Prosthetic mitral valve coaptation enhancement device

Abstract

The present invention relates to a prosthetic mitral valve device for implanting at the native mitral valve region of a heart. The prosthetic mitral valve coaptation enhancement device comprises a main body consisting of a stentframe and a valve element attached thereto, wherein the main body has a sealing section and a valve-bearing section, the valve-bearing section; the shape of the sealing section of the main body, in the compressed state, has a form that is adapted to the coaptation zone of the native mitral valve during systole, and the sealing section of the main body, the radial rigidity of the stentframe is lower than the radial rigidity of the valve-bearing section; the prosthetic mitral valve coaptation enhancement device further comprises at least one anchoring element, which anchoring element is coupled to the main body and is capable to anchor the main body within the native mitral valve region of a heart.

Claims

1. A prosthetic mitral valve coaptation enhancement device for implanting at the native mitral valve region of a heart, wherein the native mitral valve, having a native annulus and native valve leaflets, can still perform a closing movement, and wherein the prosthetic mitral valve coaptation enhancement device comprising: a main body consisting of a stentframe and a valve element attached thereto, the main body comprising a length and a lumen being defined by a proximal end and a distal end, and configured for placement within the native mitral valve region of the heart, the stentframe being radially compressible to a radially compressed state for delivery into the heart and self-expandable from the compressed state to a radially expanded state, wherein the main body has a sealing section and a valve-bearing section, the valve-bearing section carrying a valve element: wherein the shape of the sealing section of the main body, when compressed by the native valve leaflets, has a form that is adapted to the coaptation zone of the native mitral valve during systole, that in the sealing section of the main body, the radial rigidity of the stentframe is lower than the radial rigidity of the valve-bearing section; and that the sealing section of the main body is configured such that it is smaller than the native annulus of the heart into which the prosthetic mitral valve coaptation enhancement device is to be implanted and such that it contacts the native leaflets only during systole, thereby sealing the mitral annulus during systole and permitting filling of the ventricle through and alongside the prosthetic mitral valve coaptation enhancement device during diastole, thereby minimizing the gradient between the left atrium and ventricle; and that the prosthetic mitral valve coaptation enhancement device further comprises at least one substantially rigid anchoring element, which anchoring element is coupled to the main body and is capable to anchor the main body within the native mitral valve region of a heart.

2. The prosthetic mitral valve coaptation enhancement device of claim 1, wherein the stentframe in the sealing section, in its expanded state, is substantially circular, D- or crescent-shaped and is adapted to the shape of and designed to be placed at the coaptation line of the native valve, wherein the crescent-shape transitions along the length of the main body towards the ventricular section into a substantially round shape.

3. The prosthetic mitral valve coaptation enhancement device of claim 1, wherein the stentframe in the sealing section consists of a flexible structure such, that, in the compressed state, it conforms to the coaptation zone of the native mitral valve during systole, wherein the stentframe, in the sealing section, has a flexibility and rigidity that is lower than the flexibility and rigidity of the valve-bearing section.

4. The prosthetic mitral valve coaptation enhancement device of claim 1, wherein it has a size enabling the sealing section being positionable at the level of the native mitral valve leaflets and the valve-bearing section being positionable distally in the left ventricle.

5. The prosthetic mitral valve coaptation enhancement device of claim 1, comprising a combination of one or more of the anchoring elements as defined in claim 4.

6. The prosthetic mitral valve coaptation enhancement device of claim 1, wherein the anchoring element comprises one or more lengthy substantially rigid connecting elements, the connecting elements comprising a first end, a second end and a length extending there between, wherein the connecting elements, via its/their respective first end/s is/are coupled to the valve-bearing section via the distal outflow end of the main body, and, via its/their respective second end/s, is/are coupleable to the ventricular apex.

7. The prosthetic mitral valve coaptation enhancement device of claim 6, wherein the second end of the anchoring element is coupled to a plug element, which is sized and configured to be positionable in the ventricular apex of the heart, thereby piercing the apex.

8. The prosthetic mitral valve coaptation enhancement device of claim 6, wherein the anchoring element comprises one lengthy substantially rigid connecting element.

9. The prosthetic mitral valve coaptation enhancement device of claim 6, wherein the anchoring element comprises three lengthy substantially rigid connecting elements.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The aforementioned features of the invention and the features still to be explained below are shown in the figures, in which:

(2) FIG. 1 shows a schematic drawing of a human heart;

(3) FIG. 2A-B show a schematic drawing of a detailed atrial view of a mitral valve with a malcoaptation of the leaflets without (B) and with (C) a prosthetic mitral valve coaptation enhancement device according to the invention being implanted into the annulus;

(4) FIG. 3A-B show a schematic drawing of an exemplary non-implanted embodiment of a prosthetic mitral valve coaptation enhancement device according to the invention in the expanded form; and

(5) FIG. 4A-I show schematic drawings of different embodiments of the prosthetic mitral valve coaptation enhancement device according to the invention, with different anchoring elements: FIG. 4A-B: anchoring to the apex; FIG. 4C anchoring in the pulmonary veins; FIG. 4D anchoring in the tissue surrounding the native annulus; anchoring in the atrial FIG. 4E or septal FIG. 4F wall; anchoring via an aortic stent FIG. 4G; anchoring via the atrial appendage FIG. 4H; and FIG. 4I anchoring to the apex without piercing.

DESCRIPTION OF PREFERRED EMBODIMENTS

(6) In FIG. 1, a human heart 50 is depicted, having a right atrium 54, a right ventricle 55, a left atrium 56 and a left ventricle 57. Also depicted in FIG. 1 is a portion of the vena cava superior 52, entering the heart 50 via the right atrium 54, and a portion of the vena cava inferior 53.

(7) In more detail, the superior vena cava 52 returns the blood from the upper half of the body, and opens into the upper and back part of the right atrium 54, the direction of its orifice 52a being downward and forward. Its orifice 52a has no valve.

(8) The inferior vena cava 53, which has a larger diameter than the superior vena cava 52, returns the blood from the lower half of the body, and opens into the lowest part of the right atrium 54, its orifice 53a being directed upward and backward, and guarded by a rudimentary valve, the valve of the inferior vena cava (Eustachian valve, not shown).

(9) The right ventricle 55 has a triangular in form, and extends from the right atrium 54 to near the apex 59 of the heart 50.

(10) The right atrioventricular orifice (not depicted in FIG. 1) is the large oval aperture of communication between the right atrium 54 and ventricle 55, and is guarded by the tricuspid valve 60 comprising three triangular cusps or segments or leaflets 64.

(11) The opening 61 of the pulmonary artery 62 is circular in form, and is placed above and to the left of the atrioventricular opening; it is guarded by the pulmonary valves 63.

(12) As discussed above, the function of the tricuspid valve 60 is to prevent back flow of blood into the right atrium 54; arrows 70 and 71 indicate normal blood flow into the right atrium 54.

(13) The left atrium 56 is smaller than the right atrium 54. The left ventricle 57 is longer and more conical in shape than the right ventricle 55. The left atrioventricular opening (mitral orifice, not depicted in FIG. 1) is placed to the left of the aortic orifice 65, and is guarded by the bicuspid or mitral valve 66.

(14) The aortic opening 65 is a circular aperture, in front and to the right of the atrioventricular opening, and its orifice is guarded by the three aortic valves 67. Reference number 68 designates the aorta.

(15) Separating the left atrial chamber or left atrium 56 from the left ventricle 57, the mitral valve 66 is, as mentioned above, an atrio-ventricular valve, with the mitral annulus 70 constituting the anatomical junction between the ventricle 57 and the left atrium 56; the annulus 70 also serves as insertion site for the leaflet tissue (not shown).

(16) The normal mitral valve 66 opens when the left ventricle 57 relaxes (diastole) allowing blood from the left atrium 56 to fill the decompressed left ventricle 57. During systole, i.e. when the left ventricle 57 contracts, the increase in pressure within the ventricle 57 causes the mitral valve 66 to close, preventing blood from leaking into the left atrium 56 and assuring that all of the blood leaving the left ventricle is ejected though the aortic valve 67 into the aorta 68 and to the body. Proper function of the mitral valve is dependent on a complex interplay between the annulus 70, leaflets and subvalvular apparatus (not depicted in FIG. 1, respectively).

(17) The mitral valve 66 has two leaflets 72, 73 (see FIG. 2), i.e. the anterior 72 and the posterior leaflet 73. As mentioned above, the anterior leaflet 72 has a semicircular shape, and the posterior leaflet 73 has a quadrangular shape. The motion of the anterior leaflet 72 defines an important boundary between the inflow and outflow tracts of the left ventricle 57. The anterior leaflet 72 is attached to two fifths of the annular circumference, while the posterior leaflet 73 is attached to approximately three fifths of the annular circumference. The posterior leaflet 73 has typically two well defined indentations which divide the leaflet 73 into three individual scallops; the indentations aid in posterior leaflet opening during systole.

(18) On the atrial surface of the leaflets 72, 73 there are two zones, the peripheral smooth zone 74 and the central coaptation 75 zone. The two areas 74, 75 are separated by the gently curved coaptation line 76 between the two leaflets 72, 73 evident from atrial view.

(19) Mitral valve 66 regurgitation is present when the valve 66 does not close completely, causing blood to leak back into the left atrium 56.

(20) FIG. 2A shows a schematic drawing of an atrial view onto the mitral valve 66 with malcoapting leaflets 72, 73, the valve not being supported by a prosthetic device according to the invention. As can be seen in FIG. 2A, due to the malcoapting leaflets 72, 73 of the mitral valve 68, a space 77 is left between them, allowing blood flow back into the left atrium upon systole, which is called mitral valve regurgitation.

(21) With the device according to the invention, mitral valve regurgitation can be treated, and placement of an exemplary embodiment 100 of the device according to the invention into the diseased mitral valve of FIG. 2A is depicted in the attached FIG. 28, which is also shown in more detail in FIG. 3A-3B.

(22) In the exemplary embodiment of the prosthetic device 100 according to the invention as shown in FIG. 3A-3B, the device 100 is depicted in its expanded state, i.e. the state the device has when implanted into the heart of the patient to be treated. On the other hand, the compressed state is the state the device 100 is in when being loaded onto a transcatheter delivery system compressing the device 100 for introduction via blood vessels of the body.

(23) The device 100 has, a main body 101, comprising a length 102 and a lumen 103, which lumen is defined between a proximal or inflow end 104 and a distal or outflow end 105. The main body 101 consists of a stentframe 106, which has a sealing section 108 and a valve-bearing section 110 carrying a valve element 111.

(24) As can be seen in FIG. 3A-3B, the stentiframe 106 has diamond-shaped cells, and has a Substantially cylindrical form. The inflow end 104 has a substantially circular, D or crescent shape, adapting to the coaptation zone 75 of the leaflets 72, 73. The D-shape transitions into a round cross section of the stentiframe 106 towards the distal end 105, thus generating the Substantially cylindrical shape of the device. The valve element 111 is located at the distal end 105 of the device. In the embodiment shown in FIG. 3A-3B, the anchoring element 120 is not shown.

(25) FIG. 4A-I show different embodiments for anchoring elements 120 of the device 100 according to the invention, wherein the placement of the device 100 in the annulus of the mitral valve of a patient's heart (without reference numerals for the sake of clarity) is depicted, respectively, to show the respective anchoring mechanism of the different embodiments:

(26) In FIG. 4A, device 100 according to the invention comprises, as anchoring element 120, three lengthy connecting elements 122 each comprising a first end 123 and a second end 124. With their respective first end 123, the connecting elements 122 are connected to the distal (outflow) end of main body 101; the connecting elements 122 are of a generally rigid material and are, via their second end 124 fixed to a plug element 125, the plug element 125 piercing the apex of the heart.

(27) The plug element 125 can be of any inert suitable material that is commonly used in connection with surgical procedures and intended for implantation in the heart of a patient.

(28) FIG. 4B shows an embodiment, where only one bar 122 is used to anchor the device 100 in the annulus of a mitral valve, whereby also the connecting element 122 shown in FIG. 4B is fixed in the ventricular apex via a plug 125.

(29) FIG. 4C shows an embodiment, where the device 100 is anchored in the heart via two expandable structures 126, e.g. self-expanding stent-structures, and substantially rigid connecting elements 129. The expandable structures 126 each comprise a first end 127 and a second end 128, and the substantially rigid connecting elements 129 also comprise a first end 130 and a second end 131, respectively. The respective first ends 130 of the ligament means 129 are fixed to the atrial end 104 of the main body 10, and the respective second ends 131 of the substantially rigid connecting elements 129 are fixed to the second ends 128 of the expandable structures 126, thus connecting the expandable structures with the device 100 of the invention, and, as a consequence, anchoring it in the heart.

(30) FIG. 4D shows a further embodiment for an anchoring element 120 in connection with the device 100 according to the invention. The anchoring element 120, in FIG. 4D, is represented by generally U-shaped attachment arms 132, each of which has a first and a second end 133, 134, the second ends 134 comprising attachment means, preferably selected from a hook, a spike or an arrow, wherein the attachment arms 132, via their first respective end 133 is fixed to the stentframe 106 at the proximal inflow end 104 of the main body 101, and are, via their respective second ends 134, able to anchor the main body in the tissue surrounding the mitral annulus, e.g. via piercing this tissue.

(31) FIG. 4E shows another embodiment for an anchoring element 120 in connection with the device 100 according to the invention. Here, the anchoring element 120 comprises three atrial lengthy connecting elements or means 136, which atrial connecting elements or means 136 comprise a first end 137 and a second end 138, and a length 139 extending there between. The first ends 137 are coupled to the proximal inflow end 104 of the main body 101, and the second ends 138 are coupled to the atrial wall via a plug element 140, which plug element pierces the atrial wall, thereby anchoring the device in the heart.

(32) FIG. 4F shows another embodiment for an anchoring element 120 in connection with the device 100 according to the invention. Here, the anchoring element 120 comprises a septal connecting element/means 142 comprising a first end 143 and a second end 144 and a length 145 extending there between. Via its first end 143, the connecting element 142 is coupled to the distal end 105 of the main body 101, and, via its second end 142 and a plug element 148 to the septal wall, thereby piercing the septal wall and anchoring the device 100 according to the invention.

(33) FIG. 4G shows yet another embodiment for an anchoring element 120 in connection with the device 100 according to the invention. Here, the anchoring element 120 is a stent-based aortic valve prosthesis 150, coupled to the prosthetic mitral valve coaptation enhancement device 100 via connecting means 151 to the distal outflow end 105. The aortic valve prosthesis 150, which is to be positioned in the aortic root comprises a stentframe 153 and, as the case may be, i.e. optionally, a biological valve 152. With this embodiment, both native valves. i.e. the native aortic valve 60 and the native mitral valve 66 can be supported/replaced.

(34) FIG. 4H shows another embodiment for an anchoring element 120 in connection with the device 100 according to the invention. Here, the anchoring element 120 is an expandable structure 154 that is shaped and designed such, that it is positioned within the left atrial appendage 156. The anchoring device 120 shown here also comprises flexible lengthy connecting means 158 coupling the expandable structure 154 with the proximal inflow end 104 of the main body 101.

(35) FIG. 4I shows another embodiment for an anchoring element 120 in connection with the device 100 according to the invention. Here, the anchoring element 120 comprises connecting elements 160, having a first end 161, and a second end 162 extending there between, wherein the elements 160, via their respective first ends 161, are connected to the distal end 105 of the main body 101. Their respective second ends 162 are fixed to a clamping element 163, fixing the second ends 162 intraventricularly without piercing the apex.