Patent Description:
The present invention relates to a prosthetic valve for use in the human heart. More specifically, the invention relates to a tri-leaflet prosthetic heart valve that may be used in percutaneous valve replacement procedures.

Heart valve replacement is the second most common cardiac operation performed in the United States. Currently, over four million people are diagnosed with heart valve disorder across the world, each year. Moreover, heart disease is prevalent in about <NUM>% of the overall United States population, and <NUM>% of its elderly population.

Typically, prosthetic heart valves used in aortic heart valve replacement procedures are either mechanical or bioprosthetic. However, these valves introduce significant risk of thromboembolism, requiring the patient to undergo lifelong anticoagulation therapy, or the patient become more prone to valve degeneration and tissue failure, requiring reoperation. <CIT> provides another cardiac valve with a support frame and a cover extending over the support frame to allow for unidirectional flow of a liquid through the valve. It would be useful to produce a prosthetic heart valve that would be durable, while not necessitating anticoagulation therapy.

The present invention provides a transcatheter prosthetic heart valve according to the appeded claims.

A transcatheter prosthetic heart valve including a stent frame having a top portion and a bottom portion; and a tube of leaflet material configured to encircle the stent frame is provided. The tube of leaflet material includes a lower portion disposed about an exterior surface of the stent frame; and an upper portion that is at least partially disposed within an interior surface of the stent frame; and wherein the upper portion disposed within the stent frame forms at least one leaflet capable of moving from a first position to a second position within the stent frame.

Moreover, at least a portion of the upper portion of the leaflet material is configured to wrap around a connection point of the top portion and to fold towards the interior surface of the stent frame. And, at least a second portion of the tube of leaflet material is configured to weave under an upper edge of the top portion of the stent frame, folding towards the interior surface of the stent frame.

In one embodiment, the tube of leaflet material is formed from a continuous sheet of leaflet material, and an upper edge of the continuous sheet of leaflet material comprises at least three arches extending upwardly therefrom. Alternatively, the tube of leaftlet material may be formed from two or more pieces of leaflet material.

In another embodiment, the upper edge of the continuous sheet of leaflet material comprises a space between every two directly adjacent arches of the at least three arches.

In another embodiment, the tube of leaflet material is extruded so that the tube does not have a side seam. The material may be made of a polymer material. That polymer material may be linear low density polyethylene, polytetrafluoroethylene, low-density polyethylene, polyethylene terephthalate, polypropylene, polyurethane, polycaprolactone, polydimethylsiloxane, polymethylmethacrylate, polyoxymethylene, thermoplastic polyurethane, and combinations thereof. The leaflet material may further include a polymer material and hyaluronic acid. It may also include a bioprosthetic material.

In another embodiment the leaflets may have a three dimensional curvature or a two dimensional curvature.

The stent frame may be self-expandable or may be expanded manually using a balloon. The stent frame may have a height and an inner diameter, wherein a ratio of the height to the inner diameter is in a range between about <NUM> and about <NUM>. However, it should be appreciated that the stent may be made to conform to the natural geometry of the patient's body.

The disclosed embodiments are directed to a prosthetic heart valve. In particular, a prosthetic heart valve having a tri-leaflet design for use in a percutaneous (or transcatheter) valve replacement procedure (hereinafter "TPHV") in order to replace either a failing or damaged native aortic or mitral heart valve in a patient is provided. Although a TPHV with a tri-leaflet design will be described herein, it should be apparent to one of skill in the art that any number of leaflets may be made using the TPHV. The TPHV disclosed herein may generally include one or more leaflets disposed on a stent frame, as shown in <FIG>. The leaflets are configured simulate a patient's native leaflets and to open and close in response to the pumping of the heart. When leaflets are closed, as shown in <FIG>, the commissures meet to ensure minimal reverse flow of the blood.

In certain embodiments, the TPHV will provide a prosthetic valve with a higher effective orifice compared to other prosthetic valves that are commercially available. In certain embodiments, the TPHV will provide improved flow characteristics through the geometric design of both the stent frame and the leaflet. The designs of the stent frame in combination with the designs of the leaflet(s) enable improved performance over other commercially available prosthetic valves. For example, the designs of the leaflet(s) and/or the manners in which the leaflet(s) is disposed on the stent frame may improve durability of the TPHV, reduce the number of sutures required to assemble the leaflet(s), and/or improve leaflet coaptation.

Referring now to <FIG>, <FIG> illustrates a perspective view of on embodiment of the TPHV <NUM> including a stent frame <NUM> and a sheet of leaflet material <NUM> (as shown in <FIG>) formed in to a tube of leaflet material. <FIG> is an exploded view of the TPHV <NUM> of <FIG>, showing the stent frame or frame <NUM> and the sheet of leaflet material <NUM>.

As illustrated in <FIG> and <FIG>, the stent frame <NUM> includes an interior or an inner surface <NUM>, an exterior or outer surface <NUM>, a top portion <NUM> having a top edge <NUM>, and a bottom portion <NUM>. The tube of leaflet material <NUM> may be disposed on the exterior <NUM> of the stent frame <NUM>. However, as the tube of leaflet material <NUM> is placed on to the stent frame <NUM> by sliding the tube onto the stent frame <NUM> from the bottom portion <NUM> of the frame to the top portion <NUM>, in proximity to the top edge <NUM> of the top portion <NUM>, the tube of leaflet material <NUM> is configured to bend or fold towards the interior <NUM> of the stent frame <NUM>. In the illustrated heart valve , an upper portion <NUM> of the tube of leaflet material <NUM> bends or folds around a first portion <NUM> of the top portion <NUM> of the stent frame <NUM> and tucks or is woven under a second portion <NUM> of the top portion <NUM> of the stent frame <NUM> at its top edge <NUM> (e.g., at least a portion of the sheet of the leaflet material <NUM> weaves through the stent frame <NUM>) to form leaflets <NUM>, while a lower portion <NUM> of the tube of leaflet material <NUM> is disposed on the exterior <NUM> of the stent frame <NUM>. In the illustrated heart valve , the second portion <NUM> of the top portion <NUM> of the stent frame <NUM> is disposed between upper connection points <NUM> of the stent frame <NUM>, which connect the top portion <NUM> of the stent frame to a middle (not shown) or bottom portion <NUM> of the stent frame <NUM>.

Herein, the part of the leaflet material <NUM> that wraps under the top edge <NUM> of the stent frame <NUM> and folds towards the interior <NUM> of the stent frame <NUM> is referred to as a leaflet <NUM>. As set forth above, the TPHV may have a tri-leaflet design or other designs with any suitable number of leaflets. The leaflets <NUM> may flex generally in a first direction <NUM> and open to a first position to allow forward flow of blood and may flex generally in a second direction <NUM> to close to a second position and block reverse flow of the blood. When the leaflets <NUM> are closed, commissures <NUM> (as shown in <FIG>) meet to ensure minimal reverse flow of the blood.

The tube of material <NUM> woven through the stent frame <NUM>, and thus forming leaflets <NUM>, is to a degree constrained by the top edge <NUM> of the stent frame <NUM>. In addition, the geometry and/or design of the top edge <NUM> may contribute to shaping the leaflet material <NUM> into desired shapes of the leaflets <NUM> for better coaptation. As a result, the number of sutures required to assemble the TPHV <NUM> may be significantly reduced.

Furthermore, as the sheet of leaflet material <NUM> is woven through the stent frame <NUM>, at least a portion (e.g., the second portion <NUM>) of the top edge <NUM> may provide mechanical support and/or reinforcement as the leaflets <NUM> go through cycles of opening and closing, which may result in improved durability of the TPHV <NUM>.

With the foregoing in mind, the stent frame <NUM> may be formed of a single piece of material or it may be formed of multiple wires which are welded, or otherwise suitably connected, to form a single stent frame <NUM>.

The stent frame <NUM> may have various geometric designs. With regard to the stent frame shown in <FIG>, and with specific reference to <FIG>, the stent frame may include a top portion <NUM> comprised of undulating plurality of similarly sized wires or struts <NUM>, connected at the respective apexes <NUM>. The stent frame <NUM> may further include a bottom portion <NUM> including a plurality of wires or struts formed in to a repeating diamond <NUM> pattern. Between the top portion <NUM> and the bottom portion <NUM>, the stent frame <NUM> may further include a set of struts formed in to V-shaped struts <NUM> extending downwardly from the top portion <NUM> and disposed between the apexes <NUM> of the top portion <NUM>. And finally, the stent frame <NUM> may include a set of struts formed in to inverted V-shaped struts <NUM> disposed between two of the diamonds <NUM> formed in to the bottom portion <NUM> and connected to the top portion <NUM> of the stent frame <NUM> at connection points <NUM>. Each of the connection points <NUM> may be located at each of the apexes <NUM> of the top portion <NUM>.

The top portion <NUM>, bottom portion <NUM>, and middle V-shaped struts <NUM>, <NUM> together form three primary units X of the stent frame <NUM>; however, the stent frame <NUM> may include less than or more than three units X as appropriate.

As shown in <FIG>, <FIG>, <FIG>, the ends of the flat stent frame are connected to form a tubular stent frame <NUM> that can be inserted into the body of a patient. The stent frame <NUM> may be made of stainless steel, nitinol, cobalt chromium, or other suitable material. It should be understood that the shape of the frame <NUM> may be generally circular in nature or it may be elliptical, oval, or other shape suitable to the curvature of the patient's valve annulus.

Referring now to <FIG>, the tube of leaflet material <NUM> of the TPHV <NUM> may be created using a single piece of polymeric or bioprosthetic (such as porcine or bovine pericardium) material. It will also be understood that the tube of leaflet material <NUM> may also be created using separate pieces of leaflet material affixed between each unit X of the stent frame <NUM>.

As shown in <FIG>, a continuous sheet of leaflet material <NUM> may include an upper edge portion <NUM> and a lower edge portion <NUM>. The lower edge portion <NUM> may be generally rectangular in shape. The upper edge portion <NUM> may be generally rectangular in shape, or as will be discussed below and shown in <FIG>, the upper edge portion may include at least one arch <NUM> extending upwardly therefrom.

The leaflet material <NUM> may be made of a polymeric material, such as linear low density polyethylene (LLDPE), polytetrafluoroethylene (PTFE), low-density polyethylene (LDPE), polyethylene terephthalate (PET), polypropylene (PP), polyurethane, polycaprolactone (PCL), polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polyoxymethylene (POM), thermoplastic polyurethane, and combinations thereof. The leaflet material <NUM> may be made of a polymeric material, such as LLDPE, that includes hyaluronic acid to prevent blood clot and thrombosis formation. An example of this material is disclosed in <CIT>, entitled Glycosaminoglycan and Synthetic Polymer Material for Blood-Contacting Applications.

As set forth above, the leaflet material <NUM> may be woven through each unit X of the frame <NUM>. Specifically, the leaflet material <NUM> may be woven through the frame <NUM> so that a majority of the material <NUM> is disposed on the outer surface <NUM> of the frame <NUM> and a portion of the material <NUM> is tucked inside the frame <NUM> between the upper connection points <NUM>, as shown in <FIG>. In doing so, the leaflets <NUM> are formed and disposed with their outer surface against the inner surface <NUM> of the frame <NUM>.

In one embodiment, the leaflet material <NUM> is secured to the frame <NUM> by suturing the material <NUM> to the frame <NUM> at the connection points <NUM> between the top portion <NUM> and the inverted V-shaped struts <NUM> and between every other diamond <NUM> of the bottom portion <NUM>. By using a single continuous piece of leaflet material <NUM> mounted around the stent frame <NUM>, the number of sutures required to assemble the leaflets <NUM> is reduced. However, it should be appreciated that more sutures may be used at any point on the stent frame or that multiple pieces of leaflet material may be mounted about the circumference of the stent frame <NUM>.

As shown in <FIG>, the leaflet material <NUM> may include the upper edge portion <NUM> with a plurality of arches <NUM> (e.g., at least two arches <NUM>, at least three arches <NUM>). It should be understood that the arches <NUM> may be formed integrally with the single sheet of leaflet material <NUM> or may be attached to the upper edge portion <NUM> after the material is formed. The arches <NUM> on the upper edge portion <NUM> provide arched leaflets <NUM> when wrapped around the stent frame <NUM>. Through the use of arched leaflets <NUM>, it was discovered that flow reattachment is facilitated and recirculation regions that are directly related to thrombus formation are decreased. In addition, the use of arched leaflets <NUM> provides an improved leaflet coaptation.

As shown in <FIG> and <FIG>, the leaflet material <NUM> may include one or more spaces or grooves <NUM> in the upper edge portion <NUM>, and the spaces or grooves <NUM> are disposed between each pair of directly adjacent arches <NUM>. The one or more spaces <NUM> are configured to improve coaptation of the leaflets <NUM>.

For example, the one or more spaces <NUM> may help to accommodate the opening and closing motions of the leaflets <NUM>, such that the commissures (e.g., the upper edge portion <NUM>) meet with better conformity to achieve better coaptation and ensure minimal reverse flow of the blood when the leaflets <NUM> are closed, as shown in <FIG>.

Referring again to <FIG>, the tube of leaflet material <NUM> may be woven through the stent frame <NUM> in a manner that each of the arches <NUM> is tucked in or folded under the second portion <NUM> of the top edge <NUM> while each of the spaces <NUM> is approximately aligned with the corresponding upper connection point <NUM>. As such, the one or more spaces <NUM> may provide flexibility and better conformity where the leaflet material <NUM> (the sheet of leaflet material <NUM>) transitions from portions that are tucked in under (at the second portion <NUM> of the top edge <NUM>) the stent frame <NUM> to portions that wrap around (at the first portion <NUM> of the top edge <NUM>) the stent frame <NUM>.

Once the sheet of leaflet material <NUM> is installed onto the stent frame <NUM>, the leaflets <NUM> may be further formed or shaped by applying a combination of heat and pressure to the once planar sheet of leaflet <NUM>. This treatment can be used to further change the shape of the sheet of leaflet <NUM> into a three dimensional configuration (as is the case for native valve leaflets) (not shown). In one embodiment, vacuum pressure is applied to the formed TPHV <NUM> on the upstream side of the TPHV <NUM> to force the sheet of leaflet <NUM> (the leaflets <NUM> in particular) to close. Subsequently, heat is applied from the downstream side in order to make the polymer (which is a thermoplastic) relax and stretch under the forces exerted by the vacuum. The resulting shape of the sheet of leaflet <NUM>, and the leaflets <NUM> in particular, may more closely resemble the patent's native leaflet shape.

As will be appreciated from the description below, the stent frame may have different geometric designs, examples of which are shown in <FIG>, that allow at least a portion of the leaflet material to be disposed about the exterior of the stent frame, while at least another portion is woven within the stent frame to form leaflets on the interior surface.

Referring now to <FIG>, and <FIG>, and with specific reference to <FIG>, a stent frame <NUM> may include a top, middle, and bottom row of wires (<NUM>, <NUM>, <NUM>) and a set of wire connectors (120a, 120b, 120c) that together form the three primary units X of the stent frame <NUM>. The top row <NUM> of the frame <NUM> is comprised of an undulating plurality of similarly sized medium-length wires (or struts) <NUM>, connected at the respective apexes <NUM>. The wires (or struts) may be welded together or may be formed of a single piece of laser cut material.

Here, the top row <NUM> includes twelve such wires of about <NUM> millimeters (mm) in length - four wires in each unit X of the stent frame. In the illustrated stent frame, the stent frame <NUM> includes at least three units X; however, the stent frame <NUM> may include less than or more than three units X as appropriate.

The middle row <NUM> is generally comprised of a plurality of similarly sized extended-length wires <NUM>, connected to one another at the respective apexes <NUM>. Here , the middle row <NUM> includes six such wires of about <NUM> in length - two wires in each unit X of the stent frame <NUM>.

The bottom row <NUM> is generally comprised of a plurality of similarly sized short-length wires <NUM>, connected to one another at the respective apexes <NUM>. Here, the bottom row <NUM> includes twenty-four such wires of about <NUM> in length - eight wires in each unit X of the stent frame <NUM>.

When assembled, the middle row of wires (or struts) <NUM> is connected to the top row <NUM> by connecting each upwardly extending apex <NUM> of the middle row <NUM> to every other upwardly extending apex <NUM> of the upper row <NUM> to form three upper connection points <NUM> - one in each unit X. And, the middle row <NUM> is connected to the bottom row <NUM> by connecting each downwardly extending apex of the middle row <NUM> to every first and fifth upwardly extending apex <NUM> of the bottom row <NUM> to form lower connection points <NUM> - two in each unit X.

The stent frame <NUM> also includes a secondary set of wire connectors (120a, 120b, 120c) that are connected to the bottom row <NUM>. The secondary set of wire connectors 120a, 120b, 120c may have a first terminal end <NUM> and second terminal end <NUM> that are connected to every second and fourth upwardly extending apex of the bottom row <NUM> to form secondary connection points <NUM> - two in each unit X. Generally, the secondary connectors 120a, 120b, 120c are shaped to extend upwardly from each terminal end <NUM>, <NUM> along first and second struts <NUM> and <NUM> and to connect at a pinnacle <NUM> along a third and fourth strut <NUM>, <NUM> in a roof-shaped design.

The stent frame <NUM> shown in <FIG>, and <FIG> may include specially formed slots to help securing the sheet of leaflet material to the stent frame <NUM>. As shown in <FIG>, the stent frame <NUM> is similar to that shown in <FIG>, and includes slots <NUM> in the extended length wires <NUM>.

Moreover, as shown in <FIG>, when applied to the stent frame <NUM>, the tube of leaflet material may be created using separate pieces of leaflet material that may be attached to each unit X of the stent frame <NUM> by inserting extensions from the material (not shown) into the specially formed slots <NUM> (shown in <FIG>) in the extended length wires <NUM>.

Referring now to <FIG>, and <FIG>, the stent frame <NUM> includes three rows of connectors. Specifically referring to <FIG>, the stent frame <NUM> may include a first set of three large roof-shaped upper connectors <NUM> (e.g., top row), a second set of three medium sized roof-shaped middle connectors <NUM> (e.g., middle row), a row of honey-comb shaped wires <NUM> forming the bottom of the stent frame <NUM> (e.g., bottom row). As an example, the stent frame <NUM> may have dimensions in millimeters (mm) as shown in <FIG> (e.g., each of the upper roof-shaped upper connectors <NUM> may be about <NUM> in length, each of the roof-shaped middle connectors <NUM> may be about <NUM> in length, etc.).

The frame may have another geometric design, illustrated as a stent frame <NUM> shown in <FIG>. The stent frame <NUM> may include a top row <NUM> of wires, a middle row <NUM>, a bottom row <NUM> of wires, a first set of connectors <NUM> connecting the top row <NUM> of wires to the middle row <NUM> of wires, and a second set of connectors <NUM> connecting the middle row <NUM> of wires to the bottom row <NUM> of wires. The top row <NUM> of wires may include undulating plurality of similarly sized wires or struts. The middle row <NUM> of wires and the first set of connectors <NUM> may form a repeating roof-shaped design. The bottom row <NUM> of the wires may form a repeating diamond-shaped pattern or design.

The stent frame <NUM> may also include slots <NUM> in the middle row <NUM> of wires. The slots <NUM> may help securing the sheet of leaflet material to the stent frame <NUM> in a similar manner that the slots <NUM> help secure the sheet of leaflet material to the stent frame <NUM> as set forth above in <FIG>.

The stent frame may also have another geometric design, illustrated as a stent frame <NUM> shown in <FIG>, and <FIG>. Here, the stent frame <NUM> may include a top row of wires or struts <NUM>, a middle row of wires or struts <NUM>, and a bottom row of wires or struts <NUM>. The top row of wires <NUM> includes an undulating plurality of similarly sized wires or struts <NUM>, connected at the respective apexes <NUM>. The middle row of wires <NUM> includes one or more pairs of upward-extending wires <NUM> connected at the respective apexes <NUM>. The bottom row of wires <NUM> may form a repeating diamond shaped design with a plurality of diamonds <NUM> of a similar size.

Each of the one or more pairs of upward-extending wires <NUM> is connected to the top row of wires <NUM> at the respective apexes <NUM>. For example, a short wire may connect the respective apex <NUM> of the top row of wires <NUM> to the respective apex <NUM> of the upward-extending wires <NUM>. Each of the diamonds <NUM> in the bottom row <NUM> may be connected to the respective upward-extending wire <NUM> at the respective corner <NUM> of the diamond <NUM>.

The stent frame may also have another geometric design, illustrated as a stent frame <NUM> shown in <FIG>. Here, the stent frame <NUM> may include a lower portion <NUM> and an upper portion <NUM> for use for supra-annular deployment. Specifically, the lower portion <NUM> may be designed in any of the configurations disclosed herein with regard to stent frames <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>, and a combination thereof.

Here, the lower portion <NUM> may be connected to the upper portion <NUM> by a plurality of vertical wire portions <NUM>. The upper portion <NUM> may include one or more undulating wires <NUM> configured to allow connecting the stent frame <NUM> at a higher point in a patient's aorta, depending on the geometry of the patient's anatomy.

As shown in <FIG>, the stent frame <NUM> is configured with capability to expand and retract in the radial direction of the stent frame <NUM> as appropriate. As may be appreciated, any other designs of the stent frame disclosed herein (e.g., stent frames <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) are also configured to expand and retract in the radial direction as appropriate. In practice, the TPHV <NUM> may be crimped onto a balloon catheter or any other suitable delivery device by any suitable method known in the art. The TPHV <NUM> may also be deployed as a self-expandable stent with a suitable delivery device. It should be appreciated that due to the unique geometry of the stent frame (e.g., the stent frames <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>), there is less chance for the sheet of leaflet material (the leaflet material <NUM>) to be ripped or stretched when crimped on to the delivery device. In addition, the geometries of the stent frame (e.g., the stent frames <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) allow the TPHVs <NUM> to be crimped in to a smaller diameter than other commercially available devices. The TPHVs <NUM> disclosed herein may have an inner diameter and a height (e.g., along the axial direction), and the ration of the height to the inner diameter is in a range between about <NUM> and about <NUM>, when the TPHVs <NUM> are substantially fully expanded.

It should also be appreciated that the tube of leaflet material (the leaflet material) may be disposed on the stent frames (e.g., the stent frames <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) disclosed herein in a similar manner as set forth above in <FIG>, <FIG>, <FIG>. In particular, the tube of leaflet material (the leaflet material) is woven through the stent frame disclosed herein (e.g., the stent frames <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) as appropriate. For example, at least a portion of the sheet of leaflet material may be tucked in under the top row of wires as the sheet of leaflet material is woven through the stent frame. At least a portion of the sheet of leaflet material (the leaflet material) may be tucked in under the top row of wires between the first set of connectors.

The sheet of leaflet material (the leaflet material) is disposed on the exterior of the stent frame and generally wrap around the top edge portion and bend or fold towards the interior of the stent frame and at least a second portion of the tube of leaflet material weaves under an upper edge of the top portion of the stent frame. The stent frames disclosed herein (e.g., the stent frames <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>) may be used in combination with an outer skirt to prevent leaking.

Claim 1:
A transcatheter prosthetic heart valve (<NUM>), comprising:
a stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising a top portion (<NUM>) and a bottom portion (<NUM>); and
a tube of leaflet material (<NUM>) configured to encircle the stent frame (<NUM>); wherein the tube of leaflet material comprises (<NUM>):
a lower portion (<NUM>) disposed about an exterior surface (<NUM>) of the stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and
an upper portion (<NUM>) that is at least partially disposed within an interior surface (<NUM>) of the stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and wherein the upper portion (<NUM>) disposed within the stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) forms at least one leaflet (<NUM>) capable of moving from a first position to a second position within the stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein:
at least a portion of the upper portion (<NUM>) of the leaflet material (<NUM>) wraps around a connection point (<NUM>) of the top portion (<NUM>) and folds towards the interior surface (<NUM>) of the stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>); and
at least a second portion of the tube of leaflet material weaves under an upper edge (<NUM>, <NUM>) of the top portion (<NUM>) of the stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and folds towards the interior surface (<NUM>) of the stent frame (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>).,