Patent Publication Number: US-2023149168-A1

Title: Mitral or tricuspid repair systems with multi-directional anchors

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of U.S. patent application Ser. No. 15/923,677, filed Mar. 16, 2018, entitled “MITRAL OR TRICUSPID REPAIR SYSTEMS WITH MULTI-DIRECTIONAL ANCHORS”, which claims the benefit of priority under 35 U.S.C. 119(e) to the filing date of U.S. Provisional Patent Application 62/472,633 filed Mar. 17, 2017, entitled, “IMPROVED MITRAL OR TRICUSPID VALVE REPAIR SYSTEM,” the contents of both of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to implantable prosthetic devices. More specifically, the disclosure is directed to an improved prosthetic device implantable by catheter for the treatment of mitral or tricuspid regurgitation. 
     BACKGROUND 
     Mitral Regurgitation is a valvular dysfunction that causes blood volume to flow during systole (during left ventricular contraction) from the left ventricle to the left atrium. In contrast, in a healthy heart, this direction of flow is blocked by the mitral valve. The reverse flow during systole causes pressure to rise in the left atrium, and maintaining a normal cardiac output results in an increased pressure in the left ventricle. 
     Treating patients with MR (mitral regurgitation) or TR (tricuspid regurgitation) could require valve replacement in order to reduce or eliminate the regurgitation. For many years, the commonly accepted treatment was surgical repair or replacement of the native valve during open heart surgery. In recent years, a trans-vascular technique has been developed for introducing and implanting a prosthetic heart valve using a flexible catheter in a manner that is less invasive than open heart surgery. 
     In the trans-vascular technique, a prosthetic valve is delivered to the target site (e.g., aortic valve, mitral valve, tricuspid valve, or other valve) through a catheter while the valve is crimped to a low diameter shaft. The valve is then expanded/deployed to a functional size when it is located in the correct position. Examples of such prosthetic valves, and related processes for delivering the valves through a catheter, are described in U.S. Pat. No. 8,518,107, the content of which is hereby incorporated by reference in its entirety. 
     Advancing the catheter to the target site can be achieved through: (a) The vascular system where a catheter is advanced from the femoral vein/artery, or any other blood vessel that allows access to the target site; (b) Trans-apically where a catheter is advanced through a small incision made in the chest wall and then through the apex; or (c) Trans-atrially where a catheter is advanced through a small incision made in the chest wall and then through the left or right atrium. 
     SUMMARY 
     Embodiments herein are directed to various prosthetic valve ring assemblies for use in repairing cardiac valves suffering from, for example, mitral or tricuspid regurgitation. 
     A prosthetic valve ring assembly is described herein. In certain embodiments, the prosthetic valve ring assembly can include an outer tube that includes a plurality of windows; and a plurality of anchors positioned inside the outer tube and about a perimeter of the outer tube. The plurality of anchors are configured to be emitted from the plurality of windows to anchor the prosthetic valve ring assembly to annulus tissue of a patient. In some embodiments, the anchors are configured to be emitted in different directions. For example, a first portion of the anchors are configured to be emitted to a ventricular side of the annulus tissue of the patient and a second portion of the anchors are configured to be emitted to an atrial side of the annulus tissue of the patient. 
     In some embodiments, the anchors are created using a laser cutting technique. In an embodiment, the laser cutting technique includes cutting according to a laser cut pattern to define a plurality of windows through which the plurality of anchors are configured to be emitted. 
     In some embodiments, the prosthetic valve ring assembly further includes a closure device configured to lock a distal side and a proximal side of the prosthetic valve ring assembly. In some embodiments, the prosthetic valve ring assembly further includes a post adjustment mechanism that includes a flexible connection configured to move an anterior portion of the prosthetic valve ring assembly relative to a posterior portion of the prosthetic valve ring assembly, thereby changing at least one of a size and a geometry of the prosthetic valve ring assembly. 
     In some embodiments, the prosthetic valve ring assembly further includes a closure device configured to lock a distal side and a proximal side of the prosthetic valve ring assembly; and an unlocking mechanism configured to unlock the closure device, thereby enabling repositioning or retrieval of the prosthetic valve ring assembly from a patient through a catheter. In some embodiments, the prosthetic valve ring assembly further includes one or more bumps positioned on a perimeter of the prosthetic valve ring assembly and configured to apply additional pressure to trigones of the annulus tissue of the patient, thereby providing improved anchoring of the prosthetic valve ring assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects, features, benefits and advantages of the embodiments described herein will be apparent with regard to the following description, appended claims, and accompanying drawings where: 
         FIG.  1    illustrates a top view of an improved mitral valve ring, in accordance with at least one embodiment of the present disclosure. 
         FIG.  2    illustrates a side view of an improved mitral valve ring, in accordance with at least one embodiment of the present disclosure. 
         FIG.  3    illustrates a bottom view of an improved mitral valve ring, in accordance with at least one embodiment of the present disclosure. 
         FIG.  4    illustrates another side view of an improved mitral valve ring, in accordance with at least one embodiment of the present disclosure. 
         FIG.  5    illustrates a ring laser cut pattern, in accordance with at least one embodiment of the present disclosure. 
         FIG.  6    illustrates a posterior anchor zone with anchors activated by passive anchor stop features, in accordance with at least one embodiment of the present disclosure. 
         FIG.  7    illustrates a posterior anchor zone with anchors activated by active anchor stop features, in accordance with at least one embodiment of the present disclosure. 
         FIG.  8    illustrates the 3D shape of posterior and/or anterior zone anchors, in accordance with at least one embodiment of the present disclosure. 
         FIG.  9    illustrates the angles of posterior and/or anterior zone anchors, in accordance with at least one embodiment of the present disclosure 
         FIG.  10    illustrates a perspective view of a closure device, in accordance with at least one embodiment of the present disclosure. 
         FIG.  11    illustrates a cross-sectional view of a closure device, in accordance with at least one embodiment of the present disclosure. 
         FIG.  12    illustrates another perspective view of a closure device, in accordance with at least one embodiment of the present disclosure. 
         FIG.  13    illustrates a top view of a mitral valve ring that includes anchors adjacent to the closure device area, in accordance with at least one embodiment of the present disclosure. 
         FIG.  14    illustrates an isometric view of a mitral valve ring that includes anchors adjacent to the closure device area, in accordance with at least one embodiment of the present disclosure. 
         FIG.  15    illustrates a top side view of a mitral valve ring that includes anchors adjacent to the closure device area, in accordance with at least one embodiment of the present disclosure. 
         FIG.  16    illustrates a top view of an alternative ring assembly including bumps in the trigones region, in accordance with at least one embodiment of the present disclosure. 
         FIG.  17    illustrates a top view of an alternative ring assembly including bumps in the trigones region with anchors, in accordance with at least one embodiment of the present disclosure. 
         FIG.  18    illustrates a side view of an alternative ring assembly including bumps in the trigones region with anchors, in accordance with at least one embodiment of the present disclosure. 
         FIG.  19    illustrates another side view of an alternative ring assembly including bumps in the trigones region with anchors, in accordance with at least one embodiment of the present disclosure. 
         FIG.  20    illustrates yet another side view of an alternative ring assembly including bumps in the trigones region with anchors, in accordance with at least one embodiment of the present disclosure. 
         FIG.  21    illustrates an alternative mitral valve ring with one or more post adjustment mechanisms, in accordance with at least one embodiment of the present disclosure. 
         FIG.  22    illustrates another alternative mitral valve ring with one or more post adjustment mechanisms, in accordance with at least one embodiment of the present disclosure. 
         FIG.  23    illustrates a laser cut layout for a tricuspid ring, in accordance with at least one embodiment of the present disclosure. 
         FIG.  24    illustrates a 3D shape for a tricuspid ring, in accordance with at least one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure is not limited to the particular systems, devices and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope. 
     As used in this document, the singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Nothing in this disclosure is to be construed as an admission that the embodiments described in this disclosure are not entitled to antedate such disclosure by virtue of prior invention. As used in this document, the term “comprising” means “including, but not limited to.” 
     When implanting a replacement valve (e.g., an aortic valve, mitral valve, tricuspid valve, or other valve), the replacement valve can include a prosthesis attachment. The prosthesis can be configured to secure the replacement valve in a patient&#39;s heart. An example of such a prosthesis is the AMEND™ Mitral Valve Repair Annuloplasty ring developed by Valcare Medical. The AMEND™ ring is a D-shaped ring configured to emulate the total valve replacement for patients who suffer from Mitral Regurgitation (MR, as described above). Additional detail related to prosthetic valves for mitral or tricuspid valve replacement can be found in U.S. patent application Ser. No. 14/891,189 entitled “Transcatheter Prosthetic Valve for Mitral or Tricuspid Valve Replacement,” filed May 22, 2013, the content of which is incorporated herein by reference in its entirety. 
     As described herein, a prosthetic ring can be configured to include various anchor zones on a posterior side. The anchor zones are positioned to emit anchors in different directions and/or angles from two or more windows on the cross section of the ring. For example, a portion of the anchors may be emitted to the ventricular side of the annulus tissue, and a portion of the anchors may be emitted to the atrial side of the annulus tissue. Such an arrangement can provide for improved anchoring of the ring into the annulus tissue as compared to conventional mitral valve rings. 
     It should be noted that, while the following detailed description of the figures is directed to a prosthetic ring configured to anchor a replacement valve such as the AMEND™ ring as described above, the techniques, ideas, and processes described herein can be applied to any mitral valve ring. 
       FIGS.  1 - 4    illustrate various views of an improved mitral valve ring  100 . In certain implementations, the ring  100  can include posterior side anchor zones that are configured to emit anchors in different directions and/or angles from two or more windows on the cross section of the ring. In some examples, a portion of the anchors are configured to be emitted to the ventricular side of a patient&#39;s annulus tissue, while a second portion of the anchors are configured to be emitted to the atrial side of the annulus tissue. Thus, two or more anchors can be emitted from one window in different directions. 
       FIG.  1    illustrates a top view of the ring assembly  100 . The ring assembly  100  can include an outer tube  102  that defines the shape of the ring assembly. The outer tube  102  can include one or more windows about its circumference as well as one or more windows in its cross-section. One or more anchors can be positioned and configured to extend through these windows. The ring assembly  100  can also include a set of posterior zone anchors  110 . As shown in  FIG.  1   , the posterior zone anchors  110  are generally positioned on the posterior of the ring assembly  100 . The ring assembly  100  can further include anterior zone anchors  120  generally positioned on the anterior of the ring assembly. 
     Each anchor zone (including both posterior zone anchors  110  and anterior zone anchors  120 ) can include atrial side anchors  111  as well as ventricular side anchors  112  (not shown in  FIG.  1    but illustrated in, for example,  FIG.  2   ). As noted above, in certain implementations, upon insertion of the ring assembly  100 , the atrial side anchors  111  can be configured to be emitted into the atrial side of the patient&#39;s annulus tissue and the ventricular side anchors can be configured to be emitted into the ventricular side of the patient&#39;s annulus tissue. 
     As further shown in  FIG.  1   , the ring assembly  100  can include a closure device  150 . The closure device  150  can be configured to lock a distal end of the ring assembly  100  to a proximal end of the ring assembly. The closure device  150  can also be designed and configured to removably attach to a delivery system for the valve replacement implant. For example, in certain implementations, the closure device  150  can include a pivot pin  153  that is configured to removably attach the ring assembly  100  to a delivery device as well as provide for rotation of the ring assembly when emitted from the delivery device. For example, the pivot pin  153  can be configured to provide for 90 degrees of rotation of the ring assembly  100 . In other implementations, the pivot pin can be configured to provide for additional ranges of rotation such as 75-105 degrees of rotation, 60-120 degrees of rotation, and other similar ranges of rotation. 
     The ring assembly  100  can further include a set of pins  103 . The pins  103  can be positioned and configured to connect the outer tube  102  to the closure device  150 . In certain implementations, the pins  103  can be further positioned and configured to provide for routing of sutures as well as to function as a pulley while providing for rotation of a suture (e.g., 90 degree rotation) with minimal friction. 
       FIG.  2    illustrates a first side view of the ring assembly  100 , shown from the posterior and further illustrating the closure device  150 .  FIG.  2    further illustrates the alternate emitting directions of the atrial side anchors  111  in an outward and upward direction relative to a plane of the ring assembly  100  and the ventricular side anchors  112  in an outward and downward direction relative to the plane of the ring assembly  100 . 
       FIG.  3    illustrates a bottom view of the ring assembly  100 . In contrast to  FIG.  1   ,  FIG.  3    illustrates the ventricular side anchors  112 .  FIG.  3    further illustrates additional anterior side anchors  120  that were obscured from view in  FIG.  1   . 
     Additionally, in certain embodiments, various anchors can be configured such that portions of the anchors can cross one another in different directions, thereby creating a closed loop and stapling effect of the tissue. For example, anchors  121  and  122  as shown in  FIG.  3    are configured to cross one another in different directions, thereby having a stapling effect on the adjacent tissue, securely locking the ring assembly  100  into position. 
       FIG.  4    illustrates a second side view of the ring assembly  100 , shown further illustrating the crossing anchors  121  and  122 . 
     The raw materials of the ring assembly  100  and various components included therein can be selected from various materials, such as various polymers, shape memory materials such as Nitinol, metals such as stainless steel, or other similar materials safe for implanting into or adjacent to living tissue. In certain implementations, the ring assembly  100  can include a combination of two or more different materials, such as stainless steel 316/316L and Nitinol. This combination is provided by way of example only, and other materials can be used alternately or additionally. 
     In order to create the ring assembly  100  as described above, the outer tube  102  can be manufactured such that multiple windows are defined. The windows can be positioned to facilitate deployment of the various anchors as described above.  FIG.  5    illustrates an example cut pattern  200  for creating the outer tube  102  as described above. For example, the pattern  200  shows an example cut pattern of a ring tube  202  with several windows  204 A,  204 B,  204 C and  204 D that allow deployment of anchors in different directions. For example, anchors can be emitted in the atrial side from windows  204 D, and anchors can be emitted from the ventricular side from windows  204 C. 
     In an alternate embodiment, more than one anchor can be emitted from one window with one or more anchors in the atrial side and one or more anchors in ventricular side. In another embodiment, one or more anchors can be emitted from different windows in the same direction. For example, two windows (e.g.,  204 A and  204 B) can be configured to provide for simultaneous deployment of anchors towards the ventricular side. 
       FIGS.  6  and  7    illustrate example cut patterns (e.g., laser cut patterns) for the anterior and/or posterior zone anchors such as posterior zone anchors  110  and anterior zone anchors  120  as described above. Additionally, as noted above, anchors can be emitted in both the atrial and ventricle directions, such as atrial anchors  111  and ventricle anchors  112  as described above. 
     To achieve such a configuration, cut pattern  300  as shown in  FIGS.  6  and  7    can be used to create one or more anchor zones  302 . The cut pattern can define a set of atrial anchors  304  and a set of ventricle anchors  306  within the anchor zone  302 . The cut pattern  300  can also define an anchor stop feature  308 . The anchor stop feature  308  can be configured to lock the anchor zone  302  into, for example, the outer tube of a ring assembly to prevent unintentional movement of the anchor zone. 
     In certain implementations, the anchor stop feature  308  can be a passive feature that is activated as a result of a force exerted on the anchor zone  302  (e.g., a pulling force) causing a bending or other change to the geometry of the anchor stop feature  308 . In other embodiments, the anchor stop feature  308  can include an associated activation mechanism that facilitates activation of the anchor stop feature. For example, the activation mechanism can be an activation pulley that prevents the anchor stop feature  308  from bending of otherwise deforming such that a portion of the anchor stop feature exits through a corresponding hole on the outer tube of the ring assembly. Such an arrangement can lock the anchor zone  302  into position as the anchor stop feature  308  prevents any relative movement. In some examples, pulling on the activator mechanism and removing it from the designated location allows the anchor stop feature  308  to bend and allows relative movement of the anchor zone  302  in relation to the outer tube of the ring assembly. 
     In certain implementations, the anchor stop feature  308  can be located in either the ventricular side or atrial side of the anchor zone  320  and/or outer tube. Additionally, in various embodiments, the anchor stop feature  308  can be positioned in any location along the anchor zone  302 . The position as shown in  FIGS.  6  and  7    is shown by way of example only. 
     It should be noted that laser cutting the ring assemblies as described herein is provided by way of example only, and additional manufacturing techniques can be used. For example, a stamping process can be used to stamp the cut patterns as described above. 
       FIGS.  8  and  9    illustrate the cut patterns  300  as described above in regard to  FIGS.  6  and  7    that have been, for example, heat treated and to include various bends and curves, thereby defining a specific three-dimensional shape for the anchor zones  302 . For example, the anchor zones  302  can be heat-treated and bent at an angle selected from a range of angles. For example, in certain implementations the range of angles can be from zero degrees (e.g., no additional bending) to 135 degrees. As shown in  FIGS.  8  and  9   , the ventricle anchors  306  can be heat-treated to 45 degrees, and the atrial anchors  304  can be heat-treated to 60 degrees. 
     In addition, the anchor zone can have a 3D shape that fits the zone location in the final ring assembly. For example, the posterior anchor zones can be curved to fit the posterior curvature of the ring assembly, and the anterior anchor zones can be curved to fit the anterior curvature of the ring assembly. 
     It should be noted that heat-treated bending and curving is provided by way of example only. Depending upon the type of material being used and the design of the individual components such as the anchor zones, alternative bending and curving techniques can be used to form the anchor zones to the geometry of the final ring assembly. 
       FIGS.  10 - 12    illustrate detailed views of a closing mechanism  400  for a ring assembly, such as closing mechanism  150  as described above in regard to ring assembly  100 . In certain implementations, a closing mechanism can include a female component configured to lock to a male component. For example,  FIGS.  10 - 12    illustrate various views and embodiments of the female component  402 . As shown in  FIG.  10   , the female component  402  can include a locking mechanism for releasably attaching to a male component or cup  404 . 
     The female component  402  can further include an unsnapping pin  406 . The unsnapping pin can be positioned and configured to unsnap or otherwise disconnect the female component  402  from the cup  404  of the ring assembly. Additionally, the female component  402  can include a pivot pin  408  for attaching the female component to an outer tube of the ring assembly. Additionally, the pivot pin  408  can be configured to function as an interface between the ring assembly and a delivery system, similar to pins  103  as described above. 
       FIG.  11    illustrates a cross-section of the female component  402 . As shown in the cross-sectional view, the female component  402  can include a disk  410 . The disk  410  can be positioned to abut an end of the cup  404  when inserted into the female component  402  to provide for locking of the male component to the female component. In some examples, the disk  410  can be held in position with a cover. 
       FIG.  12    illustrates a view of the locking mechanism  400  with a portion of the cup  404  removed, showing additional detail of the unsnapping pin  406 . As shown in  FIG.  12   , the unsnapping pin  406  can be designed with two individual fingers extending from a central point such that, upon exerting a force (e.g., a squeezing force) upon an end of the fingers opposite the central point, the fingers deflect about the point. Upon deflection of the unsnapping pin  406 , the unsnapping pin can be removed, thereby releasing the male component (e.g., cup  404 ) from the female component  402 . 
     In certain implementations, the disk  410  and the unsnapping pin  406  can be made from a shape memory alloy such as Nitinol. In some example, the other components of the female component can be made from various metallic materials such as stainless steel, aluminum, Nitinol, and titanium. 
     As noted above, the cup  404  and the female component  402  are attached together with the unsnapping pin  406 . If properly inserted and positioned, the unsnapping pin  406  can visually verify that the two parts are well-attached and cannot open unintentionally. Conversely, upon activation of the unsnapping pin  406  by pulling it in a specific direction, it allows separation of the two components. By doing this, the ring close structure is compromised and the closed shape becomes open and allows retrieval of the implant into the delivery system. 
     In some embodiments, the female component  402  can have one or more gold markers  412  that provide for confirmation of locking of the cup  404  and the female component during a clinical procedure. 
       FIGS.  13 - 15    illustrate various views of a ring assembly  500 . Similar to ring assembly  100  as described above, the ring assembly  500  can include an outer tube, a set of posterior zone anchors, a set of anterior zone anchors, and a closure device  150 . However, the ring assembly  500  as shown in  FIGS.  13 - 15    can further include additional anchors  502  and  504  positioned adjacent to the closure device and configured to improve attachment of the ring assembly  500  to the patient&#39;s posterior annulus tissue. In certain implementations, the anchors  502  and  504  can be configured to be emitted in different directions and/or angles from one or more windows on the cross section of the outer tube in the area of the closure device. In some examples, one or more additional anchors can be configured to be emitted to the ventricular side of the annulus tissue, and one or more of the additional anchors can be configured to be emitted to the atrial side of the annulus tissue. In some embodiments, two or more additional anchors can be configured to be emitted from one window in the outer tube in different directions to each other. In some embodiments, the anchors can include additional features such as hooks, barbs, or other similar features for increasing durability and preventing detachment. 
     In certain implementations, a ring assembly can further include bumps or other similar protrusions in the trigones area of the ring assembly. For example, as shown in  FIGS.  16  and  17   , a ring assembly  600  (shown without anchors in  FIG.  16    and with anchors in  FIG.  17   ) can include bumps  602  and  604  positioned on the portion of the ring assembly that will be adjacent to the fibrous trigones region of a patient&#39;s heart. The bumps  602  and  604 , or other similar protrusions or added features, can provide for added contact between the ring assembly  600  and the patient&#39;s trigones region of the annulus tissue. In some implementations, achieving such contact can provide for better contact between the ring assembly  600  and the annulus tissue as compared to a ring assembly without the bumps in the trigones region. Similar to the ring assemblies as described above, various patterns and directions of anchors can be used to improve anchoring the ring assembly  600  to the annulus tissue as well. 
     In certain implementations, additional anchors can be beneficial for providing additional anchoring points for a ring assembly. In some examples, a single anchor or set of additional anchors can be emitted from an existing window in an outer tube of a ring assembly providing a more robust anchoring point as compared to the curved anchors as described above. For example, as shown in  FIGS.  18 - 20   , ring assembly  700  can include additional anchors configured to provide a more robust anchoring point. As shown in  FIG.  18   , an additional anchor  702  can be emitted from a window for providing an additional anchoring point on the atrial side of the ring assembly  700 .  FIG.  19    illustrates an additional anchor  704  being emitted from a similar window for providing an additional anchoring point on the ventricular side of the ring assembly  700 .  FIG.  20    illustrates a set of two or more additional anchors emitting from a single window. In this example, additional anchors  702  and  704  provide additional anchoring into the atrial side and the ventricular side of the ring assembly  700  respectively. 
     In some implementations, resizing the ring assembly can be desirable as a single ring assembly can accommodate an additional range of patients and valve sizes. For example, a ring assembly can include a flexible connection that is laser cut from a similar material as the outer tube of the ring assembly. The flexible connection can be configured to contract and/or expand to allow for changing the size of the ring before, during, and/or after implantation of the ring assembly. In some examples, the ring assembly can be manufactured from separate segments or components that are configured to be attached together with a mechanism or device that controls expansion and/or contraction of each side of a ring assembly separately or simultaneously. 
       FIG.  21    illustrates a ring assembly  800  that is configured to be resizable as described above. The ring assembly  800  can include an anterior portion  802  and a posterior portion  804 . The anterior portion  802  and the posterior portion  804  can be connected together with a set of adjustable components  806  and  808 . The adjustable components  806  and  808  can be made from a flexible material configured to expand and/or contract, thereby changing the overall size of the ring assembly  800 . In certain implementations, the anterior portion  802  and/or the posterior portion  804  can include an adjustment mechanism that is configured to interact with the adjustable components  806  and  808  to change the size, shape and/or geometry of the ring assembly  800 . For example, the adjustment mechanisms can include a ratcheting feature that is configured to interact with the adjustable components  806  and  808  to change the size of the ring assembly  800 . 
     It should be noted that a ratcheting feature is provided by way of example only. Additional adjustment mechanisms such as friction-based holding devices, snap-based devices, winding devices, and other similar adjustment devices can be used. Additionally, it should be noted that two adjustable components  806  and  808  are shown by way of example. In additional implementations, various numbers of adjustable components can be used. For example, a single adjustable component can be included on one side of the ring assembly. 
       FIG.  22    illustrates a ring assembly  810  that is configured to be resizable, similar to ring assembly  800  as described above. However, the ring assembly  810  can include an anterior portion  812  and two posterior portions  814  and  815 . Such an arrangement can provide for additional flexibility and sizing options when implanting the ring assembly  810 . 
     In some implementations, the anterior portion  812  can be connected to the posterior portion  815  with a first adjustable component  816 . Similarly, the anterior portion can be connected to the posterior portion  814  with a second adjustable component  818 . The posterior portions  814  and  815  can be configured to releasably attach to one another via a closure device such as closure device  150  as described above. 
     The ring assemblies as described above can be designed and shaped for various functions such as mitral valve replacement. However, a similar ring assembly can be designed and constructed for tricuspid valve replacement as well. However, a tricuspid ring can be designed with additional features such as a release zone positioned on the ring assembly at a location that will be adjacent to a patient&#39;s atrioventricular node or valves. 
       FIGS.  23  and  24    illustrate an example tricuspid ring assembly  900  ( FIG.  23    illustrating a 3D view of the assembly, while  FIG.  24    illustrates a flat cut pattern view). The outer tube  902  of the ring assembly  900  can include multiple windows through which anchors can be emitted as described above. However, the ring assembly  900  can further include a release zone  904  configured and positioned at a location that will be adjacent to a patient&#39;s atrioventricular node or valves when the ring assembly is implanted. 
     In certain implementations, the release zone  904  does not have any anchors. Rather, the alternate shape and profile of the release zone provides for interference between the ring assembly  900  and the patient&#39;s atrioventricular node or valves, thereby securing the ring assembly in position. 
     In the above detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be used, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein. 
     The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, compositions or biological systems, which can, 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. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (for example, bodies of the appended claims) are generally intended as “open” terms (for example, the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” et cetera). While various compositions, methods, and devices are described in terms of “comprising” various components or steps (interpreted as meaning “including, but not limited to”), the compositions, methods, and devices can also “consist essentially of” or “consist of” the various components and steps, and such terminology should be interpreted as defining essentially closed-member groups. It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. 
     For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (for example, “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. 
     In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (for example, the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, et cetera” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (for example, “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, et cetera). In those instances where a convention analogous to “at least one of A, B, or C, et cetera” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (for example, “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, et cetera). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. 
     As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, et cetera. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, et cetera. As will also be understood by one skilled in the art all language such as “up to,” “at least,” and the like include the number recited and refer to ranges that can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. 
     Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.