Expansion of the prosthetic valve device

Abstract

The expansion device includes expandable arms and a linkage coupled to the expandable arms for expanding the expandable arms from a retracted position to an extended position and for returning the expandable arms to the retracted position, wherein an outward-facing surface of at least one of the expandable arms includes a gripping structure that prevents at least one of the expandable arms from slipping off the narrow portion of the prosthetic valve.

Description

[Technical Field]

[0001] The present invention relates generally to prosthetic valve devices, and more particularly to devices and methods for expanding under-expanded prosthetic (e.g., transcatheter) valve devices. [Background technology]

[0002] Prosthetic heart valves are used to replace a native aortic valve, another transcatheter valve, a surgical heart valve, or a surgically altered heart valve. The prosthetic heart valve is delivered to the desired site (e.g., near the native aortic valve annulus) using any appropriate delivery device. During delivery, the prosthetic heart valve is typically placed in a collapsed state within the delivery device. The delivery device can be introduced into the patient using a transfemoral, transaortic, transclavicular, transapical, transseptal, or other percutaneous approach. Once the delivery device reaches the target site, the prosthetic heart valve is expanded, securing it within the native aortic valve annulus and the calcified native valve leaflets. Once properly positioned inside the aortic valve annulus, the prosthetic heart valve acts as a one-way valve, allowing blood to flow from the left ventricle of the heart into the aorta and preventing blood from flowing in the opposite direction into the ventricle.

[0003] Prosthetic heart valve devices can experience known issues that prevent the device from fully expanding. For example, in endovalve repair procedures, non-compliant stents from previous prostheses can prevent the transcatheter aortic valve (TAV) from fully expanding, resulting in distorted leaflet configuration and adversely affecting the durability and functionality of the TAV.

[0004] In another example, calcification in the native valve prevents the TAV from fully expanding. Summary of the Invention

[0005] The present invention, as described in detail below, aims to provide devices and methods for expanding under-expanded prosthetic valve (eg, transcatheter valve) devices.

[0006] This expansion device can be used to post-expand an underexpanded prosthetic valve frame, such as a transcatheter aortic valve replacement (TAVR) frame. The expansion device can be introduced through an appropriate percutaneous approach, allowing the device to approach the TAVR frame over the valve leaflets. The expansion device is rotated and translated to orient the device's expandable arms to match the frame dimensions that are considered narrow (underexpanded) and require expansion. The expandable arms of the device expand radially outward, exerting a radially outward force on the TAVR frame without endangering the new leaflets or causing occlusion. The expandable arms directly expand or compress radially outward against the stent frame and the outside of the valve leaflets. For example, the expandable arms can extend distally above the leaflets, wrap around the leaflets, and contact the frame just above the annulus level.

[0007] This procedure, which can be performed under fluoroscopy and / or echocardiography, carefully controls the expansion of the arms, and thereby the amount of frame deformation (selective expansion of the frame, not necessarily the entire circumference), to avoid causing annular tears or other damage to the leaflets or other tissues. This procedure can reduce or eliminate leaflet thickening and hypokinesis, known as hypoattenuating leaflet thickening (HALT) or the more severe hypoattenuating affecting motion (HAM).

[0008] The expansion device may include a gripping structure for the expandable arms that prevents the arms from sliding away from the narrow portion of the prosthetic valve toward the wider portion, thereby allowing the device to expand only the underexpanded portion of the prosthetic valve and not the other portions. The expansion device may also have a limiting structure that limits the radial outward expansion of the expandable arms to prevent overexpansion and tearing or other damage to the valve annulus.

[0009] According to non-limiting embodiments of the present invention, an expansion device is provided that includes expandable arms and a linkage coupled to the expandable arms for expanding the expandable arms from a contracted position to an extended position and returning the expandable arms to the contracted position, wherein an outward facing surface of at least one of the expandable arms includes a gripping structure that prevents at least one of the expandable arms from slipping off a narrow portion of a prosthetic valve.

[0010] According to a non-limiting embodiment of the present invention, a method of expanding an under-expanded portion of a prosthetic valve device is provided, comprising: providing an extension device comprising an extendable arm and a linkage coupled to the extendable arm for extending the extendable arm from a retracted position to an extended position and for returning the extendable arm to the retracted position; delivering the expansion device so that the expandable arms are positioned inside the under-expanded portion of the prosthetic valve device; and spreading the expandable arms radially outward using the linkage, thereby applying a radially outward force to the under-expanded portion, thereby correcting the expansion of the under-expanded portion. [Brief explanation of the drawings]

[0011] The present invention will be more fully understood from the following detailed description when read in conjunction with the drawings. [Figure 1] FIG. 1 is a simplified diagram of a prosthetic valve device placed in the heart, such as a TAVR, to replace the native aortic valve. [Figure 2] FIG. 2 is a simplified diagram of an expansion device for expanding a prosthetic valve device, constructed and operative in accordance with a non-limiting embodiment of the present invention. [Figure 3] Figure 3A is a simplified diagram of an expansion device applying an outward radial expansion force to a prosthetic valve device, and Figure 3B is a simplified diagram showing the outward radial expansion force being applied to the narrowest portion of the prosthetic valve device. [Figure 4]4A and 4B are simplified illustrations of an expansion device exerting a radially outward expansion force on a prosthetic valve device at two different positions (two different implantation depths) of the prosthetic valve device. [Figure 5] 5A and 5B are simplified diagrams of the prosthetic valve device before and after expansion, respectively. [Figure 6] FIG. 6 is a simplified diagram of an expansion device for expanding a prosthetic valve device, constructed and operative in accordance with a non-limiting embodiment of the present invention. [Figure 7] FIG. 7 is a simplified diagram of the expansion device of FIG. 6 deployed in situ to apply an outward radial expansion force to the prosthetic valve device. DETAILED DESCRIPTION OF THE INVENTION

[0012] 1, there is shown a prosthetic valve device 1 to be implanted in the heart, such as a TAVR to replace the native aortic valve. The prosthetic valve device 1 has an underexpandable portion 2.

[0013] Referring to FIG. 2, there is shown an expansion device 10 for expanding a prosthetic valve device 1, constructed and operative in accordance with a non-limiting embodiment of the present invention.

[0014] The expansion device 10 may include an expandable arm 12 and a linkage 14 coupled to the expandable arm 12 for expanding the expandable arm 12 from a retracted position to an extended position and for returning the arm to the retracted position.

[0015] The dilation device 10 may be coupled to or part of a catheter 16 for delivery over a guidewire 18, as is well known in the art. The dilation device 10 may have a pigtail end 20, as is known in the art.

[0016] In one example, linkage 14 can move along a guidewire or other elongate structure, as shown by arrow 5, to extend extendable arm 12 to an extended position, as shown by arrow 7. Linkage 14 (or other mechanism) can rotate extendable arm 12, as shown by arrow 8, to orient arm 12 in a desired rotational direction.

[0017] FIG. 3A shows an expansion device 10 exerting an outward radial expansion force, indicated by arrows 7, on the prosthetic valve device 1. FIG.

[0018] FIG. 3B shows an outward radial expansion force 7 being applied to the narrowest portion N of the prosthetic valve device 1.

[0019] 4A and 4B show the expansion device 10 applying a radially outward expansion force 7 to the prosthetic valve device 1 at two different positions (two different implantation depths) of the prosthetic valve device 1. FIGS. 5A and 5B show the prosthetic valve device 1 before and after expansion, respectively. Before expansion, the prosthetic valve device 1 has an under-expanded narrow dimension N, and after expansion, the prosthetic valve device 1 has a corrected dimension N+E.

[0020] Referring to FIG. 6, an example of an expansion device 10 is shown in more detail.

[0021] The extendable arm 12 may be configured with two or more hinge members, such as, but not limited to, first, second, and third hinge members 21, 22, and 23. The first hinge member 21 may be pivotally coupled to a central shaft 24 at a first pivot 25 and to a second hinge member 22 at a second pivot 26. The second hinge member 22 may be pivotally coupled to a third hinge member 23 at a third pivot 27. The third hinge member 23 may be pivotally coupled to the central shaft 24 at a fourth pivot 28.

[0022] Linkage 14 may be coupled to second hinge member 22 at fifth pivot 29 and pivotally coupled to central shaft 24. Central shaft 24 may include two portions separated by a biasing device 30, such as a spring.

[0023] One or more outwardly facing surfaces of the expandable arms 12 may have gripping structures 32 that prevent the arms 12 from sliding away from the narrower portion of the prosthetic valve toward the wider portion. Non-limiting examples of gripping structures 32 include one or more roughened portions (e.g., ridges, knurling, non-smooth texture, etc.), or non-slip or weakly adhesive coatings, which allow the device 10 to expand only in the underexpanded portions and not in the other portions.

[0024] The expansion device 10 may have a limiting structure 34 that limits the radially outward expansion of the expandable arms 12 to prevent excessive expansion and tearing or other damage to the annulus. A non-limiting example of this limiting structure 34 is an abutment 34 located near the fourth pivot 28 that prevents the third hinge member 23 from moving beyond it, thus limiting the outward expansion of the first and second hinge members 21 and 22.

[0025] 7, an expansion device 10 is shown deployed in situ to apply an outward radial expansion force to the prosthetic valve device 1. The expandable arms 12 are rotated to press against targeted structural members 11 of the prosthetic valve device 1, which are selected to receive the corrective expansion force.

Claims

1. An expansion device, It comprises an extendable arm and a link mechanism connected to the extendable arm for extending the extendable arm from a retracted position to an extended position and returning the extendable arm to a retracted position. The expansion device is characterized by having a first operating position in which the expandable arm is positioned inside the under-expanded portion of the artificial valve device, and a second operating position in which the link mechanism applies a radially outward force that causes the expandable arm to expand radially outward relative to the under-expanded portion, thereby correcting the expansion of the under-expanded portion.

2. The expansion device according to claim 1, wherein at least one of the expandable arms having an outer surface has a gripping structure that prevents at least one of the expandable arms from slipping and detaching from the narrow portion or the under-expanded portion of the artificial valve.

3. The expansion device according to claim 2, wherein the grip structure includes one or more roughened surfaces.

4. The expansion device according to claim 2, wherein the grip structure includes an anti-slip or adhesive coating.

5. The extension device according to any one of claims 1 to 4, further comprising a limiting structure that restricts the radially outward extension of the extendable arm.

6. The extension device according to claim 5, wherein the limiting structure is a contact portion to which at least one of the extendable arms can make contact.

7. The extension device according to claim 1, wherein each of the extendable arms is composed of two or more hinge members.

8. The expansion device according to claim 1, wherein the link mechanism is rotatably connected to the expandable arm and rotatably connected to the central shaft.

9. The expansion device according to claim 1, wherein the artificial valve device includes a transcatheter aortic valve replacement (TAVR) device.

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