Transcatheter valve leaflet replacement device, delivery, guidance and fixation system and method

Abstract

A transcatheter heart valve leaflet replacement system includes a valve prosthesis and a multi-stage, multi-lumen (MSML) heart valve delivery and implantation system for guiding and implanting the prosthesis into the native valve annulus. The prosthesis includes a stent frame including an upper atrial flared portion and a lower ventricular portion, a plurality of artificial valve leaflets, and at least one lining skirt. The prosthesis is configurable or otherwise adjustable in size to be selectively expanded to an operational size and position when fitted within the MSML delivery and implantation system and subsequently deployed within the valve annulus. A portion of the prosthesis may be configured to couple with a dual guide and fixation (DGF) member to guide and fix the prosthesis into the valve annulus. In one embodiment, the MSML delivery and implantation system includes a primary docking system, a DGF member delivery system, and a valve housing, positioning, and locking system.

Description

[Technical Field]

[0001] This application relates generally to heart valve replacement systems and transcatheter implantation of prosthetic heart valves, for example, to replace diseased mitral and / or tricuspid valves in humans or animals. More particularly, embodiments of the subject matter relate to tissue-based valve leaflet replacement systems and methods for operatively delivering and securing replacement valve leaflets to their target positions.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of co-pending U.S. Provisional Application No. 62 / 988,253, filed March 11, 2020, and is a continuation-in-part of co-pending U.S. Provisional Application No. 15 / 453,518, filed March 8, 2017, which claims the benefit of U.S. Provisional Application Nos. 62 / 305,204, filed March 8, 2016, 62 / 413,693, filed October 27, 2016, and 62 / 427,551, filed November 29, 2016. This application extends the scope of the present invention and is a continuation-in-part of co-pending application Ser. No. 17 / 121,615, filed December 14, 2020, which is a continuation-in-part of co-pending application Ser. No. PCT / US2019 / 037476, filed June 17, 2019, which claims the benefit of U.S. Provisional Application Ser. No. 62 / 685,378, filed June 15, 2018, the entire disclosures of which, including the specification and drawings, are incorporated herein by reference in their entirety. [Background technology]

[0003] The mitral valve (MV) is located between the left atrium (LA) and left ventricle (LV) of the human heart and typically consists of the mitral annulus (MA), two valve leaflets, chordae tendineae ("chordae"), two papillary muscles, and left ventricular myocardium. The mitral annulus is subdivided into an anterior and a posterior portion.

[0004] When the mitral valve is closed, the anterior and posterior leaflets of the mitral valve are in close contact, forming a single area of apposition. As those skilled in the art will appreciate, normal MV function involves a proper balance of forces, with each of its components working in unison during the cardiac cycle. Pathological changes affecting any of the MV components, such as ruptured chordae, annular dilation, papillary muscle displacement, leaflet calcification, and myxomatous disease, can lead to altered MV function and potentially cause mitral regurgitation (MR).

[0005] Mitral regurgitation is a malfunction of the MV that causes abnormal leakage of blood from the LV back into the left atrium during systole (ie, the ejection phase of the cardiac cycle when blood moves from the LV into the aorta).

[0006] Current treatments for MV disease include surgical repair and replacement of the MV, and more recently, transcatheter repair and replacement of the MV.

[0007] Notable challenges to effective MV replacement devices generally include operational delivery challenges, positioning and fixation challenges, sealing and paravalvular leak challenges, and hemodynamic function challenges such as left ventricular outflow tract (LVOT) obstruction.

[0008] Regarding the operational delivery challenges mentioned above, because conventional mitral valve prostheses are larger than conventional aortic prostheses, it is more difficult to collapse and compress the larger mitral valve prosthesis into a catheter for deployment and retrieval by either conventional transapical or transfemoral delivery techniques.

[0009] Turning to the challenges of positioning and implantation, instability and migration are the most prominent obstacles, as the mitral valve is subjected to high repetitive loads during the cardiac cycle due to high transvalvular pressure gradients and the dynamic motion of the beating heart.

[0010] Regarding sealing and paravalvular leakage, the mitral annulus is large, so a good fit between the native annulus and the prosthetic valve is desirable to minimize paravalvular leakage. Prosthetic mitral valves typically have a large, overhanging atrial section or flare, which can prevent leakage. However, the problem is that a large valve size is required at the ventricular level to ensure the prosthesis is securely attached to the native MV. Traditionally, prosthetic mitral valves are smaller than the affected native valve, and additional material is added around the prosthesis to compensate for the large native annulus. Unfortunately, adding additional material to the prosthetic valve increases the size of the delivery system, potentially leading to valve thrombosis.

[0011] Some current transcatheter delivery systems utilize a folding structure in the replacement valve stent to capture and grip the native valve leaflets and annulus to secure the replacement valve. Such methods often result in device detachment due to insufficient interaction forces between the implant and the native tissue, or excessive interaction forces that cause damage (e.g., tearing) and / or remodeling (e.g., stretching, remodeling) of the native tissue, leading to implant instability and / or migration.

[0012] Finally, with regard to maintaining hemodynamic function, the operating position of conventionally large prosthetic mitral valve devices, as described above, must not obstruct the LVOT at the anterior portion of the mitral annulus and must not interfere with the native aortic valve and / or associated structures of the mitral valve.

[0013] Therefore, it would be beneficial to have a heart valve leaflet replacement device and delivery / implantation system that does not suffer from the shortcomings and deficiencies of current systems. It is desirable to secure a prosthetic mitral valve replacement system to the native mitral valve annulus. It is also desirable to improve positioning of the prosthetic mitral valve, avoid LVOT obstruction, and prevent blood leakage between the prosthetic mitral valve and the native MV. Furthermore, other desirable features and characteristics will become apparent from the following detailed description and the appended claims, when considered in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the Invention

[0014] Described herein is a heart valve leaflet replacement system that includes a heart valve leaflet replacement device (e.g., a prosthetic mitral valve replacement device) and a multi-stage, multi-lumen (MSML) heart valve delivery and implantation system for guiding and securing the heart valve leaflet replacement device to one or more native valve annuli. In one aspect, the MSML heart valve delivery and implantation system can be configured to guide and secure a mitral valve replacement device to a native mitral valve annulus. In another aspect, the MSML heart valve delivery and implantation system can be configured to guide and secure a prosthetic tricuspid valve replacement device to a native tricuspid valve annulus. For clarity, the present disclosure focuses on the delivery and implantation of leaflet replacement devices for the treatment of functional and degenerative mitral valve regurgitation, but it is contemplated that the leaflet replacement device, MSML delivery and implantation system, and related methods can be used or otherwise configured to treat other valvular diseases and replace other valves in the human heart, or in other mammals or animals suffering from valve defects, as well.

[0015] In one aspect, a heart valve leaflet replacement system can include a heart valve leaflet replacement device or prosthesis that can be configured or otherwise adjusted to fit within an MSML delivery and implantation system and subsequently selectively expand to an operational size and position upon removal from the MSML delivery and implantation system within the heart. In a further aspect, at least a portion of the prosthesis can include a stent having an upper atrial flaring portion and a lower ventricular portion. In one aspect, the atrial flaring portion can be configured to couple with a plurality of dual guide and fixation (DGF) members to guide and secure the stent onto the valve annulus, thereby helping to prevent paravalvular leakage and dislodgement of the prosthesis after implantation. The lower ventricular portion of the prosthesis can displace a portion of the native valve leaflets out of the blood flow path and accommodate at least one prosthetic leaflet. In another aspect, a heart valve leaflet replacement device can include a lining skirt that can be coupled to at least a portion of the inner and / or outer surface of the stent. Optionally, the outer surface of the stent can be configured with additional skirt material to prevent paravalvular leakage. In one exemplary embodiment, at least one prosthetic valve leaflet can be attached to at least a portion of the inner lumen of the stent and / or the exterior of the stent, which can function in place of at least one native valve leaflet to restore normal valve function, e.g., to prevent mitral regurgitation.

[0016] In an exemplary embodiment, the MSML delivery system can be configured to implant a heart valve leaflet replacement system in a two-step procedure: In step 1, multiple DGF members are implanted into the native annulus of the diseased valve; and in step 2, a prosthetic heart valve leaflet replacement device is implanted and secured in place over the implanted DGF members.

[0017] As will be apparent to those skilled in the art, a variety of other prosthetic valve replacement devices, whether half valves or full valves, circular or non-circular, can be delivered and implanted using the MSML delivery methods described in this disclosure.

[0018] In one aspect, delivery of the prosthesis can be performed using any desired delivery access approach, such as, for example, but not limited to, minimally invasive surgery, transseptal, or transatrial approaches. In one exemplary aspect, a transseptal approach can include creating an opening in the internal jugular or femoral vein for subsequent minimally invasive delivery of the heart valve leaflet replacement device or portion of the prosthetic device through the superior or inferior vena cava, which drains into the right atrium of the heart. In this exemplary aspect, the access path of the transseptal approach crosses the atrial septum of the heart, and once achieved, components of the heart valve leaflet replacement device can be operatively positioned within the left atrium, native mitral valve, and left ventricle.

[0019] In one aspect, the MSML delivery implantation system can comprise a primary docking / guiding system, a DGF component delivery system, and a valve housing positioning and locking (VHPL) system.

[0020] In one exemplary embodiment, the VHPL can include a guide sheath, multiple locking catheters, a stent holder sheath, and a valve chamber sheath.

[0021] In one aspect, it is contemplated that a primary docking sheath may be placed within the access pathway to allow the desired components of the heart valve leaflet replacement system to be operably positioned within the left atrium without complications.

[0022] In one embodiment, one component of the heart valve leaflet replacement device can include a DGF member that is operably positioned and implanted at a desired location in the native mitral valve annulus prior to delivery of the prosthesis. In this embodiment, the DGF member can guide the subsequent accurate positioning and fixation of the prosthesis. In a further embodiment, multiple DGF members can help prevent blood leakage between the operably positioned prosthesis and the native mitral valve annulus. In one embodiment, the DGF member can be configured to have a removable component and a permanent component, where the removable component helps guide the heart valve leaflet replacement device into an operative position and can be removed from the patient's body after fixating the prosthesis, while the permanent component can remain in the patient's body, fixing the heart valve leaflet replacement device to the native valve annulus.

[0023] In an exemplary embodiment, the DGF member can include multiple sections, such as a head member, a body member, and a tail member. In one embodiment, the DGF head member can be operably inserted and implanted within annular tissue. In one embodiment, the DGF body member can be configured with a DGF locking member for securing the heart valve leaflet replacement device to the native mitral valve annulus. In another embodiment, the DGF body member can be configured to be engaged with a catheter, implant the DGF head member into tissue, and then detached from the catheter, leaving the entire DGF member permanently implanted in the valve annulus. The DGF member is designed to be removable and repositionable. In one embodiment, the DGF tail member can be configured as a flexible component extending from the proximal portion of the DGF body to the proximal end of the MSML system. Optionally, the DGF tail can be configured to be selectively removable so that it can be removed from the body upon completion of the heart valve leaflet replacement system implantation procedure.

[0024] Those skilled in the art will appreciate that during surgery, because the patient's heart is beating and the annular tissue is moving, it may be difficult to 1) engage with the annular tissue and 2) maintain proper placement of the DGF delivery system during implantation of the DGF element. Under such conditions, a stabilizing member may be considered necessary. In this embodiment, the DGF head element may be configured with a stabilizing member, such as a concentric needle within the DGF head element, that acts to stabilize the DGF element and the DGF element delivery mechanism during implantation of the DGF element. In one embodiment, the stabilizing member may be configured with other mechanisms that can engage and / or disengage with tissue, such as vacuum suction, clamp and release, or other mechanisms that rely on changes induced by electromagnetic or thermal fields.

[0025] In one aspect, the DGF body member can be configured with a prosthetic valve fixation mechanism including a plurality of DGF locking members, which can be configured to engage with the prosthetic valve to secure the prosthetic valve in an operative position.

[0026] In an exemplary embodiment, the DGF locking member can be configured to attach to the DGF body member via a flexible component.

[0027] The DGF locking member may be configured to engage with the DGF tail member.

[0028] In one embodiment, the prosthesis can be configured to engage with the DGF locking member through multiple through-holes in the atrial flaring portion of the stent frame. In this embodiment, the DGF tail member can be a tether, with one end attached to the DGF body member and the other end configured to extend from the body. The tether can then be threaded through the holes in the atrial flaring portion of the stent, thereby delivering the prosthesis onto the DGF tail member and accurately delivering the atrial flaring portion of the stent to the DGF body member embedded in the valve annulus.

[0029] In one aspect, the placement of such DGF elements is not random: the spacing of the DGF elements on the annulus should closely match the spacing of the through-holes in the prosthetic stent to ensure accurate positioning and placement of the prosthesis within the posterior annulus.

[0030] In another embodiment, two sets of DGF members can be deployed separately. In this embodiment, the first set of DGF members can be implanted near the commissures of the native valve and midway through the posterior annulus. This set of DGF members guides the precise positioning and deployment of the prosthesis. After deployment of the valve, the second set of DGF members can be implanted directly on top of the deployed prosthesis. In another embodiment, the second set of DGF members can be deployed on top of the flared section of the prosthetic stent. It will be appreciated that the additional DGF members implanted in the posterior annulus can reduce the gap between the prosthetic and native annulus, thereby preventing paravalvular leakage and ultimately prosthetic valve detachment.

[0031] In one aspect, the DGF locking element can be configured to be selectively compressed to a diameter smaller than the diameter of the hole in the atrial flaring portion of the stent to allow it to pass through the hole, and then selectively re-expanded to its original size larger than the diameter of the hole to prevent the DGF locking element from migrating backward through the hole in the flaring portion of the stent.

[0032] In one exemplary embodiment, the DGF locking element can be configured with multiple radially compressible legs, for example, forming a cone shape with a proximal tip having a smaller diameter than the atrial flaring hole of the stent and a distal base of the cone shape having a larger diameter than the atrial flaring hole of the stent. During operation, tension can be applied to the DGF tail to retract the proximal tip of the DGF locking element into the atrial flaring hole of the stent, and when the locking element legs contact the edge of the hole, they radially compress, allowing the DGF locking element to be fully retracted through the hole. Once the locking element has fully passed through the stent, the DGF locking element legs can be re-expanded to their full size to prevent the DGF locking element from migrating backward through the atrial flaring hole.

[0033] In one embodiment, the VHPL system can include a guide sheath that fits within the lumen of the docking sheath and can house all of the other VHPL system components. In one exemplary embodiment, the guide sheath is configured with a separator at its distal tip, which organizes all of the inner tubing and prevents tangling or overlapping of the DGF tail and locking catheter.

[0034] In another embodiment, the entire guide sheath can be configured with multiple lumens to organize the inner tube. In one exemplary embodiment, the separator can have four lumens: three outer lumens surrounded by a central lumen. The stent holder sheath can pass through the central lumen of the separator, and the locking catheter can pass through each of the three outer lumens.

[0035] In one aspect, the VHPL can include a valve chamber, in which the heart valve leaflet replacement device can be crimped / shrunk to fit within the valve chamber at the distal end of the VHPL system, and then selectively expanded and positioned to an operable size upon removal from the valve chamber of the VHPL system.

[0036] In one aspect, a stent holder can be configured to fit within the lumen of the valve chamber and facilitate release of the prosthetic valve. In this aspect, the stent holder can be configured to attach to the distal tip of a stent holder sheath extending proximally to the VHPL system, and the position of the stent holder within the valve chamber can be controlled by manipulating the stent holder sheath proximally to the VHPL system.

[0037] In one aspect, the valve chamber sheath can be configured to be steerable or non-steerable to fit within the lumen of the stent holder sheath. The valve chamber sheath can optionally be configured as a tube or a solid rod.

[0038] In an exemplary embodiment, a stent can be loaded into the valve chamber by crimping it onto the stent holder sheath proximal to the stent holder. The prosthesis can then be released from the valve chamber by distally advancing the valve chamber sheath while holding the stent holder in place. The stent holder prevents distal movement of the prosthesis, and distal movement of the valve chamber releases the prosthetic valve from the valve chamber, first proximal and then distal.

[0039] In one exemplary embodiment, three DGF head members can be initially implanted into the annulus: one at the medial commissure, one at the lateral commissure, and one at the center of the posterior annulus. The slits on the valve chamber align with the medial edge, lateral edge, and central holes in the atrial flaring portion of the contracted prosthetic valve, respectively, so that the subsequent DGF tails can be easily delivered through the corresponding holes in the atrial flaring and then through the corresponding locking catheter of the valve housing positioning and locking system.

[0040] In one embodiment, the VHPL system can be inserted into a patient and the DGF tail can be tensioned to guide the valve chamber, and thus the prosthetic valve, into the operating position of the previously implanted DGF head member. Once at the mitral annulus, the valve chamber sheath can be advanced to release the prosthetic valve from the atrial flaring portion, and this can continue until the entire ventricular portion of the prosthetic valve is released.

[0041] In one embodiment, one or more sheaths in the MSML delivery system can be configured to be deflectable and / or steerable to better position the heart valve leaflet replacement system. This embodiment further contemplates that the heart valve leaflet replacement system is implanted into the mitral valve annulus via a transfemoral, transseptal procedure. To this end, a docking sheath can be inserted into the femoral vein and advanced to the inferior vena cava, and then its distal tip can be articulated and bent from the inferior vena cava through a transseptal puncture site in the fossa ovalis to gain access to the left atrium. A VHPL system can be inserted through the docking sheath and advanced to the left atrium. The stent holder and valve chamber sheath can be advanced, and the stent holder sheath can be articulated to bend the stent holder sheath tip toward the left ventricle and center the valve chamber at the mitral annulus opening.

[0042] In one aspect, the prosthesis can be secured in place in one or more implanted DGF head members before fully releasing the contracted prosthesis from the valve chamber by tensioning each DGF tail and engaging a corresponding DGF locking device with the prosthesis.

[0043] In one aspect, the VHPL system can be configured with a suture tensioning mechanism that can be operated to apply tension to the DGF tails individually, or optionally to multiple DGF tails simultaneously, to guide the positioning and fixation of the heart valve replacement system.

[0044] In one embodiment, after deployment of the valve, the DGF locking mechanism can be engaged with the prosthesis by advancing multiple locking catheters distally against the atrial flaring portion of the stent while tensioning the DGF tails.

[0045] In one embodiment, the locking catheter is configured to be flexible and can bend along with the other steerable sheaths during fixation of the prosthesis. In another embodiment, the distal tip of the locking catheter has a larger inner diameter than the DGF locking member so that it can pass over the DGF locking member. In this embodiment, the locking catheter is pressed against the atrial flared portion of the prosthesis until the DGF locking member is pulled through the atrial flared hole.

[0046] In one aspect, the lower ventricular portion of the stent is configured with a mechanism for selectively engaging the VHPL system so that the prosthesis can be guided, positioned, and secured in place in a highly controlled manner. In one exemplary aspect, the stent holder is configured with recesses having a shape complementary to the tabs of the lower ventricular portion of the stent frame, whereby the tabs fit within the recesses of the stent holder and serve to hold the tabs of the stent frame against the inner valve chamber wall until the valve chamber is advanced distally enough to expose the recesses of the tabs.

[0047] In one aspect, the lower ventricular portion of the stent frame can be configured with tabs at the tips of extension members that are longer than the remainder of the stent, such that the tabs are the lowest point of the stent during operation. In one exemplary aspect, the stent frame can be configured to resemble a stingray in shape, with the extension members resembling a stingray's tail and extending longer than the main body of the stent frame, and the tips of the extension members can be configured to engage with the stent holder. In another aspect, the lower ventricular portion of the stent frame can be configured with multiple tabs, holes, or other engagement members at the tips of multiple extension members that are longer than the remainder of the stent. The engagement members can be operably engaged with complementary engagement members, such as recesses or protrusions, on the stent holder or stent holder sheath.

[0048] In an optional embodiment, the prosthesis can be released from the valve chamber, leaving only the tabs of the extension member engaged with the stent holder, allowing it to fully expand within the mitral valve annulus. With the stent tabs still engaged with the stent holder, the locking catheter can be advanced, applying tension to the DGF tail to secure the prosthesis at the location of the implanted DGF member. Those skilled in the art will appreciate that once the prosthesis is released, blood pressure within the left ventricle can cause undesired migration of the prosthesis without a mechanism to hold it in place. Including a mechanism to restrain the prosthesis within the valve chamber until it is secured by the DGF locking member significantly improves the safety of the delivery and implantation process. This mechanism can be achieved by a variety of different engagement members that allow the prosthetic valve device to engage and disengage with portions of the VHPL system during the prosthetic valve deployment process.

[0049] In one embodiment, if paravalvular leak or valve instability exists in the actuation position following deployment of the prosthetic valve and DGF locking member, multiple additional DGF members can be deployed by the DGF delivery system onto the top of the prosthetic valve leaflets, whereby each DGF head member of the additional DGF members is driven through the skirt material of the atrial flaring portion of the prosthesis and embedded into the muscular annulus tissue until the body portion of the DGF body member is flush with the atrial flaring portion of the prosthesis. In this embodiment, no additional fixation mechanism, i.e., locking member, is required for the DGF body member.

[0050] Following implantation of the heart valve replacement system, all components of the MSML delivery system can be removed and a septal closure device can be inserted through the docking sheath to close the hole in the atrial septum. The entire MSML delivery system can then be removed from the body.

[0051] The various embodiments described herein may include additional systems, methods, features, and advantages that are not necessarily expressly disclosed herein, but will become apparent to one of ordinary skill in the art upon review of the following detailed description and the accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within this disclosure and protected by the accompanying claims. [Brief explanation of the drawings]

[0052] A better understanding of the features and advantages of the present subject matter will be obtained by reference to the following detailed description setting forth illustrative embodiments and the accompanying drawings, in which features and components are shown to emphasize the general principles of the present disclosure. Corresponding features and components throughout the drawings may be designated by corresponding reference numerals for consistency and clarity.

[0053] [Figure 1]1A-1D show various schematic views of a prosthetic valve. FIG. 1A shows a front view of the stent frame of the prosthetic valve, illustrating the atrial flaring portion, which features multiple through-holes, and the lower ventricular portion, which features an elongated member with tabs. FIG. 1B shows a side view of the stent frame of the prosthetic valve. FIG. 1C shows a front view of the prosthetic valve, illustrating three leaflets. FIG. 1D shows a side view of the leaflet attachment to the prosthetic valve stent, illustrating the prong structure of the middle leaflet attachment to the inner surface of the stent. [Figure 2] Figures 2A-2C show an exemplary embodiment of a DGF member. Figure 2A shows the components of the DGF member. Figure 2B shows a top view of the DGF head member. Figure 2C shows the DGF locking member and its components. [Figure 3] 3A and 3B are schematic diagrams of a stent secured in place by multiple DGF elements. Fig. 3A is a side view showing the flaring atrial portion of the stent sandwiched between the DGF head and the DGF locking element. Fig. 3B shows the position of three DGF elements along the flaring portion of the prosthetic valve stent. [Figure 4] FIG. 4 is a schematic diagram illustrating one embodiment in which an additional DGF member without a DGF locking member is implanted in the atrial flaring portion of the stent. [Figure 5] Figure 5 is a schematic diagram of the docking system and valve housing positioning and locking system mounted on the angled base. [Figure 6] Figure 6 shows a schematic diagram of the valve housing positioning and locking system catheter, with the valve chamber attached to the distal section, followed by the stent holder mounted on the steerable stent holder sheath, and multiple locking catheters, all within the guide sheath and separated by separators. [Figure 7] FIG. 7 is a perspective view of a valve chamber attached to the distal end of a valve chamber sheath. [Figure 8]Figures 8A-8D illustrate the heart valve leaflet replacement system and the steps for loading, releasing, and securing the prosthetic valve. Figure 8A shows the prosthetic valve (stent only, for clarity) being loaded into the valve chamber. Figure 8B shows the prosthetic valve being released by advancing the valve chamber distally. Figure 8C shows the prosthetic valve being stabilized during fixation by a mechanism within the valve chamber, and the locking catheter being guided by the DGF member tail (not shown) to the DGF member (not shown) in the flared section of the prosthetic valve, securing the prosthetic valve in place. Figure 8D shows the prosthetic valve is secured with the first three DGF members, and the entire valve housing, positioning, and locking system can be removed. DETAILED DESCRIPTION OF THE INVENTION

[0054] The present invention may be more readily understood by reference to the following detailed description, examples, figures, and claims, as well as the accompanying text. However, before the present devices, systems, and / or methods are disclosed and described, it is to be understood that the present invention is not limited to the particular devices, systems, and / or methods disclosed, unless otherwise specified, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0055] The following description is provided as a useful teaching of exemplary devices, systems, and methods. To this end, those skilled in the art will recognize and appreciate that many variations can be made to the various aspects described herein while still obtaining the beneficial results of the present invention. It will also be apparent that some of the desired advantages of embodiments of the present invention can be obtained by selecting some of the features without utilizing other features.

[0056] Accordingly, those skilled in the art will recognize that many modifications and adaptations are possible and can even be desirable in particular circumstances and are a part of the present invention. Accordingly, the following description is provided as an illustration of the principles of the invention, not in limitation.

[0057] For clarity, it should be understood that the present disclosure focuses on the treatment of functional mitral regurgitation, however, it is contemplated that the heart valve leaflet replacement systems and related methods may be used or otherwise configured to be used to treat other types of mitral regurgitation or to replace other diseased valves in the human heart, such as the tricuspid valve, or in other mammals similarly afflicted with valve defects.

[0058] As used throughout, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to a "valve leaflet" can include two or more such leaflets unless the context dictates otherwise.

[0059] Ranges can be expressed herein as from "approximately" one particular value and / or to "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. Further, it will be understood that the endpoints of each range are significant both in relation to the other endpoint and independently of the other endpoint.

[0060] As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes cases where the event or circumstance occurs and cases where it does not occur.

[0061] As used herein, the word "or" means any one element of a particular list and also includes any combination of elements of that list. Furthermore, it should be noted that conditional language, particularly "can," "could," "might," or "may," unless otherwise specified or understood within the context in which it is used, is generally intended to convey that certain aspects include certain features, elements, and / or steps, while other aspects do not. Thus, such conditional language is generally not intended to imply that features, elements, and / or steps are somehow required for one or more particular aspects, or that one or more particular aspects necessarily include logic for determining whether or not those features, elements, and / or steps are included or performed in any particular embodiment, with or without user input or prompting.

[0062] Components are disclosed that can be used to implement the disclosed methods and systems. These and other components are disclosed herein, and when combinations, subsets, interactions, groups, etc. of these components are disclosed, it is to be understood that, although specific reference to each of their various individual and collective combinations and permutations is not expressly disclosed, each is specifically contemplated and described herein for all methods and systems. This applies to all aspects of this application, including, but not limited to, steps in the disclosed methods. Thus, where there are various additional steps that can be performed, it is to be understood that each of those additional steps can be performed in any specific embodiment or combination of embodiments of the disclosed methods.

[0063] The present method and system may be more readily understood by reference to the following detailed description of the preferred embodiments.

[0064] Throughout this specification, the terms "artificial valve," "prosthesis," "valve stent," "heart valve leaflet replacement device," and "valve device" are used interchangeably and are intended to refer to the heart valve replacement devices described herein.

[0065] Throughout this specification, the terms "distal" and "proximal" are used relative to an operator during use of the delivery system, with "distal" referring to the portion of the device further from the operator or in the direction away from the operator, and "proximal" referring to the portion of the device closer to the operator or in the direction toward the operator.

[0066] Those skilled in the art will appreciate the complexity of the transcatheter techniques and systems used to successfully place a prosthetic valve within the heart. Such methods involve numerous components and steps. It will be understood that even though the components and steps are described in different parts of this specification, they do not necessarily have to be used or performed in the order described herein.

[0067] The heart valve replacement systems described herein can be utilized with any heart valve replacement device or prosthesis. It is contemplated that the heart valve replacement systems described herein include a series of systems that can be used simultaneously to deliver a prosthetic valve 2 into a subject's heart.

[0068] In one aspect, a heart valve replacement system includes a multi-stage, multi-lumen (MSML) delivery system that can be configured to deliver a heart valve replacement device or prosthesis 2 to an implantation site or to a native mitral valve annulus. Such systems can include a dual guide and fixation (DGF) delivery system and a valve housing positioning and locking (VHPL) system. In one aspect, the DGF delivery system described herein is configured to implant multiple DGF members into the native valve annulus to assist in guiding and securing the prosthetic valve to a target implantation location. In one aspect, a novel VHPL system can be configured to accommodate and organize multiple DGF member tails, a crimped prosthetic valve, and designed to incrementally release the crimped prosthetic valve and secure the prosthetic valve with the implanted DGF members via a DGF body fixation mechanism.

[0069] In one embodiment, the MSML delivery system can access the mitral valve via the inferior vena cava, enter the right atrium, cross the interatrial septum into the left atrium, and then articulate downward toward the native mitral valve annulus. It is contemplated that the MSML delivery system will be navigated to the implantation site via the superior vena cava, following the same path as described above toward the native mitral valve annulus.

[0070] 1A-1D , in one embodiment, the crescent-shaped stent 3 of the MSML delivery system can include an atrial flaring portion 4, a ventricular portion 5, and a neck portion 6. In one embodiment, the atrial flaring portion 4, the ventricular portion 5, and the neck portion 6 are continuously connected to form a single body. At least a portion of the atrial flaring portion 4 and / or a portion of the ventricular portion 5 can be formed to be self-expandable or balloon-expandable to a desired operating position. In this embodiment, it is contemplated that the stent 3 is conventionally laser cut or braided into a desired radially collapsible and expandable shape. Thus, it is further contemplated that the stent 3 can include multiple operatively linked components to form an expandable mesh or non-mesh body that can be made of metal, polymeric material, or biologically derived material, including, but not limited to, metals with inherent shape memory properties, including cobalt chromium, stainless steel, or nitinol. It is contemplated that stent 3 may optionally include multiple vertical rigid structures connected by flexible materials such as biological tissue, synthetic materials such as polymers, etc. Stent 3 may be configured to allow natural dynamic movement of the remaining native valve leaflet(s) to coapt with one or more prosthetic valve leaflets 10.

[0071] In one embodiment, it is contemplated that the atrial flaring portion 4 of the stent 3 can be configured to be positioned at and / or above the native annulus upon implantation. In this embodiment, the atrial flaring portion 4 of the stent 3 can be configured to easily secure and seal the prosthesis 2, thereby helping to prevent paravalvular leakage and prolapse after implantation. The mitral valve annulus is asymmetric. The atrial flaring portion 4 of the prosthesis 2 can be configured to cover or drape over the posterior portion of the mitral valve annulus, which is divided into three scallops: P1, P2, and P3. In one embodiment, the atrial flaring portion 41 can span two commissures: the AC-anterior commissure and the PC-posterior commissure. In another embodiment, the atrial flaring portion 4 can include both an anterior and a posterior atrial flaring portion to cover the entire circumference of the mitral valve when operatively deployed.

[0072] 1A and 1B, at least a portion of the atrial flaring portion 4 has a bend 14. In this embodiment, the bend is an upward curl away from the heart chamber wall, preventing excessive expansion of the heart chamber, which may result in deep penetration of the heart tissue. In a further embodiment, the upward curl is oriented in a direction approximately ninety to one hundred twenty degrees (90-120°) from the atrial flaring portion 4. In a further embodiment, the bend 14 is only in the cell struts of the atrial flaring portion 4, and therefore does not interfere with or distort the circular shape of the through-hole 9 in the atrial flaring portion 4.

[0073] In another embodiment, at least a portion of the atrial flaring portion 4 is configured with a plurality of through-holes 9 that selectively engage with the DGF member 101. In one embodiment, the through-holes 9 are designed to have a circular shape and can connect cell struts and form bridge connections with adjacent cells. A through-hole 9 can be designed for each bridge connection of the atrial flaring portion 4. In another embodiment, the through-holes 9 can be designed in locations that are fewer than the total number of bridge connections of the atrial flaring portion 4.

[0074] In one embodiment, the entire circumference of the ventricular portion 5 of the stent can be bent toward the left ventricular wall. Referring to FIG. 1B, the bend angle 15 can be between sixty and one hundred twenty degrees (60-120°) relative to the atrial flaring portion 4 of the stent 3.

[0075] 1A and 1B, in one embodiment, stent 3 is configured with extension members 7. In one embodiment, extension members 7 can be configured as straight segments. In another embodiment, extension members 7 can be configured with a short length and a tab 8 at a distal end that is continuously connected to the straight segments.

[0076] In one embodiment, the tab 8 can be configured to have a greater width than the remainder of the extension member 7 .

[0077] In an exemplary embodiment, at least one extension member 7 can be designed into the center of the distal portion of the ventricular portion 5 of the stent. In this embodiment, in the activated position, extension member 7 is the longest section of the stent 3 that extends the furthest into the left ventricle. In this embodiment, extension member 7 is approximately two to seven millimeters (2-7 mm) longer than the rest of the stent 3.

[0078] In an exemplary embodiment, as shown in FIG. 1B, extension member 7 can be configured to curve radially inward to avoid interference with the posterior wall of the ventricle during operation.

[0079] In optional embodiments, extension members 7 can be positioned at other sections along the circumference of the stent's ventricular portion 5. In an exemplary embodiment, extension members 7 can extend from one or more lower cells of the ventricular portion 5 of the stent 3, as shown in FIG. 1A.

[0080] 1A , in one embodiment, tab 8 of extension member 7 is configured to retain the prosthesis during release from the VHPL system to prevent it from inadvertently moving before the DGF fixation mechanism is engaged. In this embodiment, (VHPL) system 1 is selectively designed to connect to tab 8 of extension member 7 until the prosthesis is secured in the target implantation location. Once the prosthesis 2 is fully secured in the implantation location, tab 8 can be selectively released from (VHPL) system 1 to allow the prosthesis 2 to be disengaged from (VHPL) system 1.

[0081] In one embodiment, the tab 8 is configured to have a dome-shaped, circular, square, rectangular, triangular, or irregular shape. In another embodiment, the tab 8 is configured to have at least one through hole.

[0082] In one embodiment, at least one prosthetic leaflet 10 is attached to the interior surface of the ventricular portion 5 of the stent 3, as shown in Figures 1C and 1D. In a further embodiment, at least one prosthetic leaflet 10 of the plurality of prosthetic leaflets has a different shape. In another embodiment, at least one prong structure 11 of at least one prosthetic leaflet 10 includes multiple prong structures 11. It is contemplated that at least one prong structure 11 is coupled to a free end of the leaflet.

[0083] In one embodiment of the MSML delivery system, the prosthetic leaflet 10 can be configured to be similar in shape to the native posterior mitral valve leaflet.

[0084] It is contemplated that the at least one prosthetic leaflet 10 and the at least one prong structure 11 may be comprised of a single flat piece of flexible material, such as biological tissue, a polymeric material, or fabric, and may be attached to the stent 3 to form a 3D dome-like structure that bulges radially inward from the stent attachment point. The prosthetic leaflet 10 may be configured to be movable during the cardiac cycle, moving closer to the inner surface of the stent during diastole and farther away from the inner surface of the stent during systole.

[0085] 1C, in one embodiment, at least one prosthetic valve leaflet 10 can include three leaflets: two small lateral leaflets and one large central leaflet, which form three distinct dome-like structures extending radially from the inner surface of the ventricular portion 5 of the stent 3. In this embodiment, the three leaflets can be configured to span the circumference of the lower ventricular portion of the stent. The prosthetic valve leaflets 10 can be closely attached to the inner surface of the stent 3 to prevent transvalvular leakage during operation. Furthermore, in this embodiment, the leaflets can be configured to bulge radially inward from the stent 3 so that they are positioned in the blood flow path during operation and can close the mitral orifice under systolic blood pressure.

[0086] 1C and 1D , the smaller lateral leaflets are asymmetrical, with shorter lateral edge lengths corresponding to the shape of the lower ventricular portion 5 of the stent 3. In one embodiment, the larger central leaflet has a symmetrical shape, with two prong structures 11 extending from its free end. Furthermore, in this embodiment, the free ends of the prongs 11 can be attached to a portion of the stent 3, for example, by suturing the ends of the prongs 11 to the stent through through-holes 12 in the lower ventricular portion 5 of the stent 3. In this embodiment, the prong structures 11 prevent excessive bulging and prolapse of the large central leaflet and also help evenly distribute stress in the prosthetic leaflets 10, which is important for durability. Optionally, one or more prong structures 11 can be added to the lateral leaflets.

[0087] 5, the MSML delivery implantation system can include a docking system 326, a DGF member delivery system, and a VHPL system 1, which can be attached to a handle platform 301 to facilitate the delivery process. The handle platform 301 is attached to a base 324.

[0088] In one embodiment, the base 324 features a mechanism that allows the angle of the MSML system to be adjusted for optimal entry into the body access site. The base 324 can be made of a rigid material such as, but not limited to, metal, plastic, etc.

[0089] In one embodiment, the docking system 326 includes a docking sheath 327 and a docking handle. The docking sheath 327 can initially enter the body through an introducer sheath. In one exemplary embodiment, the docking sheath 327 can be configured to be deflectable to access the implantation site. In this embodiment, the distal end of the docking sheath 327 can be configured to bend up to one hundred eighty degrees (180°) relative to the proximal end of the sheath.

[0090] Once the docking system 326 is in place, the DGF system can be introduced. In this embodiment, multiple DGF elements 101, such as those shown in Figure 2, can be delivered sequentially or simultaneously and implanted in the desired locations in the valve annulus.

[0091] In a further embodiment, it is contemplated that the method of implanting the DGF member 101 is performed prior to delivery of the prosthesis 2.

[0092] Referring to FIG. 2A, in one embodiment, the DGF member 101 can comprise a DGF head member 102, a DGF body member 103, a DGF locking member 105 and a tether 114, which are intended to be permanently implanted within the mitral valve annulus.

[0093] In another embodiment, implantation of an additional DGF member 101A can be performed after delivery and fixation of the prosthesis 2. In this embodiment, the DGF member 101A can be configured to have a DGF head member 102, a DGF body member 103, and a DGF tether 114 that forms a loop.

[0094] In one embodiment, as shown in FIG. 2B, the DGF member 101 is configured to include a head portion 102 that engages with the valve annulus or surrounding tissue, and a body portion 103 having an engagement element 109 that engages with the DGF delivery catheter.

[0095] It is further contemplated that the DGF head member 102 is configured to be embedded in the native annular tissue and resist separation after implantation. In exemplary embodiments, the DGF head member 102 can have, but is not limited to, a helical, coil, prong, screw, or barbed hook shape that engages the annular tissue. The DGF head member 102 can be formed from, but is not limited to, nitinol, stainless steel, cobalt chrome, polymer, or the like.

[0096] In one exemplary embodiment, the DGF head member 102 is configured with a coil 108 having a length of approximately four to ten millimeters (4-10 mm), a diameter of approximately two to five millimeters (2-5 mm), and is formed from wire having a diameter of 0.25 to 1 millimeter (0.25-1.0 mm).

[0097] In one embodiment, the DGF head member 102 can be configured with a stabilizing member 111 to facilitate controlled implantation of the DGF head member 102 into the annular tissue via an active DGF delivery system. In one exemplary embodiment, the stabilizing member 111 is configured as a straight wire having a diameter of approximately 0.25 to 1 millimeter (0.25 to 1.0 mm) extending axially through the center of the helix and having a sharpened tip extending approximately 1 to 3 millimeters (1 to 3 mm) beyond the end of the helix. In a further embodiment, the stabilizing member 111 can be configured as a needle having a sharpened distal tip 112 extending axially approximately 1 to 5 millimeters (1 to 5 mm) beyond the DGF head member coil 108. During operation, the stabilizing member 111 can be used to engage the annular tissue before threading the DGF head member 102 into the tissue, which helps prevent undesired movement of the DGF delivery system and thereby facilitates implantation of the DGF head member 102 at a desired location along the annulus. It will be appreciated that such stabilizing members 111 can be used to engage the DGF member with tissue at the preferred implantation site and prevent the DGF member from migrating from the target location during implantation.

[0098] In further embodiments, the tip 119 of the coil 108 of the DGF head member 102, as shown in FIG. 2A, can be shaped and configured to facilitate penetration into annular tissue. In one exemplary embodiment, the tip 119 of the coil 108 is sharp and curved at the same pitch as the remainder of the coil 108. In another exemplary embodiment, the tip 119 can be straight. In any other embodiment, the tip 119 can have an arc length of approximately one to three millimeters (1-3 mm).

[0099] In another embodiment, as shown in FIG. 2B, the DGF body member 103 comprises a base and an extruded section 109 configured to engage a DGF delivery catheter. In this embodiment, the base and extruded section can be integral. In a further embodiment, the extruded section 109 has a dimension smaller than the outer diameter of the base so that the DGF delivery catheter can engage it.

[0100] In one embodiment, extrusion section 109 has three through holes, two of which are configured to attach DGF locking member 105 via tether 114. In this embodiment, a distal section of tether 114 is secured to the DGF body via two attachment holes 110, an intermediate portion of tether 114 is configured to form a loop through DGF locking member 105 to restrain DGF locking member 105 from moving along tether 114, and a proximal section of tether 114 proximal to DGF locking member 105 is configured to have a loop.

[0101] In one embodiment, a DGF body member 103 having a DGF locking member is configured to attach a DGF tail member 104 via a proximal loop of a tether 114 .

[0102] In one embodiment, the tether 114 can be straight, curved, single, or double or multiple strands.

[0103] In one embodiment, the distance between the DGF body member 103 and the DGF locking member 105 can be approximately 0.4 to 1 millimeter (0.4 to 1.0 mm) so that the atrial flaring portion 4 of the stent 3 can fit snugly between the DGF body member 103 and the DGF locking member 105 in the activated position. Optionally, each DGF body member 103 can include multiple DGF locking members 105, and the spacing between adjacent DGF locking members 105 can be approximately 0.4 to 2 millimeters (0.4 to 2.0 mm). The DGF body member 103 and the DGF locking member 105 can be separated on the tether 114, for example, by tying multiple knots on the tether 114. In a further embodiment, if the tether 114 is made of metal, plastic, or the like, small protrusions can be welded, molded, or attached to the flexible component to maintain the spacing.

[0104] In one embodiment, it is contemplated that the tether 114 including the DGF locking member 105 is formed from a suture, string, wire, or a tether made from a polymeric material.

[0105] 2A, it is contemplated that the DGF head member 103 and the DGF body member 103 may be formed as a single component or, optionally, by joining different parts by one or more of welding, bonding, adhesives, etc. that can resist separation during in vivo loading. Additionally, in this embodiment, the DGF head member 103 and the DGF body member 103 may be formed from a durable, biocompatible material that can be permanently implanted in the human body and resist damage, for example, but not limited to, stainless steel, cobalt chromium, nitinol, non-absorbable polymers, bio-derived materials, etc.

[0106] In one exemplary embodiment, it is contemplated that the DGF locking member 105 is configured to only allow passage of a portion of the atrial flaring portion 4 of the stent 3 guided by the DGF tail member 104 in one direction, and to resist subsequent movement of the atrial flaring portion 4 of the stent 3 in the opposite direction.

[0107] In one aspect, the DGF locking member 105 can be configured to be selectively compressed to a diameter smaller than the diameter of the through-hole 9 in the atrial flaring portion 4 of the stent 3 to allow it to pass through the hole, and then selectively re-expanded to its original size larger than the diameter of the through-hole 9 to prevent backward movement of the DGF locking member 105 through the hole.

[0108] In one exemplary embodiment, as shown in FIG. 2C, the DGF locking member 105 is configured to have a proximal portion 107 and a distal portion 106. In one embodiment, the locking member 105 can have an overall length of approximately 1.5 to 3.5 millimeters. The length of the proximal portion 107 can be approximately 0.5 to 1.5 millimeters. The length of the distal portion 106 can be approximately 1 to 2 millimeters (1.0 to 2.0 mm).

[0109] In one embodiment, the proximal portion 106 includes a tubular shape having an outer diameter in the range of approximately 0.5 to 1.5 millimeters and an inner diameter in the range of approximately 0.4 to 1.2 millimeters. In one embodiment, the distal portion 106 of the DGF member 101 includes a plurality of radially compressible legs that form a conical shape in its original state. In one embodiment, the outer diameter of the proximal portion of the locking member is smaller than the inner diameter of the through-hole 9 of the atrial flare 4 of the stent 3. Furthermore, in this embodiment, the distal tip 107 of the DGF locking member 105 can be configured to have a maximum fully expanded outer diameter that is larger than the inner diameter of the through-hole 9 of the atrial flare 4 of the stent 3 so that it cannot pass through the through-hole 9. The proximal portion 107 and distal portion 106 of the DGF locking member 105 can be connected to each other and be continuous.

[0110] In operation, tension can be applied to DGF member tail 104 to retract proximal portion 107 of DGF locking member 105 into through-hole 9, and when distal portion 106 of DGF locking member contacts the edge of through-hole 9, it radially collapses so that its outer diameter is smaller than the inner diameter of through-hole 9, thereby allowing DGF locking member 105 to pass through through-hole 9. Once DGF locking member 105 has completely passed through through-hole 9, DGF distal portion 106 can re-expand to its original size to prevent rearward movement of DGF locking member 105 through through-hole 9.

[0111] It is contemplated that the DGF locking member 105 may be manufactured, for example, by laser cutting a tube to form multiple slits and bending the legs radially outward to deform the legs. In an exemplary embodiment, the slits may have a width of approximately 0.3-0.6 millimeters and a length of approximately 0.6-1.5 millimeters. A heat treatment process may be performed to form the final flare cone geometry. The legs are designed to be selectively compressed to pass through the through-hole 9 and then re-expand to return to their original shape once they have completely passed through the through-hole 9.

[0112] In one embodiment, it is contemplated that one or more DGF locking members 105 may be formed from, but are not limited to, polymers, polytetrafluoroethylene (PTFE), stainless steel, nitinol, and metal-like materials, or combinations of these materials.

[0113] In one embodiment, the extruded section 109 of the DGF body member 103 can be configured as a protrusion shaped to fit snugly into a complementary recess in the distal tip of the DGF delivery catheter, such that when the protrusion engages with the distal DGF delivery catheter, rotating the DGF delivery catheter in one direction engages the DGF head member 102 with the tissue, and rotating it in the other direction disengages the DGF head member 102 from the tissue.

[0114] In an exemplary embodiment, as shown in FIG. 2B, the extruded section 109 of the DGF body member 103 can have a rounded rectangular shape that protrudes approximately one-half to two millimeters (0.5-2 mm) from the base of the DGF body member 103.

[0115] 2A, a loop of the tether 114 can be configured to engage with the DGF tail member 104. In one exemplary embodiment, one end of the DGF member tail 104 can be inserted through the loop of the tether 114, and both free ends of the DGF member tail 104 can extend through and from the proximal side of the MSML delivery system.

[0116] In one embodiment, the DGF member tail 104 links the DGF delivery system and the VHPL system 1. In this embodiment, the DGF member tail 104 functions as a bridge element that guides the VHPL system 1 from the access site to the implantation site.

[0117] In one embodiment, after deployment of the DGF member 101, it is contemplated that the two free ends of the DGF member tail 104 are inserted through the atrial flare through-holes 9 of the prosthesis 2. Thus, both free ends of the DGF member tail 104 are also inserted into the VHPL system 1, such that when an operator pulls the protruding free end of the DGF member tail 104 away from the body, the DGF member tail 104 becomes taut and guides the components of the VHPL system toward the DGF member 101 implanted in the valve annulus. Further tension on the DGF tail member 104 helps secure the prosthesis to the valve annulus via the DGF locking member 105 of the DGF member 101. Following implantation of the device, the DGF member tail 104 can be removed from the VHPL system and from the body by pulling one free end of the DGF member tail 104.

[0118] In another embodiment, one end of the DGF tail member 104 can be tied into a loop and the other end can extend from the body proximally to the MSML delivery system. In this embodiment, once the heart valve leaflet replacement device is implanted and secured in place, the trailing DGF tail can be cut by conventional cutting methods or a transcatheter suture cutting device.

[0119] It is contemplated that the DGF tail member 104 is configured to fit within the inner catheter of the MSML delivery system and is long enough to extend from and exit the MSML delivery system from the DGF body member 103. In this embodiment, the DGF tail member 104 can have a diameter of about 0.1 to 0.5 millimeters and a length of at least about 2.5 meters.

[0120] 3A, in one embodiment, after implantation of the prosthesis 2, the atrial flaring portion 4 of the prosthesis 2 is sandwiched between the DGF locking member 105 and the DGF body member 103. It should be appreciated that the spacing between the DGF locking member 105 and the DGF body member 103 is optimized to limit movement of the prosthesis 2 after implantation.

[0121] As shown in FIG. 3B, in one embodiment, at least three DGF members 101 are implanted, two DGF members 101 on the sides of the stent 3 and one in the center of the atrial flaring portion 4.

[0122] In one embodiment of a method using the MSML delivery system, at least three DGF members 101 are implanted in the valve annulus prior to implanting the prosthesis 2 via the VHPL system 1. Once the prosthesis 2 is implanted, at least one additional DGF member 101A (a DGF member without a DGF locking member 105) is implanted above the atrial flaring portion 4 of the prosthesis 2. The DGF member 101A can penetrate the skirt material of the prosthesis and be anchored within the tissue. In another embodiment, the DGF member 101A can be configured to penetrate the through-holes 9 in the atrial flaring portion 4. Referring to FIG. 4 , as shown, three DGF members 101 are implanted at the sides (P1 and P3) of the atrial flaring portion 4, and one DGF member 101 is implanted in the center (P2) of the atrial flaring portion 4. Additional DGF members 101A can be implanted between the DGF members 101 at P1 and P2 and between the P2 and P3 positions. As will be understood by those skilled in the art, implanting the additional DGF member 101A can eliminate paravalvular leakage between the prosthesis 2 and the valve annulus and prevent dislodgement of the prosthesis 2, thereby enabling normal coaptation between the artificial valve leaflets and the native valve leaflets.

[0123] For clarity, the following description outlines one exemplary VHPL System 1 design for successfully delivering and securing a prosthesis. The shape and design of the outer compartment, and the structure and assembly of the VHPL System 1 controls can be varied as long as they perform the same general functions, i.e., translating or restricting movement of a sheath, tensioning a wire or tether, etc. Therefore, the examples provided here are for better explanation and clarity and are not intended to be limited to the specific design of any component.

[0124] As shown in FIG. 6, in one embodiment, the VHPL system 1 can include an outer sheath 306 that houses multiple catheters and tubes that function to deliver the prosthesis.

[0125] In one embodiment, the outer sheath 306 can be a guide sheath. In this embodiment, the guide sheath 306 can house a stent holder sheath 206 that is attached to a valve chamber 201 that houses a prosthetic valve in a collapsed stage. In this embodiment, the stent holder sheath 206 can be deflected to guide and position the valve chamber 201 from the access site into the left ventricle. In this embodiment, the valve chamber 201 is connected to a valve chamber sheath 203 that can slide along the inner lumen of the stent holder sheath 206. In this embodiment, the sliding of the valve chamber sheath 203 is the mechanism that releases the prosthetic valve.

[0126] In one embodiment, the outer sheath 306 can accommodate multiple locking catheters 317. In this embodiment, the locking catheters 317 and stent holder sheaths 206 can be organized in the multi-lumen guide sheath 306, all of which can be inserted into the body via the larger diameter docking sheath 327. During operation, the prosthetic valve 2 is guided to the previously implanted multiple DGF members 101 by tracking over the DGF tail 104, which passes through the atrial flared hole 9 of the shortened prosthetic valve 2 and through the corresponding locking catheter 317 and is loaded into the proximal end of the VHPL system 1.

[0127] In this embodiment, the valve chamber sheath 203, stent holder sheath 206, locking catheter 317, and guide sheath 306 are configured to move independently of the docking sheath 327 to achieve proper positioning. Additionally, the valve chamber sheath 203 and stent holder sheath 206 are configured to move together, independent of the locking catheter 317 and guide sheath 306. To deploy the valve 2, the valve chamber sheath 203 can be advanced relative to the stent holder sheath 206. To secure the prosthesis 2 in place, each locking catheter 317 must be advanced individually while tensioning the DGF member tail 104 individually. Once the prosthesis 2 is fully released and secured in place, all sheaths can be withdrawn together from the patient's body.

[0128] Those skilled in the art will appreciate the need for a precise and stable valve release mechanism. Therefore, the VHPL system can be mounted on a handle platform 301, for example, as shown in FIG. 5 . In the illustrated example, the handle platform 301 is positioned proximal to a docking system 326 on a base 324. The outermost guide sheath 306 and associated inner sheath on the handle platform 301 are inserted into a docking sheath 327. The handle platform 301 is configured to allow the guide sheath 306, stent holder sheath 206, and valve chamber sheath 203 to simultaneously slide a specific distance along the base 324. In a further embodiment, the handle platform 301 is designed to prevent rotation of the guide sheath 306 throughout the valve delivery process. The handle platform 301 can be made of any durable, rigid material, such as metal or plastic.

[0129] In one embodiment, the guide sheath 306 is comprised of a distal portion and a proximal portion.

[0130] In one embodiment, the distal portion of the guide sheath 306 can be made of a flexible material composition that conforms to the sharp curves of the deployment path in the native heart chambers (one of which includes the inferior vena cava to the septum), and the proximal portion of the guide sheath 306 can be made of a stiffer material composition than the distal portion to prevent buckling during the delivery process.

[0131] In one embodiment, the distal end of guide sheath 306 can be configured with separator 307. In this embodiment, separator 307 of guide sheath 306 acts as an organizer that separates the inner sheath within guide sheath 306 to avoid entanglement throughout the prosthetic valve delivery process.

[0132] In one embodiment, the separator 307 of the guide sheath 306 is a separate component secured to the distal portion of the guide sheath 306. In one embodiment, the separator 307 may be a cylindrical component having multiple lumens. In one embodiment, the separator 307 has multiple lumens, for example, four lumens, and may include one central lumen and three outer lumens surrounding the central lumen. In this embodiment, there is a central lumen that houses the deflectable stent holder sheath 206 and three peripheral lumens that house the locking catheter 317. As can be seen, the separator 307 organizes the inner sheath within the guide sheath 306 to avoid entanglement throughout the delivery process of the prosthetic valve 2.

[0133] In another optional embodiment, the guide sheath 306 can be configured as a multi-lumen tube along its entire length without additional separators 307. In this embodiment, the multi-lumen guide sheath can have four lumens, one central and three peripheral, all separated by walls.

[0134] In one embodiment, the stent holder sheath 206 is flexible and translatable along the handle platform. In this embodiment, the stent holder sheath 206 can be attached to a handle system 309, 301, which allows an operator to deflect a distal portion of the stent holder sheath 206. In a further embodiment, the stent holder sheath 206 can be attached to a slidable handle system.

[0135] 6, in one embodiment, the deflectable stent holder sheath 206 can be positioned within the central lumen of the guide sheath separator 307. In one embodiment, the deflectable stent holder sheath 206 can be configured as a composite sheath that includes sections of varying stiffness and flexibility, among other notable properties such as pushability and kink resistance, that allow the stent holder sheath 206 to deflect from 0° to 180° while maintaining its integrity and ability to deflect the sheath contained within.

[0136] In one embodiment, the deflectable stent holder sheath 206 can include three sections: a distal section, a mid-section, and a proximal section. In this embodiment, the distal section is a rigid, straight section in which the prosthetic valve 2 is retracted. The mid-section of the deflectable stent holder sheath 206 is a flexible, coiled section that has the inherent ability to bend through a small radius without kinking or damaging the underlying sheath. The proximal portion of the deflectable stent holder sheath 206 is a long, rigid section that provides stability and rigidity across the VHPL 1. At least one pull wire is embedded within the wall of the deflectable stent holder sheath 206. The deflection of the flexible mid-section can be controlled by selectively tensioning the at least one pull wire.

[0137] In this embodiment, the stent holder 207 serves as a safety feature within the delivery system to maintain control and repositionability of the prosthetic valve before it is fully deployed and secured to the native mitral valve. The tabs 8 of the extension members 7 of the stent 3 are released from the stent holder 207 when the valve chamber 201 translates distally past the stent holder 207, thereby completely releasing the prosthetic valve from the valve chamber 201.

[0138] In one embodiment, the distal section of the VHPL system 1 can include a valve chamber 201 for accommodating the prosthetic valve 2 within the VHPL system 1. In this embodiment, the prosthetic valve 2 can be retracted to fit within the valve chamber 201 at the distal end of the VHPL 1, and then selectively expanded and positioned to a working size upon release from the valve chamber 201.

[0139] 7, the valve chamber 201 can include a cylindrical or conical shape, closed at its distal end, with an inner diameter of approximately six to eight millimeters (6-8 mm), or large enough to accommodate the shortened prosthetic valve 2, and an outer diameter of approximately seven to nine millimeters (7-9 mm), or small enough to fit within a docking sheath. The length of the valve chamber lumen can be configured to be longer than the length of the shortened prosthetic valve 2 so that the entire shortened prosthetic valve 2 can be accommodated therein. The length of the valve chamber lumen can be approximately twenty to fifty millimeters (20-50 mm).

[0140] In a further aspect, a smaller diameter valve chamber sheath 203 can be configured to be attached to the closed end of the distal end of the valve chamber 201 extending proximally to the VHPL system 1, making it possible to control the position of the valve chamber 201, and therefore the prosthetic valve 3, within the heart by manipulating the valve chamber sheath 203 on the proximal side of the VHPL system 1, i.e., the operator side.

[0141] It is contemplated that the valve chamber distal end 204 and the cylindrical portion of the valve chamber 201 may be made from one solid piece of material, or may be made from separate similar or dissimilar pieces of material that are optionally attached together. As shown in Figure 6, in any embodiment, the distal end of the valve chamber 201 may be configured with a central lumen to facilitate attachment to the valve chamber sheath 203 and rounded edges to prevent damage to surrounding tissue during operation.

[0142] The valve chamber sheath 203 can optionally be configured as a tube or a solid rod. In one aspect, the valve chamber sheath 203 can be configured to have multiple sections with varying stiffness along its length. Ideally, the valve chamber sheath 203 can be configured to have a rigid distal section within the valve chamber 201, followed by a flexible mid-section that can bend to facilitate steering of the VHPL system 1 within the patient's body, followed by another rigid section at the proximal end to provide pushability.

[0143] In one embodiment, the stent holder 207 can be configured to fit within the lumen of the valve chamber 201, which has the same outer diameter as the crimped prosthesis 2. The stent holder 207 is configured to attach to the distal tip of a smaller diameter stent holder sheath 206 that extends proximally to the VHPL system 1, allowing the position of the stent holder 207 within the valve chamber 201 to be controlled by manipulating the stent holder sheath 206 proximal to the VHPL system 1.

[0144] In one aspect, during operation, a stent holder 207 can be positioned distal to the crimped prosthesis 2 within the valve chamber 201. Thus, the valve chamber lumen can be configured to be longer than the combined length of the stent holder 207 and the crimped prosthesis 2.

[0145] The prosthetic valve 2 is intended to be crimped onto (around) the stent holder sheath 206 proximal to the stent holder 207 and loaded into the valve chamber 201. The valve stent 2 is then released from the valve chamber 201 by advancing the valve chamber sheath 203 distally relative to the stent holder 207. The stent holder 207 prevents distal movement of the prosthesis 2, and as the valve chamber 201 is moved distally, the prosthesis 2 is released from the valve chamber 201 starting from the proximal side of the valve stent 2 and ending at the distal side of the prosthesis 2.

[0146] 6 , the stent holder 207 can include recesses 208 configured to receive the tabs 8 of the extension members 7 of the prosthetic valve stent frame 3. In operation, the tabs 8 of the extension members 7 of the stent 3 are inserted into the recesses 208 on the stent holder 207, and the stent holder 207 is advanced into the valve chamber 201 to sandwich the tabs 8 between the recesses 208 and the inner wall of the valve chamber 201. The prosthesis 2 is crimped around the stent holder sheath 206, and the stent holder 207 is advanced to the distal end of the valve chamber 201 to load the crimped prosthesis 2 into the valve chamber 201. To release the prosthesis 2, the valve chamber sheath 203 is advanced distally while the position of the stent holder 207 is held fixed. In this embodiment, tabs 8 will engage stent holder 207 until valve chamber 201 is advanced sufficiently to reveal recess 208 in stent holder 207. Those skilled in the art will appreciate that this recess 208 serves as a safety mechanism to secure prosthesis 2 to VHPL system 1, allowing the prosthesis to be positioned and maneuvered within the heart using the controls of VHPL system 1 until selectively released.

[0147] In one embodiment, the valve chamber 201 can have a plurality of slits 205 approximately one to five millimeters (1-5 mm) long extending axially from the proximal end of the valve chamber 201. The slits 205 can be positioned in the valve chamber 201 to align with the holes 9 in the flared portion of the crimped stent 3, and following implantation of the DGF member 101, the subsequent DGF member tail 104 can be inserted through the slits 205 in the valve chamber 201, and the slits in the valve chamber can be designed to correspond to the number and position of the implanted DGF members 101.

[0148] In one exemplary embodiment, three DGF head members 102 can be initially implanted in the valve annulus, one at the medial commissure indicating the P3 position, one at the lateral commissure indicating the P1 position, and one at the center of the posterior annulus indicating the P2 position. The slits 205 are positioned along the periphery of the valve chamber 201 so as to align with the medial edge, lateral edge, and central holes 9 of the flared portion of the crimped prosthesis 2 when the crimped prosthesis 2 is loaded into the valve chamber 201, and the subsequent DGF tails 104 can be easily threaded through the slits 205 into the corresponding holes 9 of the flared portion and then onto the corresponding locking catheter 317 of the VHPL system 1.

[0149] In one embodiment, the VHPL system 1 is inserted into the patient's body, the DGF member tail 104 is tensioned to guide the valve chamber 201, and therefore the valve stent, to the operating position of the previously implanted DGF member 101 at the mitral valve annulus, and then the valve chamber sheath 203 is advanced to release the prosthesis from the atrial flared portion 4, and so on until the entire ventricular portion 5 of the prosthesis 2 is released.

[0150] In one embodiment, multiple locking catheters 317 are used to prevent proximal movement of the prosthesis 2 while tension is applied to the multiple DGF member tails 104 to pull the locking members 105 of the DGF member 101 through the atrial flare holes 9 of the prosthesis 2, thereby securing the prosthesis 2 in position over the native mitral valve annulus. The locking catheter 317, in one exemplary embodiment, is a composite sheath comprised of three distinct sections that facilitate fixation of the prosthesis 2. The proximal section of the locking catheter 318 can comprise, but is not limited to, a long, rigid metal tube. The metal tube 318 can span the majority of the delivery system and serve as a control for translating the locking catheter 317 through the handle 1 of the valve containment, positioning, and locking system. The intermediate section 319 of the locking catheter can comprise a flexible material to conform to the sharp bends of the deployment path. The flexible portion 319 of the locking catheter 317 can bend at a tight bend radius of approximately ninety degrees (90°) or more to enable locking along all portions of the valve annulus. The flexible portion 319 can be made from materials such as, but not limited to, metal, polymer, or rubber materials, and can optionally feature a coiled structure to allow for low bending stiffness and prevent the inner lumen from collapsing. The distal section 320 of the locking catheter can include a metal locking insert that engages the locking member 105 and the atrial flaring portion 4 of the prosthetic valve 2 to aid in securing the prosthetic valve 2 in the DGF body member 103.

[0151] In one exemplary embodiment, the locking catheter 317 may be attached to a handle for the operator to grasp and facilitate the fixation process.

[0152] In one embodiment, the suture tensioning mechanism can be configured to allow each of the DGF locking members 105 to be independently secured in position above the atrial flaring portion of the valve 4. In this embodiment, each of the individual DGF member tails 104 is controlled in the suture tensioning mechanism.

[0153] In one embodiment, the DGF tail tensioning mechanism includes a ratchet gear and turn knob assembly. The ratchet gear includes a round gear with rotatable teeth. A spring-loaded finger component engages the gear teeth. The gear teeth are uniform and both tooth slopes are symmetrical, allowing the teeth to move in both forward and backward directions. The stiffness of the spring-loaded finger and the slope of the gear teeth allow for controlled, incremental rotation of the gear, which in turn allows for controlled, incremental tensioning of the DGF member tail 104.

[0154] In another embodiment, the gear can be configured with an asymmetric ramp to allow for unidirectional rotation, thereby preventing the DGF tail member 104 from loosening during the procedure.

[0155] Additionally, in describing representative embodiments, the specification may present a method and / or process as a particular sequence of steps. However, the method or process should not be limited to the particular sequence of steps described unless the method or process relies on the particular order of steps described herein. As one skilled in the art would understand, other sequences of steps are possible. Accordingly, the particular order of steps described herein should not be construed as a limitation on the scope of the claims.

[0156] While the invention is susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not limited to the particular forms or methods disclosed, but on the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the appended claims.

Claims

1. 1. A heart valve leaflet replacement delivery system for implanting a prosthetic heart valve for the treatment of a diseased heart valve, comprising: a stent having a plurality of through-holes and a prosthetic valve including at least one prosthetic valve leaflet; a multi-stage, multi-lumen (MSML) delivery system including a dual guide and fixation (DGF) delivery system and a valve housing positioning and locking (VHPL) system cooperatively configured for advancing to an operating position, for delivering and implanting multiple DGF members to an operating position, and for guiding, delivering, and fixating a prosthetic valve to an operating position; a DGF delivery system configured to implant a plurality of DGF members into a native valve annulus to assist in guiding and fixating a prosthetic valve, each DGF member including: a head portion configured to be implanted into tissue; a body portion including a fixation mechanism; and a tail portion extending from the body portion proximally of the DGF delivery system to guide delivery of the prosthetic valve through the plurality of through-holes; a VHPL system configured to follow the tail portions of a plurality of DGF members to a desired implantation location of a previously implanted DGF member, gradually release the prosthetic valve from a contracted state from a proximal-most portion of the prosthetic valve to a distal-most portion of the prosthetic valve, and secure the prosthetic valve to the DGF members via the securement mechanism; The VHPL system comprises: a stent holder sheath for holding the artificial valve; a valve chamber sheath surrounding the stent holder sheath and having a valve chamber, wherein the entire prosthetic valve is contained within the valve chamber in a contracted delivery state, and the valve chamber sheath is advanceable distally relative to the stent holder sheath to deploy the prosthetic valve; a stent of the prosthetic valve engages with the stent holder sheath to guide, expand, and secure the prosthetic valve in place before selectively removing the prosthetic valve from the stent holder sheath.

2. 10. The system of claim 1, A system characterized in that each head portion is configured as a spiral formed from a wire having a diameter of 0.25 to 1.0 mm, having a length of 4 to 10 mm and a diameter of 2 to 5 mm, and each DGF member further comprises a stabilizing member configured as a straight wire having a diameter of 0.25 to 1.0 mm extending axially through the center of the spiral, with its sharp tip extending 1 to 3 mm beyond the end of the spiral.

3. 3. The system of claim 2, A system characterized in that each body portion is attached to a respective head portion and configured to resist separation, each body portion is configured to have a plurality of engagement structures designed to engage with the DGF delivery system, and includes a plurality of passages, at least one passage configured to secure the fixation mechanism to the body portion, and at least one passage for attaching the stabilization member.

4. 10. The system of claim 1, the fixation mechanism comprises at least one locking member and at least one tether, the tether configured to attach the at least one locking member to the body portion, and the at least one locking member configured to pass through a through hole of the prosthetic valve in only one direction.

5. 5. The system of claim 4, A system wherein at least the locking member is configured to have a plurality of radially compressible legs that flare outwardly to form a cone or dome shape.

6. 10. The system of claim 1, The VHPL system further comprises: a stent holder held by the stent holder sheath, the stent holder being received within the valve chamber and engaging a stent of the prosthetic valve to prevent the prosthetic valve from moving while the prosthetic valve is deployed and expanded within its native annulus after the valve chamber sheath is advanced; a plurality of locking catheters disposed proximally of the stent holder and extending proximally to the VHPL system; a multi-lumen guide sheath that houses the stent holder sheath and a locking catheter.

7. 10. The system of claim 1, The VHPL system is characterized in that it is configured to receive trailing tails of DGF members implanted prior to delivery of the valve with multiple locking catheters positioned proximal to a shortened prosthetic valve within the VHPL system.

8. The system according to any one of claims 1 to 7, The system, characterized in that the proximal end of the VHPL system is configured with a suture tensioning mechanism that individually and selectively applies tension to the tail portions to guide the delivery and fixation of the prosthetic valve.

9. 7. The system of claim 6, A system characterized in that the lower flared portion of the stent of the artificial valve has at least one feature configured to selectively engage with the stent holder so that the artificial valve can be guided, expanded, and secured in position against a plurality of DGF members before selectively removing the artificial valve from the stent holder.

10. The system according to any one of claims 1 to 7, A system characterized in that each head member is configured to be implanted through an upper flared portion of the prosthetic valve, and multiple additional DGF members are implanted on top of the prosthetic valve in an operating position after being fixed in place by multiple previously implanted DGF members having DGF locking members.

11. In the system described in claim 1, The system is characterized in that the stent of the prosthetic valve includes a lower flared portion configured to selectively engage with the stent holder sheath, allowing the prosthetic valve to be guided, deployed, and secured in position against a plurality of DGF members before selectively removing the prosthetic valve from the VHPL system.

12. In the system described in claim 11, the stent of the prosthetic valve includes at least one elongated member extending from the lower flared portion and a tab at a distal tip of the elongated member configured to be received within at least one recess in a stent holder of the stent holder sheath distal to the prosthetic valve when the prosthetic valve is crimped into the valve chamber; the prosthetic valve can be selectively attached to the VHPL system by inserting the stent holder into the valve chamber such that at least one tab is placed into at least one recess in the stent holder, and the tab is sandwiched between an inner wall of the valve chamber and at least one recess in the stent holder; the prosthetic valve can be selectively removed from the VHPL system by advancing the valve chamber distally relative to the stent holder to expose the at least one recess and release the tab.

13. A system as described in claim 6 or 9, characterized in that the artificial valve is contracted around a stent holder sheath proximal to the stent holder and loaded into the valve chamber, and the valve chamber can be subsequently released by advancing the valve chamber sheath distally relative to the stent holder, allowing the stent to expand within the native valve annulus without being released from the stent holder sheath.

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