U.S. patent application number 14/552708 was filed with the patent office on 2016-11-24 for devices and systems for accessing cardiac tissue.
The applicant listed for this patent is CVDevices, LLC. Invention is credited to Ghassan S. Kassab, Jose A. Navia, SR..
Application Number | 20160339210 14/552708 |
Document ID | / |
Family ID | 38957265 |
Filed Date | 2016-11-24 |
United States Patent
Application |
20160339210 |
Kind Code |
A9 |
Kassab; Ghassan S. ; et
al. |
November 24, 2016 |
DEVICES AND SYSTEMS FOR ACCESSING CARDIAC TISSUE
Abstract
Devices, systems, and methods for accessing the internal and
external tissues of the heart are disclosed. At least some of the
embodiments disclosed herein provide access to the external surface
of the heart through the pericardial space for localized delivery
of substances to the heart tissue. In addition, various disclosed
embodiments provide access to the internal surface of the heart for
aspiration and delivery of substances to a targeted region without
disturbing or interfering with nearby structures or surfaces.
Inventors: |
Kassab; Ghassan S.; (La
Jolla, CA) ; Navia, SR.; Jose A.; (Buenos Aires,
AR) |
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Applicant: |
Name |
City |
State |
Country |
Type |
CVDevices, LLC |
San Diego |
CA |
US |
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Prior
Publication: |
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Document Identifier |
Publication Date |
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US 20150080805 A1 |
March 19, 2015 |
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Family ID: |
38957265 |
Appl. No.: |
14/552708 |
Filed: |
November 25, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12816655 |
Jun 16, 2010 |
8894606 |
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14552708 |
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12305864 |
Dec 19, 2008 |
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PCT/US07/15207 |
Jun 29, 2007 |
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12816655 |
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60817421 |
Jun 30, 2006 |
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60914452 |
Apr 27, 2007 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 25/0084 20130101;
A61B 17/0057 20130101; A61B 17/00491 20130101; A61M 25/0662
20130101; A61M 2025/0004 20130101; A61B 2017/00292 20130101; A61N
1/0592 20130101; A61B 2017/0065 20130101; A61M 2025/0039 20130101;
A61B 2017/00243 20130101; A61M 25/04 20130101; A61B 2017/00606
20130101; A61B 2017/306 20130101; A61M 2210/125 20130101; A61B
2017/00575 20130101; A61M 5/14 20130101; A61B 17/00234 20130101;
A61B 17/30 20130101 |
International
Class: |
A61M 25/04 20060101
A61M025/04; A61M 5/14 20060101 A61M005/14; A61B 17/00 20060101
A61B017/00; A61M 25/00 20060101 A61M025/00 |
Claims
1. An engagement catheter for engaging heart tissue, comprising: an
elongated tube comprising a proximal end, a distal end, and an
internal lumen extending between the proximal end and the distal
end; a vacuum port in communication with the proximal end of the
tube, the vacuum port operatively connected to the internal lumen
and capable of operative connection to a vacuum source; and a
suction port in communication with the internal lumen at or near
the distal end of the tube, the suction port configured to
removably engage a targeted tissue on the interior of a wall of a
heart, such that the suction port is capable of forming a
reversible seal with the wall of the heart when the vacuum source
is operatively attached to the vacuum port; wherein the engagement
catheter is configured for percutaneous intravascular insertion
into a patient through a blood vessel of the patient and further
configured for advancement to the targeted tissue through the blood
vessel; wherein the suction port is configured to removably attach
to the targeted tissue under vacuum applied from the vacuum source
after introduction of a portion of the engagement catheter into the
blood vessel; wherein the engagement catheter is configured so that
at least a portion of the engagement catheter can be retracted
after percutaneous intravascular insertion, while remaining
removably attached to the targeted tissue due to vacuum from the
vacuum source through the first lumen of the engagement catheter
and suction engagement from the suction port, so to locally
increase a distance between the targeted tissue and a pericardium
surrounding the heart; and wherein the engagement catheter is
configured so that when the engagement catheter is used to form the
reversible seal under vacuum through the first lumen using the
suction port, a second device can be delivered through the vacuum
port into the first lumen of the engagement catheter while
maintaining the reversible seal.
2. The engagement catheter of claim 1, forming a system with the
second device.
3. The engagement catheter of claim 1, wherein when the engagement
catheter is used to removably engage the targeted tissue, a
delivery catheter may be inserted into and/or removed from the
internal lumen of the engagement catheter.
4. The engagement catheter of claim 1, wherein the suction port is
configured to removably engage a portion of an atrial wall, an
atrial appendage, a right atrial wall, or a right atrial
appendage.
5. The engagement catheter of claim 1, further comprising: at least
one internal lumen support positioned within the internal lumen and
attached to the tube, the at least one internal lumen support
extending from the distal end of the tube along at least part of a
length of the tube.
6. The engagement catheter of claim 5, wherein the internal lumen
comprises two internal lumens.
7. The engagement catheter of claim 1, further comprising: an
injection channel formed along the length of the tube, the
injection channel having at its distal end at least one opening for
administering a fluid to the targeted tissue, the injection channel
capable of operable attachment to an external fluid source at the
proximal end of the injection channel, such that fluid from the
external fluid source can flow through the injection channel to the
targeted tissue when the external fluid source is operatively
attached to the injection channel.
8. An engagement catheter for use with a vacuum source for engaging
a tissue, the engagement catheter comprising: a first lumen
extending between a proximal end and a distal end; a suction port
located at or near the distal end of the engagement catheter and in
communication with the first lumen of the engagement catheter, the
suction port configured to allow the distal end to removably engage
a surface of a bodily tissue; and a vacuum port located at the
proximal end of the engagement catheter, the vacuum port in
communication with the first lumen of the engagement catheter and
capable of operative connection to a vacuum source; wherein the
engagement catheter is configured for percutaneous intravascular
insertion into a patient through a blood vessel; wherein when a
vacuum source is operatively attached to the vacuum port, the
distal end is capable of forming a reversible seal with the surface
of the bodily tissue; and wherein the engagement catheter is
capable of locally increasing a distance between the bodily tissue
and a second tissue behind the first tissue by retracting the
bodily tissue away from the second tissue while the reversible seal
is formed.
9. The engagement catheter of claim 8, further comprising: a second
lumen extending between the proximal end and the distal end, the
first lumen and the second lumen separated by an inner wall within
the engagement catheter and having a concentric axis; and at least
one internal lumen support positioned within the second lumen and
attached to the inner wall and an outer wall of the engagement
catheter along at least a substantial portion of a longitudinal
length of the engagement catheter.
10. The engagement catheter of claim 8, wherein the engagement
catheter is configured so that when the engagement catheter is used
to form the reversible seal under vacuum through the first lumen
using the suction port, a second device can be delivered through
the vacuum port into the first lumen of the engagement catheter
while maintaining the reversible seal.
11. The engagement catheter of claim 8, wherein the engagement
catheter is configured for advancement to a heart through the blood
vessel.
12. The engagement catheter of claim 11, wherein the second tissue
comprising a pericardium surrounding the heart, and wherein the
engagement catheter is capable of locally increasing a pericardial
space between the bodily tissue and the pericardium.
13. An engagement catheter for engaging mammalian tissue,
comprising: an elongated tube comprising a proximal end, a distal
end, and an internal lumen extending between the proximal end and
the distal end; a vacuum port in communication with the proximal
end of the tube, the vacuum port operatively connected to the
internal lumen and capable of operative connection to a vacuum
source; and a suction port in communication with the internal lumen
at or near the distal end of the tube, the suction port configured
to removably engage a targeted tissue, such that the suction port
is capable of forming a reversible seal with the targeted tissue
when the vacuum source is operatively attached to the vacuum port;
wherein the engagement catheter is configured for percutaneous
intravascular insertion into a patient through a blood vessel;
wherein the suction port is configured to removably attach to the
targeted tissue under vacuum applied from the vacuum source after
introduction of a portion of the engagement catheter into the blood
vessel; wherein the engagement catheter is configured so that at
least a portion of the engagement catheter can be retracted after
percutaneous intravascular insertion, while remaining removably
attached to the targeted tissue due to vacuum from the vacuum
source through the first lumen of the engagement catheter and
suction engagement from the suction port, so to locally increase a
distance between the targeted tissue and a second tissue behind the
bodily tissue; and wherein the engagement catheter is configured so
that when the engagement catheter is used to form the reversible
seal under vacuum through the first lumen using the suction port, a
second device can be delivered through the vacuum port into the
first lumen of the engagement catheter while maintaining the
reversible seal.
14. The engagement catheter of claim 13, forming a system with the
second device.
15. The engagement catheter of claim 13, wherein when the
engagement catheter is used to removably engage the targeted
tissue, a delivery catheter may be inserted into and/or removed
from the internal lumen of the engagement catheter.
16. The engagement catheter of claim 13, wherein the suction port
is configured to removably engage a portion of an atrial wall, an
atrial appendage, a right atrial wall, or a right atrial
appendage.
17. The engagement catheter of claim 13, further comprising: at
least one internal lumen support positioned within the internal
lumen and attached to the tube, the at least one internal lumen
support extending from the distal end of the tube along at least
part of a length of the tube.
18. The engagement catheter of claim 17, wherein the internal lumen
comprises two internal lumens.
19. The engagement catheter of claim 13, further comprising: an
injection channel formed along the length of the tube, the
injection channel having at its distal end at least one opening for
administering a fluid to the targeted tissue, the injection channel
capable of operable attachment to an external fluid source at the
proximal end of the injection channel, such that fluid from the
external fluid source can flow through the injection channel to the
targeted tissue when the external fluid source is operatively
attached to the injection channel.
20. The engagement catheter of claim 13, wherein the engagement
catheter is configured for advancement to a heart through the blood
vessel.
Description
PRIORITY
[0001] This U.S. continuation patent application is related to, and
claims the priority benefit of, U.S. Nonprovisional Patent
Application Ser. No. 12/816,655, filed Jun. 16, 2010 and issued as
U.S. Pat. No. 8,894,606 on Nov. 25, 2014, which is related to,
claims the priority benefit of, and is a U.S. continuation patent
application of, U.S. Nonprovisional Patent Application Ser. No.
12/305,864, filed Dec. 19, 2008, now abandoned, which is related
to, claims the priority benefit of, and is a U.S. national stage
application of, International Patent Application No.
PCT/US2007/015207, filed Jun. 29, 2007, which is related to, and
claims the priority benefit of, U.S. Provisional Patent Application
Ser. No. 60/914,452, filed Apr. 27, 2007, and U.S. Provisional
Patent Application Ser. No. 60/817,421, filed Jun. 30, 2006. The
contents of each of these applications are hereby incorporated by
reference in their entirety into this disclosure.
BACKGROUND
[0002] Ischemic heart disease, or coronary heart disease, kills
more Americans per year than any other single cause. In 2004, one
in every five deaths in the United States resulted from ischemic
heart disease.
[0003] Ischemic heart disease is generally characterized by a
diminished flow of blood to the myocardium and is also often
treated using drug therapy. Although many of the available drugs
may be administered systemically, local drug delivery ("LDD")
directly to the heart can result in higher local drug
concentrations with fewer systemic side effects, thereby leading to
improved therapeutic outcomes.
[0004] Cardiac drugs may be delivered locally via catheter passing
through the blood vessels to the inside of the heart. However,
endoluminal drug delivery has several shortcomings, such as: (1)
inconsistent delivery, (2) low efficiency of localization, and (3)
relatively rapid washout into the circulation.
[0005] To overcome such shortcomings, drugs may be delivered
directly into the pericardial space, which surrounds the external
surface of the heart. The pericardial space is a cavity formed
between the heart and the relatively stiff pericardial sac that
encases the heart. Although the pericardial space is usually quite
small because the pericardial sac and the heart are in such close
contact, a catheter may be used to inject a drug into the
pericardial space for local administration to the myocardial and
coronary tissues. Drug delivery methods that supply the agent to
the heart via the pericardial space offer several advantages over
endoluminal delivery, including: (1) enhanced consistency and (2)
prolonged exposure of the drug to the cardiac tissue.
[0006] In current practice, drugs are delivered into the
pericardial space either by the percutaneous transventricular
method or by the transthoracic approach. The percutaneous
transventricular method involves the controlled penetration of a
catheter through the ventricular myocardium to the pericardial
space. The transthoracic approach involves accessing the
pericardial space from outside the heart using a sheathed needle
with a suction tip to grasp the pericardium, pulling it away from
the myocardium to enlarge the pericardial space, and injecting the
drug into the space with the needle.
[0007] Clinically, the only approved non-surgical means for
accessing the pericardial space include the subxiphoid and the
ultrasound-guided apical and parasternal needle catheter
techniques, and each methods involves a transthoracic approach. In
the subxiphoid method, a sheathed needle with a suction tip is
advanced from a subxiphoid position into the mediastinum under
fluoroscopic guidance. The catheter is positioned onto the anterior
outer surface of the pericardial sac, and the suction tip is used
to grasp the pericardium and pull it away from the heart tissue,
thereby creating additional clearance between the pericardial sac
and the heart. The additional clearance tends to decrease the
likelihood that the myocardium will be inadvertently punctured when
the pericardial sac is pierced.
[0008] Although this technique works well in the normal heart,
there are major limitations in diseased or dilated hearts--the very
hearts for which drug delivery is most needed. When the heart is
enlarged, the pericardial space is significantly smaller and the
risk of puncturing the right ventricle or other cardiac structures
is increased. Additionally, because the pericardium is a very stiff
membrane, the suction on the pericardium provides little
deformation of the pericardium and, therefore, very little
clearance of the pericardium from the heart.
[0009] Thus, there is need for an efficient, easy to use, and
relatively inexpensive technique that can be used to access the
heart for local delivery of therapeutic and diagnostic
substances.
BRIEF SUMMARY
[0010] Various embodiments disclosed herein relate to systems,
devices, and methods for accessing specific tissues of the heart
and for delivering substances to the cardiac tissue. For example,
using certain embodiments, a substance may be delivered to a
specifically targeted area of the interior of a wall of the heart
(i.e., "targeted tissue"). Certain other embodiments provide for
access to the tissue on the external surface of the heart by
delivering a substance to the pericardial space using a
non-surgical, percutaneous route that is both rapid and safe.
Indeed, many of the disclosed embodiments avoid percutaneous
subxiphoid puncture and hence the associated increased risk of
right ventricular lesions, as well as the anterior thoracotomy for
pericardial window procedure.
[0011] At least some of the embodiments disclosed herein include a
system for accessing the tissue of a heart comprising an engagement
catheter having a proximal end, a distal end, and first and second
lumens extending between the proximal end and the distal end. A
vacuum port is located at the proximal end of the engagement
catheter and is operatively connected to the first lumen of the
engagement catheter and capable of operative connection to a vacuum
source. The first lumen of the engagement catheter includes a
suction port located at or near the catheter's distal end, and the
suction port is configured to removably attach to a targeted tissue
on the interior of a wall of the heart. The wall may be an atrial
wall or a wall of the atrial appendage. The suction port is capable
of forming a reversible seal with the targeted tissue when the
vacuum source is operatively attached to the vacuum port, and the
system is capable of enlarging a pericardial space between the
targeted tissue and a pericardial sac that surrounds the heart by
retracting the targeted tissue away from the pericardial sac.
[0012] The system also includes a delivery catheter comprising a
proximal end, a distal end, and a hollow tube extending between the
proximal end and the distal end, and the delivery catheter may be
configured to be inserted into the second lumen of the engagement
catheter. A needle may be located at the distal end of the delivery
catheter, and the needle may include a pressure tip or a needle
wire. In some embodiments, the delivery catheter may include a
first lumen for delivering a fluid to the pericardial space.
Further, the delivery catheter may be configured to fit within the
second lumen of the engagement catheter such that the needle is
positioned to be capable of piercing the targeted tissue when the
suction port is attached to the targeted tissue, and such that,
when the tissue is pierced, access to the pericardial space is
achieved.
[0013] In various embodiments, the engagement catheter also has, in
fluid communication with its second lumen, an injection channel
that is configured to administer a fluid to the targeted tissue.
The system may include a fluid, such as an adhesive, for
administration to the targeted tissue through the injection
channel. The injection channel may be formed along the length of
the engagement catheter, may have at its distal end at least one
opening for administering a fluid to the heart tissue, and may be
capable of operable attachment to an external fluid source at the
proximal end of the injection channel such that fluid from the
external fluid source can flow through the injection channel to the
targeted tissue when the external fluid source is operatively
attached to the injection channel. In some embodiments, the
injection channel is ring-shaped.
[0014] Also disclosed herein are embodiments of an engagement
catheter to be used with a vacuum source in accessing heart tissue.
Such embodiments include an elongated tube comprising a proximal
end, a distal end, an outer wall positioned circumferentially along
the length of the tube, and an inner wall positioned
circumferentially along the length of the tube, wherein the outer
wall and the inner wall form at least one suction channel along the
length of the tube between the outer wall and the inner wall; a
vacuum port in communication with the proximal end of the tube, the
vacuum port being operatively connected to the at least one suction
channel and capable of operative connection to the vacuum source;
and a suction port in communication with the at least one suction
channel at the distal end of the tube. The suction port is
configured to removably attach to targeted tissue on the interior
of a wall of the heart and is capable of forming a reversible seal
with the heart wall when the vacuum source is operatively attached
to the vacuum port. When the suction port is attached to the
targeted tissue, the engagement catheter is capable of enlarging
the pericardial space between the heart and the pericardial
sac.
[0015] Certain embodiments include at least one internal lumen
support positioned within the suction channel and attached to the
outer wall and the inner wall. Each internal lumen support may
extend from the distal end of the tube along at least a substantial
portion of the length of the tube. In embodiments having two
internal lumen supports, the lumen supports form two suction
channels.
[0016] At least some of the embodiments of an engagement catheter
disclosed herein have an injection channel formed along the length
of the tube, the injection channel having at its distal end at
least one opening for administering a fluid to the targeted tissue.
The injection channel is capable of operable attachment to an
external fluid source at the proximal end of the injection channel
such that fluid from the external fluid source can flow through the
injection channel to the heart tissue when the external fluid
source is operatively attached to the injection channel.
[0017] Various embodiments disclosed herein include a delivery
catheter for use in accessing heart tissue. Some delivery catheter
embodiments include an elongated hollow tube comprising a proximal
end, a distal end, a lumen, a needle extending from the distal end
of the tube, and a security notch formed circumferentially around
the needle. The security notch is configured to prevent
over-perforation of the needle when piercing a wall of the heart
into the pericardial space. The tube of some embodiments of
delivery catheter further includes one or more openings for
administering a fluid to an external surface of the heart located
in the pericardial space, such that the at least one opening is in
fluid communication with the lumen of the tube. In at least some
embodiments, an elongated guide wire may be placed inside the lumen
of the tube and inserted into the pericardial space.
[0018] Also disclosed herein are various methods for accessing
heart tissue. Certain embodiments include the steps of providing a
system as disclosed herein; inserting an engagement catheter into
the body such that the distal end of the engagement catheter is
positioned inside the heart and the suction port is in contact with
the interior of a wall of the heart; operatively connecting a
vacuum source to the vacuum port such that the suction port is
reversibly attached to a targeted tissue on the interior of a wall
of the heart; inserting the delivery catheter into the second lumen
of the engagement catheter; piercing the targeted tissue with the
needle; and administering a substance into the pericardial space.
In some embodiments, the method also includes the step of
administering a substance to the targeted tissue after withdrawal
of the needle, and the substance may include an adhesive for
sealing a puncture wound in the targeted tissue.
[0019] Certain other embodiments include the steps of extending
into a blood vessel an elongated hollow tube having a proximal end,
a distal end, and at least one lumen, such that the distal end of
the tube is in contact with the interior of a wall of the heart;
aspirating a targeted tissue on the interior of a wall of the heart
such that the wall of the heart is retracted away from a
pericardial sac surrounding the heart to enlarge a pericardial
space between the pericardial sac and the wall of the heart;
delivering a fluid onto the targeted tissue; and removing the
elongated tube from the body. Such embodiments may further include
the steps of inserting through a lumen of the elongated tube a
delivery catheter having a proximal end, a distal end, and a needle
located at the distal end, such that the needle is located within
the heart; inserting the needle into the targeted tissue on the
interior of the wall of the heart; and injecting a fluid into the
pericardial space such that the fluid contacts the exterior of the
heart within the pericardial space. In at least some embodiments,
the needle is withdrawn after puncture, and the distal end of a
guide wire is inserted through the lumen of the delivery catheter
and into the pericardial space. The delivery catheter may then be
inserted into the pericardial space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1A shows an embodiment of an engagement catheter and an
embodiment of a delivery catheter as disclosed herein;
[0021] FIG. 1B shows a percutaneous intravascular pericardial
delivery using another embodiment of an engagement catheter and
another embodiment of a delivery catheter as disclosed herein;
[0022] FIG. 2A shows a percutaneous intravascular technique for
accessing the pericardial space through a right atrial wall or
atrial appendage using the engagement and delivery catheters shown
in FIG. 1A;
[0023] FIG. 2B shows the embodiment of an engagement catheter shown
in FIG. 2A;
[0024] FIG. 2C shows another view of the distal end of the
engagement catheter embodiment shown in FIGS. 2A and 2B;
[0025] FIG. 3A shows removal of an embodiment of a catheter as
disclosed herein;
[0026] FIG. 3B shows the resealing of a puncture according to an
embodiment as disclosed herein;
[0027] FIG. 4A to 4C show a closure of a hole in the atrial wall
using an embodiment as disclosed herein;
[0028] FIG. 5A shows an embodiment of an engagement catheter as
disclosed herein;
[0029] FIG. 5B shows a cross-sectional view of the proximal end of
the engagement catheter shown in FIG. 5A;
[0030] FIG. 5C shows a cross-sectional view of the distal end of
the engagement catheter shown in FIG. 5A;
[0031] FIG. 5D shows the engagement catheter shown in FIG. 5A
approaching a heart wall from inside of the heart;
[0032] FIG. 6A shows an embodiment of a delivery catheter as
disclosed herein;
[0033] FIG. 6B shows a close-up view of the needle shown in FIG.
6A; and
[0034] FIG. 6C shows a cross-sectional view of the needle shown in
FIGS. 6A and 6B.
DETAILED DESCRIPTION
[0035] For the purposes of promoting an understanding of the
principles of the present disclosure, reference will now be made to
the embodiments illustrated in the drawings, and specific language
will be used to describe the same. It will nevertheless be
understood that no limitation of the scope of this disclosure is
thereby intended.
[0036] The disclosed embodiments include devices, systems, and
methods useful for accessing various tissues of the heart from
inside the heart. For example, various embodiments provide for
percutaneous, intravascular access into the pericardial space
through an atrial wall or the wall of an atrial appendage. In at
least some embodiments, the heart wall is aspirated and retracted
from the pericardial sac to increase the pericardial space between
the heart and the sac and thereby facilitate access into the
space.
[0037] Unlike the relatively stiff pericardial sac, the atrial wall
and atrial appendage are rather soft and deformable. Hence, suction
of the atrial wall or atrial appendage can provide significantly
more clearance of the cardiac structure from the pericardium as
compared to suction of the pericardium. Furthermore, navigation
from the intravascular region (inside of the heart) provides more
certainty of position of vital cardiac structures than does
intrathoracic access (outside of the heart).
[0038] Access to the pericardial space may be used for
identification of diagnostic markers in the pericardial fluid; for
pericardiocentesis; and for administration of therapeutic factors
with angiogenic, myogenic, and antiarrhythmic potential. In
addition, epicardial pacing leads may be delivered via the
pericardial space, and an ablation catheter may be used on the
epicardial tissue from the pericardial space.
[0039] In the embodiment of the catheter system shown in FIG. 1A,
catheter system 10 includes an engagement catheter 20, a delivery
catheter 30, and a needle 40. Although each of engagement catheter
20, delivery catheter 30, and needle 40 has a proximal end and a
distal end, FIG. 1A shows only the distal end. Engagement catheter
20 has a lumen through which delivery catheter 30 has been
inserted, and delivery catheter 30 has a lumen through which needle
40 has been inserted. Delivery catheter 30 also has a number of
openings 50 that can be used to transmit fluid from the lumen of
the catheter to the heart tissue in close proximity to the distal
end of the catheter.
[0040] As shown in more detail in FIGS. 2A, 2B, and 2C, engagement
catheter 20 includes a vacuum channel 60 used for suction of a
targeted tissue 65 in the heart and an injection channel 70 used
for infusion of substances to targeted tissue 65, including, for
example, a biological or non-biological degradable adhesive. As is
shown in FIGS. 2B and 2C, injection channel 70 is ring-shaped,
which tends to provide relatively even dispersal of the infused
substance over the targeted tissue, but other shapes of injection
channels may be suitable. A syringe 80 is attached to injection
channel 70 for delivery of the appropriate substances to injection
channel 70, and a syringe 90 is attached to vacuum channel 60
through a vacuum port (not shown) at the proximal end of engagement
catheter 20 to provide appropriate suction through vacuum channel
60. At the distal end of engagement catheter 20, a suction port 95
is attached to vacuum channel 60 for contacting targeted tissue 65,
such that suction port 95 surrounds targeted tissue 65, which is
thereby encompassed within the circumference of suction port 95.
Although syringe 90 is shown in FIG. 2B as the vacuum source
providing suction for engagement catheter 20, other types of vacuum
sources may be used, such as a controlled vacuum system providing
specific suction pressures. Similarly, syringe 80 serves as the
external fluid source in the embodiment shown in FIG. 2B, but other
external fluid sources may be used.
[0041] A route of entry for use of various embodiments disclosed
herein is through the jugular or femoral vein to the superior or
inferior vena cavae, respectively, to the right atrial wall or
atrial appendage (percutaneously) to the pericardial sac (through
puncture).
[0042] Referring now to FIG. 1B, an engagement catheter 100 is
placed via standard approach into the jugular or femoral vein. The
catheter, which may be 4 or 5 Fr., is positioned under fluoroscopic
or echocardiographic guidance into the right atrial appendage 110.
Suction is initiated to aspirate a portion of atrial appendage 110
away from the pericardial sac 120 that surrounds the heart. As
explained herein, aspiration of the heart tissue is evidenced when
no blood can be pulled back through engagement catheter 100 and, if
suction pressure is being measured, when the suction pressure
gradually increases. A delivery catheter 130 is then inserted
through a lumen of engagement catheter 100. A small perforation can
be made in the aspirated atrial appendage 110 with a needle such as
needle 40, as shown in FIGS. 1A and 2A. A guide wire (not shown)
can then be advanced through delivery catheter 130 into the
pericardial space to secure the point of entry 125 through the
atrial appendage and guide further insertion of delivery catheter
130 or another catheter. Fluoroscopy or echocardiogram can be used
to confirm the position of the catheter in the pericardial space.
Alternatively, a pressure tip needle can sense the pressure and
measure the pressure change from the atrium (about 10 mmHg) to the
pericardial space (about 2 mmHg). This is particularly helpful for
transeptal access where puncture of arterial structures (e.g., the
aorta) can be diagnosed and sealed with an adhesive, as described
in more detail below.
[0043] Although aspiration of the atrial wall or the atrial
appendage retracts the wall or appendage from the pericardial sac
to create additional pericardial space, CO2 gas can be delivered
through a catheter, such as delivery catheter 130, into the
pericardial space to create additional space between the
pericardial sac and the heart surface.
[0044] Referring now to FIG. 3A, the catheter system shown in FIG.
1B is retrieved by pull back through the route of entry. However,
the puncture of the targeted tissue in the heart (e.g., the right
atrial appendage as shown in FIG. 3A) may be sealed upon withdrawal
of the catheter, which prevents bleeding into the pericardial
space. The retrieval of the catheter may be combined with a sealing
of the tissue in one of several ways: (1) release of a tissue
adhesive or polymer 75 via injection channel 70 to seal off the
puncture hole, as shown in FIG. 3B; (2) release of an inner clip or
mechanical stitch to close off the hole from the inside of the
cavity of the heart, as discussed herein; or (3) mechanical closure
of the heart with a sandwich type mechanical device that approaches
the hole from both sides of the wall (see FIGS. 4A, 4B, and 4C). In
other words, closure may be accomplished by using, for example, a
biodegradable adhesive material (e.g., fibrin glue or
cyanomethacrylate), a magnetic system, or an umbrella-shaped
nitinol stent. An example of the closure of a hole in the atrium is
shown in FIG. 3B. Engagement catheter 20 is attached to targeted
tissue 95 using suction through suction port 60. Tissue adhesive 75
is injected through injection channel 70 to coat and seal the
puncture wound in targeted tissue 95. Engagement catheter 20 is
then withdrawn, leaving a plug of tissue adhesive 75 attached to
the atrial wall or atrial appendage.
[0045] Other examples for sealing the puncture wound in the atrial
wall or appendage are shown in FIGS. 4A, 4B, and 4C. A
sandwich-type closure member, having an external cover 610 and an
internal cover 620, is inserted through the lumen of engagement
catheter 600, which is attached to the targeted tissue of an atrial
wall 630. Each of external and internal covers 610 and 620 is
similar to an umbrella in that it can be inserted through a
catheter in its folded configuration and expanded once it is
outside of the catheter. As shown in FIG. 4A, external cover 610 is
deployed (in its expanded configuration) on the outside of the
atrial wall to seal a puncture wound in the targeted tissue.
Internal cover 620 is delivered through engagement catheter 600 (in
its folded configuration), as shown in FIGS. 4A and 4B. Once
internal cover 620 is in position on the inside of atrial wall 630
at the targeted tissue, internal cover 620 is deployed to help seal
the puncture wound in the targeted tissue (see FIG. 4C). Engagement
catheter 600 then releases its grip on the targeted tissue and is
withdrawn, leaving the sandwich-type closure to seal the puncture
wound, as shown in FIG. 4C. External cover 610 and internal cover
620 may be held in place using adhesion or magnetic forces.
[0046] FIGS. 5A, 5B, 5C, and 5D show another embodiment of an
engagement catheter as disclosed herein. Engagement catheter 700 is
an elongated tube having a proximal end 710 and a distal end 720,
as well as two lumens 730, 740 extending between proximal end 710
and distal end 720. Lumens 730, 740 are formed by concentric inner
wall 750 and outer wall 760, as particularly shown in FIGS. 5B and
5C. At proximal end 710, engagement catheter 700 includes a vacuum
port 770, which is attached to lumen 730 so that a vacuum source
can be attached to vacuum port 770 to create suction in lumen 730,
thereby forming a suction channel. At distal end 720 of catheter
700, a suction port 780 is attached to lumen 730 so that suction
port 780 can be placed in contact with heart tissue 775 (see FIG.
5D) for aspirating the tissue, thereby forming a vacuum seal
between suction port 780 and tissue 775 when the vacuum source is
attached and engaged. The vacuum seal enables suction port 780 to
grip, stabilize, and retract tissue 775. For example, attaching a
suction port to an interior atrial wall using a vacuum source
enables the suction port to retract the atrial wall from the
pericardial sac surrounding the heart, which enlarges the
pericardial space between the atrial wall and the pericardial
sac.
[0047] As shown in FIG. 5C, two internal lumen supports 810, 820
are located within lumen 730 and are attached to inner wall 750 and
outer wall 760 to provide support to the walls. These lumen
supports divide lumen 730 into two suction channels. Although
internal lumen supports 810, 820 extend from distal end 720 of
catheter 700 along a substantial portion of the length of catheter
700, internal lumen supports 810, 820 may or may not span the
entire length of catheter 700. Indeed, as shown in FIGS. 5A, 5B,
and 5C, internal lumen supports 810, 820 do not extend to proximal
end 710 to ensure that the suction from the external vacuum source
is distributed relatively evenly around the circumference of
catheter 700. Although the embodiment shown in FIG. 5C includes two
internal lumen supports, other embodiments may have just one
internal support or even three or more such supports.
[0048] FIG. 5D shows engagement catheter 700 approaching heart
tissue 775 for attachment thereto. It is important for the
clinician performing the procedure to know when the suction port
has engaged the tissue of the atrial wall or the atrial appendage.
For example, in reference to FIG. 5D, it is clear that suction port
780 has not fully engaged tissue 775 such that a seal is formed.
However, because suction port 780 is not usually seen during the
procedure, the clinician may determine when the proper vacuum seal
between the atrial tissue and the suction port has been made by
monitoring the amount of blood that is aspirated, by monitoring the
suction pressure with a pressure sensor/regulator, or both. For
example, as engagement catheter 700 approaches the atrial wall
tissue (such as tissue 775) and is approximately in position, the
suction can be activated through lumen 730. A certain level of
suction (e.g., 10 mmHg) can be imposed and measured with a pressure
sensor/regulator. As long as catheter 700 does not engage the wall,
some blood will be aspirated into the catheter and the suction
pressure will remain the same. However, when catheter 700 engages
or attaches to the wall of the heart (depicted as tissue 775 in
FIG. 5D), minimal blood is aspirated and the suction pressure will
start to gradually increase. Each of these signs can alert the
clinician (through alarm or other means) as an indication of
engagement. The pressure regulator is then able to maintain the
suction pressure at a preset value to prevent over-suction of the
tissue.
[0049] An engagement catheter, such as engagement catheter 700, may
be configured to deliver a fluid or other substance to tissue on
the inside of a wall of the heart, including an atrial wall or a
ventricle wall. For example, lumen 740 shown in FIGS. 5A and 5C
includes an injection channel 790 at distal end 720. Injection
channel 790 dispenses to the targeted tissue a substance flowing
through lumen 740. As shown in FIG. 5D, injection channel 790 is
the distal end of lumen 740. However, in other embodiments, the
injection channel may be ring-shaped (see FIG. 2C) or have some
other suitable configuration.
[0050] Substances that can be locally administered with an
engagement catheter include preparations for gene or cell therapy,
drugs, and adhesives that are safe for use in the heart. The
proximal end of lumen 740 has a fluid port 800, which is capable of
attachment to an external fluid source for supply of the fluid to
be delivered to the targeted tissue. Indeed, after withdrawal of a
needle from the targeted tissue, as discussed herein, an adhesive
may be administered to the targeted tissue by the engagement
catheter for sealing the puncture wound left by the needle
withdrawn from the targeted tissue.
[0051] Referring now to FIGS. 6A, 6B, and 6C, there is shown a
delivery catheter 850 comprising an elongated hollow tube 880
having a proximal end 860, a distal end 870, and a lumen 885 along
the length of the catheter. Extending from distal end 870 is a
hollow needle 890 in communication with lumen 885. Needle 890 is
attached to distal end 870 in the embodiment of FIGS. 6A, 6B, and
6C, but, in other embodiments, the needle may be removably attached
to, or otherwise located at, the distal end of the catheter (see
FIG. 1A). In the embodiment shown in FIGS. 6A, 6B, and 6C, as in
certain other embodiments having an attached needle, the junction
(i.e., site of attachment) between hollow tube 880 and needle 890
forms a security notch 910 circumferentially around needle 890 to
prevent needle 890 from over-perforation. Thus, when a clinician
inserts needle 890 through an atrial wall to gain access to the
pericardial space, the clinician will not, under normal conditions,
unintentionally perforate the pericardial sac with needle 890
because the larger diameter of hollow tube 880 (as compared to that
of needle 890) at security notch 910 hinders further needle
insertion. Although security notch 910 is formed by the junction of
hollow tube 880 and needle 890 in the embodiment shown in FIGS. 6A,
6B, and 6C, other embodiments may have a security notch that is
configured differently. For example, a security notch may include a
band, ring, or similar device that is attached to the needle a
suitable distance from the tip of the needle. Like security notch
910, other security notch embodiments hinder insertion of the
needle past the notch itself by presenting a larger profile than
the profile of the needle such that the notch does not easily enter
the hole in the tissue caused by entry of the needle.
[0052] It is useful for the clinician performing the procedure to
know when the needle has punctured the atrial tissue. This can be
done in several ways. For example, the delivery catheter can be
connected to a pressure transducer to measure pressure at the tip
of the needle. Because the pressure is lower and much less
pulsatile in the pericardial space than in the atrium, the
clinician can recognize immediately when the needle passes through
the atrial tissue into the pericardial space.
[0053] Alternatively, as shown in FIG. 6B, needle 890 may be
connected to a strain gauge 915 as part of the catheter assembly.
When needle 890 contacts tissue (not shown), needle 890 will be
deformed. The deformation will be transmitted to strain gauge 915
and an electrical signal will reflect the deformation (through a
classical wheatstone bridge), thereby alerting the clinician. Such
confirmation of the puncture of the wall can prevent over-puncture
and can provide additional control of the procedure.
[0054] In some embodiments, a delivery catheter, such as catheter
850 shown in FIGS. 6A, 6B, and 6C, is used with an engagement
catheter, such as catheter 700 shown in FIGS. 5A, 5B, 5C, and 5D,
to gain access to the pericardial space between the heart wall and
the pericardial sac. For example, engagement catheter 700 may be
inserted into the vascular system and advanced such that the distal
end of the engagement catheter is within the atrium. The engagement
catheter may be attached to the targeted tissue on the interior of
a wall of the atrium using a suction port as disclosed herein. A
standard guide wire may be inserted through the lumen of the
delivery catheter as the delivery catheter is inserted through the
inner lumen of the engagement catheter, such as lumen 740 shown in
FIGS. 5B and 5C. Use of the guide wire enables more effective
navigation of the delivery catheter 850 and prevents the needle 890
from damaging the inner wall 750 of the engagement catheter 700.
When the tip of the delivery catheter with the protruding guide
wire reaches the atrium, the wire is pulled back, and the needle is
pushed forward to perforate the targeted tissue. The guide wire is
then advanced through the perforation into the pericardial space,
providing access to the pericardial space through the atrial
wall.
[0055] Referring again to FIGS. 6A, 6B, and 6C, lumen 885 of
delivery catheter 850 may be used for delivering fluid into the
pericardial space after needle 890 is inserted through the atrial
wall or the atrial appendage. After puncture of the wall or
appendage, a guide wire (not shown) may be inserted through needle
lumen 900 into the pericardial space to maintain access through the
atrial wall or appendage. Fluid may then be introduced to the
pericardial space in a number of ways. For example, after the
needle punctures the atrial wall or appendage, the needle is
generally withdrawn. If the needle is permanently attached to the
delivery catheter, as in the embodiment shown in FIGS. 6A and 6B,
then delivery catheter 850 would be withdrawn and another delivery
catheter (without an attached needle) would be introduced over the
guide wire into the pericardial space. Fluid may then be introduced
into the pericardial space through the lumen of the second delivery
catheter.
[0056] In some embodiments, however, only a single delivery
catheter is used. In such embodiments, the needle is not attached
to the delivery catheter, but instead may be a needle wire (see
FIG. 1A). In such embodiments, the needle is withdrawn through the
lumen of the delivery catheter, and the delivery catheter may be
inserted over the guide wire into the pericardial space. Fluid is
then introduced into the pericardial space through the lumen of the
delivery catheter.
[0057] The various embodiments disclosed herein may be used by
clinicians, for example: (1) to deliver genes, cells, drugs, etc.;
(2) to provide catheter access for epicardial stimulation; (3) to
evacuate fluids acutely (e.g., in cases of pericardial tamponade)
or chronically (e.g., to alleviate effusion caused by chronic renal
disease, cancer, etc.); (4) to perform transeptal puncture and
delivery of a catheter through the left atrial appendage for
electrophysiological therapy, biopsy, etc.; (5) to deliver a
magnetic glue or ring through the right atrial appendage to the
aortic root to hold a percutaneous aortic valve in place; (6) to
deliver a catheter for tissue ablation, e.g., to the pulmonary
veins, or right atrial and epicardial surface of the heart for
atrial and ventricular arrhythmias; (7) to deliver and place
epicardial, right atrial, and right and left ventricle pacing
leads; (8) to occlude the left atrial appendage through
percutaneous approach; and (9) to visualize the pericardial space
with endo-camera or scope to navigate the epicardial surface of the
heart for therapeutic delivery, diagnosis, lead placement, mapping,
etc. Many other applications, not explicitly listed here, are also
possible and within the scope of the present disclosure.
[0058] While various embodiments of devices for accessing the
pericardial space surrounding the heart have been described in
considerable detail herein, the embodiments are merely offered by
way of non-limiting examples of the disclosure described herein. It
will therefore be understood that various changes and modifications
may be made, and equivalents may be substituted for elements
thereof, without departing from the scope of the disclosure.
Indeed, this disclosure is not intended to be exhaustive or to
limit the scope of the disclosure.
[0059] Further, in describing representative embodiments, the
disclosure may have presented a method and/or process as a
particular sequence of steps. However, to the extent that the
method or process does not rely on the particular order of steps
set forth herein, the method or process should not be limited to
the particular sequence of steps described. Other sequences of
steps may be possible. Therefore, the particular order of the steps
disclosed herein should not be construed as limitations of the
present disclosure. In addition, disclosure directed to a method
and/or process should not be limited to the performance of their
steps in the order written. Such sequences may be varied and still
remain within the scope of the present disclosure.
* * * * *