HK40003966B - Heart chamber prosthetic valve implant with elevated valve section and single chamber anchoring for preservation, supplementation and/or replacement of native valve function - Google Patents

Description

A cardiac chamber prosthetic valve implant with an elevated valve segment and univentricular anchoring for maintaining, supplementing, and/or replacing native valve function

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Serial No. 62/373,541, filed on August 11, 2016, entitled “HEART CHAMBER PROSTHETIC VALVE IMPLANT WITH STENT, SPRING AND DOME SECTIONS,” U.S. Provisional Application Serial No. 62/373,560, filed on August 11, 2016, entitled “HEART CHAMBER PROSTHETIC VALVE IMPLANT WITH STENT, MESH AND DOME SECTIONS,” and U.S. Provisional Application Serial No. 62/373,551, filed on August 11, 2016, entitled “HEART CHAMBER PROSTHETIC VALVE IMPLANT WITH ELEVATED VALVE SECTION,” the entire contents of each of which are incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

not applicable

Technical Field

The present invention relates to devices and methods for implanting devices within heart chambers. More particularly, the present invention relates to a univentricular anchoring frame comprising an anchoring structure positioned entirely within a univentricular chamber and a prosthetic valve positioned to maintain and/or replace native valve function.

Background Art

The human heart consists of four chambers and four heart valves that facilitate forward (antegrade) blood flow through the heart. The chambers include the left atrium, left ventricle, right atrium, and left ventricle. The four heart valves include the mitral valve, tricuspid valve, aortic valve, and pulmonary valve. See Figure 1 for general information.

The mitral valve is located between the left atrium and the left ventricle and helps control the flow of blood from the left atrium to the left ventricle by acting as a one-way valve to prevent backflow into the left atrium. Similarly, the tricuspid valve is located between the right atrium and the right ventricle, while the aortic valve and the pulmonary valve are semilunar valves located in the arterial flow of blood leaving the heart. The valves are all one-way valves, with leaflets that open to allow forward (antegrade) blood flow. Normally functioning valve leaflets close under the pressure exerted by the reverse blood to prevent blood from flowing back (retrograde) into the chamber that just flowed out. For example, the mitral valve provides a one-way valve between the left atrium and the left ventricle when working normally, opening to allow antegrade flow from the left atrium to the left ventricle, and closing to prevent retrograde flow from the left ventricle into the left atrium. This retrograde flow (when present) is called mitral valve regurgitation or mitral valve regurgitation.

FIG2 illustrates the relationship between the left atrium, the annulus, the chordae tendineae, and the left ventricle relative to the mitral valve leaflets. As shown, the upper surface of the annulus forms at least a portion of the bottom or lower surface of the left atrial chamber, and thus, for the purposes of this description, the upper surface of the annulus is defined as marking the lower boundary of the left atrial chamber and is generally represented by at least one point A that indicates the general location of an implant target that rests or is mounted on a designated upper annular surface (the designations of which are discussed in detail below). In practice, more than one point A may be used to designate the upper annular surface so that the anchoring structure and the prosthetic valve are positioned within a single heart chamber and do not interfere with the native valve leaflets.

The area of the annulus through which blood flows in a generally downward antegrade direction between the left atrium and the left ventricle, but above the inflection point of the native leaflets, is referred to herein as the inner annulus. Reference will be made to Figures 7A and 7B for sectional side views of the annulus, the native leaflets, the designated upper annular surface, and the inner annulus. Note that the designated upper annular surface described above defines the lower boundary of at least a portion of the left atrium. Thus, the designated upper annular surface may also extend across the annulus itself, for example, covering the annular plane as is well known to those skilled in the art. However, as further described below, the designated upper annular surface may also extend downward (antegrade) into the annulus for a distance, but may not extend downward (antegrade) beyond a position where any structure placed at the designated upper annular surface may adversely affect the function of the native valve leaflets within the inner annulus, for example, at the inflection point of the native valve leaflets.

Native heart valves may malfunction or become dysfunctional due to a variety of reasons and/or conditions, including but not limited to disease, trauma, congenital malformations, and aging. These types of conditions may result in the valve structure not closing properly, resulting in retrograde blood flow from the left ventricle to the left atrium in the event of mitral valve failure. Figures 3 and 4 illustrate retrograde blood flow in the event of a dysfunctional mitral valve. Figure 4 illustrates a prolapsed native valve with loss of coaptation between the leaflets and, therefore, retrograde blood flow from the left ventricle to the left atrium.

Mitral regurgitation is a specific problem caused by a dysfunctional mitral valve that allows at least some retrograde blood flow from the right atrium back into the left atrium. In some cases, the dysfunction is caused by the mitral valve leaflet(s) prolapsing upward into the left atrial chamber (i.e., above the upper surface of the annulus designated by line or plane A, rather than being connected or coapted to prevent retrograde flow). This backflow of blood places a strain on the left ventricle, with a volume load that can result in a series of compensatory left ventricular adaptations and adjustments (including remodeling of the ventricular chamber size and shape), which vary greatly over the long-term clinical course of mitral regurgitation.

Therefore, native heart valves (e.g., mitral valves) may often require functional repair and/or assistance (including partial or complete replacement). Such interventions can take several forms, including open heart surgery and open heart implantation of a replacement heart valve. See, for example, U.S. Patent No. 4,106,129 (Carpentier) for highly invasive procedures fraught with patient risk, requiring not only prolonged hospitalization but also a very painful recovery period.

Minimally invasive methods and devices for replacing dysfunctional heart valves are also known and involve percutaneous access and catheter-assisted delivery of replacement valves. Most of these solutions involve replacement heart valves attached to structural supports (e.g., stents known in the art), or other designs in the form of a wire network that expands when released from a delivery catheter. See, for example, U.S. Patent No. 3,657,744 (Ersek); U.S. Patent No. 5,411,552 (Andersen). Self-expanding variants of support stents help to position the valve and keep the expanded device in the proper position within the subject's heart chamber or blood vessel. This self-expanding form also presents problems when the device is not properly positioned in the first placement attempt (which is often the case), and therefore must be recaptured and repositioned. In the case of a fully or even partially expanded device, this recapture process requires re-collapsing the device to a position that allows the operator to retract the deflated device into the delivery sheath or catheter, adjust the inlet position of the device, and then re-expand to the proper position by redeploying the position-adjusted device to the distal side of the delivery sheath or catheter. Deflation of an already expanded device is difficult because the expanded stent or wire network is typically designed to achieve an expanded state that also resists contraction or deflation forces.

In addition to the open heart surgical approaches discussed above, access to the valve of interest is achieved percutaneously via at least one of the following known access routes: transapical delivery techniques; transfemoral delivery techniques; transatrial delivery techniques; and transseptal delivery techniques.

Generally, the art is focused on systems and methods that utilize one of the aforementioned known access routes to allow for the partial delivery of a deflated valve device, wherein one end of the device is released from a delivery sheath or catheter and expanded for initial placement, and then fully released and expanded when proper placement is achieved. See, for example, U.S. Patent Nos. 8,852,271 (Murray, III), 8,747,459 (Nguyen), 8,814,931 (Wang), 9,402,720 (Richter), 8,986,372 (Murray, III), and 9,277,991 (Salahieh); and U.S. Patent Publication Nos. 2015/0272731 (Racchini) and 2016/0235531 (Ciobanu).

Furthermore, all known prosthetic heart valves are intended to completely replace the native heart valve. Thus, in the case of the mitral valve, these replacement heart valves and/or anchoring or tethering structures physically extend beyond the left atrial chamber and engage the inner valve annulus and/or valve leaflets, in many cases pressing the native leaflets against the wall of the inner valve annulus, thereby permanently eliminating all remaining function of the native valve and rendering the patient completely dependent on the replacement valve. Furthermore, certain embodiments may also include physical expansion and implantation structures that do not extend into one or more pulmonary arteries. In other cases, the anchoring structure extends into the left ventricle and may be anchored into the left ventricular wall tissue and/or a sub-annular surface of the left ventricular apex.

Improvements are needed for each prosthetic valve implantation solution that requires extension, attachment, anchoring, manipulation and/or fluid communication, operative connection and/or engagement with tissue, valves and/or passages and/or chambers outside the left atrium while reducing or eliminating the associated native valve function. For convenience, these solutions are collectively referred to herein as dual-chamber solutions. Generally speaking, when the native valve leaflets retain some function, the preferred solution is one that maintains and/or preserves the native function of the heart valve, and thus it is preferred to supplement or enhance the native valve and its function rather than completely replace it.

Obviously, there are situations where the native valve has almost completely lost function prior to an interventional implantation procedure. In such cases, a preferred solution would include an implant that does not extend beyond, for example, the left atrium and that serves to completely replace the function of the native valve. However, in many other cases, the native valve remains functional to some extent and may or may not continue to lose function after the implantation procedure. In such situations, a preferred solution would include delivering and implanting a valve device that can serve both to supplement or augment the valve without damaging the native leaflets so as to preserve native valve leaflet function for as long as they exist, while also being able to completely replace the native function of a valve that has slowly lost most or all of its function after the prosthetic valve is implanted. Additionally, certain embodiments may also include a physical expansion and implant structure that does not extend into or engage with one or more pulmonary arteries.

Dual chamber solutions present other problems. They are unnecessarily bulky and long, making delivery and placement/recapture/repositioning more difficult from a strictly structural standpoint. Furthermore, dual chamber solutions present difficulties in making the ventricular anchoring and/or tethering connections required to maintain position. Moreover, these solutions interfere with native valve function, as described above, because the portion of the device that is positioned within the left ventricle must pass transannularly, through the inner annulus and at least a portion of the native mitral valve, thereby necessarily permanently disrupting and, in some cases, eliminating any remaining coaptation and function of the native leaflets. Additionally, many dual chamber solutions typically require invasive anchoring of some native tissue, resulting in unnecessary trauma and potential complications.

Unless otherwise noted, certain inventive embodiments described herein are readily applicable to single-chamber or dual-chamber solutions. Additionally, certain embodiments discussed herein may be generally applicable to preserving and/or replacing native valve function and are therefore not limited to the mitral valve.

Various embodiments of several of the inventions disclosed herein address these issues, among other things.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows certain features of the heart in cross-section.

FIG2 shows a cut-away perspective view of the left side of the heart.

3 shows a cross-sectional view of the heart illustrating retrograde blood flow caused by mitral regurgitation compared to normal blood flow.

4 shows a cross-sectional view of a portion of a heart illustrating prolapsed mitral valve leaflets and regurgitant blood flow.

FIG. 5A shows a top view of the annulus and one embodiment of the present invention.

Figure 5B shows a cross-sectional side view of the annulus and native leaflets and one embodiment of the present invention.

Figure 5C shows a cross-sectional side view of the annulus and native leaflets and one embodiment of the present invention.

Figure 5D shows a cross-sectional side view of the annulus and native leaflets and one embodiment of the present invention.

Figure 5E shows a cross-sectional side view of the annulus and native leaflets and one embodiment of the present invention.

FIG6 shows a perspective view of one embodiment of the present invention.

FIG7 shows a perspective view of one embodiment of the present invention.

FIG8 shows a bottom view of one embodiment of the present invention.

FIG9 shows a cutaway perspective view of one embodiment of the present invention.

FIG. 9A shows a perspective view of one embodiment of the present invention.

FIG. 10 shows a cutaway perspective view of one embodiment of the present invention.

FIG. 11 shows a perspective view of one embodiment of the present invention.

FIG. 12 shows a perspective view of one embodiment of the present invention.

FIG. 13 shows a perspective view of one embodiment of the present invention.

FIG14 shows a perspective, partially cut-away view of one embodiment of the present invention.

FIG. 15 shows a perspective, partially cut-away view of one embodiment of the present invention.

DETAILED DESCRIPTION

Various embodiments of the present invention include single-chamber anchoring solutions that include (1) maintaining native valve function; (2) initially maintaining native valve function and then completely replacing native valve function; (3) completely replacing native valve function; and (4) reducing the prolapse distance of the dysfunctional leaflet by preventing the prolapsed leaflet from deviating anteriorly above the superior annular surface and into the left atrial chamber so as to maintain native leaflet function for as long as possible.

As discussed, known prosthetic heart valves are intended to completely replace native heart valves. Consequently, these replacement heart valves physically engage the inner annulus and/or valve leaflets, in many cases pressing the native leaflets against the walls of the inner annulus, thereby eliminating all remaining function of the native valve and rendering the patient completely dependent on the replacement valve. Generally speaking, when the native valve leaflets retain some function, the preferred solution is one that maintains and/or preserves the native function of the heart valve, thus preferably supplementing or enhancing the native valve and its function rather than completely replacing it.

In some cases, the native valve has almost completely lost its function before the interventional implantation procedure. In this case, the preferred solution provides a complete functional replacement for the native valve.

In other cases, the native valve will retain some function after implantation of a prosthetic valve, but will continue to lose native function over time. Therefore, in these cases, a preferred solution involves delivering and implanting a valve device that will initially serve as a supplemental valve to maintain and preserve native valve leaflet function as long as it exists, and gradually serve as a replacement for the native valve function over time as the valve slowly loses native function. Therefore, in these cases, a preferred solution may initially maintain native valve function, requiring only a lower level of supplemental or augmented support, and provide gradually increasing levels of supplemental or augmented support to accommodate the increasing need for replacement as native leaflet function slowly deteriorates. Ultimately, a preferred solution may provide complete replacement function.

In this regard, various embodiments of the present invention feature the prevention of prolapsed valve leaflets from rising above the superior annular surface and into the left atrium in order to provide additional support to native leaflet function and maintain that additional support for as long as possible.

Additionally, the univentricular expansion and implant device structures include certain embodiments as shown in the accompanying drawings. Thus, these embodiments of the expansion and implant device structures may not include structures that extend below a boundary (e.g., an annular plane as shown in the accompanying drawings and referred to in the art). Alternatively, as further discussed, within the annular throat, no structures may extend below a defined boundary. Still alternatively, certain embodiments may not include structures that extend outside of a cardiac chamber (e.g., the left atrium) into a vessel in fluid communication therewith (e.g., the pulmonary artery as shown in the accompanying drawings).

Thus, in some embodiments, the expansion and implantation structure in the left atrium may not include structure present in or engaged with one or more of the patient's mitral valve, left ventricle, and pulmonary artery, including native leaflets.

Furthermore, embodiments of the present invention may include delivering a deflated prosthetic heart valve structure to a heart chamber (e.g., the left atrium) that does not include structure present in or engaged with one or more of the patient's mitral valve, left ventricle, and pulmonary artery, including native leaflets.

Various embodiments of the present invention include preferred solutions for each of the above situations.

Referring now to Figures 5A-5E, a specified location or portion of the upper or upper annular surface of the annulus can be achieved by specifying at least two points A, each of which must be located at the now specified location on the upper annular surface. As best seen in Figures 5A and 5B, plane B represents a plane that is generally flat and colinear with at least two specified points A located on the specified upper surface of the annulus of the left atrium. A key and necessary feature of the specified at least two points A requires that they be located above the bend point FP of the native valve leaflet. This arrangement, in turn, helps to locate the lowest portion of the structure that extends across the annulus or, in some cases, into the inner annulus. Thus, a structure having a lowest portion located on or above the specified at least two points will not adversely interfere with the remaining normal native valve function. Those skilled in the art will recognize plane B as shown in Figure 5B as being generally on or colinear with what is commonly referred to as the annular plane, but as described below, other locations may also be specified for the upper annular surface, each of which is within the scope of the present invention.

Furthermore, the lowest point or bottom of the left atrium and/or left atrial chamber relative to the annulus (including the inner annulus in certain embodiments) is defined herein as being located by at least one line (straight or curved) connecting at least two designated points A. Thus, in the case of a curve or a series of lines that can be curves, a generally flat plane such as plane B can form a curvilinear slice C as shown in FIG. 5B and can include a change in curve across slice C.

A structure having a lowermost portion positioned at or above an upper annular surface defined and designated by at least two designated points A and a flat plane B or curvilinear slice C connecting the at least two points is defined herein as being within the left atrium or left atrial chamber.

Structures positioned below the annular superior surface defined by at least two designated points A and the plane B or curvilinear sheet C connecting the at least two points are defined herein as being outside the left atrium or left atrial chamber.

The definition of the lower boundary of the left atrium relative to the annulus, and the corresponding definition of the interior and exterior of the lower boundary of the left atrium, requires, in addition to specifying at least two points, that the locations of the at least two specified points A and the corresponding plane B or curved sheet C must not adversely interfere with the function of the native valve leaflets at any time. As will be readily appreciated by those skilled in the art, the remaining boundaries of the left atrium or left atrial chamber include the chamber wall and the upper surface or roof. This definition of the boundaries of the left atrium or left atrial chamber now forms the basis for positioning and anchoring structures solely within the left atrium or left atrial chamber, without any anchoring or other structures extending beyond the defined boundaries of the left atrium or left atrial chamber.

We note that, depending on the depth within the inner annulus of the designated upper annular surface as described above, the lowest portion of the various embodiments of the prosthetic heart valve devices described herein can, in some embodiments, provide a barrier to a prolapsed mitral valve, thereby preventing prolapse to varying degrees. This is one of the inventive purposes of various embodiments of the present invention. However, the lowest structure of each embodiment that can extend downward into the inner annulus must be located on or above the upper annular surface of the design as defined herein.

It should be understood that, as shown in the accompanying drawings, at least two designated points A and the plane B or curvilinear sheet C connecting the at least two designated points are always located above the bend point FP of the native leaflet. This is one of the features that allows, in certain circumstances, to prevent prolapse of the native leaflet to varying degrees and at the same time does not adversely interfere with native leaflet function. Note that in Figure 5C, the portion of the curvilinear sheet C that extends across the annulus can bend or tilt downward below what is generally referred to as the annular plane so that the designated upper annular surface can include a downward extension or offset into the inner annulus. Such a construction is within the scope of the present invention as long as the curvilinear sheet C remains in compliance with the above-mentioned requirements for the designated upper annular surface at all points (e.g., located above the bend point PF of the native leaflet) so as not to interfere with native function.

Alternatively, at least a portion of the lower surface 106 of the base segment 100 may also rest on the lower surface of the left atrium surrounding at least a portion of the annulus.

In yet another set of alternative embodiments, a portion of the upper annular surface can be designed to extend below the bend point FP of the native leaflets while still maintaining their native function, as long as at least partial coaptation of the leaflets can be achieved. Furthermore, in cases where the native leaflet function is assessed to be very poor, the valve structure can be extended downwardly through the inner annulus to effectively press the native leaflets against the wall tissue. This is only a possible solution in rare cases, but it is within the scope of the presently described invention. In this embodiment, the upper annular surface is also defined and designated at a position below the bend point of the native leaflets.

The relationship and definition of the annular upper surface to at least two designated points A and plane B are further illustrated in Figures 5D and 5E. Here, the annulus is shown in side cross-section, with the inner annulus depicted as the inner channel of the annulus having a height H. Figure 5D illustrates the annular upper surface, with the corresponding plane B generally aligned with the annular plane. Figure 5E illustrates an alternative embodiment in which the annular upper surface is designated slightly lower than that shown in Figure 5D and designated plane B'. However, in each case, the annular position and location, as indicated by plane B and/or curvilinear slice C, specifying the upper surface must be above the inflection point FP of the native leaflets so that at least the implanted lower surface 106 of the base segment 100 resting on the annular upper surface does not interfere with native leaflet function. This alternative embodiment further illustrates multiple designated points A and associated planes B or curvilinear slices C for positioning and locating the annular upper surface, and therefore, the lower surface 106 of the base segment 100, during implantation.

Turning now to Figures 6 and 7, one embodiment of the present invention is shown comprising a collapsible and expandable anchoring structure 10 comprising a base stent 100 having an expandable and collapsible mesh or mesh as known in the art, an intermediate spring-like segment 200, and an atrial dome 300, wherein the intermediate spring-like segment 200 is operatively connected to the base stent 100 and the atrial dome 300. Figure 5 shows the anchoring structure 10 within the left atrium and not containing, engaging, or interfering with structures outside the left atrium.

The base segment 100 includes an inner surface 102, an outer surface 104, a lower surface 106 having a diameter D1, an upper surface 108 having a diameter D2, and a height H1 generally defined as the vertical length between the lower surface 106 and the upper surface 108. As is well known, the base segment 100 can include a stent or other structure capable of collapsing and expanding. The base segment 100 is preferably biased to expand from a collapsed state to an expanded state, but other collapsed-to-expanded mechanisms may also be used. In addition, the base segment 100 can achieve multiple expanded states so as to expand and contract with the natural movement of the heart chamber walls and floor. The base segment 100 can include a shape memory material (e.g., nitinol or a similar wire mesh structure or sliding element structure) that is biased to achieve the expanded state(s) as is known in the art. Similarly, a shape memory polymer can be used for at least a portion of the base segment 100.

Preferably, when implanted in the left atrium, the outer surface 104 of the base segment is covered with at least a material M that conforms to and seals to the atrial wall in at least a circumferential region of the wall surrounding the left atrial appendage (LAA) within the left atrium so as to seal the LAA.

Figures 6 and 7 illustrate the lower surface 106 of the base segment occupying the exemplary plane B discussed above, representing the designated upper annular surface, although other designations and locations are possible, as also described herein. The prosthetic one-way valve 400 is generally aligned with the annulus to enable one-way fluid communication therethrough, and is positioned within the base segment 100 and is shown as being generally located on the exemplary plane B representing the designated location of the upper annular surface as discussed above. The prosthetic valve 400 includes at least one leaflet, preferably two leaflets 402, and, as shown in Figure 8, defines a one-way opening 404 through the base support lower surface 106 to facilitate fluid flow therethrough and subsequently into the annulus while preventing reverse flow. The prosthetic one-way valve 400 may include a valve support device, such as a central cylinder 406, which is open to fluid flow and is in fluid communication with atrial blood and the annulus when the one-way prosthetic valve is open. The central cylinder 406 is constructed to provide support and attachment to the valve leaflet(s) 402 , is open to the fluid flow received within the left atrium, and in some embodiments, is constructed to focus or concentrate the received fluid flow toward the valve leaflet(s) 402 .

9 , central cylinder 406 may include valve leaflet(s) 402 disposed at or near a lower surface 408 of central cylinder 406. Alternatively, valve leaflet(s) 402 may be disposed and operatively connected within central cylinder 406 at a location above lower surface 408, with an exemplary embodiment illustrated by dashed lines and 402′.

Alternatively, the apertures (e.g., openings 404 of FIG. 8 ) can be substantially aligned with the annulus and arranged along at least two designated points A within plane B or along a curved sheet C, and prosthetic leaflets attached thereto can be provided to facilitate one-way valve function. The valve support device (e.g., central cylinder 406 ), when present, includes a height H2 that can be less than, greater than, or equal to the height of the base segment 100 and a lower surface 408 . The central cylinder 406 will also include a diameter D3 that is less than the diameters of the lower and upper surfaces 106 , 104 of the base segment 100 .

Because the prosthetic one-way valve 400 (particularly its lower surface 408) is not permitted to extend below the designated upper surface of the annulus as defined herein, native valve function is preferably not eliminated or otherwise degraded, except in the rare circumstances described herein.

It should be appreciated that in certain embodiments, the central cylinder 406 and the valve leaflet(s) 402 supported therein can be constructed and positioned such that the lower surface 408 of the central cylinder 406 can extend below the lower surface 106 of the base segment when implanted. See FIG9A for an exemplary embodiment. Again, with this arrangement, the valve leaflet(s) 402 can be positioned anywhere along and within the central cylinder 406. However, in these embodiments, the central cylinder 406 (including its lower surface 408) is not positioned in a position that in any way infringes, impinges, or encroaches upon native leaflet function, so as to satisfy one of the inventive objectives of preserving native leaflet function to the greatest extent possible. In other words, in this embodiment, the lower surface 408 of the central cylinder 406 can be positioned along a designated upper annular surface as defined by at least two designated points and/or a corresponding plane B or curved sheet C as defined herein, while the lower surface 106 of the base segment 100 can be positioned slightly above the designated upper annular surface, or both the lower surface 106 of the base segment 100 and the lower surface 408 of the central cylinder 406 can be positioned on or above the designated upper annular surface.

Additionally, in addition to a simple cylindrical profile, the central cylinder 406 may alternatively include a variety of alternative leaflet connection structures and shapes, such as rectangular, elliptical, polygonal, tapered profiles, and other shapes that can be used while retaining the functionality described above. Each of these alternatives is within the scope of the present invention.

Turning now to the intermediate spring-like segment 200, the embodiment shown in Figures 6 and 7 includes a plurality of spring elements 202, such as, but certainly not limited to, springs. The spring elements 202 used within the segment 200 are defined herein to include any structure or device that can be inelastically compressed and used to store mechanical energy that generates a biasing force when the device is compressed. Thus, when the spring element 202 of this embodiment is elastically compressed or extended from its resting position, it exerts a reaction force that is roughly proportional to its change in length. Generally, the spring elements 202 of the segment 200 include a first end 204 and a second end 206, wherein the first end 204 of each spring element 202 is operatively connected to the base segment 200, and the second end 204 of each spring element 202 is operatively connected to the atrial dome 300. When implanted, each spring element 202 is preferably non-elastically compressed, so that the spring elements 200 each exert a force tending to separate the atrial dome 300 from the base segment 200, thereby seeking to increase the distance D3 therebetween to ultimately return the spring to its uncompressed and unstretched equilibrium position. Thus, when implanted, the distance D3 between the atrial dome 300 and the base segment 200 is less than the distance D3 between the atrial dome 300 and the base segment 200 when not implanted and expanded (and, in some embodiments, not implanted and deflated). These forces, in turn, are transmitted between the atrial dome 300 and the upper surface of the atrial chamber and the base segment 200 and the upper surface of the annulus and/or the floor of the atrial chamber, and, in some embodiments, against the wall tissue of the atrial chamber.

The spring elements 202 are further preferably implanted in a compressed state that maintains some compression of the spring elements 202 such that the natural installed and expanded state within the atrial chamber includes generally upward and downward (axial) biasing forces set by the plurality of spring elements 200 .

The spring element 202 may be an elastic or superelastic material such as a shape memory material, for example, nitinol, a polymer, etc. Alternatively, the spring element 202 may include a shock absorber configuration, mechanical or gas compression, or any structure that allows for inelastic compression to store energy, so as to provide a constant biasing force tending to separate the atrial dome 300 from the base segment 200, and the constant biasing force presses the atrial dome 300 and base segment 200 into the tissue of the atrial chamber when the spring element 202 is implanted in the inelastic compressed state.

The biasing force generated by the spring element, combined with the generally complementary structural fit between various aspects of the device 10 (e.g., the outer and lower surfaces 104, 106 of the base segment, and/or the atrial dome 300), and the contours of the atrial chamber (e.g., the upper annular surface, the atrial chamber floor, and/or the atrial chamber wall), allows the anchoring structure to remain in place within the left atrium without at least rotation or translation of the base segment 100. Furthermore, in various embodiments, the spring element 202 can, among other things, become at least partially endothelialized within the atrial wall tissue over time, thereby providing additional anchoring support. This arrangement also allows for substantially axial translation of the atrial dome 300 and base segment 100 relative to each other, and the spring element 202 will allow for some compliant bending of the intermediate spring-like segment 200 in multiple radial directions, thereby enabling the implanted prosthetic valve to move or conform to the natural movement of the heart.

Alternatively, as shown in FIG7 , a plurality of spring elements 200 may be provided in a combination (possibly alternating) wherein a rigid wire 208 having little or no expansion or contraction properties may be disposed between the base segment 100 (in certain embodiments, the upper surface 108 of the base segment 100) and the outer surface 302 (e.g., wire boundary) of the atrial dome 300. This configuration may provide an upward expansion force bias to the structure while also tending to prevent the atrial dome 300 from generally deflecting downward or compressing relative to the base segment 100. Alternatively, only a plurality of rigid wires 208 may be connected between the base segment 100 (in certain embodiments, the upper surface 108 of the base segment 100) and the outer surface 302 (e.g., wire boundary) of the atrial dome 300. These rigid wires 208 may also become endothelialized over time, with the atrial chamber tissue providing additional anchoring support.

This arrangement may also allow for secure anchoring within the left atrium while enabling some axial bending of the atrial dome 300 relative to the base segment 100 and bending compliance of the intermediate spring-like segment 200 to a lesser or more controlled extent than in embodiments with only spring members.

As shown, the second end of the spring element is operatively connected to the outer surface of the dome structure. The dome (e.g., an atrial dome) can be formed by a wire border having a certain diameter and connected to the second end of the spring element, and can include any closed geometric shape, such as a circle, an ellipse, a triangle, or a polygon. The dome can include a diameter or maximum distance D4 across the dome structure, which diameter D4 is preferably less than the diameter of the upper surface of the base.

One scenario may include a diameter or maximum distance across the dome structure that is equal to the diameter of a central cylinder disposed within the base support. In this case, a plurality of support wires or struts (whether rigid or spring-like, or a combination thereof arranged in a possibly alternating manner) may be operatively connected to the central cylinder and the wire boundary defining the dome structure in a generally vertically aligned manner to provide further axial force and/or support, thereby concentrating the axial expansion force in a relatively small area on the top surface of the chamber, but wherein the force is not concentrated on a single point. In contrast, in the case of an open structure, the axial expansion force is distributed around the outer surface of the dome structure. In addition, in some closed structure configurations, for example, where the dome interior material is non-compliant or rigid as in a molded dome, the axial expansion force is also distributed throughout the interior material itself, which in turn is in press contact with the chamber top. In the case where the dome is molded, a wire boundary may or may not be required. When not required, the necessary connection is made directly to the molded material.

The atrial dome 300 can further include an open structure, i.e., there is no inner material on the inner portion of the wire border, or as shown, can be closed, i.e., an inner material covers the inner portion of the wire border, for example, tissue, fabric, etc. The atrial dome 300 can include a flexible, compliant wire border, or can be rigid. In the case of a closed structure, the atrial dome 300 can further include a flexible, compliant wire border combined with a flexible inner material. Alternatively, in a closed structure, the dome can include a rigid, compliant wire border combined with a flexible inner material or a rigid inner material. Alternatively, the closed structure embodiment of the dome can include a molded part of the shape shown, or can include a circumferential lip surface extending downwardly from the dome surface. The molded embodiment provides additional axial deflection/compression protection for the device.

The spring element is shown in Figures 6 and 7 as generally conforming to the shape of the wall of the chamber, having a generally arched concave profile with a slightly inward angle α, and having a rigid wire member (when present) with a slightly inward angle α', which can be equal to or different from angle α. Alternatively, as shown in Figure 10, the spring element 202 and the rigid wire (when present) can be provided in shorter lengths to achieve an inward angled orientation of angle α between the upper surface of the base segment 100 and the outer surface of the atrial dome 300 (e.g., the wire boundary) to further maximize the atrial force transmission from the biasing spring element 202 and the pressure and friction fit of the device within the chamber. When the rigid wire is present, they can also be angled at angle α', which can be equal to angle α, or can be different from angle α. Typically in the structure of Figure 10, the angles α, α' will be more acute than the angles α, α' of the structures in Figures 6 and 7.

Additionally, the base segment 100 contacts or may extend to the upper annular surface and provides a radial expansion force to achieve an additional pressure and friction fit against the chamber surface.

FIG11 shows another alternative embodiment in which the spring element 202 and the stiffening wire (when present) employ a concentration of axial force in a relatively small area to maximize the pressure and friction fit achieved during expansion. Thus, the spring element 202 and the stiffening wire (when present) are oriented approximately 90 degrees to the base segment 100, which also includes the valve segment 400 as in the other embodiments. Thus, the axial force concentration is transmitted directly to the atrial dome 300 and distributed around it when the dome 300 is in an open configuration, and further distributed through the atrial dome 300 when the atrial dome is covered or tethered with a cross member (such as a strut), and particularly when the covering is a molded material. This axial force concentration is maximized when the support struts are angled in a substantially straight line from the base stent to the periphery of the atrial dome.

Figures 12 and 13 illustrate alternative anchoring structure 10 configurations, wherein a flexible and, in some embodiments, expandable mesh comprising an intermediate segment 200 is shown, which is connected to the upper surface of the base segment 100, replacing the aforementioned spring element or spring element arrangement having a rigid wire. As discussed above, a valve support 400 is operatively connected therein to support at least one prosthetic valve leaflet, the valve support 400 being shown as being operatively connected within the base segment 100. The atrial dome structure 300 described above can be operatively connected to the wire mesh and have the geometries and materials discussed with respect to the various embodiments herein. As described above, and as shown in Figure 12, the atrial dome 300 can include a covered surface, or as shown in Figure 13, the atrial dome can include an open structure defined by an outer surface 302 or a boundary (e.g., a wire boundary) that, when the expandable structure is expanded and implanted, will at least partially be operatively connected to the upper surface or top of the heart chamber. The border (e.g., wire border 302) can serve as an attachment point for the flexible and expandable mesh material, particularly in the case of an open atrial dome embodiment. Alternatively, as described above, the atrial dome 300 can include a covered area. Still alternatively, the atrial dome 300 can include a separate structure attached to and positioned on top of the wire mesh segment, such that there are no openings or cutouts on top of the wire mesh segment.

In addition, FIG13 shows the spring element 202 and/or the rigid wire element 208 discussed above in conjunction with the mesh of FIG12 (the mesh is not shown in FIG13 ). In this connection, the spring element 202 and/or the rigid wire element 208 can be disposed on the inner surface of the mesh and/or on the outer surface of the mesh. Alternatively, the spring element and/or the rigid wire can be integrated into or woven through the mesh structure and, as described above, connected between the base segment and the atrial dome.

FIG12 also shows an alternative structure that helps transmit axial forces to the atrial dome 300 and distribute them around the atrial dome 300 when the dome 300 is in an open configuration, and also distributes them through the atrial dome 300 when the atrial dome is covered, and particularly when the covering is a molded material. Thus, in this alternative embodiment, struts 222 are shown in phantom to provide direct transmission of axial forces between the base segment 100 and the atrial dome 300 to assist in anchoring. The struts 222 can be rigid or can include some axial compliance and/or radial flexibility.

Furthermore, the rigid and/or spring-like support elements discussed above, which, when present, can be operatively connected between the central cylinder and the dome, can be included with the wire mesh configuration of Figure 12. Alternatively still, in embodiments that do not include a dome structure, the rigid and/or spring-like support elements (if present) can directly connect the central cylinder to the wire mesh in a generally vertical orientation, as viewed in the front or side views discussed above.

In each of the embodiments described herein, the expanded and implanted structure is positioned within the heart chamber at a location that does not adversely interfere with or impair the function of the native valve leaflets. Positioning and placement have been described above. Generally, the present invention contemplates placing and/or positioning the prosthetic valve structure at or above the native leaflet inflection point FP. Turning now to Figures 14-15, there is shown an alternative embodiment of an exemplary form of providing a device in which a prosthetic valve segment 400 including an exemplary valve supporting central cylinder 406 and (multiple) prosthetic leaflets 402 is positioned and/or placed above an annular plane of an exemplary left atrium (plane B as shown), and in which there is no anchoring, engagement or interaction of the implant and expansion device with the inner annulus IA, the native leaflets or the left ventricle.

Thus, FIG. 14 illustrates an exemplary embodiment in which the device is expanded and implanted in the left atrium, wherein the base segment 100 includes an outer segment 150 transitioning from the lower outer surface 106 of the base segment 100 to a generally central raised or elevated portion 152. A central cylinder 406 is shown operatively attached to at least a portion of the raised or elevated portion, as an exemplary form of a valve support in which prosthetic one-way valve leaflets are operatively attached. Central cylinder 406 is described above in conjunction with FIG. 9 . Thus, the raised or elevated portion 152 of the lower surface of the base segment 100 is spaced above the outer segment of the lower surface of the base segment and defines an aperture A therethrough, with the central cylinder 152 generally aligned with aperture A. As with the other embodiments, an intermediate spring-like segment 200 is provided for operative attachment to the base segment and atrial dome 300. The middle section 200 is shown as having an exemplary mesh configuration, but other elements and/or structures described herein may be used. As with all middle sections 200 described herein, the section 200 is open to blood flow from the left and right upper pulmonary veins (LUP, RUP) and the left and right lower pulmonary veins (LLP, RLP), and the base section may be covered with a material capable of sealing the left atrial appendage.

The central raised portion 152 can be located or can be at least partially disposed on plane B', which is spaced or spaced a distance d above plane B and, in turn, spaced at least a distance d above the exemplary annulus and mitral valve leaflets MV of the left atrium. Plane B represents an anatomical feature in the left atrium as known in the art as an annular plane. Thus, in this embodiment, the lower surface of the exemplary central cylinder is positioned above or spaced a distance d above the annular plane represented by plane B. Thus, the lower surface of the exemplary central cylinder valve support is spaced above the native valve leaflets, and in particular, above the bend point FP of the native valve leaflets discussed above. This arrangement and spacing ensures that the device does not deleteriously interfere with or engage the normal function of the native valve leaflets.

Additionally, the prosthetic valve leaflets within the exemplary central cylindrical valve support 406 are also spaced above the annular plane represented by plane B. In certain embodiments, the prosthetic valve leaflets 402 can be generally attached at the lower surface 408 of the exemplary central cylindrical valve support 406 such that the spacing between annular plane B and the attachment point of the prosthetic valve leaflets within the valve support 406 is approximately the same distance as the spacing between the lower surface of the exemplary central cylindrical valve support 406 and annular plane B.

In other embodiments, and as discussed above, the prosthetic valve leaflets 402 can be operatively attached at any point within the lumen of the exemplary central cylindrical valve support 406, and thus can be attached at a point within the central cylinder 406 that is above the lower surface 408 of the exemplary central cylinder described in conjunction with FIG 9. Thus, in this case, the spacing between the annular plane B and the point of attachment of the prosthetic valve leaflets will be greater than the spacing between the annular plane B and the lower surface 408 of the exemplary central cylindrical valve support 406.

FIG14 further provides rounded transitions or inflection points 1, 2 on a first side of the central raised portion and two rounded transitions or inflection points 3, 4 on a second side of the central raised portion, thereby defining a transition from the lower surface of the base support upward to the central raised or elevated portion and then back downward to the lower surface of the base support. Any of the transition points 1, 2, 3, 4 can be formed with a larger or smaller radius than shown, with the rounded corners of transition point 1 being approximately equal to the rounded corners of transition points 2, 3, and/or 4. Alternatively, the rounded corners of transition point 1 are less than or greater than the rounded corners of transition points 2, 3, or 4. Additionally, the transition points can include one or more sharp corners, such that any one of transition points 1, 2, 3, and/or 4 can include either a sharp or rounded transition, or a combination of sharp and rounded transition points 1, 2 can be present.

Thus, an open sub-prosthetic valve region OVR is formed between the bottom surface 408 of the exemplary central cylinder 406 and the annular plane represented by plane B. The width of the open sub-prosthetic valve region preferably corresponds to the distance from inflection point 1 to inflection point 4 and/or the distance from inflection point 2 to inflection point 3, but the width may vary.

Generally, it is preferred that the lower surface 408 of the exemplary central cylindrical valve support 406 be positioned at the transition points 2, 3 or at the top of the raised valve segment 152. However, it is within the scope of the present invention to position the lower surface of the exemplary central cylindrical valve support 406 below the transition points 2, 3 but above the annular plane B while still maintaining the functionality of the embodiment including the raised valve segment 400.

An alternative embodiment of a valve support may include a support structure, such as a support ring 154, comprising a relatively rigid material (e.g., wire or other similar material) to which the prosthetic valve leaflets 402 may be attached within a raised region or portion 152 of the base segment 100. This embodiment is shown in FIG15 , in which the mid-segment and atrial dome are omitted.

Still alternatively, an outer section of the lower base section can define an aperture that is generally coextensive with the annulus at or near the location of annular plane B. As shown in Figures 6-7 and 10-13, the central cylinder 406 can be operatively attached to the base section 100 at or near the aperture, with the prosthetic valve leaflets 402 operatively attached within the central cylinder, as described above. In the preferred embodiment depicted in Figure 9, the attachment point of the prosthetic valve leaflets 402 within the central cylinder 406 can be located above and spaced above annular plane B, and thus above the attachment point of the exemplary central cylindrical valve support to the base section, thereby providing elevation of the valve leaflets relative to the annular plane and/or the bend point FP of the native leaflets.

In each of these embodiments, the structure of the device itself, when expanded and implanted, is constrained to the boundaries of a single heart chamber (e.g., but not limited to, the left atrium). In this way, these embodiments maintain any remaining native valve and/or leaflet function without adversely interfering with that function. Furthermore, when the loss of native valve and/or leaflet function reaches the point of total failure, the expanded and implanted device with the raised valve segment assumes the function of a complete replacement of the now-totally failed native valve.

Raised valve embodiments having a valve support (eg, central cylinder 406 and valve leaflets 402 disposed therein) or a support ring 154 having valve leaflets 402 attached thereto may be used in conjunction with any of the embodiments described above.

In the case of a patient with a partially functional, and therefore partially dysfunctional or malfunctioning, native valve, the use of each of the embodiments described herein provides a novel therapeutic outcome. Thus, the expanded implantation of one of the described embodiments in a patient will allow for the initial replenishment or enhancement of the partially dysfunctional or malfunctioning native valve to a normal level of function or near normal level of function, that is, to prevent regurgitation into the subject's heart chambers. In all cases, the implanted prosthetic valve works to prevent regurgitation from the native valve into the subject's chambers by allowing the native valve to continue functioning, but some regurgitation is prevented by the partially functional native valve and leaflets.

Over time, native valve function may deteriorate, thereby leading to increasing levels of regurgitant flow through the native leaflets. As this progressive regurgitant process progresses, the expanded and implanted prosthetic valve device works to prevent the steadily increasing regurgitant flow or jet, thereby maintaining normal full function by preventing the regurgitant flow or jet from entering the subject's heart chambers.

Ultimately, native valve function may be almost completely lost. In this case, the implanted prosthetic valve device described herein would take over complete replacement responsibility, thereby preventing all pressurized backflow from the antegradely positioned heart chamber to the implanted prosthetic heart valve.

As discussed, an exemplary chamber for implantation of the devices and methods described herein is the left atrium, wherein the at least partially functional native valve comprises the mitral valve, and the antegrade chamber comprises the left ventricle.

In addition, as described in certain embodiments herein, a prolapsed native valve leaflet can be substantially prevented from abnormally prolapsing by a portion of the device structure to help the native leaflet retain normal function, thereby extending the time of at least partial function and preventing a moment of almost complete loss of function.

Each of the embodiments discussed and illustrated herein may further include an expansion and implant structure that does not extend into the lumen of the pulmonary artery or otherwise engage the pulmonary artery.

Thus, generally, the devices described herein will re-establish nearly complete valve function by preventing regurgitant flow from reaching the exemplary left atrium and gradually increasing augmentation or supplementation of the slowly deteriorating native valve and/or leaflets while preserving residual native valve function until nearly complete replacement function is achieved.

The description of the present invention and its application set forth herein is illustrative and is not intended to limit the scope of the present invention. The features of each embodiment can be combined with other embodiments within the concept of the present invention. Variations and modifications of the embodiments disclosed herein are possible, and those skilled in the art will understand the actual alternatives and equivalents of the various elements of the embodiments when studying this patent document. Without departing from the scope and spirit of the present invention, these and other variations and modifications may be made to the embodiments disclosed herein.

Claims (14)

1. A device for expanding an implanted cardiac chamber, in fluid communication with a valve annulus comprising an annular plane and a native valve having leaflets, said device comprising: A base segment includes a lower portion defining a lower surface, the lower surface being at least partially disposed on the annular plane, the lower portion including a protrusion spaced apart above the lower surface of the base segment and the annular plane; The atrial dome segment engages with pressure and friction at the top of the chamber during device expansion and implantation; The middle segment, operatively attached to the base segment and the atrial dome segment, is operatively connected to the base frame and the top segment; and The device includes a central cylindrical valve support with a lower surface, the central cylindrical valve support being operatively attached to a protrusion of the base segment, and including at least one prosthetic valve leaflet operatively attached thereto, the lower surface of the central cylindrical valve support being spaced apart above the lower surface of the base segment and the annular plane. 2. The device according to claim 1, further comprising: the at least one prosthetic valve leaflet being attached within the central cylindrical valve support at the lower surface of the central cylindrical valve support. 3. The apparatus of claim 1, further comprising: the at least one prosthetic valve leaflet being attached within the central cylindrical valve support at a position above the lower surface of the central cylindrical valve support. 4. The device of claim 1, wherein the cardiac chamber comprises a left atrium, and the native valve comprises a mitral valve containing native leaflets. 5. The device of claim 1, further comprising that the dilation and implantation device does not include a structure engaging with the native valve leaflet. 6. The device of claim 4, further comprising, wherein the dilation and implantation device does not include a structure for engaging with a native mitral valve comprising a native leaflet. 7. The device of claim 4, further comprising that the dilation and implantation device does not include structures present in the left ventricle. 8. The device of claim 4, further comprising that the dilation and implantation device does not include structures present within the pulmonary artery. 9. A device for expanding an implanted cardiac chamber, in fluid communication with a valve annulus comprising an annular plane and a native valve having leaflets, said device comprising: The base section includes a lower surface at least partially disposed on the annular plane, the lower surface defining a hole positioned generally around the petal annulus; The top section engages with pressure and friction at the top of the chamber during expansion and implantation of the device; A middle section, operatively attached to the base section and the top section, and operatively connected to the base frame and the top section; and The device includes a central cylindrical valve support with a lower surface, the lower surface of which is operatively connected to a hole-defined portion of the lower surface of the base segment. The central cylindrical valve support further includes at least one prosthetic valve leaflet operatively attached thereto at a position above the lower surface of the central cylindrical valve support, wherein the lower surface of the central cylindrical valve support does not extend below the annular plane. 10. The apparatus of claim 9, further comprising: the at least one prosthetic valve leaflet being attached within the central cylindrical valve support at the lower surface of the central cylindrical valve support. 11. The device of claim 9, wherein the cardiac chamber comprises the left atrium, and the native valve comprises the mitral valve. 12. The apparatus of claim 11, further comprising that the dilation and implantation device does not include structures present in the left ventricle. 13. The device of claim 11, further comprising, wherein the dilation and implantation device does not include a structure engaging with the native valve leaflet. 14. The device of claim 11, further comprising that the dilation and implantation device does not include structures present within the pulmonary artery.