DEVICE FOR MITIGATING OR PREVENTING PARAVALVULAR LEAKS

One aspect of the present disclosure relates to a device for preventing or mitigating paravalvular leakage associated with a valve replacement procedure. The device can include a first ring, a second ring axially spaced apart from the first ring, at least one pad section extending between the first and second rings, and a plurality of centering wires attached to at least one of the first and second rings.

DETAILED DESCRIPTION

When an element or structure is referred to herein as being “on,” “engaged to,” “connected to,” “attached to”, or “coupled to” another element or structure, it may be directly on, engaged, connected or coupled to the other element or structure, or intervening elements or structures may be present. In contrast, when an element is referred to as being “directly on,” “directly attached to,” “directly connected to,” or “directly coupled to” another element or structure, there may be no intervening elements or structures present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).

The present disclosure relates generally to cardiovascular devices and, more particularly, to devices and methods for preventing or mitigating paravalvular leakage during a valve replacement procedure. As representative of one aspect of the present disclosure,FIG. 1illustrates a device10for preventing or mitigating paravalvular leakage associated with a valve replacement procedure. During an aortic valve replacement procedure, for example, a prosthetic aortic valve is inserted in place of the diseased aortic valve. Upon insertion of the prosthetic aortic valve, the diseased aortic valve leaflets (e.g., calcified leaflets) are displaced outward towards the aortic valve annulus. Since the calcified valve leaflets are hardened and somewhat rigid, an optimal seal is not formed between the prosthetic aortic valve and the commissures of the diseased aortic valve, thereby leading to paravalvular leakage. Advantageously, the present disclosure provides a device10configured to improve seal formation between an implanted prosthetic valve and a native valve annulus by helping to flatten calcified native valve leaflets against the commissures of the diseased valve. Although the present disclosure is described below primarily in terms of preventing or mitigating perivalvular leakage during an aortic valve replacement procedure, it will be appreciated that the device can be used during any valve replacement procedure (e.g., a mitral or tricuspid valve replacement procedure).

A cardiac valve includes any valve that controls the flow of blood through and from the heart. Examples of cardiac valves include the mitral valve, the tricuspid valve and the aortic valve12(FIGS. 2A-B), among others. The aortic valve12functions to prevent the regurgitation of blood from the aorta (not shown) into the left ventricle (not shown) during ventricular diastole (FIG. 2A), and to allow the appropriate flow of blood (cardiac output) from the left ventricle into the aorta during ventricular systole (FIG. 2B). The aortic valve12has three principle components: the annulus14; three leaflets16(also known as flaps or cusps); and commissures18. Each of the commissures18is the site of a junction between adjacent cusps16of the aortic valve12. The three commissures18of the aortic valve12lie at the apex of the annulus14, and are equally spaced around the aortic trunk. The commissures18are composed of collagenous fibers oriented in a radial fashion that penetrate into the aortic intima and are anchored in the media of the aorta. The commissure18between the left and posterior cusps is located at the right posterior aspect of the aortic root, whereas the commissure between the right and noncoronary cusp is located at the right anterior aspect of the aortic root. In a normal aortic valve14, the leaflets16open and close to control the flow of blood into the aorta from the left ventricle of the heart as it beats. In a diseased aortic valve20(FIGS. 3A-B), however, the aortic valve is unable to completely close when the pressure in the left ventricle falls below the pressure in the aorta. This causes blood leakage from the aorta into the left ventricle. In such instances, replacement of the diseased aortic valve20with a prosthetic valve is often necessitated; albeit with risk of certain complications, such as paravalvular leakage.

One aspect of the present disclosure includes a device10(FIG. 1) for preventing or mitigating paravalvular leakage associated with a valve replacement procedure. As shown inFIG. 1, the device10can include a first ring22, a second ring24that is axially spaced apart from the first ring, at least one pad section26extending between the first and second rings, and a plurality of centering wires28attached to at least one of the first and second rings. The device10can be comprised of one or a combination of flexible materials that allow(s) the device to easily transition between a collapsed configuration (FIG. 8) and an expanded configuration (FIG. 1). In the expanded configuration, the device10is shaped and dimensioned to snugly fit within a diseased cardiac valve, such as a diseased aortic valve20.

In another aspect, the first and second rings22and24are axially spaced apart from one another by a distance D. The distance D can be varied so that each of the first and second rings22and24can expand into contact with, and apply pressure to, a native cardiac valve annulus (e.g., when the device10is in the expanded configuration). The distance D can be varied as needed by the skilled artisan (e.g., based on the particular cardiac valve anatomy of a given patient). In some instances, the first and second rings22and24can be axially spaced apart so that the distance D is the same or equal between corresponding points on the first and second rings. In such instances, the first and second rings22and24can be parallel to one another. In other instances, the distance D between a first point on the first ring22and a first corresponding point on the second ring24may be different than the distance D between a second different point on the first ring a second different corresponding point on the second ring. In such instances, the first and second rings22and24can be axially offset from one another. In further instances, the first and second rings22and24can be coaxial with, or substantially coaxial with, one another.

Each of the first and second rings22and24can have a circular shape as shown inFIG. 1; however, it will be appreciated that the first and second rings can have any shape that allows the rings to expand into contact with, and apply pressure to, a native cardiac valve annulus (e.g., when the device10is in the expanded configuration). In some instances, the first ring22can be identically shaped as the second ring24. In other instances, the first ring22can have a different shape than the second ring24. Each of the first and second rings22and24has a diameter. In some instances, the diameter of the first ring22can be equal to the diameter of the second ring24. In other instances, the diameter of the first ring22can be different than the diameter of the second ring24. The first ring22and/or the second ring24can comprise a single continuous filament (e.g., a wire). Alternatively, the first ring22and/or the second ring24can have a braided configuration where, for example, two or more filaments are used to form the ring(s). Each of the first and second rings22and24can be made of one or a combination of materials that allows the rings to expand into contact with, and apply pressure to, a native cardiac valve annulus. Examples of materials from which the first and second rings22and24can be made include metals or metal alloys (e.g., stainless steel, Nitinol, titanium, etc.) and polymers (e.g., PTFE).

In another aspect, the device10includes at least one pad section26that is circumferentially spaced about, and extends longitudinally between, the first and second rings22and24. The number of pad sections26included as part of the device10can vary depending, for example, on the number of commissures of a diseased heart valve. In one example, the device10can include three pad sections26where the device is used as part of an aortic valve replacement procedure. The number of pad sections26, however, need not be dictated by the number of commissures. Thus, the device10can include one, two, three, four, or even more pad sections26. The pad sections26can be circumferentially spaced about the first and second rings22and24by a circumferential distance Cd. In one example, the circumferential distance Cdbetween two pad sections26can be equal to (or about equal to) the circumferential distance Cdbetween two commissures. In some instances, the circumferential distance Cdbetween each pad section26comprising the device10can be equal. In other instances, the circumferential distance Cdbetween each pad section26comprising the device10can be different. In further instances, the circumferential distance Cdbetween first and second pad sections26, as well as the circumferential distance Cdbetween the first pad section and third pad section, can be the same, whereas the circumferential distance Cdbetween the second and third pad sections can be different.

Each pad section26(FIG. 4) includes a length L, a width W, and a thickness T, which is defined by oppositely disposed first and second surfaces30and32. As shown inFIG. 4, each pad section26can have a rectangular shape (e.g., wherein the length L is greater than the width W). It will be appreciated that each pad section26can have other shapes (e.g., square, ovoid, circular, etc.) depending, for example, upon the configuration of the first and second rings22and24. The first surface30of each pad section26is configured to engage a commissure or commissural region, which can include a commissure per se as well as the tissue surrounding the commissure, such as the leaflets and/or valve annulus. For example, the first surface30of each pad section26can be configured to contact a commissure or commissural region so that the pad section substantially fills the commissure. Each pad section26can be made of one or a combination of materials capable of preventing or mitigating blood leakage through a commissure. In one example, each pad section26can be made of one or more materials capable of absorbing blood (e.g., gauze). In another example, each pad section26can be made of one or more materials that are semi-permeable or impermeable to blood (e.g., PTFE).

Each pad section26can be securely attached to the first and second rings22and24in one or a variety of configurations, examples of which are illustrated inFIGS. 5A-C. In some instances, an end portion34of a pad section26can be wrapped around a respective portion of the first ring22, for example, and be secured thereto using one or more fasteners36(e.g., a suture, clip, adhesive, etc.) (FIG. 5A). In other instances, an end38of a pad section26can be directly attached to a respective portion of the first ring22, for example, by looping a suture36(or other suitable fastener) over the first ring and then threading the suture through the pad section (FIG. 5B). In further instances, the first ring22(or the second ring24) can be threaded directly through an end portion34of each pad section26(FIG. 5C). In an alternative configuration of the device10, each pad section26(FIG. 6) can extend a distance beyond a radial plane of each of the first and second ring members22and24to provide optimal coaptation between each pad section and a respective commissure or commissural region.

In another aspect, the device10includes a plurality of centering wires28attached to the first ring22and/or the second ring24. As described in more detail below, the centering wires28can be used assist a medical practitioner (e.g., a surgeon) in positioning and manipulating the device10during a valve replacement procedure. In some instances, each of the centering wires28can be directly attached to the first ring22. It will be appreciated, however, that each of the centering wires28can be attached to the second ring24or, alternatively, that some of the centering wires can be attached to the first ring22while other centering wires are attached to the second ring. Although the device10inFIG. 1is shown as having three centering wires28, it will be appreciated that the device can include any desired number of centering wires. The centering wires28can be made of any one or combination of flexible materials, such as stainless steel or Nitinol.

Each of the centering wires28includes oppositely disposed first and second ends40and42. In some instances, the first end40of each of the centering wires28can be directly attached to the first ring22at an attachment point44near or on the location where a pad section26is located. Each centering wire28can extend from the first end40to the second end42, which terminates at a central point46. The second end42of each centering wire28is attached to the second end of the other centering wires at the central point46. The second end42of each of the centering wires28can be attached at the central point46in any suitable manner, such as by twisting or soldering the second ends together. From the central point46, a guide wire48extends away from each of the centering wires28. The guide wire48can be used to assist in positioning the device10during a valve replacement procedure.

In another aspect, the device10can include a prosthetic valve50(FIG. 7). In some instances, the prosthetic valve50can include a bioprosthetic valve, such as those disclosed in U.S. Patent Pub. Nos. 2006/0195183 A1 and 2006/0259135 A1. In other instances, the prosthetic valve50can include a mechanical valve, such as those disclosed in U.S. Pat. Nos. 6,896,700 and 6,875,230. In further instances, the prosthetic valve50can include a stented prosthetic valve, such as the one shown inFIG. 7. For example, a stented prosthetic valve can comprise a prosthetic valve component50(e.g., a bioprosthetic valve) that is secured within an expandable, stent-like component52. The prosthetic valve50can be secured within the device10prior to a valve replacement procedure. Alternatively, the prosthetic valve50can be delivered to (and subsequently secured within) the device10following implantation of the device.

Another aspect of the present disclosure includes a method for preventing or mitigating paravalvular leakage during a procedure to replace a diseased heart valve. One example of the method is shown inFIGS. 8-9, in which an aortic valve replacement procedure is illustrated. It will be appreciated that the method of the present disclosure is applicable in other valve replacement procedures, such as mitral and tricuspid valve replacement procedures.

One step of the method can include providing a device10configured to prevent or mitigate paravalvular leakage. The device10can be configured in an identical or similar manner as the device illustrated inFIG. 1. Where the device10(FIG. 9) is configured for use in an aortic valve replacement procedure, for example, the device can include a first ring22, a second ring24that is axially spaced apart from the first ring, a first pad section26′ configured to engage a first commissure18′ (or commissural region) of a diseased aortic valve20, a second pad section26″ configured to engage a second commissure18″ (or commissural region) of the diseased aortic valve, a third pad section26″ configured to engage a third commissure18″′ (or commissural region) of the diseased aortic valve, and three centering wires28that are attached to the first ring.

After obtaining an appropriately configured device10, the device is transitioned into the collapsed configuration (FIG. 8). The device10can then be delivered to the diseased aortic heart valve20using a minimally invasive, percutaneous, or open heart procedure. For example, the device10can be positioned within the diseased aortic valve20(as shown inFIG. 8) with the aid of the guidewire48. Using the centering wires28, the device10can then be rotated (if needed) to align the pad sections26′,26″, and26″ with the commissures18′,18″, and18″ of the diseased aortic valve20. This can be done by partially expanding the device10and then adjusting the lateral and/or vertical position of the device as needed. Depending upon the orientation of the device10upon placement in the valve annulus14, however, there may not be a need to partially expand and/or reposition the device.

Once the device10is appropriately positioned within the valve annulus14, the device can be transitioned into the expanded configuration (FIG. 9). In the expanded configuration, the first surface30of each of the pad sections26′,26″, and26″ firmly engages the commissures18′,18″, and18″ (or commissural regions) of the diseased aortic valve20. Also in the expanded configuration, the first and second rings22and24can expand into direct physical contact with the valve annulus14, thereby flattening the valve leaflets16against the annulus. As shown inFIG. 9, each of the pad sections26′,26″, and26″ can fill the respective commissures18′,18″, and18″ so that the blood leakage through the commissures is prevented or mitigated. After the device10is secured within the aortic valve annulus14, the centering wires28can be removed (e.g., severed) from the device. Although not shown, a prosthetic valve (e.g., a stented prosthetic valve) can then be secured within the device10to restore normal blood flow through the valve.

From the above description of the present disclosure, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes, and modifications are within the skill of those in the art and are intended to be covered by the appended claims. All patents, patent applications, and publication cited herein are incorporated by reference in their entirety.