FIELD OF THE DISCLOSURE

Embodiments of the present disclosure are directed to systems, methods, and devices for cardiac valve replacement in mammalian hearts.

BACKGROUND OF THE DISCLOSURE

Conventional approaches for cardiac valve replacement require the cutting of a relatively large opening in the patient's sternum (“sternotomy”) or thoracic cavity (“thoracotomy”) in order to allow the surgeon to access the patient's heart. Additionally, these approaches require arrest of the patient's heart and a cardiopulmonary bypass (i.e., use of a heart-lung bypass machine to oxygenate and circulate the patient's blood). In recent years, efforts have been made to establish a Jess invasive cardiac valve replacement procedure, by delivering and implanting a cardiac replacement valve via a catheter percutaneously (i.e., through the skin) via either a transvascular approach—delivering the new valve through the femoral artery, or by transapical route, where the replacement valve is delivered between ribs and directly through the wall of the heart to the implantation site.

While Jess invasive and arguably less complicated, percutaneous heart valve replacement therapies (PHVT) still have various shortcomings, including the inability for a surgeon to ensure proper positioning and stability of the replacement valve within the patient's body. Specifically, if the replacement valve is not placed in the proper position relative to the implantation site, it can lead to poor functioning of the valve. For example, in an aortic valve replacement, if the replacement valve is placed too high, it can lead to valve regurgitation, instability, valve prolapse and/or coronary occlusion. If the valve is placed too low, it can also lead to regurgitation and mitral valve interaction.

To address such risks, recapture procedures and systems have been developed. For example, such a system is disclosed in U.S. publication no. 20050137688 and U.S. Pat. No. 5,957,949, each disclosure of which is herein incorporated by reference. While such systems may address the problem of improper placement, they are somewhat complicated, requiring the use of wires which are removable attached to an end of the stent to pull the stent back into the delivery catheter.

Throughout this description, including the foregoing description of related art, any and all publicly available documents described herein, including any and all U.S. patents, are specifically incorporated by reference herein in their entirety. The foregoing description of related art is not intended in any way as an admission that any of the documents described therein, including pending United States patent applications, are prior art to embodiments according to the present disclosure. Moreover, the description herein of any disadvantages associated with the described products, methods, and/or apparatus, is not intended to limit inventions disclosed herein. Indeed, aspects of the disclosed embodiments may include certain features of the described products, methods, and/or apparatus without suffering from their described disadvantages.

SUMMARY OF THE DISCLOSURE

In some embodiments, a replacement valve for use within a human body is provided, where the replacement valve includes a valve component and a stent component (the replacement valve also being referred to as a valved-stentor a stent valve, and may be used interchangeably with replacement valve throughout the disclosure). The stent component defines a first (e.g., proximal) end and a second (e.g., distal) end and may include a plurality of stent section, and in some embodiments, at least four stent sections. The proximal end P of the stent component may be described as the end of the stent component/replacement valve which ultimately is positioned adjacent and/or within the left ventricle. Alternatively, the proximal end P of the stent component may be described as the end having anchoring elements for attachment to the delivery catheter (e.g., attachment end in a transapical delivery system). The distal end D of the stent component may be described as the end of the replacement valve/stent component which ultimately is positioned adjacent and/or near the ascending aorta, when, for example, the delivery catheter is advanced toward/into the ascending aorta in a transapical delivery system. According to preferred embodiments of the disclosure, the replacement valves according to at least some embodiments are released distal-to-proximal, that is, the end of the stent (replacement valve) which ultimately is positioned within/near/adjacent the aorta is released first, and the end of the stent (replacement valve) which ultimate is positioned within/near/adjacent the ventricle is released last. Such a delivery, according to preferred embodiments, is via a transapical approach, or through the heart muscle (as opposed to being delivered transvascularly). While preferred embodiments disclosed herein are described as being delivered through a direct heart access approach (e.g., transapical approach using transapical/direct access delivery systems), some embodiments of the present invention may be delivered transvascularly.

The first stent section may define an at least partly conical body and the first end of the stent component. The conical body of the first stent section may slope outwardly in the direction of the first end. In some embodiments, the first stent section may include at least one attachment element for removable attachment to a delivery device.

The second stent section may be in communication with the first stent section and may define an at least partly conical body. The conical body of the second stent section may slope outwardly in the direction of the second end.

The third stent section may be in communication with the second stent section and may define an at least partially cylindrical body. The third stent section may be configured to house at least a portion of the valve component. The third stent section may include a plurality of arches for fixation to a corresponding plurality of commissures of the valve component.

The fourth stent section may be in communication with the third stent section and may define the second end. The fourth stent section may further define an at least partly conical body, which may slope outwardly in the direction of the second end. The fourth stent section may include a plurality of arches larger than, but aligned with, the plurality of arches included in the third stent section.

The four stent sections may be formed, for example, by laser cutting a tube or single sheet of material (e.g., nitinol). For example, the stent may be cut from a tube and then step-by-step expanded up to its final diameter by heat treatment on a mandrel. As another example, the stent may be cut from a single sheet of material, and then subsequently rolled and welded to the desired diameter.

In some embodiments of the present disclosure, a stent component may be provided that includes a central, longitudinal axis and at least one attachment element for removable attachment to a delivery device. The at least one attachment element may be formed generally in the shape of a hook extending inwardly towards the central, longitudinal axis. The delivery device may include a stent holder comprising a groove for receiving the attachment element of the stent component, wherein release of the stent-valve from the stent holder may be facilitated by rotation of the stent holder relative to the attachment element.

In still other embodiments of the present disclosure, a replacement valve for use within a human body is provided that includes a valve component, a stent component for housing the valve component, and at least two skirts (e.g., polyester (PET) skirts). An inner skirt may be provided that covers at least a portion (e.g., all) of an outer surface of the valve component, where the inner skirt may be sutured to at least the inflow tract of the valve component and to an inner surface of the stent. An outer skirt may also be provided that is sutured onto an outer surface of the stent.

Some embodiments of the present disclosure provide a cardiac stent-valve delivery system that includes an inner assembly and an outer assembly. The inner assembly may include a guide wire lumen (e.g., polymeric tubing) and a stent holder for removable attachment to a stent-valve. The outer assembly may include a sheath. The imler member and the outer member may be co-axially positioned and slidable relative to one another in order to transition from a closed position to an open position, such that in the closed position the sheath encompasses the stent-valve still attached to the stent holder and thus constrains expansion of the stent-valve. In the open position, the outer sheath may not constrain expansion of the stent-valve and thus the stent-valve may detach from the stent holder and expand to a fully expanded configuration.

In some embodiments, the inner assembly of the delivery device may include a fluoroscopic marker fixed to the guide wire lumen distal of the stent holder.

In some embodiments, the diameter of the outer assembly of the delivery device varies over its longitudinal axis.

In still other embodiments, the delivery system comprises a rigid (e.g., stainless steel) shaft in communication with a proximal end of the guide wire lumen.

In some embodiments, the delivery system comprises a luer c01mector in communication with the rigid shaft.

In some embodiments of the present disclosure, a method is provided for replacing an aortic valve within a human body. A stent-valve may be covered with a sheath in order to maintain the stent-valve in a collapsed configuration. The stent-valve may then may be inserted in the collapsed configuration into the human body without contacting the ascending aorta or aortic arch. The stent-valve may be partially expanded by sliding the sheath towards the left ventricle of the heart. This sliding of the sheath towards the left ventricle may cause expansion of a distal end of the stent-valve while the proximal end of the stent-valve remains constrained by the sheath. The sheath may be further slid towards the left ventricle of the heart in order to cause full expansion of the stent-valve. In some embodiments, the stent-valve may be recaptured prior to its full expansion by sliding the sheath in the opposite direction.

In some embodiments, a method for cardiac valve replacement is provided that includes releasing a distal end of a stent-valve from a sheath, where the distal end includes a radiopaque marker positioned thereon. The stent-valve is rotated, if necessary, to orient the stent-valve appropriately with respect to the coronary arteries (e.g., to prevent the commissures from facing the coronary arteries). Arches of the stent-valve are released from the sheath, in order to cause the arches to contact the aorta. A first conical crown of the stent-valve is released from the sheath, in order to cause the first conical crown to contact the native valve leaflets. A second crown of the stent-valve is released from the sheath, in order to cause the second crown to contact an annulus/inflow tract. The second crown may be the proximal section of the stent-valve such that releasing the second crown causes the stent-valve to be fully released from the sheath.

