Patent Description:
The present disclosure relates to implantable, mechanically expandable prosthetic devices, such as prosthetic heart valves, and to methods and delivery assemblies for, and including, such devices.

The human heart can suffer from various valvular diseases. These valvular diseases can result in significant malfunctioning of the heart and ultimately require repair of the native valve or replacement of the native valve with an artificial valve. There are a number of known repair devices (e.g., stents) and artificial valves, as well as a number of known methods of implanting these devices and valves in humans. Percutaneous and minimally-invasive surgical approaches are used in various procedures to deliver prosthetic medical devices to locations inside the body that are not readily accessible by surgery or where access without surgery is desirable. In one specific example, a prosthetic heart valve can be mounted in a crimped state on the distal end of a delivery apparatus and advanced through the patient's vasculature (e.g., through a femoral artery and the aorta) until the prosthetic heart valve reaches the implantation site in the heart. The prosthetic heart valve is then expanded to its functional size, for example, by inflating a balloon on which the prosthetic valve is mounted, actuating a mechanical actuator that applies an expansion force to the prosthetic heart valve, or by deploying the prosthetic heart valve from a sheath of the delivery apparatus so that the prosthetic heart valve can self-expand to its functional size.

Prosthetic heart valves that rely on a mechanical actuator for expansion can be referred to as "mechanically expandable" prosthetic heart valves. Mechanically expandable prosthetic heart valves can provide one or more advantages over self-expandable and balloon-expandable prosthetic heart valves. For example, mechanically expandable prosthetic heart valves can be expanded to various diameters. Mechanically expandable prosthetic heart valves can also be compressed after an initial expansion (e.g., for repositioning and/or retrieval).

Despite the recent advancements in percutaneous valve technology, there remains a need for improved transcatheter heart valves and delivery devices for such valves.

<CIT> relates to a prosthetic valve comprising a radially expandable and compressible frame, which can include a plurality of struts which are pivotally joined together without requiring individual rivets. In some embodiments, the struts are interwoven, and can be joined using integral hinges formed in the struts, such as by performing alternate cuts on the struts, bending the struts to form stopper tabs adjacent to joints and/or drilling holes in the struts to facilitate interconnecting struts at joints, or otherwise forming integral hinges and corresponding holes at junction points between the struts. In another embodiment, the frame comprises a plurality of inner struts and outer struts which are connected by a plurality of chains of interconnected rivets, avoiding the need to provide individual rivets at each junction between struts, In still another embodiment, separate hinges are provided to interconnect the struts. In still another embodiment, separate flanged rivets are provided to connect the struts.

Aspects of the presently claimed invention are set out in the independent claim. Any methods contained herein do not fall within the scope of the appended claims but are considered as being useful for understanding the invention.

Embodiments of improved prosthetic implant delivery assemblies and frames therefor are disclosed herein, as well as related methods and devices for such assemblies. In several embodiments, the disclosed assemblies are configured for delivering replacement heart valves into a heart of a patient.

A first aspect of the presently claimed invention provides an implantable prosthetic device comprising a frame movable between a radially compressed and a radially expanded configuration, the frame comprising an inflow end portion and an outflow end portion, the frame comprising a plurality of struts, and at least one expansion and locking mechanism. The at least one expansion and locking mechanism comprises a first member coupled to the frame at a first location, a second member coupled to the frame at a second location spaced apart from the first location, the second member extending at least partially into the first member, and a third member having a first end portion and a second end portion, the first end portion extending at least partially into the first member and the second end portion comprising an engagement portion. The plurality of struts includes a first strut and a second strut pivotably coupled to one another to form an apex, the first strut comprising a first flange and the second strut comprising a second flange. When the frame is in the expanded configuration, advancement of the third member in a distal direction positions the engagement member between the first and second flanges such that the first and second flanges engage the engagement member to resist pivoting of the first and second struts relative to one another in a first direction to resist radial compression of the frame.

A second aspect of the presently claimed embodiment provides an assembly comprising a prosthetic heart valve and a delivery apparatus. The prosthetic heart valve comprises a frame movable between a radially compressed and a radially expanded configuration, the frame comprising an inflow end portion and an outflow end portion, the frame comprising a first strut and a second strut comprising a first flanged portion and a second flanged portion respectively, and at least one expansion and locking mechanism. The at least one expansion and locking mechanism comprises a first member coupled to the frame at a first location, a second member coupled to the frame at a second location spaced apart from the first location, the second member extending at least partially into the first member, and a third member comprising an engagement portion. The delivery apparatus can comprise a handle, a first actuation member extending from the handle and coupled to the first member, the first actuation member configured to apply a distally directed force to the first member, a second actuation member extending from the handle and coupled to the second member, the second actuation member configured to apply a proximally directed force to the second member, and a third actuation member extending from the handle and coupled to the third member. The prosthetic heart valve can be radially expandable from the radially compressed configuration to the radially expanded configuration upon application of at least one of the first distally directed force and the proximally directed force to the prosthetic heart valve via the first and second actuation members, respectively. When the prosthetic heart valve is in the radially expanded configuration the engagement portion of the third member selectively engages the first and second flanges to prevent compression of the frame.

Also disclosed herein, but not forming part of the presently claimed invention, is a method which can comprise inserting a distal end of a delivery apparatus into the vasculature of a patient, the delivery apparatus releasably coupled to a prosthetic heart valve movable between a radially compressed and a radially expanded configuration. The prosthetic valve can comprise a frame comprising an inflow end portion, an outflow end portion, and a plurality of struts, and an expansion and locking mechanism comprising a first member coupled to the frame at a first location, a second member coupled to the frame at a second location spaced apart from the first location, and a third member having a first end portion and a second end portion comprising an engagement portion. The method can further comprise advancing the prosthetic valve to a selected implantation site, moving at least one of the first member distally and the second member proximally to radially expand the prosthetic valve, and advancing the third member distally such that the engagement portion engages one or more flanges radially extending from respective struts of the plurality of struts to lock the prosthetic valve in an expanded configuration.

Also disclosed herein is an implantable prosthetic device which comprises a frame movable between a radially compressed and a radially expanded configuration, the frame comprising an inflow end portion, an outflow end portion, and a plurality of struts including a first strut and a second strut pivotably coupled to one another to form an apex, the first strut comprising a first flange and the second strut comprising a second flange. The frame further comprises one or more expansion and locking mechanisms comprising a first member coupled to the frame at a first location, a second member coupled to the frame at a second location, the second member extending at least partially into the first member, and a third member extending at least partially into the second member and comprising an engagement portion. The second member can comprise a biasing member configured to bias the engagement portion of the third member toward the inflow end of the frame. When the frame is in the expanded configuration advancement of the third member in a distal direction via the biasing member positions the engagement member between the first and second flanges such that the first and second flanges engage the engagement member to resist pivoting of the first and second struts relative to one another in a first direction to resist radial compression of the frame.

Also disclosed herein is an assembly which can comprise a prosthetic heart valve and a delivery apparatus. The prosthetic heart valve comprises a frame movable between a radially compressed and a radially expanded configuration, the frame comprising an inflow end portion, an outflow end portion, and a first strut and a second strut comprising a first flanged portion and a second flanged portion respectively. The frame further comprises an expansion and locking mechanism comprising a first member, a second member, and a third member. The first member is coupled to the frame at a first location, the second member is coupled to the frame at a second location spaced apart from the first location and can comprise a biasing member configured to bias an engagement portion of the third member toward the inflow end of the frame. The delivery apparatus can comprise a handle, a first actuation member extending from the handle and coupled to the first member, the first actuation member configured to apply a distally directed force to the first member, and a second actuation member extending from the handle and coupled to the second member, the second actuation member configured to apply a proximally directed force to the second member. The prosthetic heart valve is radially expandable from the radially compressed configuration to the radially expanded configuration upon application of at least one of the first distally directed force and the proximally directed force to the prosthetic heart valve via the first and second actuation members, respectively. When the prosthetic heart valve is in the expanded configuration, advancement of the third member in a distal direction via the biasing member positions the engagement member between the first and second flanged portions such that the first and second flanged portions engage the engagement member to resist pivoting of the first and second struts relative to one another in a first direction to resist radial compression of the frame.

The foregoing and other objects, features, and advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

The presently claimed invention relates to a prosthetic heart valve as illustrated in <FIG>.

Described herein are examples of prosthetic implant delivery assemblies and components thereof which can improve a physician's ability to control the size of a mechanically-expandable prosthetic implant, such as prosthetic valves (e.g., prosthetic heart valves or venous valves), stents, or grafts, as well as facilitate separation of the prosthetic implant from the delivery assembly, during the implantation procedure. The present disclosure also provides frames for use with such prosthetic implants. The frames can comprise expansion and locking mechanisms configured to expand and/or compress the frame and to hold the frame in an expanded configuration when the implant is expanded at a selected delivery site within a patient.

Prosthetic valves disclosed herein can be radially compressible and expandable between a radially compressed state and a radially expanded state. Thus, the prosthetic valves can be crimped on or retained by an implant delivery apparatus in the radially compressed state during delivery, and then expanded to the radially expanded state once the prosthetic valve reaches the implantation site. It is understood that the valves disclosed herein may be used with a variety of implant delivery apparatuses, and examples thereof will be discussed in more detail later.

<FIG> shows an exemplary prosthetic valve <NUM>, according to one embodiment. The prosthetic valve <NUM> includes an annular stent or frame <NUM> having an inflow end <NUM> and an outflow end <NUM>. The prosthetic valve <NUM> can also include a valvular structure <NUM> which is coupled to and supported inside of the frame <NUM>. The valvular structure <NUM> is configured to regulate the flow of blood through the prosthetic valve <NUM> from the inflow end <NUM> to the outflow end <NUM>.

The valvular structure <NUM> can include, for example, a leaflet assembly comprising one or more leaflets <NUM> made of a flexible material. The leaflets <NUM> can be made from in whole or part, biological material, bio-compatible synthetic materials, or other such materials. Suitable biological material can include, for example, bovine pericardium (or pericardium from other sources). The leaflets <NUM> can be secured to one another at their adjacent sides to form commissures, each of which can be secured to a respective actuator <NUM> or the frame <NUM>.

In the depicted embodiment, the valvular structure <NUM> comprises three leaflets <NUM>, which can be arranged to collapse in a tricuspid arrangement. Each leaflet <NUM> can have an inflow edge portion <NUM>. As shown in <FIG>, the inflow edge portions <NUM> of the leaflets <NUM> can define an undulating, curved scallop shape that follows or tracks a plurality of interconnected strut segments of the frame <NUM> in a circumferential direction when the frame <NUM> is in the radially expanded configuration. The inflow edges of the leaflets can be referred to as a "scallop line.

In some embodiments, the inflow edge portions <NUM> of the leaflets <NUM> can be sutured to adjacent struts of the frame generally along the scallop line. In other embodiments, the inflow edge portions <NUM> of the leaflets <NUM> can be sutured to an inner skirt, which in turn in sutured to adjacent struts of the frame. By forming the leaflets <NUM> with this scallop geometry, stresses on the leaflets <NUM> are reduced, which in turn improves durability of the valve <NUM>. Moreover, by virtue of the scallop shape, folds and ripples at the belly of each leaflet <NUM> (the central region of each leaflet), which can cause early calcification in those areas, can be eliminated or at least minimized. The scallop geometry also reduces the amount of tissue material used to form valvular structure <NUM>, thereby allowing a smaller, more even crimped profile at the inflow end <NUM> of the valve <NUM>.

Further details regarding transcatheter prosthetic heart valves, including the manner in which the valvular structure can be mounted to the frame of the prosthetic valve can be found, for example, in <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>, <CIT> and <CIT>.

The prosthetic valve <NUM> can be radially compressible and expandable between a radially compressed configuration and a radially expanded configuration. <FIG> show the bare frame <NUM> of the prosthetic valve <NUM> (without the leaflets and other components) for purposes of illustrating expansion of the prosthetic valve <NUM> from the radially compressed configuration (<FIG>) to the radially expanded configuration (<FIG>).

The frame <NUM> can include a plurality of interconnected lattice struts <NUM> arranged in a lattice-type pattern and forming a plurality of apices <NUM> at the outflow end <NUM> of the prosthetic valve <NUM>. The struts <NUM> can also form similar apices <NUM> at the inflow end <NUM> of the prosthetic valve <NUM>. In <FIG>, the struts <NUM> are shown as positioned diagonally, or offset at an angle relative to, and radially offset from, a longitudinal axis <NUM> of the prosthetic valve <NUM> when the prosthetic valve <NUM> is in the expanded configuration. In other implementations, the struts <NUM> can be offset by a different amount than depicted in <FIG>, or some or all of the struts <NUM> can be positioned parallel to the longitudinal axis <NUM> of the prosthetic valve <NUM>.

The struts <NUM> can comprise a set of inner struts 24a (extending from the lower left to the upper right of the frame in <FIG>) and a set of outer struts 24b (extending from the upper left to the lower right of the frame in <FIG>) connected to the inner struts 24a. The open lattice structure of the frame <NUM> can define a plurality of open frame cells <NUM> between the struts <NUM>.

The struts <NUM> can be pivotably coupled to one another at one or more pivot joints or pivot junctions <NUM> along the length of each strut. For example, in one embodiment, each of the struts <NUM> can be formed with apertures <NUM> at opposing ends of the strut and apertures spaced along the length of the strut. Respective hinges can be formed at the locations where struts <NUM> overlap each other via fasteners <NUM> (<FIG>), such as rivets or pins that extend through the apertures <NUM>. The hinges can allow the struts <NUM> to pivot relative to one another as the frame <NUM> is radially expanded or compressed, such as during assembly, preparation, or implantation of the prosthetic valve <NUM>.

The frame struts and the components used to form the pivot joints of the frame <NUM> (or any frames described below) can be made of any of various suitable materials, such as stainless steel, a cobalt chromium alloy, or a nickel titanium alloy ("NiTi"), for example Nitinol. In some embodiments, the frame <NUM> can be constructed by forming individual components (e.g., the struts and fasteners of the frame) and then mechanically assembling and connecting the individual components together. Further details regarding the construction of the frame and the prosthetic valve are described in <CIT> and <CIT>, <CIT> and <CIT>.

In the illustrated embodiment, the prosthetic valve <NUM> can be mechanically expanded from the radially contracted configuration to the radially expanded configuration. For example, the prosthetic valve <NUM> can be radially expanded by maintaining the inflow end <NUM> of the frame <NUM> at a fixed position while applying a force in the axial direction against the outflow end <NUM> toward the inflow end <NUM>. Alternatively, the prosthetic valve <NUM> can be expanded by applying an axial force against the inflow end <NUM> while maintaining the outflow end <NUM> at a fixed position, or by applying opposing axial forces to the inflow and outflow ends <NUM>, <NUM>, respectively.

As shown in <FIG>, the prosthetic valve <NUM> can include one or more actuators <NUM> mounted to and equally spaced around the inner surface of the frame <NUM>. Each of the actuators <NUM> can be configured to form a releasable connection with one or more respective actuators of a delivery apparatus.

In the illustrated embodiment, expansion and compression forces can be applied to the frame by the actuators <NUM>. Referring again to <FIG>, each of the actuators <NUM> can comprise a screw or threaded rod <NUM>, a first anchor in the form of a cylinder or sleeve <NUM>, and a second anchor in the form of a threaded nut <NUM>. The rod <NUM> extends through the sleeve <NUM> and the nut <NUM>. The sleeve <NUM> can be secured to the frame <NUM>, such as with a fastener <NUM> that forms a hinge at the junction between two struts. Each actuator <NUM> is configured to increase the distance between the attachment locations of a respective sleeve <NUM> and nut <NUM>, which causes the frame <NUM> to elongate axially and compress radially, and to decrease the distance between the attachment locations of a respective sleeve <NUM> and nut <NUM>, which causes the frame <NUM> to foreshorten axially and expand radially.

For example, each rod <NUM> can have external threads that engage internal threads of the nut <NUM> such that rotation of the rod causes corresponding axial movement of the nut <NUM> toward or away from the sleeve <NUM> (depending on the direction of rotation of the rod <NUM>). This causes the hinges supporting the sleeve <NUM> and the nut <NUM> to move closer towards each other to radially expand the frame or to move farther away from each other to radially compress the frame, depending on the direction of rotation of the rod <NUM>.

In other embodiments, the actuators <NUM> can be reciprocating type actuators configured to apply axial directed forces to the frame to produce radial expansion and compression of the frame. For example, the rod <NUM> of each actuator can be fixed axially relative to the sleeve <NUM> and slidable relative to the sleeve <NUM>. Thus, in this manner, moving the rod <NUM> distally relative to the sleeve <NUM> and/or moving the sleeve <NUM> proximally relative to the rod <NUM> radially compresses the frame. Conversely, moving the rod <NUM> proximally relative to the sleeve <NUM> and/or moving the sleeve <NUM> distally relative to the rod <NUM> radially expands the frame.

When reciprocating type actuators are used, the prosthetic valve can also include one or more locking mechanisms that retain the frame in the expanded state. The locking mechanisms can be separate components that are mounted on the frame apart from the actuators, or they can be a sub-component of the actuators themselves.

Each rod <NUM> can include an attachment member <NUM> along a proximal end portion of the rod <NUM> configured to form a releasable connection with a corresponding actuator of a delivery apparatus. The actuator(s) of the delivery apparatus can apply forces to the rods for radially compressing or expanding the prosthetic valve <NUM>. The attachment member <NUM> in the illustrated configuration comprises a notch <NUM> and a projection <NUM> that can engage a corresponding projection of an actuator of the delivery apparatus.

In the illustrated embodiments, the prosthetic valve <NUM> includes three such actuators <NUM>, although a greater or fewer number of actuators could be used in other embodiments. The leaflets <NUM> can have commissure attachments members <NUM> that wrap around the sleeves <NUM> of the actuators <NUM>. Further details of the actuators, locking mechanisms and delivery apparatuses for actuating the actuators can be found in <CIT> and <CIT>, and <CIT>. Any of the actuators and locking mechanisms disclosed in the previously filed applications can be incorporated in any of the prosthetic valves disclosed herein. Further, any of the delivery apparatuses disclosed in the previously filed applications can be used to deliver and implant any of the prosthetic valves discloses herein.

The prosthetic valve <NUM> can include one or more skirts or sealing members. In some embodiments, the prosthetic valve <NUM> can include an inner skirt (not shown) mounted on the inner surface of the frame. The inner skirt can function as a sealing member to prevent or decrease perivalvular leakage, to anchor the leaflets to the frame, and/or to protect the leaflets against damage caused by contact with the frame during crimping and during working cycles of the prosthetic valve. As shown in <FIG>, the prosthetic valve <NUM> can also include an outer skirt <NUM> mounted on the outer surface of the frame <NUM>. The outer skirt <NUM> can function as a sealing member for the prosthetic valve by sealing against the tissue of the native valve annulus and helping to reduce paravalvular leakage past the prosthetic valve. The inner and outer skirts can be formed from any of various suitable biocompatible materials, including any of various synthetic materials, including fabrics (e.g., polyethylene terephthalate fabric) or natural tissue (e.g., pericardial tissue). Further details regarding the use of skirts or sealing members in prosthetic valve can be found, for example, in <CIT>.

<FIG> show another embodiment of a prosthetic valve <NUM> comprising a frame <NUM> and expansion and locking mechanisms <NUM> (also referred to as "actuators"). It should be understood that the prosthetic valve <NUM> can include leaflets <NUM> and other soft components, such as one or more skirts <NUM>, which are removed for purposes of illustration. Expansion and locking mechanism <NUM> can be used to both radially expand and lock the prosthetic valve in a radially expanded state. In the example of <FIG>, three expansion and locking mechanisms <NUM> are attached to the frame <NUM> but in other example delivery assemblies, any number of expansion and locking mechanisms <NUM> can be used. <FIG> shows the expansion and locking mechanisms <NUM> attached to the frame <NUM> when the frame is in a radially collapsed configuration and <FIG> shows expansion and locking mechanisms attached to the frame when the frame is in a radially expanded configuration.

It will be appreciated that prosthetic valve <NUM> can, in certain embodiments, use other mechanisms for expansion and locking, such as linear actuators, alternate locking mechanisms, and alternate expansion and locking mechanisms. Further details regarding the use of linear actuators, locking mechanisms, and expansion and locking mechanisms in prosthetic valve can be found, for example, in <CIT>.

Referring to <FIG>, the expansion and locking mechanism <NUM> in the illustrated embodiment can include an actuator screw <NUM> (which functions as a linear actuator or a push-pull member in the illustrated embodiment) comprising a relatively long upper, or distal, portion <NUM> and a relatively shorter lower, or proximal, portion <NUM> at the proximal end of the screw <NUM>, wherein the lower portion has a smaller diameter than the upper portion. Both the upper and lower portions <NUM>, <NUM> of the screw <NUM> can have externally threaded surfaces.

The actuator screw <NUM> can have a distal attachment piece <NUM> attached to its distal end having a radially extending distal valve connector <NUM>. The distal attachment piece <NUM> can be fixed to the screw <NUM> (e.g., welded together or manufactured as one piece). The distal valve connector <NUM> can extend through an opening at or near the distal end of the frame <NUM> formed at a location on the frame where two or more struts intersect as shown in <FIG>. The distal valve connector <NUM> can be fixed to the frame <NUM> (e.g., welded). Due to the shape of the struts, the distal end of the frame <NUM> comprises an alternating series of distal junctions <NUM> and distal apices <NUM>. In the illustrated example, the distal valve connectors <NUM> of the three expansion and locking mechanisms <NUM> are connected to the frame <NUM> through distal junctions <NUM>. In other examples, one or more distal valve connectors <NUM> can be connected to the frame <NUM> through distal apices <NUM>. In other embodiments, the distal valve connectors <NUM> can be connected to junctions closer to the proximal end of the frame <NUM>.

The expansion and locking mechanism <NUM> can further include a sleeve <NUM>. The sleeve <NUM> can be positioned annularly around the distal portion <NUM> of the screw <NUM> and can contain axial openings at its proximal and distal ends through which the screw <NUM> can extend. The axial openings and the lumen in the sleeve <NUM> can have a diameter larger than the diameter of the distal portion <NUM> of the screw <NUM> such that the screw can move freely within the sleeve (the screw <NUM> can be moved proximally and distally relative to the sleeve <NUM>). Because the actuator screw <NUM> can move freely within the sleeve, it can be used to radially expand and/or contract the frame <NUM> as disclosed in further detail below.

The sleeve <NUM> can have a proximal valve connector <NUM> extending radially from its outer surface. The proximal valve connector <NUM> can be fixed to the sleeve <NUM> (e.g., welded). The proximal valve connector <NUM> can be axially spaced from the distal valve connector <NUM> such that the proximal valve connector can extend through an opening at or near the proximal end of the frame <NUM>. The proximal end of the frame <NUM> comprises an alternating series of proximal junctions <NUM> and proximal apices <NUM>. In the illustrated example, the proximal valve connectors <NUM> of the three expansion and locking mechanisms <NUM> are connected to the frame <NUM> through proximal junctions <NUM>. In other examples, one or more proximal valve connectors <NUM> can be connected to the frame <NUM> through proximal apices <NUM>. In other embodiments, the proximal valve connectors <NUM> can be connected to junctions closer to the distal end of the frame <NUM>.

It should be understood that the distal and proximal connectors <NUM>, <NUM> need not be connected to opposite ends of the frame. The actuator <NUM> can be used to expand and compress the frame as long as the distal and proximal connectors are connected to respective junctions on the frame that are axially spaced from each other.

A locking nut <NUM> can be positioned inside of the sleeve <NUM> and can have an internally threaded surface that can engage the externally threaded surface of the actuator screw <NUM>. The locking nut <NUM> can have a notched portion <NUM> at its proximal end, the purpose of which is described below. The locking nut can be used to lock the frame <NUM> into a particularly radially expanded state, as discussed below.

<FIG> and <FIG> shows the expansion and locking mechanism <NUM> including components of a delivery apparatus not shown in <FIG>. As shown, the expansion and locking mechanism <NUM> can be releasably coupled to a support tube <NUM>, an actuator member <NUM>, and a locking tool <NUM>. The proximal end of the support tube <NUM> can be connected to a handle or other control device (not shown) that a doctor or operator of the delivery assembly utilizes to operate the expansion and locking mechanism <NUM> as described herein. Similarly, the proximal ends of the actuator member <NUM> and the locking tool <NUM> can be connected to the handle.

The support tube <NUM> annularly surrounds a proximal portion of the locking tool <NUM> such that the locking tool extends through a lumen of the support tube. The support tube <NUM> and the sleeve are sized such that the distal end of the support tube abuts or engages the proximal end of the sleeve <NUM> such that the support tube is prevented from moving distally beyond the sleeve.

The actuator member <NUM> extends through a lumen of the locking tool <NUM>. The actuator member <NUM> can be, for example, a shaft, a rod, a cable, or wire. The distal end portion of the actuator member <NUM> can be releasably connected to the proximal end portion <NUM> of the actuator screw <NUM>. For example, the distal end portion of the actuator member <NUM> can have an internally threaded surface that can engage the external threads of the proximal end portion <NUM> of the actuator screw <NUM>. Alternatively, the actuator member <NUM> can have external threads that engage an internally threaded portion of the screw <NUM>. When the actuator member <NUM> is threaded onto the actuator screw <NUM>, axial movement of the actuator member causes axial movement of the screw.

The distal portion of the locking tool <NUM> annularly surrounds the actuator screw <NUM> and extends through a lumen of the sleeve <NUM> and the proximal portion of the locking tool annularly surrounds the actuator member <NUM> and extends through a lumen of the support tube <NUM> to the handle of the delivery device. The locking tool <NUM> can have an internally threaded surface that can engage the externally threaded surface of the locking screw <NUM> such that clockwise or counter-clockwise rotation of the locking tool <NUM> causes the locking tool to advance distally or proximally along the screw, respectively.

The distal end of the locking tool <NUM> can comprise a notched portion <NUM>, as can best be seen in <FIG>. The notched portion <NUM> of the locking tool <NUM> can have an engagement surface <NUM> that is configured to engage a correspondingly shaped engagement surface <NUM> of the notched portion <NUM> of the locking nut <NUM> such that rotation of the locking tool (e.g., clockwise rotation) causes the nut <NUM> to rotate in the same direction (e.g., clockwise) and advance distally along the locking screw <NUM>. The notched portions <NUM>, <NUM> in the illustrated embodiment are configured such that rotation of the locking tool <NUM> in the opposite direction (e.g., counter-clockwise) allows the notched portion <NUM> of the tool <NUM> to disengage the notched portion <NUM> of the locking nut <NUM>; that is, rotation of the locking tool in a direction that causes the locking tool to move proximally does not cause corresponding rotation of the nut.

In alternative embodiments, the distal end portion of the locking tool <NUM> can have various other configurations adapted to engage the nut <NUM> and produce rotation of the nut upon rotation of the locking tool for moving the nut distally, such as any of the tool configurations described herein. In some embodiments, the distal end portion of the locking tool <NUM> can be adapted to produce rotation of the nut <NUM> in both directions so as move the nut distally and proximally along the locking screw <NUM>.

In operation, prior to implantation, the actuator member <NUM> is screwed onto the proximal end portion <NUM> of the actuator screw <NUM> and the locking nut <NUM> is rotated such that it is positioned at the proximal end of the screw. The frame <NUM> can then be placed in a radially collapsed state and the delivery assembly can be inserted into a patient. Once the prosthetic valve is at a desired implantation site, the frame <NUM> can be radially expanded as described herein.

To radially expand the frame <NUM>, the support tube <NUM> is held firmly against the sleeve <NUM>. The actuator member <NUM> is then pulled in a proximal direction through the support tube, such as by pulling on the proximal end of the actuator member or actuating a control knob on the handle that produces proximal movement of the actuator member. Because the support tube <NUM> is being held against the sleeve <NUM>, which is connected to a proximal end of the frame <NUM> by the proximal valve connector <NUM>, the proximal end of the frame is prevented from moving relative to the support tube. As such, movement of the actuator member <NUM> in a proximal direction causes movement of the actuator screw <NUM> in a proximal direction (because the actuator member is threaded onto the screw), thereby causing the frame <NUM> to foreshorten axially and expand radially. Alternatively, the frame <NUM> can be expanded by moving the support tube <NUM> distally while holding the actuator member <NUM> stationary or moving the support tube distally while moving the actuator member <NUM> proximally.

After the frame <NUM> is expanded to a desired radially expanded size, the frame can be locked at this radially expanded size as described herein. Locking the frame can be achieved by rotating the locking tool <NUM> in a clockwise direction causing the notched portion <NUM> of the locking tool to engage the notched portion <NUM> of the locking nut <NUM>, thereby advancing the locking nut distally along the actuator screw <NUM>. The locking tool <NUM> can be so rotated until the locking nut <NUM> abuts an internal shoulder at the distal end of the sleeve <NUM> and the locking nut <NUM> cannot advance distally any further (see <FIG>). This will prevent the screw <NUM> from advancing distally relative to the sleeve <NUM> and radially compressing the frame <NUM>. However, in the illustrated embodiment, the nut <NUM> and the screw <NUM> can still move proximally through the sleeve <NUM>, thereby allowing additional expansion of the frame <NUM> either during implantation or later during a valve-in-valve procedure.

Once the frame <NUM> is locked in radially expanded state, the locking tool <NUM> can be rotated in a direction to move the locking tool proximally (e.g., in a counter-clockwise direction) to decouple the notched portion <NUM> from the notched portion <NUM> of the locking nut <NUM> and to unscrew the locking tool from the actuator screw <NUM>. Additionally, the actuator member <NUM> can be rotated in a direction to unscrew the actuator member from the lower portion <NUM> of the actuator screw <NUM> (e.g., the actuator member <NUM> can be configured to disengage from the actuator screw when rotated counter-clockwise). Once the locking tool <NUM> and the actuator member <NUM> are unscrewed from the actuator screw <NUM>, they can be removed from the patient along with the support tube <NUM>, leaving the actuator screw and the sleeve <NUM> connected to the frame <NUM>, as shown in <FIG>, with the frame <NUM> locked in a particular radially-expanded state.

In an alternative embodiment, the locking tool <NUM> can be formed without internal threads that engage the external threads of the actuator screw <NUM>, which can allow the locking tool <NUM> to be slid distally and proximally through the sleeve <NUM> and along the actuator screw <NUM> to engage and disengage the nut <NUM>.

In some embodiments, additional designs for expansion and locking mechanisms can be used instead of the design previously described. Details on expansion and locking mechanisms can be found, for example, in <CIT>.

<FIG> illustrate an exemplary embodiment of a prosthetic heart valve <NUM> comprising a frame <NUM> and one or more expansion and locking mechanisms <NUM>. Though the described embodiments refer to a mechanically expandable prosthetic valve having pivotably coupled struts, the expansion and locking mechanisms described herein can also be used with other mechanically expandable prosthetic valves, such as those described in <CIT>.

The frame <NUM> comprises a plurality of pivotably connected struts <NUM> defining an inflow end <NUM> (which is the distal end of the frame in the delivery configuration for the illustrated embodiment) and an outflow end <NUM> (which is the proximal end of the frame in the delivery configuration for the illustrated embodiment). The struts <NUM> are pivotably connected to each other at a plurality of junctions that permit pivoting of the struts relative to each other when the frame <NUM> is radially compressed and expanded, as described above in connection with prosthetic valves <NUM> and <NUM>.

The prosthetic valve <NUM> can include a valvular structure (e.g., valvular structure <NUM>) and inner and/or outer skirts, as previously described, although these components are omitted for purposes of illustration. While only a portion of the frame <NUM> is depicted in <FIG>, it should be appreciated that frame <NUM> forms an annular structure similar to frame <NUM> of prosthetic valve <NUM>. The one or more expansion and locking mechanisms <NUM> are used in lieu of or in addition to actuators <NUM> described above, and comprise a first or outer member <NUM>, a second or inner member <NUM>, and a third or locking member <NUM>. The expansion and locking mechanisms <NUM> can be used to radially expand the frame <NUM> and to lock the frame in a radially expanded state, as described in more detail below.

The frame <NUM> can comprise a plurality of inflow junctions or apices <NUM> at the inflow end portion <NUM> and a plurality of outflow junctions or apices <NUM> at the outflow end portion <NUM>. Selected inflow apices <NUM> can comprise one or more flanges <NUM> configured to engage the locking member <NUM> of the expansion and locking mechanism <NUM> to lock the prosthetic valve <NUM> in the radially expanded configuration. As shown in the illustrated embodiment, the expansion and locking mechanisms <NUM> can be circumferentially aligned with the selected inflow apices <NUM> comprising flanges <NUM>.

For example, <FIG> illustrate a selected inflow apex <NUM> comprising a first, radially inner strut 304a and a second, radially outer strut 304b. First strut 304a includes first flange 322a and second strut 304b includes second flange 322b. As the frame <NUM> expands, the first and second struts 304a, 304b (and therefore first and second flanges 322a, 322b), pivot relative to one another to define a gap G between them, as shown in <FIG>. Each flange 322a, 322b can comprise a respective axial portion 324a, 324b that extends axially past the junction of the first and second struts 304a, 304b, and a respective radial portion 326a, 326b (<FIG>) that extends radially inward toward a longitudinal axis of the prosthetic valve <NUM>. In other embodiments, the expansion and locking mechanisms <NUM> can be mounted on the outside of the frame <NUM> and the radial portions 326a, 326b can extend radially outward from the frame.

As best shown in <FIG>, the first axial portion 324a can have a length L<NUM> and the second axial portion 324b can have a length L<NUM>. The length L<NUM> can be greater than the length L<NUM>, or vice versa, such that when the frame <NUM> is in the radially compressed configuration (see e.g., <FIG>) the radial portions 326a, 326b can be circumferentially aligned with one another (meaning that their respective circumferential positions are aligned along a line that is parallel to a longitudinal axis of the frame). The differing lengths L<NUM> and L<NUM> of the axial portions 324a, 324b allow the flanges 322a, 322b to pivot relative to one another about inflow apex <NUM> without the radial portions 326a, 326b contacting or abutting one another.

Referring now to <FIG>, the first radial portion 326a can have a length L<NUM> and the second radial portion 326b can have a length L<NUM>. Length L<NUM> can be greater than length L<NUM> such that when the radial portions 326a, 326b are circumferentially aligned with one another both radial portions terminate at substantially the same radial location. In other words, neither radial portion extends past the other. In other embodiments, such as embodiments wherein second strut 304b is positioned radially inwards of first strut 304a, the length L<NUM> can be greater than the length L<NUM>.

While <FIG> show only a single expansion and locking mechanism <NUM> mounted to the frame <NUM>, it should be appreciated that the prosthetic valve <NUM> can comprise any number of expansion and locking mechanisms <NUM>. For example, in some embodiments, a prosthetic valve can comprise two expansion and locking mechanisms, or three expansion and locking mechanisms, or four expansion and locking mechanisms, etc. The expansion and locking mechanisms <NUM> can be placed at any position about the circumference of the frame <NUM>. For example, in some embodiments, the expansion and locking mechanisms <NUM> can be equally spaced from one another about the circumference of the frame <NUM>. In other embodiments, it can be advantageous to have two or more expansion and locking mechanisms <NUM> situated adjacent to one another.

Referring to <FIG>, as mentioned previously, each expansion and locking mechanism <NUM> includes a first, or outer member <NUM>, a second or inner member <NUM>, and a locking member <NUM>. The outer member <NUM> can comprise a first lumen or bore <NUM> (<FIG>) sized to receive at least a portion of the inner member <NUM>, and the inner member <NUM> can comprise a second lumen or bore <NUM> (<FIG>) sized to receive at least a portion of the locking member <NUM>. The outer member <NUM>, inner member <NUM>, and locking member <NUM>, can each move axially relative to one another.

As best shown in <FIG>, a distal end portion <NUM> of the inner member <NUM> can be coupled to the frame <NUM> at a first location via a fastener <NUM> that is affixed to and extends radially from the distal end portion <NUM> of the inner member <NUM>. The fastener can be, for example, a rivet or a pin. As shown, in some embodiments, the fastener <NUM> can extend through corresponding apertures at a junction of two overlapping struts <NUM> of frame <NUM> and can serve as a pivot pin around which the two struts <NUM> can pivot relative to one another and the inner member <NUM>. In some embodiments, an end cap or nut can be disposed over an end portion of the fastener <NUM> to retain the fastener within the corresponding apertures.

The outer member <NUM> can be coupled to the frame <NUM> at a second location, axially spaced from the first location. For example, in the illustrated embodiment, the inner member <NUM> is secured to the frame <NUM> near the distal or inflow end <NUM> of the frame and the outer member <NUM> is secured to the frame <NUM> closer to or at the proximal or outflow end <NUM> of the frame, such as via a fastener <NUM> (<FIG>), which can be, for example, a rivet or a pin. The fastener <NUM> is affixed to and extends radially from the outer member <NUM> through corresponding apertures at a junction of two overlapping struts <NUM> and can serve as a pivot pin around which the two struts <NUM> can pivot relative to each other and the outer member <NUM>. A nut can be mounted on each fastener <NUM> to retain the fastener within the corresponding apertures. The expansion and locking mechanism <NUM> can be coupled to the frame <NUM> at any two axially spaced, circumferentially aligned locations on the frame.

In alternative embodiments, the inner member and/or outer member <NUM>, <NUM> need not comprise fasteners <NUM>, <NUM> and can be coupled to the frame <NUM> via other means of attachment such as welding, adhesives, etc..

As shown in <FIG>, the inner member <NUM> can be axially movable relative to the outer member <NUM> in a proximal direction, as shown by arrow <NUM>, and in a distal direction, as shown by arrow <NUM>. As such, because the inner member <NUM> and the outer member <NUM> are secured to the frame <NUM> at axially spaced locations, moving the inner member <NUM> and the outer member <NUM> axially relative to one another in a telescoping manner causes radial expansion and/or compression of the frame <NUM>. For example, moving the inner member <NUM> proximally toward the outflow end <NUM> of the frame, as shown by arrow <NUM>, while holding the outer member <NUM> in a fixed position and/or moving the outer member <NUM> distally toward the inflow end <NUM> of the frame can cause the frame <NUM> to foreshorten axially and expand radially. Conversely, moving the inner member <NUM> distally in the direction of arrow <NUM> and/or moving the outer member <NUM> proximally causes the frame <NUM> to elongate axially and compress radially.

As best shown in <FIG>, outer member <NUM> can further comprise a recess <NUM>. The recess <NUM> can extend through a thickness of the outer member <NUM> and can extend to the distal edge <NUM> of the outer member. The recess <NUM> can be configured to limit the proximal advancement of the inner member <NUM> within the outer member <NUM>. For example, as the prosthetic valve <NUM> expands, the inner member <NUM> can slide relative to the outer member <NUM> such that the fastener <NUM> of the inner member <NUM> can slide within the recess <NUM>. The inner member <NUM> can continue moving relative to the outer member <NUM> until the fastener <NUM> abuts a proximal edge <NUM> of the recess <NUM>, restraining further motion of the inner member <NUM> relative to the outer member <NUM>.

The locking member <NUM> can have a first end portion <NUM> and a second end portion <NUM>. The first end portion <NUM> can have a circular shape in cross-section and can extend at least partially into the second bore <NUM> of the inner member <NUM>. The second end portion <NUM> can comprise an engagement member <NUM> configured to engage one or more portions of the frame <NUM> to lock the frame <NUM> in the expanded configuration and prevent compression of the frame, as described in more detail below.

In the illustrated embodiment, the engagement member <NUM> is configured as a wedge having a base portion <NUM> and an apical portion <NUM>. As shown in <FIG>, the base portion <NUM> can have a first width Wi that tapers to a second width W<NUM> at the apical portion <NUM>. The base portion <NUM> can comprise a shoulder <NUM> sized to abut a distal edge <NUM> of the second member <NUM>, thereby preventing movement of the locking member <NUM> relative to the second member <NUM> past a predetermined point.

As best shown in <FIG>, the engagement member <NUM> can have a first side wall <NUM> and a second side wall <NUM> inclined relative to one another at an angle α, also referred to as the "wedge angle. " The wedge angle α can be selected according to the following Equation <NUM>. In some embodiments, the wedge angle can be configured to correspond with a selected prosthetic valve diameter.

In some embodiments, the wedge angle α can be between about <NUM> degrees and about <NUM> degrees. For example, in particular embodiments, the wedge angle α can be between about <NUM> degrees and about <NUM> degrees. In some embodiments, the wedge angle α can be determined using the coefficient of friction between metals. For example, the static coefficient of wet friction for metals can be between about <NUM> to about <NUM>. If the tangent of the wedge angle is less than the coefficient of friction, the locking member <NUM> will remain in the locked position under the radial forces applied by the native aortic annulus.

In the illustrated embodiment, the outer member <NUM>, inner member <NUM>, and locking member <NUM> can each have a substantially cylindrical configuration. This configuration can advantageously simplify manufacturing, for example, by allowing much simpler processing and machining procedures (such as Swiss-type and milling procedures) to be used. Furthermore, the telescoping movement of the members <NUM>, <NUM>, <NUM> relative to one another advantageously provides continuous valve expansion wherein the expansion and locking mechanism <NUM> can be easily maneuvered between the locked and unlocked configurations.

As shown in <FIG>, the proximal end portion of each member <NUM>, <NUM>, <NUM> can comprise an engagement portion configured to releasably couple a corresponding actuator of a delivery apparatus, as described in more detail below. In the illustrated embodiment, the proximal end portion <NUM> of the outer member <NUM> comprises an outer engagement portion configured as a threaded portion <NUM>, the proximal end portion <NUM> of the second member <NUM> comprises an engagement portion <NUM> including one or more cutouts, and a proximal end portion <NUM> of the locking member <NUM> can comprise an engagement portion configured as an inner bore including, for example, a threaded portion <NUM> (<FIG>).

During delivery of the prosthetic valve <NUM>, the expansion and locking mechanism <NUM> can be releasably coupled to a delivery apparatus, such as delivery apparatus <NUM> (<FIG>) comprising one or more actuator assemblies <NUM>. For example, as shown in <FIG>, an actuator assembly <NUM> can couple a respective expansion and locking mechanism <NUM> in the following exemplary manner.

Referring now to <FIG>, the outer threaded portion <NUM> (<FIG>) of the outer member <NUM> can be configured to couple a correspondingly threaded portion <NUM> of a first actuator <NUM> of the delivery apparatus. A proximal end portion <NUM> (<FIG>) of the second member <NUM> can comprise an engagement portion <NUM> including one or more cutouts and configured to releasably couple a second actuator <NUM> extending coaxially through the first actuator <NUM>. As best shown in <FIG>, the second actuator <NUM> can comprise one or more flexible elongated elements <NUM> including protrusions <NUM> configured to releasably couple the engagement portion <NUM> of the second member <NUM>. The elongated elements <NUM> can be disposed, for example, at the distal end of the second actuator <NUM>. The elongated elements can be formed by, for example, laser cutting, and the protrusions <NUM> can have a shape corresponding to the shape of the cutouts.

Referring to <FIG>, the elongated elements <NUM> can be configured to bias radially outward, for example, by shape setting the elongated elements <NUM>. The second actuator <NUM> can comprise a cutout <NUM> configured to allow the elongated elements <NUM> to flex outward. In order to couple the expansion and locking mechanism <NUM> to the delivery apparatus, the second actuator <NUM> can be positioned such that the protrusions <NUM> are disposed adjacent the cutouts of the engagement portion <NUM>, as shown in <FIG>. As the first actuator <NUM> is advanced (e.g., distally) over the second actuator to couple the outer member <NUM>, the elongated elements <NUM> are radially compressed until they sit within the cutouts, as shown in <FIG>, coupling the second actuator <NUM> to the second member <NUM>. The first actuator <NUM> can continue to be advanced until the threaded portion <NUM> of the first actuator <NUM> engages the threaded portion <NUM> of the outer member <NUM>, as shown in <FIG>.

Referring again to <FIG>, as mentioned previously, a proximal end portion <NUM> of the locking member <NUM> can comprise an engagement portion configured as an inner bore including a threaded portion <NUM>. A third actuator <NUM> of the delivery apparatus can extend coaxially through the first and second actuators <NUM>, <NUM> and can have a correspondingly threaded portion <NUM> configured to releasably couple the threaded portion <NUM> of the locking member <NUM>.

The first, second, and third actuators <NUM>, <NUM> and <NUM> can form an actuator assembly <NUM>. Each actuator assembly <NUM> can be releasably coupled to and control operation of a respective expansion and locking mechanism <NUM>. Each actuator assembly <NUM> can be coupled to a handle <NUM> of the delivery apparatus and the components of the actuator assembly (e.g., actuators <NUM>, <NUM>, <NUM>) can be axially movable relative to one another to cause corresponding axial movement of the first, second, and locking members <NUM>, <NUM>, <NUM> relative to one another, as further described below.

In other embodiments, the engagement portions can have other configurations that permit the first, second, and locking members <NUM>, <NUM>, <NUM> to be releasably coupled to the delivery apparatus. For example, in some embodiments, the engagement portion of the locking member <NUM> can comprise a magnetic material and the third actuator can comprise a corresponding magnet that can extend into the engagement portion.

A prosthetic valve <NUM> including one or more expansion and locking mechanisms <NUM> can be expanded in the following exemplary manner. Generally, the prosthetic valve <NUM> is placed in a radially compressed state and releasably coupled to a distal end portion of a delivery apparatus (such as delivery apparatus <NUM> shown in <FIG>), as described above, and advanced through the vasculature of a patient to a selected implantation site (e.g., the native aortic annulus). The prosthetic valve <NUM> can then be deployed at the implantation site and can be expanded and locked in the expanded configuration using the expansion and locking mechanisms <NUM>. Once a selected diameter of the prosthetic valve <NUM> is reached, the delivery apparatus can be uncoupled from the expansion and locking mechanisms <NUM> and removed from the patient's body.

Referring again to <FIG>, to deploy the prosthetic valve, the physician can actuate the delivery apparatus, which can actuate the one or more expansion and locking mechanisms <NUM>. The second member <NUM> can move proximally (as shown by arrow <NUM>) and/or the first member <NUM> can move distally (as shown by arrow <NUM>) to decrease the distance between the attachment locations, causing the frame <NUM> to foreshorten axially and expand radially until a selected diameter is achieved.

As the frame <NUM> expands, the radially inner and radially outer struts 304a, 304b can pivot relative to one another, thereby pivoting the first and second flanges 322a, 322b relative to one another to define the gap G between them (see <FIG>). Once the gap G is large enough to accommodate the engagement member <NUM>, the physician can use the delivery apparatus to advance the locking member <NUM> distally until the engagement member <NUM> is disposed within the gap G between the first and second flanges 322a, 322b, as shown in <FIG>.

The engagement of the engagement member <NUM> with the first and second flanges 322a, 322b retains the frame <NUM> in a locked configuration, where the frame can be further radially expanded but cannot be radially collapsed. In other words, the engagement of the engagement member <NUM>, with the flanges <NUM> permits pivoting movement of the struts <NUM> relative to each other in a first direction to expand the frame <NUM> and resists pivoting movement of the struts <NUM> relative to each other to resist radial compression of the frame <NUM> from forces exerted on the frame by the surrounding anatomy.

The frictional engagement between the engagement member <NUM> and the flanges <NUM> prevents the engagement member <NUM> from being displaced relative to the flanges <NUM>. For example, once the prosthetic valve has been implanted within a selected implantation site within a patient, the patient's native anatomy (e.g., the native aortic annulus) may exert radial forces against the prosthetic valve <NUM> that would tend to compress the frame <NUM>. However, the frictional engagement of the engagement member <NUM> with the flanges <NUM> prevents such forces from displacing the engagement member and compressing the frame <NUM>.

If repositioning or recapture and removal of the prosthetic valve <NUM> is desired, the prosthetic valve can be unlocked by retracting the locking member <NUM> proximally until the engagement member <NUM> is no longer disposed between the first and second flanges 322a, 322b, allowing the struts <NUM> to pivot freely relative to one another in either direction. In order to retract the locking member <NUM> a proximally-directed force must be applied to the locking member <NUM> that is greater than the force of the frictional engagement between the flanges <NUM> and the engagement member <NUM>.

Referring now to <FIG>, in some embodiments, in lieu of second member <NUM> the expansion and locking mechanism <NUM> can comprise second member <NUM>. Second member <NUM> can be similar to second member <NUM> except that second member <NUM> can be configured to bias the locking member <NUM> in a distal direction, as described in more detail below.

Referring to <FIG>, the second member <NUM> can have a first end portion <NUM> including a fastener <NUM> similar to fastener <NUM> described above, a second end portion <NUM>, and an inner lumen or bore <NUM>. The second member <NUM> can comprise a biasing portion <NUM> disposed between the first and second end portions <NUM>, <NUM>. The biasing portion <NUM> can be movable between a compressed configuration and an extended configuration and can be configured to bias the second end portion <NUM> in a first direction, for example, toward the inflow end portion <NUM> of the prosthetic valve <NUM>.

In the illustrated embodiment, the biasing portion <NUM> is configured as a spring <NUM> (such as a compression spring). In some embodiments, the spring <NUM> can be formed integrally with the second member <NUM>, for example, by laser cutting a central portion of the second member <NUM> into a helical shape. In other embodiments, the spring <NUM> can be formed as a separate component and can be coupled to the first and second end portions <NUM>, <NUM> of the second member <NUM>. In other embodiments, the biasing portion <NUM> can have any of various configurations. For example, the biasing portion <NUM> can comprise a spring washer, a compressible polymeric sleeve, etc..

As shown in <FIG>, when the expansion and locking mechanism <NUM> comprising second member <NUM> is assembled, the locking member <NUM> extends at least partially through the second member <NUM>. The biasing portion <NUM> can be sized such that when the prosthetic valve <NUM> is in the compressed configuration, the biasing portion <NUM> is axially compressed or loaded. In the loaded state, a distal edge <NUM> of the second member <NUM> applies a proximally-directed force to the shoulder <NUM> of the locking member <NUM>.

When the prosthetic valve <NUM> is in the compressed configuration, as shown in <FIG>, the biasing portion <NUM> biases the locking member <NUM> distally toward the inflow end <NUM> such that the engagement member <NUM> abuts the radially extending portion 326a of the first flange 322a. As the frame <NUM> expands, the inner and outer struts 304a, 304b pivot relative to one another, thereby pivoting the flanges <NUM> relative to one another to define the gap G between them. The biasing portion <NUM> continues to bias the locking member <NUM>, and therefore the engagement portion <NUM>, distally against the first and/or second flanges 322a, 322b until the gap G is large enough to accommodate the engagement member <NUM>, at which point the biasing portion <NUM> will bias the engagement member <NUM> into the gap G, as shown in <FIG>.

If repositioning or recapture and removal of the prosthetic valve <NUM> is desired, the prosthetic valve can be unlocked by retracting the locking member <NUM> proximally until the engagement member <NUM> is no longer disposed between the first and second flanges 322a, 322b, thereby allowing the struts <NUM> to pivot freely relative to one another in either direction. In order to retract the locking member <NUM> a proximally-directed force must be applied to the locking member <NUM> that is greater than the force of the frictional engagement between the flanges <NUM> and the engagement member <NUM> and the force of the biasing portion <NUM>.

In some embodiments, the biasing portion <NUM> can be sized such that when the prosthetic valve <NUM> is in the expanded configuration (<FIG>), the biasing portion <NUM> is in the uncompressed or unloaded configuration such that the biasing portion no longer applies a biasing force. In other embodiments, the biasing portion <NUM> can be sized such that when the prosthetic valve <NUM> is in the expanded configuration, the biasing portion <NUM> continues to apply a biasing force in the distal direction to help retain the engagement member <NUM> between the flanges <NUM>.

<FIG> illustrates a delivery apparatus <NUM>, according to one embodiment, adapted to deliver a prosthetic heart valve <NUM>, such as the illustrated prosthetic heart valve <NUM>, <NUM>, or <NUM> described above. The prosthetic valve <NUM> can be releasably coupled to the delivery apparatus <NUM>. It should be understood that the delivery apparatus <NUM> and other delivery apparatuses disclosed herein can be used to implant prosthetic devices other than prosthetic valves, such as stents or grafts.

The delivery apparatus <NUM> in the illustrated embodiment generally includes a handle <NUM>, a first elongated shaft <NUM> (which comprises an outer shaft in the illustrated embodiment) extending distally from the handle <NUM>, at least one actuator assembly <NUM> extending distally through the outer shaft <NUM>. The at least one actuator assembly <NUM> can be configured to radially expand and/or radially collapse the prosthetic valve <NUM> when actuated.

Though the illustrated embodiment shows two actuator assemblies <NUM> for purposes of illustration, it should be understood that one actuator <NUM> can be provided for each actuator (e.g., each expansion and locking mechanism) on the prosthetic valve. For example, three actuator assemblies <NUM> can be provided for a prosthetic valve having three actuators. In other embodiments, a greater or fewer number of actuator assemblies can be present.

In some embodiments, a distal end portion <NUM> of the shaft <NUM> can be sized to house the prosthetic valve in its radially compressed, delivery state during delivery of the prosthetic valve through the patient's vasculature. In this manner, the distal end portion <NUM> functions as a delivery sheath or capsule for the prosthetic valve during delivery,.

The actuator assemblies <NUM> can be releasably coupled to the prosthetic valve <NUM>. For example, in the illustrated embodiment, each actuator assembly <NUM> can be coupled to a respective actuator (e.g., expansion and locking mechanism <NUM>) of the prosthetic valve <NUM>. Each actuator assembly <NUM> can comprise a first actuator (e.g., first actuator <NUM>, which can be a support tube), a second actuator (e.g., second actuator <NUM>), and a third actuator (e.g., third actuator <NUM>, which can be a locking tool for operating locking member <NUM>). When actuated, the actuator assembly can transmit pushing and/or pulling forces to portions of the prosthetic valve to radially expand and collapse the prosthetic valve as previously described. The actuator assemblies <NUM> can be at least partially disposed radially within, and extend axially through, one or more lumens of the outer shaft <NUM>. For example, the actuator assemblies <NUM> can extend through a central lumen of the shaft <NUM> or through separate respective lumens formed in the shaft <NUM>.

The handle <NUM> of the delivery apparatus <NUM> can include one or more control mechanisms (e.g., knobs or other actuating mechanisms) for controlling different components of the delivery apparatus <NUM> in order to expand and/or deploy the prosthetic valve <NUM>. For example, in the illustrated embodiment the handle <NUM> comprises first, second, third and fourth knobs <NUM>, <NUM>, <NUM>, and <NUM>.

The first knob <NUM> can be a rotatable knob configured to produce axial movement of the outer shaft <NUM> relative to the prosthetic valve <NUM> in the distal and/or proximal directions in order to deploy the prosthetic valve from the delivery sheath <NUM> once the prosthetic valve has been advanced to a location at or adjacent the desired implantation location with the patient's body. For example, rotation of the first knob <NUM> in a first direction (e.g., clockwise) can retract the sheath <NUM> proximally relative to the prosthetic valve <NUM> and rotation of the first knob <NUM> in a second direction (e.g., counter-clockwise) can advance the sheath <NUM> distally. In other embodiments, the first knob <NUM> can be actuated by sliding or moving the knob <NUM> axially, such as pulling and/or pushing the knob. In other embodiments, actuation of the first knob <NUM> (rotation or sliding movement of the knob <NUM>) can produce axial movement of the actuator assemblies <NUM> (and therefore the prosthetic valve <NUM>) relative to the delivery sheath <NUM> to advance the prosthetic valve distally from the sheath <NUM>.

The second knob <NUM> can be a rotatable knob configured to produce radial expansion and/or contraction of the prosthetic valve <NUM>. For example, rotation of the second knob <NUM> can move the first actuator (e.g., actuator <NUM>) and the second actuator (e.g., actuator <NUM>) relative to one another (for example, to cause corresponding movement of the outer and inner members <NUM>, <NUM> relative to one another). Rotation of the second knob <NUM> in a first direction (e.g., clockwise) can radially expand the prosthetic valve <NUM> and rotation of the second knob <NUM> in a second direction (e.g., counter-clockwise) can radially collapse the prosthetic valve <NUM>. In other embodiments, the second knob <NUM> can be actuated by sliding or moving the knob <NUM> axially, such as pulling and/or pushing the knob. In other embodiments, the first and second actuators can each be coupled to a respective knob such that they can be actuated independently from one another.

The third knob <NUM> can be a rotatable knob configured to retain the prosthetic heart valve <NUM> in its expanded configuration. For example, the third knob <NUM> can be operatively connected to a third actuator (e.g., third actuator <NUM>) that can be releasably coupled to a locking member (e.g., locking member <NUM>). Rotation of the third knob in a first direction (e.g., clockwise) can advance the third actuator distally to, for example, advance the engagement member <NUM> of locking member <NUM> such that it engages the flanges <NUM> to resist radial compression of the frame of the prosthetic valve, as described above. Rotation of the knob <NUM> in the opposite direction (e.g., counterclockwise) can retract the third actuator proximally to unlock the frame and allow for repositioning or recapture and removal. In other embodiments, the third knob <NUM> can be actuated by sliding or moving the third knob <NUM> axially, such as pulling and/or pushing the knob.

As shown in the illustrated embodiment, the handle <NUM> can include a fourth knob <NUM> (e.g., a rotatable knob) operatively connected to a proximal end portion of one or more of the actuators <NUM>, <NUM>, <NUM>. The fourth knob <NUM> can be configured to, upon rotation of the knob, to decouple each of the one or more actuators from, for example, a respective component of the expansion and locking mechanism. For example, the fourth knob <NUM> can be operable to rotate the first actuator <NUM> in a direction that causes a threaded distal end portion of the first actuator to decouple from the threaded portion <NUM> of the outer member <NUM> of the expansion and locking mechanism <NUM>. Similarly, the fourth knob <NUM> (or an additional knob) can be operable to rotate the third actuator <NUM> in a direction that causes a threaded distal end portion of the third actuator to decouple from the threaded portion <NUM> of the locking member <NUM> of the expansion and locking mechanism <NUM>. Once the actuators have been decoupled from the prosthetic valve, the delivery apparatus <NUM> can be removed from the patient.

It should be understood that the disclosed embodiments can be adapted to deliver and implant prosthetic devices in any of the native annuluses of the heart (e.g., the pulmonary, mitral, and tricuspid annuluses), and can be used with any of various delivery approaches (e.g., retrograde, antegrade, transseptal, transventricular, transatrial, etc.).

For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.

All features described herein are independent of one another and, except where structurally impossible, can be used in combination with any other feature described herein. For example, expansion and locking mechanisms <NUM> as shown in <FIG> or <FIG> can be used in combination with prosthetic valve <NUM> or with prosthetic valve <NUM>.

As used in this application and in the claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Additionally, the term "includes" means "comprises. " Further, the term "coupled" generally means physically, mechanically, chemically, magnetically, and/or electrically coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language.

As used herein, the term "proximal" refers to a position, direction, or portion of a device that is closer to the user and further away from the implantation site. As used herein, the term "distal" refers to a position, direction, or portion of a device that is further away from the user and closer to the implantation site. Thus, for example, proximal motion of a device is motion of the device away from the implantation site and toward the user (e.g., out of the patient's body), while distal motion of the device is motion of the device away from the user and toward the implantation site (e.g., into the patient's body). The terms "longitudinal" and "axial" refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

Claim 1:
An implantable prosthetic device, comprising:
a frame (<NUM>, <NUM>) movable between a radially compressed and a radially expanded configuration, the frame (<NUM>, <NUM>) comprising an inflow end portion (<NUM>) and an outflow end portion (<NUM>), the frame (<NUM>, <NUM>) comprising a plurality of struts (<NUM>);
at least one expansion and locking mechanism (<NUM>) comprising:
a first member (<NUM>) coupled to the frame at a first location,
a second member (<NUM>) coupled to the frame (<NUM>, <NUM>) at a second location spaced apart from the first location, the second member (<NUM>) extending at least partially into the first member (<NUM>),
a third member (<NUM>) having a first end portion (<NUM>) and a second end portion (<NUM>), the first end portion (<NUM>) extending at least partially into the first member (<NUM>) and the second end portion (<NUM>) comprising an engagement portion (<NUM>);
wherein the plurality of struts (<NUM>) includes a first strut (304a) and a second strut (304b) pivotably coupled to one another to form an apex, the first strut (304a) comprising a first flange (322a) and the second strut comprising a second flange (322b); and
wherein, when the frame (<NUM>, <NUM>) is in the expanded configuration, advancement of the third member (<NUM>) in a distal direction positions the engagement portion (<NUM>) between the first and second flanges (322a, 322b) such that the first and second flanges (322a, 322b) engage the engagement member (<NUM>) to resist pivoting of the first and second struts (304a, 304b) relative to one another in a first direction to resist radial compression of the frame (<NUM>, <NUM>).