US5131905A | 1992-07-21 | |||
US4536893A | 1985-08-27 | |||
US5201880A | 1993-04-13 | |||
EP0119357A1 | 1984-09-26 |
1. | A device for use with a natural heart for placement within the interior volume of a natural heart adjacent cardiac tissue thereof, said device comprising: a stint having a first ring for placement adjacent at least one of the atrioventricular annuli to stabilize and facilitate operation ofthe atrioventricular valve, and a second ring for placement adjacent at least one of the semilunar valve annuli to stabilize and facilitate operation of the semilunar valve. |
2. | The activation device of claim 1, wherein said stint comprises a septal splint to stabilize a septal wall ofthe natural heart. |
3. | The activation device of claim 1, wherein said stint comprises a connector element joining said first and second rings. |
4. | The activation device of claim 1 , wherein said stint comprises a connector element joining said first ring and said splint. |
5. | The activation device of claim 1, wherein said stint comprises a connector element joining said second ring and said septal splint. |
6. | The activation device of claim 1, wherein said stint comprises a first connector element joining said first ring and said septal splint, and a second connector joining said second ring and said septal splint. |
7. | The activation device of claim 1 , further comprising: (a) a yoke for placement around a portion of the exterior surface of the natural heart in general alignment with said natural heart; and (b) at least one cord connecting said stint to said yoke. |
8. | The activation device of claim 7, wherein said yoke is sized and configured for placement adjacent at least a portion of an atrioventricular groove ofthe natural heart. |
9. | The activation device of claim 7, wherein said yoke is sized and configured for placement adjacent at least a portion of an interventricular groove ofthe natural heart. |
10. | The activation device of claim 9, wherein said yoke is sized and configured for placement adjacent at least a portion ofthe anterior and posterior portions of said interventricular groove. |
11. | A mechanical ventricular activation device for use with a natural heart, said device comprising: (a) a stint for placement within the interior volume of a natural heart adjacent cardiac tissue thereof; (b) a yoke for placement around a portion of the exterior surface of the natural heart in general alignment with said natural heart; (c) at least one cord connecting said stint to said yoke; and (d) an activator attached to said yoke. |
12. | The device of claim 11, wherein said yoke comprises, an arm and; a plurality of bands connected to said arm. |
13. | The device of claim 12, wherein said plurality of bands extend away from said arm. |
14. | The device of claim 13, wherein said plurality of bands extend radially away from the distal end of said arm. |
15. | The device of claim 13, wherein said plurality of bands extend perpendicularly away from the distal end of said arm. |
16. | The device of claim 1 1, wherein said stint comprises a first ring for placement adjacent at least one of the atrioventricular annuli to stabilize and facilitate operation of a atrioventricular valve ofthe natural heart. |
17. | The device of claim 1 1, wherein said stint comprises a second for placement adjacent at least one ofthe semilunar annuli tostabilize and facilitate operation of a semilunar valve ofthe natural heart. |
18. | The device of claim 11 , wherein said stint comprises a septal splint for stabilizing a septal wall ofthe natural heart. |
19. | The activation device of claim 1 1, wherein said stint comprises a connector element joining said first and second rings. |
20. | The device of claim 11 , wherein said stint comprises a connector element joining said first ring and said splint. |
21. | The device of claim 11 , wherein said stint comprises a connector element joining said second ring and said septal splint. |
22. | The activation device of claim 1, wherein said stint comprises a first connector element joining said first ring and said septal splint, and a second connector joining said second ring and said septal splint. |
23. | A method for mechanically deforming cardiac tissue, comprising the steps of: (a) providing a cardiac tissue activation device, further comprising a stint for placement along a portion of the interior surface ofthe cardiac tissue, a yoke for placement around a portion ofthe exterior surface ofthe cardiac tissue, at least one cord connecting said stint to said yoke, and an activator; (b) deforming a portion ofthe cardiac tissue by movement of said stint; and (c) releasing said activator from deforming said stint. |
24. | The method of claim 23, further comprising the step of repeating steps (b) and (c). |
25. | The method of claim 23, wherein step (b) comprises applying a torsion force to a portion ofthe cardiac tissue. |
26. | The method of claim 23, wherein step (b) comprises applying a shearing force to a portion ofthe cardiac tissue. |
27. | The method of claim 23, wherein step (b) comprises flattening a portion of the cardiac tissue. |
28. | The method of claim 23, wherein step (b) comprises applying a uniform pressure to the ventricular surface. |
David Boyd Melvin, M.D.
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a device and method for assisting in the activation
and operation of a living heart, and more specifically, for mechanically deforming cardiac
tissue such that the circulation of blood is maintained.
BACKGROUND OF THE INVENTION
The natural heart, and specifically, the cardiac tissue ofthe natural heart can fail
for various reasons to a point where the natural heart cannot provide sufficient circulation
of blood for a body so that life can be maintained. As a solution for the failing natural
heart, several attempts have been made in the past to provide a device to maintain
circulation.
One such approach has been to either assist or to entirely replace the existing
natural heart in a patient with an artificial heart, or to transplant a natural heart from
another human into a patient. Several drawbacks have limited use of prior devices to
applications having far too brief of a time period to provide a real lasting benefit, and to
transplant use in a tiny fraction of those afflicted with heart disease or malfunction.
A particular problem stems from the fact that the materials used for the interior
lining of the chambers of an artificial heart are in direct contact with the circulating
blood, which can enhance undesirable clotting of the blood, build up of calcium, or
otherwise inhibit the blood's normal function. Hence, thromboembolism and hemolysis
could occur with greater ease. Additionally, an artificial heart lining can crack, which
inhibits performance, even if the crack is at a microscopic level.
The transplant procedure requires removing an existing organ (i.e., the natural
heart) for substitution with another organ (i.e., another natural heart) from another
human, or potentially, from an animal. Before replacing an existing organ with another,
the substitute organ must be "matched" to the recipient, which can be, at best, difficult
and time consuming to accomplish. Furthermore, even if the transplanted organ matches
the recipient, a risk exists that the recipient's body will reject the transplanted organ and
attack it as a foreign object. Moreover, the number of potential donor hearts is far less
than the number of patients in need of a transplant. Although use of animal hearts would lessen the problem with fewer donors than recipients, there is an enhanced concern with
rejection ofthe animal heart.
In an effort to use the existing natural heart of a patient, other attempts have been
made to wrap skeletal muscle tissue around the natural heart to use as an auxiliary
contraction mechanism to pump the natural heart. As currently used, skeletal muscle
cannot alone typically provide sufficient and sustained pumping power for maintaining
circulation of blood through the circulatory system of the body, especially for those
patients with severe heart failure.
Still another concept for maintaining the existing natural heart as the pumping
device involves enveloping a substantial portion ofthe natural heart, such as the entire
left and right ventricles, with a pumping device for rhythmic compression. Although
somewhat effective as a short term treatment, the pumping device has not been suitable
for long term use. Typically, a vacuum pressure is needed to overcome cardiac
tissue/wall stiffness so that the chambers can return to their original volume and refill
with blood. This "active filling" of the chambers with blood limits the ability of the
pumping device to respond to the need for adjustments in the blood volume pumped
through the natural heart, and can adversely affect the circulation of blood to the coronary
arteries. Natural heart valves are quite sensitive to wall and annular distortion, and
movement patterns that reduce a chamber's volume do not necessarily facilitate valve
closure (which can lead to valve leakage). Another major obstacle with long term use of
such pumping devices is the deleterious effect of extensive mechanical contacting of
living internal surfaces (endocardium). In certain cases, this coaption of endocardium
tissue is probably mechanically necessary for a device that encompasses both ventricles
to produce independent output pressures, but it can compromise the integrity ofthe living
endothelium.
Another device developed for use with an existing heart for sustaining the
circulatory function of a living being and the pumping action of the natural heart is an
external bypass system, such as a cardiopulmonary (heart-lung) machine. Typically,
bypass devices of this type are complex and large, and, as such, are limited to short term
use in an operating room during surgery, or to maintaining the circulation of a patient
while awaiting receipt of a transplant heart. The size and complexity effectively prohibit
use of bypass systems as a long term solution, as they are rarely even portable devices.
Furthermore, long term use of a heart lung machine can damage the blood cells and blood
borne products, resulting in post surgical complications such as bleeding,
thromboembolism function, and increased risk of infection.
Consequently, none of the previous available techniques or devices for
maintaining circulation of blood provided an adequate or practical long-term use device
or technique for adequately maintaining sufficient blood pressure and circulation of blood
through the circulatory system ofthe body.
SUMMARY OF THE PRESENT INVENTION
It is the object of the present invention to provide a device and method for
activation of a natural heart that provides different independent pressures to the left and right side of the natural heart.
It is another object ofthe present invention to provide a device and method for
activation of a natural heart that minimizes damage to the coronary circulatory and the endocardium (lining tissue).
It is still a further another object ofthe present invention to provide a device and
method for activation of a natural heart that allows one or more ofthe heart chambers
to rapidly and passively refill at low pressure after an activation stroke.
Another object ofthe present invention is to provide a device and method for the
activation of a natural heart that supports and maintains competence ofthe heart valves
so the heart valves can function as designed.
Still another object ofthe present invention is to provide a device and method for
the activation ofthe heart that functions at the proper rate.
Yet another object ofthe present invention is to provide an apparatus and method
for the activation of a natural heart on a long term basis.
It is yet still an object ofthe present invention to provide a device and method for
the activation of a natural heart to provide an implant device that does not require
removal of an existing natural heart.
Additional objects, advantages, and other features ofthe present invention will
be set forth and will become apparent to those skilled in the art upon examination ofthe
following, or may be learned with practice ofthe invention.
To achieve the foregoing and other objects, and in accordance with the purpose
herein, the present invention comprises an activator device for use with a natural heart
having an internal stint for placement within the interior volume of a natural heart adjacent cardiac tissue. The device also includes a yoke for placement around a portion
of the exterior surface of the natural heart in general alignment with the stint and is
connected to the stint by at least one cord.
Preferably, the activator device includes a first ring for placement around at least
one ofthe atrioventricular valve annuli, a second ring for placement around at least one
ofthe outflow valve or semilunar annuli, and a septal splint having a frame and sutures
in a net-like configuration to stabilize the septal wall between chambers ofthe natural
heart. The first ring, second ring, and the septal splint are connected to each other using
fastening elements.
In a preferred embodiment, the yoke is sized and configured for placement
adjacent at least a portion of the interventncular groove, preferably adjacent at least a
portion of the anterior and posterior portions of the interventricular groove, and more
preferably adjacent at least a substantial portion ofthe anterior and posterior portions of
the interventricular groove. In another embodiment, the yoke is sized and configured for
placement adjacent at least a portion ofthe atrioventricular groove.
The present invention also includes an activator attached to the yoke for
deforming the natural heart, which preferably includes a hydraulic lateral arm.
The present invention also includes a method for cardiac tissue deformation using
the above-described device. The activator deforms a portion of the cardiac tissue by
moving an arm from a relaxed condition to an activated condition. As the activator is
pressing against the natural heart, the volume of at least one chamber ofthe natural heart is decreased so that blood is pumped out of the natural heart and into the circulatory
system. Thereafter, the activator releases from against a portion of the cardiac tissue
returns to the relaxed condition. The combination ofthe stint and yoke assist in returning
the volume ofthe chamber so that at least one ofthe chambers ofthe natural heart refills
with blood and thus, the steps can be repeated.
Different forces can be applied to a natural heart for reducing the volume of at
least one ofthe chambers. These forces can include applying a torsion force or a shearing
to the natural heart, flattening a portion ofthe cardiac tissue, applying a uniform pressure
to the natural heart, and/or applying an indentation against at least one point on the
exterior wall ofthe natural heart.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly claiming the present invention, it is believed the same will be better understood
from the following description taken in conjunction with the accompanied drawings in
which:
Fig. 1 is a partial frontal anterior perspective view of an exemplary natural heart;
Fig. 2 is a perspective view of an internal stint and exterior yoke made in
accordance with the present invention;
Fig. 3 is a partial cross-sectional view of a natural heart with a septal splint made
in accordance with the present invention placed within a natural heart;
Fig. 4 is a partial frontal perspective view of a natural heart with an external yoke
placed on a natural heart;
Fig. 5 A is a frontal perspective view of one embodiment ofthe external yoke and
activator ofthe present invention;
Fig. 5B is a frontal perspective view of another embodiment of an external yoke
and activator ofthe present invention;
Fig. 6 is a top sectional schematic view of a natural heart with an internal splint
and an external yoke ofthe present invention illustrated being connected by transmural
cords;
Fig. 7A is a partial schematic view of an exemplary activator of the present
invention in a relaxed condition; and
Fig. 7B is a partial schematic view of an exemplary activator of the present
invention in an activated condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the figures in detail wherein like numerals indicate the same
elements throughout the views, a natural heart, generally indicated in Figure 1 as 10, has
a lower portion comprising two chambers, namely a left ventricle 12 and a right ventricle
14, which function primarily to supply the main force that propels blood through the
circulatory system. A natural heart 10 also includes an upper portion having two
chambers, a left atrium 16 and a right atrium 18, which primarily serve as an entry way
to the left and right ventricles 12 and 14, respectively, and assist in moving blood into the left and right ventricles 12 or 14. The interventricular wall of cardiac tissue separating
the left and right ventricles 12 and 14, respectively, is defined by an interventricular
groove 20 on the exterior wall of the natural heart 10. The anterioventricular wall of
cardiac tissue separating the lower ventricular region from the upper atrium region is
defined by anterioventricular groove 22 on the exterior wall ofthe natural heart 10.
Generally, the ventricles are in fluid communication with the atria through an
atrioventricular valve. More specifically, the left ventricle 12 is in fluid communication
with the left atrium 16 through the mitral valve, while the right ventricle 14 is in fluid
communication with the right atrium 18 through the tricuspid valve. Generally, the
ventricles are in fluid communication with the circulatory system (i.e., the pulmonary
and peripheral circulatory system) through semilunar valves. More specifically, the left
ventricle 12 is in fluid communication with the aorta 26 of the peripheral circulatory
system, through the aortic valve, while the right ventricle 14 is in fluid communication
with the pulmonary artery 28 ofthe pulmonary, circulatory system through the pulmonic
valve.
By way of a non-limiting example, the present invention will be discussed in
terms of embodiments that are used to primarily assist in the activation and operation of
the left ventricular portion of the natural heart 10, however, it is noted that the present
invention can also be used to assist in the activation and operation of other portions of
the natural heart 10, such as the atria, or the right ventricular portion ofthe natural heart
10. The present invention is a mechanical activator, illustrated in Figure 2 as 50, which
includes an internal stint 52. Furthermore, the present invention includes an external
yoke 70 fixed to the internal stint 52 by transmural cords 86. The internal stint 52 is sized
and configured for placement within the interior volume of the natural heart 10, and
includes a generally triangular shaped frame 53 that can be assembled from a plurality
of interlocking struts, preferably an anterior, a posterior and a basal strut. The stint 52
also includes at least two separate ring structures, namely a first ring 56 sized and
configured for placement adjacent the atrioventricular valve annuli, and preferably
suprajacent the mitral valve annuli in the left atrium 16, and a second ring 58 sized and
configured for placement adjacent the semilunar valve annuli preferably subjacent the
aortic valve annuli in the left ventricle 12.
Figure 3 further illustrates a septal splint 54, which can include one or more
strands of sutures affixed to the frame 53 through loops positioned on the frame 53,
preferably the loops are affixed to the inner portion of frame 53, and more preferably,
at about 1.5 cm intervals. The splint 54 can take the form of a tennis racket-like shaped
configuration or a snowshoe like shaped configuration to brace or stabilize one side of
the septum, preferably the right side ofthe interventricular septum without distortion of
the chordae. Preferably, the septal splint 54 is positioned by stringing a heavy
monofilament polypropylene suture, such as a #5 polypropylene suture, under, through,
and behind the trabeculae, and through the loops as will be discussed later in great detail. The first and second rings 56 and 58 and the septal splint 52 are attached at least to each
other using a connector element 59, such as a pin to assist in maintaining the relative
position so that the first and second rings 56 and 58, respectively, and the splint 52 are
supported while the natural heart 10 is being activated.
So that the components of the stint 52 (e.g., the septal splint 54 and first and
second rings 56 and 58) are not totally rigid and can exhibit an elastic quality, the
components are preferably made of a stiff coil spring material covered with braided
polyester. Localized adjustments can be made to the elasticity ofthe various components
ofthe stint 52 to reduce the potential for problems, such as damaging the cardiac tissue
or compromising the coronary circulation.
As illustrated in Figure 4, the device 50 also includes an external yoke 70 for
placement around a portion of the exterior surface of a natural heart 10. The generally
stirrup shaped yoke 70 restricts free motion of the natural heart 10 so that the natural
heart 10 can be activated. Preferably, the yoke 70 can be between about 1 and 2 cm wide
and includes a semi-rigid collar portion, preferably made of polypropylene, for providing
rigidity to the yoke 70. Additionally, the yoke 70 can include a gel-filled cushion portion
that is positioned immediately adjacent exterior surface of the natural heart 10 for
providing equalized pressure over the irregularities in the epicardial surface ofthe natural
heart 10, and preferably, any of the coronary arteries 30 within each region under the
yoke 70. Preferably, the yoke 70 is sized and configured for placement adjacent at least
a portion of the atrioventricular groove 22, more preferably, at least a portion of the
anterior and posterior portions ofthe interventricular groove 20, and most preferably, at
least a substantial portion of the anterior and posterior portion of the interventricular
groove. In yet another embodiment, the yoke 70 is sized and configured for placement adjacent at least a portion ofthe atrioventricular groove 22.
Referring now to Fig. 6, general alignment of the yoke 70 is maintained by at
least one transmural cord 86, and preferably, a plurality of cords 86 that penetrate the
walls ofthe natural heart 10 and connect to the stint 52. The cord 86 is preferably made
of a heavy braided, polymer-impregnated polyester suture core (such as # 5 Ethiband®
by Ethicon, Inc.) covered in the intermyocardial portion with a braided sleeve of
polyester yarn to promote firm tissue growth around the cord 86. When it is necessary
to utilize more than one cord 86 with the present invention, spacing of the cords 86
should preferably be at intervals of between about 15 mm to 20 mm along the yoke 70,
from the septal splint 54 and the first ring 56 extending obliquely outwardly toward the
left ventricle exterior wall for insertion into the left ventricle margin of the yoke 70.
More preferably, the cords 86 should be positioned for avoiding contact with the
coronary vessels 30. The cords 86 vary in length such that the splint 54 and first ring 56
are oriented beneath the gel-filled cushion portion while the septum stint 52 and the first
ring 56 are held stable in general alignment with the natural heart 10, and are generally
not allowed to move away from the ventricular exterior wall when pressure is applied to a natural heart 10 via by activator 74.
As mentioned above, the present invention also includes an activator 74 attached
to at least a portion of the yoke 70, preferably the apical portion 70a, as illustrated in
Figures 5A and 5B. The activator 74 includes a lateral flexible arm 75 generally having
an "L" shaped configuration that extends approximately two-thirds of the distance
between the apical portion 70a and base portion 70b ofthe yoke 70.
Connected to the arm 75 is at least one, and preferably a plurality of, bands 84 extending away from the arm 75 sized and configured for placement adjacent the exterior
surface ofthe natural heart 10. The distal ends ofthe bands 84 are typically affixed and
secured along portions of yoke 70.
One embodiment of the yoke 70 and activator 74 is illustrated in Figure 5 A in
which the bands 84 extend perpendicularly away from the arm 75 and connect to the
anterior and posterior portions of yoke 70. In another embodiment ofthe yoke 70 and
activator 74 as illustrated in Figure 5B, bands 84 extend radially away from the distal
end ofthe arm 75.
Referring now to Figures 7A and 7B, the activator 74 preferably has a hydraulic
lateral arm 75 having a tubed-shape corrugated configuration with rings 77 affixed to the
inner aspect of each corrugation. A plurality of longitudinally extending cords 76,
preferably three or more, are affixed to the inner portion of arm 75, preferably the distal
end of arm 75 and also preferably to each of the rings 77. The cords 76 can vary in
length, especially between the fixation points to each ring 77 for controlling the
separation distance between rings 77. In fluid communication with the arm 75 via a
driveline 92 is a pump unit "P", such as pneumatic or a hydraulic pump for controlling
or altering the fluid volume within the arm 75.
Figure 7A illustrates the arm 75 in a relaxed condition when fluid pressure within
arm 75 is at or below ambient levels and where the shape of arm 75 is determined by the
external forces and the intrinsic stiffness of arm 75. To utilize the present invention,
pressure within the arm 75 can be increased, preferably above ambient levels, so that the
shape of the arm 75 is altered to an activated condition, as illustrated in Fig. 7B. The
length difference of the various cords 76 between the rings 77 controls the radius of
curvature of the arm 75 and the direction of curvature at various portions along the
longitudinal length ofthe arm 75. The amount of pressure required within the arm 75
must be sufficient to overcome the intrinsic stiffness ofthe arm 75 at ambient condition,
and to facilitate the proper deformation of both the arm 75 and bands 84 so that the
proper amount of pressure is applied to the exterior wall ofthe natural heart 10 to assist
in altering (i.e., reducing) the volume of one or more chamber of a natural heart 10 (e.g.,
the left ventricle 12) to maintain circulation ofthe blood through the circulatory system.
In a preferred embodiment, the arm 75 can be customized to apply different
pressure to different portions ofthe natural heart 10. For example, varying the diameter
of arm 75 along the longitudinal length can assist in controlling the curvature of arm 75.
Regions ofthe arm 75 needing less bending moment can have a smaller diameter and
regions ofthe arm 75 where greater bending moments are preferred can have a larger
diameter.
Various embodiments of an activator 74 can be utilized with the present invention
to achieve a change in the volume of one or more heart chambers. It is noted that any
activator 74 used with the present invention should be sufficient so that the cardiac output
of a typical adult is between about 3 1/min and about 30 1/min, and preferably between
about 5 1/min and 20 1/min.
In addition, there are various possible forces which can be used for activating, and
thus altering the chamber volumes ofthe natural heart 10. The present invention can be
utilized to flatten the exterior wall of the natural heart 10 in a plane substantially
perpendicular to the plane of the atrioventricular valves (e.g., a mitral valve) or
substantially parallel to the septum. When utilizing such a force, the activator 74 should
be configured to produce a flexion in the convex direction limited to between about 2.5
to 3.0 times the curvature value of the exterior wall of the natural heart 10 during the
diastolic portion ofthe cardiac cycle. Deflection in a concave direction is restricted only
to those bands 84 extending away from the arm 75 and connecting to the base portion 70b
of yoke 70.
Also, an activator 74 can be used to apply a uniform pressure to substantially the
entire exterior wall ofthe natural heart 10.
Furthermore, the activator 74 can be used to indent the exterior wall ofthe natural
heart 10 at more than one location, and preferably at two or three locations on either an
exterior wall or the septum in a hemispheric or hemiellipsoid profile.
Additionally, an activator 74 can apply a torsion force to at least a part of the
natural heart 10 at various angles.
In yet another embodiment, the activator 74 can apply a shearing force to a
portion ofthe lateral exterior wall, which is directed apically and is a basal sheer force
applied on the right side of the stint 52.
When the orientation ofthe arm 75 is altered from the relaxed condition, which
is illustrated in Fig. 7A, to the activated condition, which is illustrated in Fig 7B, the arm
75 and the bands 84 deform and apply pressure against the exterior wall ofthe natural
heart 10 for assisting with or facilitating activation ofthe natural heart 10 (the systolic
portion of the cardiac cycle). As a result, the volume of one or more chambers of the
natural heart 10 is reduced and blood is pumped out ofthe natural heart 10 and into the
circulatory system.
Following the activation (i.e., systolic portion ofthe cardiac cycle), the arm 75
and bands 84 release from against the cardiac tissue and return to their relaxed condition.
The combination ofthe stint 52 and the yoke 70 assists in returning the deformed portion
of the natural heart 10 back to its pre-activation volume so that it can refill with blood
during the diastolic portion of the cardiac cycle, so that the entire cardiac cycle can be
repeated.
To position the device 50 into and around an existing natural heart 10, open heart
thoracic surgery is required. Clinically, sufficient anesthesia is administered to the
patient and the thoracic cavity is opened using standard thoracic procedures.
Once the thoracic cavity is opened, circulation of blood to the natural heart 10
must be bypassed so the present invention can be inserted into the patient. Referring
initially to Fig. 2, the superior vena cava 26, the inferior vena cava (not shown), and aorta
26 are cannulated. The circulatory system is connected to a cardiopulmonary bypass
machine so that circulation and oxidation of the blood are maintained during the
procedure. By way of example, the procedure discussed in detail will be for insertion of
the present invention to assist in the activation and operation ofthe left ventricle 12.
Through an aortotomy and an interatrial groove left atriotomy, the first and
second rings 56 and 58, respectively, are inserted and sutured in position. Preferably, the
first ring 56 is positioned suprajacent the mitral annuli and the second ring 58 is
positioned subjacent the aortic annuli.
The interlocking struts ofthe septal frame 53 (e.g., anterior, posterior, basal struts)
are inserted into the right ventricle 14 through an apical ventriculotomy, a right atriotomy
with partial temporary detachment ofthe septal tricuspid leaflet of the tricuspid valve,
and an outflow tract ventriculotomy, respectively. Suture strands are then passed back and forth against the interventricular septum, threading through loops to provide a septal
splint 54. In placement of both the various struts of frame 53 and the strands that form
splint 54, care is taken to maneuver behind chordae and behind or through major
trabeculae and bases of papillary muscles. The suture strands are tied to form the net-like
configuration ofthe septal splint 54 that lies snugly against the septum, but allows it to
maintain normal rightward convexity. Separate connector elements 59, preferably pins,
are placed to joint the first ring 56 and the second ring 58, the second ring 58 and the
septal splint 54, and the septal splint 54 and the first ring 56.
Next, the left pleural cavity is opened and the yoke 70 is positioned behind the
natural heart 10. Cords 86 are assembled as 12" strands of suture with a polyester bead
fused to one end and blunt straight needle on the other. Each suture is passed through a
hole in the margin of the yoke 70, through the cardiac tissue, and preferably the
ventricular wall, and through the internal stint 52 (i.e., first ring 56 or septal splint 54)
and anchored after length adjustment, with the excess portion of the sutures cut and
removed. Cords 86 are tightened to render the intrinsically flexible stint 52 relatively taut and control bulging, preferably in a rightwardly direction.
Cardiotomies are closed, and the activator 74 is attached to the yoke 70. The
driveline 92 is attached to the drive unit "P" and all indicated monitoring lines are
positioned. Preferably, Heparin-filled Teflon-coated polyurethane 5 Fr. catheters are
brought through the posterior cervical incision into the chest and into the atrial
appendages and an identical one into a branch ofthe innominate artery. Termination of
a cardiopulmonary bypass is attempted and, if successful, the thoracotomy is closed.
An alternative method for positioning the present invention includes removing
the natural heart 10 from the patient, positioning all the components of the present
invention, as discussed above, and auto-transplanting the natural heart 10 back into the
patient using standard cardiectomy and cardiac transplant techniques known in the
industry.
Having shown and described the preferred embodiments to the present invention,
further adaptations ofthe activation device for the living heart and method of deforming
the living heart as described herein can be accomplished by appropriate modifications by
one of ordinary skill in the art without departing from the scope o the present invention.
For example, the present invention can be used with any one or even a plurality ofthe
various chambers of a living heart, and also could be used with different activators 74.
Other examples of an activator 74 usable with the present invention include a girdle
assembly that can be activated by hydraulics forces or other forces, such as an
electromagnetic for using magnets and electrical current. Several such potential
modifications have been discussed and others will be apparent to those skilled in the art.
Accordingly, the scope of the present invention should be considered in terms of the
following claims and is understood not to be limited in the details, structure and operation
shown and described in its specification and drawings.