Patent Publication Number: US-2021161661-A1

Title: Prosthetic heart valve delivery systems and methods

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 16/282,885, filed Feb. 22, 2019, which claims the benefit of U.S. Provisional Patent Application Ser. No. 62/633,932, filed Feb. 22, 2018, the entire teachings of each of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to systems and methods for delivery a medical device, such as a prosthetic heart valve. More particularly, it relates to minimally invasive, transcatheter-based systems and methods for delivering a medical device, such as a prosthetic mitral valve via a transseptal approach. 
     A human heart includes four heart valves that determine the pathway of blood flow through the heart: the mitral valve, the tricuspid valve, the aortic valve, and the pulmonary valve. The mitral and tricuspid valves are atrio-ventricular valves, which are between the atria and the ventricles, while the aortic and pulmonary valves are semilunar valves, which are in the arteries leaving the heart. The tricuspid valve, also known as the right atrio-ventricular valve, is a tri-leaflet valve located between the right atrium and the right ventricle. The mitral valve, also known as the bicuspid or left atrio-ventricular valve, is a bi-leaflet valve located between the left atrium and the left ventricle. 
     As with other valves of the heart, the mitral valve is a passive structure in that it does not itself expend any energy and does not perform any active contractile function. The mitral valve includes an annulus that provides attachment for the two leaflets (anterior leaflet and posterior leaflet) that each open and close in response to differential pressures on either side of the valve. The leaflets of the mitral valve are dissimilarly shaped. The anterior leaflet is more firmly attached to the annulus, and is somewhat stiffer than the posterior leaflet (that is otherwise attached to the more mobile posterior lateral mitral annulus). The anterior leaflet protects approximately two-thirds of the valve. The anterior leaflet takes up a larger part of the annulus and is generally considered to be “larger” than the posterior leaflet (although the posterior leaflet has a larger surface area). In a healthy mitral valve, then, the anterior and posterior leaflets are asymmetric. 
     Ideally, the leaflets of a heart valve move apart from each other when the valve is in an open position, and meet or “coapt” when the valve is in a closed position. Problems that may develop with valves include stenosis in which a valve does not open properly, and/or insufficiency or regurgitation in which a valve does not close properly. Stenosis and insufficiency may occur concomitantly in the same valve. The effects of valvular dysfunction vary, with regurgitation or backflow typically having relatively severe physiological consequences to the patient. 
     Diseased or otherwise deficient heart valves can be repaired or replaced using a variety of different types of heart valve surgeries. One conventional technique involves an open-heart surgical approach that is conducted under general anesthesia, during which the heart is stopped and blood flow is controlled by a heart-lung bypass machine. 
     More recently, minimally invasive approaches have been developed to facilitate catheter-based implantation of the valve prosthesis on the beating heart, intending to obviate the need for the use of classical sternotomy and cardiopulmonary bypass. In general terms, an expandable prosthetic valve is compressed about or within a catheter, inserted inside a body lumen of the patient, such as the femoral artery, and delivered to a desired location in the heart. 
     The heart valve prosthesis employed with catheter-based, or transcatheter, procedures generally includes an expandable frame or stent that supports a valve structure having a plurality of leaflets. The frame can be contracted during percutaneous transluminal delivery, and expanded upon deployment at or within the native valve. One type of valve stent can be initially provided in an expanded or uncrimped condition, then crimped or compressed about a balloon portion of a catheter. The balloon is subsequently inflated to expand and deploy the prosthetic heart valve. With other stented prosthetic heart valve designs, the stent frame is formed to be self-expanding. With these systems, the valved stent is crimped down to a desired size and held in that compressed state within a sheath for transluminal delivery. Retracting the sheath from this valved stent allows the stent to self-expand to a larger diameter, fixating at the native valve site. In more general terms, then, once the prosthetic valve is positioned at the treatment site, for instance within an incompetent native valve, the stent frame structure may be expanded to hold the prosthetic valve firmly in place. One example of a stented prosthetic valve is disclosed in U.S. Pat. No. 5,957,949 to Leonhardt et al., which is incorporated by reference herein in its entirety. Another type of valve stent can be initially provided in an expanded or uncrimped condition, then crimped or compressed about a balloon of a balloon catheter. The balloon is subsequently inflated to expand and deploy the prosthetic heart valve. 
     The actual shape and configuration of any particular transcatheter prosthetic heart valve is dependent, at least to some extent, upon the valve being replaced or repaired (i.e., mitral valve, tricuspid valve, aortic valve, or pulmonary valve). The stent frame must oftentimes provide and maintain (e.g., elevated hoop strength and resistance to radially compressive forces) a relatively complex shape in order to achieve desired fixation with the corresponding native anatomy. Moreover, the stent frame must have a robust design capable of traversing the tortuous path leading to the native valve annulus site. These design features can give rise to delivery obstacles such as difficulties in precisely locating and rotationally orienting the prosthetic valve relative to the native annulus. 
     Anatomical constraints can also present difficult delivery obstacles. For example, the mitral valve controls the flow of blood from the left atrium to the left ventricle. There are various minimally invasive treatments that can be done on the mitral valve and related anatomy. For example, with one procedure to gain transcatheter access to the mitral valve, the delivery device is directed through the vena cava to the right atrium, and then to the left atrium via a puncture in the atrial septum (the wall of tissue that separates the left atrium from the right atrium). This procedure to access the mitral valve from the left atrium is sometimes referred to as a transseptal approach. Regardless, once located in the left atrium, it can be difficult to manipulate the delivery system within the confines of the left atrium so as to align the prosthetic valve with the native annulus. Similar concerns are presented by other transcatheter valve delivery procedures using other approaches and/or in access other valves of the heart. 
     SUMMARY 
     The inventors of the present disclosure recognized that a need exists for transcatheter delivery devices and methods that address one or more of the above-mentioned problems. 
     Some aspects of the present disclosure relate to methods of delivering a prosthetic heart valve. The methods including advancing a distal region of a guide member assembly into a heart of a patient. The distal region is docked to native anatomy of the heart. A delivery device, including a collapsed prosthetic heart valve, is advanced over the docked guide member assembly. The collapsed prosthetic heart valve is located at an implantation site. The prosthetic heart valve is deployed from the delivery device, and then the delivery device is removed from the patient. At least a portion of the guide member assembly is removed from the patient. In some embodiments, the docking structure is docked to one or more of native mitral valve leaflets, chordae in the left ventricle, or walls of the left ventricle as part of a transseptal mitral valve delivery procedure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic sectional illustration of a mammalian heart having native valve structures; 
         FIG. 2  is a schematic sectional illustration of a left ventricle of a mammalian heart showing anatomical structures and a native mitral valve; 
         FIG. 3  is a simplified section of a human heart and illustrating a medical device having attained transseptal access of the left atrium; 
         FIG. 4  is a simplified plan view of a system for transcatheter delivery of a prosthetic heart valve including a delivery device and a guide member assembly in accordance with principles of the present disclosure; 
         FIGS. 5A-5C  illustrate methods in accordance with principles of the present disclosure; 
         FIG. 6A  is a simplified side view of guide member assembly in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure, the assembly including a docking structure in a delivery arrangement; 
         FIG. 6B  is a simplified side view of the guide member assembly of  FIG. 6A , illustrating the docking structure in a capture arrangement; 
         FIGS. 7A-7C  illustrates methods of the present disclosure, including use of the guide member assembly of  FIG. 6A ; 
         FIG. 8  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure; 
         FIG. 9  illustrates methods of the present disclosure, including use of the guide member assembly of  FIG. 8 ; 
         FIGS. 10A and 10B  are simplified side views of another guide member assembly in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure; 
         FIG. 11  illustrates methods of the present disclosure, including use of the guide member assembly of  FIGS. 10A and 10B ; 
         FIG. 12  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure; 
         FIG. 13  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and in performing methods of the present disclosure; 
         FIG. 14  is a simplified perspective view of another guide member assembly in accordance with principles of the present disclosure and in performing methods of the present disclosure; 
         FIGS. 15A-15E  illustrates methods of the present disclosure, including use of the guide member assembly of  FIG. 14 ; 
         FIG. 16  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure; 
         FIGS. 17A-17B  illustrates methods of the present disclosure, including use of the guide member assembly of  FIG. 16 ; 
         FIG. 18  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and in performing methods of the present disclosure; 
         FIG. 19  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and in performing methods of the present disclosure; 
         FIG. 20  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure; 
         FIG. 21  is an enlarged side view of a portion of a docking structure of the guide member assembly of  FIG. 20 ; 
         FIGS. 22A-22D  illustrates methods of the present disclosure, including use of the guide member assembly of  FIG. 20 ; 
         FIG. 23  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and in performing methods of the present disclosure; 
         FIG. 24  is a simplified side view of another guide member assembly in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure; 
         FIG. 25  is a photograph of a portion of the guide member assembly of  FIG. 24 ; 
         FIG. 26  is a simplified side view of a distal portion of a delivery device in accordance with principles of the present disclosure and useful with the systems and methods of the present disclosure; 
         FIG. 27  is a simplified sectional view of a human heat and illustrating a distal end portion of a delivery device in accordance with principles of the present disclosure having attained transseptal access of the left atrium; and 
         FIGS. 28-31  illustrate a method in accordance with principles of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Specific embodiments of the present disclosure are now described with reference to the figures, wherein like reference numbers indicate identical or functionally similar elements. The terms “distal” and “proximal” are used in the following description with respect to a position or direction relative to the treating clinician. “Distal” or “distally” are a position distant from or in a direction away from the clinician. “Proximal” and “proximally” are a position near or in a direction toward the clinician. As used herein with reference to an implanted valve prosthesis, the terms “distal”, “outlet”, and “outflow” are understood to mean downstream to the direction of blood flow, and the terms “proximal”, “inlet”, or “inflow” are understood to mean upstream to the direction of blood flow. In addition, as used herein, the terms “outward” or “outwardly” refer to a position radially away from a longitudinal axis of a delivery device or a frame of the valve prosthesis and the terms “inward” or “inwardly” refer to a position radially toward a longitudinal axis of the delivery device or the frame of the valve prosthesis. As well the terms “backward” or “backwardly” refer to the relative transition from a downstream position to an upstream position and the terms “forward” or “forwardly” refer to the relative transition from an upstream position to a downstream position. 
     Embodiments of the present disclosure provide systems, methods, tools and devices for treating a native heart valve, such as in delivering a prosthetic heart valve. Although the description is in the context of treatment of heart valves such as the mitral valve, the systems and methods of the present disclosure also may be used in any other body passageways, organs, etc., where it is deemed useful. Further, while the systems and methods of the present disclosure can be sell-suited for transseptal approaches to the left atrium and mitral valve, features of the present disclosure can also be implemented with other surgical approaches such as retrograde aortic delivery, antegrade approaches, transapical, transatrial, etc., and combinations thereof. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the present disclosure. 
     By way of background,  FIG. 1  is a schematic sectional illustration of a mammalian heart  30  that depicts the four heart chambers (right atria RA, right ventricle RV, left atria LA, left ventricle LV) and native valve structures (tricuspid valve TV, mitral valve MV, pulmonary valve PV, aortic valve AV).  FIG. 2  is a schematic sectional illustration of a left atria LA and left ventricle LV of the heart  30  showing anatomical structures and a native mitral valve MV. Referring to  FIGS. 1 and 2  together, the heart  30  comprises the left atrium LA that receives oxygenated blood from the lungs via the pulmonary veins. The left atrium LA pumps the oxygenated blood through the mitral valve MV and into the left ventricle LV during ventricular diastole. The left ventricle LV contracts during systole and blood flows outwardly through the aortic valve AV, into the aorta and to the remainder of the body. 
     In a healthy heart, the leaflets LF of the mitral valve MV meet evenly at the free edges or “coapt” to close and prevent back flow of blood during contraction of the left ventricle LV ( FIG. 2 ). Referring to  FIG. 2 , the leaflets LF attach the surrounding heart structure via a dense fibrous ring of connective tissue called an annulus AN which is distinct from both the leaflet tissue LF as well as the adjoining muscular tissue of the heart wall. In general, the connective tissue at the annulus AN is more fibrous, tougher and stronger than leaflet tissue. The flexible leaflet tissue of the mitral leaflets LF are connected to papillary muscles PM, which extend upwardly from the walls W of the left ventricle LV and the interventricular septum IVS, via branching tendons called chordae tendinae CT. 
     One example of a treatment procedure to be performed on the heart  30  is generally reflected by  FIG. 3 . A transcatheter delivery device  40  is shown after having been introduced into the vasculature via a percutaneous entry point (e.g., the Seldinger technique), and having been tracked through the vasculature and into the left atrium LA. For example, the percutaneous entry point may be formed in a femoral vein. Thereafter, a guidewire or guide member (not shown) is advanced through the circulatory system, eventually arriving at the heart. The guidewire is directed into the right atrium RA (e.g., via the vena cava), traverses the right atrium RA, and is made to puncture or otherwise pass through a hole H in the atrial septal wall W (e.g., with the aid of a transseptal needle), thereby entering the left atrium LA. Once the guidewire is positioned, the delivery device  40  is tracked over the guide wire and delivered transseptally to the left atrium LA. From the arrangement of  FIG. 3 , the delivery device  40  is further manipulated and/or operated to perform a treatment, such as delivering and deploying a prosthetic heart valve (e.g., maintained within a capsule  42  of the delivery device  40  in the state of  FIG. 3 ) at the mitral valve MV. In this regard, from the arrangement of  FIG. 3 , the delivery device  40 , and in particular the capsule  42 , should be caused to turn or track approximately 90 degrees downward in order to face and align with the mitral valve MV. Some embodiments of the present disclosure provide devices, tools, assemblies and methods useful with the delivery device  40  in guiding the capsule  42  (or other portion of the delivery device  40 ) into alignment with the mitral valve MV. 
     As a point of reference, the systems, devices, tools and methods of the present disclosure can be employed with a wide variety of differently-configured delivery devices. In general terms, and with reference to  FIG. 4 , one non-limiting embodiment of the delivery device  40  can include a delivery sheath assembly  50 , a support shaft assembly  52  (referenced generally), and a handle assembly  54 . The delivery device  40  provides a loaded or delivery state in which a prosthetic valve (hidden) is loaded over the support shaft assembly  52  and is retained within the capsule  42  of the delivery sheath assembly  50 . The support shaft assembly  52  can include an inner shaft (hidden) connected to or terminating at a tip  56 . The prosthetic valve is maintained over the inner shaft by the capsule  42 . A guide member or guidewire lumen (hidden) can be provided through the tip  56  and other portions of (including an entirety of) the support shaft assembly  52 , and can be open to a guide member or guidewire port (e.g., at the handle assembly  54 ). The delivery sheath assembly  50  can be manipulated to withdraw the capsule  42  from over the prosthetic heart valve via operation of the handle assembly  54 . In some embodiments, the prosthetic heart valve may then self-expand and release from the delivery device  40 . In other embodiments, the prosthetic heart valve may have a mechanically-expandable or balloon-expandable construction. For example, the delivery device  40  may include an inflatable component (e.g., a balloon) that is operated to expand the prosthetic heart valve following retraction of the capsule  42 . Other delivery device constructions are also envisioned by the present disclosure, for example delivery device configurations that do not include the capsule  42 . 
     With the above in mind, some aspects of the present disclosure relate to a guide member assembly  60  useful with the delivery device  40  as part of a prosthetic heart valve (or other medical device) delivery procedure, and corresponding methods of use. The delivery device  40  and the guide member assembly  60  combine to define a system  62  for delivering the prosthetic heart valve (or performing other transcatheter-based treatment procedures). As described below, the guide member assemblies of the present disclosure can assume a wide variety of forms, and features of some guide member assembly formats can be combined with or incorporated into other guide member assembly embodiments. 
     In some embodiments, the guide member assembly  60  provides a distal region  64 , and includes an elongated member (or rail or guide member)  70  and a docking structure  72  (shown in block form). In some embodiments, the elongated member  70  may comprise a surgical guidewire of known or conventional construction useful in the catheter arts and appropriate for insertion into a patient. In some embodiments, the elongated member  70  exhibits sufficient flexibility for atraumatic guidance through a patient&#39;s vasculature to the heart in accordance with an intended procedure, and sufficient rigidity for tracking or guiding a transcatheter delivery device (such as the exemplary delivery device  40  of  FIG. 4 )) over the elongated member  70 . In some embodiments, portions or an entirety of the elongated member  70  can be configured to assume a pre-determined shape (e.g., longitudinal curvature). In some embodiments, the elongated member  70  is not configured to self-assume a pre-determined shape. The elongated member  70  can be formed of metal, plastic, fibers, strands, wire, etc. (e.g., the elongated member  70  can comprise a wire or a suture). 
     The docking structure  72  is carried by or assembled to the elongated member  70  and is generally configured to interface or dock with expected native anatomy, for example native anatomy associated (e.g., adjacent) with the mitral valve. By way of non-limiting example and with additional reference to  FIG. 5A , the docking structure  72  can be configured to interface or dock with one or more native valve leaflets LF (e.g., the docking structure shown in block form and with dashed lines at  72   a ), one or more chordae CT (e.g., the docking structure shown in block form and with dashed lines at  72   b ), one or more of the walls W (e.g., the docking structure shown in block form and with dashed lines at  72   c ) of the left ventricle LV, etc., as described in greater detail below. As a point of further reference, the view of  FIG. 5A  illustrates portions of some non-limiting methods of the present disclosure in which the distal region  64  of the guide member assembly  60  has attained initial crossing of the inter-atrial septum H to the left atrium LA, then crossing of the mitral valve MV. A catheter or similar device (not shown) can be used in directing the elongated member  70  to the arrangement of  FIG. 5A  in some embodiments. Regardless, once the docking structure  72  is engaged with native anatomy (e.g., one or more of the leaflets, chordae CT, wall(s) W of the left ventricle LV, etc.), the elongated member  70  provides a stable rail over which a larger diameter system or device can be tracked or guided over, and, in some embodiments, eliminating the need for active steering of the larger system. 
     For example, in the view of  FIG. 5B , the delivery device  40  carrying a collapsed prosthetic mitral valve (hidden within the capsule  42 ) has been directed to the left atrium LA via a transseptal approach as described above. The guide member assembly  60  can be utilized in initially directing the delivery device  40  to the arrangement of  FIG. 5B . In some embodiments, the guide member assembly  60  can be manipulated, steered or advanced into the left atrium LA or left ventricle LV. In some embodiments, the guide member assembly  60  can be directed into the left atrium LA or left ventricle LV via a conventional guidewire. In some embodiments, a conventional guidewire can be employed to locate the delivery device  40  in the left atrium LA (e.g., to the arrangement of  FIG. 5B ), and then the guidewire can be replaced with the guide member assembly  60  (e.g., the guidewire is removed). Regardless, before, after or simultaneous with locating the capsule  42  within the left atrium LA, the distal region  64  of the guide member assembly  60  is manipulated, steered and/or advanced as described above, directing the docking structure  72  through and beyond the mitral valve MV. The guide member assembly  60  is then manipulated to dock the docking structure  72  to native anatomy. From the state of  FIG. 5B , the delivery device  40  is then advanced over the elongated member  70 , bringing the capsule  42  into the mitral valve MV as in  FIG. 5C . Because the docking structure  72  is relatively fixed to the native anatomy, a push/pull tension can be applied to the elongated member  70  allowing the delivery device  40  to be more readily distally advanced over the elongated member  70 . Further, because the elongated member  70  remains generally aligned with the mitral valve MV via the docked docking structure  72 , the capsule  42  will be similarly directed into and aligned with the mitral valve MV. The delivery device  40  is then operated to deploy the prosthetic heart valve. 
     Various examples of docking structures  72  in accordance with principles of the present disclosure are provided below. In some embodiments, the docking structure  72  can be configured to transition (e.g., expand and collapse) between a delivery arrangement and a deployed or capture arrangement or state. In some embodiments, the docking structure  72  can be selectively detachable from the elongated member  70 . Portions or an entirety of the docking structures of the present disclosure can be made from stainless steel, a pseudo-elastic metal such as a nickel titanium alloy or Nitinol™, or a so-called super alloy, which may have a base metal of nickel, cobalt, chromium, or other metal. In yet other embodiments, any of the docking structures of the present disclosure can alternatively be provided as part of the delivery device  40 , e.g., tip or nosecone  56  ( FIG. 4 ), with the so-configured tip  56  being advanced via the elongated member  70  to engage native anatomy as described below. 
     With the above explanations in mind, portions of one embodiment of a guide member assembly  80  in accordance with principles of the present disclosure and useful as the guide member assembly  60  ( FIG. 4 ) provided with the systems  62  ( FIG. 4 ) of the present disclosure is shown in simplified form in  FIGS. 6A and 6B . The guide member assembly  80  provides a distal region  82 , and includes the elongated member  70  as described above and a docking structure  84 . The docking structure  84  is carried by or assembled to the elongated member  70  and is generally configured to interface or dock with expected anatomy. For example, with the construction of  FIGS. 6A and 6B , the docking structure  84  includes at least one anchor member or arm  86  configured to selectively interface with a native valve leaflet(s), such as native mitral valve leaflets. In some embodiments, the docking structure  84  is configured such that the anchor member(s)  86  is collapsible, for example being transitionable between a delivery arrangement ( FIG. 6A ) and a deployed or capture arrangement ( FIG. 6B ). In the delivery arrangement, the anchor member(s)  86  has a streamlined shape, with at least majority, optionally an entirety, of the anchor member(s)  86  being in close proximity to the elongated member  70 . In the deployed or capture arrangement, at least a portion of the anchor member(s)  86  projects radially from the elongated member  70  to define a capture region. Stated otherwise, each of the anchor members  86  has a maximum radial dimension R relative to a longitudinal axis A defined by the elongated member  70 ; the maximum radial dimension R in the capture arrangement ( FIG. 6B ) is greater than the maximal radial dimension R in the delivery arrangement ( FIG. 6A ). In some embodiments, the capture arrangement includes the anchor member(s)  86  assuming or reverting to a curved shape in extension from the elongated member  70  as generally reflected by  FIG. 6B . In other embodiments, the anchor member(s)  86  can have a more linear or planar shape in projection from the elongated member  70  in the capture arrangement. Regardless, in some embodiments, the capture arrangement can include the anchor member(s)  86  projecting from the elongated member  70  in a generally proximal direction. For example, the anchor member(s)  86  can, in the capture arrangement, be viewed as defining or providing a base  90  and a tip  92 . The base  90  is most proximate the elongated member  70 , and effectively represents a point of departure of the anchor member  86  from the elongated member  70 . The tip  92  is defined opposite the base  90 , and can correspond to the maximal radial dimension R. With these definitions in mind, proximal projection of the anchor member  86  from the elongated member  70  in the proximal direction can include the tip  92  being proximal the base  90  (and radially spaced from the elongated member  70 ). 
     The optional collapsible configuration of the anchor member(s)  86  can be provided in various fashions. In some non-limiting embodiments, the docking structure  84  can further include first and second rings  94 ,  96 . As identified in  FIG. 6A , a first end  98  of each of the anchor members  86  is attached to the first ring  94 , and an opposing second end  100  is attached to the second ring  96 . The first ring  94  is fixedly mounted to the elongated member  70 , whereas the second ring  96  is slidably mounted over the elongated member  70  proximal the first ring  94 . During use, transitioning of the docking structure  84  includes the second ring  96  sliding along the elongated member  70  in the distal direction toward the first ring  94 , with the anchor member(s)  86  deflecting (or being caused to deflect) to the capture arrangement, including the tip  92  being located at a radial spacing from the elongated member  70 . A reverse action can be performed in transitioning of the anchor member(s)  86  from the capture arrangement to the delivery arrangement. In some embodiments, the guide member assembly  80  can further include one or more components or mechanisms by which a user can effect movement of the first ring  94  (e.g., a push/pull wire). In other embodiments, the anchor member(s)  86  can be configured to self-assume the capture arrangement (e.g., formed of a shape memory metal or similar material), and the guide member assembly  80  can further include an outer sheath or similar component that is slidably arranged over one or more portions of the elongated member  70  and slidably arranged over one or more portions of the anchor member(s)  86  in the delivery arrangement. With this optional construction, once removed from the confines of the outer sheath, the anchor member(s)  86  self-revert to the capture arrangement. Other configurations can be employed with the guide member assembly  80  to provide for collapsing of the anchor member(s)  86  that may or may not include the slidable ring  96 . In other embodiments, the docking structure  84  is not collapsible. 
     The guide member assembly  80  can be used in connection with a number of surgical procedures, such as in connection with the transcatheter delivery of a prosthetic heart valve, for example a prosthetic mitral valve as described above. With reference to  FIG. 7A , before, after or simultaneous with locating the capsule  42  within the left atrium LA, the distal region  82  of the guide member assembly  80  is manipulated, steered, and/or advanced into the heart. The distal region  82  is then further manipulated to advance the docking structure  84  through and beyond the mitral valve MV. With embodiments in which the docking structure  84  provides for a delivery arrangement and a capture or deployed arrangement, the docking structure  84  can be in the delivery arrangement when being directed through the mitral valve MV, and then transitioned to the capture or deployed arrangement. The guide member assembly  80  is then manipulated to dock the docking structure  84  to one or more of the leaflets LF. For example, with the docking structure  84  in the capture arrangement, the elongated member  70  can be distally retracted, causing the anchor member(s)  86  to capture or engage with one or more of the leaflets LF, resulting in the arrangement of  FIG. 7A . The anchor member(s)  86  can include features that grab or pinch the leaflet(s) of the mitral valve MV. 
     The delivery device  40  is then advanced over the elongated member  70  of the docked guide member assembly  80 , bringing the capsule  42  (and the collapsed prosthetic valve within the capsule  42 ) into the mitral valve MV as in  FIG. 7B . The delivery device  40  is then operated to deploy the prosthetic heart valve  110  as shown in  FIG. 7C . For example, the capsule  42  can be retracted from over the prosthetic heart valve  110 , permitting the prosthetic heart valve  110  to self-expand or otherwise deploy from the delivery device  40 . Following deployment or implantation of the prosthetic heart valve  110 , at least a portion of the guidewire assembly  80  is removed from the patient. For example, in some embodiments, the docking structure  84  is released from the leaflet(s) LF by distally advancing the elongated member  70 , followed by transitioning of the docking structure  84  back to the delivery arrangement ( FIG. 7A ). The entire guide member assembly  80  can then be withdrawn from the patient. 
     Other surgical procedures can be facilitated using the guide member assembly  80 , and the methods of the present disclosure are not limited to delivering a prosthetic heart valve. Further, other methods of the present disclosure can include temporarily or permanently docking the docking structure  84  to other native anatomical features, and are not limited to native valve leaflets LF. For example, and with additional reference to  FIG. 5A , the docking structure  84  can be docked to chordae CT, cardiac wall(s) W, etc. 
     The docking structures of the present disclosure can assume a wide variety of other forms configured, for example, to promote docking with or within the chordae CT. For example, portions of another embodiment guide member assembly  120  are shown in simplified form in  FIG. 8 . The guide member assembly  120  includes the elongated member  70  as described above along with a docking structure  124 . With the embodiment of  FIG. 8 , the docking structure  124  includes an inflatable anchor member  126 , such as a balloon. An inflation medium can be supplied to an interior of the inflatable anchor member  126  via a lumen formed by the elongated member  70 , or by tubing (not shown) carried by the elongated member  70 . Regardless, the docking structure  124  is transitionable between the capture or deployed arrangement of  FIG. 8  in which the inflatable anchor member  126  has been inflated, and a delivery arrangement in which the inflation medium has been evacuated from the inflatable anchor member  126 , causing the inflatable anchor member  126  to collapse onto the elongated member  70 . As part of the methods described above, and with additional reference to  FIGS. 5A and 5B , the docking structure  124  (deflated or in the delivery arrangement) is advanced into the chordae CT ( FIG. 5A ). The inflatable anchor member  126  is then inflated (e.g., transitioned to the capture arrangement) so as to become caught up in or otherwise captured at the chordae CT. This is further reflected by  FIG. 9 . With continued reference to  FIGS. 5A, 5B and 8 , the delivery device  40  can then be advanced over the elongated member  70  to a desired location, for example locating a collapsed prosthetic heart valve (within the capsule  42 ) at the native mitral valve MV. Following deployment or implantation of the prosthetic heart valve, at least a portion of the guide member assembly  120  is removed from the patient. For example, in some embodiments, the docking structure  124  is released from the chordae CT by deflating the inflatable anchor member  126 , by causing the inflatable anchor member  126  to burst, etc. The entire guide member assembly  120  can then be withdrawn from the patient. 
     In other embodiments, the docking structures and corresponding methods of use are configured for docking in a cardiac wall W, such as one or more walls W of the left ventricle LV as part of a transcatheter prosthetic mitral valve delivery procedure. The docking structures can include one or more anchor members such as screws, hooks, barbs, pincers, etc., appropriate for engaging or embedding into cardiac wall tissue. The docking structure and corresponding method of use can include docking in the apex of the left ventricle LV or side walls W of the heart depending upon alignment. The docking structure and corresponding methods of use can include a portion of the docking structure being disconnected from the elongated member  70  and remaining in situ (e.g., in the left ventricle wall W), or can be removed following the procedure (e.g., implantation of the prosthetic heart valve). 
     For example, another embodiment guide member assembly  130  in accordance with principles of the present disclosure is shown in  FIGS. 10A and 10B , and includes the elongated member  70  as described above along with a docking structure  134  and an outer sheath or jacket  136 . The docking structure  134  is transitionable between a delivery arrangement (labeled as  134 ′ in  FIG. 10A ) and a capture or deployed arrangement as shown in  FIG. 10B , and includes one or more anchor members  138 , such as barbs, clips or other anchor members, extending from a base  140  and terminating at a tip  142  configured to pierce tissue. In some embodiments, the anchor members  138  are configured (e.g., shape memory material) or biased to the capture or deployed arrangement. The base  140  is connected to the elongated member  70  (permanently attached, releasably attached, etc.). The outer sheath  136  is slidably disposed over the elongated member  70  and forms a capsule  144  terminating at a distal end  146 . The capsule  144  is configured (e.g., size, shape, hoop strength, etc.) to force and restrain the docking structure  134 , and in particular the anchor members  138 , to the delivery arrangement when disposed over the docking structure  134 . One or both of the elongated member  70  and/or the outer sheath  136  can be provided with steering features. 
     Some methods of the present disclosure making use of the guide member assembly  130  can include directing the guide member assembly  130 , in the delivery arrangement, to the left ventricle LV ( FIG. 5A ) commensurate with the above explanations. The distal end  146  of the outer sheath  136  is located against the native anatomy structure of interest (e.g., a wall of the left ventricle LV). The docking structure  134  is then advanced relative to the capsule  144 , with the tip  142  of each of the anchor members  138  moving distally beyond the distal end  146  and piercing into tissue. With further distal movement of the docking structure  134  and/or proximal retraction of the capsule  144 , the docking structure  134  self-transitions to the capture or deployed arrangement, with the anchor members  138  embedding into the native anatomy. The outer sheath  136  can then be withdrawn, as shown for example in  FIG. 11 , with the docking structure  134  remaining docked to or embedded within tissue of the wall W of the left ventricle LV. A delivery device (such as the delivery device  40  ( FIG. 5B )) can then be tracked or advanced over the elongated member  70  of the now-docked guide member assembly  130 , followed by deployment of the prosthetic heart valve as described above. Once the procedure is complete, the outer sheath  136  ( FIG. 10A ) can be distally advanced over the elongated member  70 , bringing the capsule  144  into close proximity with the docking structure  134 . With further distal advancement of the capsule  144  and/or proximal retraction of the docking structure  134 , the docking structure  134  releases from engagement with the native anatomy and returns to the delivery arrangement within the capsule  144 . The guide member assembly  130  can then be withdrawn from the patient. In some embodiments, the outer sheath  136  is not withdrawn prior to placement of the delivery device (e.g., the delivery device  40  ( FIG. 5B )) such that the delivery device is advanced over the outer sheath  136  of the guide member assembly  130 . 
     Another embodiment guide member assembly  150  in accordance with principles of the present disclosure is shown in  FIG. 12 , and includes the elongated member  70  as described above along with a docking structure  154 . The docking structure  154  is or includes two or more clips or anchor members  156  each carried within a lumen or lumens (not shown) of the elongated member  70 . The anchor members  156  are biased to assume the capture or deployed arrangement depicted in  FIG. 12 , and can be retracted within the corresponding lumen of the elongated member  70 , bending to a straightened shape to provide a delivery arrangement. In some embodiments, the docking structure  154 , and optionally the elongated member  70 , incorporate clip retraction and deployment features and technology embodied by a miniature transcatheter pacing system available under the trade designation MICRA™ from Medtronic, Inc. Some methods of the present disclosure making use of the guide member assembly  150  can be highly akin to the methods above with respect to the guide member assembly  130  ( FIG. 10 ) in which the docking structure  154  is transitioned to the capture or deployed arrangement, engaging tissue (e.g., cardiac wall ( FIG. 5A )) and docking the elongated member  70  relative to the native anatomy. 
     Another embodiment guide member assembly  160  in accordance with principles of the present disclosure is shown in  FIG. 13 , and includes the elongated member  70  as described above along with a docking structure  164 . The docking structure  164  is attached to or carried by the elongated member  70  and provides the capture arrangement as shown in which the docking structure  164  spans the left ventricle LV and docks or engages opposing wall sections W 1 , W 2  of the left ventricle LV. For example, the docking structure  134  can included two or more anchor members, such as anchor members  166   a ,  166   b , that project generally radially in differing directions from the elongated member  70 ; when brought into anchoring contact with wall sections W 1 , W 2 , the anchor members  166   a ,  166   b  serve to generally center the elongated member  70  relative to the left ventricle LV (and thus generally center the elongated member  70  relative to the mitral valve MV). The anchor members  166   a ,  166   b  can self-deploy (e.g., shape memory metal) to the capture or deployed arrangement from a delivery arrangement in some embodiments. Regardless, the guide member assembly  160  can be used with methods of the present disclosure commensurate with the descriptions above. 
     Portions of another embodiment guide member assembly  170  in accordance with principles of the present disclosure are shown in  FIG. 14 , and includes one or more of the elongated members  70  as described above along with one or more docking structures  174  and an outer sheath or jacket  176 . In one embodiment, and as shown in  FIG. 14 , the guide member assembly  170  includes three elongated members  70   a ,  70   b ,  70   c , each terminating at or carrying a docking structure  174   a ,  174   b ,  174   c  that includes an anchor member  180  (e.g., a screw, barb, etc.). The elongated member  70   a ,  70   b ,  70   c  are slidably disposed along or within corresponding lumens of the outer sheath  176 . The guide member assembly  170  can further include one or more steering wires (not shown) connected to the outer sheath  176  and operable to manipulate or steer the outer sheath  176  as described in greater detail below. The outer sheath  176  can be a polymer or co-polymer material, such as medical-grade thermoplastic polyurethane elastomers. The elongated members  70   a ,  70   b ,  70   c  can be made of a rigid material such as stainless steel, nitinol, PTFE, etc. The anchor members  180  (e.g., screws) can be formed as a stainless steel or nitinol coil, etc. 
     Some methods of the present disclosure making use of the guide member assembly  170  can a delivery arrangement wherein the docking structures  174   a ,  174   b ,  174   c  are positioned within the outer sheath  176 . The so-loaded outer sheath  176  is then steered or advanced over a guidewire and into the left ventricle LV as in  FIG. 15A . The outer sheath  176  is then manipulated (e.g., retracted, steered, etc.) to expose the anchor body  180  of the first docking structure  174   a . The corresponding elongated member  70   a  is then manipulated to directing the docking structure  174   a  toward a native tissue wall section W 1  of the left ventricle LV as in  FIG. 15B . The anchor body  180  can be a sharpened coil or screw that readily digs into the anatomy as shown in  FIG. 15C . The first elongated member  70   a  is rotated, applying a torque onto the first docking structure  174   a  to achieve robust engagement with the wall section W 1 . A tugging force can then be applied onto the first elongated member  70   a  to confirm that the anchor body  180  of the first docking structure  174   a  is embedded into the wall section W 1 . This same process is repeated for placing the second docking structure  174   b  into a separate wall section W 2  ( FIG. 15D ), followed by placement of the third docking structure  174   c  into a separate wall section W 3  ( FIG. 15E ). The delivery device (not shown) can then be advanced over the outer sheath  176  commensurate with the descriptions above. The guide member assembly  170  is configured such that by individually placing the three docking structures  174   a ,  174   b ,  174   c  independent of one another, the three elongated members  70   a ,  70   b ,  70   c  can be individually manipulated to effectively create steering at the tip of the outer sheath  176 . Following deployment of the prosthetic heart valve (not shown) or other procedure, the elongated members  70   a ,  70   b ,  70   c  can be rotated or twisted to “unscrew” the corresponding docking structure  174   a ,  174   b ,  174   c  from the tissue wall. Once released, the guide member assembly  170  can be withdrawn from the patient. 
     Another embodiment guide member assembly  190  in accordance with principles of the present disclosure is shown in  FIG. 16 , and includes the elongated member  70  as described above along with a docking structure  194  and an outer sheath or jacket  196 . The docking structure  194  can include a base  198  and two (or more) anchor members (e.g., barbs)  200 . The base  198  is configured for selective attachment to a distal end of the elongated member  70 . For example, the base  198  and the elongated member  70  can have complementary threaded surfaces; other temporary attachment constructions are also acceptable. The anchor members  200  project from the base  198  and can each terminate at a sharp tip appropriate for piercing tissue. The outer sheath  196  can be a thin wall sheath and is slidably disposed over the elongated member  70 . In the delivery arrangement of  FIG. 16 , the outer sheath  196  is located over the docking structure  194 , collapsing the anchor members  200  toward one another. The docking structure  194  is configured to self-transition to a capture or deployed arrangement when released from the outer sheath  196  as described below (e.g., as a distal end  202  of the outer sheath  196  is proximally retracted relative to the anchor members  200 ). For example, one or more portions of the docking structure  194  can be formed from a surgically safe metal or metal alloy (e.g., stainless steel, nitinol, etc.) shape set to self-revert to the capture or deployed arrangement. 
     Some methods of the present disclosure making use of the guide member assembly  190  can include directing the guide member assembly  190 , in the delivery arrangement, to the left ventricle LV ( FIG. 5A ) commensurate with the above explanations. The distal end  202  of the outer sheath  196  is located against the native anatomy structure of interest (e.g., a wall of the left ventricle LV). The outer sheath  196  is then retracted relative to the docking structure  194  (and/or the elongated member  70 , and thus the docking structure  194 , is distally advanced relative to the outer sheath  196 ); the anchor members  200  self-transition toward the capture or deployed arrangement, embedding into tissue of the heart wall. For example,  FIG. 17A  illustrates the docking structure  194  in the capture or deployed arrangement and engaged with the wall W 2  of the left ventricle LV. Alternatively, and as shown with dashed lines, the docking structure  194  can be docked to an apex A of the left ventricle LV. Regardless, methods of the present disclosure can include tracking a delivery device (such as the delivery device  40  ( FIG. 5A )) over the elongated member  70  of the now-docked or anchored guide member assembly  190 , followed by deployment of the prosthetic heart valve  110  as shown in  FIG. 17B . The elongated member  70  can then be disconnected from the docking structure  194  (e.g., the elongated member  70  can be rotated to unscrew or unthread from the docking structure  194 ). Once disconnected, the elongated member  70  can be removed from the patient, while the docking structure  194  remains in situ. 
     Any of the docking structures of the present disclosure can be utilized with methods of the present disclosure in which the docking structure is docked to the apex A of the left ventricle LV. For example, another embodiment guide member assembly  210  is shown in  FIG. 18 , and includes the elongated member  70  and a docking structure  214  which may comprise a helix formed into or at the tip of the elongated member  70  (e.g. 0.032 inch diameter elongated member). The guide member assembly  210  has been delivered (e.g., via a small diameter delivery system) through the inter-arterial septum, and then through the mitral valve MV. The docking structure  214  has then been anchored to native anatomy of the walls W of the left ventricle LV at or near the apex A. The so-docked guide member assembly  210  provides a stable rail that a large diameter delivery system (e.g., the delivery device  40  ( FIG. 5B )) can be advanced, tracked, or guided over as described above. 
     As mentioned above, with any of the guide member assemblies of the present disclosure, the elongated member  70  can be configured to self-assume or be biased toward (e.g., formed of a shape memory material) a predetermined shape or curvature that is beneficial for particular procedures. For example, another embodiment guide member assembly  220  in accordance with principles of the present disclosure is shown in  FIG. 19 . The guide member assembly  220  includes an elongated member  70 ′ connected to a docking structure  224 , and a delivery tube  226 . The docking structure  224  can assume any of the formats or constructions described through the present disclosure, and is generally configured to engage or anchor to native tissue. The elongated member  70 ′ can be akin to conventional guidewire constructions known in the art, but is formed to self-assume the curved shape as shown. The curvature and other dimensions or geometries of the pre-determined shape correspond with transseptal advancement of the elongated member  70 ′ to the left ventricle LV and docking of the docking structure  224  to native anatomy. The predetermined shape naturally locates the elongated member  70 ′ through the mitral valve MV and within the septum; with this arrangement, as the elongated member  70 ′ is delivered and a delivery device (not shown) tracked over the elongated member  70 ′, the elongated member  70 ′ will not exert significant forces on tissue of the septum (a problem known as “cheese grating” with conventional flossing techniques). The delivery tube  226  can be relatively more rigid than the elongated member  70 ′, and assists in temporarily straightening the pre-formed curvature in the elongated member  70 ′ for initial delivery to the heart. 
     Returning to  FIG. 4 , in some optional embodiments, both the elongated member  70  and the docking structure  72  include electrically conductive materials (e.g., the elongated member  70  can include an electrically conductive metal wire surrounded by an electrical insulator, and the docking structure includes a metal hook, coil, barb, clip, tine, etc., that is electrically connected to the metal wire). With these and similar constructions, the guide member assembly  60  can further include (or be connected to) a source of energy (e.g., a pacing device), and can be configured to perform various electrical energy-type procedures on a patient as part of, for example, transseptal delivery of a prosthetic mitral valve. With these and related embodiments, the guide member assembly  60  can serve as a pacing lead, for example, in addition to providing the delivery device tracking features described above. With these and related embodiments, once the docking structure  72  is in contact with native tissue of interest, the guide member assembly  60  can be operated as a temporary cardiac pacing wire, and allows for rapid pacing of the patient&#39;s heart during deployment of the prosthetic heart valve. The pacing or other electrical energy related procedures could be performed on the left ventricle LV ( FIG. 1 ) or other areas of the patient&#39;s heart (e.g., the left atrium LA ( FIG. 1 )). As a point of reference, conventional pacing leads are too flexible or do not otherwise have sufficient rigidity for tracking of a transcatheter prosthetic heart valve delivery device loaded with a compressed prosthetic heart valve. In contrast, the guide member assemblies of the present disclosure (such as with some embodiments of the elongated member  70 ) are mechanically robust, capable of traversing a tortuous pathway and capable of directing a tracked transcatheter prosthetic heart valve delivery device along a curved pathway. 
     As mentioned above, in some embodiments, the docking structure  72  can be or include an inflatable anchor member (e.g., the docking structure  124  of  FIG. 8 ). With these and related embodiments, the inflatable docking structure can be configured (e.g., inflated size and shape) to engage or anchor against various native structures of the patient&#39;s heart. For example, another embodiment guide member assembly  230  in accordance with principles of the present disclosure is shown in  FIG. 20 . The guide member assembly  230  includes the elongated member  70  as described above, along with a docking structure  234 . The docking structure  234  includes an inflatable anchor member  236  (e.g., a balloon) and optional grip bodies  238 . The inflatable anchor member  236  can be directly attached to the elongated member  70  (with the elongated member  70  having a lumen for delivering an inflation medium to an interior of the inflatable member  236 ). Alternatively, the inflatable anchor member  236  can be provided as part of a balloon catheter that is slidably disposed over the elongated member  70  and forms requisite inflation lumen(s). Regardless, the inflatable anchor member  236  is transitionable between a delivery arrangement (not shown) and the capture or deployed arrangement of  FIG. 20  (in which the inflatable anchor member  236  has been inflated); in the capture or deployed arrangement, the inflatable anchor member  236  is sized and shaped to lodge or anchor in the left ventricle LV ( FIG. 1 ) as described in greater detail below. 
     The grip bodies  238 , where provided, are carried on an exterior of the inflatable anchor member  236  and are configured to provide a more robust engagement or purchase with native tissue. The grip bodies  238  can assume various forms, and in some embodiment have a directional bias for reasons made clear below. In some non-limiting embodiments reflected by  FIG. 21 , the grip bodies  238  can be akin to scales or ribs, projecting from the inflatable anchor member  236  to a tip (e.g. sharp tip)  240 . A shape or profile of one or more of the grip bodies  238  can be such that tip  240  is biased away from a distal end  242  of the inflatable member  236 . With this construction, the grip bodies  238  will more overtly resist a pulling force in the proximal direction, and will more easily “slip” in response to a force in the distal direction. This “biased” attribute can be provided with a number of other configurations. For example, the grip bodies  238  can be a number of extremely stiff and flat arms that naturally project perpendicular to the surface of the inflatable anchor member  236  when the inflatable anchor member  236  is inflated/expanded; when the inflatable anchor member  236  is deflated, the stiff and flat arms can readily “flip” in any direction. With this optional construction, the grip bodies  238  promote robust engagement of the docking structure  234  with native anatomy with expansion of the inflatable anchor member  236 , and allow the docking structure  234  to easily release from the native anatomy with deflation of the inflatable anchor member  236 . The grip bodies  238  can be relatively large and sturdy as shown. In other embodiment, the grip bodies  238  can have a very small scale (e.g., micro-sized bodies) and are disposed over a larger surface area of the inflatable anchor member  236 . 
     Some methods of the present disclosure making use of the guide member assembly  230  can include transseptally inserting a elongated member, such as the elongated member  70 , into the left ventricle LV as in  FIG. 22A . The docking structure  234  (with the inflatable anchor member  236  deflated) is then advanced to the bottom of the left ventricle LV as in  FIG. 22B . The docking structure  234  can be carried by the elongated member  70 , can be slidably disposed over the elongated member  70 , the previously-inserted elongated member can be replaced by the elongated member  70  otherwise carrying the docking structure  234 . Regardless, and with additional reference to  FIG. 22C , the inflatable anchor member  236  is pressed deep into the left ventricle LV (e.g., at the apex A) and constant pressure is held while the inflatable anchor member  236  is inflated. As the inflatable anchor member  236  inflates, it presses against the apex A and begins to push upwards. As the inflatable anchor member  236  comes into contact with the complex wall structure W of the left ventricle LV, the grip bodies  238  intimately catch into the wall structure W. The docking structure  234  thus becomes lodged in the left ventricle LV, effectively anchoring the elongated member  70 . The so-docked guide member assembly  230  provides a stable rail that a larger diameter delivery system (e.g., the delivery device  40  ( FIG. 5B )) can be tracked over as described above. Because the inflatable anchor member  236  is in place on the elongated member  70 , in some embodiments the tip of the delivery device is a rapid exchange (Rx) style tip in order to allow for the larger diameter of the docking structure  234  without forcing the delivery system to have an increased diameter. As a point of reference, the expanded inflatable anchor member  236  is shown in  FIG. 22C  as occupying a fairly large volume of the left ventricle LV for ease of understanding. In other embodiments, the inflatable anchor member  236  is sized and shaped to occupy less than a majority (e.g., no more than 25%, alternatively approximately 20%) of an available volume of the left ventricle LV as generally reflected by the inflatable anchor member  236 ′ shown in  FIG. 22D . It will be understood that the expanded inflatable anchor member  236 ′ will reduce the open volume of the left ventricle LV and may impede some level of contraction above the inflatable anchor member  236 ′, but not prevent it. In some embodiments, the inflatable anchor member  236 ′ is made as small as possible while still achieving a desired level of grip to the native anatomy. 
     While some methods described above entail use of a guide member assembly of the present disclosure in performing a transseptal access to the mitral valve and anchoring or docking at or within the left ventricle to facilitate delivery of a prosthetic mitral valve, other surgical approaches are also envisioned by the present disclosure. For example,  FIG. 23  illustrates another embodiment guide member assembly  250  in performing a retrograde aortic access or delivery procedure. The guide member assembly  250  includes the elongated member  70  as described above, along with a docking structure  254 . The docking structure  254  can assume any of the formats described in the present disclosure, and in some embodiments is or includes an inflatable anchor member (e.g., a balloon)  256 . To attain the arrangement of  FIG. 23 , the elongated member  70  is advanced to the left ventricle LV via a retrograde aortic approach and then toward the mitral valve MV. In this regard, the inflatable anchor member  256  can assist in navigating through the chordae CT in the left ventricle LV, for example by slightly inflating the inflatable anchor member  256 , may better ensure that the elongated member  70  has a clear path to the center of the mitral valve MV. Once located in the left atrium LA, the docking structure  254  can be operated or manipulated to dock to native anatomy as described above. Once anchored, the elongated member  70  is stabilized for tracking of a prosthetic heart valve delivery device commensurate with the descriptions above. 
     In some embodiments of the present disclosure, any of the guide member assemblies disclosed herein can incorporate a steerable elongated member or rail. For example, another guide member assembly  270  in accordance with principles of the present disclosure is shown in  FIG. 24  and includes a steerable rail or elongated member  272 , a handle  274 , and an optional docking structure  276 . The steerable elongated member  272  can assume various forms known in the art appropriate for providing steering capabilities. For example, two or more rail or rod segments can by pivotably (and/or rotatably) coupled to one another, and pull wires (or other actuators) provided; an operator can manipulate or steer the rod segment relative to one another via the handle  274 . Other steering features known in the catheter art, for example, can be incorporated into the steerable elongated member  272  (e.g., hydraulic-based steering mechanisms). Regardless, during a surgical procedure, such as the transseptal prosthetic mitral valve delivery procedures described above, the prosthetic mitral valve delivery device (e.g., the delivery device  40  of  FIG. 4 ) rides or tracks over the steerable elongated member  272 . As the capsule  52  ( FIG. 4 ) and thus the collapsed prosthetic mitral valve constrained therein pass from the right atrium into the left atrium, and then into the left ventricle, the pull wires (or other actuators) can be operated or manipulated to alter or articulate the shape of the steerable elongated member  272 . As the capsule/collapsed valve enters the native mitral valve annulus, additional steering of the distal end of the steerable elongated member  272  located deep in the left ventricle could help to center the prosthetic heart valve in the native valve annulus. With related methods, the steerable elongated member  272  can be used by pushing against the walls of the heart chamber(s) to deflect the prosthetic heart valve delivery device into a desired position. 
     Where provided, the optional docking structure  276  can assume various forms. In some embodiments, the docking structure  276  is configured to facilitate desired deflection of the steerable elongated member  272  against native anatomy. In some embodiments, the docking structure  276  can be or include a basket-type body  278  as shown in  FIG. 25 . The basket  278  may more effectively push the steerable elongated member  272  and therefor aid in orientating the prosthetic heart valve delivery device toward the center of the native mitral valve annulus. 
     As mentioned above, in some embodiments, any of the docking structures of the present disclosure can alternatively be provided as part of the delivery device  40 , e.g., a guide member assembly  360  can be provided as part of the delivery device  40  wherein the guide member assembly  360  includes a docking structure  372 , which can also be configured as a tip or nosecone for delivery device  40 , and an elongated member  370  ( FIG. 26 ). In some embodiments, the delivery device  40  can include a delivery sheath assembly  50 , a support shaft assembly  52 , a handle assembly  54  ( FIG. 4 ), and a guide member assembly  360  wherein the delivery device  40  provides a loaded or delivery state in which a prosthetic valve is loaded over the support shaft assembly  52  and is retained within the capsule  42  of the delivery sheath assembly  50 . The guide member assembly  360  includes a docking structure  372  carried by or connected to the distal end of the elongated member  370 . The docking structure  372  is generally configured to interface or dock with expected anatomy. A guidewire lumen  380  can be provided through the docking structure  372  and through the elongated member  370  and can be open to a guidewire port (e.g., at the handle assembly  54 ). The support shaft assembly  52  can include an inner shaft  354  having a guide member lumen  390 . The docking structure  372  can be advanced from the distal end of the inner shaft  354  via manipulation or advancement of the elongated member  370  through the lumen  390  of the inner shaft  354 . The docking structure  372  is configured to engage native anatomy as described above. Once the docking structure  372  is relatively fixed to the native anatomy, a push/pull tension can be applied to the elongated member  370  allowing the support shaft assembly  52  and the delivery sheath assembly  50  of the delivery device  40  to be more readily distally advanced over the elongated member  370 . Further, because the elongated member  370  can be generally aligned with the mitral valve MV via the docked docking structure  372 , the capsule  42  will be similarly directed into and aligned with the mitral valve MV. The delivery device  40  is then operated to deploy the prosthetic heart valve. 
     In some embodiments, the docking structure  372  can be configured to transition (e.g., expand and collapse) between a delivery arrangement wherein the docking structure  372  is configured for use as a tip or nosecone for delivery device  40  and a deployed or capture arrangement wherein the docking structure  372  is used to engage native anatomy as described above. In some embodiments, the docking structure  372  can be selectively detachable from the elongated member  370  as described above. In some embodiments, the docking structure  372  can include one or more anchor members as described above. 
     One example of a treatment procedure to be performed on the heart  30  is generally reflected by  FIG. 27 . A transcatheter delivery device  40  is shown after having been introduced into the vasculature via a percutaneous entry point (e.g., the Seldinger technique), and having been tracked through the vasculature and into the left atrium LA. For example, the percutaneous entry point may be formed in a femoral vein. Thereafter, a guidewire (not shown) assembly is advanced through the circulatory system, eventually arriving at the heart. The guidewire assembly is directed into the right atrium RA (e.g., via the vena cava), traverses the right atrium RA, and is made to puncture or otherwise pass through a hole H in the atrial septal wall W (e.g., with the aid of a transseptal needle), thereby entering the left atrium LA. Once the guidewire assembly is positioned, the delivery device  40  is tracked over the guidewire assembly and delivered transseptally to the left atrium LA. From the arrangement of  FIG. 27 , the elongated member  370  is manipulated, steered, and/or advanced as described above, directing the docking structure  372  through and beyond the mitral valve MV ( FIG. 28 ). The guide member assembly  360  is then manipulated to dock the docking structure  372  to native anatomy. In some embodiments, the docking structure  372  can include one or more inflatable anchor members and/or one or more grip bodies as described above. In some embodiments, the docking structure  372  can be pressed deep into the left ventricle LV (e.g., at the apex A) and anchored or lodged into position as described earlier. The so-docked guide member assembly  360  provides a stable rail that the support shaft assembly  52  and the delivery sheath assembly  50  of the delivery device  40  can then be tracked over, bringing the capsule  42  into the mitral valve MV as in  FIG. 29 . Because the docking structure  372  is relatively fixed to the native anatomy, a push/pull tension can be applied to the elongated member  370  allowing the delivery device  40  to be more readily distally advanced over the elongated member  370 . Further, because the elongated member  370  can be generally aligned with the mitral valve MV via the docked docking structure  372 , the capsule  42  will be similarly directed into and aligned with the mitral valve MV. The delivery device  40  is then operated to retract capsule  42  to thereby deploy the prosthetic heart valve  400  at the mitral valve MV ( FIG. 30 ). Following deployment of the prosthetic valve  400 , the docking structure  372  is either released from the elongated member  370  or, as shown in  FIG. 31 , the elongated member  370  is retracted or advanced proximally within the inner shaft  354  to relocate the docking structure  372  at the distal end of the inner shaft  354 . In addition, the capsule  42  is advanced back over the inner shaft  354  thereby reconfiguring the delivery device  40  from a deployed configuration or arrangement back into a delivery configuration or arrangement. Once the delivery device  40  has been reconfigured into a delivery configuration, the delivery device  40  is then removed from the patient. 
     The assemblies, systems and methods of the present disclosure provide a marked improvement over previous designs and techniques, for example in transcatheter delivery of a prosthetic mitral valve. By docking an elongated member or rail to native anatomy and utilizing the so-docked guide member assembly for advancing, tracking, or guiding the prosthetic heart valve delivery device to the target native mitral valve (e.g., a transseptal approach to the mitral valve from the left atrium), the anatomical complexities presented by transcatheter mitral valve delivery are addressed. 
     Although the present disclosure has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present disclosure.