U.S. patent application number 10/958184 was filed with the patent office on 2005-05-26 for implantable heart assist devices and methods.
This patent application is currently assigned to Paul A. Spence. Invention is credited to Ortiz, Mark, Spence, Paul A..
Application Number | 20050113632 10/958184 |
Document ID | / |
Family ID | 24720886 |
Filed Date | 2005-05-26 |
United States Patent
Application |
20050113632 |
Kind Code |
A1 |
Ortiz, Mark ; et
al. |
May 26, 2005 |
Implantable heart assist devices and methods
Abstract
Heart support and assist devices for supporting and assisting
the pumping action of the heart. Various embodiments include mesh
support devices, devices using straps, spiral-shaped devices,
catheter-based devices and related methods.
Inventors: |
Ortiz, Mark; (Milford,
OH) ; Spence, Paul A.; (Louisville, KY) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER
441 VINE STREET
CINCINNATI
OH
45202
US
|
Assignee: |
Paul A. Spence
5818 Orion Road
Louisville
KY
40222
|
Family ID: |
24720886 |
Appl. No.: |
10/958184 |
Filed: |
October 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10958184 |
Oct 4, 2004 |
|
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09677981 |
Oct 3, 2000 |
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6808483 |
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Current U.S.
Class: |
600/16 |
Current CPC
Class: |
A61B 17/00234 20130101;
A61M 60/40 20210101; A61B 2017/00243 20130101; A61M 60/894
20210101; A61M 60/122 20210101; A61M 60/268 20210101; A61M 60/857
20210101; A61F 2/2481 20130101; A61F 2/2487 20130101 |
Class at
Publication: |
600/016 |
International
Class: |
A61N 001/362 |
Claims
1. A system for supporting a heart having a left and right
ventricles separated by an interventricular septum, the system
comprising: at least one catheter, at least one flexible support
member configured to be carried within said catheter and having
first and second connecting ends, said flexible support member
capable of being introduced through said catheter into one of said
ventricles, around an external portion of the other of said
ventricles and secured using at least one of said connecting ends
such that a portion of the flexible support member supports the
interventricular septum within said one ventricle and another
portion of the flexible support member supports the external
portion of the other ventricle.
2. The system of claim 1, wherein said connecting ends are
configured to be connected to each other.
3. The system of claim 2, wherein at least one of said connecting
ends includes a locking element for engaging the other connecting
end and locking the first and second connecting ends together.
4. The system of claim 1, wherein one of said connecting ends is
configured to receive the other connecting end in an adjustable
manner to allow adjustable pressure to be applied around the other
ventricle.
5. The system of claim 1, wherein said connecting ends each
comprise loops.
6. The system of claim 1, further comprising two of said catheters,
each catheter including a gripping element for gripping a
respective connecting end.
7. A device for supporting a heart, said device comprising a rigid
annular band configured to have at least a portion bear against an
external surface of the heart, said portion including an inward
projection for supplying selective inward pressure against a
selected area of the external surface of the heart.
8. The device of claim 7, further comprising a plurality of said
inward projections disposed at spaced apart locations of said rigid
annular band.
9. The device of claim 7, wherein said rigid annular band is
configured to lie entirely outside the heart against the external
surface.
10. (canceled).
11. (canceled).
12. (canceled).
13. (canceled).
14. (canceled).
15. (canceled).
16. (canceled).
17. (canceled).
18. (canceled).
19. (canceled).
20. (canceled).
21. (canceled).
22. (canceled).
23. (canceled).
24. (canceled).
25. (canceled).
26. (canceled).
27. (canceled).
28. (canceled).
29. A method of supporting a heart having a plurality of walls, the
method comprising: introducing at least one catheter into the
heart, introducing a heart support member through the catheter and
into the heart, and securing the heart support member adjacent at
least one of the walls of the heart to restrict movement of the one
wall during a heartbeat.
30. The method of claim 29, wherein the heart includes left and
right ventricles separated by an interventricular septum, and said
catheter is introduced into the right ventricle.
31. The method of claim 30, further comprising: securing the heart
support member adjacent the interventricular septum within the
right ventricle.
32. The method of claim 30, further comprising: supporting an outer
surface of the left ventricle using the heart support member.
33. A method of supporting a heart having a plurality of walls, the
method comprising: securing a support member adjacent a weakened
area of at least one of the walls, and applying discreet pressure
to a selected area of the weakened area using an inwardly
projecting portion of the support member.
34. The method of claim 33, wherein the weakened area is an area
containing a papillary muscle of the heart.
35. The method of claim 33, wherein the support member further
comprises an annular band of rigid material, and the method further
comprises: securing a first portion of the band adjacent an
external wall of the heart, and securing a second portion of the
band adjacent an internal wall of the heart.
36. The method of claim 35, wherein the heart includes left and
right ventricles separated by an interventricular septum and
wherein: the first portion of the band is secured adjacent the
interventricular septum of the heart, and the second portion of the
band is secured adjacent an external wall of at least one of the
right and left ventricles.
37. A method of assisting the pumping action of the heart having
left and right ventricles separated by an interventricular septum,
the method comprising: inserting a support member within one of the
right and left ventricles and against the interventricular septum,
encircling the outside of the other of the right and left
ventricles with at least one external member, and coupling the
external member with the support member, and compressing said one
ventricle in a direction toward the interventricular septum.
38. The method of claim 37, wherein the compressing step is
performed by inflating a bladder between the external member and an
outside wall of the heart.
39. The method of claim 37, wherein the compressing step is
performed by pulling said external member with a tensile force.
Description
[0001] This application is a divisional of application Ser. No.
09/677,981 filed Oct. 3, 2000 (now pending), the disclosure of
which is fully incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to devices used to
physically support the heart and, alternatively, also actively
assist the pumping action of the heart.
BACKGROUND OF THE INVENTION
[0003] The treatment of heart failure over the long term is a
difficult problem. At the same time, weak cardiac muscle function
is becoming an increasing problem. Patients are surviving longer
and more patients are surviving myocardial infarcts leading to a
large pool of patients who are inadequately served by current
medical practice. Drug treatment to increase the strength of
mycardial contraction has been unsuccessful over the long term.
Recently, biventricular pacing (rather than the usual
univentricular pacing) has been tried and this offers some promise
in selected patients but is unlikely to solve the problem.
[0004] Devices will therefore remain the mainstay of treatment for
terminal heart failure. Conventional methods have been unable to
inject adequate energy into the cardiovascular system. Past
attempts with the Jarvic heart or other replacement systems have
met with problems such as failure due to thromboembolism. The
patient is typically connected to a bulky internal or external
controller and power supply for the heart replacement system. The
inside of the artificial heart exposes a large artificial surface
area to the flow of blood and clots develop as a result. These
clots eventually break off and lodge in the brain leading to
strokes or resulting in ischemic injury to other body organs. It
has also been postulated that long-term exposure of blood to large
artificial surfaces sets up a chronic inflammatory reaction which
may predispose the patient to infection.
[0005] Currently, there are two major areas of development. A
simplified system involves cannulation of the left ventricle or
atrium with a tube-like structure and pumping of blood from this
source into the aorta. A blood propeller system is located within
the tubing of this system. A drive system powers the pump. The
drive system can be located outside the patient, or can be
implanted within the patient. If implanted, energy may be
transmitted by induction coils from outside the body to the device.
This device requires considerable residual cardiac function to
operate. The heart must beat adequately to perform some function
and usually only the left ventricle is supported by the device.
Thus, right ventricular function must be adequate for survival.
[0006] The second and more complex pump is a totally implantable
heart. The patient's heart is entirely removed or both ventricles
are cannulated and artificial left and right ventricles are
attached by a surgeon. The patient has a large surface exposed to
the flow of blood as the blood comes in contact with the artificial
ventricles, the connection tubes and the valves. Blood clotting,
hemolysis and degradation of blood become problems in this
situation.
[0007] For an entire generation, attempts have been made to create
a heart assist device which leaves the native heart in place and
squeezes the native heart. The blood is thus exposed only to the
patient's natural tissue. Clotting on natural tissue is extremely
rare. Pneumatically and electrically driven devices have been
evaluated, but these devices have not reached clinical application.
These devices have wrapped around the entire heart and squeezed
both the left and right ventricles. Unfortunately, this does not
mimic the way the heart contracts.
[0008] U.S. Pat. No. 4,925,443 illustrates a heart assist device
including a tension band which is surgically placed within an
interventricular muscle wall in order to compensate for weakness of
the interventricular muscle wall or septum. An operating mechanism
then opens and closes a pair of pressure plates to compress the
left ventricle. The drawback to this device, however, is that the
interventricular wall or septum experiences significant trauma due
to the surgical implantation of the band within the wall or septum
itself. Especially in cases in which the interventricular wall is
already weakened, such trauma could severely damage the heart.
[0009] Another proposed device is disclosed in U.S. Pat. No.
5,119,804. With this device, the heart is placed within a cup
having a vacuum source connected to hold the cup in position around
the heart and having a pulsed pressure system to alternately apply
relatively high positive and negative pressures to provide systolic
and diastolic effects on the heart. This system, however, squeezes
the entire heart muscle at one time and will tend to cause weaker
portions of the heart to bulge outward while stronger portions of
the heart muscle retain a normal shape. Therefore, the contraction
applied to the heart muscle is not a natural one, but one that is
dictated by the particular heart problems of the patient.
[0010] Another ventricular assist device is disclosed in U.S. Pat.
No. 4,685,446. This device utilizes an inflatable balloon secured
to the end of a catheter and inserted into the left ventricle. The
balloon is inflated during left ventricular systole and then
deflated in a repeating manner. Unfortunately, this device will
also tend to cause weakened portions of the heart muscle to bulge
around the left ventricle rather than causing the intended function
of expelling blood from the ventricle. Thus, the ejection fraction
of blood can be deficient with this device as well.
[0011] Despite the intuitively attractive nature of heart assist
devices, no device has ever been clinically proven. Attention to
some physiologic details will make the difference. The left
ventricle is a thick-walled structure which propels blood into the
systemic circulation at high pressure. The left ventricle is shaped
as a truncated cone. During systole (contraction) this cone
shortens along its length and narrows around its circumference. By
this narrowing and shortening action, the internal volume of the
left ventricular cavity decreases and blood is expelled. In a
healthy heart, 60% to 70% of the blood volume (that is, the
ejection fraction) is expelled on each beat. As the heart fails,
the cavity enlarges, the heart wall thins and progressively smaller
fractions of blood are expelled on each beat. In other words, the
heart shortens and narrows much less during each beat.
[0012] The right ventricle has been described as a bellows pump. It
wraps around and attaches to the circumference of the outside of
the left ventricular wall. The outside wall of the right ventricle
is considerably thinner than the wall of the left ventricle and
also contracts against a lower pressure. The energy consumption of
the right ventricle is therefore much lower than that of the left
ventricle. The right ventricle expels blood when the muscle
shortens and reduces the diameter of the crescent shaped cavity
which is located between the outside wall the interventricular wall
or septum shared with the left ventricle.
[0013] It is not surprising that merely squeezing the left and
right ventricles with a device wrapped around both ventricles has
not been successful. With previous devices, the left ventricle does
not shorten from base to apex. There is also limited short axis
shortening because the device does not squeeze the left ventricle
in isolation, but with the right ventricle. To be effective the
left ventricle requires more controlled compression. Generally,
blood must be expelled from the ventricle in a more controlled and
complete manner.
SUMMARY OF THE INVENTION
[0014] The present invention is generally directed toward heart
support and assist devices including fully passive restraints,
combinations of passive and active devices and fully active devices
for assisting with heart contractions. Passive restraints generally
include an external support member, which may be a strap, web or
mesh, sheathing or other member configured to extend around the
outside of the heart coupled with an internal support member
extending within at least one of the ventricles and against one
side of the interventricular septum. This type of passive
restraining system can assist the heart muscle by supporting those
portions of the muscle necessary to produce efficient contractions
either naturally or with another active assist device. This support
is provided in a manner that minimizes trauma to the heart muscle.
Additional internal tensile members, such as cables, may be
connected to the external tensile member or members longitudinally
and/or transversely through one or both ventricles. These cables
will assist with long axis and short axis shortening of the heart
muscle during each contraction.
[0015] Combinations of passive and active devices may include, for
example, external support members, in the form of straps, sheaths,
wraps, mesh elements or webs, etc., combined with a blood pump
connected for fluid communication directly with the left ventricle,
right ventricle or both. Alternatively, a fluid inflatable bladder
may be placed between the external tensile member and the outside
surface of the heart to provide compression to one or both of the
ventricles to assist in pumping blood through the heart. Finally,
an active contraction device may integrate an external tensile
member system with a powered actuator device to provide cyclical
compression of the heart muscle through a pulling action on the
tensile member or members.
[0016] In another aspect, the invention is directed to a heart
assist device generally including a plurality of flexible tensile
members adapted to be wrapped circumferentially about the heart of
a patient. At least one tensile member is configured to extend
around the left ventricle and a second tensile member is configured
to extend around the right ventricle. A support member is
configured to be received within the right ventricle against the
interventricular septum and coupled to at least one of the first
and second tensile members. This support member may be a portion of
at least one of the tensile members or may be a separate member
connected to at least one of the tensile members. At least one
powered actuator may be operatively connected with the first and
second tensile members and operates to pull the tensile members
respectively against the left and right ventricles to expel blood
therefrom.
[0017] More preferably, the heart assist device includes a
plurality of tensile members configured to extend around the left
ventricle and a plurality of tensile members configured to extend
around the right ventricle. Each tensile member is secured at least
indirectly to the support member. The support member is preferably
a plate covered with a biocompatible material for inhibiting blood
clotting. The actuator pulls the tensile members extending around
the left ventricle against the outside surfaces of the heart and
pulls the support member or plate against the interventricular
septum in an opposing direction. The tensile members extending
around the right ventricle are pulled against the left ventricle in
an independent fashion.
[0018] One preferred embodiment of the invention may include a
plurality of pulley members coupled with the tensile members and
operating to allow a single powered actuator, such as an electric
or pneumatic actuator, to pull multiple tensile members.
Alternatively, multiple powered actuators may be used to
independently pull the various tensile members. The tensile
members, pulleys and other actuating structure may be contained in
a suitable jacket or sheath positioned around the heart.
[0019] In accordance with another aspect of the invention, at least
one internal tensile member is provided and configured to be
connected lengthwise within the left ventricle between the mitral
valve of the heart and the apex of the left ventricle. The internal
tensile member inhibits lengthening of the ventricle when the
powered actuator or actuators pull the tensile members to compress
the left and right ventricles. As further options, transverse,
internal tensile members may be connected within the left ventricle
between the outside wall thereof and the interventricular septum to
control widthwise expansion. Also, one or more internal tensile
members may be utilized in the right ventricle for similar
purposes.
[0020] As additional aspects of the invention, the tensile members
may be contained in sleeves to prevent cutting of the heart by the
tensile members during use. Also, a plurality of coronary
obstruction preventing members may be used between the tensile
members and the coronary arteries on the outside of the heart for
preventing the coronary arteries from being compressed and
obstructed by the tensile members.
[0021] The present invention also generally contemplates methods
for assisting the pumping action of the heart. In a preferred
embodiment, the method includes inserting an anchor member within
the right ventricle and against the interventricular septum;
encircling the outside of the right and left ventricles with
respective tensile members; coupling the tensile members with the
anchor member; and compressing the right and left ventricles by
pulling the tensile members against the outside of the heart. Other
methods will be apparent to those of ordinary skill based on a full
review of this disclosure.
[0022] In various aspects of the invention, a basic device for
assisting a heart may comprise a plurality of flexible, external
tensile members adapted to be wrapped circumferentially around the
heart of a patient. Preferably, this includes at least a first
external tensile member configured to extend around the left
ventricle and a second external tensile member configured to extend
around the right ventricle. In accordance with the invention, an
internal support member is configured to be received within at
least one of the left and right ventricles and against the
interventricular septum. This support member is coupled either
directly or indirectly to at least one of the first and second
external tensile members. The internal support member may comprise
a portion of one or more of the external tensile members or may be
a separate member, such as a plate, coupled with the external
tensile members. The external tensile members are preferably flat
straps or other similar structures that will not harm the outside
of the patient's heart, and may be formed from any biocompatible
material. In various embodiments, the support members may be
implanted either partially or completely through one or more
catheters.
[0023] In another embodiment of the invention, at least one of the
first and second external tensile members may be configured
generally in a spiral shape to facilitate the application of
compression to the heart. In this embodiment, for example, one or
more coils of the spiral may extend into one of the ventricles of
the heart and bear against one side of the interventricular septum
to form a support member as described above. An actuator is used to
draw the spiral-shaped external tensile member into a tighter,
coiled shape to actively compress or passively support one or both
ventricles of the heart.
[0024] In another embodiment of the invention, the first and second
external tensile members are configured as first and second halves
of a cup. The cup is configured to envelop the patient's heart and
comprises first and second shells with at least a first bladder
configured for disposition between one of the shells and an outside
surface of the heart. As with the other embodiments, one or more
support members extend between opposite sides of the cup and within
one or both ventricles of the heart to bear against the
interventricular septum. A pump is provided for selectively
inflating and deflating the bladder to apply compression to at
least one of the left and right ventricles. In the preferred
embodiment, a bladder is connected within each of the shells
associated with the cup for compressing both of the ventricles. The
support member or members are connected at a position generally
between the first and second halves of the cup such as by being
retained in place by the same connectors used to affix each half of
the cup together. The cup may be formed in one, two or more pieces
and, again, is formed from any suitable biocompatible material or
materials as with all of the implantable components of each
embodiment.
[0025] Various objectives, features and advantages of the invention
will become more readily apparent to those of ordinary skill in the
art upon review of the following detailed description taken in
conjunction with the the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective view showing one embodiment of the
invention in an illustrative manner coupled to a patient's
heart;
[0027] FIG. 2 is a partially fragmented perspective view showing
the heart assist device of FIG. 1 coupled to the patient's
heart;
[0028] FIG. 3 is a cross sectional view taken generally along line
3-3 of FIG. 2;
[0029] FIG. 3A is a cross sectional view similar to FIG. 3, but
illustrating optional inflatable bladders for providing a pump
assist to the heart;
[0030] FIG. 4 is perspective view illustrating an embodiment with a
single powered actuator for operating the heart assist device
through the use of pulleys;
[0031] FIG. 5 is a perspective view similar to FIG. 4, but showing
independent powered actuators;
[0032] FIG. 6 is a perspective view of another alternative assist
device comprising a spiral-shaped external tensile member;
[0033] FIG. 7 is an exploded perspective view illustrating another
alternative heart assist device comprised of a split cup and
inflatable bladder system;
[0034] FIG. 8 is a perspective view of another alternative heart
assist device used to directly pump blood into one or more heart
chambers;
[0035] FIG. 9 is a fragmented perspective view of the heart with
another embodiment of a passive heart support device implanted
around the left ventricle;
[0036] FIG. 10 is a perspective view of a passive heart support
device similar to FIG. 9 but having alternative internal support
members;
[0037] FIG. 11 is a transverse, cross sectional view of a heart
with another alternative passive support device;
[0038] FIG. 12 is a cross sectional view showing an initial step of
implanting a catheter-implanted heart support device;
[0039] FIG. 12A is a fragmented perspective view showing one
embodiment of a catheter-implanted heart support device;
[0040] FIG. 13A is a schematic, cross sectional view of the heart
during a later step of implanting the catheter-implanted support
device;
[0041] FIG. 13B is a cross sectional view similar to FIG. 13A, but
illustrating the fully implanted, catheter-implanted passive
support device;
[0042] FIG. 14A is a transverse, cross sectional view of a heart
schematically illustrating another catheter-based implantation
method of a passive support device;
[0043] FIG. 14B is a cross sectional view similar to FIG. 14A, but
illustrating a later point in the implantation procedure;
[0044] FIG. 14C is a cross sectional view similar to FIGS. 14A and
14B, but illustrating the fully implanted support device;
[0045] FIG. 15 is a partially sectioned, perspective view of a
heart with another alternative passive support device affixed
around the left ventricle;
[0046] FIG. 16 is a schematic, perspective view showing the heart
in cross section and another alternative passive support device;
and
[0047] FIG. 17 is a schematic, cross sectional view of the heart
shown in FIG. 16 with the device fully implanted around the left
ventricle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] FIG. 1 illustrates a heart assist device 10 constructed in
accordance with the invention and schematically illustrated
implanted within a patient 12 in surrounding relation to the
patient's heart 14. A power supply 16, such as an electric or
pneumatic power supply, is operatively connected to heart assist
device 10 for reasons to be discussed below. As generally shown in
FIG. 2, heart 14 has four chambers. The right atrium 18 receives
blood flowing through veins in the patient's body. The right
ventricle 20 pumps the blood to the lungs of the patient through
the pulmonary artery 22. The left atrium 24 receives oxygenated
blood flowing back from the patient's lungs through the pulmonary
vein and the left ventricle 28 pumps this blood out through the
aorta 30 to the patient's body. The right and left ventricles 20,
28 compress simultaneously during this pumping action and, in a
normal heart, anywhere between about 50% and 80% of the blood in
these chambers will be expelled as described above. In a heart
weakened, for example, due to heart attack or other conditions, the
efficiency of the heart will be reduced and, therefore, heart
assist device 10 will be used to increase the pumping action or
expulsion of blood from the right and left ventricles 20, 28. An
interventricular septum 32 separates the right and left ventricles
20, 28.
[0049] As further shown in FIGS. 2 and 3, device 10 preferably
comprises a plurality of flexible tensile members 40a through 40f.
In this embodiment, a flexible tensile member 40a is adapted to be
wrapped circumferentially around left ventricle 28, as is another
flexible tensile member 40b. A tensile member 40c may interconnect
tensile members 40a and 40b as shown. A similar system is shown
with tensile members 40d, 40e and 40f extending along the outside
of right ventricle 20. Each of these tensile members is effectively
connected to the other to form an integrated unit by connection to
an internal support anchor member 42. In this embodiment, support
member 42 comprises a plate surgically inserted into right
ventricle 20 and bearing against interventricular septum 32. Plate
42 may comprise a plate of rigid or semi-rigid polymeric material
or metallic material covered in a biocompatible material adapted to
resist blood clotting. Once plate 42 is implanted through a
suitable incision into right ventricle 20, flexible tensile members
40a, 40b, 40d and 40e may be sutured thereto as shown in FIG. 2.
Alternatively, one of the pairs of tensile members may be secured
to plate 42, while the other pair is secured to the first pair.
[0050] As shown in FIG. 2, tensile members 40a through 40f may,
comprise flexible cables contained within a sheath or sleeve of
biocompatible material. Internal flexible tensile members 44, 46,
48, 50 may be used to control the movements of the heart muscle as
device 10 is used to assist with the pumping action as described
further below. Two tensile members 44, 46 may be secured between
the annulus 52 of mitral valve 54 and the apex 56 of left ventricle
28. A button 58 may be used at the apex for securement purposes and
may bear against the intersections of tensile members 40c, 40f.
Transverse internal tensile members 48, 50 may extend crosswise as
best shown in FIG. 3 between the outer wall of left ventricle 28
and the interventricular septum 32. Tensile members 48, 50 may be
secured to any of the outer tensile members, as well as to plate 42
at opposite ends, or may be secured to the walls of the heart
itself. Similar internal tensile members may be used in the right
ventricle, although this is not preferred for the reason that it
may not be necessary as the motion of the right ventricle is
primarily in a direction toward the interventricular septum. Also,
it will be understood that tensile members 44, 46 may be secured in
other ways within left ventricle 28, such as by being secured to an
annuloplasty ring or to a replacement mitral valve.
[0051] FIG. 3A illustrates an alternative passive/active heart
assist device 10' taking the form of a modified version of device
10 shown in FIGS. 2 and 3. Device 10' includes various elements
having like reference numerals in FIG. 3, but adds an inflatable
bladder 47 which may be positioned between flexible tensile member
40a and the outside wall of left ventricle 28. Bladder 47 is
connected through a suitable conduit 49 to a fluid pump which may
direct air or other fluid into bladder 47 in a cyclical manner.
Inflation and subsequent deflation of bladder 47 will contract left
ventricle 28 against the support provided by internal support
member 42 to expel blood and subsequent deflation will allow left
ventricle 28 to expand and refill with blood. Alternatively, an
internal bladder 53 may be provided and cyclically inflated and
deflated, as shown, to expel blood from left ventricle 28 and allow
subsequent refilling of the ventricle with blood. Bladder 53 would
likewise be supplied with air or other appropriate fluid through a
catheter from a suitable pump device (not shown).
[0052] As further shown in FIG. 4, a series of pulley members 60
may be used with a single actuator 62, such as an electric solenoid
or pneumatic actuator having a reciprocating element 62a attached
to a series of cables or tensile members 63 extending through
pulley members 60. Actuator 62 may be contained in a suitable pouch
64 or other containment structure and springs 66, 68 may be used to
control the amount of compression applied by cables or tensile
members 63. As reciprocating member 62 moves inwardly in the
direction of the arrow in FIG. 4, cables or tensile members 63 will
move under tension and cause simultaneous compression of the right
and left ventricles.
[0053] FIG. 5 illustrates an embodiment similar to FIG. 4, but
using multiple actuators 70, 72, 74 for independently applying
compression to heart 14. Actuator 70 applies transverse compression
to an upper portion of heart 14, while actuator 72 applies
transverse compression to a lower portion of heart 14. Actuator 74
applies compression in a lengthwise direction. As with the other
embodiments, suitable flexible tensile members, such as cables
extending over or within straps, are provided to apply the
compression upon operation of actuators 70, 72, 74.
[0054] FIG. 6 illustrates another alternative heart support and
assist device 80 formed by a generally spiral shaped tensile member
82 extending around heart 14. Tensile member 82 preferably
comprises an outer hollow member 84 and an inner movable cable 86
connected at one end to a suitable actuator 88 affixed to a jacket
90 and at an opposite end being rigidly affixed by a connector 92
to jacket 90. An upper end of jacket 90 may be suitably connected
to heart 14, as through stitching 94. As shown in FIG. 6, two coils
of the spiral tensile member 82 extend into right ventricle 20 and
bear against interventricular septum 32 before exiting heart 14 and
again extending around the outside of jacket 90. The remaining
upper and lower sets of coils extend around the outside of jacket
90. This configuration is intended to compress both the right and
left ventricles 20, 28 of heart 14, while focusing on left
ventricle 28, which is the ventricle with which most heart patients
experience problems. Actuator 88 may be a conventional linear
electric actuator that cyclically pulls on cable 86 in concert with
the patient's own natural heart rhythm or as activated by a
conventional pacing device which sets the patient's heart rhythm.
It will also be appreciated that this type of generally
spiral-shaped support device may be used in a passive manner
without an active pump assist function. The spiral shape can be
used for adjusting the tightness of tensile member 82 against the
heart for achieving the proper amount of support.
[0055] FIG. 7 illustrates another alternative heart assist device
100 comprised of a cup having two halves 102, 104 which together
receive a patient's heart 14. Each half 102, 104 is respectively
comprised of an outer shell and innerinflatable bladder combination
106, 108 and 110, 112.
[0056] One or more internal support members 114, 116 extend
generally between halves 102, 104 through heart 14. Support members
114, 116 are intended to extend through one or both of the left and
right ventricles (not shown) of heart 14 and bear against the
interventricular septum (not shown), as with the support members
used in other embodiments of the invention. This provides support
for the interventricular septum during compression of the heart
without a significant amount of trauma to the heart muscle. Support
members 114, 116 may, for example, be one or more rigid plates or
flexible straps, or other suitable support members.
[0057] Respective connectors 118, 120 may be provided to affix
halves 102, 104 together. In this illustrative example, connectors
118 extend through holes 114a, 116a in support members 114, 116 and
into connectors 120 of half 104 to connect device 100 firmly
against heart 14. Additional connectors or other means may be used
to ensure that device 100 remains in position around heart 14. Once
in position, bladders 108, 112 may be cyclically inflated and
deflated to compress the left and right ventricles of heart 14
while the opposite side of one or each of the ventricles is
supported by members 114, 116. A pump 124 may be connected to
bladders 108, 112 for selectively inflating and deflating bladders
108, 112 with an appropriate fluid, such as air or liquid. Again,
pump 124 may be activated in correspondence with the patient's
heart rhythm, such as through the use of a conventional electrical
pacing device.
[0058] FIG. 8 illustrates another alternative heart assist device
130 comprised of a flexible strap system 132 configured for
disposition around a patient's heart 14 and connected with a
suitable internal support member 134 for bearing against one side
of the interventricular septum within one of the heart's
ventricles, as previously discussed. In this embodiment, at least
one pump 136 is directly connected through a suitable conduit, such
as a catheter 138, to one of the ventricles of heart 14. For
example, pump 136 may be connected to the left ventricle of heart
14 for directly pumping blood into the left ventricle to assist
with the movement of blood through heart 14. Likewise, another pump
140 may be directly connected to the right ventricle of heart 14
through another conduit 142 for assisting with blood flow through
the right ventricle. Pumps 136 and 140 may obtain blood from any
suitable vessel within the patient's body.
[0059] FIG. 9 illustrates a passive heart support device 150 shown
implanted on a heart 14 and, specifically, around left ventricle
28. Support device 150 includes a flexible mesh or web material 152
serving as an external support member around left ventricle 28 and
a plurality of internal support members 154, 156, 158 extending
through right ventricle 20 and against interventricular septum 32.
Internal support members 154, 156, 158 may be attached to mesh or
web element 152 in numerous ways, such as by stitching or other
quicker connection means. At least one end of internal support
members 154, 156, 158 will be detached from mesh or web element 152
for extension through right ventricle 20 during implantation and
then adjusted for tightness on heart 14 and secured to mesh or web
element 152 preferably at an opposite side of the heart. If
necessary, an external sheath 160, which may be elastic in nature,
may receive heart 14 after attaching device 150, as a further
securement means. Sheath 160 may include an open end 162 and a
closed end 164.
[0060] FIG. 10 illustrates an alternative device 150', which is
similar to device 150, and includes a mesh or web element 152 for
supporting an external portion of the heart. A plurality of
internal support members 162a, 162b and 164a, 164b are connected to
opposite sides of mesh element 152. Device 150', for example, may
be introduced into a patient's chest through a relatively small
port hole and, using catheter-based devices, internal support
elements 162a, 162b and 164a, 164b may be secured across the
interventricular septum as generally shown in FIG. 9.
[0061] FIG. 11 illustrates another alternative passive support
device 170 comprising an external support portion 172, which may
again be another flexible mesh or web element 172 and internal
support member 174, 176. In this embodiment, support member 176
extends only partially along the interventricular septum 32 and
internal support member 174 extends through septum 32 and connects
with external support member 172 at one end and internal support
member 176 at an opposite end. Support members 174 and 176 may be
separate members which are connected together or may be a single
integral member, as shown. Additional support members 178, 180,
shown in phantom, may be optionally used in addition to or as an
alternative to internal support member 174.
[0062] FIGS. 12, 12A and 13A-B illustrate a partially
catheter-based implantation device and method. Specifically, a
catheter 190 having a sharpened portion 192 is introduced from a
vein 194, for example, originating in the groin of the patient.
Catheter 190 enters right atrium 18 and pierces through wall 18a
into right ventricle 20. A heart support device 200 may comprise a
cable which, for example, may include a sheath (not shown) and
which acts as both an external and internal support members for
heart 14. Catheter 190 may be used to introduce opposite ends of
support device 200 through opposite walls of right ventricle 20, as
shown in FIG. 13A. Piercing member 192 may, for example, extend to
fully pierce through the wall of the heart, or device 200 itself
may pierce through the wall of heart 14. Device 200 includes two
looped ends 202, 204 with at least one of these ends being
collapsible in the form of a tightening noose. In the embodiment
shown, this is end 204. A tool 210 may be introduced through a
small port hole in the patient's chest and includes a hook member
212. Tool 210 extends through loop 204 and hook 212 may be used to
grasp looped end 202 to pull it through looped end 204. Looped end
204 is then tightened as shown in FIG. 13B so that an internal
portion 200a of device 200 lies against septum 32 within right
ventricle 20 and another portion 200b of device 200 lies on the
external surface of heart 14 adjacent left ventricle 28.
[0063] FIGS. 14A and 14B illustrate another alternative embodiment
of the invention in the form of a completely catheter-based
fixation method using first and second flexible gripper members
220, 222 which may be introduced through the same catheter (not
shown) or separate catheters (not shown). Gripper members 220, 222
include jaws 220a, 222a which may be actuated to grip the ends of a
support member 230. Support member 230 includes respective ends
230a, 230b retained between jaws 220a and 222a. As with the
previous embodiment, gripper members 220, 222 may be introduced
into right ventricle 20, pierced through the heart wall 14a
adjacent septum 32 and directed around the outside of left
ventricle 28. Support member 230 includes ratchet-type connector
ends 230a, 230b which may be connected together as shown in FIG.
14B with end 230b being inserted into end 230a and retained by the
teeth on end 230b. Jaws 220a, 222a release ends 230a, 230b and then
are used to grip the opposite end 230a, 230b after engagement to
allow pulling of the ends 230a, 230b in opposite directions for
tightening and locking device 230 around left ventricle 28. It will
be appreciated that other forms of the device, as well as other
forms of the connecting and locking elements may be used as well.
Also, other portions of the heart may be supported and this type of
catheter-based insertion method and device may be used in
conjunction with other supporting and/or assisting devices.
[0064] FIG. 15 illustrates another alternative heart support device
240 comprised of three flexible support members 242, 244, 246
extending around the outside of left ventricle 28. Portions 242a,
244a and 246a extend through the wall of the heart into right
ventricle 20 and connect with a support plate 248 lying against
septum 32.
[0065] FIGS. 16 and 17 illustrate another alternative passive heart
support device 250 comprising a substantially rigid annular member
having two ends (not shown) affixed to one another by a connector
252. Two inwardly projecting portions 254, 256 exert pressure
selectively to small areas of the heart muscle. Specifically, for
example, portions 254, 256 may be positioned to exert selective
support to the papillary muscle regions of the heart, or to other
weakened areas of the heart depending on the particular needs of
the patient. Support member 250 is rigid enough to provide such
support in a manner that prevents undesirable, outward bulging of
the heart muscle. As apparent from FIG. 16, device 250 may also be
configured to extend only around the outside surface of the
heart.
[0066] While the present invention has been illustrated by a
description of preferred embodiments and while these embodiments
have been described in some detail, it is not the intention of the
Applicants to restrict or in any way limit the scope of the
appended claims to such detail. Additional advantages and
modifications will readily appear to those skilled in the art. The
various features and concepts of the invention may be used alone or
in numerous combinations within each embodiment or between the
embodiments depending on the needs and preferences of the user.
This has been a description of the present invention, along with
the preferred methods of practicing the present invention as
currently known. However, the invention itself should only be
defined by the appended claims, wherein we claim:
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