Patent Description:
Mitral Regurgitation is a valvular dysfunction that causes blood volume to flow during systolic (during left ventricular contraction) from the left ventricle to the left atrium in oppose to a healthy heart where this direction of flow is blocked by the mitral valve. The reverse flow during systolic causes pressure rise in the left atrium. Maintaining a normal cardiac output results in an increased left ventricle pressure.

Treating patients with MR or TR (mitral regurgitation or tricuspid regurgitation) could require valve replacement in order to reduce or eliminate the regurgitation. For many years the acceptable common treatment was surgical repair or replacement of the native valve during open heart surgery. In recent years, a trans vascular technique has been developed for introducing and implanting a prosthetic heart valve using a flexible catheter in a manner that is less invasive than open heart surgery.

In the trans vascular technique, the prosthetic is delivered to the target site (aortic valve, mitral valve, tricuspid valve, or other valve) through a catheter while the device is crimped to a low diameter shaft, and when it is located in the correct position it is expanded/ deployed to the functional size.

The advancing of the catheter to the target site can be through: (a) The vascular system where a catheter is advanced from the femoral vein/ artery, or any other blood vessel that allows access to the to the target site; (b) Trans apical where a catheter is advanced through a small incision made in the chest wall and then through the apex; or (c) Trans atrial where a catheter is advanced through a small incision made in the chest wall and then through the left or right atrium. <CIT> discloses a prosthetic atrioventricular valve for coupling to a native atrioventricular valve. The prosthetic valve includes a support frame and a covering which are shaped to define a downstream skirt. An elongated anchoring member is positioned around the downstream skirt in a subvalvular space. <CIT> discloses a prosthetic valve for replacing an atrioventricular heart valve, said prosthetic valve comprising an annular body on which valvular cusps are fastened. The prosthetic valve is adapted to be inserted into a valve annulus of the heart. The annular body comprises a plurality of anchor elements which are connected thereto on the ventricle side. <CIT> discloses a device for anchoring a prosthetic heart valve to a valve annulus in a heart. The device can include a prosthetic valve with one or more anchors configured to be threaded to secure the device at the native annulus. <CIT> discloses prosthetic mitral valves and devices suitable for deploying said prosthetic mitral valves.

According to an aspect of the invention, there is provided a prosthetic mitral valve assembly, comprising a radially expandable stent including:.

According to another aspect of the invention, there is provided a prosthesis for securing a percutaneously implantable replacement valve in a heart, comprising:.

Optional features of the invention are recited in the dependent claims.

A prosthesis secures a replacement valve in a heart. The prosthesis includes a radially expandable inflow section and outflow section, and migration blocker rods. The inflow section has a tapered shape and is implanted within an atrium of a heart adjacent a native valve annulus. The outflow section couples to the inflow section, and is configured to be implanted through the native valve annulus and at least partially within a ventricle of the heart. The migration blocker rods extend circumferentially around at least a portion of the outflow section and hold native leaflets of the heart valve. In a contracted configuration, the prosthesis may be implanted through a catheter into the heart. In an expanded configuration, the tapered shape of the inflow section in the atrium cooperates with the migration blockers in the ventricle to hold the prosthesis against the native valve annulus.

Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.

When used the singular form "a", "an", "the" refers to one or more than one, unless the context clearly dictates otherwise.

As used herein, the term "includes" means comprise for example, a device that includes or comprises A and B contains A and B but can optionally contain C or other components other than A and B. A device that includes or comprises A and B may contain A or B, or A and B, and optionally one or more other components such as C.

When the words "stent" and "frame" are used they refer to the same element (e.g., see stent <NUM> in <FIG>).

<FIG> shows a short axis section of the four valves in a heart. The aortic valve <NUM>, pulmonary valve <NUM>, tricuspid valve <NUM>, and mitral valve with anterior leaflet <NUM> and posterior leaflet <NUM>. In <FIG>, there is an illustration of the mitral valve with posterior leaflet <NUM> sectioned into P1, P2, P3 and anterior leaflet <NUM> sectioned into A1, A2, and A3. These sectioning methods are common knowledge and acceptable among those skilled in the art. <FIG> also shows a commissure <NUM> between A1 and P1 and a commissure <NUM> is the commissure between A3 and P3.

<FIG> is a three chamber view (long axis) of the heart. In this view, the left atrium <NUM>, left ventricle <NUM>, and right ventricle <NUM> are shown. The aortic valve <NUM> is at the end of the left ventricle outflow tract (LVOT) <NUM>. The mitral valve apparatus with mitral leaflets includes anterior leaflet <NUM> and posterior leaflet <NUM> attached to the chordae tandea <NUM> and papillary muscles <NUM>. This view is a section of the mitral valve through the A2 (shown as area <NUM> in <FIG>) and P2 (shown as area <NUM> in <FIG>) areas of the mitral leaflets.

<FIG> is a two chamber view (long axis) of the heart. In this view the left atrium <NUM> and left ventricle <NUM> are shown. The mitral valve apparatus includes the posterior mitral leaflet <NUM> attached to the chordae tandea <NUM> and papillary muscles <NUM>. This view is a section of the mitral valve through the commissures <NUM> and <NUM> of the mitral leaflets.

<FIG> is a perspective view of a stent <NUM> configured for placement in a native mitral or tricuspid valve. The stent <NUM> in <FIG> is a front view of the stent <NUM> shown in <FIG>. In this embodiment, the stent <NUM> includes an upper section <NUM> (also referred to herein as "inflow section" <NUM>) having an enlarged diameter (circumference) or flared end that tapers into a lower section <NUM> (also referred to herein as "outflow section" <NUM>) of the frame having a reduced diameter (circumference). The upper section <NUM> and/or the lower section <NUM> may have different shape than circular. The stent <NUM> might have any combination of shapes and <FIG> are only examples of the different shapes possible and other may apply as well. Migration blocker rods <NUM> shown in <FIG> are separated rods, which after deployment lean against the native annulus and prevent migration of the stent into the atrium <NUM> shown in <FIG>. The migration blocker rods <NUM> can be in different lengths with different ends and additional features can be added on them, such as: A. leading mechanism to ensure connectivity, after deployment, between different migration blocker rods; B. locking mechanism between the rods; C. barbs to prevent rocking; and D. features that lock the migration blocker rods against the upper section <NUM> of the frame <NUM>.

Inside the stent assembly a prosthetic valve (not shown) might be added. The valve can be either bi-leaflet or tri-leaflet as long as it performs as required and can be made out of any tissue, polymer, or other material, as long as it is biocompatible. The stent <NUM> can be self-expanding stent made of a shape memory material such as, for example, Nitinol. It can be cut of tube, sheet, or/and a pattern that allows crimping and expanding like braided wires or different technique that attaches wires as long as it performs well.

In other embodiments, the stent <NUM> can be a combination of a self-expanding stent and a balloon expandable stent. For example, <FIG> demonstrate an upper section <NUM> including a shape memory alloy that functions as a self-expandable frame, and a lower section <NUM> including a balloon expandable stent that requires balloon inflation for final deployment. The two sections can be attached in any way. For example, welding, mechanical attachment (as shown in <FIG>), and/or additional features that attach them are only some of the ways to attach the two sections of the stent assembly.

The raw material of the stent <NUM> can be metal or any kind that is biocompatible. The stent <NUM> may include a combination of two or more different materials. For example, one part from stainless steel <NUM>/<NUM> and another part from Nitinol. Other materials such as cobalt chrome are only examples, and other materials can be used as well.

The design of the frame <NUM>, either if it is from one part or more, is configured to allow crimping the prosthesis into a low profile shaft (equal or under <NUM> outer diameter (OD)). Patterns that allow this are known and crisscross patterns as shown for example in <FIG> for the outflow section <NUM> or braided stents are two examples and other may be applied as well.

The migration blocker rods <NUM> of the stent <NUM> lean against the native annulus of the tricuspid or mitral valve, in general. When used in the mitral position, the migration blocker rods <NUM> may lean, in specific, against the mitral groove <NUM> shown in <FIG> in the posterior side and against the left fibrous trigon <NUM> and the right fibrous trigon <NUM> in the anterior side shown in <FIG>.

On the atrium side, the flared upper section <NUM> prevents any migration of the stent <NUM> into the ventricle <NUM> or <NUM> shown in <FIG> and helps provide sealing between the stent and the native apparatus by verifying good intimate contact and correlation between the inflow section geometry and the native shape of the mitral annulus and left atrium.

The combination of the migration blocker rods <NUM> from the ventricle side of the native annulus and the upper section <NUM> flared stent from the atrium side of the annulus create a clamping effect on the annulus and provide a positive axial anchoring of the stent <NUM> to its target site.

For the upper section <NUM>, according to certain embodiments, an elliptical shape allows reducing the inflow section projection and therefore reduces the area that faces high pressure during systole. This feature reduces the axial forces that the prosthesis faces and needs to be anchored against. At the same time, an elliptical shape assures continuous contact between the upper section <NUM> and the atrium and prevents any para valvular leakage (PVL). Any other shape that will at the same time prevent PVL and minimize the projection of the inflow is desired.

The curvature that defines the transition zone and/or the inflow section profile may be configured to increase or decrease the clamping effect between migration blocker rods <NUM> and the inflow section <NUM>. <FIG> and <FIG> show two examples and any other curvature that allows the upper section to be fixated in the atrium and the migration blocker rods to stay under the native annulus in the ventricle is acceptable.

In the area of connection between the upper section <NUM> and lower section <NUM> of the stent <NUM> are attached migration blocker rods <NUM> which prevent from the valve from migrating into the left atrium. The migration blocker rods <NUM> go in between the chordae under the native commissures <NUM> and <NUM> shown in <FIG> and leans against the mitral annulus from behind the native leaflets. <FIG>, <FIG>, <FIG>, and <FIG> show the extraction of the migration blocker rods from the stent, passing through the chordae and turning around the native leaflets. At the final position, the rods <NUM> lean against the native annulus.

<FIG> represents different combinations of the inflow and outflow profiles. The inflow profile in the illustrated embodiments can be either circular <NUM> (as shown in <FIG>, <FIG>) or elliptical <NUM> (as shown in <FIG>, <FIG>), or any other shape that fits the native anatomy of the atrium. The outflow profile can be either circular <NUM> (as shown in <FIG>, <FIG>) or elliptical <NUM> (as shown in <FIG>, <FIG>), or any other shape that fits to withhold a prosthetic valve inside, either bi leaflet or tri leaflet. <FIG> illustrate, by way of example, only four combinations out of many possible of the options for the design of the stent <NUM>.

In <FIG>, the circumference of the inflow section <NUM> and its upper end <NUM> can vary between about <NUM> to <NUM>. This large variation is due to the target population of the device, which some have a very large atrium. The circumference of the outflow section <NUM> and its lower end <NUM> can vary between about <NUM> to <NUM>. This variation is to allow different sizes of valves inside the outflow according to the acceptable standards, if they exist, for the mitral and tricuspid position. The height of the stent may vary between about <NUM> to <NUM>, as long as it doesn't injure the left ventricle walls by the lower section <NUM> and lower end <NUM> and doesn't interfere with the flow from the pulmonary veins and/or cause any risk relatively to the left appendage. The valve <NUM> (shown in <FIG>, <FIG>, <FIG>, and <FIG>) can be either bi-leaflet or tri-leaflet as long as it performs as required and can be made out of any tissue, polymer, or other material as long as it is biocompatible. The stent <NUM> can be a self-expanding stent made of a shape memory material such as, for example, Nitinol. It can be cut of tube, sheet, or/and a pattern that allows crimping and expanding like braided wires or a different technique that attaches wires as long as it performs well.

In <FIG> and <FIG>, an illustrated tri leaflet valve <NUM> is mounted in the circular outflow section <NUM>. The valve <NUM> is configured such that the flow of blood goes substantially only in one direction and that substantially no back flow will occur through the valve according to the acceptable standards.

The valve <NUM> can be composed from biological tissue such as pericardium or alternatively from a polymer, fabric, etc..

In other embodiments, such as 5F and <NUM>, the valve <NUM> in the outflow section <NUM> can be bi leaflet.

In <FIG>, there is a front view of the stent <NUM> according to certain embodiments. It is illustrated as an example that the stent <NUM> can have any number of rows of struts (illustrated as "V" shaped structural supports), as long as the struts allow crimping into a catheter and deployment to the final configuration. The outflow section <NUM> can have either <NUM> (one) row of struts or more. In the illustrated embodiments, there is an example of an outflow section <NUM> with <NUM> (one) row of struts in <FIG>, and an embodiment of an outflow section <NUM> with <NUM> (two) rows of struts in <FIG>. This is not limiting and more rows can be added. In certain embodiments, the inflow section <NUM> also includes expandable struts. For example, the inflow section <NUM> may be designed in a similar manner as that of the outflow section <NUM> with a criss-cross pattern and/or any number of rows of struts, as long as the expandable struts allow crimping and expanding of the inflow section <NUM> to its different configurations.

<FIG>, and <FIG> illustrate the migration blocker rods <NUM> from three different views. <FIG> illustrates the migration blocker rods <NUM> in stent <NUM> from a front view, <FIG> illustrates the migration blocker rods <NUM> in stent <NUM> from a side view, and <FIG> illustrates the migration blocker rods <NUM> in stent <NUM> from a bottom view. The rods <NUM> are configured to be attached to the stent <NUM> either to the inflow section <NUM> or to the outflow section <NUM> at the area where these sections are attached to each other, and to provide axial fixation of the stent <NUM> at the target site.

The migration blocker rods <NUM> around the posterior leaflet <NUM> are configured to lean against the mitral groove <NUM> and prevent any migration and axial movement in the posterior side.

The migration blocker rods <NUM> around the anterior leaflet <NUM> are configured to lean against the left and right fibrous trigons <NUM> and <NUM> and prevent any migration and axial movement in the anterior side.

There are one, two, or more migration blocker rods <NUM> around the posterior leaflet <NUM>. There are another one, two, or more migration blocker rods <NUM> around the anterior leaflet <NUM>. The quantity of the migration blockers can vary from two to multiple rods and in the certain illustrated embodiments there are four of them only for visualization and as example. In other embodiments, the quantity of migration blocker rods <NUM> can be any number from two to eighteen.

The migration blocker rods <NUM> can be ended separated from one another, can meet each other behind the leaflets <NUM> and <NUM>, may include a leading mechanism behind the leaflet to ensure the attachment of the rods to one another and may include a locking mechanism that prevents them from separating after deployment.

The migration blocker rods <NUM> can be in different lengths with different ends <NUM> and additional features can be added on them. The end <NUM> of the migration blocker rods <NUM> can be seen in <FIG> and <FIG>. It can be seen that the distance between them can vary from zero, at minimum (they can touch each other), to, at maximum, half the circumference of the outflow section. In the later, the length of the rods <NUM> is very short and the point of leaning against the annulus is under the commissures <NUM> and <NUM> in <FIG>.

In <FIG>, there is a leading mechanism <NUM> at the end <NUM> of the migration blocker rods <NUM> that allows connecting two migration blocker rods <NUM> that come from opposite commissures <NUM> and <NUM>. The leading mechanism <NUM> allows two different migration blocker rods <NUM> to meet and attach to each other. Due to the nature of beating heart procedures and no direct visualization (only through X-ray and ultrasound), it may be useful to have such a mechanism <NUM> that allows leading one rod <NUM> into the other to assure that the two can be connected. The illustrated mechanism <NUM> is only one example but others can be designed and might include wire, suture, metallic, and/or plastic members, etc..

In <FIG>, and <FIG>, there is a snapping mechanism <NUM> at the end <NUM> of the migration blocker rods <NUM> that allows connecting two migration blocker rods <NUM> that come from opposite commissures <NUM> and <NUM> and lock them one into the other. Once two migration blocker rods <NUM> are attached and locked the stent is firmly secured in place and the rods <NUM> can't be crimped back to the crimped configuration unless the snap mechanism <NUM> is released. The snap illustrated in <FIG>, and <FIG> is one example for such mechanism and others with additional members as metallic and/or plastic parts, wire, suture can be added.

<FIG> illustrate migration blocker rods <NUM> that include barbs <NUM> configured to penetrate the mitral annulus from the ventricle side and ensure no relative movement between the frame <NUM> and the mitral annulus. The barbs <NUM> that penetrated the mitral annulus can be locked into the inflow section of the frame from the atrium side or locked into an additional ring. <FIG> is a zoom on the isometric view of a barb that is part of a migration blocker rod <NUM> that penetrated through the annulus into the inflow section <NUM>.

The migration blocker rods <NUM> can be cut from the same tube and heat treated to the final shape. The migration blocker rods <NUM> can be cut from different tube and be attached to the main frame differently using a direct attachment such as welding or with additional members such as sutures, metallic parts, etc. The migration blocker rods <NUM> can be crimped distally to the main frame, proximally to the main frame and on top of it. The migration blocker rods <NUM> might be covered with a fabric, soft tissue, and/or polymer to prevent any damage to the annulus apparatus.

<FIG>, <FIG> illustrate a stent <NUM> that includes two different sections. The inflow section <NUM> is a self-expanding stent made from a shape memory alloy and functions as a self-expandable frame, and the lower section <NUM> is a balloon expandable stent that requires balloon inflation for final deployment.

<FIG> is an isometric view of the two sections attached together through an attachment member <NUM>. The attachment member <NUM> can be part of the inflow section <NUM>, outflow section <NUM>, both the inflow section <NUM> and the outflow section <NUM>, or/and as an additional member.

In <FIG> illustrates an example of an inflow section <NUM> made out of shape memory alloy where the migration blocker rods <NUM> are part of it. For example, inflow section <NUM> and the migration blocker rods <NUM> may be formed from the same piece of shape memory material. In other embodiments of the inflow section <NUM>, the migration blocker rods <NUM> can be omitted, or designed differently. In addition, or in other embodiments of the inflow section <NUM>, an attachment feature for connecting to the outflow section <NUM> can be added. An example of such a feature is a metallic flange that is cut of the frame and illustrated in the attached embodiments as attachment member <NUM>.

<FIG> illustrates an example of an outflow section <NUM> made out of an alloy such as stainless steel (StSt), such as StSt <NUM>/ StSt <NUM>. In other embodiments, the outflow section <NUM> can be made out of self-expandable alloy such as shape memory alloy and might include the migration blocker rods <NUM>. In addition, or in other embodiments of the outflow section <NUM>, an attachment feature for connecting to the inflow section <NUM> can be added. An example of such a feature is a metallic flange that is cut of the frame and illustrated in the attached embodiments as attachment member <NUM>.

Figure illustrates an enlarged view of the attachment feature <NUM> between the inflow section <NUM> and the outflow section <NUM>. In this embodiment, the attachment feature <NUM> includes two metallic flanges. One is part of the inflow section <NUM> and one is part of the outflow section <NUM>. The two flanges can be attached together by snapping one to another, suturing, them together, or any other attachment method.

<FIG> illustrate how the stent <NUM> may be positioned in the mitral valve. In <FIG>, the section of the heart illustrates a two chamber view and the cross-section of the drawing passes through the mitral valve commissures. It can be seen that the stent <NUM> is behind the posterior leaflet <NUM>, the migration blocker rods <NUM> pop out from the commissures <NUM> and <NUM>, and the end <NUM> of the migration blocker rods <NUM> is in the P2 section of the leaflet (area <NUM> in <FIG>). In <FIG>, the section of the heart illustrates a three chamber view and the cross-section of the drawing passes through the A2 and P2 (areas <NUM> and <NUM> in <FIG>) of the native valve. It can be seen that the stent <NUM> is between the posterior leaflet <NUM> and anterior leaflet <NUM>, the migration blocker rods <NUM> pop out from the commissures area, and the end <NUM> of the migration blocker rods <NUM> is located in the posterior side under the mitral groove <NUM> and under the left and right fibrous trigons (<NUM> and <NUM> in <FIG>) in the anterior side.

<FIG> illustrates the stent <NUM> in the mitral valve from a short axis view from the atrial side. The migration blocker rods <NUM> are located in the ventricle side under the mitral leaflets.

<FIG> and <FIG> illustrate an additional feature that can be added to the migration blocker rods <NUM>. The barbs <NUM> are part of the migration blocker rods <NUM> and designed in a way that after deployment they penetrate the mitral annulus and/ or mitral leaflets and anchor the stent to the annulus. The barbs <NUM> can be integral part of the migration blocker rods <NUM> or additional member that is assembled on the barbs. The barbs <NUM> may be configured so that they have an opposite member or feature in the inflow section <NUM> in a way that after crossing the tissue they lock into the inflow section.

<FIG> is an additional illustration that shows how the migration blocker rods <NUM> pass between the chordae tandea <NUM> in the commissures <NUM> and <NUM>.

<FIG> is an additional drawing illustrating how the migration blocker rod <NUM> leans against the mitral groove <NUM> in the posterior side and the left and right fibrous trigons on the anterior side.

<FIG>, <FIG>, <FIG>, and <FIG> show an example of a trans atrial approach for trans catheter implantation in the mitral position. In <FIG> and <FIG>, the catheter is advanced through the left atrium <NUM> and then through the native mitral valve to the left ventricle. The stent <NUM> in this figure is crimped into the catheter shaft <NUM>. The migration blocker rods are as well crimped in the shaft <NUM> and can be crimped distally toward the apex <NUM>, proximally toward the entering point to the left atrium, or on top of the main frame <NUM>. <FIG> shows the deployment of the stent <NUM>. The migration blocker rods <NUM> pass through the chordae <NUM> under the native commissures and circle the native leaflets. The migration blocker rods <NUM> are configured, in certain embodiments, to bypass or encircle the native leaflets without clamping them to the main frame <NUM>. Then, a completion of the deployment results in clamping the native annulus and allowing the rods <NUM> to prevent migration and rocking. <FIG> shows that the catheter <NUM> is withdrawn backwards after completion of the deployment.

<FIG>, <FIG>, and <FIG> show an example of a trans apical approach for trans catheter implantation in the mitral position. In <FIG>, the catheter shaft <NUM> is advanced through the apex <NUM> of the heart and then through the native mitral valve to the left atrium. The stent <NUM> in this figure is crimped into the catheter shaft <NUM>. The migration blocker rods are as well crimped in the shaft and can be crimped distally toward the atrium, proximally toward the entering point to the apex <NUM>, or on top of the main frame <NUM>. <FIG> shows the deployment of the stent <NUM>. The migration blocker rods <NUM> pass through the chordae <NUM> under the native commissures and circle the native leaflets. Then, a completion of the deployment results in clamping the native annulus and allowing the rods <NUM> to prevent migration and rocking. <FIG> shows that the catheter is withdrawn backwards after completion of the deployment.

Claim 1:
A prosthetic mitral valve assembly, comprising:
a radially expandable stent (<NUM>) including:
an upper section (<NUM>) having a tapered shape anatomically configured to fit to a mitral valve annulus within a left atrium (<NUM>) of a heart;
a lower section (<NUM>) coupled to the upper section (<NUM>) and configured to fit within the mitral valve annulus; and
a plurality of migration blocker rods (<NUM>), each migration blocker rod (<NUM>) comprising a first end and a free second end, wherein the first end of each migration blocker rod (<NUM>) is permanently attached where the upper section (<NUM>) joins the lower section (<NUM>), and wherein the second free end of each migration blocker rod (<NUM>) extends circumferentially around at least a portion of the lower section (<NUM>) toward the second free end of another migration blocker rod (<NUM>) and each migration blocker rod (<NUM>) is configured to pass through a chordae under native commissures and to circle native leaflets to prevent axial movement of the stent (<NUM>) with respect to the mitral valve annulus; and
a replacement valve coupled to the stent (<NUM>).