CARDIAC CHAMBER PROSTHESIS AND RELATED CARDIAC ASSISTANCE SYSTEM
20220265990 · 2022-08-25
Inventors
Cpc classification
A61M60/427
HUMAN NECESSITIES
A61M60/869
HUMAN NECESSITIES
A61M60/837
HUMAN NECESSITIES
A61M60/17
HUMAN NECESSITIES
A61M60/268
HUMAN NECESSITIES
A61M60/894
HUMAN NECESSITIES
International classification
A61M60/17
HUMAN NECESSITIES
A61M60/268
HUMAN NECESSITIES
Abstract
Cardiac chamber prosthesis configured to be implanted in a cardiac chamber (10; 20; 30; 40) comprising a native outlet valve (50; 60; 70; 80) and at least one inlet aperture (50; 70) selected from the group comprising a native inlet valve (50; 70) and one or more outlet mouths of venae cavae or pulmonary veins (120; 125; 130), wherein the cardiac chamber prosthesis comprises: an inner elastic membrane (250; 255; 260; 650; 750; 850), a reference support elastic membrane structure (200; 205, 225, 290A; 600; 700; 800) comprising or consisting of an outer elastic membrane (200; 205; 600; 700; 800) provided with a plurality of clips (210) configured to grip an inner wall (45) of the cardiac chamber (10; 20; 30; 40), wherein the elastic inner and outer membranes (250, 200; 255, 205; 260, 200; 650, 600; 750, 700; 850, 800) form an outlet border (285; 675; 785; 885) configured to surround and be sutured on the native outlet valve (50; 60; 70; 80) and at least one inlet border (275; 685; 775; 875A, 875B) configured to surround and be sutured on said at least one inlet aperture (50; 70), wherein the inner elastic membrane (250; 255; 260; 650; 750; 850) and the reference support elastic membrane structure (200; 205, 225, 290A; 600; 700; 800) are connected to each other by means of a plurality of primary variable connection elements (290; 290B), whereby the inner elastic membrane (250; 255; 260; 650; 750; 850) and the reference support elastic membrane structure (200; 205, 225, 290A; 600; 700; 800) delimit a primary interspace (230; 230B; 630; 730; 830) between them that is configured to receive a fluid with varying amount and/or pressure so as to dynamically modify a volume of the primary interspace (230; 2303; 630; 730; 830) and said elastically variable volume delimited by the inner surface (254; 654; 754; 854) of the inner elastic membrane (250; 255; 260; 650; 750; 850).
Claims
1. Cardiac chamber prosthesis configured to be implanted in a cardiac chamber of a patient selected from the group consisting of left ventricle, left atrium, right ventricle and right atrium, wherein the cardiac chamber comprises a native outlet valve and at least one inlet aperture selected from the group comprising a native inlet valve and one or more outlet mouths of venae cavae or pulmonary veins, wherein the prosthesis comprises: an inner elastic membrane, having an inner surface delimiting an elastically variable volume, provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, a reference support elastic membrane structure comprising or consisting of an outer elastic membrane provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, wherein the outer elastic membrane is further provided with a plurality of clips configured to grip an inner wall of the cardiac chamber, wherein the first borders of the first apertures of the inner and outer elastic membranes are integrally coupled to each other to form an outlet border configured to surround and be sutured on the native outlet valve, wherein the second borders of the second apertures the inner and outer elastic membranes are integrally coupled to each other to form at least one inlet border configured to surround and be sutured on the at least one inlet aperture, wherein the inner elastic membrane and the reference support elastic membrane structure are connected to each other by means of a plurality of primary variable connection elements, whereby the inner elastic membrane and the reference support elastic membrane structure delimit a primary interspace between them that is configured to receive a fluid with varying amount and/or pressure so as to dynamically modify a volume of the primary interspace and the elastically variable volume delimited by the inner surface of the inner elastic membrane.
2. Cardiac chamber prosthesis according to claim 1, wherein the outer elastic membrane has a coefficient of elasticity not greater, optionally lower, than a coefficient of elasticity of the inner elastic membrane.
3. Cardiac chamber prosthesis according to claim 1, wherein each one of the inner and outer elastic membranes has a variable coefficient of elasticity.
4. Cardiac chamber prosthesis according to claim 1, wherein the fluid is a liquid, optionally a haemocompatible solution, more optionally sterile saline solution, or a gas, optionally helium.
5. Cardiac chamber prosthesis according to claim 1, further comprising at least one artificial valve integrally coupled to the outlet border or the at least one inlet border.
6. Cardiac chamber prosthesis according to claim 1, wherein the primary variable connection elements are primary elastic ties each one of which has a coefficient of elasticity greater than a coefficient of elasticity of the outer elastic membrane and than a coefficient of elasticity of the inner elastic membrane.
7. Cardiac chamber prosthesis according to claim 1, configured to be contained inside a catheter.
8. Cardiac chamber prosthesis according to claim 1, wherein the outer elastic membrane and/or the inner elastic membrane comprise portions which are radiopaque.
9. Cardiac chamber prosthesis according to claim 1, wherein the primary interspace is configured to be in fluid communication with at least one variable volume elastic bag with which the prosthesis is provided or with an external pump.
10. Cardiac chamber prosthesis according to claim 1, wherein at least one of the inner elastic membrane and the outer elastic membrane has a discontinuous structure.
11. Cardiac chamber prosthesis according to claim 1, wherein the inner elastic membrane and the outer elastic membrane are each provided with a plurality of electrodes configured to electrically and/or electromagnetically polarise the inner elastic membrane and the outer elastic membrane, respectively, under control of an electronic processing unit connected to the electrodes through respective control cables.
12. Cardiac chamber prosthesis according to claim 1, wherein the reference support elastic membrane structure further comprises an intermediate elastic membrane that is interposed between the outer elastic membrane and the inner elastic membrane, wherein the intermediate elastic membrane is provided with a first aperture delimited by a respective first border, integrally coupled to the first borders of the first apertures of the inner and outer elastic membranes, and with at least one second aperture delimited by a respective second border, integrally coupled to the second borders of the second apertures of the inner and outer elastic membranes, wherein the intermediate elastic membrane and the outer elastic membrane are connected to each other by means of a plurality of secondary variable connection elements, wherein the secondary variable connection elements have coefficients of elasticity variable depending on the area of the intermediate elastic membrane to which they are connected, whereby the plurality of primary variable connection elements connect the inner elastic membrane and the intermediate elastic membrane to each other, whereby the outer elastic membrane and the intermediate elastic membrane delimit a secondary interspace between them that is configured to receive a fluid, optionally consisting in a liquid, more optionally a haemocompatible solution, more optionally sterile saline solution, or in a gas, optionally helium.
13. Cardiac chamber prosthesis according to claim 12, wherein the secondary interspace is configured to receive the fluid with varying amount and/or pressure, so as to dynamically modify a volume of the secondary interspace.
14. Cardiac chamber prosthesis according to claim 12, wherein the intermediate elastic membrane has a discontinuous structure.
15. Cardiac chamber prosthesis according to claim 12, wherein the intermediate elastic membrane is provided with a plurality of electrodes configured to electrically and/or electromagnetically polarise the intermediate elastic membrane under control of the electronic processing unit connected to the electrodes through respective one or more control cables.
16. Cardiac chamber prosthesis according to claim 1, wherein the cardiac chamber prosthesis is configured to be implanted: in a left ventricle, whereby the outlet border is an aortic border configured to surround and be sutured on a native aortic valve and the at least one inlet border consists of a mitral border configured to surround and be sutured on a native mitral valve, or in a left atrium, whereby the outlet border is a mitral border configured to surround and be sutured on a native mitral valve and the at least one inlet border consists of one or more borders of pulmonary veins configured to surround and be sutured in correspondence of respective one or more outlet mouths of pulmonary veins, or in a right ventricle, whereby the outlet border is a pulmonary valve border configured to surround and be sutured on a native pulmonary valve and the at least one inlet border consists of a tricuspid valve border configured to surround and be sutured on a native tricuspid valve, or in a right atrium, whereby the outlet border is a tricuspid valve border configured to surround and be sutured on a native tricuspid valve and the at least one inlet border consists of one or more borders of venae cavae configured to surround and be sutured in correspondence of respective one or more outlet mouths of venae cavae.
17. Assembly of cardiac chamber prostheses comprising two to four cardiac chamber prostheses, wherein the two to four cardiac chamber prostheses are configured to be implanted in respective two or more cardiac chambers of a patient selected from the group consisting of left ventricle, left atrium, right ventricle and right atrium, wherein each of the respective two to four cardiac chambers comprises a native outlet valve and at least one inlet aperture selected from the group comprising a native inlet valve and one or more outlet mouths of venae cavae or pulmonary veins, wherein each of the two to four cardiac chamber prostheses comprises: an inner elastic membrane, having an inner surface delimiting an elastically variable volume, provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, a reference support elastic membrane structure comprising or consisting of an outer elastic membrane provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, wherein the outer elastic membrane is further provided with a plurality of clips configured to grip an inner wall of the cardiac chamber, wherein the first borders of the first apertures of the inner and outer elastic membranes are integrally coupled to each other to form an outlet border configured to surround and be sutured on the native outlet valve, wherein the second borders of the second apertures of the inner and outer elastic membranes are integrally coupled to each other to form at least one inlet border configured to surround and be sutured on the at least one inlet aperture, wherein the inner elastic membrane and the reference support elastic membrane structure are connected to each other by means of a plurality of primary variable connection elements, whereby the inner elastic membrane and the reference support elastic membrane structure delimit a primary interspace between them that is configured to receive a fluid with varying amount and/or pressure so as to dynamically modify a volume of the primary interspace and the elastically variable volume delimited by the inner surface of the inner elastic membrane.
18. Assembly of cardiac chamber prostheses according to claim 17, wherein the cardiac chamber prostheses comprise or consist of two cardiac chamber prostheses which are associated to each other and are configured to be implanted in a left ventricle and in a left atrium, or in a right ventricle and in a right atrium, in each one of the associated two cardiac chamber prostheses the inner elastic membrane and the outer elastic membrane are each provided with a plurality of electrodes configured to electrically and/or electromagnetically polarise the inner elastic membrane and the outer elastic membrane, respectively, under control of an electronic processing unit connected to the electrodes through respective control cables, wherein the primary interspaces of the associated two cardiac chamber prostheses are in fluid communication with each other through a communication duct, whereby the volume of the primary interspace of one of the two associated cardiac chamber prostheses is configured to increase when the volume of the primary interspace of the other one of the two associated cardiac chamber prostheses decreases, and vice versa, through a displacement of fluid between the primary interspaces of the two associated cardiac chamber prostheses.
19. Cardiac assistance system comprising: a cardiac chamber prosthesis configured to be implanted in a cardiac chamber of a patient selected from the group consisting of left ventricle, left atrium, right ventricle and right atrium, wherein the cardiac chamber comprises a native outlet valve and at least one inlet aperture selected from the group comprising a native inlet valve and one or more outlet mouths of venae cavae or pulmonary veins, wherein the prosthesis comprises: an inner elastic membrane, having an inner surface delimiting and elastically variable volume, provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, a reference support elastic membrane structure comprising or consisting of an outer elastic membrane provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, wherein the outer elastic membrane is further provided with a plurality of clips configured to grip an inner wall of the cardiac chamber, wherein the first borders of the first apertures of the inner and outer elastic membranes are integrally coupled to each other to form an outlet border configured to surround and be sutured on the native outlet valve, wherein the second borders of the second apertures of the inner and outer elastic membranes are integrally coupled to each other to form at least one inlet border configured to surround and be sutured on the at least one inlet aperture, wherein the inner elastic membrane and the reference support elastic membrane structure are connected to each other by means of a plurality of primary variable connection elements, whereby the inner elastic membrane and the reference support elastic membrane structure delimit a primary interspace between them that is configured to receive a fluid with varying amount and/or pressure so as to dynamically modify a volume of the primary interspace and the elastically variable volume delimited by the inner surface of the inner elastic membrane, and at least one pump and/or an electronic processing unit configured to control an amount and/or a pressure of the fluid received in the primary interspace of the cardiac chamber prosthesis so as to dynamically modify the volume of the primary interspace of the cardiac chamber prosthesis.
20. Cardiac assistance system comprising: an assembly of cardiac chamber prostheses, comprising two to four cardiac chamber prostheses, wherein the two to four cardiac chamber prostheses are configured to be implanted in respective two or more cardiac chambers of a patient selected from the group consisting of left ventricle, left atrium, right ventricle and right atrium, wherein each of the respective two to four cardiac chambers comprises a native outlet valve and at least one inlet aperture selected from the group comprising a native inlet valve and one or more outlet mouths of venae cavae or pulmonary veins, wherein each of the two to four cardiac chamber prostheses comprises: an inner elastic membrane, having an inner surface delimiting an elastically variable volume, provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, a reference support elastic membrane structure comprising or consisting of an outer elastic membrane provided with a first aperture delimited by a respective first border and with at least one second aperture delimited by a respective second border, wherein the outer elastic membrane is further provided with a plurality of clips configured to grip an inner wall of the cardiac chamber, wherein the first borders of the first apertures of the inner and outer elastic membranes are integrally coupled to each other to form an outlet border configured to surround and be sutured on the native outlet valve, wherein the second borders of the second apertures of the inner and outer elastic membranes are integrally coupled to each other to form at least one inlet border configured to surround and be sutured on the at least one inlet aperture, wherein the inner elastic membrane and the reference support elastic membrane structure are connected to each other by means of a plurality of primary variable connection elements, whereby the inner elastic membrane and the reference support elastic membrane structure delimit a primary interspace between them that is configured to receive a fluid with varying amount and/or pressure so as to dynamically modify a volume of the primary interspace and the elastically variable volume delimited by the inner surface of the inner elastic membrane, and at least one pump and/or an electronic processing unit configured to control an amount and/or a pressure of the fluid received in the primary interspace of the cardiac chamber prosthesis or of the cardiac chamber prostheses of the assembly of cardiac chamber prostheses so as to dynamically modify the volume of the primary interspace of the cardiac chamber prosthesis or of the cardiac chamber prostheses of the assembly of cardiac chamber prostheses.
21. Cardiac chamber prosthesis according to claim 3, wherein each one of the inner and outer elastic membranes comprises two or more areas having respective coefficients of elasticity.
22. Cardiac chamber prosthesis according to claim 6, wherein the primary elastic ties have coefficients of elasticity variable depending on the area of the inner elastic membrane to which they are connected.
23. Cardiac chamber prosthesis according to claim 10, wherein the discontinuous structure is a honeycomb discontinuous structure formed by a plurality of elastic plates, optionally hexagonal ones, connected to each other along elastic junction lines.
24. Cardiac chamber prosthesis according to claim 23, wherein the elastic junction lines have a coefficient of elasticity greater than a coefficient of elasticity of the elastic plates.
25. Cardiac chamber prosthesis according to claim 10, wherein the discontinuous structure is formed by a plurality of elastic polygonal plates, optionally with pentagonal and/or hexagonal shape, connected to each other along elastic junction lines.
26. Cardiac chamber prosthesis according to claim 25, wherein the elastic junction lines have a coefficient of elasticity greater than a coefficient of elasticity of the elastic polygonal plates.
27. Cardiac chamber prosthesis according to claim 12, wherein the intermediate elastic membrane has a coefficient of elasticity not greater, optionally lower, than a coefficient of elasticity of the outer elastic membrane and than a coefficient of elasticity of the inner elastic membrane.
28. Cardiac chamber prosthesis according to claim 12, wherein the plurality of secondary variable connection elements consist of secondary elastic ties.
29. Cardiac chamber prosthesis according to claim 28, wherein each one of the secondary elastic ties has a coefficient of elasticity greater than the coefficient of elasticity of the outer elastic membrane and than the coefficient of elasticity of the intermediate elastic membrane.
30. Cardiac chamber prosthesis according to claim 13, wherein the secondary interspace is configured to be in fluid communication with at least one variable volume elastic bag with which the prosthesis is provided or with an external pump.
31. Cardiac chamber prosthesis according to claim 14, wherein the discontinuous structure is a honeycomb discontinuous structure formed by a plurality of elastic plates, optionally hexagonal ones, connected to each other along elastic junction lines.
32. Cardiac chamber prosthesis according to claim 31, wherein the elastic junction lines have a coefficient of elasticity greater than a coefficient of elasticity of the elastic plates.
33. Cardiac chamber prosthesis according to claim 14, wherein the discontinuous structure is formed by a plurality of elastic polygonal plates, optionally with pentagonal and/or hexagonal shape, connected to each other along elastic junction lines.
34. Cardiac chamber prosthesis according to claim 33, wherein the elastic junction lines have a coefficient of elasticity greater than a coefficient of elasticity of the elastic polygonal plates.
Description
[0056] The present invention will be now described, by way of illustration and not by way of limitation, according to its preferred embodiments, by particularly referring to the Figures of the annexed drawings, in which:
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[0069] In the Figures identical reference numbers will be used for alike elements.
[0070] With reference to
[0071] The outer elastic membrane 200 and the inner elastic membrane 250 are elastically connected to each other by means of a plurality of elastic ties 290, each having two ends integrally coupled to the inner surface 204 of the outer elastic membrane 200 and to the outer surface 252 of the inner elastic membrane 250, respectively. Each of the elastic ties 290 is configured to be elastically elongated, when subjected to a stress that causes its ends to move away from each other, starting from a rest configuration. The outer surface 202 of the outer elastic membrane 200 is provided with a plurality of conventional hook fasteners 210 (also known as clips), similar to those used to secure the left ventricular volume reduction prostheses to the inner wall 45 of the left ventricle, which are configured to grip the inner wall 45 of the left ventricle by sticking into the tissue of the left ventricle, and allowing the outer elastic membrane 200 to be stably implanted there, as shown in
[0072] Both the outer elastic membrane 200 and the inner elastic membrane 250 have each a morphology that approximates the one of the inner wall 45 of a left ventricle (in which the prosthesis is intended to be implanted), whereby they substantially comprise three areas: a base where the first and second apertures are arranged, a ventricular apex and an intermediate wall that joins the base and the ventricular apex, thereby the intermediate wall is arranged in an intermediate position between the base and the ventricular apex. This allows the outer elastic membrane 200 to fit like an inner glove to the inner wall of the ventricle to which it is configured to grip through the clips 210.
[0073] In this regard, the left ventricle prosthesis, namely the outer elastic membrane 200 and its inner elastic membrane 250, can be made in various sizes to adapt to the specific volumes of the left ventricle of different patients, which are linked to the patient's body surface (BSA—Body Surface Area).
[0074] Thanks to such shape of the outer and inner elastic membranes 200 and 250, the prosthesis is configured to be implanted inside the left ventricle by adapting to its tissue, to the inner wall 45 of which it is configured to grip through the clips 210. Optionally, the shape of the lateral surface of the two outer and inner elastic membranes 200 and 250 can include two notches (not shown in the Figures), without clips, configured to receive the anterior and posterior papillary muscles and the tendinous cords of the left ventricle (also not shown in the Figures) connected to the mitral valve 70 in order not to make the prosthesis interfere with the papillary muscles and tendinous cords themselves.
[0075] In any case, the two outer and inner elastic membranes 200 and 250 must not necessarily have a morphology exactly conforming to the one of the inner wall 45 of a left ventricle (in which the prosthesis is intended to be implanted), since their elasticity allows to compensate any morphological differences; in particular, the elasticity of the outer elastic membrane 200 allows it to follow the morphology of the inner wall 45 of the left ventricle which it grip through the clips 210.
[0076] The mitral border 275 is configured to surround and be sutured on the native mitral valve 70 and the aortic border 285 is configured to surround and be sutured on the native aortic valve 80. In particular, the mitral border 275 operates as inlet border, the native mitral valve 70 operates as native inlet valve of which the at least one inlet opening of the cardiac chamber consists, the aortic border 285 operates as outlet border, and the native aortic valve 80 operates as native outlet valve.
[0077] The outer and inner elastic membranes 200 and 250 and the ties 290 are made of biocompatible elastic materials, optionally biocompatible elastic polymeric materials, more optionally polytetrafluoroethylene (also known as ePTFE).
[0078] The clips 210 are made of biocompatible metal material, optionally a shape memory alloy, more optionally a nickel titanium shape memory alloy (also known as NITINOL).
[0079] The outer and inner elastic membranes 200 and 250, elastically connected to each other by means of the plurality of elastic ties 290, delimit a closed interspace 230 between them having a volume configured to be elastically variable, as it will be described in detail later. In particular, the reference support elastic membrane structure consists of the outer elastic membrane 200, the interspace 230 operates as primary interspace and the plurality of elastic ties 290 operates as plurality of primary variable connection elements.
[0080] Advantageously, the outer elastic membrane 200 has a coefficient of elasticity not greater (i.e. lower than or equal to), optionally lower (i.e. it is less elastic), than the coefficient of elasticity of the inner elastic membrane 250. Also, in order to better simulate the physiological elastic behaviour of the left ventricle, the coefficient of elasticity of the inner elastic membrane 250 is optionally variable according to the area thereof, as it will be described in greater detail later.
[0081] Advantageously, the elastic ties 290 have a coefficient of elasticity greater than the one of the outer and inner elastic membranes 200 and 250. Still in order to better simulate the physiological elastic behaviour of the left ventricle, the coefficient of elasticity of the elastic ties 290 is optionally variable according to the area of the inner elastic membrane 250 to which they are connected with one end thereof, as it will be described in greater detail later.
[0082] The left ventricle prosthesis shown in
[0083] After insertion into the left ventricle, the prosthesis is expanded and the clips 210 with which the outer surface 202 of the outer elastic membrane 200 is provided grip the inner wall 45 of the left ventricle so as to stably position the prosthesis in the left ventricle itself. The mitral border 275, that is positioned so as to surround the mitral valve 70, is sutured in proximity of the mitral valve 70 itself; similarly, the aortic border 285, that is positioned so as to surround the aortic valve 80, is sutured in proximity of the aortic valve 80 itself.
[0084] Alternatively, the left ventricular prosthesis shown in
[0085] Advantageously, the left ventricle prosthesis according to the invention comprises portions, e.g. in the outer elastic membrane 200 and/or the inner elastic membrane 250, which are radiopaque, thereby they are visible by radioscopy, to assist the surgeon during the placement of the prosthesis in the left ventricle (for instance, the mitral border 275 and the aortic border 285 can be radiopaque).
[0086] The interspace 230 delimited by the outer elastic membrane 200 and the inner elastic membrane 250 is configured to receive a fluid, in particular a liquid, such as a haemocompatible solution, for instance sterile saline solution, or a gas, for instance helium, with varying amount and/or pressure to dynamically modify the volume of the interspace 230 itself and, thus, to modify the elastically variable volume delimited by the inner surface 254 of the inner elastic membrane 250.
[0087] To this end, the interspace 230 is accessible through (at least) one access hole arranged on the outer elastic membrane 200, on which hole, after implantation of the prosthesis in the left ventricle, a duct 330 is sutured, wherein the duct 330 connects the interspace 230 to an external (hydraulic or pneumatic) pump 340A. Optionally, the borders of this (at least one) access hole are made of radiopaque material, to allow their easy identification for positioning the duct 330; during insertion of the prosthesis into the left ventricle, this (at least one) access hole is closed to prevent biological material from entering the interspace 230. Said (at least one) hole can be arranged in any position of the outer elastic membrane 200 and the duct 330 can consequently cross a corresponding area of the myocardium (possibly also passing through the aorta 100). Advantageously, the prosthesis can be provided with a plurality of sealed access holes (or simply with borders delimiting an area of the outer elastic membrane 200 that can be removed to make an access hole, on which borders the duct 330 can be sutured), and the plurality of sealed access holes can be distributed on the outer elastic membrane 200: the surgeon can select the access hole on which the duct 330 is to be sutured on the basis of the position on the outer elastic membrane 200 which corresponds to an adequate area of the myocardium, and can open the selected access hole (or remove the area of the outer elastic membrane 200 delimited by the selected border to make the access hole), then suturing the duct 330 on its border. Alternatively, the surgeon can make the hole access in any position on the outer elastic membrane 200 (that corresponds to an adequate area of the myocardium) by removing an area of the outer elastic membrane 200 and then suturing the duct 330 on the border of the hole thus created.
[0088] To better understand the invention, the main operating modes of the left ventricle prosthesis shown in
[0089] Making reference to
[0090] At the end of the atrial systole, the blood stops flowing from the left atrium 20 inside the inner elastic membrane 250, the mitral valve 70 closes and the aortic valve 80 opens, thus starting a new cardiac cycle.
[0091] The prosthesis allows to obtain an efficient emptying of the inside of the inner elastic membrane 250 during ventricular systole, thanks to the introduction of fluid into the interspace 230, and a better emptying of the left atrium 20 and an efficient filling of the inside of the inner elastic membrane 250 during atrial systole, thanks to the removal of fluid from the interspace 230.
[0092] In other words, the outer elastic membrane 200, integral with the inner wall 45 of the left ventricle, operates as a pivot for the inner elastic membrane 250 assisting its displacements towards the centre of the left ventricle and in the opposite direction towards the inner wall 45 of the left ventricle, allowing a reliable, rapid and efficient variation of the volume of the interspace 230. For this reason, the outer elastic membrane 200 advantageously has a lower coefficient of elasticity than the one of the inner elastic membrane 250, so as to be more rigid than the latter and have limited expansions.
[0093] As stated, in order to better simulate the physiological elastic behaviour of the left ventricle, the coefficient of elasticity of the inner elastic membrane 250 is optionally variable depending on the area. In fact, the ventricular apex has greater displacements than the intermediate areas and, even more, with respect to the areas of the mitral valve 70 and the aortic valve 80, which are the most rigid since the flow lines from the first to the second are not long. Consequently, optionally the base of the inner elastic membrane 250 has a lower coefficient of elasticity than the one of the intermediate wall of the inner elastic membrane 250, and the coefficient of elasticity of the intermediate wall of the inner elastic membrane 250 is lower than the one of the ventricular apex of the inner elastic membrane 250 (that has the maximum coefficient of elasticity). This permits to avoid creating potential flow turbulence and energy losses. Possibly, the elastic coefficient of the inner elastic membrane 250 can also vary in a continuous way (gradually increasing) going from the base to the ventricular apex of the inner elastic membrane 250.
[0094] Still in order to better simulate the physiological elastic behaviour of the left ventricle, the coefficient of elasticity of the elastic ties 290 is optionally variable according to the area of the inner elastic membrane 250 to which they are connected with one of their ends, namely: the elastic ties 290 connected to the base of the inner elastic membrane 250 have a coefficient of elasticity lower than the one of the elastic ties 290 connected to the intermediate wall of the inner elastic membrane 250, and the coefficient of elasticity of the elastic ties 290 connected to the intermediate wall of the inner elastic membrane 250 is lower than the one of the elastic ties 290 connected to the ventricular apex of the inner elastic membrane 250 (which have the maximum coefficient of elasticity). Possibly, the elastic coefficient of the elastic ties 290 can also vary in a continuous way (progressively increasing) going from the base to the ventricular apex of the inner elastic membrane 250.
[0095] As shown in
[0096] The cardiac assistance system comprising the left ventricle prosthesis and the pump 340A (controlled by the electronic processing unit) can be used as a semi-permanent bridge, i.e. as a transient support system until a new cardiac organ is available for transplantation, or as a permanent prosthetic system as an alternative to the replacement of the entire cardiac organ.
[0097] A significant advantage offered by the prosthesis according to the invention over the prior art solutions is that the patient continues to have the native cardiac organ, despite its reduced and conditioned functionality. Also thanks to the less invasive nature of the prosthesis according to the invention, this allows to maintain or restore a correct functionality of the other cardiac chambers which could begin to have dysfunctions caused by left ventricular dysfunction. By way of example, a left ventricular dysfunction over time can lead to degeneration and hence also to a pathology of the left atrium; even correcting the left ventricle alone, it is possible to re-establish an adequate work of the left atrium, as well as of the right ventricle and, consequently, of the right atrium. In this way, the prosthesis according to the invention allows to recover the rest of the organ that is not yet totally compromised.
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[0099] Other embodiments of the prosthesis according to the invention can have the inner elastic membrane that has a discontinuous structure different from that shown in
[0100] Advantageously, the elastic ties 290 connecting the inner surface 204 of the outer elastic membrane 200 to the outer surface of the inner elastic membrane 260 are fixed to apices (i.e. vertices) of elastic plates 265 (coinciding with ends of elastic junction lines 267) forming the honeycomb discontinuous structure (or, more generally, to apices of elastic polygonal plates forming the discontinuous structure).
[0101] Optionally, the coefficient of elasticity of the elastic junction lines 267 is greater than the one of the elastic plates 265; in this case, the minimum volume delimited by the inner elastic membrane 260 is always greater than zero, increasing the reliability and efficiency of the operation of the prosthesis.
[0102] Further embodiments of the prosthesis according to the invention may have the outer elastic membrane which has a discontinuous structure formed by a plurality of elastic plates connected to each other, wherein such discontinuous structure can have a honeycomb conformation, e.g. with hexagonal plates, or a polygonal plates one, such as with pentagons and/or hexagons. Advantageously, the elastic ties connecting the inner surface of the outer elastic membrane to the outer surface of the inner elastic membrane are fixed to apices of elastic plates (coinciding with ends of elastic junction lines) forming the discontinuous structure of the outer elastic membrane. Also, the outer elastic membrane can be possibly perforated. The embodiments with an outer elastic membrane having a discontinuous structure can be provided with an inner elastic membrane having either a continuous or a discontinuous structure.
[0103] With reference to
[0104] The variation in the volume of the interspace 230 is controlled by the electrical and/or electromagnetic polarity of the outer and inner elastic membranes 205 and 255. During the ventricular systole (shown in
[0105] In this regard, the interspace 230 can be filled with a liquid (e.g. haemocompatible solution) and is in fluid communication with at least one variable volume elastic bag (not shown in the Figures), operating as a liquid reservoir, that can be positioned inside the myocardium (for instance in proximity to the aortic valve 80 and/or in proximity to the mitral valve 70) or outside the myocardium; during atrial systole, the liquid is displaced from the interspace 230 into the elastic bag (which increases its volume), and during ventricular systole the liquid is displaced from the elastic bag (which decreases its volume) into the interspace 230. Alternatively to, or in combination with, the liquid, the interspace 230 can be filled with a gas (e.g. helium) that, since it is compressible, can vary its pressure from a high value, during the atrial systole, to a low value, during the ventricular systole, without necessarily requiring that the interspace 230 be in fluid communication with a variable volume elastic bag (that, in this case, is thus optional).
[0106] The electronic processing unit 345A can control the electric and/or electromagnetic polarity of each one of the outer and inner elastic membranes 205 and 255 in a way that varies in time and in amplitude in function of the specific area of the (outer or inner) elastic membrane (205 or 255) under consideration. In particular, the electronic processing unit 345A can control the electrodes of the outer elastic membrane 205 with the same control signal (also variable over time), or by considering the electrodes subdivided into distinct groups (for instance, a base group comprising one or more electrodes arranged in the base of the outer elastic membrane 205, an intermediate wall group comprising one or more electrodes arranged in the intermediate wall of the outer elastic membrane 205, and a ventricular apex group comprising one or more electrodes arranged in the ventricular apex of the outer elastic membrane 205) each of which is controlled by a respective control signal (also variable over time), or by sending a corresponding control signal (also variable over time) to each one of the electrodes (wherein possibly two or more electrodes can receive corresponding control signals identical to each other). Similarly, the electronic processing unit 345A can also control the electrodes of the inner elastic membrane 255 in similar modes, i.e. with the same control signal (also variable over time), or with respective control signals (also variable over time) for distinct groups into which the electrodes are subdivided, or with corresponding control signals (also variable over time) for each one of the electrodes. In this regard, the electrode control mode of the outer elastic membrane 205 can be the same as or different from the electrode control mode of the inner elastic membrane 255.
[0107] The power supply of the electronic processing unit 345A that controls the operation of the prosthesis occurs through, optionally rechargeable, batteries (or accumulators) and can be housed in an external box (or even a backpack) carried by a patient (in a similar way to what shown in
[0108] The cardiac assistance system including the left ventricle prosthesis of
[0109] The left ventricle prosthesis shown in
[0110] In particular, the artificial aortic valve 530 integrally coupled to the aortic border 285 delimiting the aortic aperture 280 of the prosthesis according to the invention has a better positioning and greater stability than what obtainable with the prior art artificial aortic valves. In particular, the operation of the artificial aortic valve 530 could also be controlled by specific electrodes distributed on the components of the valve itself which are configured to cause the valve to open and close through an electrical and/or electromagnetic polarisation of such components, wherein the electrodes are in turn controlled by the electronic processing unit 345A. Also, the artificial aortic valve 530 avoids the problems of residual regurgitation after implantation which can occur with a conventional percutaneous artificial aortic valve implant, also known as TAVI (Trans Aortic Valve Implantation).
[0111] Alternatively or in combination with the artificial aortic valve 530, other embodiments of the prosthesis according to the invention can be provided with an artificial mitral valve. Also the embodiments of the prosthesis according to the invention in which the volume delimited by the interspace 230 is controlled by a pump that introduces or sucks a fluid into or from it can be provided with artificial valves.
[0112] It must be noted that other embodiments of the prosthesis according to the invention can use both a hydraulic or pneumatic control, as shown in
[0113] With reference to
[0114] The left ventricle prosthesis shown in
[0115] Similarly to the outer and inner elastic membranes 205 and 255, even the intermediate elastic membrane 225 is provided with a plurality of, optionally electrically insulated, electrodes configured to electrically and/or electromagnetically polarise the intermediate elastic membrane 225 itself, under control of an electronic processing unit 345B, that also controls the electrical and/or electromagnetic polarisation of the outer and inner elastic membranes 205 and 255 and that is connected to the electrodes of the outer, intermediate and inner elastic membranes 205, 225 and 255 by means of respective control cables 206, 226 and 256.
[0116] The intermediate elastic membrane 225 is elastically connected to the outer elastic membrane 205 and to the inner elastic membrane 255 by means of a plurality of outer elastic ties 290A and a plurality of inner elastic ties 290B, respectively. Each one of the outer elastic ties 290A has two ends integrally coupled to the inner surface of the outer elastic membrane 205 and to the outer surface (i.e. the surface facing the outer elastic membrane 205) of the intermediate elastic membrane 225, respectively; similarly, each one of the inner elastic ties 290B has two ends integrally coupled to the outer surface of the inner elastic membrane 255 and to the inner surface (i.e. the surface facing the inner elastic membrane 205) of the intermediate elastic membrane 225, respectively. Each one of the inner elastic ties 290B is configured to be elastically elongated, when subjected to a stress that causes its ends to move away from each other, starting from a rest configuration; advantageously, also each one of the outer elastic ties 290A is configured to be elastically elongated, when subjected to a stress that causes its ends to move away from each other, starting from a rest configuration. Optionally, the coefficient of elasticity of the outer elastic ties 290A is greater than the coefficient of elasticity of the intermediate elastic membrane 225 and the coefficient of elasticity of the outer elastic membrane 205; more optionally, the coefficient of elasticity of the outer elastic ties 290A varies in function of the area of the intermediate elastic membrane 225 to which they are connected.
[0117] As stated, the outer and inner elastic membranes 205 and 255 are like those of the embodiment shown in
[0118] Also the intermediate elastic membrane 225, as the outer and inner elastic membranes 205 and 255, advantageously has a morphology which approximates the one of the inner wall 45 of a left ventricle (in which the prosthesis is intended to be implanted), optionally comprising two notches configured to receive the anterior and posterior papillary muscles and the tendinous cords of the left ventricle connected to the mitral valve 70, and can be made in various sizes to adapt to the specific volumes of the left ventricle of different patients, which are related to the patient's BSA. In any case, similarly to the two outer and inner elastic membranes 205 and 255, even the intermediate elastic membrane 225 must not necessarily have a morphology exactly conforming to the one of the inner wall 45 of a left ventricle (in which the prosthesis is intended to be implanted), since its elasticity allows to compensate for any morphological differences.
[0119] Moreover, the intermediate elastic membrane 225, as well as the outer and inner elastic membranes 205 and 255, as well as the outer elastic ties 290A and the inner elastic ties 290B are made of biocompatible elastic materials, optionally biocompatible elastic polymeric materials, more optionally polytetrafluoroethylene (also known such as ePTFE).
[0120] The outer and intermediate elastic membranes 205 and 225, elastically connected to each other by means of the plurality of outer elastic ties 290A, delimit a closed outer interspace 230A between them having a volume configured to be elastically variable (even if this is not an essential feature for the invention). The intermediate and inner elastic membranes 225 and 255, elastically connected to each other by means of the plurality of inner elastic ties 290B, delimit a closed inner interspace 230B between them having a volume configured to be elastically variable, as t will be described in detail later.
[0121] In particular, the reference support elastic membrane structure comprises the outer elastic membrane 205, the intermediate elastic membrane 225 and the plurality of outer elastic ties 290A. Also, the inner interspace 230B operates as a primary interspace, the outer interspace 230A operates as a secondary interspace, the plurality of inner elastic ties 290B operates as a plurality of primary variable connection elements, and the plurality of outer elastic ties 290A operates as a plurality of secondary variable connection elements.
[0122] The intermediate elastic membrane 225 can have both a continuous structure and a discontinuous structure formed by a plurality of elastic plates connected to each other, wherein such discontinuous structure can have a honeycomb conformation, e.g. with hexagonal plates, or a polygonal plate one, such as with pentagons and/or hexagons. Advantageously, the elastic ties connecting the inner surface of the outer elastic membrane to the outer surface of the intermediate elastic membrane and the elastic ties connecting the outer surface of the inner elastic membrane to the inner surface of the intermediate elastic membrane are fixed to apices of elastic plates (coinciding with ends of elastic junction lines) forming the discontinuous structure of the intermediate elastic membrane. The embodiments with an intermediate elastic membrane having a discontinuous structure can be provided with an inner elastic membrane having either a continuous or a discontinuous structure and an outer elastic membrane having either a continuous or a discontinuous structure.
[0123] Also in the fourth embodiment of the prosthesis shown in
[0124] In this regard, the electronic processing unit 345B controls the electrical and/or electromagnetic polarisation of all and each of the outer, intermediate and inner elastic membranes 205, 225 and 255 so that the intermediate elastic membrane 225 assumes a substantially static (i.e. constant) position that internally defines the physiological ventricular telediastolic volume of the patient, and so that the inner elastic membrane 255 moves with respect to the intermediate elastic membrane 225, cyclically varying the volume of the inner interspace 230B. In particular, during the atrial systole (shown in
[0125] In a first mode of operation, the electronic processing unit 345B keeps the polarisation of the intermediate elastic membrane 225 constant and dynamically varies the polarisation of the outer elastic membrane 205 and of the inner elastic membrane 255. In particular, during a cardiac cycle, the electronic processing unit 345B also dynamically varies the polarisation of the outer elastic membrane 205 to prevent the polarity changes of the inner elastic membrane 255 from causing a displacement of the intermediate elastic membrane 225 with respect to the substantially static (i.e. constant) reference position that internally defines the physiological ventricular telediastolic volume of the patient. In other words, in such first mode of operation, the volume of the outer interspace 230A remains substantially constant.
[0126] Other modes of operation of the prosthesis shown in
[0127] Furthermore, further modes of operation of the prosthesis shown in
[0128] Similarly to the interspace 230 of the prosthesis of
[0129] In the modes of operation wherein the volume of the outer interspace 230A remains substantially constant, this can be filled with a predetermined amount of liquid (e.g. haemocompatible solution) or gas (e.g. helium).
[0130] In the other modes of operation of the prosthesis shown in
[0131] A fifth embodiment of the prosthesis according to the invention still intended for the left ventricle differs from that shown in
[0132] It must noted that other embodiments of the prosthesis according to the invention intended for the left ventricle and having the outer, intermediate and inner elastic membranes 205, 225 and 255 can use both a hydraulic or pneumatic control and an electric and/or electromagnetic control, wherein the two types of controls cooperate in the variation of the volume delimited by the inner interspace 230B (and possibly of the volume delimited by the outer interspace 230A).
[0133] Further embodiments of the prosthesis according to the invention are intended for one of the other three cardiac chambers, i.e. left atrium 20, right ventricle 30 and right atrium 10, and are similar to what illustrated for the prostheses shown in
[0140] In particular, the coefficient of elasticity of the elastic membranes of the prostheses can be different also in function of the specific cardiac chamber for which each prosthesis is intended.
[0141] Similarly to what illustrated for the left ventricle prostheses illustrated in
[0142] An assembly of cardiac chamber prostheses according to the invention can also be intended for more than one cardiac chamber.
[0143] By way of example,
[0144] Similarly to what illustrated for the left ventricle prosthesis (shown in
[0145] In particular, for the left atrium prosthesis of
[0146] Other embodiments of the assembly of cardiac chamber prostheses intended for the left ventricle 40 and the left atrium 20 may have, alternatively to or in combination with a hydraulic or pneumatic control through (at least) one pump 340B, an electrical and/or electromagnetic control carried out by an electronic processing unit configured to control the electrical and/or electromagnetic polarisation of the elastic membranes, which are provided with electrodes, of the prostheses of the left ventricle 40 and left atrium 20 similarly to what illustrated for the prosthesis in
[0147] Further embodiments of the assembly of cardiac chamber prostheses may also comprise one or more artificial heart valves. By way of example, and not by way of limitation,
[0148]
[0149] In particular, for the right ventricular prosthesis of
[0150] Similarly to what illustrated for the left ventricle prosthesis (shown in
[0151] Also in this case, alternatively to or in combination with the hydraulic or pneumatic control, the prostheses assembly of
[0152] Moreover, the prostheses assembly of
[0153]
[0154] In particular, for the right atrium prosthesis of
[0155] Similarly to what illustrated for the left ventricle prosthesis (shown in
[0156] Also in this case, alternatively to or in combination with the hydraulic or pneumatic control, the prostheses assembly of
[0157] Also, the prostheses assembly of
[0158] Although the embodiments of the assembly of cardiac chamber prostheses illustrated in
[0159] It must be noted that other embodiments of the cardiac chamber prosthesis according to the invention may comprise primary (and secondary) variable connection elements, optionally elastic ones, which connect the membranes to each other, such as for instance nanotechnological structures configured to assume a configuration included between a contracted configuration, at which the connected membranes are at a first limit distance, and an expanded configuration, at which the connected membranes are at a second limit distance greater than the first limit distance. By way of example, such nanotechnological structures could comprise two bars, each of which has its own ends connected to a respective membrane, which are hinged to each other (optionally in a central area of the bars).
[0160] The cardiac chamber prosthesis, and the related assembly, according to the invention can be equipped with sensors (e.g. mechanical, piezoelectric, or electrical sensors) on the respective elastic membranes configured to detect the pressure variation and the electrocardiogram during the various phases of the cardiac cycle. In this way, adjustments of the volume variation control of the variable volume interspaces could be driven for a better overall physiological performance. For instance, inside the left ventricle, a pressure sensor can allow to process the control signal through the technique known as PRAM (described in document WO 00/64339). This processing can be used to determine the times and amplitudes of variation of the volumes delimited by the inner membranes in the specific cardiac chambers in which the related prostheses are implanted.
[0161] As stated, the cardiac chamber prosthesis, and the related assembly, according to the invention is advantageously controlled through a hydraulic or pneumatic control and/or an electric and/or electromagnetic control, advantageously through an EPROM support memory implanted as in a pacemaker. This can control either one prosthesis or more prostheses implanted in respective one or more of the four cardiac chambers.
[0162] The preferred embodiments of this invention have been described and a number of variations have been suggested hereinbefore, but it should be understood that those skilled in the art can make other variations and changes without so departing from the scope of protection thereof, as defined by the attached claims.