Patent Description:
Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery.

Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve must first be collapsed or crimped to reduce its circumferential size.

When a collapsed prosthetic valve has reached the desired implant site in the patient (e.g., at or near the annulus of the patient's heart valve that is to be replaced by the prosthetic valve), the prosthetic valve can be deployed or released from the delivery apparatus and re-expanded to full operating size. For balloon-expandable valves, this generally involves releasing the entire valve, assuring its proper location, and then expanding a balloon positioned within the valve stent. For self-expanding valves, on the other hand, the stent automatically expands as the sheath covering the valve is withdrawn.

When a prosthetic heart valve is implanted into a native heart valve, it may be desirable for the commissures of the prosthetic heart valve (e.g. the areas at which a side of one prosthetic heart valve leaflet meet with a side of an adjacent prosthetic heart valve leaflet) to rotationally align with the native commissures of the native heart valve. Such alignment may help reduce the risk of coronary obstruction, and it may be generally desirable for the prosthetic valve to mimic the native valve anatomy as closely as possible. When implanting prosthetic heart valves surgically (i.e. through an open heart, open chest procedure), there is typically good visualization of the operative field, which makes alignment of the prosthetic commissures with the native commissures relatively easy. However, in transcatheter procedures, the entire surgical field is not capable of visualization by the naked eye of the surgeon. For example, deployment of the prosthetic heart valve in a transcatheter procedure is frequently performed under fluoroscopic imaging. Also, the prosthetic heart valve is typically positioned at one end of a delivery device whereas the surgeon is manipulating the opposite end of the delivery device. This can make it significantly more difficult to align the commissures of the prosthetic heart valve with the native valve commissures during a transcatheter heart valve replacement procedure compared to a surgical heart valve replacement procedure. Thus, it would be desirable for systems and methods to help assist with aligning commissures of a prosthetic heart valve with native heart valve commissures, particularly for transcatheter implantation systems.

<CIT> is directed to mitral valve replacement systems and methods, the system including an anchor assembly configured with feet or projections sized and shaped to engage an anatomical gutter located in the left ventricle proximate the mitral valve annulus which anchor assembly acts as support for subsequent implantation of a replacement valve assembly.

A delivery device helping in assisting with aligning commissures in accordance with the invention is set out in claim <NUM>.

According to one aspect of the disclosure, a delivery device for a collapsible prosthetic heart valve includes an inner shaft, an outer shaft, and a distal sheath. The distal sheath may be disposed distal to the outer shaft and about a portion of the inner shaft to form a compartment with the inner shaft. The compartment may be sized to receive the prosthetic heart valve. The inner shaft and the distal sheath may be movable relative to one another. A spine may extend along the outer shaft, the spine biasing the outer shaft so that the outer shaft tends to bend in a pre-determined direction.

According to another aspect of the disclosure, a method of implanting a prosthetic heart valve into a native aortic valve of a patient includes loading the prosthetic heart valve into a distal sheath of a delivery device in a collapsed condition, the prosthetic heart valve having three prosthetic commissures. The distal sheath of the delivery device may be advanced through an aortic arch of the patient so that an outer shaft of the delivery device includes a bend having an outer radius and an inner radius, one of the three prosthetic commissure confronting the outer radius of the bend during the advancing. The distal sheath may be continued to be advanced until the distal sheath is adjacent the native aortic valve and the distal sheath is positioned adjacent a native commissure between a right coronary cusp and non-coronary cusp of the patient. The distal sheath may be retraced and the prosthetic heart valve may expand so that the one of the three prosthetic commissure is positioned in rotational alignment with the native commissure.

According to a further aspect of the disclosure, a delivery device for a collapsible prosthetic heart valve includes an inner shaft, an outer shaft, and a distal sheath. The distal sheath may be disposed distal to the outer shaft and about a portion of the inner shaft to form a compartment with the inner shaft, the compartment being sized to receive the prosthetic heart valve. The inner shaft and the distal sheath may be movable relative to one another, the outer shaft and the distal sheath sharing a central longitudinal axis. The outer shaft may be joined to the distal sheath via a joint so that the distal sheath is capable of rotation about the central longitudinal axis while the outer shaft remains static relative to the central longitudinal axis.

As used herein in connection with prosthetic heart valves, the term "inflow end" refers to the end of the heart valve through which blood first flows when implanted in an intended position and orientation, while the term "outflow end" refers to the opposite end, through which blood last flows when the prosthetic heart valve is implanted in the intended position and orientation. When used in connection with devices for delivering a prosthetic heart valve into a patient, the terms "proximal" and "distal" are to be taken as relative to the user of the delivery devices. In other words, in this context, "proximal" is to be understood as relatively close to the user of the delivery device, and "distal" is to be understood as relatively farther away from the user of the delivery device.

<FIG> shows a collapsible prosthetic heart valve <NUM>. The prosthetic heart valve <NUM> is designed to replace the function of a native aortic valve of a patient, although it should be understood that the concepts described herein may be applicable to the replacement of any native heart valve, including the mitral, tricuspid, or pulmonary heart valves. As discussed in detail below, the prosthetic heart valve has an expanded condition, shown in <FIG>, and a collapsed condition.

Prosthetic heart valve <NUM> includes a collapsible and expandable stent <NUM> which may be formed from any biocompatible material, such as metals, metal alloys, synthetic polymers or biopolymers capable of functioning as a stent. Stent <NUM> extends from an inflow or annulus end <NUM> to an outflow or aortic end <NUM>, and includes an annulus section <NUM> adjacent the inflow end and an aortic section <NUM> adjacent the outflow end. The annulus section <NUM> has a relatively small cross-section in the expanded condition, while the aortic section <NUM> has a relatively large cross-section in the expanded condition. Preferably, annulus section <NUM> is in the form of a cylinder having a substantially constant diameter along its length. A transition section <NUM> may taper outwardly from the annulus section <NUM> to the aortic section <NUM>. Each of the sections of the stent <NUM> includes a plurality of cells <NUM> connected to one another in one or more annular rows around the stent. For example, as shown in <FIG>, the annulus section <NUM> may have two annular rows of complete cells <NUM> and the aortic section <NUM> and transition section <NUM> may each have one or more annular rows of partial cells <NUM>. The cells <NUM> in the aortic section <NUM> may be larger than the cells <NUM> in the annulus section <NUM>. The larger cells in the aortic section <NUM> better enable the prosthetic valve <NUM> to be positioned without the stent structure interfering with blood flow to the coronary arteries.

Stent <NUM> may include one or more retaining elements <NUM> at the outflow end <NUM> thereof, the retaining elements being sized and shaped to cooperate with female retaining structures provided on the deployment device. The engagement of retaining elements <NUM> with the female retaining structures on the deployment device helps maintain prosthetic heart valve <NUM> in assembled relationship with the deployment device, minimizes longitudinal movement of the prosthetic heart valve relative to the deployment device during unsheathing or resheathing procedures, and helps prevent rotation of the prosthetic heart valve relative to the deployment device as the deployment device is advanced to the target location and during deployment.

The prosthetic heart valve <NUM> includes a valve assembly <NUM> positioned in the annulus section <NUM>. Valve assembly <NUM> includes a cuff <NUM> and a plurality of leaflets <NUM> which collectively function as a one-way valve. The commissure between adjacent leaflets <NUM> may be connected to commissure features <NUM> on stent <NUM>. Prosthetic heart valve <NUM> is shown in <FIG> with three leaflets <NUM>, as well as three commissure features <NUM>. As can be seen in <FIG>, the commissure features <NUM> may lie at the intersection of four cells <NUM>, two of the cells being adjacent one another in the same annular row, and the other two cells being in different annular rows and lying in end-to-end relationship. Preferably, commissure features <NUM> are positioned entirely within annulus section <NUM> or at the juncture of annulus section <NUM> and transition section <NUM>. Commissure features <NUM> may include one or more eyelets which facilitate the suturing of the leaflet commissure to the stent. However, it will be appreciated that the prosthetic heart valves may have a greater or lesser number of leaflets and commissure features. For example, a prosthetic mitral valve may include two prosthetic leaflets with two commissures. Additionally, although cuff <NUM> is shown in <FIG> as being disposed on the luminal surface of annulus section <NUM>, it is contemplated that the cuff may be disposed on the abluminal surface of annulus section <NUM>, or may cover all or part of either or both of the luminal and abluminal surfaces of annulus section <NUM>. Both the cuff <NUM> and the leaflets <NUM> may be wholly or partly formed of any suitable biological material or polymer.

In operation, a prosthetic heart valve, including the prosthetic heart valve described above, may be used to replace a native heart valve, such as the aortic valve, a surgical heart valve or a heart valve that has undergone a surgical procedure. The prosthetic heart valve may be delivered to the desired site (e.g., near a native aortic annulus) using any suitable delivery device, including the delivery devices described in detail below. During delivery, the prosthetic heart valve is disposed inside the delivery device in the collapsed condition. The delivery device may be introduced into a patient using a transfemoral, transapical or transseptal approach, although any transcatheter approach may suitable. Once the delivery device has reached the target site, the user may deploy the prosthetic heart valve. Upon deployment, the prosthetic heart valve expands into secure engagement within the native aortic annulus. When the prosthetic heart valve is properly positioned inside the heart, it works as a one-way valve, allowing blood to flow in one direction and preventing blood from flowing in the opposite direction.

In a prosthetic aortic heart valve, the valve assembly may be spaced from the outflow or aortic end of the stent by a distance that enables deployment of the heart valve by an amount sufficient for the valve leaflets of the prosthetic valve to operate as intended, while the outflow end of the stent remains captured by the delivery device. More particularly, the inflow or annulus end of the prosthetic heart valve may be deployed first, while the aortic or outflow end of the prosthetic heart valve remains at least partially covered by a distal sheath of the delivery device. The annulus portion of the prosthetic heart valve may be deployed so that the entirety of the valve leaflets, up to and including the commissures, is deployed and fully operational. By deploying the prosthetic heart valve in this manner, the user can determine whether the valve leaflets are properly positioned relative to the native valve annulus, and whether the valve is functioning properly. If the user determines that the positioning and operation of the valve are acceptable, the remainder of the valve may be deployed. However, if it is determined that the leaflet position is improper or that the valve is not functioning properly, the user may resheathe the valve and either reposition it for redeployment, or remove it entirely from the patient.

As is shown in <FIG>, in one embodiment the entirety of valve assembly <NUM>, including the leaflet commissures, is positioned in the annulus section <NUM> of stent <NUM>. When opened, the leaflets may extend further into the transition section <NUM> or may be designed such that they remain substantially completely within the annulus section. That is, substantially the entirety of valve assembly <NUM> is positioned between the inflow end <NUM> of stent <NUM> and the commissure features <NUM>, and none of the valve assembly <NUM> is positioned between commissure features <NUM> and the outflow end <NUM> of the stent. Indeed, in some embodiments, the valve can be designed such that, upon partial deployment, the commissure features are fully exposed, oriented generally parallel to the direction of blood flow, and at or near their actual radially expanded positions (but not necessarily their eventual positions relative to the annulus), such that the leaflets can operate substantially as they would when the valve is fully deployed, even though enough of the stent is still retained within the delivery device or sheath to permit resheathing.

In one arrangement, the distance between commissure features <NUM> and the outflow end <NUM> of stent <NUM> will be about two-thirds of the length of the stent from the inflow end <NUM> to the outflow end. This structural arrangement may provide advantages in the deployment of prosthetic valve <NUM> as will be discussed in more detail with reference to <FIG>. By having the entirety of valve assembly <NUM> positioned within annulus section <NUM>, and by having a sufficient distance between commissure features <NUM> and the distal end <NUM> of stent <NUM>, the valve assembly and commissures will not impede blood flow into the coronary arteries and will not interfere with access thereto during cardiac intervention, such as angiography, annuloplasty or stent placement.

Further, it is possible to partially deploy prosthetic valve <NUM> so that the valve assembly <NUM> thereof is able to fully function in its intended position in the native valve annulus, while a sufficient amount of the aortic section <NUM> is retained within the delivery device should resheathing become necessary. In other words, the user may withdraw the distal sheath of the delivery device to gradually expose prosthetic valve <NUM>, beginning at the inflow end <NUM>. Continued withdrawal of the distal sheath will expose a greater extent of the prosthetic valve until the entire annulus section <NUM> and valve assembly <NUM> have been exposed. Upon exposure, these portions of the prosthetic valve will expand into engagement with the native valve annulus, entrapping the native valves, except for a small portion immediately adjacent the free end of the distal sheath which will be constrained by the distal sheath from fully expanding.

However, once the distal sheath has been withdrawn to expose a sufficient portion of the aortic section <NUM>, the annulus section <NUM> will be able to fully expand and valve assembly <NUM> will be able to function in the same manner as if the entirety of prosthetic valve <NUM> had been deployed. At this juncture, it will be possible for the user to ascertain whether annulus section <NUM> and valve assembly <NUM> have been properly positioned relative to the native valve annulus, and whether the valve assembly is functioning properly.

If the position and operation of valve assembly <NUM> are acceptable, the distal sheath may be withdrawn further to deploy the remainder of prosthetic valve <NUM>. On the other hand, if the positioning or operation of valve assembly <NUM> are unacceptable, the user may advance the distal sheath to resheathe the prosthetic valve, reposition the valve and initiate the deployment procedure anew. And if it is determined that the valve is not functioning properly, it can be withdrawn from the patient and a new valve introduced.

It will be appreciated from the foregoing that the placement of the leaflets <NUM> within the stent <NUM> can affect the valve functioning during partial deployment. <FIG> illustrates a valve assembly <NUM> with high placement, while <FIG> illustrates a valve assembly with low placement. As used herein, the phrase "high placement" of a valve assembly refers to locating the valve assembly within the transition section <NUM> of the stent <NUM>, or within the portion of the annulus section <NUM> closest to the transition section. The phrase "low placement" of a valve assembly refers to locating the valve assembly closer to the inflow end <NUM> of the stent <NUM> and entirely within the annulus section <NUM> thereof, such that the leaflets <NUM> are substantially disposed within the annulus section.

As seen in <FIG>, during partial deployment the annulus end of the heart valve <NUM> is unsheathed and allowed to expand. The outflow end <NUM>, including the aortic section <NUM>, remains partially sheathed and coupled to the delivery device. It should be appreciated that high placement of valve assembly <NUM> will cause the valve assembly to not be fully deployed when heart valve <NUM> is only partially deployed, thereby affecting leaflet function. Specifically, since the commissure features <NUM> are located closer to or within the transition section <NUM>, they do not reach their fully expanded positions. As such, the leaflets <NUM> remain partially closed at this stage of deployment. Because of the location of the commissure features <NUM> and the leaflets <NUM>, the valve assembly <NUM> cannot be tested during partial deployment. Instead, the user must unsheathe a portion of the aortic section <NUM> as well, which may pose problems if the valve assembly <NUM> is to be resheathed and redeployed.

In contrast to the prosthetic heart valve of <FIG>, the heart valve <NUM> of <FIG> exhibits low placement of the valve assembly <NUM> within the annulus section <NUM>. Low placement of the valve assembly <NUM> enables the valve assembly to fully deploy when heart valve <NUM> is only partially deployed. As such, leaflets <NUM> reach their fully expanded and open positions during partial deployment and are able to function near normally, enabling a better assessment of the valve's functioning and final placement within the actual anatomy. Thus, if it appears that the valve needs to be moved, the heart valve <NUM> may be easily resheathed and repositioned. This concept is beneficial when dealing with less than ideal anatomical configurations.

The shape of the stent <NUM> during partial deployment will also affect the valve <NUM>. If the stent shape is such that, while still partially retained by the sheath, it cannot open sufficiently to allow operation of the valve, it may not be possible to fully assess the operation of the valve in its intended placement position. Moreover, the height of the valve commissure features <NUM> relative to the inflow end <NUM> of the valve will affect the valve function. The lower the commissure features <NUM>, meaning the closer to the inflow end <NUM>, the more they will expand outwardly and the valve leaflets will be able to open during partial deployment, creating a flow passageway through the leaflets which approaches that of a fully deployed valve.

A transfemoral or transapical delivery device may be used to partially deploy the prosthetic heart valve such that an assessment may be made regarding flow through the valve and adequacy of coaptation. If, after the annulus section is unsheathed and the valve is tested, it is found that the valve needs to be repositioned, the annulus section may be resheathed and the valve redeployed as necessary.

Turning now to <FIG>, an exemplary transfemoral delivery device <NUM> for a collapsible prosthetic heart valve (or other types of self-expanding collapsible stents) has a catheter assembly <NUM> for delivering the heart valve to and deploying the heart valve at a target location, and an operating handle <NUM> for controlling deployment of the valve from the catheter assembly. The delivery device <NUM> extends from a proximal end <NUM> to a distal tip <NUM>. The catheter assembly <NUM> is adapted to receive a collapsible prosthetic heart valve (not shown) in a compartment <NUM> defined around an inner shaft <NUM> and covered by a distal sheath <NUM>. The inner shaft <NUM> extends through the operating handle <NUM> to the distal tip <NUM> of the delivery device, and includes a retainer <NUM> affixed thereto at a spaced distance from distal tip <NUM> and adapted to hold a collapsible prosthetic valve in the compartment <NUM>.

The distal sheath <NUM> surrounds the inner shaft <NUM> and is slidable relative to the inner shaft such that it can selectively cover or uncover the compartment <NUM>. The distal sheath <NUM> is affixed at its proximal end to an outer shaft <NUM>, the proximal end of which is connected to the operating handle <NUM>. The distal end <NUM> of the distal sheath <NUM> abuts the distal tip <NUM> when the distal sheath fully covers the compartment <NUM>, and is spaced apart from the distal tip <NUM> when the compartment <NUM> is at least partially uncovered.

The operating handle <NUM> is adapted to control deployment of a prosthetic valve located in the compartment <NUM> by permitting a user to selectively slide the outer shaft <NUM> proximally or distally relative to the inner shaft <NUM>, or to slide the inner shaft <NUM> relative to the outer shaft <NUM>, thereby respectively uncovering or covering the compartment with the distal sheath <NUM>. Operating handle <NUM> includes frame <NUM> which extends from a proximal end <NUM> to a distal end and includes a top frame portion 1030a and a bottom frame portion 1030b. The proximal end of the inner shaft <NUM> is coupled to a hub <NUM>, and the proximal end of the outer shaft <NUM> is affixed to a carriage assembly within the frame <NUM> that is slidable within the operating handle along a longitudinal axis of the frame <NUM>, such that a user can selectively slide the outer shaft relative to the inner shaft by sliding the carriage assembly relative to the frame. Alternatively, inner shaft <NUM> may be actuated via hub <NUM> to cover or uncover the compartment, for example for rapid covering or uncovering of the compartment <NUM>. Optionally, a stability sheath <NUM> is disposed over some or all of outer shaft <NUM>. The stability sheath <NUM> may be attached to the outer shaft <NUM> or may be unattached. Additionally, stability sheath <NUM> may be disposed over a majority of outer shaft <NUM> or over a minority of the outer shaft (e.g., over <NUM>% or less, over <NUM>%, etc.). Optionally, stability sheath <NUM> may be more rigid than outer shaft <NUM>.

Additionally, hub <NUM> may include a pair of buttons, each attached to a clip. These clips on hub <NUM> may mate with voids on frame <NUM> to ensure that the hub and the frame are securely coupled together. Optionally, hub <NUM> may also include a wheel <NUM> which may assist in reducing strain in the distal sheath <NUM> when loading the prosthetic heart valve into the delivery device <NUM>.

A first mechanism for covering and uncovering the compartment <NUM> will be referred to as a "fine" technique as covering and uncovering occurs slowly with a high degree of precision. The "fine" movement may be provided by rotating a deployment wheel or actuator <NUM>, which may cause the carriage to pull or push the outer sheath <NUM> (and thus the distal sheath <NUM>) proximally or distally. The second mechanism for covering and uncovering the compartment <NUM> may be referred to as a "coarse" technique, by pulling or pushing the hub <NUM> as described above. The "coarse" technique may be particularly suited for use when a prosthetic heart valve is not positioned within the compartment <NUM>. The delivery device may also include a resheathing lock <NUM>, which may restrict motion of the distal sheath <NUM> once full deployment of the prosthetic heart valve is imminent. The resheathing lock <NUM> may be disengaged when the desired position of the prosthetic heart valve is confirmed, so that the distal sheath <NUM> may be further retracted to full release the prosthetic heart valve. In other words, the resheathing lock <NUM> may help prevent unintentional or premature complete deployment of the prosthetic heart valve. Additional features of the delivery device <NUM>, for example including the function of wheel <NUM>, are described in greater detail in <CIT>.

As noted above, it is often desirable for the commissures of the prosthetic heart valve to align rotationally with the commissures of the native heart valve upon deployment and /or implantation of the prosthetic heart valve into the native heart valve. Generally, such alignment may be approached from an active or passive standpoint. Active alignment generally refers to the inclusion of some mechanism that the user can activate or otherwise actively use to increase the likelihood of commissure alignment, for example by actively rotating the prosthetic heart valve until the prosthetic commissures are rotationally aligned with the native commissures. Passive alignment, on the other hand, generally referrers to the inclusion of some mechanism or design that allows the prosthetic heart valve commissures to rotationally align with the native heart valve commissures without the user actively inducing such alignment. The description below generally focuses on passive commissure-to-commissure alignment mechanisms and designs. It should be understood that although various passive commissure-to-commissure alignment mechanisms are described below, more than one of the mechanisms may be provided in a single system.

Certain embodiments below focus on features that exploit the geometry of the aortic arch and/or the aortic root. Features that exploit the geometry of the aortic arch may be particularly useful when transfemoral retrograde delivery is employed, since transfemoral delivery typically includes advancing the prosthetic heart valve and delivery device up and around the aortic arch, and then into or adjacent the native aortic valve. Features that exploit the geometry of the aortic root may be useful in any delivery approach. Further, it should be understood that any of the features that exploit the aortic root geometry may be applicable to passive commissure-to-commissure alignment in other prosthetic heart valves, such as the tricuspid or pulmonary valve. And even though the mitral valve typically has two leaflets while the aortic valve typically has three leaflets, the passive commissure-to-commissure alignment mechanisms that rely on aortic root or valve geometry may apply with similar or equal force to commissure-to-commissure alignment in mitral valve replacements.

<FIG> is a highly schematic side view of a delivery device during a transfemoral approach to implant a prosthetic aortic valve, with the delivery device traversing the aortic arch AA and a distal end of the delivery device positioned within or adjacent the native aortic valve AV. The delivery device may be similar or identical to delivery device <NUM>, with certain additions. However, it should be understood that the concepts described may be used in connection with delivery devices other than delivery device <NUM>, and the use of the same part numbers for the delivery device in <FIG> is purely for convenience. Due to the shape of the aortic arch AA, and due to the stiffness of a given delivery system (such as delivery device <NUM>), the distal end of the delivery device tends to sit at the outer curvature of the aortic arch AA. The native aortic valve AV typically includes three leaflets, including the left coronary cusp LCC, the right coronary cusp RCC, and the non-coronary cusp NCC, with the left coronary artery LCA and right coronary artery RCA extending from the aorta at a location just downstream the native aortic valve AV. The relative positions of these leaflets are illustrated in <FIG>, which is a cross-section taken through a plane that traverses the native aortic valve AV and the descending aortic arch AA. The native commissures are also illustrated in <FIG>, at the junction of adjacent ones of the leaflets. Due to the geometry of the aortic arch AA and the stiffness of the delivery device <NUM>, as noted above, during transfemoral delivery the distal sheath <NUM> and distal tip <NUM> of the delivery device <NUM> tends to follow the outer curvature of the aortic arch AA. The commissure between the right coronary cusp RCC and the non-coronary cusp NCC tends to correspond to this outer curvature location. Thus, as shown in <FIG>, the distal end of the delivery device will tend to generally be positioned near this commissure during a transfemoral delivery procedure. It should be understood that the leaflets of the native valve annulus AV is illustrated in the open condition (during ventricular systole) in <FIG>.

The delivery device <NUM> illustrated in <FIG> include an additional feature that may result in a predictable bend orientation (for example by preferentially bending in one direction) when the delivery device is in the position shown in <FIG>. This additional feature may help ensure that the distal sheath <NUM> housing the prosthetic heart valve (such as prosthetic heart valve <NUM> or any other expandable prosthetic heart valve) will have a predictable rotational orientation with respect to the native valve commissures. In the illustrated example, delivery device <NUM> includes a spine <NUM> running along a length thereof. In particular, delivery device <NUM> may include a spine <NUM> that has a stiffness that is greater than the stiffness of the outer shaft <NUM>. The spine <NUM> may be positioned on the outer diameter of the outer shaft <NUM>, or otherwise may be embedded within the wall forming the outer shaft <NUM>. In either case, the spine <NUM> may also extend along the distal sheath <NUM>, including the entire distal sheath or just a portion thereof. The spine <NUM> preferably extends at least along the portion of the outer shaft <NUM> that will be situated within the aortic arch AA during deployment of the prosthetic heart valve. However, referring to <FIG>, the spine <NUM> may extend any additional distance proximally toward the handle <NUM>, including the entire length of the outer shaft <NUM>.

In one example, the spine <NUM> may formed of a metal, metal alloy, or polymer (or combinations thereof) that is stiffer than the material forming the remainder of the outer shaft <NUM>. The spine <NUM> may have a lobster-tail configuration, for example in which the spine <NUM> is formed of individual plates or plate-like members in which the leading end of one plate overlaps (or is overlapped by) the trailing end of the adjacent plate. These plates forming spine <NUM> may be rectangular in cross-section, or may be generally rectangular in cross-section with a slight curvature that generally follows the circumferential contour of the outer shaft <NUM>. However, other shapes of these plates may be suitable for use in spine <NUM>. It should be understood that the overlapping nature of these plates may result in the spine <NUM> more easily bending in one desired direction than the opposite direction, as interference between the adjacent plates will be greater in one bend direction compared to the opposite bend direction. In other words, the spine <NUM> may preferentially bend so that it is located on the outer radius of the bend. As an alternative or in addition, the spine <NUM> may be formed of a shape-memory material (whether in the form of overlapping plates, or in the form of a single continuous wire or other similar member). If formed of shape-memory material, such as a nickel titanium alloy like nitinol, the spine <NUM> may be heat-set (or otherwise set) so that the spine <NUM> is biased toward bending in one direction compared to other directions. If spine <NUM> is in the form of a single continuous member, it may have a rectangular or circular, or oval cross-section, although other shapes may be suitable. The shape-setting may be performed so that the spine <NUM> begins to transition (or attempt to transition) to its shape-set contour upon exposure to temperatures found in the body. With this configuration, the spine <NUM> may be relatively straight prior to insertion into the body, but after insertion into the body, as the ambient body temperature causes the temperature of spine <NUM> to increase, the spine <NUM> may begin to transition (or attempt to transition) to its set curvature or set contouring.

In either of these embodiments, it is already known that the outer shaft <NUM> (and/or the distal sheath <NUM>) will tend to be positioned adjacent the native commissure between the right coronary cusp RCC and the non-coronary cusp NCC. By providing the delivery device <NUM> with spine <NUM> that imparts a preferential bend contour, the delivery device <NUM> will tend to have a known rotational orientation when in position for deployment of the prosthetic heart valve. In other words, because the spine <NUM> is configured to preferentially bend along the outer curvature of the aortic arch AA, when the delivery device <NUM> is in the position shown in <FIG>, the spine <NUM> will be in or adjacent the native commissure between the right coronary cusp RCC and non-coronary cusp NCC, with the spine <NUM> confronting the commissure. Thus, both the spatial position and rotational orientation of the outer shaft <NUM> (and/or delivery sheath <NUM>) will be known with respect to the native aortic valve AV. With this knowledge, the prosthetic heart valve <NUM> (or any other expandable prosthetic heart valve) may be loaded into the compartment <NUM> of the delivery sheath <NUM> with one of the prosthetic leaflet commissures rotationally aligned with the position of the spine <NUM>. Thus, after achieving the position illustrated in <FIG>, the distal sheath <NUM> may be withdrawn to allow the prosthetic heart valve <NUM> to expand into the native aortic valve AV. This relative positioning will result in the prosthetic commissure originally rotationally aligned with the spine <NUM> being rotationally aligned with the native commissure between the right coronary cusp RCC and then non-coronary cusp NCC after deployment. Further, it should be understood that if one of the prosthetic commissures is rotationally aligned with one of the native commissures, the remaining prosthetic commissures will be generally in rotational alignment with the remaining native commissures.

Although any suitable method may be used to help ensure that one of the commissures of the prosthetic heart valve <NUM> is aligned with the spine <NUM> during loading of the prosthetic heart valve into the delivery device <NUM>, one particular method may rely on the positions of the retainers <NUM> of the delivery device. As described above, the prosthetic heart valve <NUM> may be held in a desired axial and rotational position within the compartment <NUM> due to the retaining elements <NUM> of the prosthetic heart valve being received in corresponding retainers <NUM>. Referring back to <FIG>, each of the three retainers <NUM> is axially aligned with one of the prosthetic commissures, which are positioned at the commissure attachment features <NUM> of the stent <NUM>. Thus, if the spine <NUM> is rotationally aligned with one of the retainers <NUM>, the prosthetic heart valve <NUM> will have one of the prosthetic commissures aligned with the spine <NUM> during loading due to the relative positioning of the retainers <NUM>, the retaining elements <NUM>, and the commissure attachment features <NUM>.

While <FIG> focus on a spine <NUM> positioned on or adjacent an outer diameter of the outer shaft <NUM> and/or distal sheath <NUM> of the delivery device <NUM>, <FIG> illustrate a related concept where a spine is positioned on an interior of the delivery device. In particular, <FIG> illustrate a spine 3000a having a rectangular cross-section, whereas spine 3000b has a generally circular cross-section. Spines 3000a-b may be formed of a relatively rigid material that extends a length along the delivery device <NUM>, similar to that described in connection with spine <NUM>, but positioned on the interior of the outer shaft <NUM>. Spines 3000a-b generally serve the same overall purpose as spine <NUM> to induce preferential bending of the outer shaft <NUM> around the aortic arch AA. Spines 3000a-b may be formed of a metal, metal alloy, polymer, or combinations thereof that are preferably more rigid and/or stiff than the outer shaft <NUM>, and may extend a length relative to the inner shaft <NUM> similar to that described in connection with spine <NUM>. The preferential bending may be induced by shape-memory setting of the spines 3000a-b and/or by the geometry and position of the spines 3000a-b relative to the remainder of the outer shaft <NUM>. For example, the spines 3000a-b may be shape-set in substantially the same manner described above in connection with spine <NUM>. Whether or not the spines 3000a-b are shape-set, they may include geometries and positions that induce a particular bend. For example, spine 3000a may have a rectangular cross section transverse its length. This rectangular shape will cause spine 3000a to preferentially bend so that the longer sides of the rectangular are positioned on the inner and outer tracks of the bend, while the shorter sides are positioned on either side of the bend. The spine 3000a may be positioned generally centered along the center longitudinal axis of the outer shaft <NUM>. <FIG> also illustrates the rotational positions of the prosthetic commissures (or retaining elements <NUM>, retainers <NUM>, or commissure attachment features <NUM>) when the prosthetic heart valve <NUM> is within the delivery device <NUM>. As can be seen in <FIG>, one of the prosthetic commissures is positioned generally centered along one of the longer sides of the rectangular cross-section of the spine 3000a. With this relative positioning, one of the longer sides of the spine 3000a will tend to confront the native commissure, as shown in <FIG>, and thus one of the prosthetic commissures will tend to rotationally align with the native commissure between the right coronary cusp RCC and the non-coronary cusp NCC. Thus, when loading the prosthetic heart valve <NUM> (or any other prosthetic heart valve) into the delivery sheath <NUM>, the prosthetic heart valve is preferably loaded so that one of the prosthetic commissures is in rotational alignment with the longer side of the spine 3000a that will tend to confront the native commissure. As with the embodiments above, this can be achieved, for example, by aligning the retainers <NUM> in the desired rotational orientation relative to the spine 3000a.

Now referring to <FIG>, spine 3000b may function generally similar to spine 3000a, with two main differences. First, spine 3000b may have a generally circular cross-section. However, if spine 3000b does not include shape-setting, it would may induce any preferential bending if the center longitudinal axis of the spine 3000b was coincident with the central longitudinal axis of the outer shaft <NUM>. Instead, the central longitudinal axis of the spine 3000b may be offset from the central longitudinal axis of the outer shaft <NUM>. In particular, by offsetting these central longitudinal axes, the outer shaft <NUM> will tend to bend so that the spine 3000b is positioned closer to the outer radius of the bend than the inner radius of the bend. Thus, the prosthetic heart valve should be loaded into the distal sheath <NUM> so that one of the prosthetic commissures is generally rotationally aligned with the point along the spine 3000b that is closest in distance to the outer shaft <NUM>. As with the embodiments above, this can be achieved, for example, by aligning the retainers <NUM> in the desired rotational orientation relative to the spine 3000b. It should be understood that the delivery of the prosthetic heart valve <NUM> (whether using spine 3000a or 3000b) may be otherwise substantially the same as that described in connection with <FIG>. The embodiments described in connection with <FIG> may be best suited for transfemoral aortic valve replacement, at least in part because these embodiments rely on the curvature of the aortic arch AA to passively achieve the desired commissures-to-commissure alignment. Further, it should be understood that any of the spines described above maybe substantially or completely solid members.

While the embodiments described in connection with <FIG> mainly leverage the shape and contours of the aortic arch AA, the embodiments described below in connection with <FIG> may rely on the geometry of the aortic root (including the native aortic valve AV) to achieve the desired commissure-to-commissure alignment, although the shape of the aortic arch AA may also be implicated in these embodiments.

The embodiments of <FIG> include a delivery device <NUM> that may be similar or identical to that described in connection with <FIG>, with certain differences. <FIG> illustrates a cross-section of the distal sheath <NUM> of the delivery device <NUM> positioned within the native aortic valve AV while the valve leaflets are open (e.g. during ventricular systole), while <FIG> provides the same illustration but after the leaflets are closed (e.g. during ventricular diastole). As shown in <FIG>, the distal sheath <NUM> may include a fin-like protrusion <NUM> extending radially outward therefrom. Protrusion <NUM> may extend a length along the distal sheath <NUM>, for example at least about <NUM>%, at least about <NUM>%, at least about <NUM>%, at least about <NUM>%, or the entire length of the distal sheath <NUM>. The protrusion <NUM> may extend a length radially outwardly from the outer surface of the distal sheath <NUM> that is about the same diameter of the distal sheath <NUM>, although in other embodiments length may be greater or smaller than the diameter of the distal sheath <NUM>. Preferably, the protrusion <NUM> is formed of a material similar to that of the distal sheath <NUM>, although other materials may be suitable. In some embodiments, the protrusion <NUM> may be integral with the distal sheath <NUM>, and in other embodiments the protrusion <NUM> may be formed separately and coupled to the distal sheath <NUM>. In some embodiments, the protrusion <NUM> may be formed as an inflatable member, similar to valvuloplasty balloons, so that the protrusion <NUM> can be inflated via saline or other solution when in the desired position, reducing the overall profile of the distal sheath <NUM> during delivery and prior to the use of the protrusion <NUM>. The protrusion <NUM> preferably does not extend proximal to the distal sheath <NUM> to the outer shaft <NUM>, although in some embodiments that extension may be suitable.

As is described in greater detail below in connection with <FIG>, the delivery device <NUM> shown in connection with <FIG> may include features that allow the distal sheath <NUM> to rotated with respect to the outer shaft <NUM>, for example where the outer shaft <NUM> transitions to the distal sheath <NUM>. Referring back to <FIG>, when the distal sheath <NUM> is positioned within the native aortic valve AV, the protrusion <NUM> is also positioned within the native aortic valve AV. As with the earlier embodiments described in connection with <FIG>, if the delivery route is transfemoral and through the aortic arch AA, the distal sheath <NUM> will tend to be positioned at or near the commissure between the right coronary cusp RCC and the non-coronary cusp NCC. When in this position, the protrusion <NUM> extends radially inwardly, generally pointing away from the native commissure between the right coronary cusp RCC and the non-coronary cusp NCC, although the exact direction may depend on various factors during the delivery. As the heart continues to beat, the leaflets of the native aortic valve AV will be forced closed during ventricular diastole, as shown in <FIG>. As the leaflets coapt, the right coronary cusp RCC and the non-coronary cusp NC will attempt to close over the distal sheath <NUM> and the protrusion <NUM>. Because the distal sheath <NUM> is rotatable relative to the outer shaft <NUM>, the force of the leaflets closing over the protrusion <NUM> will tend to rotate the distal sheath <NUM> so that the protrusion <NUM> extends along the line of coaptation between the right coronary cusp RCC and the non-coronary cusp NCC. This position is illustrated in <FIG>, with the radial end of the protrusion <NUM> pointing toward the longitudinal center of the native aortic valve AV.

Similar to earlier embodiments, with the configuration described in connection with <FIG>, the spatial position of the distal sheath <NUM> will generally be known (i.e. in or near the native commissure between the right coronary cusp RCC and the non-coronary cusp NCC) at least in part due to the tendency of the delivery device to hug the outer radius of the aortic arch AA. Further, the rotational position of the distal sheath <NUM> will be known due to the forced repositioning of the protrusion <NUM> to orient along the line of coaptation toward the valve center. Thus, the prosthetic heart valve <NUM> (or any other suitable prosthetic heart valve) can be loaded into the distal sheath <NUM> with the prosthetic commissures in a particular desired rotational orientation. For example one of the prosthetic commissures may be positioned diametrically opposed to the point where the protrusion <NUM> contacts (or extends from) the distal sheath <NUM>. With this configuration, when the distal sheath <NUM> is in the position and orientation shown in <FIG>, one of the prosthetic commissures will rotationally align with the native commissure between the right coronary cusp RCC and the non-coronary cusp NCC. Thus, as the distal sheath <NUM> is withdrawn to allow the prosthetic heart valve <NUM> to self-expand (or to expand via a balloon or similar mechanism), the native and prosthetic commissures will be in rotational alignment. As with other embodiments, the prosthetic heart valve <NUM> may be loaded into the distal sheath <NUM> with the desired orientation in any suitable manner, including by positioning the protrusion <NUM> diametrically opposed one of the retainers <NUM>. The process of implanting the prosthetic heart valve <NUM> may be otherwise similar or the same as described for embodiments above.

<FIG> illustrate a delivery device <NUM> that is generally similar to that described in connection with <FIG>, with certain differences. The main difference is that, while the embodiment shown in connection with <FIG> includes a relatively long (in radial extension) and thin protrusion <NUM>, the embodiment of <FIG> include a distal sheath <NUM> that has a non-symmetric cross-sectional shape with a protrusion <NUM> that has a shape complementary to the native commissure. Referring to <FIG>, the protrusion <NUM> on the distal sheath <NUM> may be positioned only on the distal sheath <NUM> and may not extend proximally to the outer shaft <NUM> beyond the point where the outer shaft <NUM> transitions to the distal sheath <NUM>. As is described in greater detail below, the distal sheath <NUM> may be rotatable relative to the outer shaft <NUM>, similar to the embodiment described in connection with <FIG>. Preferably, the protrusion <NUM> is integrally formed with the distal sheath <NUM>, and may have the shape of a slight triangular protrusion extending from an otherwise circular cross-section, as shown in <FIG>. The protrusion <NUM> may be significantly smaller than protrusion <NUM> in radial extension, but significant longer than protrusion <NUM> in axial extension. For example, the length of the protrusion may be about half, less than half, or less than one fourth the diameter of the distal sheath <NUM> (where the diameter of the distal sheath <NUM> is exclusive of the protrusion <NUM>). The shape and size of the protrusion <NUM> may be generally complementary to (or a negative of) the shape the native commissure between the right coronary cusp RCC and the non-coronary cusp NCC. As noted above, if a transfemoral delivery route is used, the traversal of the aortic arch AA may generally cause the distal sheath <NUM> to be positioned near or adjacent the native commissure, as shown in <FIG>. If the protrusion <NUM> does not initially nest into the native commissure, the freedom of the distal sheath <NUM> to rotate will result in the distal sheath <NUM> rotating until the protrusion <NUM> fits into the native commissure, like a puzzle piece, as shown in <FIG>. Once the protrusion <NUM> nests within the native commissure, the puzzle-like fitment will prevent the distal sheath <NUM> from additional rotation, effectively locking the rotation position of the distal sheath <NUM> relative to the native aortic valve AV during deployment of the prosthetic heart valve <NUM>.

Once the distal sheath <NUM> is positioned within the native valve annulus AV and the protrusion <NUM> has rotated into fitment with the native commissure, the distal sheath <NUM> may be retracted to deploy the prosthetic heart valve <NUM> while the position and rotational orientation of the prosthetic heart valve are in the desired relation to the native commissures. In particular, the prosthetic heart valve <NUM> (or any other suitable prosthetic heart valve) is loaded into the distal sheath <NUM> with one of the prosthetic commissures in rotational alignment with the protrusion <NUM>. With this configuration, one of the prosthetic commissures will be in rotational alignment with the native commissure between the right coronary cusp RCC and the non-coronary cusp NCC, while the other two prosthetic commissures will be in rotational alignment with the other two native commissures on completion of deployment. As with the other embodiments described herein, the prosthetic heart valve <NUM> may be loaded into the distal sheath <NUM> with the desired orientation in any desirable fashion, including by positioning the protrusion <NUM> in radial alignment with one of the retainers <NUM>. The remainder of the delivery and deployment of the prosthetic heart valve may be similar or identical to that described in connection with other embodiments above.

The embodiments described in connection with <FIG> rely, in part, on the ability of the distal sheath <NUM> to rotate with respect to the outer shaft <NUM> while the delivery device <NUM> is positioned at or near the native aortic valve AV. Such rotation may be achieved via any suitable mechanism. <FIG> illustrates the delivery device <NUM> including a joint J between the outer shaft <NUM> and the distal sheath <NUM>. The joint J may take the form of a rotary bearing, such as a thrust bearing, that allows for rotation of the outer sheath <NUM> in one rotational direction R or in both rotational directions about the longitudinal axis of the outer shaft <NUM>, as shown in <FIG>. However, it should be understood that other rotational joints J may be suitable other than thrust bearings. In some embodiments, it may be preferable to have friction about the j oint J so that, while the distal sheath <NUM> can rotate, the rotation is not totally free. For example, referring back to <FIG>, the joint J needs to be able to rotate toward the valve center when the leaflets close on the protrusion <NUM>. However, when the leaflets open again during ventricular systole, it may be preferable for some resistance in the joint J to help maintain the rotational position of the protrusion when the leaflets are not actively pushing the protrusion.

<FIG> illustrates another embodiment of the delivery device <NUM> that may assist in passive commissure-to-commissure alignment, particularly in stenotic native aortic valves AV. <FIG> illustrates a delivery device similar to that described in connection with <FIG>, including a joint J that allows rotation between the distal sheath <NUM> and the outer shaft <NUM>. The main difference in the embodiment shown in <FIG> is that the distal sheath <NUM> includes a fin <NUM>. The fin <NUM> may be thin and may protrude radially outward from the distal sheath <NUM>. The fin <NUM> may be shaped so that the distance is ramped in a proximal to distal direction. In other words, the radial distance which the fin <NUM> extends from the distal sheath <NUM> may increase from the distal end of the fin <NUM> towards the proximal end of the fin <NUM>. In the particular illustrated embodiment, the fin <NUM> first ramps outwardly from the outer sheath <NUM>, and then maintain that distance for a length. This shape may be particularly useful in stabilizing the fin <NUM> as fluid (i.e. blood) flows over the fin <NUM>, as described in greater detail below.

<FIG> illustrates a highly schematic cross section of a stenotic aortic valve AV with three stenotic leaflets SL during ventricular systole. The relatively high level of stenosis of the leaflets SL results in a relatively small effective orifice area EOA when the leaflets are open. This difference can be qualitatively seen by comparing the open stenotic leaflets SL of the aortic valve AV of <FIG> with the size and shape of the open area of the aortic valve in <FIG>. This smaller effective orifice area EOA may result in a higher velocity of blood through the aortic valve during ventricular systole, although it should be understood that the embodiment described in connection with <FIG> may be suitable for use in aortic valve AV that have less stenosis than that shown in <FIG>.

<FIG> illustrates the aortic valve AV of <FIG> with the distal sheath <NUM> positioned substantially aligned with the center of the aortic valve AV, and with the fin <NUM> positioned slightly downstream of the stenotic leaflets SL. When the aortic valve AV is open, the area of high velocity blood flow HF is restricted to the center area, with the remainder area having low velocity blood flow LF, as indicated in <FIG>. As the blood flows through the aortic valve AV while the fin <NUM> is positioned just downstream the stenotic leaflets SL, the shape of the particular fin <NUM> illustrated in <FIG> and <FIG> will result in the fin <NUM> orienting to a low flow position. For example, as shown in <FIG>, forces F from the high flow area HF will tend to push the fin <NUM> away from the high flow HF zones until the fin <NUM> stabilizes in a low flow area LF. In this particular embodiment, the fin <NUM> is preferably positioned a spaced distance from the distal tip <NUM> so that, when the distal sheath <NUM> is within the aortic valve AV, the closing of the stenotic leaflets SL does not contact the fin <NUM> and does not cause the distal sheath <NUM> to rotate. When loading the prosthetic heart valve <NUM> (or any other suitable heart valve) within the distal sheath <NUM>, one of the prosthetic commissures may be positioned diametrically opposed to the location of the fin <NUM>. Thus, when the fin <NUM> is in the position shown in <FIG>, one of the prosthetic commissures is rotationally aligned with the bottom of the aortic valve AV in the view of <FIG>, which is where one of the native commissures is positioned. Upon deploying the prosthetic heart valve <NUM>, then, the prosthetic commissures will rotationally align with corresponding native commissures.

Although one shape of fin <NUM> is illustrated, other shapes may be used to position the fin into a high flow area HF, a low flow area LF, or to cause the fin to rotate until it contacts one of the leaflets. For example, if the fin has a wedge, funnel, or shovel shape, the fin would tend to align away from the high flow HF areas and to settle in a low flow LF area, similar to the view of <FIG>. An umbrella or airfoil shape, on the other hand, would tend to cause the fin to move toward and settle in a high flow HF area. If the fin has one of these shapes to align with a high flow HF area, one of the prosthetic commissures should be aligned with the fin (instead of diametrically opposed from the fin) when the valve is loaded into the distal sheath <NUM>. In the above embodiments, the fins are preferably positioned just downstream and clear of the leaflets so that the leaflet closing does not interfere with the leaflets. However, in other embodiments, the fins may be positioned so that the leaflets can contact the fin to further assist with the alignment. In other embodiments, the fin can be angled or have a corkscrew shape so that, as blood flows over the fin, the fin initiates rotation in the delivery system capsule/compartment. In this embodiment, the fin is preferably in an axial position so that the delivery system capsule will rotate until it makes contact with one of the native leaflets forcing the delivery system into the native commissure.

While many of the embodiments above focus on features related to the delivery device to assist in commissure-to-commissure alignment, in other embodiments, the prosthetic heart valve <NUM> may include features that assist in commissure-to-commissure alignment. For example, prosthetic heart valve <NUM> may be provided with a particular shape during deployment that may be useful in providing the desired commissure-to-commissure alignment. <FIG> illustrate prosthetic heart valve <NUM> mid-deployment from the distal sheath <NUM>, with the inflow end <NUM> of the prosthetic heart valve <NUM> transitioning to the expanded condition, and the outflow end <NUM> still maintained within the distal sheath in a collapsed condition, for example via connection of retaining elements <NUM> to retainers <NUM>. As can be best seen in <FIG>, prosthetic heart valve <NUM> is configured to take a particular shape during deployment. In <FIG>, the shape is generally triangular, with the points of the triangle shape being aligned with the prosthetic commissures C of the valve (and with the commissure attachment features <NUM> and/or retaining elements <NUM>). The profile of the prosthetic heart valve <NUM> may include curved or concave contours between adjacent commissures C while the prosthetic heart valve <NUM> is partially deployed. Preferably, if the prosthetic heart valve <NUM> includes the above-described shape (or any similar shape) mid-deployment, the distal sheath <NUM> is rotatable relative to the outer shaft <NUM>, similar to as described above, for example in connection with <FIG>. With this configuration, as the prosthetic heart valve <NUM> is deployed from the distal sheath <NUM>, the profile of the inflow end <NUM> of the prosthetic heart valve has a shape that generally corresponds to the native aortic valve AV while the inflow end <NUM> is positioned at least partially within the native aortic valve AV. As the native leaflets close during ventricular diastole, the leaflets will tend to try to push against the contoured surfaces of the prosthetic heart valve <NUM> between adjacent commissures C. Because the distal sheath <NUM>, and thus the prosthetic heart valve <NUM>, is capable of rotating relative to the outer shaft <NUM>, when the native leaflets push against the inflow end <NUM> of the prosthetic heart valve <NUM>, they will tend to force the prosthetic heart valve <NUM> into alignment with the native aortic valve geometry. In other words, the commissures C of the prosthetic heat valve <NUM> will tend to rotationally align with the native commissures due to the forces applied on the prosthetic heart valve <NUM> by the native leaflets closing.

It should be understood that, while the configuration of the partial deployment shape of the prosthetic heart valve <NUM> described in connection with <FIG> may be useful for passive commissure-to-commissure alignment, it may also be useful for active commissure-to-commissure alignment. For example, if the delivery device <NUM> is provided with a mechanism to actively rotate the distal sheath <NUM>, the partially deployed valve can be actively rotated until it is in the desired rotational orientation (which may be confirmed, for example, under fluoroscopy), and then rotation of the distal sheath <NUM> may then be locked so that the prosthetic heart valve <NUM> is unable to rotate out of the desired orientation during the remainder of deployment.

While the partially deployed shape shown and described in connection with <FIG> is generally triangular, other shapes may be suitable. For example, an egg shape (in the view of <FIG>) may also produce similar results, with the narrow end of the "egg" shape tending to rotated toward a commissure. Thus, in that embodiment, one of the prosthetic commissures would be positioned in radial alignment with the narrow point of the egg shape. However, other partial deployment shapes may also be suitable as long as those shapes tend to self-rotate (or allow for active rotation) into a predictable position relative to the native commissures.

The above-described shapes of the prosthetic heart valve <NUM> during partial deployment may be achievably by any suitable means. In one example, the prosthetic heart valve <NUM> may be tethered to the delivery device <NUM>, with the tethers applying force to constrain the prosthetic heart valve into the desired partial deployment shape. For example, tethers such as sutures may be attached to the stent of the prosthetic heart valve near the middle of the concave curvature sections of <FIG> and extend up through the delivery device <NUM> so that tension on the tethers restricts the expansion of the inwardly contoured sections. The tethers may be cut or may have a reversible looping system in order to release the tethers from the prosthetic heart valve <NUM> after implantation is complete. In another embodiment, a plurality of arms may extend distally from the distal sheath <NUM> (e.g. from the outer surface of the distal sheath <NUM>), with the arms configured to press inwardly on the prosthetic heart valve <NUM> during deployment. For example, in connection with the embodiment of <FIG>, three arms may extend distally from the distal sheath <NUM> to contact the outer surface of the prosthetic heart valve <NUM> during deployment to block the contact portions from fully expanding while the contact is maintained. With this configuration, the arms may rotate in sync with the distal sheath <NUM> as deployment progresses and the prosthetic heart valve <NUM> rotates into commissural alignment with the native heart valve. It should be understood that as deployment continues and the distal sheath <NUM> is withdrawn further, the arms move out of contact with the prosthetic valve and allow the prosthetic valve <NUM> to fully expand. If arms are included to force the desired mid-deployment shape, those arms may be retractable into the delivery device so as to not interfere with the anatomy during delivery or withdrawal of the delivery device. In another embodiment, the delivery device <NUM> may include a secondary distal sheath or sleeve positioned distal to distal sheath <NUM>. The secondary distal sheath may include recesses or other elements to hold certain struts of the inflow end of the prosthetic heart valve <NUM> to constrict those portions of the prosthetic valve from expanding. For example, referring to back to <FIG>, the secondary distal sheath could capture the terminal inflow struts of stent <NUM> (e.g. the horse-shoe shaped terminal struts ends) at circumferential locations between the commissure attachment features <NUM>, while the terminal inflow struts directly circumferentially adjacent the commissure attachment features <NUM> could be free to self-expand. With this configuration, the constraining of the retained terminal inflow struts and the freedom of the non-retained terminal inflow struts will allow the inflow end <NUM> of the prosthetic heart valve <NUM> to self-expand into a shape similar to that shown in <FIG> mid-deployment. Once the prosthetic heart valve <NUM> is in the desired alignment, the retained terminal inflow struts may be released from the secondary distal sheath, for example by sliding the secondary distal sheath distally to allow the prosthetic heart valve <NUM> to fully expand.

Although various individual features for passive commissure-to-commissure alignment are described herein, it should be understood that some of the features may be combinable into a single system. For example, the use of the desired partial-deployment shapes described in connection with <FIG> could be combined with any of the delivery device features for commissure-to-commissure alignment described above - particularly those that include rotation of the distal sheath. And still other features could be combined, such as the use of an outer spine similar to that described in connection with <FIG> along with an inner spine similar to that described in connection with <FIG>.

Further, although much of the disclosure above is described in connection with a transfemoral approach to an aortic valve replacement, the invention is not so limited. For example, any of the embodiments that rely on a particular partial deployment shape may be used in any valve replacement, although it should be understood that the particular partial deployment shape may be tailored to the particular heart valve being replaced. Thus, the partial deployment shape(s) described may be suitable for any of the tricuspid valves (e.g. aortic, pulmonary, or tricuspid valves), while a different shape may be suitable for use in a bicuspid valve replacement (e.g. mitral valve). Similarly, for any of the embodiments that rely on contact between the native leaflets and the delivery device, or high and low velocity blood flow zones to achieve commissure-to-commissure alignment, those embodiments may be suitable for use in any heart valve replacement and via any transcatheter delivery approach. And still further, even for the embodiments that rely upon the particular geometry of the aortic arch to assist with commissure-to-commissure alignment, the concepts described in connection with those embodiments may be modified to achieve similar results in other valve replacement procedures, or even in aortic valve replacement procedures that utilized approaches other than transfemoral delivery.

Claim 1:
A delivery device (<NUM>) for a collapsible prosthetic heart valve (<NUM>), the delivery device comprising:
an inner shaft (<NUM>);
an outer shaft (<NUM>);
a distal sheath (<NUM>) disposed distal to the outer shaft and about a portion of the inner shaft to form a compartment (<NUM>) with the inner shaft, the compartment being sized to receive the prosthetic heart valve, the inner shaft and the distal sheath being movable relative to one another, the outer shaft and the distal sheath sharing a central longitudinal axis;
wherein the outer shaft is joined to the distal sheath via a joint (J) so that the distal sheath is capable of rotation about the central longitudinal axis while the outer shaft remains static relative to the central longitudinal axis
characterised in that the distal sheath includes a flat protrusion (<NUM>, <NUM>, <NUM>) extending a length radially outward therefrom, and forces on the flat protrusion tend to rotate the distal sheath about the central longitudinal axis and relative to the outer shaft about the joint.