PROSTHETIC VALVE DEVICE FOR TREATMENT OF MITRAL VALVE INSUFFICIENCY

Abstract

The present invention concerns a prosthetic valve device for treatment of mitral valve insufficiency, as well as methods of manufacturing the device. The device comprises a main body with a flexible stent frame and a prosthetic material covering the stent frame at least partially, and a valve structure, wherein the valve structure is formed by wire-elements having elongated loop-structures with prosthesis material attached thereto.

Claims

1. A prosthetic valve device for treatment of mitral valve insufficiency, the prosthetic valve device comprising a main body having a lumen and comprising a tubular flexible stent frame having an inner surface and an outer surface, and the main body further comprising a prosthetic material covering the stent frame at least partially, and wherein the lumen contains a valve structure, wherein the flexible stent frame consists of a plurality of wire-elements, each of the plurality of wire-elements being formed of a single wire, the single wire having a first wire end portion and a second wire end portion, wherein each of the wire-elements has a proximal wire-element portion and a distal wire-element portion, wherein at the proximal wire-element portion an elongated loop-structure is provided, the elongated loop-structure comprising a proximal curve section and a distal curve section and a medium section between the proximal and the distal curve section, wherein the prosthetic material covers the proximal wire-element portion, and wherein the prosthetic material is fixed to the proximal curve section from the inner surface of the stent frame, and fixed to the distal curve section from the outer surface of the stent frame.

2. The prosthetic valve device of claim 1, further comprising a tube-element, the tube-element comprising at least one lumen extending through the tube-element, the lumen being designed for accommodating the first and second wire end portions.

3. The prosthetic valve device of claim 1, wherein the plurality of wire-elements consists of three or more wire-elements.

4. The prosthetic valve device of claim 1, wherein the loop-structure is an open or closed loop-structure.

5. The prosthetic valve device of claim 1, wherein the first and second wire end portions of the wires are being held together, adjacent and distal to the distal curve section, at least over a certain distance, preferably by a crimp-structure or by twisting the wires.

6. The prosthetic valve device of claim 1, wherein the first and second wire end portions are be held together by a sleeve substantially over their entire length adjacent to the distal curve section.

7. The prosthetic valve device of claim 1, wherein the proximal curve section comprises two layers of the wire, and the distal curve section comprises one layer of the wire.

8. The prosthetic valve device of claim 1, wherein crimp-elements are provided connecting the wire-elements with one another.

9. The prosthetic valve device of claim 1, further comprising a tube-element, the tube-element comprising at least one lumen extending through the tube-element, the lumen being designed for accommodating the first and second wire end portions, and wherein the tube-element has multiple lumens extending through the tube-element, such, that each of the first and second wire end portions of the single wires or in pairs is guided through a single lumen of the multiple lumens of the tube-element.

10. The prosthetic valve device of claim 1, further comprising a tube-element, the tube-element comprising at least one lumen extending through the tube-element, the lumen being designed for accommodating the first and second wire end portions, and wherein the tube-element comprises at least or exactly three or six lumens.

11. The prosthetic valve device of claim 1, wherein the wire-elements consist of a shape-memory alloy, preferably Nitinol.

12. The prosthetic valve device of claim 1, wherein the prosthetic material is fixed only to the proximal curve section and the distal curve section.

13. The prosthetic valve device of claim 1, wherein the elongated loop-structure has a substantially oval form.

14. A method for manufacturing a prosthetic valve device, the method comprising the subsequent steps of: a) providing a plurality of wire-elements, preferably three wire-elements, each of the plurality of wire-elements being formed of a single wire having a first wire end portion and a second wire end portion, wherein each of the single wire-elements has a proximal wire-element portion and a distal wire-element portion, wherein at the proximal wire-element portion an elongated loop-structure is provided, wherein each of the elongated loop-structures (comprises a proximal curve section and a distal curve section, and a medium section between the proximal and the distal curve section; b) attaching, preferably sewing, to the proximal curve section a tubular prosthetic material, preferably mammal pericardium, wherein the tubular prosthetic material comprises an inner surface and an outer surface, a first prosthetic material end portion, a second prosthetic material end portion and a medium prosthetic material portion between the first prosthetic material end portion and the second prosthetic material end portion, such, that the wire-elements are attached on the outer surface of the first prosthetic material end portion only, wherein the second prosthetic material end portion and the medium prosthetic material portion remain unattached to the prosthetic material in this attaching step b); c) subsequently inverting the tubular prosthetic material with the inner surface over the elongated loop-structures at the proximal wire-element portion, such, that the second prosthetic material end portion and the medium prosthetic material portion are folded over the elongated loop-structure towards the distal curve section; and d) subsequently attaching the second prosthetic material end portion to the distal curve section of the elongated loop-structure, thus forming the prosthetic valve device.

15. The method of claim 14, further comprising step e): e) threading the respective first wire end portions and second wire end portions into a lumen of a tube-element, the tube-element comprising at least one lumen extending through the tube-element, the lumen being designed for accommodating the first and second wire end portions either singularly or in pairs in respective lumens.

16. The method of claim 14, wherein the tube-element is a multi-lumen tube-element, comprising at least or exactly three or six lumens for accommodating the first and second wire end portions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0081] The aforementioned features of the invention and the features still to be explained below are shown in the figures, in which:

[0082] FIG. 1 shows a schematic drawing of a human heart;

[0083] FIG. 2 shows a schematic drawing of an implanted embodiment of the prosthetic valve device of the invention, placed in the mitral valve region of a mammal heart;

[0084] FIGS. 3A-3H show, in schematic drawings in A to D, the steps of manufacturing an embodiment of the prosthetic valve device of the invention, not drawn to scale; (A) shows a single wire-element, without having attached thereto the prosthetic material; (B) shows the prosthetic material being attached to the proximal curve section of the elongated loop-structure of three wire-elements; (C) shows the step after folding the tubular prosthetic material inside-out over the elongated loop-structures; (D) shows the threading of the wire end portions into a tube-element, leaving a bare stent frame section and having the tube-element spaced apart from the stent frame section covered by the prosthesis material; with four alternative wire-elements shown in (E), (F), (G) and (H);

[0085] FIGS. 4A-4B show two additional embodiments of the prosthetic valve device of the invention, with (A) showing an embodiment having first fixating means, and (B) an embodiment having second fixation means; and

[0086] FIGS. 5A-5D show a schematic drawing of another embodiment of the prosthetic valve device of the invention, similar to the device as shown in FIG. 3F, with the prosthetic material attached to the stent frame in two different views (A) and (B) and without the prosthetic material (C), and a view from the proximal end into the lumen of the device (D).

EMBODIMENTS

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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).

[0097] 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).

[0098] Mitral valve 66 regurgitation is present when the valve 66 does not close completely, causing blood to leak back into the left atrium 56.

[0099] In FIG. 2, an embodiment of a prosthetic valve device 100 of the invention is shown, the prosthetic valve device 100 being placed in the heart of a patient. The prosthetic valve device 100 has a main body 120, that has a substantially cylindrical form and comprises a lumen 121 extending from a main body proximal end 122 to a main body distal end 123. The prosthetic valve device 100 further has a stent frame 112 (see, e.g., FIG. 3B) and a prosthetic material 113 attached to the stent frame 112, as well as a valve structure 116 (see FIG. 3C). The stent frame 112 has an inner surface 112a and an outer surface 112b.

[0100] FIG. 3 shows the elements of an embodiment of the prosthetic valve device 100 in more detail, as well as the manufacturing process of the prosthetic valve device 100 according to the invention. In FIG. 3A, a wire-element 101 is shown, formed of a single wire 102 having a first wire end portion 103 and a second wire end portion 104, as well as a first wire end 103a and a second wire end 104b. The wire-element 101 has a proximal wire-element portion 105 and a distal wire-element portion 106. As can be seen in FIG. 3A, the wire element 101 has an elongated loop-structure 107 formed in the proximal wire-element portion 105. The elongated loop-structure 107, in this embodiment, is formed by winding the wire once, thus creating an oval loop-structure 107. The loop-structure has a diameter d1, taken proximally to distally, that is larger than the diameter d2 taken circumferentially, thus creating the oval form.

[0101] The elongated loop-structure 107 has a proximal curve section 108 and a distal curve section 109, as well as a medium section 110 between the proximal curve section 108 and distal curve section 109.

[0102] As can be seen in FIG. 3A, both wire end portions 103 and 104 extend towards the same direction, i.e., the distal/outflow direction, which is opposite to the direction the elongated loop-structure is provided.

[0103] Herein, i.e. throughout the invention, with the term “wire ends” 103a, 104a the very ends of the wires 102 are designated, wherein with “wire end portions” 103, 104 a section of the respective wire 102 directly adjacent to the specific wire end 103, 104 is designated, although at some passages, when used alternatively, it will be obvious which of the two alternatives, i.e. the very end or an “end portion”/end section is meant.

[0104] When manufacturing a prosthetic valve device 100 of the invention, at least two, preferably three of the wire-elements 101 are provided, preferably made from nitinol, wherein the elongated loop-structure 107 is generated such, that each of the wire-elements 101 is winded around, e.g., two pins that are spaced from one another in a certain, desired distance, which distance regulates the diameter d1 of the elongated loop-structure 107. Upon heating the wire-elements, they retain the elongated loop-structure 107.

[0105] Next, and this can be seen in FIG. 3B, three wire-elements 101a, 101b, 101c are attached two a prosthetic material 113. The prosthetic material 113, as shown in FIG. 3B, is tubular, i.e., formed like a tube, and has an outer surface 114 and an inner surface 115, and a first prosthetic material end portion 113a, and a second prosthetic material end portion 113b. The three wire-elements 101a, 101b and 101c are fixed, preferably sewn, to the outer surface 114 of the prosthetic material 113, at its first prosthetic material end portion 113a such, that the proximal curve section 108 of the elongated loop-structures 107 of the wire-elements 101a, 101b and 101c cover about a third of the prosthetic material 113. As can be seen in the embodiment shown in FIG. 3, the three wire-elements 101a, 101b and 101c are attached by sewing them onto the outer surface 114, such, that they are arranged in a triangle-like fashion circumferentially surrounding the tubular prosthetic material 113 at its first prosthetic material end portion 113a.

[0106] In order to generate the valve structure 116, the tubular prosthetic material 113 is inverted, or folded over the proximal curve section 108 of the elongated loop-structures 107, as indicated by the arrows 117 in FIG. 3B, and pulled down over the wire-elements as far as the distal curve sections 109 of the elongated loop-structures 107. In doing so, the inner surface 115 of the tubular prosthetic material 113 gets turned inside-out, and covers the elongated loop-structures 107.

[0107] In a next step, as can be seen in FIG. 3C, the second prosthetic material end portion 113b is fixed/attached, preferably sewn to the distal curve sections 109 of the elongated loop-structures 107. In the embodiment shown in FIG. 3, only the second prosthetic material end portion 113b of the tubular prosthetic material 113 is fixed to the elongated loop-structures, so that a medium portion 113c of the tubular prosthetic material 113 remains unattached, allowing the tubular prosthetic material 113 to get inflated in a balloon-like fashion during systole, thus supporting the abutment of the prosthetic valve device 100 to the native mitral valve.

[0108] With this step, i.e. inverting or folding the tubular prosthetic material 113 over the proximal curve section 108 of elongated loop-structures 107, a valve structure 116 is generated which is positioned at the attachment site of the first prosthetic material end portion 113a of the prosthetic material 113, which is generally located at the proximal curve section 108, but distanced from the very proximal end 111 of the elongated loop-structures 107 at a distance X (see FIG. 3B). At this distance, now inside the main body 120, the valve structure 116 is generated.

[0109] The first and second end portions 103, 104 of the wire-elements, extend the towards the wire-elements distal portion 106.

[0110] FIG. 3D shows a last step of assembling a prosthetic valve device 100 according to an embodiment of the invention, where the first and second ends portions 103, 104 of the wire-elements 101a, 101b, 101c are introduced/guided/threaded into a tube-element 130. The tube-element 130, shown in the embodiment in FIG. 3B, has multiple lumens 131. According to this embodiment, the number of lumens 131 corresponds to the number of first and second end portions 103, 104 of the wire-elements 101. As can be also seen in FIG. 3D, the tube-element 130 is placed in a distance of the distal curve of the elongated loop-structures 107, so as to generate a bare stent frame section 132.

[0111] In providing the tube-element 130 accommodating the wire-elements 101, it can be advantageously avoided, that the ends/end portions 103, 104, 103a, 104a, cause injuries of the heart tissue. Also, friction of the wire end portions 103, 104, which outwears the wire-elements 101, can be avoided.

[0112] FIGS. 3E, 3F, 3G and 3H show alternative embodiments of the wire-element of the prosthetic device of the invention.

[0113] As can be seen in the embodiments 3E and 3F, the proximal curve sections 108 are bent outwardly, in respect to longitudinal axis A (see FIG. 3F). Further, as also can be taken from FIGS. 3E and 3F, the stent frame 112 is generated such, that three wire-elements 101 are provided, which are connected to one another by crimp-elements 140. The crimp-elements 140 are provided adjacent to the proximal curve section 108, joining left and right wire portions 136, 137 of two different wire-elements 101 together, respectively.

[0114] In FIG. 3E, the loop-structures 107 of the wire-elements 101 are formed by a wire 102 being bent in a proximal curve section 108, with a substantially straight medium wire section 110, represented by a left wire portion 136 and a right wire portion 137, respectively, which extend into the distal curve section 109. Towards the distal curve section 109, the left and right wire portions 136, 137, are guided or bend towards one another, thus forming the distal curve section 109. In the distal curve section 109 of the embodiment shown in FIG. 3E, the left and right wire portions 136, 137 are not connected to one another, whereby the generated loop-structure 107 has an “open” loop, with the first and second wire end portions 103, 104 extending separately in the distal wire-element portion 106.

[0115] In an alternative embodiment shown in FIG. 3F, which in the general assembly is similar to the one shown in FIG. 3E, the first and second wire end portions 103, 104 are—in pairs—guided/provided in a sleeve 141, distal to/adjacent to the distal curve section 109. As a consequence, the first and second wire end portions 103, 104, will—when the prosthetic device is completely assembled—be guided into the tube-element 130 (not shown in FIGS. 3E to 3H) in a pair-wise fashion, i.e. into three lumens 131 of the tube-element 130, while in the embodiment shown in FIG. 3E, six lumens 131 are provided in the tube-element 130 (not shown in FIG. 3E), when threading the first and second wire end portions 103, 104 singularly into the respective lumens 131.

[0116] Turning now to FIGS. 3G and 3H, yet other embodiments of a wire-element 101 used in the device 100 according to the invention are shown. The wire-elements 101 shown in FIGS. 3G and 3H, respectively, also comprise a elongated loop-structure 107 having proximal curve section 108, a distal curve section 109, and a medium wire section 110.

[0117] While the first and second wire end portions 103, 104, in the embodiment shown in FIG. 3G, are brought together distal to the distal curve section 109 by crimping together via a crimp-structure 142.

[0118] Alternatively, and this is shown in FIG. 3H, the first and second wire end portions 103, 104 are—distal to the distal curve section 109—twisted together.

[0119] In both embodiments, the first and second wire end portions 103, 104 can either be separately be guided into a tube-element 103, or in pairs.

[0120] In a preferred embodiment, the proximal curve section, with reference to the proximal-distal length axis and/or the lumen, is bent outwardly.

[0121] According to another embodiment of the prosthetic device of the invention, the wire-elements are attached to one another, preferably via crimp-elements crimping together the wire-elements.

[0122] According to an refinement of this embodiment, at least one, two, three four, five or six, crimp-elements are provided, preferably adjacent to the proximal curve section, wherein further preferably one crimp-element connects a left and a right wire section of two different wire-elements.

[0123] With this embodiment, a more stable connection/assembly of the wire-elements as such can be provided. Accordingly, in case of three wire-elements, three crimp-elements are needed to attach the wire-elements to one another.

[0124] According to a refinement of the invention, the prosthetic valve device of the invention further comprises a tube-element, the tube-element comprising at least one lumen extending through the tube-element, the lumen being designed for accommodating the distal wire-element portion, and preferably for accommodating the first and/or second wire end portions singularly or in pairs.

[0125] FIG. 4 shows two different possibilities for fixating the prosthetic valve device 100 in the heart of a patient, with FIG. 4A showing an exemplary embodiment that can be used when trans-apically implanting the prosthetic valve device 100 of the invention, and FIG. 4B when trans-septically implanting the prosthetic valve device 100 of the invention.

[0126] The trans-apical implantation is effected by a small surgery to access the apex of the left ventricle and the prosthetic valve device 100 is deployed using a trans-apical catheter (not shown). The tube-element 130 is fixed to the apex in an apical anchor 133 which can grab the tube-element 130 in the desired position. The tube-element 130 can be moved in the anchor 133 to the best coaptation position and fixed, e.g., in a plug-like fashion.

[0127] The trans-septal implantation requires a catheter (not shown) that delivers the prosthetic valve device 100 via the femoral vein, right atrium, cross septum, left atrium, crossing mitral valve, until the catheter tip reaches the left ventricle apex from inside. Using a mechanism to slide and lock the wires out of the tube-element the wire-elements can be hooked to the myocardium via hooks 135.

[0128] FIG. 5 shows another embodiment of a prosthetic device of the invention, which is similar to the device as shown in FIG. 3F, and, accordingly, the same features are designated with the same reference signs. FIGS. 5A and 5B each show a side view of the embodiment, with the prosthetic material 113 attached to the stent frame 112. FIG. 5C shows the stent frame 112 of the embodiment without the prosthetic material 113 being attached to the stent frame 112, and FIG. 5D shows a view into the lumen 121 of the device 100 of this embodiment, displaying the valve structure 116.

[0129] As can be seen, the proximal curve sections 108 are slightly bent outwardly, in respect to longitudinal axis A. Further, the stent frame 112 is generated such, that three wire-elements 101 are provided, which are connected to one another by crimp-elements 140a, 140b at two different positions, i.e., a more proximal one 140a and a more distal one 140b. The proximal crimp-elements 140a are provided adjacent to the proximal curve section 108, joining left and right wire portions 136, 137 of two different wire-elements 101 together, respectively. The distal crimp-elements 140b are provided proximal to the distal curve section 109, in a certain distance from the proximal crimp-element 104a.

[0130] In the embodiment shown in FIG. 5, the two wire elements 101—or rather their left and right wire portions 136, 137—crimped together by the proximal and the distal crimp-elements 140a, 140b, form, in between the distance of the proximal and the distal crimp-elements 140a, 104b, a generally oval single-cell-structure 146. Distally of the distal curve section 109, the first and second wire end portions 103, 104 of each of the three wire elements 101 are crimped together by a third crimp-element 140c. Also depicted in FIG. 5. is the prosthetic material 113 being fixed to the stent frame 112 with a valve 116 being formed inside the lumen 121 (see FIG. 5C).