U.S. patent application number 10/124606 was filed with the patent office on 2002-11-14 for method of cerebral embolic protection employing an aortic flow divider.
Invention is credited to Macoviak, John A., Samson, Wilfred J..
Application Number | 20020169437 10/124606 |
Document ID | / |
Family ID | 26814672 |
Filed Date | 2002-11-14 |
United States Patent
Application |
20020169437 |
Kind Code |
A1 |
Macoviak, John A. ; et
al. |
November 14, 2002 |
Method of cerebral embolic protection employing an aortic flow
divider
Abstract
The invention is a catheter with a fluid flow divider positioned
near the distal end of the catheter for dividing a first lumen into
two channels at a point where a second lumen branches from the
first lumen, and for selectively perfusing the branch lumen. The
invention is particularly suited for use in the aortic arch. The
fluid flow divider may comprise one or more inflatable chambers or
one or more deployable shrouds comprising a plurality of arms with
a webbing extending between adjacent arms. The inflatable chambers
may be relatively noncompliant or they may be compliant, exhibiting
elastic behavior after initial inflation, to closely fit the aortic
lumen size and curvature. The catheter may further include one or
more additional or auxiliary flow control members located upstream
or downstream from the fluid flow divider to further segment the
patient's circulatory system for selective perfusion to different
organ systems within the body or to assist in anchoring the
catheter in a desired position.
Inventors: |
Macoviak, John A.; (La
Jolla, CA) ; Samson, Wilfred J.; (Saratoga,
CA) |
Correspondence
Address: |
Gunther Hanke
Fulwider Patton Lee & Utecht
P.O.Box 22615
Long Beach
CA
90801-5615
US
|
Family ID: |
26814672 |
Appl. No.: |
10/124606 |
Filed: |
April 16, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10124606 |
Apr 16, 2002 |
|
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|
09378676 |
Aug 20, 1999 |
|
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6371935 |
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60116836 |
Jan 22, 1999 |
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Current U.S.
Class: |
604/509 ;
604/102.03 |
Current CPC
Class: |
A61M 2025/0073 20130101;
A61B 17/12136 20130101; A61M 25/007 20130101; A61M 2025/1072
20130101; A61B 17/12109 20130101; A61M 25/0067 20130101; A61B
17/12036 20130101; A61B 2017/1205 20130101; A61M 2025/0037
20130101; A61M 2025/1095 20130101; A61B 17/12131 20130101; A61M
25/1002 20130101; A61B 17/12045 20130101 |
Class at
Publication: |
604/509 ;
604/102.03 |
International
Class: |
A61M 031/00 |
Claims
What is claimed is:
1. A method of cerebral embolic protection comprising deploying a
fluid flow divider within a patient's aortic arch lumen and
dividing aortic blood flow into at least two channels, including a
first channel in fluid communication with the patient's aortic arch
branch vessels and a second channel in fluid communication with the
patient's descending aorta.
2. The method of cerebral embolic protection of claim 1, further
comprising perfusing the first channel with a fluid.
3. The method of cerebral embolic protection of claim 1, further
comprising perfusing the second channel with a fluid.
4. The method of cerebral embolic protection of claim 1, further
comprising perfusing the first channel with a first fluid and
perfusing the second channel with a second fluid.
5. The method of cerebral embolic protection of claim 1, further
comprising occluding the lumen of the ascending aorta upstream of
the fluid flow divider.
6. The method of cerebral embolic protection of claim 5, further
comprising infusing a cardioplegic agent into the root of the
patient's ascending aorta to arrest the patient's heart.
7. The method of cerebral embolic protection of claim 1, further
comprising inflating an occlusion balloon to occlude the lumen of
the ascending aorta upstream of the fluid flow divider.
8. The method of cerebral embolic protection of claim 1, further
comprising inserting the fluid flow divider into the patient's
aortic arch lumen via an aortotomy incision.
9. The method of cerebral embolic protection of claim 1, further
comprising inserting the fluid flow divider into the patient's
aortic arch lumen via a peripheral artery insertion site.
10. The method of cerebral embolic protection of claim 1, wherein
the fluid flow divider is deployed within the patient's aortic arch
lumen by inflating an inflatable chamber within the fluid flow
divider.
11. The method of cerebral embolic protection of claim 1, wherein
the fluid flow divider is mounted on a catheter shaft and the
method further comprises perfusing the first channel with a first
fluid through a first lumen within the catheter shaft.
12. The method of cerebral embolic protection of claim 11, further
comprising perfusing the second channel with a second fluid through
a second lumen within the catheter shaft.
13. The method of cerebral embolic protection of claim 11, further
comprising inflating an occlusion balloon mounted on the catheter
shaft to occlude the lumen of the ascending aorta upstream of the
fluid flow divider
14. The method of cerebral embolic protection of claim 1, wherein
the fluid flow divider is deployed from within a catheter
shaft.
15. The method of cerebral embolic protection of claim 1, wherein
the fluid flow divider is deployed using a deployment wire.
16. The method of cerebral embolic protection of claim 1, wherein
the fluid flow divider is deployed by a plurality of mechanically
actuated arms.
17. The method of cerebral embolic protection of claim 1, further
comprising perfusing the first channel with hypothermic oxygenated
blood.
18. The method of cerebral embolic protection of claim 1, further
comprising perfusing the first channel with fluid at a pressure and
flow rate to prevent backflow of fluid from the second channel into
the first channel.
Description
CROSS REFERENCE TO OTHER PATENT APPLICATIONS
[0001] This patent application is a divisional of U.S. patent
application Ser. No. 09/378,676, filed Aug. 20, 1999, now U.S. Pat.
No. 6,371,935, which claims the benefit of U.S. Provisional Patent
Application No. 60/116,836 filed Jan. 22, 1999, the specifications
of which are hereby incorporated by reference in their
entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a catheter system that reduces the
volume of embolic material, which may be knocked loose from an
artery wall or the wall of a chamber of the heart as a result of a
medical procedure, from entering a selected oxygenated blood
carrying artery system. More specifically, the invention relates to
a catheter for isolating and perfusing a segment of a patient's
cardiovascular system and for directing circulatory flow around the
isolated segment. More particularly, it relates to an apparatus for
deployment within a patient's aortic arch and to methods for
selectively perfusing the arch vessels with a fluid, while
directing blood flow within the aortic lumen past the isolated arch
vessels.
BACKGROUND OF THE INVENTION
[0003] In the field of cardiovascular surgery, it has been common
practice for surgeons to perform a sternotomy to expose the body
cavity in the thorax region, wherein retractors are employed to
provide the necessary access to internal structures to perform the
necessary medical procedures.
[0004] Depending on the medical procedure to be performed, it has
often been necessary to arrest heart activity for some period of
time during the procedure. The blood is then diverted through a
cardiopulmonary bypass pump in order to maintain sufficient
oxygenated blood flow to the body.
[0005] Procedures performed as described above cause significant
trauma to the body due to the method of entry into the thorax
region, and the cessation of heart activity. Recent trends in the
development of surgical devices have been toward the use of less
invasive techniques, so that operations cause less extensive
trauma. Furthermore, there has been a trend toward reducing the
amount of time the heart is stopped, or eliminating the step of
stopping the heart.
[0006] One major disadvantage to any procedure performed on the
heart or on major arteries associated with the heart, even for less
invasive procedures, is that embolic material may be knocked loose
from arterial walls, heart valves, or from the interior walls of
the chambers of the heart, and pumped to the brain, where the
resulting blockages may cause neurological damage.
[0007] Cardiopulmonary bypass pumps are frequently used to pump
blood in the patient while the heart is stopped during surgery, and
bypass pumps generally include a filter mechanism to trap embolic
material from the blood before the oxygenated blood is returned to
the body. However, when the heart is started embolic material from
within the heart may be pumped to the brain. Aortic perfusion
shunts, as described in commonly owned and copending U.S. patent
application Ser. No. 09/212,580, filed Dec. 15, 1998, claiming the
benefit of provisional application Ser. No. 60/069,470, filed Dec.
15, 1997, hereby incorporated in its entirety, have been developed
that allow the blood from the heart to perfuse the body, while
providing separate perfusion of the arch vessels. The aortic
perfusion shunts described represent a significant step forward in
protection against cerebral embolization, however, there remains a
tremendous need for further improvements in devices and methods for
protecting a patient against the potential of cerebral
embolization.
[0008] What is needed is a catheter device for use in minimally
invasive medical procedures and for standard open chest surgery
that is simple and relatively inexpensive and that is capable of
isolating the circulation of the arch vessels, while still allowing
the heart to perform the function of perfusing the body of the
patient.
SUMMARY OF THE INVENTION
[0009] Accordingly, the invention is a catheter with a fluid flow
control member called a deflector or a fluid flow divider
positioned near the distal end of the catheter for dividing a first
lumen into two channels near a point where a second lumen branches
from the first lumen, and for perfusing the branch lumen. The
invention will be described more specifically herein relating to an
aortic catheter having a divider positioned in the aortic arch
proximate the arch vessels.
[0010] The flow divider may be formed in a variety of
configurations. In general the flow divider will have an undeployed
or collapsed state and an expanded or deployed state. The flow
divider may be deployed from an exterior surface of the catheter
shaft, or it may be deployed from within a lumen in the catheter
shaft. In embodiments wherein the flow divider is coupled to an
exterior surface, the flow divider will preferably have an
undeployed state wherein the flow divider is contained in a
relatively small volume around the circumference of the distal end
(nearest the heart) of the catheter, having an exterior
circumference that is preferably not significantly larger than the
exterior circumference of the catheter. In embodiments wherein the
flow divider is deployed from within the catheter, the flow divider
preferably has an undeployed state that is sized and configured for
storage within a lumen in the catheter. In both configurations, the
catheter will generally have a deployed state in which the length
and width of the flow divider is sufficient to divide blood flow in
the aorta in the vicinity of the ostia of the arch vessels.
[0011] The flow divider may comprise one or more inflatable
chambers or one or more selectively deployable shrouds. The
inflatable chambers may be relatively non-compliant or they may be
compliant, exhibiting elastic behavior after initial inflation to
closely fit the aortic lumen size and curvature.
[0012] The catheter may further include one or more additional or
auxiliary flow control members located upstream or downstream from
the flow divider to further segment the patient's circulatory
system for selective perfusion to different organ systems within
the body or to assist in anchoring the catheter in a desired
position. These auxiliary flow control members may comprise
inflatable balloons or selectively deployable external catheter
valves. The anchoring members may be inflatable balloons or other
anchoring structures that provide sufficient force or friction to
prevent the catheter from drifting from a selected position within
the aorta.
[0013] In a preferred embodiment, the catheter shaft includes at
least three lumens, one lumen for inflating or otherwise deploying
the flow divider, a second for perfusion of the arch vessels, and a
third guidewire lumen. In alternate embodiments, additional lumens
may be included for deploying the auxiliary flow control members,
and for measuring the pressure at desired locations within the
aorta. The catheter may be configured for retrograde deployment via
a peripheral artery, such as the femoral artery, or it may be
configured for antegrade deployment via an aortotomy incision or
direct puncture in the ascending aorta.
[0014] Methods according to the present invention are described
using the aortic catheter for occluding and compartmentalizing or
partitioning the patient's aortic lumen and for performing
selective filtered aortic perfusion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a bottom view of a first embodiment of the
aortic catheter of the invention configured for retrograde
deployment via a peripheral artery access point, such as the
femoral artery.
[0016] FIG. 2 shows a side view of the catheter of FIG. 1, showing
the divider in a collapsed state.
[0017] FIG. 3 shows a cross section of the aortic catheter of FIG.
1 taken along line 3-3 in FIG. 1.
[0018] FIG. 4 shows a top view of the catheter of FIG. 1 with the
flow divider deployed.
[0019] FIG. 5 shows a perspective view of the distal region of the
catheter of FIG. 1 deployed within an aortic arch.
[0020] FIG. 6 shows a side view of the catheter of FIG. 5 deployed
within an aortic arch.
[0021] FIG. 7 shows a lateral cross section of the aortic lumen and
of the catheter of FIG. 6 taken along line 7-7.
[0022] FIG. 8 shows an alternate embodiment of the catheter of FIG.
7, with the flow divider curved in a direction opposite that shown
in FIG. 7.
[0023] FIG. 9 shows an embodiment of the catheter of the invention
wherein a distal end of the catheter extends through the divider
and beyond the end of the divider.
[0024] FIG. 10 shows an embodiment of the catheter of the invention
wherein the catheter shaft extends below the divider, then above
the divider, and then below the divider again, at different points
along the catheter.
[0025] FIG. 11 shows a side view of the catheter of FIG. 10
deployed within the aortic arch.
[0026] FIG. 12 shows a catheter similar to the catheter of FIG. 10,
but with the divider periphery concave on its upper surface.
[0027] FIG. 13 shows a perspective view of an embodiment of the
catheter of the invention including a deployed auxiliary flow
control member positioned between the flow divider and the distal
end of the catheter.
[0028] FIG. 14 shows a perspective view of the catheter of FIG. 13
with the auxiliary flow control member partially collapsed.
[0029] FIG. 15 shows an embodiment of the catheter of the invention
configured for antegrade deployment.
[0030] FIG. 16 shows another embodiment of the catheter of the
invention configured for antegrade deployment, showing a divider
that is significantly shorter than the divider described in
previous embodiments.
[0031] FIG. 17 shows a cut-away view of an embodiment of the flow
divider including a mesh or porous portion for perfusing from the
upper surface of the flow divider.
[0032] FIG. 18 shows a cut-away view of an alternate internal
structure of the flow divider of FIG. 17.
[0033] FIG. 19 shows an embodiment of the flow divider of the
invention comprising a peripheral tube and membrane structure.
[0034] FIG. 20 shows a cross section of the flow divider of FIG. 19
taken along line 20-20.
[0035] FIG. 21 shows an embodiment of the flow divider of the
invention with welds or joined areas between an upper and a lower
film of the flow divider to give additional structure and rigidity
to the flow divider.
[0036] FIG. 22 shows a cross section of the flow divider of FIG. 20
taken along line 22-22.
[0037] FIG. 23 shows an alternate embodiment of FIG. 21 with larger
joined areas between the upper and lower films of the flow
divider.
[0038] FIG. 24 shows an embodiment of the flow divider having a
membrane or film portion and a peripheral tube portion, that is
deployed using a pair of wires.
[0039] FIG. 25 shows a cross section of the flow divider of FIG. 24
taken along line 25-25.
[0040] FIG. 26 shows a cross section of an embodiment of the flow
divider that is sack-like, rather than having a peripheral channel,
and that uses a pair of deployment wires to deploy.
[0041] FIG. 27 shows an alternate embodiment of the flow divider of
FIG. 24 that is deployed using only a single wire.
[0042] FIG. 28 shows a perspective view of an embodiment of the
catheter of the invention wherein the flow divider comprises a
shroud deployed by means of movable ribs.
[0043] FIG. 29 shows a top view of the catheter of FIG. 28 in a
collapsed configuration.
[0044] FIG. 30 shows a top view of the catheter of FIG. 28 in a
deployed configuration.
[0045] FIG. 31 shows a first embodiment of the flow divider of the
invention deployed from a lumen within a catheter.
[0046] FIG. 32 shows a cross section of the flow divider and aorta
of FIG. 31 taken transversely through the aorta.
[0047] FIG. 33 shows a flow divider, having a flexible stiffening
spine, deployed from within a lumen having an opening in the distal
end of the catheter and coupled to a deployment wire at a point
intermediate the ends of the spine.
[0048] FIG. 34 shows the flow divider and catheter of FIG. 33 with
the deployment wire retracted to the distal end of the catheter so
that the catheter is positioned for perfusion of the arch
vessels.
[0049] FIG. 35 shows the flow divider of FIG. 33 partially
withdrawn into the catheter.
[0050] FIG. 36 shows an alternate embodiment of the flow divider of
FIG. 33 with an additional withdrawal wire.
[0051] FIG. 37 shows the flow divider of FIG. 36 partially
withdrawn into the catheter.
[0052] FIG. 38 shows a fully deployed flow divider similar in
construction to the flow divider of FIG. 28, but that is deployed
from within a lumen in a catheter shaft.
[0053] FIG. 39 shows the flow divider of FIG. 38 in an undeployed
state within the catheter.
[0054] FIG. 40 shows the flow divider of FIG. 38 partially
deployed.
[0055] FIG. 41 shows an embodiment of the flow divider comprising a
flexible tongue that is folded back within the catheter shaft, and
deployed using a deployment wire to push the flow divider out.
[0056] FIG. 42 shows the flow divider of FIG. 41 fully deployed,
and with the deployment wire retracted.
DETAILED DESCRIPTION OF THE INVENTION
[0057] The catheter described herein with all of its preferred
features represents a versatile device having multiple uses. The
invention provides a catheter having a flow divider, indicated
generally by the reference number 110 in the accompanying drawings,
positioned near the distal end of the catheter for dividing the
blood flow through a lumen, preferably at a point where at least
one second lumen branches from the first lumen, and for perfusing
the branch lumen or lumens. However, the invention will be
described more specifically herein relating to an aortic catheter
having a flow divider 110 configured to be positioned in the aortic
arch and having a length sufficient to divide the blood flow in the
aortic lumen so that the arch vessels are at least partially
isolated. The flow divider 110 may be formed in a variety of
configurations. In general the flow divider 110 will have an
undeployed state wherein the flow divider 110 is contained in a
relatively small volume around the circumference of the distal end
of the catheter, nearest the heart. The catheter will generally
have a deployed state in which the length and width of the flow
divider 110 is sufficient to divide blood flow in the aorta in the
vicinity of the ostia of the arch vessels, and an undeployed state
in which the flow divider 110 is collapsed around the shaft of the
catheter and preferably has an exterior circumference that is not
significantly larger than the exterior circumference of the
catheter.
[0058] The flow divider 110 may comprise one or more inflatable
chambers or one or more selectively deployable shrouds. The
balloons may be relatively non-compliant or they may be compliant,
exhibiting elastic behavior after initial inflation, for example,
to closely fit the aortic lumen size and curvature.
[0059] The catheter may further include one or more additional or
auxiliary flow control members located on the catheter either
distal or proximal from the flow divider 110 to further segment the
patient's circulatory system for selective perfusion to different
organ systems within the body or to assist in anchoring the
catheter in a desired position. These auxiliary flow control
members may comprise inflatable balloons or selectively deployable
external catheter valves, The anchoring members may be inflatable
balloons or other anchoring structures that provide sufficient
force or friction to prevent the catheter from drifting from a
selected position within the aorta.
[0060] Usable auxiliary flow control members include, but are not
limited to, expandable or inflatable members such as inflatable
balloons and valves including collapsible/expandable valves of
various configurations including retrograde valves, antegrade
valves, and various central flow and peripheral flow valves. A
combination of valves and inflatable members may be used as
appropriate for a given procedure, thus in some embodiments, the
catheter body can include one or more antegrade and retrograde
valves, as well as one or more inflatable balloons. Inflatable
balloons and collapsible/deployable valves have been previously
described, and are known in the industry, and any desirable or
practical inflatable balloon or deployable valve may be used.
Inflatable balloons typically include an interior chamber that is
in fluid communication with an inflation lumen extending within the
catheter shaft from a location from within the respective flow
control member to a location in the proximal portion which is
adapted to extend out of the patient.
[0061] Preferably, the flow divider 110, and any auxiliary flow
control members, or anchoring members, if present, are mounted
directly on an elongated catheter shaft. In a preferred embodiment,
the catheter shaft includes at least three lumens, one lumen for
inflating or otherwise deploying the flow divider 110, a second for
perfusion of the arch vessels, and a third guidewire lumen. In
alternate embodiments, additional lumens may be included for
deploying the auxiliary flow control members, for measuring the
pressure at desired locations within the aorta, or for perfusing
other isolated segments of the patient's circulatory system. The
catheter may be configured for retrograde deployment via a
peripheral artery, such as the femoral artery, or it may be
configured for antegrade deployment via an aortotomy incision or
direct puncture in the ascending aorta. The catheter is
characterized by a flexible catheter shaft placed by surgical
cutdown or needle/introducer guidewire technique into the vessels
of the lower or upper extremity or neck. Other large internal
vessels may also be used.
[0062] Anticoagulants, such as heparin and heparinoids, may be
applied to the surfaces of the catheter and/or flow control members
as desired. Anticoagulants may be painted or sprayed onto the
device. Anticoagulants other than heparinoids may also be used, for
example monoclonal antibodies such as REOPRO (Eli Lilly and Co.,
Indianapolis, Ind.). A chemical dip comprising the anticoagulant
may also be used. Other methods known in the art for applying
chemicals to catheters may be used.
[0063] Attention is now drawn to the figures, which illustrate
examples of several embodiments of the invention, and wherein like
numbers refer to similar elements or features. FIG. 1 illustrates a
first embodiment of the aortic catheter 100 of the invention. The
aortic catheter 100 has an elongated catheter shaft 102 having a
proximal end 104, that preferably extends out of the patient's
body, and a distal end 106 closest to the patient's heart. The
elongated catheter shaft 102 preferably has an overall length
sufficient to reach from the arterial access point where it is
inserted into the patient to its deployed position within the
aorta. For femoral artery deployment in adult human patients, the
elongated catheter shaft 102 preferably has an overall length from
approximately 60 cm to 120 cm, and more preferably 70 cm to 90
cm.
[0064] In a preferred embodiment, the elongated catheter shaft 102
has an outer diameter that is preferably approximately 9 to 22
French (3.0 to 7.3 mm), and more preferably 12 to 18 French (4.0 to
6.0 mm) for use in adult human patients. Catheters for pediatric
use, or use in non-human subjects, may require different dimensions
and would be scaled accordingly. The elongated catheter shaft 102
is preferably formed of a flexible thermoplastic material, a
thermoplastic elastomer, or a thermoset elastomer. Suitable
materials for use in the elongated catheter shaft 102 include, but
are not limited to, polyvinylchloride, polyurethane, polyethylene,
polyamides, polyesters, silicone, latex, and alloys or copolymers
thereof, as well as braided, coiled or counterwound wire or
filament reinforced composites. Additionally or alternatively, the
elongated catheter shaft 102 may be constructed using metallic
tubing or a solid wire, for example stainless steel hypodermic
tubing or wire or superelastic nickel-titanium alloy tubing or
wire. Preferably, the aortic catheter 100 includes one or more
location markers 116, such as radiopaque markers and/or
sonoreflective markers, to enhance imaging of the aortic catheter
100 during deployment using standard fluoroscopy, ultrasound, MRI,
MRA, transesophageal echocardiography, or other techniques. For
example, in the illustrative embodiment shown in FIG. 1, a
radiopaque location marker 116 is positioned near the distal end
106 of the catheter shaft 102, and another near the proximal end of
the flow divider 110, to assist in positioning the flow divider 110
within the aortic arch. The radiopaque location markers 116 may be
formed as a ring or disk of dense radiopaque metal such as gold,
platinum, tantalum, tungsten, or compounds or alloys thereof, or a
ring of a polymer or adhesive material heavily loaded with a
radiopaque filler material.
[0065] The flow divider 110, of FIG. 1, is mounted proximate the
distal end 106 of the elongated catheter shaft 102. In the
embodiment shown in FIGS. 1 through 4, the flow divider 110 is
shown in the form of a flat elongate expandable inflatable balloon
bonded to the catheter shaft 102 by heat welding or with an
adhesive. The inflatable flow divider 110 has a deflated state in
which the flow divider 110 adheres closely to the catheter shaft
102 so that the collapsed diameter of the flow divider 110 is,
preferably, not substantially larger than the diameter of the
catheter shaft 102, and an inflated state in which the flow divider
110 expands to dimensions sufficient to divide blood flow in the
aortic arch of the patient into two fluid flow channels.
Preferably, the flow divider 110 will be formed so that, when
inflated, the flow divider 110 automatically assumes and maintains
a desired shape, without any additional stiffening structure.
However, in some embodiments, it may be desirable to include means
for assisting the flow divider 110 in maintaining a desired shape,
and any known means for accomplishing this may be used. For
example, the divider may include ribs or other stiffening
structures coupled to the flow divider 110, or formed as an
integral part of the flow divider 110. Alternatively, the flow
divider 110 may include mattress type welds, or internal welds or
columns. The outer surface of flow divider 110 may include a
friction increasing means such as a friction increasing coating or
texture to increase friction between the flow divider 110 and the
aortic wall, when deployed, to assist in maintaining the flow
divider 110 in a desired position within the aorta.
[0066] FIG. 2 is a side view of the catheter 100, showing that the
flow divider 110 is preferably coupled only to a portion of the
diameter of the catheter shaft 102. Thus, perfusion ports 118 are
unobstructed.
[0067] FIG. 3 is a cross section of the catheter shaft 102 taken
along line 3-3. The elongated catheter shaft 102 preferably has at
least three lumens, an inflation lumen 108 that is used to deploy
the flow divider 110, a perfusion lumen 112 that is used to perfuse
one of the fluid flow channels, and a guidewire lumen 114. The
configuration of the lumens is shown for illustrative purposes
only, and any reasonable configuration of lumens within the
catheter may be used.
[0068] The flow divider 110 is shown in a deployed state in FIG. 4.
Preferably, the flow divider 110 in its deployed configuration
includes a distal portion 120 that extends beyond the distal end of
the catheter 100 in order to seal snugly against the aortic lumen
wall. The proximal portion 122 of the divider 110 is shown shaped
similarly to the distal portion 120, however, in this embodiment
the shape of the proximal portion 122 of the divider 110 is not
critical to the invention and could be triangular, square, or any
other desired shape. In other embodiments, it may be preferable
that the shape be chosen to encourage low turbulence, or possibly
laminar, fluid flow where the fluid flow from the flow channel
above the divider 110 and the fluid flow from below the flow
divider 110 meet at the trailing edge of the proximal portion
122.
[0069] Referring to FIG. 5, an aortic catheter 100 of the invention
is shown in a cutaway perspective view deployed within a patient's
aorta B via femoral artery access. In order to facilitate placement
of the catheter 100 within the aorta B, and to improve the
stability of the catheter 100 in the proper position in the
patient's aorta B, a distal region 124 of the aortic catheter 100
may be preshaped to conform to the internal curvature of the
patient's aortic arch. The distal region 124 represents a J-shaped
curve of approximately 180 degrees of arc with a radius of
curvature of approximately 4 to 10 centimeters, for use in a
typical adult human patient. The distal end 106 of the aortic
catheter 100 may be skewed slightly out of the plane to accommodate
the forward angulation of the typical patient's aortic arch and
ascending aorta.
[0070] In use, the flow divider 110 is positioned within the aortic
arch, as seen in a side view in FIG. 6, with the flow divider 110
positioned to redirect blood flow originating from the heart A
through a selected region of the aortic lumen B below the divider
110. The edge of the distal end 120 of the flow divider 110, as
well as the sides of the flow divider 110, contact the aortic wall.
Thus, the aortic lumen B is divided into two channels, one above
the aortic divider 110 and one below the aortic divider 110. Blood
flow originating from the heart A is prevented from entering the
region of the aortic lumen providing blood flow to the arch vessels
by the flow divider 110, which directs the blood to the flow
channel below the flow divider 110. Blood flow below the flow
divider 110 bypasses the arch vessels carrying any embolic material
C harmlessly past the cerebral circulatory system. The channel
above the flow divider 110 is perfused with a selected fluid, such
as oxygenated normothermic blood, oxygenated hypothermic blood,
blood substitutes such as PERFLUBRON or other perfluorocarbon
compounds, radiopaque dyes for angiography, or the like, introduced
through the perfusion lumen 112 of the catheter shaft 102. The
selected fluid exits the catheter shaft 102 through perfusion ports
118. Because the proximal end 122 of the flow divider 110 is not
sealed against a wall of the aortic lumen B, it is preferable that
the pressure and flow rate of fluid perfused through the catheter
100 be sufficient to prevent backflow from the proximal end 122 of
the divider 110 and also to hinder fluid flow around the edges of
the flow divider 110. Thus, preferably, only the perfused fluid
from the perfusion lumen 112 enters the arch vessels.
[0071] In the embodiment shown in FIGS. 1 through 7, it is
contemplated that some of the selected fluid perfused through the
perfusion ports 118 will flow to the arch vessels, and some will
flow along the upper surface of the flow divider 110 until the
perfused fluid leaves the trailing edge of the flow divider 110. It
may be preferable that the blood flow at this point be laminar with
little mixing between the fluid originating from the flow channels.
However, even if turbulence results near the trailing edge of the
flow divider 110, embolic material C in the blood originating from
the heart A will have already passed the arch vessels, thereby
achieving the objective of preventing embolic material from
entering the cerebral circulatory system.
[0072] It is not essential that the edges of the flow divider 110
create a perfect seal with the wall of the aorta. Some leakage of
blood around the flow divider 110 may be tolerated because the
fluid perfused through the perfusion lumen 112 creates a pressure
gradient from above the flow divider 110 to below the flow divider
110 so that any potential embolic material will not enter the flow
channel above the flow divider 110.
[0073] The ability to create a good seal between the aortic lumen
and the edges of the flow divider 110 may be enhanced by
pre-shaping the flow divider 110 to conform to the aortic lumen.
The flow divider 110 may be arcuate along the longitudinal axis of
the flow divider 110 as is seen in FIG. 7, which shows a cross
sectional view of the flow divider 110 taken along lines 7-7 in
FIG. 6. The curve of the flow divider 110 may help prevent the flow
divider 110 from collapsing against the aortic lumen wall when the
upper side of the divider 110 is under greater pressure than the
lower side of the flow divider 110. As shown in FIG. 8, in
alternate embodiments, the arch of the flow divider 110 could be
reversed.
[0074] In an alternate embodiment seen in FIG. 9, the distal end
106 of the catheter 100 passes through the flow divider 110 at a
point 126 to extend on the opposite side of the flow divider 110.
This configuration is useful for procedures wherein it is desired
to perfuse the flow channel below the divider 110 with a selected
fluid. The catheter 100 may use an additional separate corporeal
perfusion lumen, or alternatively, the guidewire lumen 114 may be
used. This embodiment is also usable for configurations including
an auxiliary flow control member on the catheter positioned between
the distal end 106 of the catheter 100 and the proximal end 122 of
the flow divider 110.
[0075] FIG. 10 discloses a catheter configuration wherein the
catheter 116 passes from the lower side of the flow divider 110 at
128 to the upper side of the flow divider 110, and then, from the
upper side of the flow divider 110 to the lower side of the flow
divider at 126. The flow divider 110 is preferably arcuate, but in
an orientation opposite that of the prior embodiments, as seen in
the cutaway view of FIG. 8. Although, in alternate embodiments, the
arch of the flow divider 110 could be reversed, as shown in FIG. 7.
The catheter of this embodiment is seen in use in an aortic arch in
FIG. 11. The advantage of this configuration is that both ends 120,
122 of the flow divider 110 seal against the aortic lumen wall,
instead of the proximal end 122 of the flow divider 110 being open
as in the previous embodiments. Furthermore, in this embodiment it
may be preferable to maintain a higher pressure on the lower side
of the flow divider 110 than on the upper side of the flow divider
110, for example by perfusing oxygenated blood through the
guidewire lumen 114 or an additional separate corporeal perfusion
lumen. If the pressure on the lower side of the flow divider 110 is
maintained at a higher pressure than the pressure on the upper side
of the flow divider 110, the flow divider 110 may be urged upward,
causing the edges of the flow divider 110 to contact the aortic
wall with greater force, assisting to seal the edges of the flow
divider 110 against leakage. FIG. 12 shows a flow divider 110
similar to the flow divider 110 of FIG. 10, but with the flow
divider 110 periphery concave upward, which may assist in sealing
the edges of the flow divider 110 against leakage. However, a
complete seal is not critical in these or any other embodiments of
the invention described herein, as pressure gradients and/or
balanced perfusion flow minimizes flow around the edges of the flow
divider 110.
[0076] Any embodiments of the catheter 100 of the invention
described above may further include auxiliary flow control members.
The auxiliary flow control members may be used to further
compartmentalize the patient's circulatory system, or may be used
for other functions such as assisting in securely anchoring the
catheter in a chosen position. An example of a catheter of the
invention further comprising an auxiliary flow control member is
seen in FIG. 13, which shows an auxiliary flow control member 130
coupled to the distal end of the catheter 100 proximate the distal
end 122 of the flow divider 110. The auxiliary flow control member
130 is positioned within the aorta and is fully deployed, occluding
the aorta. The auxiliary flow control member 130 shown in FIG. 13
is an inflatable balloon bonded to the catheter shaft 102 by heat
welding or with an adhesive. Alternatively, the auxiliary flow
control member 130 could be a deployable valve, or other structure.
Deployable valves suitable for use in this application are
described in commonly owned U.S. Pat. Nos. 5,827,237 and 5,833,671,
which are hereby incorporated in their entirety. Suitable materials
for the inflatable anchor member 130 include, but are not limited
to, elastomers, thermoplastic elastomers, polyvinylchloride,
polyurethane, polyethylene, polyamides, polyesters, silicone,
latex, and alloys or copolymers and reinforced composites thereof.
In alternate embodiments, the auxiliary flow control member 130 may
be positioned on the proximal side of the flow divider 110, if
desired. The auxiliary flow control member 130 may also be used to
anchor the catheter 100 so that it does not migrate out of its
optimal position during the medical procedure. The outer surface of
an auxiliary flow control member 130 used to anchor the catheter
100 may include a friction increasing means such as a friction
increasing coating or texture to increase friction between the
auxiliary flow control member 130 and the aortic wall, when
deployed. Alternatively, an auxiliary flow control member 130,
which may be an inflatable balloon or deployable valve, can be
mounted on a separate catheter and introduced through a lumen
within the catheter 100.
[0077] FIG. 14 shows the catheter of FIG. 13 deployed within an
aorta with the flow divider 110 fully deployed, and auxiliary flow
control member 130 partially collapsed. As blood flow resumes from
the heart A, embolic material C is diverted away from the arch
vessels by the flow divider 110.
[0078] The previous embodiments have been described using a
catheter configured for a retrograde approach to the aorta from a
peripheral vessel such as the femoral artery. The invention could
easily be modified for alternate deployment means. For example,
FIG. 15 shows a catheter 100 configured for central antegrade
deployment in the aortic arch through an aortotomy or direct
puncture in the ascending aorta. The catheter 100 and flow divider
110 is configured similarly to the catheters disclosed in previous
embodiments. Other embodiments of the invention may be configured
for peripheral insertion through the subclavian or axillary
arteries.
[0079] FIG. 16 shows an alternate embodiment having a very short
flow divider 110. In this embodiment, the flow divider 110 does not
extend beyond the ostia of the arch vessels, and relies on the
creation of two adjacent fluid flow streams or channels that
preferably exhibit laminar flow, or low turbulence flow between the
two flow streams. Even if some turbulence results near the trailing
edge of the flow divider 110, embolic material C in the blood
originating from the heart A will preferably have passed the arch
vessels before the fluid streams mix significantly.
[0080] Preferably, the arch vessels receive fluid only from the
flow stream originating from the perfusion ports 118 above the flow
divider 110.
[0081] FIG. 17 discloses an alternate embodiment of the flow
divider 110, wherein the top surface of the flow divider 110
comprises a mesh or porous region 132. The perfusion ports 118
allow a selected fluid to enter the interior chamber 134 of the
flow divider 110 before the fluid passes through the mesh or porous
region 132 to perfuse the aorta. The material or materials used in
the flow divider 110 are preferably characterized by properties
that allow an internal pressure within the flow divider 110 to be
maintained at a sufficient level to maintain the deployed
configuration of the flow divider 110 to divide the aorta, while
also allowing a controlled volume of fluid to escape from the flow
divider 110 through the mesh or porous region 132 on the upper
surface of the flow divider 110 for perfusing the arch vessels.
Thus, the surface of the flow divider 110 may have porous regions
that allow a fluid to be perfused at a known rate when a specific
pressure is attained. In the embodiment shown in FIG. 17, an
inflatable peripheral tube 136 surrounds the periphery of the flow
divider 110, however, in alternate embodiments, this feature may be
omitted. In embodiments including an inflatable peripheral tube
136, it is preferable that the peripheral tube 136 be inflated from
a separate additional lumen. However, FIG. 18 discloses an
embodiment of the flow divider 110 of FIG. 17 wherein a single
inflation and perfusion lumen may be used. In this embodiment,
perfused fluid passes from the catheter 100 into the peripheral
tube 136 to inflate the peripheral tube 136. Apertures 138 between
the inflatable peripheral tube 136 and the interior chamber 134 of
the flow divider 110 allow fluid to flow from the peripheral tube
136 into the chamber 134 within the inflatable flow divider 110.
The fluid then passes through the mesh or porous region 132 of the
flow divider 110 to perfuse the aorta. Preferably, the apertures
138 of the peripheral tube 136 are sized so that the pressure
within the peripheral tube 136 is higher than the pressure within
the chamber 134 of the flow divider 110.
[0082] The porous and non-porous sections of the flow divider 110
may be formed from the same or separate materials. Suitable
materials for the non-porous portions of the flow divider 110
include, but are not limited to, elastomers, thermoplastic
elastomers, polyvinylchloride, polyurethane, polyethylene,
polyamides, polyesters, silicone, latex, and alloys or copolymers,
and reinforced composites thereof. Suitable materials for the
porous portions of the flow divider 110 include meshes, woven and
nonwoven fabrics, and porous membranes, such as microperforated or
laser perforated polymer or elastomer films. For example, polyester
meshes may be used, such as meshes made by Saati Corporations and
Tetko, Inc. These are available in sheet form and can be easily cut
and formed into a desired shape. Other meshes and porous materials
known in the art, which have the desired characteristics, are also
suitable.
[0083] Referring to FIG. 19, an embodiment of the flow divider 110
is disclosed having a nonporous film 140 surrounded by a peripheral
tube 136 acting as a support structure. Inflation of the peripheral
tube 136 causes deployment of the film 140 within the aorta. holes
are positioned over the perfusion apertures 118 to allow perfusion
of the region above the flow divider 110. FIG. 20 is a cross
section view of the flow divider 110 of FIG. 19 taken along line
20-20. It is possible to make the flow divider 110 of FIG. 19 by
fabricating an oval balloon and affixing the central portion of the
top and bottom layers together, leaving a peripheral region where
the upper and lower layers are not coupled together forming the
inflatable peripheral tube 136. Alternatively, the peripheral tube
136 and film 140 of the flow divider 110 may be formed of separate
components and affixed together by a known means for joining such
materials, such as by heat welding or adhesives.
[0084] FIGS. 21-23 represent alternate embodiments of the flow
divider 110 with welds or joined areas 142 between an upper and a
lower film of the flow divider 110 to give additional structure and
rigidity to the flow divider 110. FIG. 21 discloses an embodiment
wherein the interior surface of the upper film has been coupled to
the interior surface of the lower film, preferably by spot heat
welding or adhesive. The resulting structure maintains the geometry
of the flow divider 110 and provides it with additional rigidity.
FIG. 22 is a cross section view of the flow divider 110 of FIG. 21
taken along line 22-22. FIG. 23 shows an alternate embodiment of
FIG. 21 with larger joined areas 142 between the upper and lower
films of the flow divider 110 creating well defined peripheral tube
136 and lateral or branch support members 144. In alternative
embodiments, the film 140 and peripheral tube 136 and lateral or
branch support members 144 may be fabricated as separate components
and joined using any known means for doing so, including the use of
adhesive or heat welding.
[0085] FIGS. 24-26 disclose embodiments of the flow divider 110
that are deployed by extending one or more preshaped deployment
wires 146, 148 from within the catheter 100. FIG. 24 shows an
embodiment that employs two wires for deployment. This embodiment
includes a nonporous film 140 surrounded by a peripheral tube 136
in which the deployment wires 146 and 148 reside. The deployment
wires 146, 148 are coupled at one end to the distal end the
catheter shaft at points 152. The deployment wires 146, 148 pass
through one lumen, or alternatively two parallel lumens, from the
proximal end 104 of the catheter 100 to the distal region of the
catheter, and through deployment wire apertures 150 to the external
surface of the distal region of the catheter 100. In the
non-deployed state, the flow divider 110 is preferably folded
tightly against the exterior of the catheter shaft 102 so that the
outer diameter of the folded flow divider 110 is not much larger
than the diameter of the catheter shaft 102. The flow divider 110
is deployed by pushing the proximal end of the deployment wires
146, 148 through lumens into the catheter shaft. As the deployment
wires 146, 148 are extended from within the catheter 100, the
deployment wires 146, 148 cause the flow divider 110 to deploy. The
deployment wires 146, 148 are preferably preshaped to assume the
desired configuration. FIG. 25 is a cross section view of the
divider of FIG. 24 taken along line 25-25, and shows the deployment
wires 146, 148 within the peripheral tube 136 of the deployed flow
divider 110. In an alternate embodiment, as seen in FIG. 26, the
flow divider 110 may be sack-like with the deployment wires 146,
148 preshaped to hold the flow divider 110 in an open or deployed
configuration.
[0086] FIG. 27 discloses an alternate embodiment requiring only a
single deployment wire 154. In this embodiment, the deployment wire
154 is not coupled to the distal end 106 of the catheter 100.
Instead, the end of the deployment wire 154 is threaded through the
peripheral tube 136 in a clockwise or counterclockwise direction.
The deployment wire 154 is preferably preshaped to assume the
desired configuration and includes a rounded end 156 for better
tracking and to prevent the deployment wire 154 from puncturing the
flow divider 110.
[0087] FIG. 28 discloses a perspective view of an embodiment of the
catheter of the invention wherein the flow divider 110 comprises a
shroud 164 deployed by means of movable ribs or arms 162. The flow
divider 110 seen in FIG. 28 comprises a plurality of mechanical
pivot arms 162 with a film or web-like shroud 164 bonded to the
catheter shaft 102 and the pivot arms 162. The pivot arms 162 may
be mechanically extended, but in alternate embodiments, fluid
pressure may be used to pivot the arms 162. In other alternate
embodiments, the pivot arms 162 may instead be hollow tubes, which
are extended by filling them with fluid under pressure. When the
pivot arms 162 are extended, the shroud 164 unfolds, and the flow
divider 110 is deployed. FIG. 29 shows the flow divider 110 of FIG.
28 in a collapsed or-undeployed state with the pivot arms 162
pivoted against the catheter shaft 102, and the shroud 164 folded
against the catheter shaft 102. FIG. 30 shows a top view of the
flow divider 110 in a deployed configuration. Once deployed, this
embodiment of the flow divider 110 is used in the same way as the
flow dividers previously described.
[0088] All of the previously described flow divider 110 embodiments
have been deployed from the external surface of the catheter shaft.
However, in other embodiments, the flow divider 110 may be deployed
from within one or more lumens in the catheter shaft. For example,
FIG. 31 discloses a flow divider 110 deployed within an aorta B,
and coupled to a deployment wire 170 that is extended from a lumen
with an opening in the distal end 106 of the catheter shaft 102.
The flow divider 110 is preferably comprised of a material or
materials with a shape memory, so that the flow divider 110 will
assume the desired configuration on release from the catheter shaft
102. Any known suitable materials may be used including, but are
not limited to, elastomers, thermoplastic elastomers,
polyvinylchloride, polyurethane, polyethylene, polyamides,
polyesters, silicone, latex, and alloys or copolymers, and
reinforced composites thereof. In some embodiments, the flow
divider 110 may include lateral or branch stiffeners to assist the
flow divider 110 in maintaining a desired configuration or shape.
Perfusion of the arch vessels in this embodiment, may be provided
by another perfusion source, such as a second catheter. FIG. 32 is
a cross section view of the flow divider 110 of FIG. 31 taken
transversely through the aorta B showing a preferred position of
the flow divider 110 within the aorta B.
[0089] FIG. 33 illustrates an alternate embodiment of the flow
divider 110 of FIG. 31. In this embodiment, the flow divider 110
includes a stiff spine 172 extending along the length of the flow
divider 110 with a deployment wire 170 coupled to the spine 172 at
a point intermediate the ends of the spine 172. The flow divider
110 may include additional stiffening structures if desired. The
flow divider 110 may be used independently or it may be deployed
through a catheter 100. The flow divider 110 is deployed by pushing
the flow divider 110 out of a lumen having an opening near the
distal end 106 of the catheter 100. The catheter 100 may then be
advanced until the distal end 106 of the catheter 100 is proximate
the point 174 at which the deployment wire 170 is coupled to the
spine 172 of the flow divider 110, as shown in FIG. 34. The
catheter 100 may include additional perfusion ports 118 near the
distal end 106 of the catheter 100 to perfuse the region above the
flow divider 110. FIG. 35 shows an embodiment of the flow divider
110 being withdrawn. In some embodiments withdrawal of the flow
divider 110 may be accomplished by pulling the flow divider 110
into the lumen of the catheter 100. The flow divider 110 may bend
at the connection point between the deployment wire 170 and the
flexible spine 172. FIG. 36 shows an alternate embodiment including
a tether wire 176 coupled to the proximal end 122 of the flow
divider 110 nearest the catheter 100. In this embodiment, the
catheter 100 need not be bent to be withdrawn. Instead, the flow
divider 110 is withdrawn by pulling the tether wire 176. This
aligns the end of the flow divider 110 with the opening of the
lumen into which the flow divider 110 will be withdrawn, as seen in
FIG. 37.
[0090] FIGS. 38-40 illustrate an embodiment of the flow divider 110
comprising a plurality of flexible arms 180 extending from a spine
or inner catheter 184 with a shroud or web 182 extending between
the flexible arms 180. The flow divider 110 is deployed from a
lumen within the catheter shaft 102 from an opening at the distal
end 106 of the catheter shaft 102. FIG. 38 shows the flow divider
110 deployed within the aortic lumen B. The flexible arms 180 are
arrayed extending outward from the shaft of the flow divider 110,
supporting the shroud or web 182 between the extended flexible arms
180. FIG. 39 shows the flow divider 110 of FIG. 38 disposed in an
undeployed state within the catheter shaft 102. FIG. 40 shows the
flow divider 110 partially deployed from within the catheter shaft
102. As the flow divider 110 is pushed from the distal end 106 of
the catheter 100, the flexible arms 180 spring outward, deploying
the shroud or web 182 between the flexible arms 180. The flow
divider 110 is withdrawn by pulling the flow divider 110 into the
catheter shaft 102. The flexible arms 180 fold again, but in the
opposite direction. In an alternate embodiment, the flow divider
110 may be coupled to the exterior surface of the catheter shaft
102, and have a sheath slid over the divider in its undeployed
configuration. The divider may then be deployed by sliding the
sheath along the catheter shaft 102 to expose the flow divider 110.
In another alternative embodiment, the flexible arms 180 may be
pivotally attached to the inner catheter 184, and the flow divider
110 may be mechanically deployed and retracted by deployment wires
(not shown) within the inner catheter 184. In yet another
alternative embodiment, the flexible arms 180 may be inflatable and
deflatable to deploy and retract the flow divider 110.
[0091] FIGS. 41 and 42 illustrate an embodiment of the flow divider
110 comprising a flexible tongue that is folded back within the
catheter shaft 102 and deployed using a deployment wire 186 to push
the flow divider 110 out. Referring to FIG. 41, the proximal end of
the flow divider 110 is coupled to the distal end 106 of the
catheter shaft 102 at point 188. Deployment is accomplished by
using a deployment wire 186 to push the flow divider 110 out of the
lumen in the catheter shaft 102. The dotted lines 110' show
intermediate positions of the flow divider 110 as it is deployed.
FIG. 42 shows the flow divider 110 of FIG. 41 fully deployed and
with the deployment wire 186 retracted. Once the deployment wire
186 is removed, the aorta above the upper surface of the flow
divider 110 can be perfuse through the same lumen used by the
deployment wire 186.
[0092] In one method of use, the aortic catheter 100 of any of the
embodiments described above may be introduced into the patient's
circulatory system through a peripheral artery access such as the
femoral artery, by the percutaneous Seldinger technique, through an
introducer sheath, or via an arterial cutdown. Referring more
specifically to FIG. 5, the catheter 100 is advanced up the
descending aorta and across the aortic arch, under fluoroscopic or
ultrasound guidance with the aid of a guidewire within the
guidewire lumen 114. The aortic catheter 100 is advanced until the
flow divider 110 is positioned in the aortic arch. This may be
determined by reference to the location markers 116. The divider
110 is then deployed, dividing the aortic lumen into two flow
channels. Using a multihead cardiopulmonary bypass pump or the
like, perfusion of oxygenated blood is started through the
perfusion ports 118 to perfuse the flow channel above the flow
divider 110, and thereafter to perfuse the arch vessels. Blood from
the heart is directed through the flow channel below the flow
divider 110. At the completion of the surgical procedure, and after
the majority of embolic material has passed harmlessly beyond the
arch vessels, the divider 110 is retracted or allowed to collapse.
The aortic lumen is then no longer divided into two flow channels,
and oxygenated blood is allowed to flow from the heart to the arch
vessels. The patient is then weaned off the bypass, and the
catheter 100 and other cannulas are withdrawn.
[0093] In an alternative method, a catheter embodiment configured
for antegrade deployment, such as those shown in FIGS. 15 and 16,
would be used similarly, except that access to the patient's
circulatory system would be made through a central access by an
aortotomy or incision directly into the ascending aorta. The aorta
may be accessed through a median sternotomy or other thoracotomy
using standard open-chest or minimally invasive surgical
techniques.
[0094] Either method may be used with the heart beating or with the
heart arrested, for example, by cardioplegic arrest. When used on
an arrested heart, the method may include the additional steps of
occluding the ascending aorta with a cross clamp or using an
auxiliary flow control member, as shown in FIG. 13, and infusing a
cardioplegic agent into the aortic root distal to the auxiliary
flow control member through a lumen in the catheter or through a
separate cannula, or into the coronary arteries via retrograde
infusion.
[0095] Modification of the operational characteristics or
procedures set forth above for use in vessels other than the aorta
for perfusion of blood to branch vessels, or for use of other
catheter configurations disclosed herein, are readily ascertainable
by those skilled in the art in view of the present disclosure.
* * * * *