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

Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two common types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve is first collapsed or crimped to reduce its circumferential size. It is therefore desirable that the valve have a low profile or volume to minimize the size of the delivery apparatus.

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 For self-expanding valves, on the other hand, the stent automatically expands as a sheath covering the valve is withdrawn.

There is a need for improvements to prosthetic heart valves, and specifically, to collapsible prosthetic heart valves that would reduce the likelihood of paravalvular leakage due to gaps between the implanted prosthetic heart valve and patient tissue.

<CIT> describes an expandable sealing means for endoluminal devices developed for controlled activation. The devices have a low profile mechanism (for both self-expanding and balloon-expanding prostheses), contained, not open, release of the material, active conformation to the "leak sites" such that leakage areas are filled without disrupting the physical and functional integrity of the prosthesis, and on-demand, controlled activation, that may not be pressure activated.

Other devices with mechanisms for prevention of leakage are known from <CIT>, <CIT>, <CIT>, <CIT>.

In accordance with the present invention, there is provided a stent assembly for use in a prosthetic heart valve according to appended claim <NUM>.

Various aspects of the invention are proposed in the appended dependent claims.

Various embodiments of the presently disclosed stent assembly and prosthetic heart valves may be more fully understood with reference to the following detailed description when read with the accompanying drawings, in which:.

As used herein, the term "proximal," when used in connection with a prosthetic heart valve, refers to the end of the heart valve closest to the heart when the heart valve is implanted in a patient, whereas the term "distal," when used in connection with a prosthetic heart valve, refers to the end of the heart valve farthest from the heart when the heart valve is implanted in a patient. Like reference numbers refer to similar or identical elements throughout the disclosure.

<FIG> shows a collapsible stent-supported prosthetic heart valve <NUM> known in the art. The prosthetic heart valve <NUM> is designed to replace the function of a native tricuspid, bicuspid or unicuspid valve of a patient, such as a native aortic valve. It should be noted that while the embodiments herein are described predominately in connection with their use with a prosthetic aortic valve and a stent having a shape as illustrated in <FIG>, the embodiments may also be used with tricuspid valves, pulmonic valves, and bicuspid valves, such as the mitral valve, and with stents having different shapes, such as those having a flared or conical annulus section, a less-bulbous aortic section, and the like, and a differently shaped transition section.

The prosthetic heart valve <NUM> includes a stent constructed as a frame <NUM> from a plurality of attached cells <NUM>, which may be wholly or partly formed of any biocompatible material, such as metals, synthetic polymers, or biopolymers capable of functioning as a stent. Suitable biopolymers include, but are not limited to, elastin, and mixtures or composites thereof. Suitable metals include, but are not limited to, cobalt, titanium, nickel, chromium, stainless steel, and alloys thereof, including shape memory alloys known as Nitinol. Suitable synthetic polymers for use as a stent include, but are not limited to, thermoplastics, such as polyolefins, polyesters, polyamides, polysulfones, acrylics, polyacrylonitriles, polyetheretherketone, and polyaramides.

The stent <NUM> extends from a proximal or annulus end <NUM> to a distal or aortic end <NUM>, and includes an annulus section <NUM> adjacent the proximal end <NUM> and an aortic section <NUM> adjacent the distal end <NUM>. The annulus section <NUM> has a relatively small cross-section in the expanded condition, while the aortic section <NUM> has a relatively large cross-section in the expanded condition. The annulus section <NUM> may be in the form of a cylinder having a substantially constant diameter along its length. A transition section <NUM> may taper outwardly from the annulus section <NUM> to the aortic section <NUM>. Each of the sections of the stent <NUM> includes a plurality of cells <NUM> connected to one another in one or more annular rows around the stent <NUM>. For example, as shown in <FIG>, the annulus section <NUM> may have two annular rows of complete cells <NUM> and the aortic section <NUM> and the transition section <NUM> may each have one or more annular rows of complete or partial cells <NUM>. The cells <NUM> in the aortic section <NUM> may be larger than the cells <NUM> in the annulus section <NUM>. The larger cells <NUM> in the aortic section <NUM> better enable the prosthetic valve <NUM> to be positioned without the stent structure <NUM> interfering with blood flow to the coronary arteries. The cells <NUM> may be connected circumferentially to each other by runners <NUM> arranged about the stent <NUM>.

The stent <NUM> may include one or more retaining elements <NUM> at the distal end <NUM> thereof, the retaining elements <NUM> being sized and shaped to cooperate with retaining structures provided on a deployment device (not shown). The engagement of the retaining elements <NUM> with the retaining structures on the deployment device helps maintain the prosthetic heart valve <NUM> in assembled relationship with the deployment device, minimizes longitudinal movement of the prosthetic heart valve relative to the deployment device during unsheathing or resheathing procedures, and helps prevent rotation of the prosthetic heart valve relative to the deployment device as the deployment device is advanced to the target location and during deployment.

The stent <NUM> may also include a plurality of commissure points <NUM> for mounting the commissures (not identified), where two leaflets <NUM> come together to the stent <NUM>. As can be seen in <FIG>, the commissure points <NUM> may lay at the intersection of four cells <NUM>, two of the cells <NUM> being adjacent one another in the same annular row, and the other two cells <NUM> being in different annular rows and lying in end-to-end relationship. In one embodiment, the commissure points <NUM> are positioned entirely within the annulus section <NUM> or at the juncture of annulus section <NUM> and the transition section <NUM>. The commissure points <NUM> may include one or more eyelets which facilitate the suturing of the leaflet commissure to the stent.

The prosthetic heart valve <NUM> includes a valve assembly <NUM> preferably positioned in the annulus section <NUM>. The valve assembly <NUM> may be mounted to the stent <NUM> by suturing the commissures of the leaflets <NUM> to the commissure points <NUM> and suturing other portions of the valve assembly <NUM> to the stent <NUM>, or by other methods known in the art. The valve assembly <NUM> may include a cuff <NUM> and a plurality of leaflets <NUM> which collectively function as a one-way valve by coapting with one another. <FIG> illustrates a prosthetic heart valve for replacing a native tricuspid valve, such as the aortic valve. Accordingly, the prosthetic heart valve <NUM> is shown in <FIG> with three leaflets <NUM>, as well as three commissure points <NUM>. However, it will be appreciated that the prosthetic heart valves according to aspects of the disclosure may have a greater or lesser number of leaflets <NUM> and commissure points <NUM>. The valve assembly <NUM> may be wholly or partly formed of any suitable biological material or polymer. Examples of biological materials suitable for the valve assembly <NUM> include, but are not limited to, porcine or bovine pericardial tissue. Examples of polymers suitable for the valve assembly <NUM> include, but are not limited to, polyurethane, silicone, PTFE and polyester. In at least some examples, portions of valve assembly <NUM>, the cuff and the suture used may include an ultra-high molecular weight polyethylene.

Although the cuff <NUM> is shown in <FIG> as being disposed on the lumenal or inner surface of the annulus section <NUM>, it is contemplated that the cuff <NUM> may be disposed on the ablumenal or outer surface of annulus section <NUM>, or may cover all or part of either or both of the lumenal and ablumenal surfaces of the annulus section <NUM>. Both the cuff <NUM> and the leaflets <NUM> may be wholly or partly formed of any suitable biological material or polymer, including those, such as PTFE, described above in connection with the prosthetic heart valve <NUM>. Additionally, the cuff <NUM> may be formed from polyurethane copolymers or include ultra-high molecular weight polyethylene.

As is shown in <FIG>, in one example the entirety of the valve assembly <NUM>, including the leaflet commissures, is positioned in the annulus section <NUM> of the stent <NUM>. When opened, the leaflets may extend further into the transition region <NUM> or may be designed such that they remain substantially completely within the annulus region <NUM>. In this embodiment, substantially the entirety of the valve assembly <NUM> is positioned between the proximal end <NUM> of stent <NUM> and the commissure points <NUM>, and none of the valve assembly is positioned between the commissure points <NUM> and the distal end <NUM> of the stent <NUM>.

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

<FIG> is a cross-sectional illustration of the prosthetic heart valve <NUM> having leaflets <NUM> disposed within the native valve annulus <NUM>, taken along line <NUM>-<NUM> shown in <FIG>. As seen in <FIG>, the substantially circular annulus section of the stent <NUM> is disposed within a non-circular native valve annulus <NUM>. At certain locations around the perimeter of the prosthetic heart valve <NUM>, gaps <NUM> form between the heart valve <NUM> and the native valve annulus. Blood flowing through these gaps and around the valve assembly <NUM> of the prosthetic heart valve <NUM> can result in paravalvular leak or regurgitation and other inefficiencies which can reduce cardiac performance. Such improper fitment may be due to suboptimal native valve annulus geometry due, for example, to calcification of the native valve annulus or due to unresected native leaflets.

In accordance with the various embodiments of the present disclosure, stent assemblies for use in a prosthetic heart valve incorporating multiple design concepts of a cuff feature for eliminating paravalvular leakage will be described. As to be described hereinafter in greater detail, one or more members may be coupled to a portion of the stent's cuff and to additional stent features such as the runners <NUM> to position the cuff about the abluminal surface of the stent upon deployment from a delivery device to seal in and around any calcific nodules. Prosthetic heart valves having such a cuff pursuant to the embodiments of the present disclosure decrease delivery system volume and profile of the prosthetic heart valve. The cuff sealing material being coupled to the members is positioned out of the area of most volume providing a low profile prosthetic heart valve. When deployed, the members, such as formed from shape memory materials, relax from their tensioned state and position the cuff sealing material in the sealing region of the prosthetic heart valve to reduce paravalvular leakage. Various embodiments of a prosthetic heart valve including a stent assembly having such a cuff pursuant to the present disclosure will now be described.

Referring to <FIG>, a prosthetic heart valve <NUM> is shown which includes a stent <NUM> provided with a cuff <NUM> at least partially disposed over its luminal surface <NUM> such as shown in <FIG> thereby forming a stent assembly. The cuff <NUM> has an extended cuff portion <NUM> which extends outwardly beyond the proximal end <NUM> of the stent coupled to at least one member <NUM> shown under tension. In the embodiment being described, the distance between the proximal end <NUM> of the stent <NUM> and the proximal end <NUM> of the extended cuff portion <NUM> may be in one example about <NUM> as designated by dimension A. As will be understood from the various embodiments of the disclosure to be described, dimension A can be varied depending upon the desired position of the extended cuff portion <NUM> when positioned by the members <NUM>. The cuff <NUM> and extended cuff portion <NUM> may be one integral unitary member, or two or more members sutured together. In either case, they may be formed from a variety of materials as previously described with respect to cuff <NUM>, including, but not limited to bovine/porcine tissue (glycerol impregnated or freeze dried), radiopaque fabric/tissue, braided or weaved fabric (PTFE, PET, UHMWPE), PTFE or gel/collagen coated fabric, multi-layered composite/sheets of any of these materials (e.g., fabric/tissue composites), etc..

The extended cuff portion <NUM> may be coupled to the stent <NUM> by a plurality of circumferentially arranged elongated members <NUM> positioned around the stent, and in particular, between the cuff and the stent to reduce stent volume or bulk. The distal end <NUM> of the members <NUM> may be attached to the runners <NUM> of the stent <NUM> between the cuff <NUM> and the stent frame using known suturing techniques. The proximal end <NUM> of the members <NUM> and the proximal end <NUM> of the extended cuff portion <NUM> may be coupled to a ring shaped hollow tube <NUM> which defines a lumen <NUM>. The hollow tube <NUM> can be constructed as a fabric tube from the same or different materials as the cuff <NUM> described above. The members <NUM> may be sutured to the hollow tube <NUM> using known suturing techniques, by way of example, using a single knotted stitch, followed by a double knot as known in the surgical field. On the other hand, the extended cuff portion <NUM> may be coupled to the hollow tube <NUM> using a running whip stitch as known in the surgical field.

The members <NUM>, in accordance with the present disclosure, have dimensional and/or shape memory properties, which after being tensioned, will return to their original dimensions and/or shape after the tensioning force is removed, i.e., relaxed state. Suitable materials for the members <NUM> may comprise, by way of example, synthetic polymer material such as polypropylene and elastic silicones; natural rubber, super-elastic material, and elastic metals; and shape memory material and shape memory alloys such as Nitinol. The members <NUM> may be in accordance with one embodiment in the nature of an elongated rectangular strip such as an elastic band wherein the members may be placed under tension by elongating from their relaxed or original state. In other embodiments, the members <NUM> may be configured as elements which return to their original dimension and/or shape after a tension force is removed such as springs, e.g., coiled springs and the like. Upon release of the tension, the members will revert to their original length dimension and/or shape. In the embodiment described thus far with respect to <FIG>, the members <NUM> may be in the nature of bands of elastic material about <NUM> in width and about <NUM> in length when relaxed. In accordance with other embodiments, the members <NUM> may be in the nature of coiled springs of biocompatible material or shape memory material such as Nitinol. Accordingly, the members may have different forms and different material properties and characteristics to allowing tensioning and return to their original dimensions and/or shape after the tension force is removed.

In the embodiment shown in <FIG>, the distal end <NUM> of the members <NUM> are attached to the nine runners <NUM> provided circumferentially about the stent <NUM> adjacent the stent's proximal end using any suitable technique, such as suturing and the like. However, the members <NUM> may also be attached to the stent's joints, struts or any other valve or stent feature. As best shown in <FIG>, the runners <NUM> are located between adjacent cells forming the first proximal row of the stent frame <NUM>. In the event of a greater number of cells and runners, it is contemplated that there will be a corresponding increase in the number of members <NUM> used for coupling the extended cuff portion <NUM> to the stent, although not a requirement of the disclosure. It is therefore not required that a member <NUM> be attached to each of the runners <NUM> or other attachment features on the stent <NUM>. In particular, the number of members <NUM> may be less than the number of runners or other such features to which the members could be attached. In addition, it is not required that the members <NUM> be attached symmetrical about the stent <NUM>, rather, the members can be attached asymmetrical about the stent and at different distances between the distal and proximal ends of the stent.

The members <NUM> as shown in <FIG> have been tensioned thereby positioning a portion of the extended cuff portion <NUM> outwardly of the proximal end <NUM> of the stent <NUM>. This initial configuration produces a low profile stent as the extended cuff portion <NUM> (which will form the cuff seal) and members <NUM> are generally positioned within the lumen <NUM> formed by the stent frame as opposed to being supported externally on the abluminal surface <NUM> of the stent. The extended cuff portion <NUM> and members <NUM> can be pulled-up, twisted-up, folded-up, rotated-up, inverted-up and the like into the lumen <NUM> prior to positioning the stent <NUM> in the catheter of the delivery device. When being deployed from the delivery device, the members <NUM> will transform the shape of the extended cuff portion <NUM> from one of its aforementioned shapes into the final shape of the cuff seal as shown in the various embodiments of the disclosure. By way of one example, by pulling on and inverting the extended cuff portion from its delivery configuration or shape to its deployed configuration or shape thereby forming the cuff seal.

In the orientation disclosed in <FIG>, the low profile stent <NUM> can be inserted, typically after being collapsed, into the lumen of a catheter delivery device for delivery to a native aortic valve using known surgical procedures and delivery devices. Upon removal from the delivery device, the members <NUM> will relax to their original non-tensioned state. As a result, the members <NUM> will pull the extended cuff portion <NUM> and the hollow tube <NUM> out of the lumen <NUM> and then over the stent's proximal edge towards the distal end of the stent. At least a portion of the extended cuff portion <NUM> and hollow tube <NUM> will now be disposed over the lower abluminal surface <NUM> of the stent adjacent the stent's proximal edge. By attaching the members <NUM> to the runners <NUM> adjacent the proximal end of the stent <NUM>, the extended cuff portion <NUM> and hollow tube <NUM> are pulled upwardly over the proximal edge of the stent into an undulating cuff seal <NUM>. The undulating pattern is provided by the bottom row of cells <NUM> forming the stent <NUM> which are open facing proximally as shown in <FIG>. Accordingly, the extended cuff portion <NUM> and hollow tube <NUM> conform to the shape of the bottom most rows of cells <NUM> in the stent <NUM>. The extended cuff portion <NUM> extends outwardly of the abluminal surface <NUM> of the stent for engagement with patient's tissue to form a seal thereat, thereby preventing paravalvular leakage.

Referring to <FIG>, another embodiment of a prosthetic heart valve <NUM> including a stent <NUM> having a cuff forming a stent assembly is disclosed. The prosthetic heart valve <NUM> is of similar construction to the prosthetic heart valve <NUM> disclosed in <FIG>. In the prosthetic heart valve <NUM> of <FIG>, the distal end <NUM> of the members <NUM> are attached to the runners <NUM> at the mid-peak or mid-joint of the stent <NUM>. In addition, the extended cuff portion <NUM> extends a greater distance beyond the proximal end <NUM> of the stent <NUM> then in the prosthetic heart valve <NUM> of <FIG>. In accordance with this embodiment, the dimension A may be approximately <NUM>, i.e., the distance between the proximal end <NUM> of the stent <NUM> and the proximal end <NUM> of the extended cuff portion <NUM>. It is contemplated that at the members <NUM> will therefore be larger than those described in <FIG>, for example, about <NUM> wide and about <NUM> long.

In <FIG>, the members <NUM> are shown under tension by being elongated thereby displacing the proximal end <NUM> of the extended cuff portion <NUM> outwardly from the proximal end <NUM> of the stent <NUM>. The members <NUM> and extended cuff portion <NUM> are now configured to be generally confined within the lumen <NUM> of the stent upon insertion into a catheter of a delivery device. At the location of delivery of the prosthetic heart valve <NUM>, the members <NUM> relax thereby pulling the extended cuff portion <NUM> and hollow tube <NUM> out of the lumen <NUM> and then in a direction towards the distal end of the stent. As a result, a portion of the extended cuff portion <NUM> is arranged overlying and circumscribing the abluminal surface <NUM> of the stent as shown in <FIG>. As the members <NUM> are attached to runners <NUM> at the mid-peak or mid-joint of the stent, i.e., distally displaced further away from the runners as shown in the embodiment of <FIG>, the extended cuff portion <NUM> and hollow tube <NUM> form a gathered ring of cuff sealing material <NUM> circumscribing adjacent the proximal end <NUM> of the stent <NUM>, generally lacking the previous undulating pattern.

Referring to <FIG>, the prosthetic heart valve <NUM> is shown being prepared to be received within a catheter of a delivery device. The extended cuff portion <NUM> is pulled against the resistance of the members <NUM> from their relaxed orientation (<FIG>) in an outwardly proximal direction around the stent to place the members <NUM> under tension, as shown in <FIG>. The extended cuff portion <NUM> is then finally positioned within the lumen <NUM> to reduce bulk volume during sheathing of the stent. In <FIG>, the prosthetic heart valve <NUM> is shown after deployment from the delivery device where the members <NUM> have relaxed with the extended cuff portion <NUM> and hollow tube <NUM> arranged circumscribing the proximal end of the stent <NUM> overlying the abluminal surface <NUM> forming the cuff seal <NUM>.

To enhance the sealing effect of the cuff to prevent paravalvular leakage, the hollow tube <NUM> may contain an insert such as filler material or an elongated coiled member. By way of example, as shown in <FIG>, the lumen <NUM> of the hollow tube <NUM> has been filled with expandable material. By way of example, expandable material may include PVA, polyacrilimide, shape memory foam, collagen, and the like to increase sealing bulk. Further, the filler material may include a highly compressible sponge made from alginate cross linked at low temperature. This type of gel will collapse to a large extent when shear forces are applied and return to its original shape when the forces are removed. As a result of the compressibility of this type of material, it will contribute to a low prosthetic heart valve profile, and will spring back when deployed to provide an effective paravalvular leak seal. It is further contemplated that other biocompatible materials can be used for the filler material in accordance with other embodiments of the present disclosure.

As shown in <FIG>, the insert may include an elongated coil member <NUM> or other shaped members formed from various materials such as biocompatible polymers and metals and metal alloys. For example, the coil member <NUM> may be formed of materials similarly used for the construction of the stent <NUM> such as Nitinol which can be collapsed and then returned to its original shape after deployment of the stent.

Referring now to <FIG>, another embodiment of a prosthetic heart valve <NUM> having a stent assembly will be described. As shown in <FIG>, as in the previous embodiments, the prosthetic heart valve <NUM> includes a cuff <NUM> coupled to the stent <NUM> disposed over the luminal surface <NUM> and a plurality of members <NUM> shown under tension thereby forming a stent assembly. The distal ends <NUM> of the members <NUM> are coupled between the cuff <NUM> and stent <NUM> to the runners <NUM> at the stent's mid-joint or mid-peak, circumferentially around the stent using known suturing techniques. The cuff <NUM> is provided with an extended cuff portion <NUM> projecting outwardly from the proximal end <NUM> of the stent <NUM>. By way of one example, the extended cuff portion <NUM> may have a length of approximately <NUM> below the proximal end <NUM> of the stent. In this embodiment, the members <NUM> formed of elastic material may have a width of about <NUM>. and a length of about <NUM>. The proximal end <NUM> of the members <NUM> is sutured to the proximal end <NUM> of the extended cuff portion <NUM> by suitable suturing techniques, such as using a single/double knot on the abluminal side as is known in the surgical field.

As shown in <FIG>, when the members <NUM> are relaxed from their tensioned state as shown in <FIG>, the members recoil and pull the extended cuff portion <NUM> out of the lumen <NUM> and then in a direction towards the distal end of the stent <NUM> over a portion of the abluminal surface <NUM> of the stent. This forms a continuous expandable pocket <NUM> between the extended cuff portion <NUM> and abluminal surface <NUM> of the stent <NUM> about the annulus section <NUM>. The pocket <NUM> is open facing in a distal direction circumscribing the stent <NUM>, while closed facing in a proximal direction. The height of the pocket can be modified by changing the length of the extendable cuff portion <NUM>. The pocket <NUM> receives fluid pressure in the patient's artery when deployed as an aortic valve to expand and seal around calcified nodules.

Referring now to <FIG>, there will be described a prosthetic heart valve <NUM> having a stent assembly in accordance with an exemplary embodiment not falling within the scope of the claims As shown in <FIG>, the members <NUM> under tension have their distal ends <NUM> coupled to the runners <NUM> at the mid-joint or mid-peak of the stent <NUM> between the cuff <NUM> and the stent using suitable suturing techniques thereby reducing the bulk or volume of the stent. The members <NUM> extend outwardly overlying the abluminal surface <NUM> of the stent <NUM> in a proximal direction. The proximal ends <NUM> of the members <NUM> are generally arranged adjacent the proximal end <NUM> of the stent <NUM>.

As previously described, the members <NUM> may be constructive in the nature of elongated bands of elastic material. In the embodiment of <FIG>, the members <NUM> may be approximately <NUM> in width and <NUM> in length. A panel <NUM> of sealing material is arranged overlying the abluminal surface <NUM> of the stent <NUM> adjacent the proximal end <NUM> of the stent. The sealing material <NUM> may be in the nature of a rectangular elongated panel circumscribing the stent <NUM>. The sealing material <NUM> can be provided from material similar to cuff <NUM> so as to form a seal to prevent paravalvular leakage when the prosthetic heart valve <NUM> is positioned in a native aortic valve. In this embodiment the panel <NUM> may have a height of about <NUM>.

The distal end <NUM> of the panel of sealing material <NUM> is coupled to runners <NUM> about the circumference of the stent <NUM> using any suitable suturing technique as known in the art. The proximal end <NUM> of the panel of sealing material <NUM> terminates adjacent the proximal end <NUM> of the stent <NUM> and is not attached thereto. Rather, the proximal end <NUM> of the members <NUM> is coupled on the abluminal side to the proximal end <NUM> of the panel of sealing material <NUM> using a single/double knot as is known in the surgical field. In addition, each of the members <NUM> are coupled to the panel of sealing material <NUM> using an alternating running stitch from the distal end <NUM> to the proximal end <NUM> of the sealing material along longitudinal axes of the stent <NUM> while the members are under tension by being elongated.

Referring to <FIG>, when the members <NUM> are relaxed, the relaxed state causes the panel of sealing material <NUM> to fold back upon itself in a direction towards the distal end of the stent over the abluminal surface <NUM> of the stent <NUM> to create a bunched-up ring of sealing material <NUM> at the location of the runner <NUM> to which the distal end <NUM> of the sealing material was attached. The location of the sealing material can be changed by altering the runner attachment location along the stent in the proximal/distal direction.

Although certain embodiments of the prosthetic heart valve having a stent assembly as described herein may provide a single feature for reducing paravalvular leakage, it should be understood that multiple similar or dissimilar features may be utilized on a single prosthetic heart valve to reduce paravalvular leakage. Various embodiments of a low profile prosthetic heart valve have been described in accordance with the present disclosure. In certain embodiments, an extended cuff is coupled to the stent with a plurality of members in the nature of elongated shape memory material such as elastic members or shape memory members, or coiled members to provide a low profile prosthetic heart valve for catheter delivery. The members are initially placed under tension to maintain an extended cuff portion in a first orientation such as outwardly of the proximal end of the stent. Upon relaxing the tension in the members, the extended cuff portion is pulled towards the distal end of the stent over the abluminal surface to form a cuff seal at various locations along the stent in the annulus section. In some embodiments, the cuff seal is in the nature of a circumscribing expandable pocket, the height of which can be modified. Prosthetic heart valves with expandable pockets are described in greater detail in <CIT>. In other embodiments of the present disclosure, a panel of sealing material may be placed circumferentially about the abluminal surface of the stent to which the members are coupled. In the various embodiments, the members remain coupled to the cuff material and stent as an integral component of the prosthetic heart valve when replacing native valves.

A prosthetic heart valve incorporating a stent assembly for replacing a native valve in accordance with one embodiment of the disclosure is constructed from a stent having a luminal surface and an abluminal surface extending between a distal end and a proximal end thereof; a valve may be disposed within the stent; a cuff coupled to the stent having a first orientation and a second orientation; and a plurality of members having a distal end coupled to the stent and a proximal end coupled to the cuff, the plurality of members having a first state when the cuff is arranged in the first orientation and a second state when the cuff is arranged in the second orientation.

In the aforesaid prosthetic heart valve, wherein the plurality of members have a distal end and a proximal end, and wherein the proximal end of the plurality of members are coupled to the cuff at spaced apart circumferential locations around the stent; and/or wherein the stent includes a plurality of runners, and wherein the distal end of the plurality of members are coupled to the runners; and/or wherein the cuff includes a distal end and a proximal end, and wherein the plurality of members include a distal end and a proximal end, and further including a hollow tube coupled to the proximal ends of the cuff and the plurality of members; and/or wherein the hollow tube defines a lumen, and further including an insert disposed within the lumen; and/or wherein the insert comprises at least one of a filler material or an elongated coiled member; and/or wherein the plurality of members are attached to the cuff circumferentially along spaced apart longitudinally extending axes of the stent; and/or wherein at least a portion of the cuff is at least partially positioned outward of the proximal end of the stent when arranged in the first orientation and at least partially disposed on the abluminal surface of the stent when arranged in the second orientation; and/or wherein the members comprise elastic members having a tensioned first state and a relaxed second state.

A prosthetic heart valve incorporating a stent assembly for replacing a native valve in accordance with one embodiment of the disclosure is constructed from a stent having a proximal end and an abluminal surface; a valve may be disposed within the stent; and a cuff coupled to the stent by a plurality of members having a relaxed state and a tensioned state for orienting at least a portion of the cuff at least partially disposed on the abluminal surface when the plurality of members are in a relaxed state.

In the aforesaid prosthetic heart valve, wherein at least a portion of the cuff is arranged at least partially outward of the proximal end of the stent when the plurality of members are in a tensioned state; and/or wherein the stent includes a plurality of runners, and wherein the plurality of members have a distal end and a proximal end, the distal end of the plurality of members is coupled to one of the runners and the proximal end of the plurality of members is coupled to a portion of the cuff; and/or wherein the cuff is at least partially disposed on the abluminal surface of the stent when the plurality of members is in the tensioned state and relaxed state; and/or wherein the plurality of members are attached to the cuff circumferentially along spaced apart longitudinally extending axes of the stent; and/or wherein the cuff includes a distal end and a proximal end, and wherein the plurality of members include a distal end and a proximal end, and further including a hollow tube coupled to the proximal ends of the cuff and the plurality of members, and an insert comprising at least one of a filler material or an elongated coiled member disposed within the hollow tube; and/or wherein the plurality of members comprise elastic members.

A prosthetic heart valve incorporating a stent assembly for replacing a native valve in accordance with one embodiment of the disclosure is constructed from a stent configured to have a collapsed condition and an expanded condition, the stent having a luminal surface and an abluminal surface extending between a distal end and a proximal end thereof; and a valve assembly may be disposed within the stent, the valve assembly including a plurality of leaflets and a cuff having a portion at least partially disposed on the luminal surface of the stent; at least a portion of the cuff having a first orientation extending outwardly of the proximal end of the stent or at least partially disposed on the abluminal surface of the stent, and a second orientation with a portion of the cuff at least partially disposed on the abluminal surface of the stent; and a plurality of elongated elastic members having a distal end coupled to the stent and a proximal end coupled to the cuff at circumferentially spaced apart locations, the plurality of elastic members having a tensioned state when the cuff is arranged in the first orientation and a relaxed state when the cuff is arranged in the second orientation.

In the aforesaid prosthetic heart valve, wherein the stent includes a plurality of runners, and wherein the distal end of the plurality of elastic members are coupled to the runners; and/or wherein the cuff includes a distal end and a proximal end, and wherein the plurality of elastic members include a distal end and a proximal end, and further including a hollow tube coupled to the proximal ends of the cuff and the plurality of elastic members, and an insert comprising at least one of a filler material or an elongated coiled member disposed within the hollow tube; and/or wherein at least a portion of the cuff is at least partially disposed on the abluminal surface of the stent when arranged in the second orientation and at least partially positioned outward of the proximal end of the stent when arranged in the first orientation; and/or wherein the cuff is at least partially disposed on the abluminal surface of the stent when the plurality of elastic members are in the first orientation and second orientation.

A stent assembly for use in replacing a native heart valve in accordance with one embodiment of the disclosure is constructed from a stent; a cuff coupled to the stent having a first orientation and a second orientation; and a plurality of members coupled between the stent and cuff, the members configured to arrange the cuff between the first and second orientations, wherein the members remain coupled to the stent and cuff after replacement of the native valve.

Claim 1:
A stent assembly for use in a prosthetic heart valve for replacing a native valve, comprising:
a stent (<NUM>) having a proximal end (<NUM>), a distal end (<NUM>), a luminal surface (<NUM>) and an abluminal surface (<NUM>); and
a cuff (<NUM>) coupled to the stent and having a first orientation and a second orientation; characterized in that the assembly further comprises:
a plurality of elongated members (<NUM>) coupled between the luminal surface of the stent and cuff when the cuff is in the first and second orientations, wherein the members remain coupled to the stent and cuff after replacement of the native valve, and
wherein the cuff, when in the first orientation, is at least partially disposed over the luminal surface of the stent (<NUM>) and an extended portion (<NUM>) of the cuff (<NUM>) projects outwardly of a proximal end of the stent (<NUM>), the extended portion (<NUM>) being within a profile of the stent to provide a low profile prosthetic heart valve; and
wherein the cuff (<NUM>), when in the second orientation, is at least partially disposed on the abluminal surface (<NUM>) of the stent; and
wherein the plurality of members (<NUM>) are in a tensioned state when the cuff (<NUM>) is in the first orientation and a relaxed state when the cuff is in the second orientation.