HK1036398A - Device and method for restructuring heart chamber geometry - Google Patents

Description

Shaping device and method for heart chamber geometry

Field of the invention

The present invention relates to a device and method for treating myocarditis and/or enlarged heart, and more specifically, to a device and method for reducing wall tension of a heart chamber.

Background

The natural heart, and in particular the muscle tissue of the natural heart (e.g., the myocardium), can be rendered inoperable for a variety of reasons, such that the natural heart is unable to provide the necessary blood circulation required by the body to sustain life. More specifically, the heart and its chambers are enlarged for various causes and/or 0 causes, including: viral diseases, primary diseases, valvular diseases (coronary, arterial, and/or both), ischemic diseases, chagas diseases, and the like. As the heart and its chambers grow larger, the chamber wall tension increases and, therefore, the heart must develop greater wall tension to provide the necessary pressure to pump blood through the circulatory system. As a solution to the enlarged natural heart, attempts have been made in the past to provide a treatment that maintains circulation.

One approach is to replace the patient's existing natural heart with an artificial heart or a ventricular assist device. A particular problem arises in the use of artificial hearts and/or auxiliary devices, in fact, in that the material used as a lining for the chambers of the artificial heart, which is in direct contact with the circulating blood, increases undesired blood clotting, increases the calcium content and also influences the normal function of the blood. Therefore, thrombosis and hemolysis are more likely to occur. In addition, the liner or ventricular assist device of the artificial heart can crack, which can affect performance even at a subtle level. Moreover, these devices must be powered by an inconvenient external power source. These drawbacks limit the use of these devices to applications where short term use does not provide true sustained use.

Another alternative is to transplant another human or animal heart to the patient. This transplantation procedure requires removal of an existing organ (i.e., the natural heart) and replacement with another organ (i.e., another natural heart) of another person or possibly an animal. Before replacing an existing organ with another, the replacement organ must be "matched" to the recipient, which is also difficult and time consuming to accomplish in the best case. In addition, even if the transplanted organ matches the recipient, there is a risk 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 much smaller than the number of patients requiring transplantation. Although the use of animal hearts can alleviate the contradiction of fewer donors than recipients, the rejection of animal hearts is more of a concern.

In an effort to use the patient's existing natural heart, attempts have been made to reduce the tension of the heart by cutting away portions of the heart wall, such as by removing portions of the heart wall during a partial left ventricular incision procedure (Batista procedure). A wedge-shaped portion of the ventricular muscle from the top to the bottom of the heart is excised. By reducing the chamber volume, the radius, and thus the chamber wall tension, is reduced. However, there are certain drawbacks in such an approach. First, depending on the amount of myocardial tissue that is excised, the valve (i.e., the coronary valve) may need to be repaired or replaced. Secondly, this method is both internal and external to the patient. Thus, during and after surgery, significant blood loss and bleeding is inevitable. Moreover, the process is irreversible as seen by those of ordinary skill in the industry.

Another device used with existing hearts to maintain the circulatory function and the pumping action of the natural heart in a living person is an external bypass system, such as a cardiopulmonary machine (heart-lung). This form of bypass system is generally complex and large, and therefore its use is limited to short-term use in an operating room in emergency or to maintain the circulation of the patient while waiting to receive a transplanted heart. The bypass system is rarely a portable device and size and complexity greatly limit its application as a long-term solution. Moreover, the long-term use of these systems can damage blood cells and blood loads, leading to subsequent surgical complications such as bleeding, thrombotic effects, and increased risk of infection.

The medicine is used for auxiliary treatment of cardiomyopathy, such as vasodilator. For example, digoxin enhances the contractility of the heart, thereby increasing the emptying of the chamber during systolic pumping. On the other hand, certain drugs, such as beta-receptor blocking drugs, which reduce the size of the heart chamber, may also reduce cardiac contractility. When myocardial contractility decreases, diastolic blood pressure increases and the heart tends to enlarge, and other drugs, such as angiotensin converting enzyme inhibitors (e.g., elalopril), help to reduce this tendency. Many of these drugs have side effects, such as excessive lowering of blood pressure, which are detrimental to long-term treatment.

As noted above, current effective therapies, procedures, drugs and devices for treating advanced cardiomyopathy have a number of drawbacks that complicate the method or device. Current procedures and treatments are either overly deep in the body, effective only for a short period, or have adverse side effects that interfere with cardiac efficacy. There is a need in the industry for an apparatus and method that can be used with existing hearts to provide a practical, long-term use of the apparatus and method to reduce heart wall tension and thus enhance the pumping efficiency of the heart.

Technical scheme

It is an object of the present invention to provide a device and method for treating cardiomyopathies that overcomes the above-mentioned problems and deficiencies in the thoracic medical field.

It is another object of the present invention to provide a device and method for treating cardiomyopathy that minimizes damage to the coronary circulation and endocardium.

It is a further object of the present invention to provide an apparatus and method for treating cardiomyopathy that maintains cardiac stroke volume.

It is another object of the present invention to provide a device and method for treating cardiomyopathies that maintains the capacity of the heart valve to make the heart valve as effective as desired.

It is a further object of the present invention to provide a device and method that can improve the pumping efficiency of the heart.

It is a further object of the present invention to provide a device and method for treating cardiomyopathy that can be used for a long period of time.

It is yet another object of the present invention to provide an apparatus and method for treating cardiomyopathies without the need to remove any portion of the existing natural heart.

It is a further object of the present invention to provide an apparatus and method for treating enlarged cardiomyopathies that directly reduces the effective radius of the heart chamber during systole and diastole.

Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention.

To achieve the foregoing and other objects, and in accordance with the purpose herein, the present invention includes a fixation device for a heart having a plurality of components positioned adjacent an epicardial surface. The components are connected by at least one connector and are secured in spaced apart relation to one another such that a portion of the core wall is displaced internally.

These components may be configured as rectangles and preferably include a curved inner surface. In one embodiment, the device may have first and second components mounted in spaced 180 degrees from each other. The first component is formed adjacent to the front outer side surface of the chamber and the second component is formed adjacent to the rear middle surface of the chamber.

In another embodiment of the device having first, second and third components, the first, second and third components are mounted 120 degrees apart from each other. The first component is formed to be mounted adjacent to the front diaphragm of the chamber, the second component is formed to be adjacent to the rear diaphragm of the chamber, and the third component is formed to be adjacent to the rear outer side of the chamber.

The device may also include a liner adjacent the inner surface, preferably between the assembly and the endocardial surface. The pad may be made of a low durometer solid polymer or plastic, or it may be a gel-filled or liquid-filled cushion.

The connector of the present invention comprises a string, such as a high knit polymer saturated polyester fiber suture core with a polyester fiber sheath, or a high molecular polypropylene monofilament, or a string of expanded polytetrafluoroethylene (PTFE, such as Gortex , trade mark w.l.gore & co.), which may be threaded through heart tissue and/or the cavity. The connector of the present invention may also include a conventional rigid needle or rod which is used to pass through and connect the components.

In a preferred embodiment, the device of the invention comprises at least one fixing means on the assembly, which is intended to be inserted into the heart. The anchoring device may be in the form of a needle that passes through the heart wall, or it may be in the form of a knob that is anchored near the endocardial surface and a chord that connects the assembly and knob.

In another embodiment, the device of the present invention may comprise a generally horseshoe-shaped strap-like device having a first rigid portion configured to be mounted adjacent the antero-lateral portion of the chamber, a second rigid portion configured to be mounted adjacent the posterior portion of the chamber, and a flexible portion (in the tangential plane) between the first and second portions and configured to be mounted around the apex of the heart. A bottom connector is configured to fit between the first and second rigid portions of the band-like device, preferably configured to couple to the atrioventricular valve annulus.

In use, the present invention may reduce chamber wall tension in one of the heart chambers. A securing strap is secured to the heart so that a chamber of the heart is formed as at least two contiguous connected portions in the form of flattened ellipsoids having a smaller minimum radius than the chamber prior to reshaping. In this way, the inner strap displaces at least two portions of the chamber wall without being positionally constrained.

Brief Description of Drawings

While the claims particularly point out and distinctly claim the specific disclosure of the present invention, it is believed that the invention will be better understood from the following description taken in conjunction with the accompanying drawings.

FIG. 1 is a partial front view of a natural heart;

FIG. 2 is a longitudinal cross-sectional view of a natural heart and blood vessels entering and exiting the heart;

FIG. 3 is a horizontal cross-sectional view of an unconstrained left ventricle of a natural heart;

FIG. 4 is a perspective view of a device made in accordance with the present invention and positioned in the left ventricle;

FIG. 5 is a cross-sectional view of the device taken along line 5-5 of FIG. 4;

FIG. 6 is a perspective view of another embodiment of a device made in accordance with the present invention and positioned in the left ventricle;

FIG. 7A is a partial horizontal cross-sectional view of a liner inserted between the epicardial surface and the component at diastole;

FIG. 7B is a partial horizontal cross-sectional view of a liner inserted between the epicardial surface and the component during systole;

FIG. 8 is a vertical sectional view of another embodiment of a device made in accordance with the present invention and positioned in the left ventricle;

FIG. 9 is a perspective view of yet another embodiment of a device made in accordance with the present invention and positioned in the left ventricle;

FIG. 10 is a vertical cross-sectional view of the embodiment of FIG. 9;

FIG. 11A is a perspective view of the embodiment of FIGS. 9-10, shown undeformed;

FIG. 11B is a perspective view of the embodiment of FIG. 11A after the device has been flexed due to ventricular contraction;

FIG. 12 is a vertical cross-sectional view of one embodiment of a secondary fastener made in accordance with the present invention; and

FIG. 13 is a vertical cross-sectional view of another embodiment of a secondary fastener made in accordance with the present invention.

Detailed description of the embodiments

Referring now in detail to the drawings wherein like elements are designated by like reference numerals, there is shown in fig. 1 and 2 an exemplary natural heart designated generally at 10 having a lower portion comprising two chambers, referred to as the left ventricle 12 and the right ventricle 14, which primarily function to provide a primary force for propelling blood through two circulatory systems, one of which is referred to as the pulmonary circulatory system, for propelling blood into and out of the lungs and one of which is referred to as the superficial circulatory system, for propelling blood through other parts of the body. The natural heart 10 also includes an upper portion comprising two chambers including a left atrium 16 and a right atrium 18, the left and right atria primarily providing access to the left and right ventricles 12 and 14, respectively. An inner wall 40 of the heart tissue 32 separates the left and right ventricles 12 and 14, and an atrial wall 42 of the heart tissue 32 separates the lower ventricular zone from the upper atrial zone.

Typically, each of the left and right ventricles 12 and 14 has a cavity 13 and 15, respectively, with the cavities 13 and 15 being in fluid communication with the cavities 17 and 19 of the atria (e.g., 16 and 18) respectively, via an atrial chamber valve 50 (closed in fig. 2). More specifically, the left ventricle chamber 13 is in fluid communication with the left atrium chamber 17 through a mitral valve 52, while the right ventricle chamber 15 is in fluid communication with the right atrium chamber 19 through a tricuspid valve 54.

Typically, the ventricular chambers (e.g., 13 and 15) and the blood circulation system (i.e., pulmonary blood circulation and superficial blood circulation) are in fluid communication with each other via a half-moon valve 44 (shown in an open state in FIG. 2). More specifically, the left ventricular chamber 13 is in fluid communication with the aorta 26 of the superficial blood circulation system via an aortic valve 46, while the right ventricular chamber 15 is in fluid communication with the pulmonary artery 28 of the pulmonary blood circulation system via a pulmonary valve 48.

Blood returns to the heart 10 through the atria (e.g., 16 and 18). More specifically, blood is communicated and delivered in fluid communication as the superior vena cava 22 and inferior vena cava 24 return from the body surface blood circulatory system to the right atrium 18 and right atrial chamber 19. As pulmonary veins 30 return from the pulmonary blood circulation system to the left atrium 16 and left atrial chamber 17, blood is communicated and delivered in fluid communication.

The heart 10 is surrounded in the chest by a double-walled sac, commonly referred to as the pericardium. The inner layer of the pericardium is the inner pericardium or epicardium, and the outer layer is the parietal pericardium. In other materials, the structure of the heart 10 generally consists of heart muscle or tissue 32, the tissue 32 having an outer surface, commonly referred to as the epicardial surface 34, and an inner surface, or endocardial surface 38, with the endocardial surface 38 generally defining chambers (e.g., the individual ventricular chambers 13 and 15, and the individual atrial chambers 17 and 19). Coronary arteries 36 on the epicardial surface 34 of the heart 10 supply blood and nutrients (e.g., oxygen) to the heart 10 and its cardiac tissue 32.

By way of non-limiting example, the present invention is primarily directed to assisting in the repair and/or surgery of the left ventricle (e.g., 12) of the heart 10 in accordance with the discussion of the embodiments, but it should be noted that the present invention may also be used to assist in the repair and/or surgery of other portions of the natural heart 10, such as either the atria (16 and/or 18) or the right ventricle (e.g., 14) of the natural heart 10.

Referring now to FIG. 3, the chamber of the heart 10 including the left ventricle 12 is generally in the shape of a hollow flattened ellipsoid having a center point "C" on any circular cross-section perpendicular to the major axis of the ellipsoid₁"and one from the center point C₁Radius "R" extending to endocardial surface 38₁". The tissue 32 of the heart 10 has a thickness "w" that is the distance between the epicardial surface 34 and the endocardial surface 38.

The fixation device and orthopedic appliance 60 of the present invention shown in fig. 4 and 5 is better shaped and positioned relative to the natural heart 10, replacing at least two central portions of the cardiac tissue 32 (see fig. 5) from the free state position shown in fig. 3. By centrally displacing the heart tissue 32, the shape of the cavity of the heart 10 (e.g., the left ventricle 12) is restored, from a generally hollow flattened shapeThe ellipsoid (see figure 3) becomes a cavity shaped like a continuous communication of at least two flattened ellipsoid portions (see figure 5). In such a prosthetic heart 10, each flattened ellipsoid has an adjustable radius "R₂”，R₂Preferably the specific radius "R₁"short".

The device or orthopaedic instrument 60 may be stationary and incapable of stimulating or pumping the heart 10, and instead may replace and maintain a portion of the cardiac tissue 32 in a generally predetermined fixed position as the heart 10 continues to contract (e.g., pulsate) and pump blood through the heart chamber and the body's blood circulatory system.

When shaped to resemble at least two continuous, flattened ellipsoidal portions, the device 60 may include at least two members 62 to assist in reorganizing or reconstructing the left ventricle 12, the members 62 preferably being spaced 180 degrees apart on the epicardial surface 34 to reorganize or reconstruct the left ventricle 12. One of the components 62 is adjacent to the anterior surface of the cavity (e.g., left ventricle 12) and the other of the components 62 is configured to fit adjacent to the posterior medial surface of the cavity (e.g., left ventricle 12).

Each element 62 includes a contact surface or an inner surface 64 that is preferably curved to be convex outwardly in a collinear plane (see fig. 5) and to be convex inwardly in a transverse plane (see fig. 4) so that the resulting element 62 is mounted in close proximity to or on the epicardial surface 34 to thereby establish intimate contact even during contraction or beating of the heart 10. The component 62 and its inner surface 64 should be shaped so that it maintains line contact with the portion of the epicardial surface 34 where contact is established and so as to alter or replace the cardiac tissue 32 in a transverse plane from the unreinforced inwardly projecting shape (see fig. 3) to the reconfigured outwardly projecting shape (see fig. 5). The inner surface 64 is provided as a smooth curve with sides 67 so that the epicardial surface 34 slides along the assembly 62 during contraction and expansion of the heart 10.

The components 62 should preferably be made of a lightweight, rigid material that has a low bending strain at the desired stress level so that the material has sufficient wear resistance when the heart 10 is beating during use and retains the desired shape when used in close proximity to the heart 10. Examples of materials that can be used for the assembly 62 include any biocompatible material, such as a metal including titanium or stainless steel, or a suitable polymer including polyacetal or a high molecular weight monofilament polyethylene.

The assembly 62 may be of any desired shape and may vary depending on the body structure and desired application. The member 62 preferably has rounded edges, and is generally a rectangular shaped body having a length that extends in cross-section or along the long axis of the chamber (e.g., between the atrioventricular notch 43 (see fig. 1) and the apical portion 20 of the heart 10). In a preferred embodiment, the length of the assembly 62 may vary between about 50% and 100% of the longitudinal axis of the chamber (e.g., 12). From about 4cm to about 12cm, with an optimum variation of about 80% of the longitudinal axis of the cavity (e.g., 12). In addition, the assembly 62 has a thickness that varies between about 1mm to 10mm depending on the modulus and strength of the material selected. When metal is used for the assembly 62, the thickness is preferably about 1mm, and when high strength polymer is used, the thickness of the assembly 62 varies from about 6mm to about 8 mm.

As described in detail below, assembly 62 preferably has one or more apertures 63 extending through its body (e.g., from inner surface 64 to outer surface 65) for inserting a connector 70 through or into the apertures to connect or secure assembly 62. Providing a series of holes 63 along the length of the assembly 62 ensures that the customizability of the present invention is increased under a particular desired use. The bore 63 preferably has an enlarged opening 66 in the outer surface 65 of the component 62, as discussed below, to accommodate placement of the connector 70 therein.

Returning now to FIG. 6, if desired, three separate assemblies 62 may also be provided as three serially interconnected flattened ellipsoids to assist in reorganizing or reconfiguring the chamber 12, in accordance with the present invention. In such an embodiment, the members 62 are spaced 120 ° apart around the epicardial surface 34. For example, a first component 62 is preferably formed adjacent to the anterior membrane portion of the chamber 12, a second component 62 is preferably formed adjacent to the posterior membrane portion of the chamber 12, and a third component 62 is preferably formed adjacent to the posterior lateral portion of the chamber 12.

To allow the epicardial surface 34 to be separated from the adjacent component 62, or to not create a substantial negative pressure in the side portion 67 of the inner surface 64, a liner 56 may be positioned and/or inserted between the epicardial surface 34 and the inner surface 64. As shown in fig. 7A and 7B, the pad 56 is a liquid or gel filled pad or cushion that normally occupies space laterally away from the assembly 62 and the side portions 67 of the inner surface 64 when the heart 10 is in a relaxed state. However, as the heart 10 contracts and the walls shorten (see fig. 7B), the epicardial surface 34 is generally peeled circumferentially (decreasing the lumen radius) away from the assembly 62 and the side portions 67 of the inner surface 64 so that the liquid or gel in the liner 56 fills the space so that the inner surface 64 and epicardial surface 34 remain in contact and achieve focal arrest, and thus the cavity 12 is reconfigured as described in detail above.

In one embodiment, the gasket 56 is a closed system. Alternatively, it is contemplated that the pad 56 may be configured to allow for the addition or removal of liquids and/or gels to enhance the desired functionality of the device 60 of the present invention. For example, one or more lines 58 in the pad 56 are in fluid communication with a chamber. The line 58 may extend from the pad 56 to an injection port 59, which may be placed in the subcutaneous tissue or elsewhere as desired due to the increased access. As will be appreciated by those skilled in the art, a standard syringe and needle or other device may be used to inject the liquid or gel into the injection port 59 to increase the size of the gasket 56 and/or its internal pressure as desired. Alternatively, the liquid or gel may be withdrawn as desired.

Additionally, the liner 56 may be a low durometer polymer such as plastic or other material (e.g., rubber). As detailed above, for the application, the material should be capable of providing and maintaining the assembly 62, and more specifically its inner surface 64, in contact with the epicardial surface 34, and thereby achieve the desired reshaping of the heart 10 as the heart 10 beats or deforms.

In order to maintain the components 62 in a fixed spaced apart relationship with respect to one another, and to bring them adjacent to or secured to the epicardial surface 34 as desired, the components 62 are connected or otherwise connected by one or more connectors 70. The connector 70 may employ various mechanical connectors used in the industry to attach and secure the prosthetic device within the body. Examples of connectors 70, which will be discussed in detail below, include a string (e.g., 72), a peg (e.g., 73, 76), and the like.

Returning again to fig. 4 and 6, the assemblies 62 are connected or tied together with one or more generally flexible extension strings 72 to maintain them in the desired position. In one embodiment, the chord 72 is sized to be inserted through an aperture 63, through the heart tissue 32, across the chamber 13, and through the heart tissue 32 on the other side of the chamber 12 to connect with the corresponding component 62 through the aperture 63. The string 72 may be attached or secured to the assembly 62 using means and techniques known in the industry, such as providing a surgically applied suture knot at or near the end of the string 72 as desired, and then concealed within the stoma opening 66.

The string 72 is generally composed of a biocompatible material that better inhibits the formation of blood clots and/or enhances the integration of tissue structures around the string 72. Materials that may be used for the strings 72 include, for example, expanded PTFE (polytetrafluoroethylene), polyester fibers, or polypropylene. The chord 72 preferably comprises PTFE, a braided polymer such as polyester or monofilament polypropylene.

Returning now to FIG. 8, the connector 70 may also include a bottom connector 96 that is connected to the assembly 62 using the strings 72, one or more pegs 72, and/or a top connector 76.

The bottom connector 96 is preferably shaped to ensure that it traverses or is adjacent to or on the atrial surface of the anterior annulus of an atrial chamber valve 50, such as the mitral valve 52, to assist in connecting the ends 68 of the assembly 62 to help maintain the position of the device 60 relative to itself and the heart 10. It is also contemplated that a prosthetic valve and/or an annular plastic ring (annuloplasty) may be used to help secure and/or secure the bottom connector 96 to the heart 10. The bottom connector 96 has the shape of a portion of a prosthetic valve or a circular ring attached to the forward ring. The bottom connector 96 is typically comprised of a suitable rigid biocompatible material, similar to the assembly 62 described above, and preferably includes an apertured cover or outer surface to increase tissue integrity, such as a polyester fiber fabric.

As shown in fig. 8, the bottom pin 72 is preferably an elongated screw, pin, connector, or the like, and has a body portion 74 sized to allow the body portion 74 to pass through the hole 63. Head 73 of spike 72 is preferably larger in diameter than hole 93 in bottom connector 96 so that spike 72 cannot be removed. In addition, head 73 is preferably rounded so that it fits within counterbore 97 and can assist in rotation and/or swivel on a swivel axis. The body 74 has an externally threaded portion 75 that preferably extends along a portion of the body 74 opposite the head 73, or along the entire length.

Threaded portion 75 is preferably adapted with a fastener 98 having an internally threaded bore 99, as will be discussed later, to assist in attaching nail 72 to assembly 62. The pin 72 should be of sufficient length to assist in connecting the assembly 62 and the base connector 96, and the threaded portion 75 preferably extends outwardly from the counterbore 66 of the assembly 62 to secure a fastener (e.g., 98).

An end cap of the circular fastener 98 as shown in fig. 8 has an internally threaded bore 99, the threaded bore 99 being sized and shaped to mate with the externally threaded portion 75 whether entering or passing through the body.

The connector 70 also includes an elongated top peg 76 which is preferably bent into the shape shown in figure 8. The body 77 of the nail 76 preferably has externally threaded portions 79 adjacent the ends, each of which also cooperates with a fastener 98 having an internally threaded bore 99 to assist in the engagement of the nail 76 with the assembly 62. The entire body 77 should have external threads 79 that mate with a fastener 98 as described above. The top end peg 76 should be of sufficient length so that the threaded portion 79 extends outwardly from each of the enlarged openings 66 of the assembly 62 so that a fastener 98 is secured at each end.

Staples 72 and 76 and fasteners 98 are preferably comprised of a biocompatible material such as 3/6 stainless steel or CP titanium. In addition, the use of the same metallic material for the pegs 72 and 76, the fasteners 98, and the assembly 62 minimizes electrolyte erosion caused by different metallic materials being adjacent to or in contact with each other. In addition, the outer surfaces of staples 72 and 76 and fasteners 98 are preferably porous or have a porous protective coating or layer to enhance tissue integrity.

In another embodiment of the invention shown in fig. 9-10, a generally horseshoe-shaped or U-shaped strap-like device or belt 90, like device 60 described above, is used to assist in reorganizing and reconfiguring the heart 10. The strap 90 has at least two rigid portions 92, each similar to the assembly 62 described above. The strap 90 also includes a connector portion 94 that is generally only bendable in a plane tangential to the epicardial surface 34, and is shaped and positioned to be proximate to the epicardial surface 34 and to extend circumferentially around or across the apex 20 of the heart 10. Connector portion 94 should be sufficiently flexible to minimize the impedance of ventricular arterial kinks created during systole of heart 10, as shown in Figs. 11A and 11B, and to permit torsion of heart 10 during beating or contraction. When shown as a guard, the connector portion 94 may be of any shape so long as it is resilient and may be curved only in a plane tangential to the epicardial surface 34.

The strap 90 also preferably includes a bottom attachment 96 for assisting in attaching the strap 90 to the heart 10. In the illustrated embodiment, the bottom connector 96 is attached to the strap 90 at or near the end 91 of the strap 90 using the devices and techniques discussed above.

As shown in Figs. 12 and 13, the present invention may also use one or more accessory attachments 80 to hold the device 60 in position relative to itself and the heart 10, and more particularly to minimize lateral displacement of the heart 10 relative to the strap 90. The attachment aids 80 may be in the form of elongated spikes, or staples 82, shaped to penetrate the outer pericardial surface 34 into the heart tissue 32. The auxiliary links 80 may also be in the form of knobs 84 and chords 86. One end of the string 86 is secured or retained to the assembly 62 or the strap 90 and may extend inwardly into and through the heart tissue 32. A knob 84 is fixed or positioned immediately adjacent the other end of the chord 86 adjacent the endocardial surface 38. Knob 84 may be comprised of any biocompatible material, preferably a material that enhances tissue growth around knob 84 and minimizes the potential for thrombosis. It is further contemplated that other surgical attachment articles and techniques may be used with the present invention, such as screws, surgical staples, etc., to assist in securing and securing the device in the desired position.

In accordance with the teachings of the present invention, the device 60 should be shaped and positioned adjacent the heart 10, whereby, according to the Laplace theory of the cavity, the relationship is as follows:

cavity pressure = K^*(wall tension)/(radius of cavity),

here, K is a proportionality constant.

As an example of a representation according to the teachings of the present invention, the calculations are modeled in the example shown in fig. 3 and 5. Assuming a 100mm long axis for the left ventricle 12 of the heart 10, a 70mm equatorial or short axis for the chamber 12, an equatorial wall thickness "w" for the chamber of about 10mm, and a 60mm base diameter for the heart 10. A cross section of the left ventricle 12 is analyzed to illustrate the local sizing of the present invention.

In addition, the model assumes an unrestricted inner radius "R" of the heart 10₁"(of the cross-section or plane) is about 28.982 mm (see FIG. 3) and the outer radius of the heart 10 is about 38.406 mm. As known to those of ordinary skill in the art, the width "w" and radius "R₁"can be obtained directly from high resolution images, such as echocardiography, or preferably calculated by a hypothetical geometric model. The ratio of the systolic pressure to the chamber pressure of the left ventricle 12 of the device 60 varies between 1 and 2. This example further assumes that the ratio of the systolic pressure to the chamber pressure of the left ventricle 12 of the device 60 is limited to a maximum of about 1.5, which is disclosed in the following mathematical disclosureRepresented by the symbol K. At the same time, a changed radius "R" of the left ventricle 12 is required₂"is its initial radius R₁80% of (e), such as:

R₂=0．8^*R₁

R₂=0．8^*28．982mm

R₂=23．186mm

to calculate the radius of curvature "g" of the inner surface 64 of the component 62 in cross-section, the following equation may be used:

g=(w+R₂)÷(k-1)

f=(9．424mm+23．186mm)÷(1．5-1)

g=(32．61mm)÷0．5

g=65．22mm。

now that the radius of curvature "g" of the inner surface 64 has been calculated, the line segment g₁(in this plane, the line between the center of curvature of the component 62 and a point at the contact area between the inner surface 64 and the epicardial surface 34) and line segment g₂(line connecting the same center of curvature and the center of the inner surface 64 on the same plane) the angle "θ" between can be calculated by the following equation:

θ=(π／2)^*[R₂-R₁]÷(R₂+w+g)

θ=(π／2)^*[28．982mm-23．186mm]÷(28．982mm+9．424mm+65．22mm)

θ=(π／2)^*[5．796mm]÷(103．636mm)

θ = 0.09063 radians or 5.332 degrees

The distance over which the heart 10 is replaced can be calculated using the following formula to achieve the desired adjustment. If "e" is the distance from the absolute center of a reconstructed ventricle to the center of either component 62 on the plane, then:

e=(g+w+R₂)^*COSθ]-g

e=[(65．22mm+9．424mm+23．186mm)^*cos5．332°]-65．22mm

e=32．21mm

if so, twice e or (2 × e) is 64.42 mm, which is a more appropriate distance back from the inner surface 64.

Based on the calculations, the wall of the heart 10 needs to be replaced or moved inward a distance of about 6.2 mm from the unconstrained position to the desired reorganized or reconfigured position, where the wall tension can be adjusted as desired. The desired contact width of the inner surface 64 is also calculated according to equation 2 thetag, which in this example is about 11.68 mm.

When the device 60 is placed within the body (e.g., the chest) and around an existing natural heart 10, it is preferable to have a high resolution image, such as a standard echocardiogram, or other analysis of the heart 10, so that certain of the above-described analytic dimensions can be recorded and calculated. Since the present application includes only one set of mathematical calculations that optimize the present invention, it is anticipated that only a few axes, planes, locations along the lumen or dimensions along the long axis of the lumen need be obtained. Surgical calculations are preferably performed to optimize the shape and size of the device 60 as needed prior to surgery to minimize the time of the procedure.

Thoracic surgery, where the implantable device 60 requires opening of the heart, requires the implantable device 60. Accordingly, through the left atrial appendage of a beating heart 10, the intracardiac components are placed and positioned by the insertion of wall penetrating needles and or components. The patient is given sufficient clinical anesthesia and standard cardiac monitoring is performed, and then the chest cavity in which the heart 10 is located is opened via standard thoracic surgical procedures known to those of ordinary skill in the art.

Once the chest cavity is opened, if an open heart procedure is used in the present invention, blood circulation to the natural heart 10 will be bypassed so that the present invention may be inserted and/or inserted into the patient's body. Referring back now to fig. 2, the superior vena cava 22, the inferior vena cava 24, and the aorta 26 are cannulated. The circulatory system is connected to a cardiopulmonary bypass machine to maintain blood circulation and oxygenation during surgery. For example, the procedure specifically discussed is the insertion of the present invention 60 to reshape or reshape the left ventricle 12.

Turning now to fig. 4-6, a component 62 customized to anatomical dimensions and calculations is preferably positioned adjacent to or opposite the epicardial surface 34 at a predetermined location relative to each other and to the ventricular cavity (e.g., the left ventricle 12). The components 62 are freely positionable, 180 degrees relative to each other in FIG. 4 and 120 degrees relative to each other in FIG. 6. The assembly 62 may be temporarily attached to the heart 10 with temporary sutures or a suitable adhesive, such that the attachment member 70 may be attached and secured without removing the assembly 62.

Attachment element 70 is mounted or secured to assembly 62 such that portions of heart 10 are free to be forced inwardly. In one embodiment, if a surgical needle is used, the string 72 may be inserted through the aperture 63 in one of the members 62 and through the heart tissue 32, such that the string 72 may be passed through the left ventricle 13, into the heart tissue on the other side of the ventricular cavity (e.g., left ventricle 12), and finally through the corresponding aperture 63 in the oppositely mounted member 62. This may be repeated when multiple connectors 70 are required so that the assembly 62 can be freely installed and secured and is secure. The chord 72 may be cut or sized or made to a predetermined size and then attached to the assembly 62, such as by tying a suture knot, so that the chord 72 is taut between the assemblies 62, and as discussed in detail above, the assemblies 62 are thus positioned at a predetermined spacing (2 e) so that the heart 10 may be freely shaped or reformed.

Additionally, it is contemplated that the string 72 can be passed through the aperture 63, preferably near the end 62, and secured to strengthen the tissue structure surrounding the string 72. In one embodiment, the string 72 is passed through the aperture 63 and secured such that it extends adjacent the endocardial surface 38, or through the heart tissue 32 itself, to join the components 62.

In another embodiment utilizing a bottom connector 96, the bottom connector 96 is attached to the annulus of the coronary valve 52 by sutures and/or a suitable adhesive. Bottom peg 72 has a needle or other sharp device secured at an end opposite head 73. A suture may be placed between the needle and staple 72 to assist in passing staple 72 through heart tissue 32. The needle may be passed through the aperture 93 in the bottom connector 96, through the heart tissue (e.g., the free wall of the ventricle and/or the atrioventricular wall 42), and then through the aperture 63. The protruding threaded portion 75 is connected to a fastener 98, preferably threaded onto and connected to the nail 72. To enhance attachment and reduce the chance of the fastener 98 becoming loose, an auxiliary fastening device may be used as needed to assist in securing the assembly 62. The portion of the pin 72 beyond the catch 98 may be removed. Fastener 98 is preferably connected to peg 72 so that it is located in enlarged opening 66 and head 73 is preferably located in enlarged opening 97 to provide a ball and socket and/or pivot joint that allows some rotational movement of device 60 during contraction of heart 10.

Top peg 76 may also be part of connector 70, preferably having a needle or other sharp device attached to an end of body 77. The needle preferably passes through the reamer hole 66, the aperture 63, through the heart tissue 32 at or near the apex 20 of the heart 10, through the aperture 63 and the reamer hole 66 on the oppositely mounted assembly 62. A threaded connection 79 preferably projects into the assembly 62 from each of the enlarged openings 66. As described above, a fastener 98 with an internally threaded portion 99 is preferably screwed to each threaded connecting portion 79 to freely secure the assembly 62. The portion of the nail 76 that extends beyond the catch 98 may be removed. The fasteners 98 are preferably each located in their respective counterbored openings 66 to assist in providing a ball and socket and/or pivot joint as described above.

When the device 60 is used as a strap 90, the strap 90 and its rigid portion 92 are positioned near or opposite the epicardial surface 34 as the assembly 62 is secured or wrapped around the apical portion 20 of the heart 10 at the connector portion 94 to connect the rigid portions 92 together and to help maintain the strap 90 properly positioned near the heart 10 to provide the desired reshaping.

The bottom connector 96 as described above may be added to the annulus of the coronary valve 52. As described above, a connector 70, such as a string 72 or bottom peg 76, may be used to connect the remaining ends of the rigid portion 92.

If supplemental fasteners or attachment elements 80 are provided on or along the assembly 62 and/or strap 90, these supplemental fasteners or attachment elements will be inserted and attached to the heart 10.

Once the device 60 is positioned and secured, if cardiopulmonary bypass is also successfully stopped (if used), the thoracotomy is complete.

Another method of securing the device of the present invention comprises: the natural heart 10 is removed from the patient, all components of the present invention 60 are secured as described above, and the natural heart 10 is automatically transplanted back into the patient using heart removal and heart transplantation techniques known in the industry.

Further modifications of the device for activating a living heart described herein can be accomplished by appropriate modification of one of ordinary skill in the art in light of the above description of the preferred embodiment of the present invention, without departing from the scope of the present invention. For example, the present invention may be used with any one or a combination of different atrioventricular chambers of a living heart, and may also be used with embodiments of different structures to reshape the atrioventricular chambers. Some possible modifications such as these have been discussed and others will be apparent to those of ordinary skill in the art. The scope of the invention is, therefore, to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details, structures, and operations described in the specification and drawings.

Claims (32)

1. A fixation device for a heart having at least one cavity, the device comprising:

a set of shaping components positioned proximate to the epicardial surface; and

a connector for connecting said components;

characterised in that the devices are arranged spaced apart from each other to reconfigure a heart chamber having at least two flattened oval spheres with adjacent communicating portions as the heart chamber.

2. A fixation device for a heart having at least one cavity, the device comprising:

a set of shaping components positioned proximate to the epicardial surface; and

at least one connector extending through the entire cavity connecting the modules.

3. An immobilization device for an unconstrained heart having an outer wall and at least one cavity, said device comprising:

a set of shaping components positioned proximate to the epicardial surface; and

a connector for connecting said components;

wherein the components are secured in spaced relation to one another such that at least two portions of the outer wall are displaced from an unconstrained position to be centered.

4. The device of claim 3, wherein the member has a rectangular shape.

5. The device of claim 3, wherein said member includes an inner surface having an outwardly convex curvature.

6. The apparatus of claim 3 having first and second components, wherein said first and second components are positioned in a spaced relationship of 180 degrees from each other.

7. The device of claim 3, having a first component disposed proximate the front surface of the chamber and a second component disposed proximate the front surface of the chamber.

8. The apparatus of claim 3 including first, second and third components positioned in spaced relation 120 degrees from one another.

9. The device of claim 3, wherein the first component is formed adjacent to a front membrane portion of the cavity, the second component is formed adjacent to a rear membrane portion of the cavity, and the third component is formed adjacent to a rear side portion of the cavity.

10. The device of claim 3, wherein the device includes a liner adjacent the inner surface.

11. The device of claim 10, wherein the liner comprises a low durometer polymer.

12. The apparatus of claim 10, wherein the cushion comprises a cushion.

13. The apparatus of claim 12, wherein said cushion comprises a gel-filled cushion.

14. The apparatus of claim 12, wherein the cushion comprises a liquid-filled cushion.

15. The apparatus of claim 3, wherein the connector comprises a string.

16. The device of claim 15, wherein said connector comprises a polymeric knit saturated polyester fiber suture core having a polyester fiber sheath.

17. The device of claim 15, wherein the connector comprises a polymeric monofilament polypropylene suture.

18. The apparatus of claim 15, wherein the connector comprises extended polytetrafluoroethylene.

19. The device of claim 3, wherein the connector comprises a nail.

20. The apparatus of claim 19, wherein each of said components includes an aperture, and wherein said nail includes a threaded portion adjacent an end of said nail and a fastener received by said nail.

21. The device of claim 3, comprising at least one fixation device on the assembly having a shape suitable for insertion into the heart.

22. The device of claim 21, wherein the fixation device comprises a pin that passes through the heart wall.

23. The device of claim 21, wherein the fixation device comprises a knob disposed proximate an inner surface of the heart and a string connecting the connector and the knob.

24. The device of claim 3, wherein the connector comprises a strap shaped to extend around the cavity and connect the first component and the second component.

25. The device of claim 3, comprising a generally U-shaped band having a first rigid portion disposed proximate the anterior portion of the chamber, a second rigid portion disposed proximate the posterior portion of the chamber, and a flexible portion insertable into said first and second portions and having a shape disposed about the apical portion of the heart.

26. The device of claim 25, comprising a bottom connector having a shape adapted to be inserted between the first and second rigid portions of the strap.

27. The apparatus of claim 25, wherein the bottom connector is a ring secured to an atrial chamber valve.

28. A method of reducing wall tension in one of a heart chamber comprising the steps of:

attaching a fixation band to the heart provides the chamber of the heart as at least two adjacent portions of flattened oval spheres.

29. A method of reducing wall tension in one of an unrestricted heart chamber comprising the steps of:

a fixation device is attached to the heart having at least two components and a connector for energizing at least two portions of the chamber wall inwardly from an unconstrained position.

30. The method of claim 29, comprising the steps of: a fastener is arranged on the component and is inserted into the heart wall.

31. The method of claim 29, comprising the steps of: the connector is positioned in close proximity to the overlying tissue of the heart.

32. The method according to claim 9, comprising the steps of: the connector is secured to an atrial valve.