Patent Description:
The present disclosure relates to prosthetic heart valves, and to methods and assemblies for forming commissures associated with leaflets of such prosthetic heart valves.

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 device and advanced through the patient's vasculature (e.g., through a femoral artery and the aorta) until the prosthetic valve reaches the implantation site in the heart. The prosthetic 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 valve, or by deploying the prosthetic valve from a sheath of the delivery device so that the prosthetic valve can self-expand to its functional size.

Prosthetic valves that rely on a mechanical actuator for expansion can be referred to as "mechanically expandable" prosthetic heart valves. The actuator typically takes the form of pull cables, sutures, wires and/or shafts that are configured to transmit expansion forces from a handle of the delivery apparatus to the prosthetic valve. Most expandable, transcatheter heart valves comprise a cylindrical metal frame or stent and prosthetic leaflets mounted inside the frame. The leaflets may be attached to the frame at commissure tab of the leaflets. However, in some configurations, forces experienced during operation of the prosthetic valve and/or other conditions may be concentrated at the commissure tabs, which may compromise the structure of the leaflets and/or cause the leaflets to detach from the frame. Furthermore, the attachment of the commissure tabs to the frame in such configurations may require delicate assembly skills to ensure proper attachment and reduce damage to the leaflets.

<CIT> describes a prosthetic heart valve including a radially collapsible and expandable annular frame having a plurality of struts defining openings. The prosthetic heart valve can further include a plurality of leaflets that regulate the flow of blood through the frame. A method for forming a commissure from two leaflets is also described. Each leaflet comprises a lower edge portion terminating at lower tabs and upper tabs spaced from the lower tabs by gaps. Each upper tab includes a lower tab portion, an upper tab portion extending from the lower tab portion and a side tab portion extending laterally inwardly from the upper tab portion. A commissure attachment member may be placed against the outer surface of the lower tab portion and secured to the upper tab with stitching that extends through the upper tab portion, a reinforcement member, the side tab portion, the lower tab portion and the commissure attachment member.

<CIT> describes a prosthetic heart valve for an endoprosthesis used in the treatment of a stenotic cardiac valve and/or a cardiac valve insufficiency. The prosthetic heart valve comprises of a plurality of leaflets and a leaflet support portion, consisting of biological and/or synthetic material for mounting of the prosthetic heart valve to a stent, and a bendable transition area which forms a junction between the leaflets and the leaflet support portion, the transition area progressing essentially in a U-shaped manner similar to a cusp shape of a natural aortic or pulmonary heart valve for reducing tissue stresses during opening and closing motion of the leaflets.

Accordingly, a need exists for improved prosthetic heart valve leaflet assemblies and methods for assembling the leaflet assemblies to a frame of the prosthetic heart valve.

Described herein are methods for assembling a prosthetic heart valve, methods of assembling a commissure of a prosthetic valve, and a prosthetic heart valve including a plurality of commissures. In some examples, the commissures may be formed by coupling a pair of adjacent commissure tabs of adjacent leaflets of the prosthetic heart valve. The commissures may include a support strip, optionally folded over an inner reinforcing element, with a main body and a tab portion extending from and folded over a portion of the main body. The support strip may include alignment indicators for alignment of the tab portion over the main body, and alignment markings for locations of sutures that pass through the support strip and other elements of the commissure to form the commissure and/or secure the commissure to a support structure of the prosthetic heart valve.

A first aspect of the present invention provides a method of assembling a prosthetic heart valve comprising a plurality of leaflets including: forming a plurality of commissures with the plurality of leaflets, wherein each commissure is formed by pairing a first commissure tab of a first leaflet with an adjacent, second commissure tab of a second leaflet, coupling a main body of a support strip to the first and second commissure tabs via primary sutures, folding a tab portion of the support strip over a central region of the main body, and coupling the tab portion of the support strip to the central region of the main body via secondary sutures, and, for each commissure, securing the commissure to a respective support portion of a frame of the prosthetic heart valve. Coupling the main body of the support strip to the first and second commissure tabs includes stitching the primary sutures through, in order or in reverse order: a first side of the main body of the support strip, the first commissure tab, the second commissure tab, and a second side of the main body of the support strip. The main body of the support strip and the tab portion of the support strip are positioned between the commissure tabs and the respective support portion of the frame of the prosthetic heart valve.

A second aspect of the present invention provides a prosthetic heart valve including: an annular frame comprising a plurality of commissure support portions, and a plurality of leaflets, each leaflet having a commissure tab that is coupled to an adjacent commissure tab of another leaflet via a support strip to form a commissure of an associated commissure tab pair, and, for each commissure tab pair: the support strip includes a main body and a tab portion extending from and folded over a central region of the main body, a primary suture passes through, in order or in reverse order, a first side of the main body, a first commissure tab of the commissure tab pair, a second commissure tab of the commissure tab pair, and a second side of the main body, and a secondary suture passes through the tab portion and the main body to couple the tab portion to the central region of the main body, and each commissure is secured to a corresponding commissure support portion of the plurality of commissure support portions. The main body of the support strip and the tab portion of the support strip are positioned between the commissure tabs and the respective support portion of the frame of the prosthetic heart valve.

Also disclosed is a method of assembling a commissure for a leaflet pair of a prosthetic valve which can include: attaching a main body of a support strip to adjacent ends of a first commissure tab of a first leaflet of the leaflet pair and a second commissure tab of a second leaflet of the leaflet pair by stitching primary sutures through edge alignment markings of the support strip, folding and aligning a tab portion of the support strip over the main body of the support strip in accordance with one or more strip alignment indicators, attaching the tab portion of the support strip to the main body of the support strip by stitching secondary sutures through central alignment markings of the support strip, and coupling end portions of the main body of the support strip to one another around a support portion of a frame of the prosthetic valve via tertiary sutures to secure the commissure to the support portion of the frame.

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. The technologies from any example can be combined with the technologies described in any one or more of the other examples. In view of the many possible embodiments to which the principles of the disclosed technology may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the disclosed technology.

As used herein, with reference to the prosthetic heart valve and the transcatheter delivery system, "proximal" refers to a position, direction, or portion of a component that is closer to the user and a handle of the delivery system that is outside the patient, while "distal" refers to a position, direction, or portion of a component that is further away from the user and the handle and closer to the implantation site. The terms "longitudinal" and "axial" refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

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 terms "coupled" and "connected" generally mean electrically, electromagnetically, and/or physically (e.g., mechanically or chemically) coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language.

Directions and other relative references (e.g., inner, outer, upper, lower, etc.) may be used to facilitate discussion of the drawings and principles herein, but are not intended to be limiting. For example, certain terms may be used such as "inside," "outside,", "top," "down," "interior," "exterior," and the like. Such terms are used, where applicable, to provide some clarity of description when dealing with relative relationships, particularly with respect to the illustrated embodiments. Such terms are not, however, intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an "upper" part can become a "lower" part simply by turning the object over. Nevertheless, it is still the same part and the object remains the same. As used herein, "and/or" means "and" or "or," as well as "and" and "or.

Described herein are examples of prosthetic heart valves, commissures for prosthetic valves, and methods for assembling commissures of prosthetic valves. The prosthetic heart valves include a frame and a plurality of leaflets attached to the frame via commissures formed by joining pairs of adjacent ends (e.g., commissure tabs) of the leaflets. The formation of the commissures includes attaching a support strip (including a main portion and a tab portion folded over a central region of the main portion), which is optionally folded over one or more reinforcing members (e.g., in alignment according to one or more alignment indicators on the support strip), to commissure tabs of the leaflets. Opposing ends of the support strip may be coupled together via a primary suture(s) passing through the opposing ends of the support strip (e.g., in locations corresponding to alignment markers forming suture lines on the support strip), the commissure tabs, and optionally the reinforcing members. The folded-over tab portion of the support strip is secured to the main portion of the support strip via one or more secondary sutures each of which may pass through the tab portion of the support strip (e.g., in locations corresponding to alignment markers forming suture lines on the support strip), a respective commissure tab, a respective side of the main portion of the support strip, and optionally a respective reinforcing member. Opposing ends of the primary suture(s), secondary sutures, and/or an additional suture(s) (e.g., tertiary sutures) may be wrapped around a corresponding commissure support portion of the frame of the prosthetic valve to secure the commissure to the frame.

In this way, forces experienced by the leaflets during radial expansion and compression of the frame and/or as the leaflets open and closed during operation of the prosthetic valve may be at least partially absorbed by the support strip, reducing the stresses exerted on the leaflets. As the support strip may be made of more robust material than the leaflets, the overall strength of the commissure may be increased relative to other configurations. Folding a portion of the support strip over itself (e.g., folding a tab portion of the support strip over a central region of a main body of the support strip) provides additional reinforcing strength for the commissure by providing a further deflection of stresses away from the potentially relatively delicate material of the leaflets. The use of alignment indicators (e.g., notches, markings, apertures, etc.) and/or alignment markings forming suture lines provides additional guidance during assembly of the commissure, reducing assembly difficulty and ensuring proper alignment of elements to maximize reinforcement strength.

<FIG> shows an exemplary prosthetic heart valve <NUM>, according to one embodiment. The prosthetic heart valve <NUM> can be radially compressible and expandable between a radially compressed configuration for delivery into a patient and a radially expanded configuration. In particular embodiments, the prosthetic heart valve <NUM> can be implanted within the native aortic valve, although it also can be implanted at other locations in the heart, including within the native mitral valve, the native pulmonary valve, and the native tricuspid valve. The prosthetic heart valve <NUM> includes an annular stent or frame <NUM> having a first end <NUM> and a second end <NUM>.

In the depicted embodiment, the first end <NUM> is an inflow end and the second end <NUM> is an outflow end. The outflow end <NUM> can be coupled to a delivery apparatus for delivering and implanting the prosthetic heart valve within the native aortic valve is a transfemoral, retrograde delivery approach. Thus, in the delivery configuration of the prosthetic heart valve, the outflow end <NUM> is the proximal-most end of the prosthetic valve. In other embodiments, the inflow end <NUM> can be coupled to the delivery apparatus, depending on the particular native valve being replaced and the delivery technique that is used (e.g., trans-septal, transapical, etc.). For example, the inflow end <NUM> can be coupled to the delivery apparatus (and therefore is the proximal-most end of the prosthetic heart valve in the delivery configuration) when delivering the prosthetic heart valve to the native mitral valve via a trans-septal delivery approach.

The frame <NUM> 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. Referring again to <FIG>, as shown, the frame <NUM> can include a plurality of interconnected struts <NUM> arranged in a lattice-type pattern. The struts <NUM> are shown as positioned diagonally, or offset at an angle relative to, and radially offset from, a longitudinal axis of the prosthetic heart valve <NUM> when the prosthetic heart 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 of the prosthetic heart valve <NUM>.

In the illustrated embodiment, the struts <NUM> are pivotably coupled to one another at one or more pivot joints along the length of each strut. For example, in the illustrated configuration, each of the struts <NUM> can be formed with apertures 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 or pivot members, such as rivets or pins <NUM> that extend through the apertures. 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 heart valve <NUM>.

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. In other embodiments, the struts <NUM> are not coupled to each other with respective hinges but are otherwise pivotable or bendable relative to each other to permit radial expansion and contraction of the frame <NUM>. For example, the frame <NUM> can be formed (e.g., via laser cutting, electroforming or physical vapor deposition) from a single piece of material (e.g., a metal tube). Further details regarding the construction of the frame and the prosthetic heart valve are described in <CIT>, <CIT>, and <CIT>.

The prosthetic heart valve <NUM> can also include a valvular structure <NUM> which is coupled to the frame <NUM> and configured to regulate the flow of blood through the prosthetic heart valve <NUM> from the inflow end <NUM> to the outflow end <NUM>. The prosthetic heart valve <NUM> can further include a plurality of actuators <NUM> mounted to and equally spaced around the inner surface of the frame <NUM>. The actuators are configured to apply expansion and compression to the frame for radially expanding and compressing the prosthetic valve.

In the illustrated embodiment, the actuators <NUM> are linear actuators, each of which comprises an inner member, or piston, <NUM> and an outer member, or cylinder, <NUM>. The inner member <NUM> is pivotably coupled to a junction of the frame, such as at the first end <NUM>, while the outer member <NUM> is pivotably coupled to another junction of the frame closer to the second end <NUM>. Moving the inner member <NUM> proximally relative to the outer member <NUM> and/or moving the outer member <NUM> distally relative to the inner member <NUM> is effective to radially expand the prosthetic valve. Conversely, moving the inner member <NUM> distally relative to the outer member <NUM> and/or moving the outer member <NUM> proximally relative to the inner member <NUM> is effective to radially compress the prosthetic valve. The actuators <NUM> can include locking mechanisms that are configured to retain the prosthetic valve in an expanded state inside the patient's body.

In some embodiments, each of the actuators <NUM> can be configured to form a releasable connection with one or more respective actuators of a delivery apparatus of a transcatheter delivery system. The actuators of the delivery apparatus can transmit forces from a handle of the delivery apparatus to the actuators <NUM> for expanding or compressing the prosthetic valve. Further details of the actuators, locking mechanisms and delivery apparatuses for actuating the actuators can be found in <CIT>, <CIT> and <CIT>, PCT Application No. <CIT>, PCT Application No. <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.

In some embodiments, each of the actuators <NUM> can be used to support a respective commissure <NUM> (described below). As such, the actuators <NUM> can include commissure support portions for supporting and attaching commissures <NUM> of the valvular structure <NUM> to the frame <NUM>, as described further herein.

The valvular structure <NUM> can include, for example, a leaflet assembly comprising one or more leaflets <NUM> (three leaflets <NUM> in the illustrated embodiment) made of a flexible material. The leaflets <NUM> of the leaflet assembly 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> are arranged to form commissures <NUM>, which can be, for example, mounted to commissure support portions of respective actuators <NUM>. Further details regarding transcatheter prosthetic heart valves, including the manner in which the valvular structure can be coupled to the frame <NUM> of the prosthetic heart valve <NUM>, can be found, for example, in <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>, and <CIT>.

In some embodiments, as shown in <FIG>, the commissures <NUM> can be mounted (e.g., sutured) directly to commissure support portions of the actuators <NUM> of the frame <NUM> via commissure attachments <NUM>, which can be strips of fabric. As one example, each commissure attachment <NUM> may be wrapped around a corresponding actuator <NUM> and a pair of adjacent commissure tabs of adjacent leaflets and secured to the commissure tabs and the actuator via one or more stitches extending through the commissure attachment and the pair of the commissure tabs. In other embodiments, the commissures <NUM> can be mounted to support struts or posts of the frame that are separate from the actuators <NUM>.

The prosthetic heart valve <NUM> can also include one or more skirts or sealing members. For example, as shown in <FIG>, the prosthetic heart valve <NUM> can include an inner skirt <NUM> mounted on the inner surface of the frame <NUM>. As shown in <FIG>, the inner skirt <NUM> is a circumferential inner skirt that spans an entire circumference of the inner surface of the frame <NUM>. The inner skirt <NUM> can function as a sealing member to prevent or decrease paravalvular leakage (e.g., when the valve is placed at the implantation site) and as an attachment surface to anchor the leaflets <NUM> to the frame <NUM>.

For example, as shown, a cusp edge portion <NUM> of each leaflet <NUM> (the inflow edge portion) can be secured to the inner skirt <NUM> with stitching <NUM> (referred to as a "scallop line"). The upper and lower edge portions of the inner skirt <NUM> can be secured to the frame with suture loops <NUM> that extending through the inner skirt and around adjacent struts <NUM> of the frame. In this manner, the cusp edge portions of the leaflets are supported by the inner skirt <NUM> and the commissures are supported by actuators <NUM>.

The prosthetic heart valve <NUM> can also include an outer skirt mounted on the outer surface of the frame <NUM> (not shown in <FIG>). The outer skirt 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 (e.g., PET) or natural tissue (e.g., pericardial tissue). The inner and outer skirts can be mounted to the frame using sutures, an adhesive, welding, and/or other means for attaching the skirts to the frame.

<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>, described above with respect to <FIG>. 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 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 of the prosthetic valve <NUM>. Each actuator assembly <NUM> can comprise a support tube, an actuator member, and a locking tool. 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, and third knobs <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 actuator member and the support tube axially 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.

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 proximal end portion of the locking tool of each actuator assembly <NUM>. Rotation of the third knob in a first direction (e.g., clockwise) can rotate each locking tool to advance the locking nuts to their distal positions 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 rotate each locking tool in the opposite direction to decouple each locking tool from the prosthetic valve <NUM>. 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.

Although not shown, the handle <NUM> can include a fourth rotatable knob operative connected to a proximal end portion of each actuator member. The fourth knob can be configured to rotate each actuator member, upon rotation of the knob, to unscrew each actuator member from the proximal portion of a respective actuator. As described above, once the locking tools and the actuator members are uncoupled from the prosthetic valve <NUM>, they can be removed from the patient.

<FIG> show example commissure tab assemblies and attachments of commissure tab assemblies to a commissure post or other support structure of a frame of a prosthetic valve. <FIG> show an example commissure tab assembly from two different view angles and <FIG> show example cross-sectional views of the commissure tab assembly in two different states (e.g., prior to wrapping the commissure around a support structure of the frame and after wrapping the commissure at least partially around a support structure of the frame, respectively). <FIG> shows a schematic representation of a commissure tab assembly including elements corresponding to those of <FIG>.

A commissure tab assembly may be pre-assembled prior to attachment thereof to the frame by performing a pre-assembly process. The pre-assembly process includes, in one example, extending a primary suture <NUM> along a first suture line having a plurality of in-and-out stitches extending through, in order (or in the reverse order, e.g., starting from the last-listed element and extending through the following list of elements, in reverse, to the first-listed element), a first side of a support strip (e.g., a flexible cloth/fabric) <NUM>, optionally a first reinforcing element 240a (for example configurations that include reinforcing members/elements), a first commissure tab 220a, a second commissure tab 220b (where commissure tabs 220a and 220b are two commissure tabs of adjacent leaflets, e.g., leaflets 221a and 221b), optionally a second reinforcing element 240b (for example configurations that include reinforcing members), and along (e.g., through apertures/markings of) a second suture line on the second side of the support strip <NUM>. As used herein, the term "suture line" can also be referred to as a "stitch line. " The second side of the support is opposite the first side relative to a center of the support strip (e.g., a centerline that divides a width/longest dimension of the strip in half).

<FIG> shows another example of a primary suture <NUM> forming stitches passing from primary suture lines 452a (e.g., through edge alignment markings on a first side of a support strip <NUM>) to primary suture lines 452b (e.g., through edge alignment markings on a second side of the support strip <NUM> opposite of the first side), where the suture <NUM> passes through one or more layers of the first side of the support strip <NUM>, reinforcing elements 440a and 440b, commissure tabs 420a and 420b (of leaflets 421a and 421b, respectively), and one or more layers of the second side of the support strip <NUM>.

Returning to <FIG>, the support strip <NUM> may be a strip of any suitable material (e.g., fabric), which may include material that is stronger (e.g., more resilient to tearing and/or deforming) than a material used for forming the leaflets and/or the commissure tab portions of the leaflets of the prosthetic valve. In one example, the support strip <NUM> is a polyethylene terephthalate (PET) fabric, although various other suitable biocompatible fabrics can be used.

In the presently claimed invention, the support strip <NUM> includes a main body and a tab portion, as will be described in more detail below with respect to the example support strips illustrated in <FIG>, and the main body portion of the support strip may be longer in one dimension than another (e.g., having a width/length that is greater than a height of the strip). The support strip <NUM> may be continuous (e.g., with no gaps and/or having a substantially uniform distribution of the material forming the support strip, other than optional apertures forming the suture lines described herein) and may be relatively thin (e.g., having a thickness that is substantially smaller than the width and height of the strip and substantially smaller than a width or diameter of the optional reinforcing elements). Additional examples of features of the support strip <NUM> are described below with respect to <FIG>.

For example embodiments that include reinforcing elements, the reinforcing elements may include a string, a cord, and/or a relatively thick suture (e.g., an Ethibond suture), which may be substantially wider/thicker and/or have a substantially larger diameter (e.g., at least twice as wide/thick and/or have twice the diameter) than stitching sutures (e.g., primary sutures, secondary sutures, described in more detail below, tertiary sutures, described in more detail below, and/or other sutures of the commissure). The reinforcing elements may be substantially the same height (or slightly shorter, such as <NUM>-<NUM>% shorter to provide for machining tolerances and avoid extension of the inner reinforcing element past edges of the strip) as the height of the support strip. In other examples, the reinforcing elements can be a relatively narrow strip(s) of fabric, which can be folded lengthwise one or more times to increase its overall thickness. In still other examples, the reinforcing elements can be a metal wire(s) or a bar(s), such as a rectangular or cylindrical bar(s), formed from a metal and/or a polymer.

The reinforcing elements may include two individual reinforcing elements or two portions of a single reinforcing member that extends along outer surfaces of each of the first and the second commissure tabs 220a/b (or 420a/b of <FIG>). For example, a reinforcing member may be folded into a U-shape configuration to form the reinforcing elements (e.g., the reinforcing elements may be individual elements that are coupled to one another and/or form different sections of a single continuous element/member). In other examples, a reinforcing member may be discontinuous and include the reinforcing elements as discrete or separate elements in a spatially separated configuration (e.g., where a first reinforcing element is spatially separated from a second reinforcing element).

In some examples, the reinforcing elements may be aligned with one or more alignment markings and/or suture/stitching lines of the support strip. In some embodiments, the reinforcing elements are placed against outer surfaces of the commissure tabs, respectively, and opposing end or side portions of the support strip are positioned on an opposing side(s) of the reinforcing elements from the respective commissure tabs. For example, each reinforcing element may be sandwiched between a respective portion of the support strip and a respective one of the commissure tabs. In other embodiments, the support strip is at least partially wrapped or folded around the reinforcing elements to at least partially encase the reinforcing elements. In such examples, the portions of the support strip that at least partially encase the reinforcing elements may be placed against the outer surfaces of the commissure tabs, respectively.

Returning to the formation of the pre-assembled commissure, additional, secondary sutures 260a and 260b may be extended, each, in order (or in the reverse order): between inner secondary suture lines 262a and 262b (respectively), through the support strip <NUM>, optionally through the respective reinforcing elements 240a and 240b (respectively, when included in the commissure), through the commissure tabs 220a and 220b (respectively) and finally along (e.g., through apertures/markings of) the outer secondary suture line 264a and 264b (respectively) of a mid-portion of the support strip <NUM>.

<FIG> shows another example of secondary sutures 460a and 460b forming stitches passing from secondary suture lines 462a and 462b, respectively (e.g., through central alignment markings of the support strip <NUM>), to secondary suture lines 464a and 464b, respectively (e.g., through central alignment markings of the support strip <NUM>), where the sutures 460a and 460b each pass through one or more layers of the central region of the support strip <NUM>, reinforcing elements 440a and 440b (respectively), commissure tabs 420a and 420b (respectively), and one or more layers of the end portions of the support strip <NUM> (respectively).

As will be described in more detail below with respect to <FIG>, in the presently claimed invention, the support strip includes two layers of material (a main body portion and a tab portion of the strip that is folded over a central region of the main body of the strip) between the commissure tabs and the support structure to which the commissure is to be attached. Accordingly, the sutures 260a and 260b of <FIG> extend through both of the above-described layers of the support strip (e.g., the main body and the tab portion). As shown in <FIG>, sutures 460a and 460b extend through both the main body of the support strip <NUM> and a tab portion <NUM> of the support strip.

End portions of the support strip may be at least partially folded over themselves in some examples, creating two layers of material in a region of the commissure toward the leaflets and away from the support structure (e.g., support post <NUM>). In such examples, the secondary sutures 260a and 260b (and secondary sutures 460a and 460b of <FIG>) may be positioned as shown and extend through both of the above-described layers. Secondary sutures 260a' and 260b' in <FIG> show example alternative placements for the secondary sutures 260a and 260b, respectively. The alternative secondary sutures 260a' and 260b' pass through only one of the above-described layers of the support strip (e.g., a layer closest to the support post <NUM>). In still other examples, secondary sutures may be positioned in both locations (e.g., a combination of four or three of the sutures 260a, 260b, 260a', and 260b' may be used) in order to provide additional reinforcement of the coupling of the support strip to itself and the commissure tabs 220a and 220b.

The pre-assembled commissure tab assembly, assembled as described in any of the examples above,is attached to a corresponding commissure post <NUM> (or other commissure support structure) of the frame. The commissure post <NUM> can be a component of an actuator <NUM> of the prosthetic valve <NUM>. For example, the upper portion of outer member <NUM> (<FIG>) can serve as the commissure post <NUM>. In alternative embodiments, the prosthetic valve <NUM> can include commissure posts separate from the actuators. The separate commissure posts can be mounted to the inner surface of the frame <NUM>, or can be integral portions of the frame, at locations circumferentially spaced from the actuators.

The commissure tab assembly may be attached to the commissure post <NUM> by extending a tertiary suture <NUM> through tertiary suture lines <NUM> formed along the support strip <NUM> (e.g., each of two opposing sides of the support strip) adjacent two circumferentially opposite sides of the commissure post <NUM>, for example by forming shoelace stitches around the post <NUM> and knotting both ends of the suture <NUM> (e.g., forming a knot <NUM> at the top and/or bottom end). The stitches formed by tertiary suture <NUM> extend between opposing sides of the support strip across a first side of the post <NUM>, and may optionally extend at least <NUM> degrees around the post <NUM>.

In some examples, the tertiary suture lines may be spaced from (e.g., and provided in addition to) other suture lines (e.g., primary suture lines, such as lines 452a/452b of <FIG>, and/or secondary suture lines, such as lines 262a of <FIG> and/or lines 462al462b of <FIG>). In alternative examples, the tertiary suture lines may at least partially (or, in some examples, fully) overlap or include other suture lines of the support strip (e.g., by utilizing the same apertures and/or by extending in alignment with the other suture line(s), such as having apertures used for tertiary sutures being interspersed with apertures used for primary and/or secondary sutures).

In some examples, as shown in <FIG>, the tertiary sutures <NUM> may only extend through support strip material, such as portions of the support strip that extend beyond an end portion of the commissure tabs 220a and 220b. In other examples, the tertiary sutures <NUM> may further extend through the commissure tabs (e.g., in addition to extending through the support strip as shown in <FIG>). In such examples, the tertiary sutures may pass through one or more layers of the support strip that are adjacent to a first commissure tab (which may be disposed on opposing sides of the first commissure tab), through the first commissure tab, across a surface of the support post <NUM>, through one or more layers of the support strip that are adjacent to a second commissure tab (which may be disposed on opposing sides of the second commissure tab), and through the second commissure tab.

As described above, <FIG> shows a primary suture <NUM> and two secondary sutures 460a and 460b extending between inner secondary suture lines 462a and 462b (respectively) and outer secondary suture lines 464a and 464b (respectively). As shown in <FIG>, the outer secondary suture lines 464a and 464b are relatively close to each other. This proximity prevents marking holes formation along the positions of suture lines 464a and 464b - as marking holes in such proximity may compromise cloth integrity.

As briefly described above, according to an aspect of the disclosure, there is provided a flexible cloth (e.g., a support strip) comprising a main body portion and a foldable tab extending from one edge of the main body portion, centered therewith, wherein the tab comprises marking holes for the outer secondary suture line.

<FIG> shows an example of a support strip <NUM> that may be used in a commissure of a prosthetic valve of the present disclosure. The support strip <NUM> may be one example of the support strip <NUM>/<NUM> of <FIG>. The support strip <NUM> comprises a main body portion <NUM> and a tab <NUM>. The main body portion <NUM> may be similar in its dimensions to the support strip <NUM>/<NUM> used in <FIG>. The tab <NUM> extends from the lower edge of the main body portion <NUM> (e.g., at a horizontal fold line of the support strip). The tab can have a length L similar to a width W1 of the main body portion <NUM>. The support strip <NUM> has a centerline C that includes a centerline of the tab <NUM> that is continuous with the widthwise centerline of the main body portion <NUM>. The width W2 of the tab <NUM> may be equal to or slightly smaller than the width of the commissure post or other support structure to which the commissure is to be secured. The support strip <NUM> can have a T-shape as shown in <FIG> prior to folding the tab <NUM>.

The tab <NUM> further comprises two lines or columns of indicia or markings for the placement of sutures, such as in the form of marking holes 564a and 564b, configured to mark the desired positions of the outer secondary suture lines when the tab <NUM> is folded over the main body portion <NUM>, as shown in <FIG>.

According to some embodiments, the main body portion <NUM> comprises additional indicia or markings for the placement of sutures, such as marking holes 552a and 552b, configured to mark the desired positions of the first suture line and the second suture line formed by the respective marking holes. The columns of marking holes 552a and 552b may be positioned on opposite sides of the tab <NUM> from one another. In some examples, the marking holes 552a and 552b may be symmetrical with respect to the centerline C of the main body portion <NUM>. The indicia or markings for suture placement described herein may comprise a plurality of pre-formed apertures or openings for receiving sutures (e.g., apertures or openings that extend at least partially through the support strip). In other examples, in lieu of or in addition to apertures, the indicia or markings for suture placement described herein can comprise a plurality of ink markings or other markings that are visible or otherwise provide a visual indication of locations for stitching (e.g., where the markings themselves do not form openings passing through the support strip, but rather indicate where sutures/stitching is to pass through the support strip to assemble the commissure). It is to be understood that the number of indicia for suture placement illustrated herein on the example support strips is exemplary, and any suitable number of stitching lines or other markings may be included on the support strip or other elements of the prosthetic valve (e.g., the commissure tabs, optional reinforcing elements, etc.) without departing from the scope of the disclosure.

According to some embodiments, the main body portion <NUM> and the tab <NUM> comprise alignment notches <NUM> and <NUM>, respectively, along opposing edges thereof. The alignment notches <NUM> and <NUM> are similarly shaped and dimensioned and are configured to align with each other when the tab <NUM> is folded over the main body portion <NUM> (see <FIG>), thereby facilitating alignment between the tab <NUM> and the main body portion <NUM>.

Advantageously, since the tab constitutes an additional cloth portion, not meant to carry load of the commissure assembly, it is possible to add marking holes thereto without compromising cloth integrity once the commissure is assembled and mounted on a post. For example, the marking holes may be provided on the tab instead of the main body such that a region of the main body that is covered by the tab after folding (as shown in <FIG>) does not include any marking holes. Moreover, the proposed configuration doubles the layer of the cloth having the outer secondary suture lines there along (e.g., where a first layer comprises the main body and a second layer comprises the tab with the marking holes), thereby actually strengthening this cloth layer.

According to some embodiments, the tab comprises a single line or column of markings, such as a single column of marking holes instead of two separate parallel lines of marking holes, configured to accept both outer secondary suture lines formed by marking holes 564a, 564b there along. An example of such a configuration is described below with respect to <FIG>.

<FIG> shows another embodiment of a flexible cloth <NUM> comprising a main body portion <NUM> and a tab <NUM> provided with two lines or columns of indicia or markings in the form of marking holes 764a and 764b. Unlike flexible cloth <NUM> of <FIG>, the cloth <NUM> is devoid of alignment notches. Alignment between the tab <NUM> and the main body portion <NUM> is alternatively achieved by suturing (e.g., passing sutures 760a and 760b through) alignment apertures <NUM> with matching apertures along the lines of marking holes 764a and 764b (see <FIG>), when the tab <NUM> is folded over the main body portion <NUM>.

In the illustrated example, the main body portion <NUM> includes only two alignment apertures <NUM> (e.g., for alignment with corresponding marking holes from each line formed by marking holes 764a and 764b). In other examples, the main body portion <NUM> may include more or fewer alignment apertures.

<FIG> shows another embodiment of a flexible cloth <NUM> comprising a main body <NUM> and a tab <NUM>. The main body <NUM> includes marking hole-lines 852a and 852b and, optionally, supplemental marking hole-lines 854a and 854b. Unlike flexible cloths <NUM> or <NUM> of <FIG> and <FIG>, respectively, the tab <NUM> is provided with a single suture line <NUM>. This embodiment allows a suture to extend, when stitched back and forth, through the same holes along the suture line <NUM>.

It is to be understood that any of the above-described example support strips of <FIG> may be used in a commissure assembly as described above with respect to <FIG>.

Advantageously, since the tab of the present disclosure constitutes an additional cloth portion, which may not be relied upon to carry the load of the commissure assembly, it is possible to add marking holes thereto without compromising cloth integrity once the commissure is assembled and mounted on a post. Moreover, the proposed configuration doubles the layer of the cloth having the outer secondary suture lines there along, thereby actually strengthening this cloth layer.

<FIG> is a flow chart of an example method <NUM> of assembling a commissure. For example, method <NUM> may be performed to assembly any of the example commissures described herein. At <NUM>, the method includes coupling (e.g., securing and/or attaching) a support strip to a pair of commissure tabs (corresponding to a pair of leaflets of a prosthetic valve) by stitching primary sutures through edge alignment markings (e.g., markings 262a/262b and 462al462b of <FIG>) of the support strip.

In the presently claimed invention, the support strip is configured to include a main portion and a tab extending from the main portion (in a central region of the main portion). For example, the support strip may be configured as described above with respect to support strip <NUM> of <FIG>, support strip <NUM> of <FIG>, support strip <NUM> of <FIG>, support strip <NUM> of <FIG>, and/or support strip <NUM> of <FIG>. Accordingly, the main portion of the support strip may include a central region (from which the tab extends) and two opposing side regions disposed on opposite sides of the central region from one another. Securing the support strip to the commissure tabs may include attaching each of the opposing sides of the main portion of the support strip to a respective one of the commissure tabs.

As indicated at <NUM>, the primary sutures may be stitched through a first set of edge alignment markings on a first side of the main body to (and through) a second set of edge alignment markings on a second side of the main body (e.g., on an opposite side of the main body from the first side). Example edge alignment markings are shown at 552a/552b of <FIG> and 852a/852b of <FIG>. Suture lines 452a/452b of <FIG> may also be formed of markings that correspond to example edge alignment markings.

In some examples, where reinforcing members are used, such as reinforcing elements 240a and 240b illustrated in <FIG> and/or reinforcing elements 440a and 440b of <FIG>, the primary sutures may also extend through the reinforcing members, as indicated at <NUM>.

At <NUM>, the method includes folding a tab portion of the support strip over the main body of the support strip, aligning in accordance with strip alignment indicators. The tab portion may be folded at a horizontal fold line such that the tab portion overlaps a center portion of the main body of the support strip. For example, the support strip may be T-shaped before folding. In some examples, the height of the main body of the support strip (e.g., the top, horizontal portion of the T-shape) may be smaller than or the same as the height of the tab portion (e.g., the bottom, vertical portion of the T-shape). In other examples, the height of the main body of the support strip may be larger than the height of the tab portion. In the any of the above described examples, the width of the tab portion of the support strip may be smaller than or the same as the width of the main body. After folding the tab portion over the central portion of the main body, the support strip may be substantially rectangular. As indicated at <NUM>, the strip alignment indicators may include markings, notches, and/or apertures. Examples of markings and/or apertures are shown at 564al564b of <FIG>, 764al764b of <FIG>, and <NUM> of <FIG>. Examples of notches are shown at <NUM>/<NUM> of <FIG>.

At <NUM>, the method includes attaching the tab portion of the support strip to the main body by stitching secondary sutures through central alignment markings. In some examples, the central alignment markings may include one or more of the strip alignment indicators (e.g., in examples where the strip alignment indicators include markings and/or apertures, the strip alignment markings and/or apertures may also be used as at least some of the central alignment markings. Examples of central alignment markings may include one or more of markings 564a/564b of <FIG>, markings <NUM> and 764a/764b of <FIG>, and markings 854a/854b and/or <NUM> of <FIG>. Suture lines through which sutures 260a/260b of <FIG> pass and suture lines 462a/462b and 464al464b of <FIG> may also be formed of markings that correspond to example edge alignment markings.

As indicated at <NUM>, the attachment may include stitching the secondary sutures through an inner set of central alignment markings of the main body and/or tab portion of the support structure to (and through) an outer set of central alignment markings of the main body and/or tab portion of the support strip. For example, suture lines 262a/262b of <FIG> (or correspondingly suture lines 462al462b of <FIG>) may be formed of markings that are examples of an inner set of central alignment markings, while suture lines 264a/264b of <FIG> (or correspondingly suture lines 464al464b of <FIG>) may be formed of markings that are examples of an outer set of central alignment markings (or vice versa - 262a/262b/462a/462b may correspond to the outer set while 264a/264b/464a/464b may correspond to the inner set).

At <NUM>, the method includes securing the commissure to a support post and/or another element of a frame of the prosthetic valve in which the commissure is disposed. As indicated at <NUM>, securing the commissure to the support post may include stitching tertiary sutures through tertiary suture lines of the support strip and around the support post. Example tertiary sutures are shown at <NUM> and example tertiary suture lines are shown at <NUM> in <FIG>. As further shown in <FIG>, the securing of the commissure to the support post may further include coupling end portions of the tertiary suture to one another (e.g., via a knot, such as knot <NUM>). In some examples, one or more of the markings of the support strip examples of <FIG> and/or additional markings of the support strip may be used to mark tertiary suture lines.

Claim 1:
A method of assembling a prosthetic heart valve comprising a plurality of leaflets, the method comprising:
forming a plurality of commissures with the plurality of leaflets, wherein each commissure is formed by:
pairing a first commissure tab of a first leaflet with an adjacent, second commissure tab of a second leaflet,
coupling (<NUM>) a main body of a support strip to the first and second commissure tabs via primary sutures, wherein coupling the main body of the support strip to the first and second commissure tabs includes stitching the primary sutures through, in order or in reverse order: a first side of the main body of the support strip, the first commissure tab, the second commissure tab, and a second side of the main body of the support strip,
folding (<NUM>) a tab portion of the support strip over a central region of the main body, and
coupling (<NUM>) the tab portion of the support strip to the central region of the main body via secondary sutures; and
for each commissure, securing (<NUM>) the commissure to a respective support portion of a frame of the prosthetic heart valve;
wherein the main body of the support strip and the tab portion of the support strip are positioned between the commissure tabs and the respective support portion of the frame of the prosthetic heart valve.