distal longitudinal direction as it extends from its
attachment to the catheter 102 (or support catheter 150). When the
pull wire 122 is in its retracted state (i.e., fully retracted)
(see FIG. 1D and FIG. 9E), the frame 124 extends in a distal
longitudinal direction near its point of attachment to the catheter
102, but then is bent such that it extends substantially
perpendicular to the longitudinal axis of the catheter 102.
[0065] FIG. 1D presents a cross-sectional view of the distal
opening 140 of the embolic filter 110 when the embolic filter 110
assumes an expanded configuration and when the pull wire 122 is in
a fully retracted state, fully deflecting (or bending) the frame
124. The pull wire 122 deflects or bends the frame 124 in a
proximal longitudinal direction and laterally outward. In a fully
deflected configuration (i.e., when the pull wire 122 is fully
retracted), the distal opening 140 of the embolic filter 110 may be
substantially perpendicular to the longitudinal axis of the
catheter 102 and may span laterally across the body lumen 992 (see
FIGS. 9D and 9E), substantially perpendicular to the longitudinal
axis of the body lumen 992. The fully deflected (or bent)
configuration may allow the embolic filter 110 to more fully engage
the body lumen 992. In this fully deflected configuration, the
distal opening 140 is substantially perpendicular to the
longitudinal axis of the catheter 102. In the fully deflected
configuration, the width, x, across the distal opening 140 may be
increased compared to the corresponding dimension in the
undeflected configuration. Likewise, in the fully deflected
configuration, the length, y, across the distal opening 140 may be
decreased compared to the corresponding dimension in the
undeflected configuration. By increasing the width, x, in the bent
configuration, the frame 124 defining the distal opening 140 may
more fully engage the body lumen 992.
[0066] In the embodiments illustrated in each of FIGS. 1A-1D, the
catheter 102 extends through the distal opening 140 of the embolic
filter 110, and the frame 124 extends away from the catheter 102 in
a first lateral direction and then curves back around the catheter
102 in the opposite direction.
[0067] The embolic protection device 100, with the embolic filter
110 deployed, i.e., the deployment mechanism 112 is retracted), may
assume an undeflected (FIG. 1B), partially deflected (FIG. 1C), or
fully deflected (FIGS. 1D and 5E) configuration. These
configurations are achieved by engaging the pull wire 122 to a
fully advanced, partially retracted (or partially advanced), or
fully retracted state. In the fully advanced state, the pull wire
122 is in a distal position. In the fully retracted state, the pull
wire 122 is in a proximal position. When longitudinally retracted
to a proximal position, the pull wire 122 is configured to deflect
(or bend) the frame 124 so that the distal opening 140 of the
filter 110 is substantially perpendicular to the longitudinal
direction of the catheter 102 and the distal opening 140 faces the
distal end 116 of the catheter 102. When longitudinally advanced to
a distal position, the pull wire 122 is configured to position the
frame 124 so that the distal opening 140 of the filter 110 defined
by the frame 124 is substantially parallel or angled less than
about 45 degrees with respect to longitudinal direction of the
catheter 102.
[0068] In some embodiments, the distal opening 140 of the embolic
filter 110 has a diameter of from about 2 cm to about 6 cm (e.g.,
from about 2.5 cm to about 5 cm or about 4.5 cm). The embolic
filter 110 can comprise any suitable size or diameter to
accommodate anatomic variability in patients' body lumens 992 (see
FIG. 9C). In some embodiments, the embolic filter 110 is coupled to
the catheter 102 at the proximal and/or distal ends of the embolic
filter 110 and/or at any other points there between. For example,
the embolic filter 110 may be coupled to the catheter 102 via the
frame 124, specifically the second portion 130 of the frame 124
(distal attachment) and also coupled to the catheter 102 via the
filter medium 126 at an attachment point within the sheath 112.
[0069] FIGS. 1E and 1F illustrate the frame 124 of the embolic
filter 110. In the embodiment illustrated in FIG. 1E, the frame 124
is collapsed within the outer sheath 112, i.e., with the sheath 112
advanced over the frame 124. In the embodiment illustrated in FIG.
1F, the frame 124 is deployed outside the sheath 112, i.e., with
the sheath 112 retracted. The pull wire 122 is coupled to the frame
124 at a distal coupling 134. The pull wire 122 may be coupled to
the frame 124 at the distal coupling 134 by a variety of methods,
including by means of a hole in the frame 124 through which the
pull wire 122 is threaded and crimped to hold it in place. The
distal coupling 134 may also include a variation in the curvature
of the frame 124, i.e., by inverting the curvature of the frame 124
and coming to a point. This curvature, along with the curvature of
the frame 124 adjacent to the point of attachment of the frame 124
to the catheter 102, may aid in collapsing the frame 124 in order
to advance the sheath 112 over the embolic filter 110. In some
embodiments, the frame 124 comprises a shape memory material (e.g.,
a metal alloy or polymer). Examples of shape memory materials
include, without limitation, nitinol, chromium cobalt, and/or other
metal alloys such as MP35N, 35NLT, elgiloy, and the like. In some
embodiments, the frame 124 is laser cut from a tube or a sheet.
[0070] FIGS. 2A and 2B illustrate embodiments of an alternative
deployment mechanism for an embolic protection device 200
comprising a catheter 202, an embolic filter 210, and a movable
outer sheath 212. In some embodiments, the outer sheath 212 can
include an optional lip 260 protruding inwardly from the distal end
of the outer sheath 212. The catheter 202 can include one or more
shoulders 262 (e.g., a distal shoulder 262a and a proximal shoulder
262b) protruding outwardly from an outer wall of the catheter 202.
The lip 260 of the outer sheath 212 is configured to engage the
shoulder or shoulders 262 of the catheter 202 to inhibit or prevent
the outer sheath 212 from moving excessively in either the proximal
or distal direction. The lip 260 and shoulder 262 may be arcuate,
pronged, and combinations thereof, and the like.
[0071] In some embodiments, the outer sheath 212 and/or the
catheter 202 comprise nubs and/or detents configured to provide
information to the user about the longitudinal position of the
outer sheath without inhibiting further movement. In some
embodiments, the outer sheath 212 and the catheter 202 comprise
lips 260, shoulders 262, and detents and nubs (e.g., to inhibit
longitudinal movement of the outer sheath 212 excessively in either
direction, and to provide information about the extent of movement
of the outer sheath 212 relative to the catheter 202 (e.g., 1/2
retracted, 1/4 retracted, etc.)).
[0072] Benefits of the outer sheath 212 deployment mechanism may
include its simplicity, ease of operation, and small number of
moving parts. The embolic protection device 200 is well-suited for
use in conjunction with delicate cardiac procedures having serious
risks. As the duration of the procedure increases, the risk of
complications typically increases as well. Therefore, it can be
advantageous that the user be able to quickly and easily deploy and
recapture the embolic filter 210. A more complicated device could
be more difficult to operate and could be more likely to
malfunction or cause adverse effects. The ability to move the outer
sheath 212 relative to the embolic filter 210 can advantageously
allow the user to partially recapture the embolic filter 210, for
example to adjust the width of the distal opening 140. In some
embodiments, narrowing the distal opening 140 allows the user to
introduce a second catheter or instrument to the patient's body
lumen 992 (see FIG. 9D) and maneuver the second catheter or
instrument around and past the catheter 202 and embolic filter 210,
as described herein. In some embodiments, an embolic protection
device as described herein may have a longitudinally extending
groove (not shown) along its surface, e.g., along the catheter 102,
along the support catheter 150 or along the deployment mechanism
(e.g. outer sheath) 112. In such embodiments, a second catheter or
instrument may be inserted while engaging the groove to guide the
second device alongside the embolic protection device.
[0073] FIGS. 3A-3D illustrate embodiments of an embolic protection
device 300 in which an embolic filter 310 is movably coupled to a
catheter 302 by way of a frame 324 and is longitudinally movable
with respect to the catheter 302. In some embodiments, the embolic
filter 310 is coupled to an intermediate tube 330 that at least
partially circumferentially surrounds the catheter 302. The
intermediate tube 330 is longitudinally movable with respect to the
catheter 302. An outer sheath 312 is configured to at least
partially circumferentially surround both the catheter 302 and the
intermediate tube 330. The intermediate tube 330 and the outer
sheath 312 can be moved simultaneously and independently. The
longitudinal position of the embolic filter 310 with respect to the
catheter 302 can be adjusted while the embolic filter 310 is in the
collapsed configuration or in a deployed or partially deployed,
expanded configuration. In some embodiments, the perimeter of the
distal opening of the embolic filter 310 comprises one or more
radiopaque markers to allow the user to visualize the position of
the distal opening, for example, with respect to various anatomical
landmarks. For example, if the user is performing a procedure on a
patient's aortic valve and wants to prevent emboli from entering
the cerebral arteries, the radiopaque markers can be used to ensure
the distal opening of the embolic filter 310 is positioned in the
ascending aorta upstream from the carotid arteries.
[0074] FIG. 3A illustrates the embolic filter 310 confined in a
closed configuration by the outer sheath 312 and a distal end of
intermediate tube 330 at position (a). If the intermediate tube 330
is held stationary at position (a), the outer sheath 312 can be
retracted to deploy the embolic filter 310, as shown in FIG. 3C. If
the intermediate tube 330 and outer sheath 312 are instead moved
simultaneously, the embolic filter 310 remains confined by the
outer sheath 312 while the longitudinal position of the embolic
filter 310 is adjusted. For example, FIG. 3B illustrates the
embolic filter 310 still confined by outer sheath 312, while the
intermediate tube 330 has been retracted so that the distal end of
the intermediate tube 330 is at position (b). If the intermediate
tube 330 is then held stationary at position (b), the outer sheath
312 can be retracted to deploy the embolic filter 310, as shown in
FIG. 3D. The intermediate tube 330 and outer sheath 312 can be
moved to adjust the longitudinal position of the embolic filter 310
in a deployed or partially deployed configuration. For example, the
intermediate tube 330 and outer sheath 312 can be moved
simultaneously to retract the intermediate tube 330 from the
position as shown in FIG. 3C to position (b) as shown in FIG.
3D.
[0075] In addition to those described in detail herein, a wide
variety of deployment mechanisms for embolic filters are possible.
For example, a deployment system may comprise a portion of an
annular sheath including inward end protrusions that are guided in
tracks along the catheter body. Certain such embodiments may
advantageously reduce the profile of the catheter. For another
example, a deployment system may comprise a threaded sheath that
longitudinally moves upon twisting by the user. For yet another
example, a deployment system may comprise a plurality of annular
bands that can capture the embolic filter longitudinally and/or
circumferentially. Combinations of the deployment systems described
herein and other deployment systems are also possible.
[0076] FIGS. 4A-4C illustrate another embodiment of an embolic
protection device 400 comprising a catheter 402, a deflector 460,
an embolic filter 410, and a movable outer sheath 412. In some
embodiments, the embolic protection device 400 is similar to
embolic protection device 100 with the addition of the deflector
460.
[0077] Various types and designs of deflectors can be used with an
embolic protection device such as embolic protection device 400.
Such deflectors can have different shapes and/or sizes and can vary
in where and how they are coupled to the catheter. For example,
deflectors can be made in various sizes, for example to accommodate
differences in patient anatomy. In some embodiments, the deflector
comprises a shape memory material, for example including nitinol,
chromium cobalt, and/or alloys such as MP35N, 35NLT, elgiloy, and
the like. In some embodiments, the deflector comprises a porous
membrane, for example a semi-permeable polyurethane
membrane/material, mounted to a self-expanding frame, for example a
frame comprising a shape memory material.
[0078] An example of the deflector 460 shown in FIGS. 4A-4C has a
generally butterfly or elliptical shape with two wings or petals
460a and 460b extending to either side of a central axis 464. The
wings or petals 460a and 460b may be the same or different in size
shape, material, and the like. The deflector 460 is coupled to a
side of the catheter 402 via an elongate member 462 that is coupled
(e.g., by adhering, welding, soldering, coupling using a separate
component, combinations thereof, and the like) at one end to the
central axis 464 of the deflector 460 and at the other end to the
catheter 402. In some embodiments, the elongate member 462
comprises a shape memory material, for example including nitinol,
chromium cobalt, and/or alloys such as MP35N, 35NLT, elgiloy, and
the like that is configured (e.g., shape set) to bias the deflector
away from the catheter 402. The deflector 460 is configured to
release to an open configuration, shown in FIGS. 4B and 4C, when
not confined by, for example, an outer sheath 412. In some
embodiments, the deflector 460 is configured to fold along the
central axis 464 away from the elongate member 462 so that the
wings or petals 460a and 460b come together and the deflector 460
can be contained in, for example, an outer sheath 412, as shown in
FIG. 4A. As shown in FIG. 4A, the deflector 460 can initially be
folded and contained in the outer sheath 412 such that the wings or
petals 460a and 460b are positioned distal to the central axis 464.
In some embodiments, the deflector 460 can initially be folded in
the opposite direction such that the wings or petals 460a and 460b
are positioned proximal to the central axis 464.
[0079] In some embodiments, the catheter 402 is a pigtail-type
catheter as shown in FIGS. 4A and 4B and described herein. The
catheter 402 includes a distal portion 404 configured to assume a
generally arcuate shape being at least a semi-circle. In some
embodiments, the distal portion 404 of the catheter 402 includes
one or more radiopaque markers 406. A side wall of the catheter 402
may optionally include one or more apertures 408 in the distal
portion 404 that are configured to deliver one or more fluids
(e.g., imaging dye, contrast agent, oxygenated blood, saline, any
combination thereof, or the like) to a body lumen.
[0080] The catheter 402 has a proximal end 414 and a distal end
416. As shown in the FIG. 4B, an example of the catheter 402 is
partially surrounded towards its proximal end 414 by a support
catheter 450 that terminates at a head 452, proximal to the distal
portion 404 of the catheter 402. The support catheter 450 may be
made of a thicker, stiffer material to add rigidity and provide a
protective or supporting layer surrounding the catheter 402.
[0081] As illustrated in FIG. 4B, the embolic filter 410 comprises
a frame 424 and a filter medium 426. In its deployed configuration,
the embolic filter 410 includes a distal opening 440 defined by the
frame 424, faces the distal end 416 of the catheter 402, and
extends proximally from the distal opening 440 to a closed proximal
end 442. The device 400 further comprises a pull wire 422 that is
coupled to the frame 424 and can be retracted to deflect or bend
the frame 424 and change the orientation and shape of the distal
opening 440, in manner similar to that described above with
reference to FIGS. 1B-1D.
[0082] In some embodiments, the deflector 460 and embolic filter
410 can be coupled to another type of catheter, for example a
catheter without a distal portion configured to assume an arcuate
shape. The embolic filter 410 can be similar to the embolic filters
110 and 210 shown in FIGS. 1A-1D; FIGS. 2A and 2B; and described
herein. In some embodiments, the embolic filter 410 is coupled to
the catheter 402 proximal to the deflector 460, for example as
shown in FIGS. 4A-4B. In some embodiments, the embolic filter 410
is coupled to the catheter 402 distal to the deflector 460. The
embolic filter 410 is coupled so that it is disposed around the
catheter 402. This configuration advantageously allows the embolic
filter 410 to engage the interior body lumen 992 (see FIG. 9D)
wall, as the position of the catheter 402 within the body lumen 992
(see FIG. 9D) may be affected by the deployed deflector 460.
[0083] The combination of the deflector 460 and the embolic filter
410 can advantageously provide additional protection against
potential complications resulting from thrombi in the blood stream.
For example, if the embolic filter 410 (e.g., the distal end of the
embolic filter 410) is distal to the deflector 460, the embolic
filter 410 can serve as the primary means of embolic protection and
the deflector 460 can serve as the secondary means of embolic
protection. If some blood is able to flow around the embolic filter
410 rather than through it, the deflector 460 serves as a secondary
(or back-up) protection device and prevents any debris not captured
by the embolic filter 410 from entering the cerebral arteries and
traveling to the brain. If the embolic filter 410 is proximal to
the deflector 460, the deflector 460 can serve as the primary means
of embolic protection and the embolic filter 410 can serve as the
secondary means of embolic protection. The deflector 460 first
deflects debris away from the carotid arteries, then the embolic
filter 410 captures debris (e.g., including deflected debris) as
blood flows through the descending aorta.
[0084] In some embodiments, the catheter 402 and outer sheath 412
can have lips, shoulders, nubs, and/or detents, for example similar
to those shown in FIGS. 2A and 2B and described herein. For
example, lips, shoulders, nubs, and/or detents can be positioned on
the catheter 402 distal to the deflector 460, between the deflector
460 and embolic filter 410, and proximal to the embolic filter 410
to engage corresponding lips, shoulders, nubs, and/or detents on
the outer sheath 412. The lips, shoulders, nubs, and/or detents can
advantageously provide the user with information about the
longitudinal position of the outer sheath 412 so that the user
knows when neither, one, or both of the deflector 460 and embolic
filter 410 are deployed. In some embodiments, either or both of the
deflector 460 and embolic filter 410 can be movably coupled to the
catheter 402 via an intermediate tube similar to that shown in
FIGS. 3A-3D and described herein.
[0085] An embodiment of an embolic protection device 500, similar
to the embolic protection device 100 in FIGS. 1A-1E, is shown in
FIGS. 5A and 5B. The embolic protection device 500 comprises a
catheter 502, an embolic filter 510, a movable outer sheath 512,
and a handle 570. In some embodiments, the catheter 502 is a
pigtail-type catheter as shown in the close up view of FIG. 5B and
described herein. The catheter 502 includes a distal portion 504
configured to assume a generally arcuate shape being at least a
semi-circle. In some embodiments, the distal portion 504 of the
catheter 502 includes one or more radiopaque markers 506. A side
wall of the catheter 502 may optionally include one or more
apertures 508 in the distal portion 504 that are configured to
deliver one or more fluids (e.g., imaging dye, contrast agent,
oxygenated blood, saline, any combination thereof, or the like) to
a body lumen.
[0086] As illustrated in FIG. 5B, the embolic filter 510 comprises
a frame 524 and a filter medium 526. In its deployed configuration,
the embolic filter 510 opens towards a distal end 516 of the
catheter 502. The device 500 further comprises a pull wire 522 that
is coupled to the frame 524 and can be retracted to deflect or bend
the frame 524 and change the orientation and shape of the embolic
filter 510, in manner similar to that described above with
reference to FIGS. 1B-1D.
[0087] Returning to FIG. 5A, the handle 570 has a wire-engagement
mechanism 574 configured to advance or retract the pull wire 522 by
movement of a first slider 572. The handle 570 also has a
sheath-engagement mechanism 578 configured to advance or retract
the deployment mechanism (e.g. outer sheath) 512 by movement of a
second slider 576.
[0088] FIGS. 6A-6G illustrate embodiments of an embolic protection
device 600. In these embodiments, the embolic protection device 600
comprises a catheter 602 (e.g., a pigtail catheter) having a
proximal end 614, a distal end 616, and a lumen 618 extending from
the proximal end 614 to the distal end 616 along a longitudinal
axis of catheter 602. The lumen 618 may be configured to house a
guidewire 1290 (see FIG. 12A) that is longitudinally movable
through this lumen to coil or straighten the distal portion 604 of
the catheter depending on whether the guidewire is retracted (to
coil the distal portion) or extended (to straighten the distal
portion). In some embodiments, the catheter 602 includes a distal
portion 604 configured to assume a generally arcuate shape being at
least a semi-circle. A side wall of the catheter 602 may optionally
include one or more apertures 608 in the distal portion 604 that
are configured to deliver one or more fluids (e.g., imaging dye,
contrast agent, oxygenated blood, saline, any combination thereof,
or the like) to a body lumen 1292 (see FIG. 12A). The apertures 608
(the plural intended to include embodiments in which the distal
portion 604 includes one aperture 608) are in fluid communication
with the lumen 618. In some embodiments, the distal portion 604 of
the catheter 602 includes one or more radiopaque markers 606. In
some embodiments, the radiopaque markers 606 are wrapped around the
circumference of the distal portion 604 of the catheter 602 and can
have the same or different widths. The embolic protection device
600 further comprises a self-expanding embolic filter 610 defined
by a frame 624 and a filter medium 626, and a deployment mechanism
612 (e.g., a longitudinally retractable outer sheath or a
longitudinally retractable ring). The embolic filter 610 is
disposed around the catheter 602.
[0089] FIG. 6B illustrates the embolic filter 610 deployed in a
self-expanded configuration by retraction of the deployment
mechanism (e.g., outer sheath) 612. The embolic filter 610 includes
a distal opening 640 that is defined by the frame 624, faces the
distal end 616 of the catheter 602, and extends proximally from the
distal opening 640 to a closed proximal end 642. The embolic
protection device 600 further comprises a push wire 622 that is
coupled to the frame 624. The push wire 622 can be advanced, in the
distal direction, to deflect (or bend) and extend the frame 624;
and, in turn, change the configuration of the embolic filter 610
between self-expanded, partially expanded, and fully expanded. In
some embodiments, advancing the push wire 622 may cause the distal
opening 640 of the embolic filter 610 to change orientation, shape,
and/or size to engage at least a portion of the interior body lumen
1292 (see FIG. 12D) wall. FIG. 6B illustrates the push wire 622 in
a retracted, i.e., un-advanced, state with the frame 624 extending
in a distal, longitudinal direction, albeit angled back somewhat
(e.g., less than about 45 degrees) in a lateral direction toward
the proximal end 614. The catheter 602 may be partially surrounded
towards its proximal end 614 by a support catheter 650 that
terminates at a head 652, proximal to the distal portion 604 of the
catheter 602. The support catheter 650 may be made of a thicker,
stiffer material to add rigidity and provide a protective or
supporting layer surrounding the catheter 602.
[0090] FIGS. 6C, 6E, and 6G show front-end views of the embolic
filter 610, as viewed from the distal opening 640, in the
self-expanded, partially expanded, and fully expanded
configurations, respectively. The catheter 602 is removed from
these views for clarity. The frame 624 comprises two sides (624a,
624b) that each extend generally in a first lateral direction away
from the catheter 602/support catheter 650 and then loop back on
opposite sides around the catheter 602/support catheter 650 and
extend generally in the opposite lateral direction before
converging and meeting to form a substantially elliptical (i.e.,
shaped like an ellipse), or alternatively, a substantially ovular
(i.e. shaped like an oval), or circular shape. As shown, the
embolic filter 610 is symmetrical about a plane (identified in the
figure as a dotted line labeled "P"). For ease of discussion, the
embolic filter 610 is referred to as having a left side and a right
side. Elements on the left side of the embolic filter 610 are
mirrored by elements on the right side of the embolic filter
610.
[0091] FIGS. 6D and 6E illustrate the embolic filter 610 in the
partially expanded configuration with the frame 624 deflected
(i.e., bent) by advancement of the push wire 622 in the distal
direction. The frame 624 comprises a movable portion 630 and a
fixed portion 632. The movable portion 630 of the frame 624 can
move, longitudinally, with respect to the catheter 602/support
catheter 650. With respect to the catheter 602/support catheter
650, the movable portion 630 can move, longitudinally, while the
fixed portion 632 cannot. The frame 624 is coupled to the push wire
622 at the movable portion 630. In a convenient embodiment, the
push wire 622 and movable portion 630 are joined by a crimp. In
other embodiments, the push wire 622 and movable portion 630 are
joined by a weld, adhesive, or threads. The frame 624 is attached
to the support catheter 650 (or alternatively, directly to the
catheter 602) by the fixed portion 632. The fixed portion 632 of
the frame 624 may be attached to the catheter 602/support catheter
650 by a weld, an adhesive, or the like.
[0092] Starting at the fixed portion 632, the frame 624 extends in
a distal, longitudinal direction and then bends at an angle with
respect to the longitudinal axis of the catheter 602/support
catheter 650. When the push wire 622 is in its retracted state, the
frame 624 bends at an acute angle and extends in a proximal,
longitudinal direction such that the frame 624 folds onto itself
(see FIG. 6B). Advantageously, in this configuration, the embolic
filter 610 may more effectively retain embolic debris captured
during a procedure. The curvature of the frame 624 adjacent the
movable portion 630 may aid in collapsing the frame 624 in order to
advance the outer sheath 612 over the embolic filter 610.
[0093] FIG. 6E shows the front-end view of the embolic filter 610,
as viewed from the distal opening 640, when the push wire 622 is
advanced and the embolic filter 610 assumes a partially expanded
configuration. The advancing push wire 622 urges the movable
portion 630 forward relative to the catheter 602/support catheter
650. (Shown in FIG. 6D as an arrow pointing away from the support
catheter 650.) This in turn deflects or bends the frame 624
longitudinally in the distal direction and laterally outward. In a
deflected configuration (i.e., when the push wire 622 is advanced),
the distal opening 640 of the embolic filter 610 may be
substantially perpendicular to the longitudinal axis of the
catheter 602/support catheter 650 and may span laterally across the
body lumen 1292 (see FIG. 12D), substantially perpendicular to the
longitudinal axis of the body lumen 1292. In the deflected
configuration, the width, Xbent, across the distal opening 640 is
increased compared to the corresponding dimension in the
non-deflected configuration. By increasing the width, X.sub.bent,
in the bent configuration, the frame 624 defining the distal
opening 640 engages the body lumen 1292.
[0094] FIGS. 6F and 6G illustrate the embolic filter 610 in the
fully expanded configuration with the frame 624 extended by the
further advancement of the push wire 622 in the distal direction.
Moving the push wire 622 further, distally, urges the movable
portion 630 sideways relative to the catheter 602/support catheter
650. This in turn extends the frame 624 radially outward, away from
the catheter 602/support catheter 650. (Shown in FIG. 6G as a left
directional arrow and right directional arrow pointing away from
the support catheter 650.) In some embodiments, in addition to
extending the frame 624 in the radial direction, the advancing push
wire 622 moves the movable portion 630 forward relative to the
catheter 602/support catheter 650; which, in turn, bends the frame
624, further, in the longitudinal direction. In one embodiment, the
movable portion 630 is formed with a curve or bend to aid in
extending the frame 624 in the radial direction.
[0095] In an extended configuration, the width, X.sub.extended,
across the distal opening 640 is increased compared to the
corresponding dimension (X.sub.bent) in the partially expanded
configuration of the embolic filter 610. By increasing the width,
X.sub.extended, in the extended configuration, the frame 624
defining the distal opening 640 engages the body lumen 1292. The
increase in the width across the distal opening 640 between the
partially expanded configuration (X.sub.bent) and the fully
expanded configuration (X.sub.extended) of the embolic filter 610
(and intermediate configurations in between) may represent a range
of filter sizes or diameters, e.g., 25 millimeters (mm) to 40 mm.
The range of filter sizes accommodates variations in patient
vasculature. Advantageously, instead of a one-size-fits-all device
or multiple devices of different sizes, certain embodiments of the
embolic protection device 600 provide a single device that can be
tailored to a particular patient and/or a particular surgical
procedure. For example, a surgeon can expand the embolic filter 610
to a first size and then adjust the embolic filter 610 to a second
size to achieve a better fit within a patient's vasculature.
[0096] In some embodiments, the distal opening 640 of the embolic
filter 610 has a diameter of from about 2 centimeters (cm) to about
6 cm (e.g., from about 2.5 cm to about 4 cm or to about 4.5 cm).
The embolic filter 610 can comprise any suitable size or diameter
to accommodate anatomic variability in patients' body lumens 1292
(see FIG. 12A).
[0097] FIGS. 7A-7C illustrate another embodiment of an embolic
protection device 700 comprising a catheter 702, an embolic filter
710, a movable outer sheath 712, and an actuating mechanism for
operating the embolic filter 710. A portion of the catheter 702 is
slidably received and supported by a fixed inner catheter 750 that
terminates at a head 752. The fixed inner catheter 750 may be made
of a thicker, stiffer material to add rigidity and provide a
protective or supporting layer surrounding the catheter 702. The
embolic filter 710 is disposed around the fixed inner catheter 750
and is configured to self-expand to a radially expanded
configuration, as shown in FIG. 7A, when not confined or restrained
by the outer sheath 712.
[0098] The embolic filter 710 includes a frame 724 and a filter
medium 726. The frame 724 defines a distal opening 740 of the
embolic filter 710 and includes a movable portion 730 for
controlling the size or diameter of the distal opening 740. The
embolic filter 710 extends proximally from the distal opening 740
to a closed proximal end 742. The frame 724 further includes a
fixed portion 732 for attaching the frame 724 to the fixed inner
catheter 750 at a location adjacent to the closed proximal end 742
of the embolic filter 710. In some embodiments, the embolic
protection device 700 is similar to the embolic protection device
600 of FIGS. 6A-6G with the addition of the actuating
mechanism.
[0099] The actuating mechanism comprises an inner catheter 756 and
an outer catheter 758. The inner catheter 756 slides over the fixed
inner catheter 750. The outer catheter 758 slides over the inner
catheter 756. The movement of the inner catheter 756 and outer
catheter 758 relative to the fixed inner catheter 750 controls the
size or diameter of the embolic filter 710, as will be described in
greater detail below.
[0100] The embolic protection device 700 further includes a push
wire 722 coupled to a distal portion 764 of the outer catheter 758.
The push wire 722 is longitudinally movable between a fully
retracted state, a partially advanced (or partially retracted)
state, and a fully advanced state by the outer catheter 758. The
push wire 722 is further coupled to the movable portion 730 of the
frame 724. Moving the outer catheter 758, relative to the fixed
inner catheter 750, translates into moving the push wire 722
between the fully retracted, partially advanced, and fully advanced
states. This in turn urges the movable portion 730, causing the
frame 724 to deflect (or bend) or extend.
[0101] In various embodiments of the embolic protection device 700,
the foregoing device components may be coupled to each other, as
described above, by any number of means and techniques. For
example, in a convenient embodiment, sleeves made from polyether
block amide (PEBAX.RTM.) or other similar biocompatible material
attach the push wire 722 to the distal portion 764 of the outer
catheter 758, attach the top guide 760 to the distal portion 766 of
the inner catheter 756, and attach the bottom guide 762 to the
fixed inner catheter 750. Additionally or alternatively, the device
components may be joined together with a biocompatible
adhesive(s).
[0102] The actuating mechanism further comprises a top guide 760
and a bottom guide 762 for directing the deflection and extension
of the frame 724 so that the distal opening 740 of the embolic
filter 710 faces towards a distal end (or working end) of the
device 220 as it expands. In some embodiments, the top guide 760
and the bottom guide 762 keep the movable portion 730 and the fixed
portion 732 of the frame 724 straight, respectively. The top guide
760 and the bottom guide 762 are arranged at opposite points around
the fixed inner catheter 750 with portions disposed along the fixed
inner catheter 750. The top guide 760 is coupled at one end to a
distal portion 766 of the inner catheter 756. A portion of the top
guide 760, distal to the distal portion 766, is in slidable
engagement with the fixed inner catheter 750 at or otherwise
adjacent to the closed proximal end 742 of the embolic filter 710.
For example, a portion of the top guide 760 slides under the filter
medium 726 along the fixed inner catheter 750 and passes through
the closed proximal end 742 of the embolic filter 710. The bottom
guide 762 is fixedly attached to the fixed inner catheter 750 at or
otherwise adjacent to the closed proximal end 742 of the embolic
filter 710.
[0103] At the distal opening 740 of the embolic filter 710, the top
guide 760 and the bottom guide 762 are movable away from the fixed
inner catheter 750. The top guide 760 slidably receives the movable
portion 730 of the frame 724 and the bottom guide 762 receives the
fixed portion 732. The arrangement causes the top guide 760 and
bottom guide 762 to flare or flex outward away from the fixed inner
catheter 750 (as one moves from the closed proximal end 742 of the
embolic filter 710 to the distal opening 740), thereby, giving the
embolic filter 710 a general funnel-like appearance. The top guide
760 and the bottom guide 762 may also support the filter medium
726, in the longitudinal and lateral directions, between the distal
opening 740 and the closed proximal end 742 of the embolic filter
710. In a convenient embodiment, the top guide 760 and the bottom
guide 762 are hypotubes made from stainless steel,
polyetheretherketone (PEEK), or other biocompatible material.
[0104] FIG. 7A further illustrates the outer sheath 712 fully
retracted over the embolic filter 710 and the embolic filter 710
exposed. The inner catheter 756 and outer catheter 758 are in their
initial positions (labeled "A" in the figure) relative to the fixed
inner catheter 750. With the embolic filter 710 unsheathed, the
movable portion 730 and the fixed portion 732 of the frame 724,
with the top guide 760 and bottom guide 762, flex outwardly away
from the fixed inner catheter 750. This causes the distal opening
740 of the embolic filter 710 to lie at an angle with respect to
the fixed inner catheter 750. For example, the frame 724 and the
fixed inner catheter 750 are at an angle of 45 degrees or less. At
this stage in deployment, the embolic filter 710 is in a
self-expanded configuration with the frame 724 unbent.
[0105] FIG. 7B illustrates the distal opening 740 partial expanded
to a first size or diameter. The inner catheter 756 and outer
catheter 758 are advanced in unison, distally, over the fixed inner
catheter 750. The inner catheter 756 and outer catheter 758 are
moved from their initial positions (labeled "A" in the figure) to
their intermediate positons (labeled "B" in the figure), relative
to the fixed inner catheter 750. The concerted movement of the
inner catheter 756 and the outer catheter 758 advances the push
wire 722 and the top guide 760 together; and, in turn, urges the
movable portion 730 of the frame 724, longitudinally, in the distal
direction (forward direction). This rotates the distal opening 740
of the embolic filter 710 into an orientation substantially
perpendicular to the longitudinal axis of the fixed inner catheter
750 and expands the distal opening 740 to the first size (e.g., a
diameter of about 25 mm).
[0106] FIG. 7C illustrates the distal opening 740 fully expanded to
a second size larger than the first size. In FIG. 7E, the outer
catheter 758 is distally advanced over the inner catheter 756 and
the fixed inner catheter 750. Without the inner catheter 756
moving, the outer catheter 758 moves from its intermediate positon
(labeled "B" in the figure) to its final position (labeled "C" in
the figure), relative to the fixed inner catheter 750. The
continued distal movement of the outer catheter 758 moves the push
wire 722 without moving the top guide 760. A length of the movable
portion 730 of the frame 724 is radially played out from the top
guide 760 (i.e., out of the plane of the page), extending the frame
724 and further expanding the distal opening 740 of the embolic
filter 710 to the second size (e.g., a diameter of about 40
mm).
[0107] FIGS. 8A-8F illustrate embodiments of an embolic protection
device 800 comprising a catheter 802, an embolic filter 810, a
movable outer sheath 812, and a handle 870 for manually operating
the embolic filter 810. In FIG. 8B, the embolic protection device
800 further comprises a push wire 822, a filter frame 824, a filter
media 826, a movable portion 830, a fixed portion 832, a fixed
inner catheter 850, an inner catheter 856, an outer catheter 858, a
top guide 860, and a bottom guide 862 arranged in a configuration
similar to the configuration described above with reference to
FIGS. 7A-7C. For example, the push wire 822 is coupled to a distal
portion 864 of the outer catheter 858, and the top guide 860 is
coupled at one end to a distal portion 866 of the inner catheter
856. In some embodiments, the embolic protection device 800 is
similar to the embolic protection device 700 of FIGS. 7A-7C with
the addition of the handle 870.
[0108] FIG. 8A illustrates the handle 870 having a first slider 872
operable for manually retracting the outer sheath 812 over the
catheter 802 and the embolic filter 810 to deploy the embolic
filter 810 in a self-expanded configuration. The first slider 872
is further used to manually advance the outer sheath 812 over the
catheter 802 and the embolic filter 810, and collapse/recover the
embolic filter 810. The handle 870 further includes a second slider
874 operable for manually increasing and decreasing the size or
diameter of a distal opening 840 of the embolic filter 810. (The
embolic filter 810 extends proximally from the distal opening 840
to a closed proximal end 842.)
[0109] In some embodiments, the catheter 802 is a pigtail-type
catheter as shown in FIG. 8B and described herein. The catheter 802
includes a distal portion 804 configured to assume a generally
arcuate shape being at least a semi-circle. In some embodiments,
the distal portion 804 of the catheter 802 includes one or more
radiopaque markers 806. A side wall of the catheter 802 may
optionally include one or more apertures 808 in the distal portion
804 that are configured to deliver one or more fluids (e.g.,
imaging dye, contrast agent, oxygenated blood, saline, any
combination thereof, or the like) to a body lumen.
[0110] The catheter 802 has a proximal end, a distal end 816, and a
lumen 818 extending between the proximal end and the distal end
816. The lumen 818 may be configured to house a guidewire 1290 (see
FIGS. 12A and 12B) that is longitudinally moveable through this
lumen to coil or straighten the distal portion 804 of the catheter
802 depending on whether the guidewire is retracted (to coil the
distal portion) or extended (to straighten the distal portion). The
apertures 808 and the lumen 818 may in fluid communication with
each other in order to deliver one or more fluids to a body lumen
as described above.
[0111] As shown in the FIG. 8B, an example of the catheter 802 is
partially surrounded towards its proximal end by the fixed inner
catheter 850 that terminates at a head 852, proximal to the distal
portion 804 of the catheter 802. The fixed inner catheter 850 may
be made of a thicker, stiffer material to add rigidity and provide
a protective or supporting layer surrounding the catheter 802.
[0112] FIG. 8C illustrates an example of the handle 870 (with the
handle cover removed for clarity) including a sheath-engagement
mechanism 876 configured to advance or retract the outer sheath 812
by movement of the first slider 872. The outer sheath 812 is joined
to the sheath-engagement mechanism 876. Any number of suitable
means, (e.g., fastener and/or adhesive) or techniques (e.g., sonic
welding, solvent welding, and overmolding) can be used to join the
outer sheath 812 and sheath-engagement mechanism 876.
[0113] The sheath-engagement mechanism 876 is movable within the
handle 870 between a distal, initial position (shown in FIG. 8C)
and a proximal, final position (shown in FIG. 8D). The initial
position of the sheath-engagement mechanism 876 corresponds with
the outer sheath 812 circumferentially disposed around at least a
portion of embolic filter 810 and the embolic filter 810 housed in
the collapsed configuration. The final position of the
sheath-engagement mechanism 876 corresponds with the outer sheath
812 longitudinally retracted over the embolic filter 810 and the
embolic filter 810 deployed in the self-expanded configuration.
[0114] The sheath-engagement mechanism 876 is selectively operable
by the first slider 872. For example, an operator presses down on
the first slider 872 with their thumb to unlock the
sheath-engagement mechanism 876 from the handle 870 in order to
move the sheath-engagement mechanism 876 from the initial position
(shown in FIG. 8C) to the final position (shown in FIG. 8D). The
operator moves the first slider 872, proximally, using their thumb
to retract the outer sheath 812 and expose the embolic filter 810.
To collapse/recover the embolic filter 810, the operator moves the
first slider 872, distally, and advances the outer sheath 812 over
the embolic filter 810.
[0115] The example of the handle 870 shown in FIG. 8C further
includes an engagement mechanism 878 configured to change the size
or diameter of the distal opening 840 of the embolic filter 810 by
movement of the second slider 874. The engagement mechanism 878
comprises a top pull 880 and a bottom pull 882. The top pull 880 is
coupled to a proximal portion of the outer catheter 858 and the
bottom pull 882 is coupled to a proximal portion of the inner
catheter 856 (shown in FIG. 8F).
[0116] The engagement mechanism 878 is movable within the handle
870 between an initial (proximal) position (shown in FIGS. 8C and
8D), an intermediate position (shown in FIG. 8E), and a final
(distal) position (shown in FIG. 8F). The initial position of the
engagement mechanism 878 corresponds with the embolic filter 810 in
the self-expanded configuration with the filter frame 824
undeflected (or unbent). The intermediate position of the
engagement mechanism 878 corresponds with the embolic filter 810 in
a partially expanded configuration with the filter frame 824
deflected (or bent) in the longitudinal direction. The final
position of the engagement mechanism 878 corresponds with the
embolic filter 810 in a fully expanded configuration with the
filter frame 824 extended in the radial direction.
[0117] The engagement mechanism 878 is selectively operable by the
second slider 874. For example, with the engagement mechanism 878
at the initial position (shown in FIG. 8D), a user presses the
second slider 874 down. The applied force causes a projection (not
shown) extending from the second slider 874 to move downward
through a hole (not shown) in the top pull 880 and into a recess
(not shown) in the bottom pull 882.
[0118] In FIG. 8E, with combined reference to FIG. 8B, with the
second slider 874 depressed and engaged with both the top pull 880
and the bottom pull 882, the operator moves the second slider 874,
distally, using their thumb to advance the outer catheter 858 and
the inner catheter (hidden from view) together. The concerted
movement of the outer catheter 858 and the inner catheter moves the
push wire 822 and the top guide 860 together (i.e., moved in
unison). This in turn, advances the movable portion 830,
longitudinally, in the distal direction (forward direction), and
expands the distal opening 840 of the embolic filter 810.
[0119] The distal opening 840 continues to expand with the distal
movement of the second slider 874 until the engagement mechanism
878 reaches the intermediate position shown in FIG. 8E. At the
intermediate position, the distal opening 840 is at a first size
(e.g., a diameter of about 25 mm) and the second slider 874
partially disengages from the engagement mechanism 878. For
example, a spring and ball plunger (not shown), located within the
handle 870, lifts the projection out of the recess in the bottom
pull 882. The second slider 874 disengages from the bottom pull 882
but remains engaged with the top pull 880. It may be convenient to
refer to the engagement between the top pull 880 and the bottom
pull 882 as temporary.
[0120] In FIG. 8F, with combined reference to FIG. 8B, the operator
continues to move the second slider 874, distally, to advance the
outer catheter 858 farther in the distal direction. With the bottom
pull 882 disengaged, the inner catheter 856 and the top guide 860
are fixed in position, while the push wire 822 advances farther in
the distal direction. As a result, a length of the movable portion
830 is radially played out from the top guide 860 (i.e., out of the
plane of the page) and further expands the distal opening 840 of
the embolic filter 810 to a next size (e.g., a diameter of about 30
mm). The distal opening 840 expands to its maximum size (e.g., a
diameter of about 40 mm) when the engagement mechanism 878 is at
the final position as shown in FIG. 8F. To recover the embolic
filter 810, the process described above with reference to FIGS.
8C-8F is carried out in reverse.
[0121] In some embodiments, a wire of an embolic protection device
as described herein, e.g., the pull wire 122 of the embolic
protection device 100 of FIG. 1B or the push wire 622 of the
embolic protection device 600 of FIG. 6B, comprises a metal
material, for example, stainless steel. Alternatively, the wire may
comprise a plastic material or other suitable material. In some
embodiments, the wire is stainless steel coated in
polytetrafluoroethylene (PTFE). In the case of the wire being a
pull wire, similar to the pull wire 122 of FIG. 1B, the pull wire
is flexible but may have sufficient rigidity to deflect (or bend) a
frame of an embolic filter in a proximal direction when the pull
wire is retracted in a manner similar to that described above with
reference to FIGS. 1C and 1D. In the case of the wire being a push
wire, similar to the push wire 622 of FIG. 6B, the push wire is
flexible but may have sufficient rigidity to deflect/bend a frame
of an embolic filter in a distal direction when the pull wire is
advanced; and to extend the frame in a radial direction when the
pull wire is father advanced in a manner similar to that described
above with reference to FIGS. 6D-6F.
[0122] In some embodiments, a filter medium (e.g., the filter
medium 126 of FIG. 1A or the filter medium 626 of FIG. 6B)
comprises a braided mesh, for example braided nitinol mesh. In some
embodiments, the filter medium comprises a porous membrane, for
example a semi-permeable polyurethane membrane. In other
embodiments, the filter medium has a pore size of from about 100
microns to about 150 microns (e.g., about 125 microns).
[0123] In some embodiments, an embolic filter (e.g., the embolic
filter 110 of FIG. lB or the embolic filter 610 of FIG. 6B)
comprises an anti-thrombogenic coating (e.g., a heparin coating or
other coating comprising a thrombin or platelet inhibitor) to
advantageously reduce thrombogenicity.
[0124] The embolic filter is configured to self-expand to a
radially expanded configuration illustrated in, for example FIGS.
1B and 1C, and FIGS. 6B and 6C, when not confined or restrained by
an deployment device, such as the outer sheath 112 of FIG. 1A or
the outer sheath 612 of FIG. 6A.
[0125] In some embodiments wherein the deployment mechanism
comprises an outer sheath (e.g., the movable outer sheath 112 of
FIG. 1A or the movable outer sheath 612 of FIG. 6A), the outer
sheath is configured to be circumferentially disposed around at
least a portion of a catheter and a embolic filter (e.g., the
catheter 102 and the embolic filter 110 of FIG. 1A; or the catheter
602 and the embolic filter 610 of FIG. 6A). The outer sheath is
configured to contain or house the embolic filter in a collapsed
configuration. The outer sheath is longitudinally movable with
respect to the catheter, and can be longitudinally retracted (i.e.,
moved longitudinally in a proximal direction) to deploy the embolic
filter and longitudinally advanced (i.e., moved longitudinally in a
distal direction) to recapture the embolic filter and any embolic
material collected by the embolic filter. The embolic filter is
configured to self-expand upon longitudinal retraction of the outer
sheath.
[0126] In some embodiments, an embolic filter of an embolic
protection device as described herein (e.g., the embolic filter 110
of FIG. 1A and the embolic filter 610 of FIG. 6A) is configured to
at least partially collapse upon longitudinal extension of an outer
sheath (e.g., the outer sheath 112 of FIG. 1A and the outer sheath
612 of FIG. 6A). In these embodiments, a distal opening of the
embolic filter (e.g., the distal opening 140 of FIG. lB and the
distal opening 640 of FIG. 6B) assumes a substantially closed
configuration thereby sequestering or substantially sequestering
the filtered material.
[0127] In some embodiments, a catheter of an embolic protection
device as described herein (e.g., the catheter 102 of FIG. 1A and
the catheter 602 of FIG. 6A) may comprise a flexible material so as
to be maneuverable within a body lumen (e.g., the body lumen 992 of
FIG. 9A and the body lumen 1292 of FIG. 12A) as further described
herein. For example, in some embodiments, the catheter comprises a
metal or metal alloy. In other embodiments, the catheter comprises
a polymer (e.g., polyurethane, silicone, latex,
polytetrafluoroethylene (PTFE), a plastic material, any combination
thereof, or the like). In some embodiments, the catheter comprises
a metal-reinforced plastic (e.g., including nitinol, stainless
steel, and the like). Other materials are also possible. In some
embodiments, the catheter is substantially free of latex (natural
or synthetic), which may cause allergic reactions in some patients.
In some embodiments, the catheter comprises braid-reinforced tubing
to advantageously increase the strength of the catheter. In some
embodiments, the catheter comprises a braided catheter shaft
including a layer of braided wire between two layers of catheter
tubing, which may increase the strength of the catheter. In some
embodiments, the catheter does not include a braided layer, which
may increase the flexibility of the catheter. In some embodiments,
the catheter comprises a lubricious coating, for example a coating
having a low friction coefficient, to advantageously allow for
smoother navigation through tortuous vasculature. In some
embodiments, the catheter coating has anti-thrombotic properties to
advantageously inhibit thrombus formation. In some embodiments, the
catheter has a size (i.e., outside diameter) between about 3 French
and about 5 French (between about 2 mm and about 3 mm). Other sizes
are also possible, for example depending on the size of the target
body lumen of a particular patient. In some embodiments, the
catheter has a length between about 65 centimeters (cm) and about
135 cm. Other lengths are also possible, for example to allow for
insertion of the catheter in the femoral, radial, brachial, or
subclavian artery. The catheter can be manufactured, for example,
by extrusion, injection molding, or another suitable process.
[0128] In some embodiments, an embolic protection device as
described herein may include one or more radiopaque marker bands
located at a distal portion of a catheter. For example, the embolic
protection device 100 of FIGS. 1A and 1B with the radiopaque
markers 106 located at the distal portion 104 of the catheter 102.
As another example, the embolic protection device 600 of FIGS. 6A
and 6B with the radiopaque markers 606 located at the distal
portion 604 of the catheter 602. When the distal portion assumes a
generally arcuate shape, the circumferential radiopaque marker
bands may be visualized to confirm that the distal portion is
generally arcuate. In some embodiments, the radiopaque marker bands
are located so that when the distal portion assumes its generally
arcuate configuration, the marker bands are at the distal most
point of the catheter, i.e., actually beyond a distal end of the
catheter (e.g., beyond the distal end 116 of the catheter 102 shown
in FIGS. 1A and 1B; or beyond the distal end 616 of the catheter
602 shown in FIGS. 6A and 6B).
[0129] The radiopaque markers comprise a radiopaque material, for
example platinum, tantalum, tungsten, palladium, and/or iridium.
Other radiopaque materials are also possible. In some embodiments,
a material may be considered radiopaque, for example, if the
average atomic number is greater than 24 or if the density is
greater than about 9.9 g/cm.sup.3. In some embodiments a distal
portion of the catheter (e.g., the distal portion 104 of the
catheter 102 of FIGS. 1A and 1B; and the distal portion 604 of the
catheter 602 of FIGS. 6A and 6B) may be infused with a radiopaque
material so that the entire distal portion is visible using imaging
techniques.
[0130] In some embodiments, an outer sheath of an embolic
protection device as described herein comprises a hollow tube
configured to circumferentially surround at least a portion of the
catheter. For example, the outer sheath 112 of the embolic
protection device 100 of FIGS. 1A-1F or the outer sheath 612 of the
embolic protection device 600 of FIGS. 6A-6G. The outer sheath is
longitudinally movable with respect to the catheter and is
configured to at least partially contain or house the embolic
filter in a collapsed configuration when circumferentially
surrounding the embolic filter, for example, as shown in FIG. 1A
and FIG. 6A. The outer sheath is longitudinally proximally
retractable to release the embolic filter to the expanded, open
configuration when not contained by the outer sheath.
[0131] In some embodiments, the outer sheath extends proximally to
a proximal end of the catheter (e.g., the proximal end 114 of the
catheter 102 shown in FIG. 1A or the proximal end 614 of the
catheter 602 shown in FIG. 6A) so that the user can grasp and
manipulate the outer sheath directly. In some embodiments, the
outer sheath extends proximally over only a portion of the
catheter, and a secondary device (e.g., a push-rod such as found in
stent deployment systems) is coupled to the outer sheath (e.g., to
the proximal end of the outer sheath) to allow for indirect
manipulation of the outer sheath. Manipulation of the outer sheath
may be mechanical, electronic, manual, combinations thereof, and
the like.
[0132] In some embodiments, an embolic protection device as
described herein may have a longitudinally extending groove (not
shown) along its outer surface. For example, the embolic protection
device 100 of FIG. 1B includes a longitudinally extending groove
along the catheter 102, along the support catheter 150, or along
the deployment mechanism (e.g. outer sheath) 112. In another
example, the embolic protection device 600 of FIG. 6B includes a
longitudinally extending groove along the catheter 602, along the
support catheter 650, or along the deployment mechanism/outer
sheath 612. In some embodiments, the groove may extend
substantially from the proximal end to the distal end of the
embolic protection device. The groove may be useful for guiding
another catheter device alongside the embolic protection device.
For example, the groove may be useful for guiding a valve delivery
device alongside and beyond the distal end of the embolic
protection device. Advantageously, the second device may be tracked
along the groove and pass beyond the embolic protection device
while the embolic filter is deployed as shown, for example, in FIG.
13A.
[0133] A device according to the disclosure herein can comprise
some or all of the features of the embolic protection device 100,
200, 300, 400, 500, 600, 700, and 800 as shown in FIGS. 1A-1F;
FIGS. 2A and 2B; FIGS. 3A-3D; FIGS. 4A-4C; FIGS. 5A and 5B; FIGS.
6A-6G; FIGS. 7A-7C; and FIGS. 8A-8F; and is described herein in
various combinations.
III. METHODS OF CAPTURING EMBOLIC DEBRIS
[0134] Another aspect of the present invention provides a method
900 of capturing embolic debris during a closed-heart medical
procedure (e.g., an aortic valve replacement procedure), as
illustrated in a stepwise fashion in FIGS. 9A-9E, using an embolic
protection device of the present invention (e.g., the embolic
protection device 100, 200, 300, 400, or 500 as described
herein).
[0135] Referring to FIG. 9A, in one embodiment, a guidewire 990 is
percutaneously inserted into a body lumen 992 of a patient, for
example a femoral, radial, brachial, or subclavian artery, and
navigated to the desired anatomical location, for example, the
ascending aorta. The guidewire 990 can be a J-tipped wire having a
diameter of about 0.035 in. (approx. 0.089 cm). Other types and
dimensions of guidewires 990 useful for this method are also
possible.
[0136] In some embodiments, the proximal end of the guidewire 990
is inserted into the opening at the distal end 116 of the catheter
102. When the guidewire 990 is in the lumen 118 of the catheter 102
at the distal portion 104 of the catheter 102, the distal portion
104 of the catheter is straightened or assumes the curvature of the
guidewire 990. The distal end 116 of the catheter 102 is inserted
into the body lumen 992 by tracking the lumen 118 of the catheter
102 over the guidewire 990, as shown in FIG. 9A. The outer diameter
of the guidewire 990 is smaller than the inner diameter of the
embolic protection device 100 such that the embolic protection
device 100 may be tracked over the guidewire 990. The inner surface
of the lumen 118 and/or the outer surface of the guidewire 990 may
include a lubricious coating to reduce friction during tracking.
The guidewire 990 keeps the distal portion 104 of the catheter 102
substantially straight (e.g., from being in the generally arcuate
state) as the catheter 102 is inserted into and navigated within
the patient's body.
[0137] The radiopaque marker(s) 106 are used to visualize and
position the distal portion 104 of the catheter 102 during
tracking. The guidewire 990 is retracted, i.e., moved
longitudinally in a proximal direction, a sufficient distance to
allow the distal portion 104 of the catheter 102 to assume the
generally arcuate shape, as shown in FIG. 9B. The distal portion
104 of the catheter 102 is positioned at the desired anatomical
landmark, for example, the lower border of the noncoronary cusp of
the aortic valve. The radiopaque marker(s) 106 are on the
distal-most section of the distal portion 104 when the distal
portion 104 assumes its generally arcuate shape. In some
embodiments the distal portion 104 of the catheter 102 may be
infused with a radiopaque material so that the entire distal
portion 104 is visible using imaging techniques.
[0138] In some embodiments of the method, the proximal end 114 of
the catheter 102 is connected to a contrast material injector, and
contrast material is injected into the lumen 118 of the catheter
102, for example to visualize the anatomy around the device 100.
The contrast material exits the catheter 102 lumen 118 through the
opening at the distal end 116 of the catheter 102 and/or through
one or more apertures 108 in the side wall of the catheter 102.
Injecting contrast material can aid in visualizing and positioning
the catheter 102.
[0139] In some embodiments, a second guidewire is percutaneously
inserted into a second body lumen, for example the other femoral
artery, and a second catheter is tracked over the second guidewire.
The second catheter can carry a medical device or instrument, for
example, a replacement valve, a valve repair system, or a radio
frequency ablation system. Once the second catheter and associated
device or instrument are properly positioned, the outer sheath 112
of the catheter 102 is longitudinally proximally retracted,
allowing the embolic filter 110 to assume the expanded, deployed
configuration, as shown in FIG. 9C.
[0140] Next, the pull wire 122 can be retracted to bend the frame
124 of the embolic filter 110. The pull wire 122 bends the frame
124 in a proximal longitudinal direction and laterally outward. In
a fully bent configuration (i.e., with pull wire fully retracted),
as shown in FIGS. 9D and 9E, the distal opening 140 of the embolic
filter 110 may be substantially perpendicular to the catheter 102
and may span laterally across the body lumen 992, substantially
perpendicular to the longitudinal axis of the body lumen 992. The
fully bent configuration may engage the body lumen 992, thereby
capturing embolic debris 994 in the embolic filter 110 without
allowing embolic debris to travel around the outside of the embolic
filter 110. The second guidewire and/or the second catheter can
also be positioned after the embolic filter 110 is deployed. The
distal opening 140 of the embolic filter 110 is located in the
ascending aorta so that blood flows through the filter before
flowing into the carotid arteries or descending aorta. In some
embodiments, when the embolic filter 110 is deployed, the catheter
102 rests against the interior lumen wall, thereby stabilizing the
catheter 102. The procedure can then be performed, and embolic
debris dislodged or otherwise in the blood stream during the
procedure is captured by the embolic filter 110.
[0141] After the procedure, the pull wire 122 is advanced and the
outer sheath 112 is longitudinally distally advanced to recapture
the embolic filter 110, returning the frame to the unbent
configuration and returning the embolic filter 110 to the collapsed
configuration and capturing any embolic debris 994 (see FIG. 9E)
contained within the embolic filter 110. The second catheter and
catheter 102 can then be withdrawn from the patient's body. The
catheter 102 can be retracted over the guidewire 990 or without
straightening the distal portion 104 of the catheter 102 because
the arcuate shape of the distal portion 104 is atraumatic to the
blood vessels.
[0142] In some embodiments, the procedure performed is a cardiac
valve replacement procedure, for example an aortic valve
replacement procedure. The embolic protection device 100 is
introduced into the patient and navigated to the aortic valve as
described herein and shown in FIGS. 9A-9E. The radiopaque marker(s)
106 assist in delineating the lower border of the noncoronary cusp
to assist in proper positioning of a percutaneously implanted
replacement aortic valve. Once the catheter 102 is positioned, a
second guidewire can be percutaneously inserted into a second body
lumen and navigated to the level of the ascending aorta or left
ventricle. A balloon can be tracked over the second guidewire to
the aortic valve. The outer sheath 112 is then retracted to deploy
the embolic filter 110 and the pull wire 122 is retracted to bend
the frame 124 to a bent configuration. Balloon inflation of the
valve can then be performed, and the embolic filter 110 captures
embolic debris 994 dislodged during the procedure or otherwise in
the blood stream. After balloon pre-dilation, the pull wire 122 is
advanced and the outer sheath 112 is advanced to recapture the
embolic filter 110 and any embolic debris 994 contained within the
embolic filter 110. The balloon is removed, and a second catheter
carrying a valvular prosthesis is advanced to the level of the
ascending aorta by tracking the catheter over the second guidewire.
The outer sheath 112 is again retracted to redeploy the embolic
filter 110 and the pull wire 122 is again retracted. The radiopaque
marker(s) 106 allow the user to properly position the valve
prosthesis, for example about 4 mm to about 6 mm below the lower
border of the noncoronary cusp. After the procedure is completed,
the pull wire 122 is advanced and the outer sheath 112 is advanced
to recapture the embolic filter 110 and any captured embolic debris
994, and the catheters are removed from the body. In some
embodiments, the second catheter can be removed prior to
recapturing the embolic filter 110 and embolic debris 994.
[0143] In some embodiments, the procedure is a cardiac valve repair
procedure. The method described herein can also be adapted for a
mitral valve repair or replacement procedure. In some embodiments,
the procedure is a radio frequency ablation procedure, for example
to treat atrial fibrillation. In some embodiments, the procedure is
a catheterization procedure or structural heart procedure.
[0144] In some embodiments, a method of capturing embolic debris as
described herein may include inserting a second catheter device
through the same vessel as the embolic protection device. The
second catheter device may be inserted after the embolic protection
device and may be tracked along a longitudinal groove in the outer
surface of the embolic protection device. For example, a valve
delivery catheter device may be guided alongside the embolic
protection device and beyond the distal end of the embolic
protection device by tracking the valve delivery device along the
groove. Advantageously, the second device may be tracked along the
groove and pass beyond the embolic protection device while the
embolic filter is deployed as shown, for example, in FIG. 13A.
[0145] FIG. 10 illustrates another embodiment of a method 1000 of
deflecting and capturing embolic debris during a medical procedure
using an embolic protection device 1001. The embolic protection
device 1001 is similar to the embolic protection device 300 that is
described in FIGS. 3A-3D, in that it has an intermediate tube 1030.
The embolic protection device 1001 further comprises an embolic
filter 1010 that is movably coupled to a catheter 1002 by way of a
frame 1024 and is longitudinally movable with respect to the
catheter 1002. As shown in the figure, the catheter 1002 is at
least partially surrounded by a support catheter 1050 that
terminates at a head 1052, proximal to a distal portion 1004 of the
catheter 1002. The embolic filter 1010 is coupled to the
intermediate tube 1030 that at least partially circumferentially
surrounds the support catheter 1050. The intermediate tube 1030 is
longitudinally movable with respect to the catheter 1002.
[0146] The embolic protection device 1001 further comprises an
outer sheath (not shown) configured to at least partially
circumferentially surround both the catheter 1002/support catheter
1050 and the intermediate tube 1030. The intermediate tube 1030 and
the outer sheath can be moved simultaneously and independently. The
longitudinal position of the embolic filter 1010 with respect to
the catheter 1002 can be adjusted while the embolic filter 1010 is
in the collapsed configuration or in a deployed or partially
deployed, expanded configuration.
[0147] The method 1000 includes capturing emboli using the embolic
protection device 1001 in a manner similar to the method 900
described above with reference to FIGS. 9A-9E. For example, a
distal end 1016 of the catheter 1002 is inserted into a body lumen
1080 of a patient by tracking a lumen 1018 of the catheter 1002
over a guidewire, which was previously percutaneously inserted into
the body lumen 1080. The guidewire keeps a distal portion 1004 of
the catheter 1002 substantially straight (e.g., from being in the
generally arcuate state) as the catheter 1002 is inserted into and
navigated within the patient's body. The radiopaque marker 1006 is
used to visualize and position the distal portion 1004 of the
catheter 1002 during tracking. Visualization may also be
accomplished by perfusing imaging dye or contrast agent through
apertures 1008 in the distal portion 1004 of the catheter 1002.
Once positioned at the desired anatomical landmark (e.g., the lower
border of the noncoronary cusp of the aortic valve), the guidewire
is retracted a sufficient distance to allow the distal portion 1004
of the catheter 1002 to assume the generally arcuate shape, as
shown in FIG. 10.
[0148] The longitudinal position of the embolic filter 1010 within
the body lumen 1080 can be adjusted by simultaneously moving the
intermediate tube 1030 and the outer sheath. When the embolic
filter 1010 is in the desired longitudinal position within the body
lumen 1080, the intermediate tube 1030 is held stationary while the
outer sheath is retracted to deploy the embolic filter 1010. Next,
the pull wire 1022 is retracted to bend the frame 1024 and open the
embolic filter 1010 to capture emboli.
[0149] The method 1000 further includes deflecting emboli. The
embolic protection device 1001 also comprises a deflector 1060
similar to that shown in FIGS. 4A-C. Once the embolic protection
device 1001 is in position (as described above), the deflector 1060
is deployed from the outer sheath to cover the brachiocephalic and
left common carotid artery. In some patients, the deflector 1060
might also cover the left subclavian artery. During a subsequent
medical procedure, the deflector 1060 can prevent emboli from
entering the carotid arteries, and the embolic filter 1010 can
capture emboli deflected by the deflector 1060 before it travels to
other parts of the patient's body. The method 1000 can also be
performed with various other embolic protection devices, for
example as described herein, and deflector devices that may vary in
configuration and how they are introduced into the body and
navigated to the aortic arch.
[0150] FIG. 11 illustrates another embodiment of a method 1100 of
deflecting and capturing embolic debris. An embolic protection
device 1101 comprises a catheter 1102 (e.g., a pigtail catheter)
with a radiopaque marker 1106 and an embolic filter 1110 disposed
around the catheter 1102 similar to the embolic filter 110
illustrated in FIGS. 1A-1F and described herein. As shown in the
figure, the catheter 1102 is partially surrounded by a support
catheter 1150 that terminates at a head 1152, proximal to a distal
portion 1104 of the catheter 1102.
[0151] The method 1100 includes capturing emboli using the embolic
protection device 1101 in a manner similar to the method 900
described above with reference to FIGS. 9A-9E. For example, a
distal end 1116 of the catheter 1102 is inserted into a body lumen
1180 of a patient by tracking a lumen 1118 of the catheter 1102
over a guidewire, which was previously percutaneously inserted into
the body lumen 1180. The guidewire keeps a distal portion 1104 of
the catheter 1102 substantially straight (e.g., from being in the
generally arcuate state) as the catheter 1102 is inserted into and
navigated within the patient's body. The radiopaque marker 1106 is
used to visualize and position the distal portion 1104 of the
catheter 1102 during tracking. Visualization may also be
accomplished by perfusing imaging dye or contrast agent through
apertures 1108 in the distal portion 1104 of the catheter 1102.
[0152] Once positioned at the desired anatomical landmark (e.g.,
the lower border of the noncoronary cusp of the aortic valve), the
guidewire is retracted a sufficient distance to allow the distal
portion 1104 of the catheter 1102 to assume the generally arcuate
shape, as shown in FIG. 11. An outer sheath (not shown) of the
catheter 1102 is longitudinally, proximally retracted, allowing the
embolic filter 1110 to assume the expanded, deployed configuration,
as shown in FIG. 11. Next, the pull wire 1122 is retracted to bend
the frame 1124 and open the embolic filter 1110 to capture
emboli.
[0153] The method 1100 further includes deflecting emboli with a
deflector 1160. As shown, the deflector 1160 is mounted to a shaft
1162 and contained in an introducer 1168 during insertion. The
introducer 1168 is introduced into the patient's body through the
artery (e.g., right radial artery) and navigated to the aortic arch
via the brachiocephalic artery. Once in position, the deflector
1160 is deployed from the introducer 1168 and pulled back to cover
the brachiocephalic and left common carotid artery. In some
patients, the deflector 1160 might also cover the left subclavian
artery. In some embodiments, the deflector 1160 can be introduced
and deployed before the catheter 1102 is navigated to the aortic
arch. During a subsequent medical procedure, the deflector 1160 can
prevent emboli from entering the carotid arteries, and the embolic
filter 1110 can capture emboli deflected by the deflector 1160
before it travels to other parts of the patient's body. The method
1100 can also be performed with various other embolic protection
devices, for example as described herein, and deflector devices
that may vary in configuration and how they are introduced into the
body and navigated to the aortic arch.
[0154] Another aspect of the present invention provides a method of
capturing embolic debris during a closed-heart procedure,
comprising inserting a distal end of a embolic protection device
into a body lumen, the embolic protection device comprising a
catheter having a proximal end, a distal end, and a lumen extending
from the proximal end of the catheter to the distal end of the
catheter, wherein the lumen is configured to house a guidewire, and
a distal portion of the catheter that assumes a generally arcuate
shape being at least a semi-circle when the guidewire is at least
partially longitudinally retracted; a self-expanding embolic filter
that is disposed around the catheter proximal to the distal
portion, wherein the embolic filter comprises a frame, and the
frame defines an opening of the embolic filter; a deployment
mechanism that is disposed around at least a portion of the
catheter, wherein the deployment mechanism is longitudinally
movable with respect to the catheter, the deployment mechanism is
configured to contain the embolic filter in a collapsed
configuration, and the embolic filter is configured to self-expand
upon longitudinal retraction of the deployment mechanism; and a
pull wire coupled to the frame of the embolic filter, wherein the
wire is longitudinally movable, and when longitudinally retracted,
bends the frame longitudinally toward the proximal end of the
catheter and laterally outward from the catheter, such that the
opening of the embolic filter generally faces the distal end of the
catheter. The method further includes tracking the lumen of the
catheter over the guidewire that is percutaneously inserted into
the body lumen.
[0155] Some embodiments further comprise at least partially
longitudinally retracting the guidewire from the lumen of the
catheter, so that the distal portion of the catheter assumes a
generally arcuate shape being at least a semi-circle.
[0156] In some embodiments, the distal portion of the catheter
comprises a radiopaque marker; and the method further comprises
positioning the catheter by visualizing the radiopaque marker using
an imaging technique.
[0157] Some embodiments comprise at least partially longitudinally
retracting the deployment mechanism and allowing the self-expanding
embolic filter to assume an expanded, deployed configuration.
[0158] Some embodiments comprise longitudinally retracting the
wire, thereby bending the frame longitudinally toward the proximal
end of the catheter and laterally outward from the catheter,
wherein the opening defined by the frame substantially spans the
body lumen.
[0159] Some embodiments comprise longitudinally retracting the wire
to a proximal position, thereby bending the frame so that the
opening of the filter defined by the frame is substantially
perpendicular to the longitudinal direction of the catheter,
wherein the opening defined by the frame substantially spans the
body lumen.
[0160] In some embodiments, the embolic filter is movably coupled
to the catheter and is longitudinally moveable with respect to the
catheter, and the method comprises longitudinally moving the
embolic filter with respect to the catheter.
[0161] In some embodiments, the embolic protection device comprises
a self-expanding deflector coupled to the catheter proximal to the
distal portion, and the method comprises deploying the
self-expanding deflector to direct embolic debris toward the
embolic filter.
[0162] In some embodiments, the deployment mechanism is a sheath
that is circumferentially disposed around at least a portion of the
catheter.
[0163] In some embodiments, the distal portion of the catheter
comprises one or more apertures that communicate with the lumen of
the catheter; the method further comprising perfusing a fluid into
the body lumen through the one or more apertures.
[0164] In some embodiments, the embolic protection device comprises
a longitudinal groove along an outer surface of the embolic
protection device; the method further comprising inserting a second
catheter device alongside the embolic protection device by tracking
the second catheter device along the groove.
[0165] In some embodiments, the second catheter device is advanced
past the embolic filter of the embolic protection device while the
embolic filter is in a deployed configuration.
[0166] Another aspect of the present invention provides a method of
capturing embolic debris during a closed-heart procedure, the
method comprising inserting a distal end of a embolic protection
device into a body lumen, the embolic protection device comprising
a catheter having a proximal end, a distal end, and a lumen
extending from the proximal end of the catheter to the distal end
of the catheter, wherein the lumen is configured to house a
guidewire, and a distal portion of the catheter assumes a generally
arcuate shape being at least a semi-circle when the guidewire is at
least partially longitudinally retracted; a self-expanding embolic
filter that is disposed around the catheter proximal to the distal
portion, wherein the embolic filter comprises a frame, and the
frame defines an opening of the embolic filter; a deployment
mechanism that is disposed around at least a portion of the
catheter, wherein the deployment mechanism is longitudinally
movable with respect to the catheter, the deployment mechanism is
configured to contain the embolic filter in a collapsed
configuration, and the embolic filter is configured to self-expand
upon longitudinal retraction of the deployment mechanism; a wire
coupled to the frame of the self-expanding filter, wherein the wire
is longitudinally movable, and when longitudinally retracted, bends
the frame longitudinally toward the proximal end of the catheter
and laterally outward from the catheter, such that the opening of
the embolic filter generally faces the distal end of the
catheter
[0167] The method further includes tracking a lumen of the catheter
over a guidewire that is percutaneously inserted into the body
lumen and at least partially longitudinally retracting the
guidewire from the lumen of the catheter, so that the distal
portion of the catheter assumes a generally arcuate shape being at
least a semi-circle upon retracting the guidewire from the distal
portion of the catheter. The method further includes longitudinally
retracting the deployment mechanism and deploying the
self-expanding embolic filter. The method further includes
longitudinally retracting the wire and bending the frame of the
embolic filter longitudinally toward the proximal end of the
catheter and laterally outward from the catheter.
[0168] Yet another aspect of the present invention provides a
method 1200 of capturing embolic debris during a closed-heart
medical procedure (e.g., an aortic valve replacement procedure), as
illustrated in a stepwise fashion in FIGS. 12A-12D, using an
embolic protection device of the present invention (e.g., the
embolic protection device 600, 700, or 800 as described
herein).
[0169] Referring to FIG. 12A, in one embodiment, a guidewire 1290
is percutaneously inserted into a body lumen 1292 of a patient, for
example a femoral, radial, brachial, or subclavian artery, and
navigated to the desired anatomical location, for example, the
ascending aorta. The guidewire 1290 can be a J-tipped wire having a
diameter of about 0.035 in. (approx. 0.089 cm). Other types and
dimensions of guidewires useful for this method are also
possible.
[0170] In other embodiments, the proximal end of the guidewire 1290
is inserted into the opening at the distal end 616 of the catheter
602. When the guidewire 1290 is in the lumen 618 of the catheter
602 at the distal portion 604 of the catheter 602, the distal
portion 604 of the catheter is straightened or assumes the
curvature of the guidewire 1290. The distal end 616 of the catheter
602 is inserted into the body lumen 1292 by tracking the lumen 618
of the catheter 602 over the guidewire 1290, as shown in FIG. 12A.
The outer diameter of the guidewire 1290 is smaller than the inner
diameter of the embolic protection device 600 such that the embolic
protection device 600 may be tracked over the guidewire 1290. The
inner surface of the lumen 618 and/or the outer surface of the
guidewire 1290 may include a lubricious coating to reduce friction
during tracking. The guidewire 1290 keeps the distal portion 604 of
the catheter 602 substantially straight (e.g., from being in the
generally arcuate state) as the catheter 602 is inserted into and
navigated within the patient's body.
[0171] The radiopaque marker(s) 606 are used to visualize and
position the distal portion 604 of the catheter 602 during
tracking. The guidewire 1290 is retracted, i.e., moved
longitudinally in a proximal direction, a sufficient distance to
allow the distal portion 604 of the catheter 602 to assume the
generally arcuate shape, as shown in FIG. 12B. The distal portion
604 of the catheter 602 is positioned at the desired anatomical
landmark, for example, the lower border of the noncoronary cusp of
the aortic valve. The radiopaque marker(s) 606 are on the
distal-most section of the distal portion 604 when the distal
portion 604 assumes its generally arcuate shape. In some
embodiments, the distal portion 604 of the catheter 602 may be
infused with a radiopaque material so that the entire distal
portion 604 is visible using imaging techniques.
[0172] In other embodiments of the method, the proximal end 614 of
the catheter 602 is connected to a contrast material injector, and
contrast material is injected into the lumen 618 of the catheter
602, for example to visualize the anatomy around the embolic
protection device 600. The contrast material exits the lumen 618
through the opening at the distal end 616 of the catheter 602
and/or through one or more apertures 608 in the side wall of the
catheter 602. Injecting contrast material can aid in visualizing
and positioning the catheter 602.
[0173] In other embodiments, a second guidewire is percutaneously
inserted into a second body lumen, for example the other femoral
artery, and a second catheter is tracked over the second guidewire.
The second catheter can carry a medical device or instrument, for
example, a replacement valve, a valve repair system, or a radio
frequency ablation system. Once the second catheter and associated
device or instrument are properly positioned, the outer sheath 612
is longitudinally retracted in the proximal direction, allowing the
embolic filter 610 to assume the self-expanded, deployed
configuration, as shown in FIG. 12C.
[0174] Next, the push wire 622 can be advanced to bend the filter
frame of the embolic filter 610. The push wire and the filter frame
are not shown in FIGS. 12A-12D, but can be seen in FIGS. 6B-6F as
the push wire 622 and the frame 624, respectively. The push wire
bends the filter frame in a distal longitudinal direction and
laterally outward. In the bent configuration (i.e., with the pull
wire advanced in the distal direction), as shown in FIG. 12D, the
distal opening 640 of the embolic filter 610 may be substantially
perpendicular to the catheter 602 and may span laterally across the
body lumen 1292, substantially perpendicular to the longitudinal
axis of the body lumen 1292. To accommodate the size of the body
lumen 1292, the push wire can be advanced farther to extend the
frame in the radial direction and further expand the embolic filter
610.
[0175] The bent configuration may engage the body lumen 1292,
thereby capturing embolic debris 1294 in the embolic filter 610
without allowing embolic debris to travel around the outside of the
embolic filter 610. The second guidewire and/or the second catheter
can also be positioned after the embolic filter 610 is deployed.
The distal opening 640 of the embolic filter 610 is located in the
ascending aorta so that blood flows through the embolic filter 610
before flowing into the carotid arteries or descending aorta. In
some embodiments, when the embolic filter 610 is deployed, the
catheter 602 rests against the interior lumen wall, thereby
stabilizing the catheter 602. The procedure can then be performed
and embolic debris 1294 dislodged or otherwise in the blood stream
during the procedure is captured by the embolic filter 610.
[0176] After the procedure, the push wire 622 is retracted and the
outer sheath 612 is longitudinally and distally advanced to
recapture the embolic filter 610, returning the filter frame to the
unbent configuration and returning the embolic filter 610 to the
collapsed configuration. And in turn capturing any embolic debris
1294 (see FIG. 12D) contained within the embolic filter 610. The
second catheter and catheter 602 can then be withdrawn from the
patient's body. The catheter 602 can be retracted over the
guidewire 1290 or without straightening the distal portion 604 of
the catheter 602 because the arcuate shape of the distal portion
604 is atraumatic to the blood vessels.
[0177] In other embodiments, the procedure performed is a cardiac
valve replacement procedure, for example an aortic valve
replacement procedure. The embolic protection device 600 is
introduced into the patient and navigated to the aortic valve as
described herein and shown in FIGS. 12A-12D. The radiopaque
marker(s) 606 assist in delineating the lower border of the
noncoronary cusp to assist in proper positioning of a
percutaneously implanted replacement aortic valve. Once the
catheter 602 is positioned, a second guidewire can be
percutaneously inserted into a second body lumen and navigated to
the level of the ascending aorta or left ventricle. A balloon can
be tracked over the second guidewire to the aortic valve. The outer
sheath 612 is then retracted to deploy the embolic filter 610 and
the push wire 622 is advanced to bend the frame 624 to a bent
configuration. And if needed to engage the interior body lumen
1292, the push wire 622 may be advanced even farther to extend the
frame 624 to an extended configuration. Balloon inflation of the
valve can then be performed, and the embolic filter 610 captures
embolic debris 1294 dislodged during the procedure or otherwise in
the blood stream. After balloon pre-dilation, the push wire 622 is
retracted and the outer sheath 612 is advanced to recapture the
embolic filter 610 and any embolic debris 1294 contained within the
embolic filter 610. The balloon is removed, and a second catheter
carrying a valvular prosthesis is advanced to the level of the
ascending aorta by tracking the catheter over the second guidewire.
The outer sheath 612 is again retracted to redeploy the embolic
filter 610 and the push wire 622 is again advanced. The radiopaque
marker(s) 606 allow the user to properly position the valve
prosthesis, for example about 4 mm to about 6 mm below the lower
border of the noncoronary cusp. After the procedure is completed,
the push wire 622 is retracted and the outer sheath 612 is advanced
to recapture the embolic filter 610 and any captured embolic debris
1294, and the catheters are removed from the body. In some
embodiments, the second catheter can be removed prior to
recapturing the embolic filter 610 and embolic debris 1294.
[0178] In other embodiments, the procedure is a cardiac valve
repair procedure. The method described herein can also be adapted
for a mitral valve repair or replacement procedure. In some
embodiments, the procedure is a radio frequency ablation procedure,
for example to treat atrial fibrillation. In some embodiments, the
procedure is a catheterization procedure or structural heart
procedure.
[0179] In other embodiments, a method of capturing embolic debris
as described herein may include inserting a second catheter device
through the same vessel as the embolic protection device. The
second catheter device may be inserted after the embolic protection
device and may be tracked along a longitudinal groove in the outer
surface of the embolic protection device. For example, a valve
delivery catheter device may be guided alongside the embolic
protection device and beyond the distal end of the embolic
protection device by tracking the valve delivery device along the
groove. Advantageously, the second device may be tracked along the
groove and pass beyond the embolic protection device while the
embolic filter is deployed as shown, for example, in FIG. 13A.
[0180] Another aspect of the present invention provides a method of
capturing embolic debris during a closed-heart procedure,
comprising inserting a distal end of a embolic protection device
into a body lumen, the embolic protection device comprising a
catheter having a proximal end, a distal end, and a lumen extending
from the proximal end of the catheter to the distal end of the
catheter, wherein the lumen is configured to house a guidewire, and
a distal portion of the catheter that assumes a generally arcuate
shape being at least a semi-circle when the guidewire is at least
partially longitudinally retracted; a self-expanding embolic filter
that is disposed around the catheter proximal to the distal
portion, wherein the embolic filter comprises a frame, and the
frame defines an opening of the embolic filter; a deployment
mechanism that is disposed around at least a portion of the
catheter, wherein the deployment mechanism is longitudinally
movable with respect to the catheter, the deployment mechanism is
configured to contain the embolic filter in a collapsed
configuration, and the embolic filter is configured to self-expand
upon longitudinal retraction of the deployment mechanism; and a
wire coupled to the frame of the embolic filter, wherein the wire
is longitudinally movable with respect to the catheter; when the
wire is longitudinally advanced, in a distal direction, to a first
position, the wire is configured to bend the frame longitudinally
towards the distal end of the catheter and laterally outward from
the catheter, such that the opening of the embolic filter generally
faces the distal end of the catheter and expands to a first
diameter; and when the wire is longitudinally advanced, in the
distal direction, to a second position distally farther than the
first position, the wire is configured to extend the frame radially
outward from the catheter, such that the opening of the embolic
filter expands to a second diameter larger than the first diameter.
The method further includes tracking the lumen of the catheter over
the guidewire that is percutaneously inserted into the body
lumen.
[0181] Other embodiments further comprise at least partially
longitudinally retracting the guidewire from the lumen of the
catheter, so that the distal portion of the catheter assumes a
generally arcuate shape being at least a semi-circle.
[0182] In other embodiments, the distal portion of the catheter
comprises a radiopaque marker; and the method further comprises
positioning the catheter by visualizing the radiopaque marker using
an imaging technique.
[0183] Other embodiments comprise at least partially longitudinally
retracting the deployment mechanism and allowing the self-expanding
embolic filter to assume an expanded, deployed configuration.
[0184] Other embodiments comprise longitudinally advancing the
wire, thereby bending the frame longitudinally toward the proximal
end of the catheter and laterally outward from the catheter,
wherein the opening defined by the frame substantially spans the
body lumen.
[0185] Other embodiments comprise longitudinally advancing the wire
to the first position, thereby bending the frame longitudinally
towards the distal end of the catheter and laterally outward from
the catheter, and expanding the opening of the embolic filter to
the first diameter, which substantially spans the body lumen.
[0186] Other embodiments comprise longitudinally advancing the wire
to the second position distally farther than the first position,
thereby extending the frame radially outward from the catheter and
expanding the opening of the embolic filter to the second diameter
larger than the first diameter, which substantially spans the body
lumen.
[0187] In other embodiments, the deployment mechanism is a sheath
that is circumferentially disposed around at least a portion of the
catheter.
[0188] In other embodiments, the distal portion of the catheter
comprises one or more apertures that communicate with the lumen of
the catheter; the method further comprising perfusing a fluid into
the body lumen through the one or more apertures.
[0189] In other embodiments, the embolic protection device
comprises a longitudinal groove along an outer surface of the
embolic protection device; the method further comprising inserting
a second catheter device alongside the embolic protection device by
tracking the second catheter device along the groove.
[0190] In other embodiments, the second catheter device is advanced
past the embolic filter of the embolic protection device while the
embolic filter is in a deployed configuration.
[0191] Another aspect of the present invention provides a method of
capturing embolic debris during a closed-heart procedure, the
method comprising inserting a distal end of a embolic protection
device into a body lumen, the embolic protection device comprising
a catheter having a proximal end, a distal end, and a lumen
extending from the proximal end of the catheter to the distal end
of the catheter, wherein the lumen is configured to house a
guidewire, and a distal portion of the catheter assumes a generally
arcuate shape being at least a semi-circle when the guidewire is at
least partially longitudinally retracted; a self-expanding embolic
filter that is disposed around the catheter proximal to the distal
portion, wherein the embolic filter comprises a frame, and the
frame defines an opening of the embolic filter; a deployment
mechanism that is disposed around at least a portion of the
catheter, wherein the deployment mechanism is longitudinally
movable with respect to the catheter, the deployment mechanism is
configured to contain the embolic filter in a collapsed
configuration, and the embolic filter is configured to self-expand
upon longitudinal retraction of the deployment mechanism; a wire
coupled to the frame of the self-expanding filter, wherein the wire
is longitudinally movable.
[0192] The method further includes tracking the lumen of the
catheter over the guidewire that is percutaneously inserted into
the body lumen and at least partially longitudinally retracting the
guidewire from the lumen of the catheter, so that the distal
portion of the catheter assumes a generally arcuate shape being at
least a semi-circle upon retracting the guidewire from the distal
portion of the catheter. The method further includes longitudinally
retracting the deployment mechanism and deploying the
self-expanding embolic filter. The method further includes
longitudinally advancing the wire, in a distal direction, to a
first position, thereby bending the frame longitudinally towards
the distal end of the catheter and laterally outward from the
catheter, and expanding the opening of the embolic filter to a
first diameter.
IV. EXAMPLES
Example 1
Cadaver Model
[0193] Referring to FIGS. 13A and 13B, an embolic protection device
of the present invention (EPD-1) was tested in a human cadaver
model to visually assess the device's ability to cover all cerebral
vessels with an embolic filter while an endovascular device was
passed through the aorta and alongside the EPD-1. In the
photographs of FIGS. 13A and 13B, the EPD-1 is deployed and
covering the opening of cerebral vessels of the cadaver while at
the same time, a TAVR delivery system passes above the filter. In
FIG. 13A, the TAVR delivery system is tracked along a longitudinal
groove on the outer surface of the EPD-1 catheter. In FIG. 13B, the
TAVR delivery system is tracked outside the groove of the EPD-1
catheter.
EXAMPLE 2
Clinical Study
[0194] Referring to FIG. 14 and FIGS. 15A-15J, the safety and
performance of an embolic protection device according to the
present invention ("EPD-1") was assessed during transcatheter
aortic valve replacement (TAVR) procedures on human subjects. The
primary objective was to evaluate the performance and the treatment
of effect of the use of the EPD-1 during TAVR with respect to
procedure-related cerebral embolic burden as determined by
diffusion-weighted magnetic resonance imaging (DW-MRI). A secondary
objective was to analyze the safety profile and type of captured
debris from the EPD-1 filter after TAVR.
[0195] The study was designed as a multi-center non-randomized
trial including up to 5 clinical sites to evaluate the performance
and the treatment effect of the use of the EPD-1 during TAVR with
respect to procedure-related silent ischemic damage and cerebral
embolic burden, as determined by DW-MRI studies performed before
and after the procedure. A secondary objective was to analyze the
safety profile and the type of captured debris from the EPD-1
filter after TAVR. The potential risk of neurological compromise
and stroke was assessed based on neurological evaluations pre and
post procedure. The study population was comprised of up to thirty
(30) subjects with severe native aortic valve stenosis who meet the
commercially approved indications for TAVR and complied with the
inclusion/exclusion criteria.
[0196] Primary Endpoints: 1) Device performance: defined as the
successful insertion, placement, and removal of the EPD-1. Device
performance was evaluated during and after completion of the TAVR
index procedure. 2) Acute cerebral embolic burden reduction after
TAVR, defined as number and volume of brain lesions detected with
DW MRI at Day 2-5 post TAVR procedure compared with baseline.
[0197] Secondary Endpoints: 1) Rate of major adverse cardiac and
cerebrovascular events at 30-days post TAVR index procedure
compared to historical data. Major Adverse Cardiac and
Cerebrovascular Events (MACCE) are defined as: All-cause mortality;
All stroke (major, minor, TIA); Acute Kidney Injury (Class 3). 2)
Clinical assessment of subject's neurological status pre- and
post-index procedure using the NIH stroke scale.
[0198] Eleven subjects were enrolled in a multi-center,
non-randomized, prospective pilot study. The performance
characteristics of the EPD-1 were evaluated post-procedurally and
scored on a 5-point score (1, unacceptable to 5, excellent). The
average performance across all patients of all characteristics for
the EPD-1 was 4.8 at clinical site 1 and 3.4 at clinical site 2.
Average performance scores (at each of the clinical sites) for each
assessed characteristic EPD-1 performance are illustrated in the
bar graphs of FIG. 14. The characteristics scored were: vessel
access, tracking, use of sheath and deployment buttons,
positioning, re-sheathing, removal, visualization during
aortography, deployment, positioning, repositioning, retrieval,
stability, visibility in place, ease to deploy, and ease to
sheath.
[0199] Pre-to-post procedure aortic gradient measurements averaged
86.4% reduction in all eleven (11) subjects confirming success of
TAVR treatments.
[0200] All subjects underwent DW-MRI pre-and-post-procedure, and
evaluation of images were consistent with identification of some
ischemic lesions. MRI was performed at the Baseline and
Pre-Discharge (Day 2-5) visits in the eleven (11) subjects that
underwent a Transcatheter Aortic Valve Replacement (TAVR) procedure
at each of the two clinical sites. The MRI protocol consisted of
the following sequences: Axial DWI, Axial FLAIR and 3D T1-weighted
IR-GRE. DWI contrast is sensitive to water molecules and helps
locate and quantify fresh lesions. Total lesions were counted,
lesion location, size and volume was assessed, and total lesion
volume were analyzed. FIGS. 15A-15J show the DW-MRI images of the
brains for three (3) representative human subjects (001-05, 001-06
and 002-01).
[0201] A median lesion count of 6 and a median lesion volume of
193.9 mm.sup.3 were observed among the eleven (11) subjects. A
breakdown of lesions by location is detailed in Table 1. These
results indicate a lower lesion count and volume when compared to
both historical controls and clinical trials involving cleared and
investigational embolic protection devices.
TABLE-US-00001 TABLE 1 Brain lesions by location for all patients
(clinical sites 1 and 2) from the clinical study. Lesion Vascular
Territory Count Anterior Choroidal Artery 2 Anterior Cerebral
Artery 3 Middle Cerebral Artery 40 Posterior Cerebral Artery 22
Vertebrobasilar Artery 1 Anterior Inferior Cerebellar Artery 0
Posterior Inferior Cerebellar Artery 12 Total Lesion Count (Entire
Brain) 80
[0202] Table 2 provides a detailed comparison of lesion count and
volume between the clinical study of this Example 2 and clinical
studies for comparable devices. These results demonstrate that
protection using the EPD-1 could reduce the number of ischemic
lesions or their volume, thus supporting the utility of the
procedure.
TABLE-US-00002 TABLE 2 Comparison of EPD-1 performance to that of
cleared and investigational devices. Median Time Median Lesion
Range # of Lesion Volume of Study Device Subjects Count (mm.sup.3)
Imaging CLEAN- None (control) 45 16 800 2 D TAVI EXAMPLE 2 EPD-1
11* 6 193.9 <48 hours SENTINEL Claret Medical 91 3 294 2-7 D
Sentinel Protected areas only PROTAVI-C Edwards 42 8 305 7 D
Lifesciences Embrella Embolic Deflector System (investigational)
DEFLECT- TriGuard .TM. HDH 46 N/A 46% > 2-6 D III Embolic 150
Deflection Device (investigational)
[0203] The time point at which MRI was taken differs between these
studies. Whereas DW-MRI was performed within 48 hours
post-procedure for all patients in Example 2; for other referenced
studies, imaging was performed at a longer time point. Because the
appearance of hyper-intensity during DW-MRI imaging is known to
evolve over time, these other referenced studies would have likely
observed a higher lesion volume, had DW-MRI been taken within 48
hours post-procedure. Nonetheless, the EPD-1 outperformed the
referenced, comparable devices with respect to acute cerebral
embolic burden reduction. Three patients had elevated lesion
counts; however, they were considered outliers as the filter was
recaptured and the TAVR device post dilated. During these outlier
procedures, the operators were concerned about interaction of the
balloon catheter with the filter frame due to the small anatomy of
the aorta. This typically results in liberation of debris.
[0204] The EPD-1 captured thrombi in all procedures. Two examples
of captured thrombi are shown in the photographs of FIGS. 16A and
16B. The photograph of FIG. 16A shows a thrombi captured by the
EPD-1 of Example 2. The photograph of FIG. 16B shows an actual
pathologic finding of a 4.6 mm collagenous fragment captured within
the EPD-1 filter during a TAVR procedure. Neurological evaluation
of all patients using NIHSS at discharge and 30 days post-procedure
showed that scores for all patients remained at baseline levels,
except for one patient developing limb ataxia. No serious adverse
events were recorded. Debris captured by the embolic filter of the
EPD-1 included collagen, fibrin, thrombi, and calcium.
[0205] A summary of endpoints is shown in Table 3.
TABLE-US-00003 TABLE 3 Summary of endpoints from the clinical
studies of Example 2. Result Endpoints Success Failure Primary
Endpoints Device performance successful 100% 0% deployment and
retrieval Acute cerebral embolic burden The EPD-1 device showed
reduction reduction after TAVR in acute cerebral embolic burden
when compared to both historical controls and other marketed and
investigational devices. Secondary Endpoints MACCE, 30-days post-
100% 0% procedure (No Events) NIH stroke scale pre-and-post- 100%
0% procedure (Scores = 0) Gross histologic evaluation of 100% 0%
embolic debris captured
Other Embodiments
[0206] It is to be understood that while the invention has been
described in conjunction with the detailed description thereof, the
foregoing description is intended to illustrate and not limit the
scope of the invention, which is defined by the scope of the
appended claims. Other aspects, advantages, and modifications are
within the scope of the following claims.
[0207] It is to be understood by one having ordinary skill in the
art that the specific devices and processes illustrated in the
attached drawings and described in this specification are simply
example embodiments of the inventive concepts defined in the
appended claims. Hence, specific dimensions and other physical
characteristics relating to the embodiments disclosed herein are
not to be considered as limiting, unless the claims expressly state
otherwise. It is also to be understood that construction of the
described invention and other components is not limited to any
specific material. Other example embodiments of the invention
disclosed herein may be formed from a wide variety of materials,
unless described otherwise herein.
[0208] Changes and modifications in the specifically-described
embodiments may be carried out without departing from the
principles of the present invention, which is intended to be
limited only by the scope of the appended claims as interpreted
according to the principles of patent law including the doctrine of
equivalents.
* * * * *