U.S. patent application number 09/855430 was filed with the patent office on 2001-10-18 for embolic protection system and method including an emboli-capturing catheter.
Invention is credited to Peterson, Charles R., Simpson, John A..
Application Number | 20010031982 09/855430 |
Document ID | / |
Family ID | 23757660 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010031982 |
Kind Code |
A1 |
Peterson, Charles R. ; et
al. |
October 18, 2001 |
Embolic protection system and method including an emboli-capturing
catheter
Abstract
A system used in a blood vessel when an interventional procedure
is being performed in a stenosed or occluded region to capture any
embolic material which may be created and released into the
bloodstream during the procedure. The system includes an
emboli-capturing catheter which is capable of occluding a blood
vessel distal to or at an interventional procedure site, perfusing
the blood to enable blood to flow past the occlusion, and filtering
the blood to capture embolic material which may be released into
the blood during a therapeutic interventional procedure. The
emboli-capturing catheter includes an expandable member which is
capable of being expanded distal to or at the area of treatment at
the interventional procedure site for occluding the blood vessel.
The catheter further includes a plurality of perfusion inlet
openings for enabling blood and emboli to pass therethrough, and an
outlet opening or openings which, in cooperation with the filter
media, are adapted to enable blood to pass therethrough while
preventing emboli from passing therethrough. The catheter also
includes filter media located in the distal end of the catheter or
capable of being deployed outside and distal of the catheter for
filtering the blood to capture any released embolic material.
Inventors: |
Peterson, Charles R.;
(Murrieta, CA) ; Simpson, John A.; (Carlsbad,
CA) |
Correspondence
Address: |
FULWIDER PATTON LEE & UTECHT, LLP
HOWARD HUGHES CENTER
6060 CENTER DRIVE
TENTH FLOOR
LOS ANGELES
CA
90045
US
|
Family ID: |
23757660 |
Appl. No.: |
09/855430 |
Filed: |
May 14, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09855430 |
May 14, 2001 |
|
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|
09442667 |
Nov 18, 1999 |
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Current U.S.
Class: |
606/200 ;
604/102.01 |
Current CPC
Class: |
A61F 2002/018 20130101;
A61F 2/01 20130101; A61M 2025/1095 20130101; A61F 2230/0069
20130101; A61M 2025/109 20130101; A61F 2230/0006 20130101 |
Class at
Publication: |
606/200 ;
604/102.01 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. A system for capturing embolic material which may be released
into a blood vessel during a therapeutic interventional procedure,
comprising: a catheter, adapted to occlude a blood vessel at a
location distal to or at an interventional procedure site, to
perfuse the blood to enable blood to flow past the occlusion, and
to capture embolic material which may be released into the blood in
the blood vessel during a therapeutic interventional procedure,
including: an elongated shaft, which includes proximal and distal
ends, and which has a lumen therein, and a plurality of perfusion
openings in the distal end portion thereof for perfusing the blood
past the occlusion: an expandable member, adapted to be located in
the distal end portion of the catheter shaft and to be expandable
within the blood vessel at a location distal to or at the
interventional procedure site so as to occlude the blood vessel;
and filter media, adapted to be located in the distal end portion
of the catheter shaft distal of the expandable member and to be
positionable within the blood vessel distal to the interventional
procedure site, for passing blood therethrough and capturing
embolic material which may be released into the blood in the blood
vessel during the interventional procedure.
2. The system of claim 1, wherein the catheter includes an
inflation lumen in fluid communication with the expandable member
adapted to inflate the expandable member outwardly upon receipt of
fluid through the inflation lumen and to collapse the expandable
member inwardly towards the elongated shaft upon evacuation from
the inflation lumen.
3. The system of claim 1, wherein the plurality of perfusion
openings include a plurality of inlet openings located proximal of
the expandable member, which communicate with the lumen, for
perfusion of the blood, to enable blood which is flowing through
the blood vessel and blocked by the expandable member, and embolic
material which may be released into the blood during the
interventional procedure, to flow therethrough, and an outlet
opening located distal to the expandable member, which communicates
with the main lumen, for perfusion of the blood, to enable blood
which flows through the filter media to flow into and through the
blood vessel.
4. The system of claim 1, wherein the lumen comprises a perfusion
lumen which permits blood flow past the filter media.
5. The system of claim 1, further comprising a guide wire for
guiding movement of the emboli-capturing catheter.
6. The system of claim 1, further comprising an interventional
instrument catheter adapted to be movable along the
emboli-capturing catheter so as to pass interventional instruments
to the interventional procedure site.
7. The system of claim 3, wherein the outlet opening comprises a
plurality of outlet openings positioned at circumferentially
spaced-apart locations about the catheter shaft proximate to the
distal end of the catheter shaft.
8. The system of claim 3, wherein the plurality of inlet openings
are adapted to enable emboli to pass therethrough.
9. The system of claim 3, wherein the outlet opening is adapted to
prevent emboli from passing therethrough.
10. A system for capturing embolic material which may be released
into a blood vessel during a therapeutic interventional procedure,
comprising: a catheter, adapted to occlude a blood vessel at a
location distal to an interventional procedure site, to perfuse the
blood to enable blood to flow past the occlusion, and to capture
embolic material which may be released into the blood in the blood
vessel during a therapeutic interventional procedure, including: an
elongated shaft, which includes proximal and distal ends, and which
has a lumen therein, and a plurality of perfusion openings in the
distal end portion thereof for perfusing the blood past the
occlusion: an expandable member, adapted to be located in the
distal end portion of the catheter shaft and to be expandable
within the blood vessel at a location distal to the interventional
procedure site so as to occlude the blood vessel; and filter media,
adapted to be located in the distal end portion of the catheter
shaft distal of the expandable member and to be positionable within
the blood vessel distal to the interventional procedure site, for
passing blood therethrough and capturing embolic material which may
be released into the blood in the blood vessel during the
interventional procedure.
11. The system of claim 10, wherein the plurality of perfusion
openings include a plurality of inlet openings located proximal of
the expandable member, which communicate with the lumen, for
perfusion of the blood, to enable blood which is flowing through
the blood vessel and blocked by the expandable member, and embolic
material which may be released into the blood during the
interventional procedure, to flow therethrough, and an outlet
opening located distal to the expandable member, which communicates
with the main lumen, for perfusion of the blood, to enable blood
which flows through the filter media to flow into and through the
blood vessel.
12. The system of claim 10, wherein the filter media include coarse
mesh filter media and fine mesh filter media.
13. The system of claim 10, wherein the filter media comprise a
plurality of stages of filter material.
14. The system of claim 11, wherein the outlet opening comprises a
plurality of outlet openings positioned at circumferentially
spaced-apart locations about the catheter shaft proximate to the
distal end of the catheter shaft.
15. The system of claim 12, wherein the fine mesh filter media are
adapted to be positioned proximate to the outlet opening.
16. The system of claim 13, wherein the plurality of stages of the
filter material comprise a first stage of coarse mesh filer
material, and a second stage of fine mesh filter material, adapted
to be positioned in the catheter such that the second stage is
distal to the first stage.
17. The system of claim 14, wherein the filter media include fine
mesh filter media, and the fine mesh filter media are adapted to be
shaped so as to extend about the inner wall of the distal end
portion of the lumen so as to cover the plurality of outlet
openings.
18. The system of claim 15, wherein the coarse mesh filter media
are adapted to be positioned proximal of the fine mesh filter
media.
19. The system of claim 17, wherein the shape of the filter media
comprises a generally tubular shape.
20. A system for capturing embolic material which may be released
into a blood vessel during a therapeutic interventional procedure,
comprising: a catheter, adapted to occlude a blood vessel at a
location at an interventional procedure site, to perfuse the blood
to enable blood to flow past the occlusion, and to capture embolic
material which may be released into the blood in the blood vessel
during a therapeutic interventional procedure, including: an
elongated shaft, which includes proximal and distal ends, and which
has a lumen therein, and a plurality of perfusion openings in the
distal end portion thereof for perfusing the blood occlusion; an
expandable member, adapted to be located in the distal end portion
of the catheter shaft and to be expandable within the blood vessel
at a location at the interventional procedure site so as to occlude
the blood vessel; and filter media, adapted to be located in the
distal end portion of the catheter shaft distal of the expandable
member and to be positionable within the blood vessel distal to the
interventional procedure site, for passing blood therethrough and
capturing embolic material which may be released into the blood in
the blood vessel during the interventional procedure, wherein the
filter media are further adapted to be deployed outside the distal
end of the catheter elongated shaft.
21. The system of claim 20, wherein the filter media are adapted to
be expandable upon projection thereof through the distal end of the
embolic-capturing catheter elongated shaft into the blood vessel,
distal to the interventional procedure site, so as to capture
emboli therein.
22. The system of claim 21, wherein the filter media are further
adapted to be collapsible upon retraction thereof into the catheter
shaft lumen.
23. A method of capturing embolic material released into a blood
vessel during a therapeutic interventional procedure, in a system
which comprises a catheter, adapted to occlude a blood vessel at a
location distal to or at an interventional procedure side, to
perfuse the blood to enable blood to flow past the occlusion, and
to capture embolic material which may be released into the blood in
the blood vessel during a therapeutic interventional procedure,
including an elongated shaft, which includes proximal and distal
ends, and which has a lumen therein, and a plurality of perfusion
openings in the distal end portion thereof for perfusing the blood
past the occlusion, an expandable member, adapted to be located in
the distal end portion of the catheter shaft and to be expandable
within the blood vessel at a location distal to or at the
interventional procedure site so as to occlude the blood vessel,
and filter media, adapted to be located in the distal end portion
of the catheter shaft distal of the expandable member and to be
positionable within the blood vessel distal to the interventional
procedure site, for passing blood therethrough and capturing
embolic material which may be released into the blood in the blood
vessel during the interventional procedure, wherein the method
comprises: positioning the catheter in the interventional procedure
site such that the expandable member and the filter media are
located within the blood vessel in the region at a location distal
to or at the interventional procedure site; expanding the
expandable member within the blood vessel at the location distal to
or at the interventional procedure site so as to occlude the blood
vessel; perfusing the blood through the catheter; performing the
interventional procedure, which may release embolic material into
the blood; and filtering the blood through the filter media so as
to capture embolic material which may be released into the blood
upon performing the interventional procedure.
24. The method of claim 23, wherein the catheter includes an
inflation lumen in fluid communication with the expandable member,
adapted to inflate the expandable member outwardly upon receipt of
fluid through the inflation lumen and to collapse the expandable
member inwardly towards the elongated shaft-upon evacuation of
fluid from the inflation lumen, and wherein expanding the expanding
member further comprises pumping the fluid through the inflation
lumen to inflate the expandable member.
25. The method of claim 23, wherein the plurality of perfusion
openings include a plurality of inlet openings located proximal of
the expandable member, which communicate with the lumen, for
perfusion of the blood, to enable blood which is flowing through
the blood vessel and blocked by the expandable member, and embolic
material which may be released into the blood during the
interventional procedure, to flow therethrough, and an outlet
opening located distal to the expandable member, which communicates
with the main lumen, for perfusion of the blood, to enable blood
which flows through the filter media to flow into and through the
blood vessel, wherein perfusing further comprises perfusing the
blood and the embolic material which may be released into the blood
through the plurality of inlet openings and the filter media, and
perfusing the blood through the outlet opening into the blood
vessel.
26. The method of claim 23, wherein the lumen comprises a perfusion
lumen which permits blood flow past the positioned filtering
member, further comprising perfusing the blood and the embolic
material which may be released into the blood through the perfusion
lumen and past the filter media.
27. The method of claim 23, further comprising a guide wire for
guiding movement of the emboli-capturing catheter, further
comprising guiding movement of the emboli-capturing catheter along
the guide wire.
28. The method of claim 23, further comprising an interventional
instrument catheter for passing interventional instruments along
the emboli-capturing catheter to the interventional procedure site,
further comprising passing the interventional instrument catheter
along the emboli-capturing catheter to the interventional procedure
site.
29. A method of capturing embolic material released into a blood
vessel during a therapeutic interventional procedure, in a system
which comprises a catheter, adapted to occlude a blood vessel at a
location distal to an interventional procedure side, to perfuse the
blood to enable blood to flow past the occlusion, and to capture
embolic material which may be released into the blood in the blood
vessel during a therapeutic interventional procedure, including an
elongated shaft, which includes proximal and distal ends, and which
has a lumen therein, and a plurality of perfusion openings in the
distal end portion thereof for perfusing the blood past the
occlusion, an expandable member, adapted to be located in the
distal end portion of the catheter shaft and to be expandable
within the blood vessel at a location distal to the interventional
procedure site so as to occlude the blood vessel, and filter media,
adapted to be located in the distal end portion of the catheter
shaft distal of the expandable member and to be positionable within
the blood vessel distal to the interventional procedure site, for
passing blood therethrough and capturing embolic material which may
be released into the blood in the blood vessel during the
interventional procedure, wherein the method comprises: positioning
the catheter in the interventional procedure site such that the
expandable member and the filter media are located within the blood
vessel in the region at a location distal to the interventional
procedure site; expanding the expandable member within the blood
vessel at the location distal to the interventional procedure site
so as to occlude the blood vessel; perfusing the blood through the
catheter; performing the interventional procedure, which may
release embolic material into the blood; and filtering the blood
through the filter media so as to capture embolic material which
may be released into the blood upon performing the interventional
procedure.
30. The method of claim 29, wherein the plurality of perfusion
openings include a plurality of inlet openings located proximal of
the expandable member, which communicate with the lumen, for
perfusion of the blood, to enable blood which is flowing through
the blood vessel and blocked by the expandable member, and embolic
material which may be released into the blood during the
interventional procedure, to flow therethrough, and an outlet
opening located distal to the expandable member, which communicates
with the main lumen, for perfusion of the blood, to enable blood
which flows through the filter media to flow into and through the
blood vessel, wherein perfusing further comprises perfusing the
blood and the embolic material which may be released into the blood
through the plurality of inlet openings and the filter media, and
perfusing the blood through the outlet opening into the blood
vessel.
31. The method of claim 29, wherein the filter media include coarse
mesh filter media and fine mesh filter media, and wherein filtering
further comprises filtering the blood through the coarse mesh
filter media and the fine mesh filter media.
32. The system of claim 29, wherein the filter media comprise a
plurality of stages of filter material, and wherein filtering
further comprises filtering the blood through the plurality of
stages of the filter material.
33. A method of capturing embolic material released into a blood
vessel during a therapeutic interventional procedure, in a system
which comprises a catheter, adapted to occlude a blood vessel at a
location at an interventional procedure side, to perfuse the blood
to enable blood to flow past the occlusion, and to capture embolic
material which may be released into the blood in the blood vessel
during a therapeutic interventional procedure, including an
elongated shaft, which includes proximal and distal ends, and which
has a lumen therein, and a plurality of perfusion openings in the
distal end portion thereof for perusing the blood past the
occlusion, an expandable member, adapted to be located in the
distal end portion of the catheter shaft and to be expandable
within the blood vessel at a location at the interventional
procedure site so as to occlude the blood vessel, and filter media,
adapted to be located in the distal end portion of the catheter
shaft distal of the expandable member and to be positionable within
the blood vessel distal to the interventional procedure site, for
passing blood therethrough and capturing embolic material which may
be released into the blood in the blood vessel during the
interventional procedure, wherein the filter media are further
adapted to be deployed outside the distal end of the catheter
elongated shaft, and wherein the method comprises: positioning the
catheter in the interventional procedure site such that the
expandable member and the filter media are located within the blood
vessel in the region at a location at the interventional procedure
site; expanding the expandable member within the blood vessel at
the location at the interventional procedure site so as to occlude
the blood vessel; perfusing the blood through the catheter;
deploying the filter media outside the distal end of the catheter
elongated shaft; retracting the expanding member; performing the
interventional procedure, which may release embolic material into
the blood; and filtering the blood through the deployed filter
media so as to capture embolic material which may be released into
the blood upon performing the interventional procedure.
34. The method of claim 33, wherein the filter media are adapted to
be expandable upon projection thereof through the distal end of the
emboli-capturing catheter elongated shaft into the blood vessel,
distal to the interventional procedure site, so as to capture
emboli therein, and wherein filtering further comprises projecting
the filter media through the distal end of the emboli-capturing
catheter elongated shaft into the blood vessel distal to the
interventional procedure site whereupon the filter media expand so
as to capture emboli therein.
35. The method of claim 34, wherein the filter media are farther
adapted to be collapsible upon retraction thereof into the catheter
shaft lumen, and wherein filtering further comprises retracting the
filter media into the catheter shaft lumen whereupon the filter
media collapse so as to compress the captured emboli therein.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to a system which
can be used when an interventional procedure is being performed in
a stenosed or occluded region of a blood vessel to capture any
embolic material that may be created and released into the
bloodstream during the procedure. The system of the present
invention is particularly useful when performing balloon
angioplasty, stenting procedures, laser angioplasty or atherectomy
in critical vessels, such as the carotid arteries, where the
release of embolic debris into the bloodstream can occlude the flow
of oxygenated blood to the brain or other vital organs which can
cause devastating consequences to the patient.
[0002] A variety of non-surgical interventional procedures have
been developed over the years for opening stenosed or occluded
blood vessels in a patient caused by the build up of plaque or
other substances on the walls of the blood vessel. Such procedures
usually involve the percutaneous introduction of the interventional
device into the lumen of the artery, usually through a catheter.
One widely known and medically accepted procedure is balloon
angioplasty in which an inflatable balloon is introduced within the
stenosed region of the blood vessel to dilate the occluded vessel.
The balloon catheter is initially inserted into the patient's
arterial system and is advanced and manipulated into the area of
stenosis in the artery. The balloon is inflated to compress the
plaque and press the vessel wall radially outward to increase the
diameter of the blood vessel.
[0003] Another procedure is laser angioplasty which utilizes a
laser to ablate the stenosis by super heating and vaporizing the
deposited plaque. Atherectomy is yet another method of treating a
stenosed blood vessel in which a cutting blade is rotated to shave
the deposited plaque from the arterial wall. A vacuum catheter is
usually used to capture the shaved plaque or thrombus from the
blood stream during this procedure.
[0004] In another widely practiced procedure, the stenosis can be
treated by placing a device known as a stent into the stenosed
region to hold open and sometimes expand the segment of blood
vessel or other arterial lumen. Stents are particularly useful in
the treatment or repair of blood vessels after a stenosis has been
compressed by percutaneous transluminal coronary angioplasty
(PTCA), percutaneous transluminal angioplasty (PTA) or removal by
atherectomy or other means. Stents are usually delivered in a
compressed condition to the target site, and then are deployed at
the target location into an expanded condition to support the
vessel and help maintain it in an open position.
[0005] Prior art stents typically fall into two general categories
of construction. The first type of stent is expandable upon
application of a controlled force, often through the inflation of
the balloon portion of a dilatation catheter which, upon inflation
of the balloon or other expansion means, expands the compressed
stent to a larger diameter to be left in place within the artery at
the target site. The second type of stent is a self-expanding stent
formed from, for example, shape memory metals or super-elastic
nickel-titanum (NiTi) alloys, which will automatically expand from
a compressed state when the stent is advanced out of the distal end
of the delivery catheter into the body lumen. Such stents
manufactured from expandable heat sensitive materials allow for
phase transformations of the material to occur, resulting in the
expansion and contraction of the stent.
[0006] The above non-surgical interventional procedures, when
successful, avoid the necessity of major surgical operations.
However, there is one common problem associated with all of these
non-surgical procedures, namely, the potential release of embolic
debris into the bloodstream which can occlude distal vasculature
and cause significant health problems to the patient. For example,
during deployment of a stent, it is possible that the metal struts
of the stent can cut into the stenosis and shear off pieces of
plaque which become embolic debris that can travel downstream and
lodge somewhere in the patient's vascular system. Pieces of plaque
material can sometimes dislodge from the stenosis during a balloon
angioplasty procedure and become released into the bloodstream.
Additionally, while complete vaporization of plaque is the intended
goal during a laser angioplasty procedure, quite often particles
are not fully vaporized and enter the bloodstream. Likewise, not
all of the emboli created during an atherectomy procedure may be
drawn into the vacuum catheter and, as a result, the remaining
emboli may enter the bloodstream as well.
[0007] When any of the above-described procedures are performed in
the cerebral arteries, the release of emboli into the circulatory
system can be extremely dangerous and sometimes fatal to the
patient. Debris that is carried by the bloodstream to distal
vessels of the brain can cause these cerebral vessels to occlude,
resulting in a stroke, and in some cases, death. Therefore,
although cerebral percutaneous transluminal angioplasty has been
performed in the past, the number of procedures performed has been
limited due to the justifiable fear of causing an embolic stroke
should embolic debris enter the bloodstream and block vital
downstream blood passages.
[0008] Medical devices have been developed to attempt to deal with
the problem created when debris or fragments enter the circulatory
system following treatment utilizing any one of the
above-identified procedures. One approach which has been attempted
is the cutting of any debris into minute sizes which pose little
chance of becoming occluded in major vessels within the patient's
vasculature. However, it is often difficult to control the size of
the fragments which are formed, and the potential risk of vessel
occlusion still exists, making such procedures in the carotid
arteries a high-risk proposition.
[0009] Other techniques which have been developed to address the
problem of removing embolic debris include the use of catheters
with a vacuum source which provides temporary suction to remove
embolic debris from the bloodstream. However, as mentioned above,
there have been complications with such systems since the vacuum
catheter may not always remove all of the embolic material from the
bloodstream, and a powerful suction could cause problems to the
patient's vasculature. Further techniques which have had some
limited success include the placement of a filter or trap
downstream from the treatment site to capture embolic debris before
it reaches the smaller blood vessels downstream. However, there
have been problems associated with filtering systems, particularly
during the expansion and collapsing of the filter within the body
vessel. If the filtering device does not have a suitable mechanism
for closing the filter, there is a possibility that trapped embolic
debris can backflow through the open end of the filter and enter
the bloodstream as the filtering system is being collapsed for
removal from the patient. In such a case, the act of collapsing the
filter device may actually squeeze trapped embolic material through
the opening of the filter. In other instances, the rate of blood
percolating through the filtering material may be slower than the
normal blood flow which can either cause the filtering material to
tear or cause the filter to become displaced with the vessel due to
the build up of fluid pressure behind the filter. Moreover, should
the filter become clogged with debris, there is a possibility that
blood circulation past the clogged filter will be insufficient for
the downstream vessels and organs. If a filter should become
clogged when in use in the carotid arteries, blood flow could be
diminished to the vessels leading to the brain. While the brain may
be capable of functioning for a short period of time without
sufficient blood flow, blood stoppage of more than thirty to forty
seconds could cause the patient to experience a seizure. If the
physician administering the procedure is unaware that the filtering
device is clogged and that there is little or no blood flowing to
the brain, the injury to the patient can be as devastating as if an
emboli itself had caused blockage of the cerebral arteries.
[0010] What has been needed is a reliable system and method for
treating stenosis in blood vessels which prevent the risk of
releasing embolic debris into the bloodstream that can cause
blockage in vessels at downstream locations. The system and method
should be capable of filtering any embolic debris which may be
released into the bloodstream during the treatment, and yet allow a
sufficient amount of oxygenated blood to flow past the filtering
device to supply vital organs downstream from the treatment site.
The system and method should be relatively easy for a physician to
use and should provide a failsafe filtering system which removes
all embolic debris from the bloodstream. Moreover, such a system
should be relatively easy to deploy and remove from the patient's
vasculature. The inventions disclosed herein satisfy all of these
needs.
SUMMARY OF INVENTION
[0011] The present invention provides a system and method for
capturing embolic debris in a blood vessel which may be created
during the performance of a therapeutic interventional procedure,
such as a balloon angioplasty or stenting procedure, in order to
prevent the embolic debris from lodging and blocking blood vessels
downstream from the interventional site. The present invention is
particularly useful while performing an interventional procedure in
vital arteries, such as the carotid arteries, in which critical
downstream blood vessels can become blocked with embolic debris,
including the main blood vessels leading to the brain or other
vital organs. As a result, the present invention provides the
physician with a higher degree of confidence that any and all
embolic debris is being collected and removed from the blood vessel
when performing high-risk interventional procedures.
[0012] The present invention occludes the blood vessel at a
location distal to or at the area of treatment in the
interventional procedure site, perfuses the blood to enable blood
to flow past the occlusion, and filters the blood to capture any
embolic debris which may be created during the interventional
procedure.
[0013] In the present invention, the system includes an
emboli-capturing catheter with an occlusion balloon to occlude a
blood vessel, a plurality of perfusion openings to perfuse the
blood past the occlusion, and filter media to capture embolic
material. The emboli-capturing catheter of the present invention
directs the blood flow through the area where the interventional
procedure is to be performed and through the filter media located
relative to the interventional site, which are designed to capture
any friable plaque deposits. Additionally, the present invention
allows blood to perfuse past the filter media to provide a
continuous stream of blood to the organs located downstream.
[0014] In one particular embodiment of the present invention, the
embolic protection system includes an emboli-capturing catheter
which includes an elongated catheter body which has a proximal and
distal end along with a main lumen which extends through the
catheter body. An expandable member, such as an inflatable balloon,
located near the distal end of the elongated catheter body, is in
fluid communication with an inflation lumen. Upon inflation with a
suitable fluid, the expandable member can be deployed within the
blood vessel to prevent blood flow past the expandable member, for
occluding the blood vessel at a location distal to the
interventional procedure site. A plurality of perfusion openings in
the elongated catheter body include inlet openings located proximal
to the expandable member which extend into the main lumen, and an
outlet opening or a plurality of outlet openings located at the
distal end portion of the catheter body. As a result, even though
the expandable member occludes the blood vessel, the blood will
continue to flow into the catheter body through the perfusion inlet
openings and through the perfusion lumen past the expandable member
and out the perfusion outlet opening or openings. The blood flowing
through the perfusion inlet openings and the catheter body lumen
directs any embolic debris into the filter media positioned
internally in the distal end portion of the catheter body and
distal of the interventional site, for capturing embolic material
which may be released into the blood in the blood vessel during the
interventional procedure.
[0015] In another particular embodiment of the present invention,
the embolic protection system includes an emboli-capturing catheter
including an elongated catheter body having proximal and distal
ends and a main lumen extending therethrough. The catheter further
includes an expandable member, adapted to be inflated and deployed
at the area of treatment to occlude the blood vessel and to prevent
emboli from forming and being released from the area of treatment
prior to deployment of filter media. The catheter also includes a
plurality of perfusion openings for enabling the blood to continue
to flow through the catheter body and out a distal end opening
therein for perfusion of the blood. The catheter still further
includes filter media adapted to be deployed externally of the
catheter body for capturing embolic material which may be released
into the bloodstream upon deflation of the expandable member and
during the interventional procedure.
[0016] The elongated shaft of the emboli-capturing catheter, once
deployed within the patient's vasculature, can be used as a
guidewire to allow interventional instruments to be moved along the
elongated shaft into the area of treatment in an over-the-wire
arrangement. This eliminates the need to maintain a separate
guidewire in the patient once the emboli-capturing catheter is in
place.
[0017] Other features and advantages of the present invention will
become more apparent from the following detailed description of the
preferred embodiments of the invention, when taken in conjunction
with the accompanying exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is an elevational view, partially in section,
depicting the embolic protection system of the present invention
disposed within the internal carotid artery of the patient, in a
first embodiment of the emboli-capturing catheter including a first
mode of the filter media positioned therein for capturing embolic
material.
[0019] FIG. 2 is an elevational view, partially in section, similar
to that shown in FIG. 1, in the first embodiment of the
emboli-capturing catheter including a second mode of the filter
media positioned therein.
[0020] FIG. 3 is an elevational view, partially in section similar
to that shown in FIG. 1, in the first embodiment of the
emboli-capturing catheter including a third mode of the filter
media positioned therein.
[0021] FIG. 4 is an elevational view, partially in section, of the
embolic protection system of the present invention in a second
embodiment of the emboli-capturing catheter including filter media
deployed therefrom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] The present invention is directed to an improved system and
method for efficiently and effectively capturing embolic debris
which may be released into the bloodstream when performing an
interventional procedure in a blood vessel. The preferred
embodiments of the improved system and method are illustrated and
described herein by way of example only and not by way of
limitation. While the present invention is described in detail as
applied to the carotid arteries of the patient, and the disclosed
interventional procedure is directed to a stenting procedure, those
skilled in the art will appreciate that it can also be used in
other body lumens as well, such as the coronary arteries, renal
arteries, saphenous veins and other peripheral arteries.
Additionally, the present invention can be utilized when performing
any one of a number of interventional procedures, such as balloon
angioplasty, laser angioplasty or atherectomy.
[0023] Referring now to the drawings, wherein like reference
numerals denote like or corresponding parts throughout the drawing
figures, and particularly to FIGS. 1-4, an embolic protection
system 10 is provided for capturing embolic material 12 which may
be released into the blood in a blood vessel 14 during a
therapeutic interventional procedure. The embolic protection system
10 comprises an emboli-capturing catheter 16. The emboli-capturing
catheter 16 is adapted to occlude the blood vessel 14 at a location
distal to or at an interventional procedure site in an area of
treatment 18, to perfuse the blood to enable blood to flow past the
occlusion, and to capture embolic material 12 which may be released
into the blood in the blood vessel 14 during the interventional
procedure. Additional details regarding the particular structure
and shape of the various elements making up the emboli-capturing
catheter 16 are provided below.
[0024] The embolic protection system 10 as shown in FIG. 1 may be
placed within the carotid artery 20 or other blood vessel of the
patient, and may be guided into position by a guide wire 22. The
carotid artery 20 may have an area of treatment 18 wherein
atherosclerotic plaque 24 has built up against the inside wall 26
which decreases the diameter of the carotid artery 20. As a result,
blood flow may be diminished through this area. As will be
discussed below, the therapeutic interventional procedure may
comprise implanting a self-expanding stent 30 in the area of
treatment 18, to compress the build-up of plaque 24 of the stenosis
against the inside wall 26, to increase the diameter of the
occluded area 18 of the artery 20, and to help restore sufficient
flow of blood to the downstream vessels leading to the brain. The
self-expanding stent 30 not only helps increase the diameter of the
occluded area, but may help prevent restenosis in the area of
treatment 18.
[0025] The emboli-capturing catheter 16 includes an elongated shaft
32 having a proximal end 34 and a distal end 36, and which has a
central lumen 38 therein which may function as a perfusion lumen as
described below. The emboli-capturing catheter 16 further includes
an expandable member 40, which is shown in FIGS. 1-4 as an
inflatable balloon, and which is located near a distal end 36 of
the elongated shaft 32 of the emboli-capturing catheter 16. An
inflation lumen (not shown) may also extend from the proximal end
34 to the distal end 36 of the elongated catheter shaft 32. The
inflation lumen may receive and remove fluid, such as saline or
other inflation fluid, for expanding and contracting the expandable
member 40. As can be seen in FIGS. 1-3, the expandable member 40
may be deployed or expanded so as to make full contact with the
walls 26 of the carotid artery 20 to occlude the blood vessel 14
and prevent the blood from flowing past the expandable member 40.
As shown in FIG. 4, the expandable member 40 may be deployed or
expanded at the treatment area 18 so as to make full contact with
the plaque 24 in the walls 26 of the carotid artery 20 so as to
occlude the blood vessel 14 to prevent blood from flowing past the
expandable member 40, and to prevent emboli from forming and being
released from the treatment area 18 prior to deployment of the
filter media 50.
[0026] The elongated shaft 32 of the emboli-capturing catheter 16
further has a plurality of perfusion openings or ports 42 in the
distal end 36 of the emboli-capturing catheter 16, to enable blood
which is flowing through the blood vessel 14 and blocked by the
expandable member 40, and embolic material 12 which may be released
into the blood during the interventional procedure, to flow
therethrough. The perfusion openings 42 include a plurality of
inlet openings 44 located proximal of the expandable member 40,
which communicate with the lumen 38 to allow blood and embolic
material 12 to flow therethrough, and an outlet distal opening 46
adapted to enable blood to flow therethrough and, in cooperation
with the filter media 50, to prevent embolic material 12 from
passing therethrough. Alternatively, a plurality of outlet distal
openings 48 may be positioned at circumferentially spaced-apart
locations about the elongated shaft 32 proximate to the distal end
36.
[0027] The emboli-capturing catheter 16 also includes the filter
media 50 located near the distal end 36 of the elongated shaft 32.
The filter media 50 are adapted to be positioned at a location
within the blood vessel 14 in a region distal to the treatment area
18, for passing blood therethrough and capturing embolic material
12 which may be released into the blood during the interventional
procedure. As shown in the FIG. 1 embodiment of the invention, the
filter media 50 may comprise mesh filter media 52, which include
mesh filtering particles 53 therein, and which are adapted to be
positioned within the distal end 36 of the elongated shaft 32 of
the emboli-capturing catheter 16. As seen in FIG. 2, alternatively,
filter media 54 may include a plurality of stages of filter
material, including a first stage of coarse mesh filter media 56
including coarse mesh filtering particles 57 therein and a second
stage of fine mesh filter media 58 including fine mesh filtering
particles 59 therein, adapted to be positioned in the catheter 16
such that the second stage of fine mesh filter media 58 is distal
to the first stage of coarse mesh filter media 56. As illustrated
in FIG. 3, in another mode, filter media 60 includes fine mesh
filter media 62, including fine mesh filtering particles 63
therein, adapted to be generally tubular in shape so as to extend
about the inner wall of the distal end portion 36 of the central
lumen 38, so as to cover the plurality of distal openings 48, and
coarse mesh filter media 64, including coarse mesh filtering
particles therein 65, about which the fine mesh filter media 62 is
adapted to extend.
[0028] As shown in the embodiment in FIG. 4, alternatively, the
filter media 50 may comprise filter media 66, represented in
phantom in FIG. 4, which filter media 66 may comprise, for example,
a net, a sponge, or the like, adapted to pass through the lumen 38
in collapsed form. The filter media 66 are comprised of material
adapted to capture embolic material 12 while enabling blood to flow
therethrough, such as a mesh fiber. The filter media 66 are adapted
to be deployed externally of the elongated body 32 and outside the
distal end 36 of the elongated shaft 32 of the emboli-capturing
catheter 16. The filter media 66 may be mounted on a dowel 68 or
similar element adapted to be extended through the distal opening
46 of the elongated shaft 32. The filter media 66 are adapted to be
expandable upon projection thereof through the distal end 36 of the
elongated shaft 32 of the emboli-capturing catheter 16, into the
blood vessel 14 distal to the treatment area 18, so as to capture
embolic material 12 therein. The filter media 66 are further
adapted to be collapsible upon retraction thereof into the central
lumen 36 in the elongated shaft 32 of the emboli-capturing catheter
16, along with the embolic material 12 captured therein.
[0029] As shown in FIG. 1, the emboli-capturing catheter 16 may
further include a multi-arm adapter 70 attached to the proximal end
34 of the elongated shaft 32. The embolic protection system 10 may
further comprise an interventional instrument catheter 72, adapted
to be movable along the emboli-capturing catheter 16 so as to pass
interventional instruments such as the self-expanding stent 30 to
the interventional procedure site at the area of treatment 18. The
interventional instrument catheter 72 includes an elongated shaft
74 which includes a proximal end 76 and a distal end 78 for
delivering the interventional instruments (herein the stent 30
located near the distal end 78 of the elongated shaft 76) into the
area of treatment 18. The interventional instrument catheter 72 may
also include a retractable sheath 80 for covering the
self-expanding stent 30 until it is positioned at the treatment
area 18, and for being retracted so as to release the
self-expanding stent 30 at the treatment area 18. The
interventional instrument catheter 72 may further include a
multi-arm adapter 82, such as a Tuohy-Borst adaptor, attached to a
proximal end 76 of the elongated shaft 32.
[0030] In use, as illustrated in FIGS. 1-4, the embolic protection
system 10 may be positioned in the patient's vasculature utilizing
any one of a number of different methods. In one preferred method
of positioning, the embolic-protection catheter 16 may be placed in
the blood vessel 14 by utilizing the guidewire 22 which is inserted
into the patient's vasculature and manipulated by the physician to
the area of treatment 18. Thereafter, once the guidewire 22 is in
place, the embolic-protection catheter 16 may be maneuvered over
the guidewire 22 (via the central lumen 40) using well-known
over-the-wire techniques to place the catheter 16 at a location
proximal to the area of treatment 18. Once the catheter 16 is in
place, the guidewire 22 may be removed from the central lumen 38 by
the physician.
[0031] In the embodiment of FIGS. 1-3, as shown in FIG. 1, once the
catheter 16 is in position in the blood vessel 14 with the
expandable member 40 distal to the treatment area 18, the
expandable member 40 of the catheter 16 may be inflated to occlude
the blood vessel 14 and block the flow of blood entering into the
treatment area 18. In the embodiment of FIG. 4 once the catheter 16
is in position in the blood vessel 14 with the expandable member 40
at the treatment area 18, the expandable member 40 of the catheter
16 may be inflated to occlude the blood vessel 14 and block the
flow of blood entering into the treatment area 18. In both
embodiments, the inflation of the expandable member 40 may be
achieved at the proximal end 34 of the elongated shaft 32 utilizing
the multi-arm adapter 70 which may be attached to an inflation pump
or syringe to expand the expandable member 40.
[0032] Upon inflation of the expandable member 40, whereby the
blood vessel 14 is occluded, the blood is forced to flow through
the inlet openings 44 of the perfusion openings 42 into the central
lumen 38. Blood flowing through the central lumen 38 flows through
the filter media 50, and out of either the outlet distal opening 46
or the outlet distal openings 48 of the catheter 16, for perfusing
the blood to enable blood to flow past the occlusion.
[0033] In the embodiment of the invention illustrated in FIGS. 1-3,
as seen in FIG. 1, once the system 10 is placed in the patient's
vasculature, with the expandable member 40 positioned distal to the
treatment area 18, an interventional device, such as the
interventional instrument catheter 72 including the a
self-expanding stent 30, may be positioned in the area of treatment
18 utilizing the elongated shaft 32 of the emboli-capturing
catheter 16 as a guidewire, again using well-known over-the-wire
techniques. Upon positioning the self-expanding stent 30 at the
treatment area 18, the retractable sheath 80 of the interventional
instrument catheter 72 may be retracted through use of the adapter
82, releasing the self-expanding stent 30 to compress the build-up
of plaque 24 in the treatment area. Any embolic material 12 which
may be released into the blood during the therapeutic procedure may
then be directed with the blood flow through the perfusion openings
42 and through the filter media 50 for filtering thereof, to
capture embolic material 12 which may be released into the blood in
the blood vessel 14 during the interventional procedure. The
perfusion openings 42 are adapted to direct the embolic material 12
into the central lumen 40 and, in cooperation with the filter media
50, to prevent the embolic material 12 from passing therethrough
with the blood for filtering the embolic material 12. The plurality
of inlet openings 44 are adapted to enable embolic material 12 to
pass therethrough into the central lumen 40. The outlet distal
opening 46 in the embodiments of FIGS. 1 and 2, and the outlet
distal openings 48 in the embodiment of FIG. 3, in conjunction with
the filter media 50, are adapted to prevent large and small embolic
material 12 from passing therethrough for filtering thereof.
[0034] The filter media 50 are adapted to capture and filter the
emboli 12. The filter media 52 in the embodiment of FIG. 1 are
adapted to capture and filter the large and small emboli 12. The
filter media 54 in the embodiment of FIG. 2 are staged such that
the large emboli 12 are captured and filtered by the coarse mesh
filter media 56, and the small emboli 12 are captured and filtered
by the fine mesh filter media 58. The filter media 60 in the
embodiment of FIG. 3 are also adapted to capture and filter the
large and small emboli 12. The coarse mesh filter media 64 filter
the large emboli 12, and the fine mesh filter media 62, extending
circumferentially about the coarse mesh filter media 64 and
covering the plurality of outlet distal openings 48, are adapted to
filter the small emboli 12. After the stent 30 is deployed in the
treatment area 18, the interventional instrument catheter 70 may be
withdrawn. Then, after a sufficient time passes to allow any
embolic material 12 released into the blood to be captured by the
filter media 50, the expandable member 40 may be deflated, and the
embolic-capturing catheter 30 along the embolic material 12
captured in the filter media 50 may be withdrawn from the blood
vessel 14, leaving the stent 30 in position therein.
[0035] In the embodiment of the invention illustrated in FIG. 4,
once the system is in place in the patient's vasculature 14, the
expandable member 40 may be used to contract and pin the plaque 24
at the treatment area 18, so as to occlude the blood vessel 14 and
prevent emboli from forming and being released from the treatment
area 18 prior to deploying the filter media 66. The filter media
66, which are adapted to pass through an enlarged lumen 38 in
collapsed form, may then be deployed by projecting the filter media
66 through the distal end 36 of the elongated shaft 32 of the
emboli-capturing catheter 16, into the blood vessel 14 distal to
the treatment area 18, so as to capture embolic material 12 which
may be released into the blood in the blood vessel 14. The
expandable member 40 may then be deflated, with any embolic
material released into the blood upon expansion and deflation of
the expandable member 40 captured by the filter media 66. The
self-expanding stent 30 may then be positioned and deployed, as set
forth above. The deployed filter media 66 may then capture any
further embolic material 12 released into the blood in the blood
vessel 14 upon deployment of the stent 30. After the stent 30 is
deployed in the treatment area 18, the interventional instrument
catheter 72 may be withdrawn. Then, after a sufficient time to
allow any further embolic material 12 released into the blood in
the blood vessel 14 to be captured by the filter media 66, the
filter media 66 may be retracted into the elongated shaft 32 of the
emboli-capturing catheter 16 along with the embolic material 12
captured in the filter media 66, and the emboli-capturing catheter
30 may be withdrawn from the blood vessel 14, leaving the stent 30
in position therein. the filter media 66, and the emboli-capturing
catheter 30 may be withdrawn from the blood vessel 14, leaving the
stent 30 in position therein.
[0036] It should be appreciated that the particular embodiments of
the filter media 50 are capable of being positioned in the blood
vessel 14. However, other forms of filter media 50 may be utilized
with the present invention without departing from the spirit and
scope of the invention. For example, filter media 50 may further be
comprised of other forms of material. Additionally, while the
filter media 50 is shown as in various shapes in the embodiments
herein, it can be formed in any one of a number of different shapes
depending upon the construction desired.
[0037] The catheter assembly 16 of the present invention may be
formed of conventional materials of construction. The catheter body
32 and the inflatable balloon 40 can be made out of relatively
inelastic materials such as polyethylene, polyvinyl chloride,
polyesters and composite materials. The various components may be
joined by suitable adhesives such as acrylonitrile based adhesives
or cyanoacrylate based adhesives. Heat shrinking or heat bonding
may also be employed where appropriate. Plastic-to-plastic or
plastic-to-metal joints can be effected by a suitable acrylonitrile
or cyanoacrylate adhesive. Variations can be made in the
composition of the materials to vary properties as needed.
[0038] In view of the foregoing, it is apparent that the system and
method of the present invention enhances substantially the safety
of performing interventional procedures by significantly reducing
the risks associated with embolic material being created and
released into the patient's bloodstream. Further modifications and
improvements may additionally be made to the system and method
disclosed herein without the departing from the scope of the
invention. Accordingly, it is not intended that the invention be
limited, except as by the appended claims.
* * * * *