Patent Description:
Human heart valves, which include the aortic, pulmonary, mitral and tricuspid valves, function essentially as one-way valves operating in synchronization with the pumping heart. The valves allow blood to flow downstream, but block blood from flowing upstream. Diseased heart valves exhibit impairments such as narrowing of the valve or regurgitation, which inhibit the valves' ability to control blood flow. Such impairments reduce the heart's blood-pumping efficiency and can be a debilitating and life threatening condition. For example, valve insufficiency can lead to conditions such as heart hypertrophy and dilation of the ventricle. Thus, extensive efforts have been made to develop methods and apparatuses to repair or replace impaired heart valves.

Prostheses exist to correct problems associated with impaired heart valves. For example, mechanical and tissue-based heart valve prostheses can be used to replace impaired native heart valves. More recently, substantial effort has been dedicated to developing replacement heart valves, particularly tissue-based replacement heart valves that can be delivered with less trauma to the patient than through open heart surgery. Replacement valves are being designed to be delivered through minimally invasive procedures and even percutaneous procedures. Such replacement valves often include a tissue-based valve body that is connected to an expandable frame that is then delivered to the native valve's annulus.

Development of prostheses including but not limited to replacement heart valves that can be compacted for delivery and then controllably expanded for controlled placement has proven to be particularly challenging. An additional challenge relates to the ability of such prostheses to be secured relative to intralumenal tissue, e.g., tissue within any body lumen or cavity, in an atraumatic manner. Further challenges arise when trying to controllably deliver and secure such prostheses in a location such as at a native mitral valve.

<CIT> describes a replacement heart valve that includes an expandable frame configured to engage a native valve annulus. A valve body is coupled to the frame. The valve body can include a leaflet portion and possibly a skirt portion. A portion of the frame has a foreshortening portion configured to longitudinally expand when urged to a radially compacted state and longitudinally contract when urged to a radially expanded state. In one embodiment the valve skirt is attached to the frame so that it can adapt to changes in the length of the frame. A delivery device in some embodiments can use one or more coverings, such as sheaths, to controllably release the replacement heart valve at a native heart valve.

<CIT> describes a vascular implant for replacing a native heart valve that comprises a self-expanding stent supporting a valve body having leaflets. The stent preferably comprises an anchoring structure configured to prevent the implant from passing through the valve annulus. For delivery, the implant is compacted within a delivery device and secured at one end. During delivery the implant is partially released from the delivery device, and positioning of the implant is verified prior to full release. The implant can be at least partially re-sheathed and repositioned.

<CIT> describes a replacement heart valve that has an expandable frame configured to engage a native valve annulus and a valve body mounted to the expandable frame. The valve body can have a plurality of valve leaflets configured to open to allow flow in a first direction and engage one another so as to close and prevent flow in a second direction, the second direction being opposite the first direction.

Embodiments of the present disclosure are directed to a prosthesis, such as but not limited to a replacement heart valve. Further embodiments are directed to methods of delivering a prosthesis into a body cavity and/or securing a prosthesis to intralumenal tissue. In some embodiments, a replacement heart valve and methods for delivering a replacement heart valve to a native heart valve, such as a mitral valve, are provided.

In some embodiments a prosthesis can comprise an expandable frame, and a plurality of anchors, for example a plurality of distal anchors and a plurality of proximal anchors. The anchors can extend outwardly from the frame. The frame can be configured to radially expand and contract for deployment within the body cavity. In some embodiments, when the frame is in an expanded configuration, the frame can have a larger cross-sectional dimension in a middle portion of the frame and a smaller cross-sectional dimension in a proximal portion and a distal portion of the frame, wherein the middle portion is between the proximal and distal portions. In some embodiments, at least some of the anchors comprise a loop that forms an atraumatic end of a corresponding anchor.

In some embodiments, a prosthesis can be configured to atraumatically grasp intralumenal tissue when deployed within a body cavity. The prosthesis can comprise an expandable frame comprising a proximal end and a distal end and having a longitudinal axis extending between the proximal end and the distal end. The frame can be configured to radially expand and contract for deployment within the body cavity, wherein when the frame is in an expanded configuration, the frame has a larger cross-sectional dimension in a middle portion of the frame and a smaller cross-sectional dimension in a proximal portion and a distal portion of the frame, wherein the middle portion is between the proximal and distal portions. The prosthesis can also include a plurality of generally distally extending anchors extending from the proximal portion of the frame and configured so that when the frame is in an expanded configuration each distally extending anchor has an end positioned radially outward from the middle portion of the frame. Alternatively or in addition, the prosthesis can include a plurality of generally proximally extending anchors extending from the distal portion of the frame and configured so that when the frame is in an expanded configuration each proximally extending anchor has an end positioned radially outward form the middle portion of the frame and axially spaced from the ends of the distally extending anchors. At least some of the anchors can comprise a loop that forms an atraumatic end of the anchor. The frame can be configured such that radial expansion of the frame causes the ends of the plurality of distally extending anchors and the ends of the plurality of proximally extending anchors to draw closer together.

A prosthesis according to certain embodiments can be configured to atraumatically grasp intralumenal tissue when deployed within a body cavity. The prosthesis can comprise an expandable frame. A plurality of proximal anchors may be connected to the frame so that when the frame is in an expanded configuration an end of each proximal anchor is positioned radially outward from the frame and extends generally distally. Alternatively or in addition, a plurality of distal anchors may be connected to the frame so that when the frame is in an expanded configuration an end of each distal anchor is positioned radially outward from the frame and extends generally proximally. The ends of the distal anchors are axially spaced from the ends of the proximal anchors when the frame is in an expanded configuration. In some embodiments, at least some of the anchors can comprise a looped end.

Alternatively, or in addition, in some embodiments, at least some of the anchors can comprise a loop. Each loop of these later embodiments can comprise first through fourth segments and an arcuate segment. The first and second segments can both extend in a first generally axial direction away from the frame. The third and fourth segments can extend radially outward from the frame in a second direction generally opposite the first direction, the third segment connected to the first segment and the fourth segment connected to the second segment. The arcuate segment can connect the third segment and the fourth segment that forms an atraumatic end of a corresponding anchor. In some embodiments, the frame is configured such that radial expansion of the frame causes the ends of the plurality of proximal anchors and the ends of the plurality of distal anchors to draw closer together.

In some embodiments, a prosthesis can be configured to atraumatically grasp intralumenal tissue when deployed within a body cavity. The prosthesis can comprise an expandable frame and a plurality of anchors, for example a plurality of proximal anchors, and a plurality of distal anchors. The expandable frame can comprise a proximal end and a distal end and having a longitudinal axis extending between the proximal end and the distal end, the frame configured to radially expand and contract for deployment within the body cavity. The plurality of proximal anchors can each connect to the frame so that when the frame is in an expanded configuration an end of each proximal anchor is positioned radially outward from the frame and extends generally distally. The plurality of distal anchors can each connect to the frame so that when the frame is in an expanded configuration an end of each distal anchor is positioned radially outward from the frame and extends generally proximally, wherein the ends of the distal anchors are axially spaced from the ends of the proximal anchors when the frame is in an expanded configuration. At least some of the anchors can comprise a loop. Each of the anchors that comprises a loop can comprise at least a first segment extending in a first generally axial direction away from the frame, and a second segment and a third segment extending radially outward from the frame in a second direction generally opposite the first direction and coming together in an atraumatic end. The frame can be configured such that radial expansion of the frame causes the ends of the plurality of proximal anchors and the ends of the plurality of distal anchors to draw closer together.

According to some embodiments a prosthesis can be configured to atraumatically grasp intralumenal tissue when deployed within a body cavity. The prosthesis can comprise an expandable frame comprising a proximal end and a distal end and having a longitudinal axis extending between the proximal end and the distal end, the frame configured to radially expand and contract for deployment within the body cavity. A plurality of proximal anchors may be connected to the frame so that when the frame is in an expanded configuration an end of each proximal anchor is positioned radially outward from the frame and extends generally distally. Alternatively or in addition, a plurality of distal anchors may be connected to the frame so that when the frame is in an expanded configuration an end of each distal anchor is positioned radially outward from the frame and extends generally proximally. The ends of the distal anchors are axially spaced from the ends of the proximal anchors when the frame is in an expanded configuration. At least some of the anchors can comprise a loop and each loop can comprise first through fourth segments and an arcuate segment. The first and second segments can both extend in a first generally axial direction away from the frame. The third and fourth segments can extend radially outward from the frame in a second direction generally opposite the first direction, the third segment connected to the first segment and the fourth segment connected to the second segment. The arcuate segment can connect the third segment and the fourth segment that forms an atraumatic end of a corresponding anchor. The frame can be configured such that radial expansion of the frame causes the ends of the plurality of proximal anchors and the ends of the plurality of distal anchors to draw closer together.

Methods of delivering a prosthesis and/or securing the prosthesis to intralumenal tissue, and use of a prosthesis to secure to intraluminal tissue, for example as a replacement heart valve to secure to a mitral valve or other annulus, are also provided. In one embodiment, a method of delivering a replacement valve to a native mitral valve can comprise one or more of the following steps. Delivering a replacement valve mounted on a delivery device to the native mitral valve annulus while the replacement valve is in a radially compacted state, the replacement valve comprising a radially expandable frame comprising a proximal end, a distal end, a plurality of distal anchors extending generally proximally from the frame, and a plurality of proximal anchors extending generally distally from the frame. Positioning the replacement valve so that ends of the distal anchors are on a ventricular side of the native leaflets beyond a location where chordae tendineae connect to free ends of the native leaflets. Releasing at least a portion of the replacement valve from the delivery device to thereby expand the distal anchors radially outwardly to a first radial dimension. Moving the ends of the distal anchors toward the ventricular side of the native valve annulus with the distal anchors extending between at least some of the chordae tendineae to provide tension on the chordae tendineae. Further releasing the replacement valve from the delivery device to thereby expand the proximal anchors radially outwardly to a second radial dimension greater than the first radial dimension, wherein the proximal anchors upon further release of the replacement valve from the delivery device move into engagement with tissue on an atrial side of the native valve annulus while the distal anchors provide tension on the chordae tendineae.

These and other features, aspects and advantages are described below with reference to the drawings, which are intended to illustrate but not to limit the invention. In the drawings, like reference characters denote corresponding features consistently throughout similar embodiments.

The present specification and drawings provide aspects and features of the disclosure in the context of several embodiments of prostheses, replacement heart valves, delivery devices and methods that are configured for use in the vasculature of a patient, such as for replacement of natural heart valves in a patient. These embodiments may be discussed in connection with replacing specific valves such as the patient's aortic or mitral valve. However, it is to be understood that the features and concepts discussed herein can be applied to products other than heart valve implants. For example, the controlled positioning, deployment, and securing features described herein can be applied to medical implants, for example other types of expandable prostheses, for use elsewhere in the body, such as within a vein, or the like. In addition, particular features of a valve, delivery device, etc. should not be taken as limiting, and features of any one embodiment discussed herein can be combined with features of other embodiments as desired and when appropriate.

With initial reference to <FIG>, an embodiment of a prosthesis <NUM> is shown. The illustrated prosthesis <NUM> includes a frame <NUM> that may be self-expanding or balloon expandable. The prosthesis may further include a replacement valve that can be designed to replace a damaged or diseased native heart valve such as a mitral valve. The replacement valve is not shown in this embodiment as to more clearly illustrate features of the frame <NUM>, though it will be understood that a replacement valve is not required as part of the prosthesis. In addition, it will be understood that only a front portion of the frame <NUM> is shown for further ease of illustration.

The frame <NUM> can be made of many different materials, but is preferably made from metal. In some embodiments, the frame <NUM> can be made from a shape memory material, such as nitinol. A wire frame or a metal tube can be used to make the frame. The wire frame of a metal tube can be cut or etched to remove all but the desired metal skeleton. In some embodiments a metal tube is laser cut in a repeating pattern to form the frame. <FIG> illustrates the flat cut pattern of the frame shown in <FIG>. The flat pattern can be cut from a metal tube and then the tube can be bent and expanded to the shape shown in <FIG>. The frame <NUM> can further be expanded and/or compressed and/or otherwise worked to have the desired shape or shapes, such as for introduction and implantation.

As shown, the frame when in an expanded configuration, such as in a fully expanded configuration, has a bulbous or slightly bulbous shape, with a middle portion being larger than the proximal <NUM> and distal <NUM> ends. In some embodiments, the inside diameter of the both ends can be the same, or it can be bigger on one end than the other, while still having a middle portion larger than both the proximal and distal ends. In some embodiments, the effective diameter of the distal frame end is smaller than the effective diameter of the middle portion. The bulbous shape of the frame can advantageously allow the frame to engage a native valve annulus or other body cavity, while spacing the inlet and outlet from the heart or vessel wall. This can help reduce undesired contact between the prosthesis and the heart or vessel, such as the ventricular wall of the heart. In other embodiments, the frame may not have a bulbous portion, and can have substantially the same outer dimension along its entire length, or it may have one end larger than the other end. The prosthesis <NUM> and frame <NUM> may be similar to the replacement heart valves and associated frames disclosed in <CIT> and <CIT>, <CIT> and <CIT>.

A number of struts collectively make up the frame <NUM>. <FIG> illustrates the frame in an expanded configuration with a number of longitudinal struts <NUM> and undulating struts <NUM>, with cells defined by the open spaces between the struts. The longitudinal struts may be arranged so that they are parallel or generally or substantially parallel to a longitudinal axis of the frame. The longitudinal axis of the frame may be defined as the central axis that extends through the center of the frame between the proximal <NUM> and distal <NUM> ends. Any number of configurations of struts can be used, such as the rings of undulating struts shown forming chevrons and diamonds, but also ovals, curves, and various other shapes. The illustrated embodiment includes two rings, or rows of chevrons shown in portion <NUM> and two rows of diamond-shaped cells shown in portion <NUM>.

The frame <NUM> has a non-foreshortening portion <NUM> and a foreshortening portion <NUM>. These portions can be defined by the frame <NUM> and the positioning of various types of struts along the frame <NUM>. In <FIG> it can be seen that the longitudinal struts <NUM> span the length of the non-foreshortening portion <NUM>, while undulating struts <NUM> form the foreshortening portion <NUM>. When the frame is radially collapsed or compacted, the struts <NUM> become more parallel with respect to the longitudinal axis of the frame, causing an outer diameter of the frame to decrease and the longitudinal length of the frame to increase in the foreshortening portion <NUM>. As the frame moves from a compacted position to an expanded position, the longitudinal length of the frame can decrease in the foreshortening portion <NUM>. But, the frame length does not substantially change length in the non-foreshortening portion <NUM>.

Foreshortening of the frame <NUM> can be used to engage and secure the prosthesis to intralumenal tissue in a body cavity, for example tissue at or adjacent a native valve, such as a native valve annulus and/or leaflets. Opposing anchors <NUM>, <NUM> can be constructed on the frame <NUM> so that portions of the anchors, such as tips or ends <NUM>, <NUM>, move closer together as the frame foreshortens. As one example, this can allow the anchors <NUM>, <NUM> to grasp tissue on opposite sides of the native mitral annulus to thereby secure the prosthesis at the mitral valve.

The anchors <NUM>, <NUM> and anchor tips <NUM>, <NUM> can be located anywhere along the frame <NUM> just so long as at least one of the anchors is either connected to the foreshortening portion <NUM> or the foreshortening portion is positioned between the anchors so that a portion of the anchors will be move closer together with expansion of the frame. As shown, the anchors <NUM> are connected to the foreshortening portion <NUM>. The foreshortening portion can also be positioned anywhere along the frame, though it is shown towards the distal end <NUM>. In some embodiments, both of the anchor tips <NUM>, <NUM> are located in the foreshortening portion <NUM>. In some embodiments, the foreshortening portion <NUM> may extend the entire length of the frame, such that there is no non-foreshortening portion <NUM>.

Preferably, each of the anchors <NUM>, <NUM> is positioned or extends generally radially outwardly from the frame <NUM> so that the anchor tips <NUM>, <NUM> are generally spaced away or radially outward from the rest of the frame <NUM>. For example, the anchor tips may be located radially outward from the middle portion of the frame, with the tips <NUM> and <NUM> being axially spaced from one another. In some embodiments, all or part of the structure connected to the anchor tip and extending radially from the frame, including one or more rings and/or struts, can be considered part of the anchor. The anchors can include a base located on the anchor on a side opposite the tip. The base can be for example where the anchor begins to extend from or away from the frame <NUM>.

For example, proximal anchors <NUM> are shown having first <NUM> and second <NUM> struts forming a chevron and connected to longitudinal struts <NUM> at a base of the anchor. The first and second struts of the anchor <NUM> are bent at the base so that the anchor <NUM> extends radially outwardly from the frame as it extends generally distally towards the tip <NUM>. The first and second struts can be connected to each other at a radially outward location to form an outwardly extending loop, and in some embodiments, the first and second struts can be joined at a third strut <NUM> that continues to extend outwardly and/or generally distally. Here the third strut <NUM> is a short strut. The anchor also includes an eyelet <NUM>. As illustrated, the eyelet is located at the distal end <NUM>, though the eyelet can be positioned in other locations along the anchor <NUM>. According to the invention, the tips <NUM> of the proximal anchors extend distally and parallel or substantially parallel with the longitudinal axis of the frame, or as illustrated in <FIG>, and not falling under the scope of the claims, the tips <NUM> may extend generally distally but still radially outwardly inclined or at an acute angle relative to the longitudinal axis of the frame.

As another example, the distal anchors <NUM> are shown having looped ends <NUM>. The looped ends can be larger near the tip to form a type of elongated teardrop. In addition, the tips <NUM> may be substantially flat. The looped end may assist the frame in not getting caught up on structures at or near the treatment location. For example, each loop can be configured so that when the frame is deployed in-situ and expands, the movement of each loop from a delivered position to a deployed position can avoids getting caught on the papillary muscles.

Each distal anchor <NUM> is connected to the frame at a base <NUM>. As illustrated in <FIG>, the base of the distal anchor may be at a location where the corners of adjacent cells meet, such that the base is proximal to the distal end <NUM> of the frame. In other embodiments, the base of the distal anchor may be at a distal most corner of a cell, which corresponds to a distal most point on the frame The distal anchors as illustrated extend from the base <NUM> generally distally before bending back around in an arcuate segment where the distal anchor extends generally proximally and radially outwardly from the frame. As shown, the anchors <NUM> may also generally distally and radially inwardly with respect to the frame such that the distal most point on the prosthesis has a smaller inside diameter than where the base <NUM> connects to the frame. The inside diameter at the distal most can be the same or substantially the same as the inside diameter of the proximal end, or may be smaller. The anchor as illustrated is bent around about <NUM> degrees so that the tip <NUM> extends in the opposite, proximal direction, which may be parallel or substantially parallel to the longitudinal axis of the frame. For example, in <FIG> it can be seen that the distal anchors <NUM> are bent further inward such that the ends of the anchors point proximally and are generally parallel with the longitudinal axis of the frame. Alternatively, the tip <NUM> may extend generally proximally but still extend radially outwardly inclined or at an acute angle relative to the longitudinal axis of the frame.

It will be understood that the anchors can have various other configurations, including the various embodiments that follow. In some embodiments, each of the anchors can extend radially outwardly from the frame at an anchor base and terminate at an anchor tip. The anchors can be connected to the frame at one of many different locations including apices, junctions, other parts of struts, etc. The anchors can comprise first, second, third, or more spaced apart bending stages along the length of each anchor. The anchors can also extend either distally or proximally before and/or after one or more of the bending stages. A portion of the anchor may extend with the frame before or after any bending stages.

In the illustrated embodiment of <FIG> there are twelve distal anchors and twelve proximal anchors. In some embodiments there may be <NUM> anchors on one side and <NUM> on the other. Some embodiments may include different numbers of anchors. In addition, the distal and proximal anchors may be aligned so the tips point generally towards each other, or they may be spaced so that the tips point between two tips on the opposite side, as is illustrated in <FIG>.

The anchor tips <NUM> and <NUM> as described above advantageously provide atraumatic surfaces that may be used to grasp intralumenal tissue without causing unnecessary or undesired trauma to tissue. For example, the proximal anchors tips <NUM> and distal anchor tips <NUM> may form flat, substantially flat, curved or other non-sharp surfaces to allow the tips to engage and/or grasp tissue, without necessarily piercing or puncturing through tissue.

<FIG> show prostheses similar to that of <FIG> with two different styles of distal anchors <NUM>. In <FIG>, the looped end <NUM>' of the distal anchor is generally more elliptical with a curved tip as compared to the elongated teardrop shape of looped end <NUM> of <FIG>. Otherwise the shape is substantially the same.

In <FIG>, the distal anchors <NUM> are looped anchors rather than having looped ends. The looped anchor has a first base <NUM> and a second base <NUM> connected to the frame, wherein the first and second bases are at opposite corners of the same cell. Alternatively, the first and second bases may be located at the distal most corners of adjacent cells. The distal anchors <NUM> extends generally distally from the frame at the first base <NUM> but then is bent back around and begins to extend outwardly from the frame in a generally proximal direction. The distal anchor <NUM> then repeats this configuration in reverse towards the second base <NUM> such that the two sides of the looped anchor are mirror images of one another. It will be understood that the looped anchor can have other configurations and that it may not be symmetrical.

As illustrated in <FIG>, the tips <NUM> of the distal anchors are circumferentially aligned with the tips <NUM> of the proximal anchors, though in other embodiments, the tips <NUM> of the distal anchors may be circumferentially staggered between the tips <NUM> of the proximal anchors. In the embodiment of <FIG>, adjacent distal anchors <NUM> are spaced apart by one cell, though in other embodiments, adjacent distal anchors may be provided on adjacent cells. Thus, for example, instead of having six distal anchors and twelve proximal anchors as shown in <FIG>, there may be a <NUM>:<NUM> correspondence between proximal and distal anchors.

The illustrated looped distal anchor of <FIG> is made up of the following segments. The first segment <NUM> extends generally longitudinally with the frame, extending distally or generally distally (e.g., slightly radially inward) with the frame. The strut is then bent so that a second segment <NUM> extends generally parallel with an adjacent undulating strut <NUM>. The strut is then bent so that a third segment <NUM> begins to extend generally longitudinally and distally or generally distally, and then is bent back around to point in generally the opposite direction (e.g., in a proximal direction parallel or generally parallel with the longitudinal axis of the frame). The third segment <NUM> ends in the rounded tip <NUM> and then the anchor strut repeats to form the mirror image. After the third segment <NUM> bends back around to point in generally the opposite direction, in the embodiment illustrated the third segment may first extend radially outward at an acute angle relative to the longitudinal axis before bending into a portion that extends parallel or substantially parallel to the longitudinal axis. The paired third segments <NUM> extend parallel or generally parallel with one another from the second segment to the tip, though they may also move slightly towards or away from each other in some embodiments.

<FIG> show a prosthesis similar to <FIG> that also has looped distal anchors. In this embodiment the first segment <NUM> extends longitudinally in a distal direction from the frame and the strut is bent back on itself to point generally in the opposite (e.g., proximal) direction. The second segment is bent inward before extending parallel or generally parallel with its mirror image on the other side forming a nose and wing configuration similar to the shape of certain bicycle seats.

The proximal anchors <NUM> also have an elongated third strut <NUM>. The proximal anchor <NUM> is shown having first <NUM> and second <NUM> struts forming a chevron and connected to longitudinal struts <NUM> at a base of the anchor. The first and second struts of the anchor <NUM> are bent at the base so that the anchor <NUM> extends radially outwardly from the frame as it extends towards the tip <NUM>. The first and second struts join at a third strut <NUM> that continues to extend outwardly and is then bent such that the tip points distally and extends in a manner parallel or generally parallel with the longitudinal axis of the frame. The proximal anchor may or may not include an eyelet <NUM> along its length. The distal tip of the proximal anchors may have an atraumatic surface, such as an enlarged circular or curved end as illustrated. When the frame is in an expanded configuration, the distal anchors <NUM> have tips <NUM> that are positioned radially outward of the tips <NUM> of the proximal anchors <NUM>. Other embodiments not falling under the scope of the claims may have the tips <NUM> being positioned outward of the tips <NUM>. Such configurations are also possible with the other frames and prostheses described elsewhere herein.

<FIG> illustrated an embodiment similar to the prosthesis of <FIG> with twelve distal anchors instead of six. Because of this change, in one embodiment two anchors share the first segment <NUM> where the anchor base <NUM>, <NUM> is connected to the frame. As illustrated, each of the proximal and distal anchors may be circumferentially aligned with each other, and each of the distal anchors corresponds to one of the cells.

Turning now to <FIG>, prosthesis and frame embodiments are shown similar to that of <FIG>, including various other components of the prosthesis. A prosthesis can include one or more of a valve <NUM>, a skirt <NUM> and a support band <NUM>. The prosthesis can be a replacement heart valve similar to that and including features similar to those disclosed in <CIT>, published as <CIT>; and <CIT>, published as <CIT>.

The valve <NUM> can be a replacement heart valve which includes a plurality of valve leaflets <NUM>. The plurality of valve leaflets <NUM> can function in a manner similar to the natural mitral valve, or to other valves in the vascular system. The plurality of valve leaflets <NUM> can open in a first position and then engage one another to close the valve in a second position. The plurality of valve leaflets <NUM> can be made to function as a one way valve such that flow in one direction opens the valve and flow in a second direction opposite the first direction closes the valve. The replacement heart valve <NUM> can be constructed so as to open naturally with the beating of the heart. For example, the plurality of valve leaflets <NUM> can open during diastole and close during systole.

In some embodiments, the leaflets <NUM> can be coupled to a skirt <NUM>. For example, the proximal ends of the leaflets <NUM> can be connected to a proximal end of the skirt <NUM>.

The skirt <NUM> can be used to at least partially control how fluid flows through and/or around the valve <NUM>. The skirt <NUM> can surround at least a portion of the valve and be connected to the valve leaflets <NUM>. In some embodiments, the skirt <NUM> can form an inner wall connected to and positioned within the frame <NUM>. The skirt <NUM> can also be made to move with the foreshortening portion <NUM> of the frame <NUM>.

The skirt <NUM> can extend the length of the frame <NUM> or it can extend along only part of the length of the frame <NUM>. In some embodiments, the ends of the heart valve <NUM> can coincide with ends of the skirt <NUM>. In addition, one or more of the ends of the frame <NUM> can coincide with the ends of the skirt <NUM>. In the illustrated embodiment of <FIG>, the proximal end of the skirt <NUM> and heart valve <NUM> are sewn together. The skirt <NUM> can not only extend to the distal end of the frame <NUM> but can also extend to the outside of the frame and is shown wrapped around each of the distal anchors <NUM>.

Other shapes and configurations can also be used for the valve <NUM> and skirt <NUM>. In some embodiments, the skirt <NUM> may extend along the length of the leaflets <NUM>, but is not connected to them. In the illustrated embodiments, the skirt <NUM> is attached to the frame <NUM> and the leaflets <NUM> are attached to the skirt <NUM>.

The skirt <NUM> can be constructed in multiple different ways. The skirt <NUM> can be made of knit polyester or another stretchable or flexible fabric. In some embodiments, the skirt <NUM> is made from a material that is more flexible than the valve leaflet material. The distal and/or proximal end of the skirt <NUM> can be straight, curved, or have any other desired configuration. For example, the skirt <NUM> is shown with undulations patterned to generally correspond to the undulations at the distal end <NUM> of the frame <NUM>. It can be seen that the skirt <NUM> wraps around the struts at the distal end. The skirt <NUM> can be formed of one piece or multiple pieces. For example, the skirt <NUM> attached to the valve <NUM> can be one piece and then each distal anchor can be covered by a separate piece of material of the skirt <NUM>. This is illustrated in <FIG> as one of the distal anchors on the back side remains uncovered. In addition, <FIG> shows the distal anchors uncovered. It is to be understood that other configurations of the skirt <NUM> can also be employed. For example, the anchors may remain uncovered, or only a portion may be covered.

Turning now to <FIG>, another embodiment of the skirt <NUM> is shown. Here rather than the skirt <NUM> corresponding to the undulations at the distal end <NUM> of the frame <NUM>, the skirt extends past the frame and is then wrapped around it. Thus, the skirt <NUM> extends from the inside of the frame <NUM> to the outside of the frame. The skirt can extend completely around the frame for <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, or more of the length of the distal anchors. The skirt can also cover the distal anchors <NUM>. In the illustrated embodiment, the skirt is a one piece skirt, but it will be understood that the skirt can be made of multiple pieces.

The skirt <NUM>, and particularly portions that cover the distal anchors <NUM>, can beneficially be used to help prevent leakage of blood flow around the heart valve. In addition, the skirt can encourage tissue in-growth between the skirt and the natural tissue. This may further help to prevent leakage of blood flow around the heart valve.

The prosthesis <NUM> can also include a support band <NUM> as is shown in <FIG>. The support band <NUM> may be placed or positioned around or within the frame <NUM> at the proximal end <NUM>. The support band <NUM> can be used to reinforce and/or constrain the frame <NUM>. The support band <NUM> can help to control the expansion of the frame <NUM> from the compacted to the expanded state. The support band <NUM> can also be used to reduce the amount of motion that occurs at the proximal end <NUM> after the prosthesis <NUM> has been implanted at the mitral heart valve or other location.

In some embodiments, the support band <NUM> may comprise a polyester fabric band. The support band <NUM> may comprise a no-stretch or limited stretch material. Preferably the support band <NUM> is not made of an elastic material or a material known to have high elasticity. In some embodiments, the support band <NUM> is made from a material that is less flexible than the valve skirt material and/or the valve leaflet material. The distal and proximal ends of the support band <NUM> can be straight, curved, undulating with the undulations of frame, or any other desired configuration.

The support band <NUM> can be connected to the valve frame with a plurality of stitches, loops, knots, staples, or other types of connections. In some embodiments, the frame <NUM> can be sandwiched between two sides or layers of the support band <NUM>. Preferably, the support band <NUM> is a single layer positioned within and attached to the frame <NUM> with a plurality of stitches around one or more of the longitudinal and/or undulating struts. In some embodiments, the support band <NUM> can be attached to the proximal end of the valve skirt <NUM>.

Looking now at <FIG> another embodiment of a prosthesis <NUM> not falling under the scope of the claims is shown. <FIG> show a prosthesis similar to that of <FIG> with a different style and configuration of distal anchor <NUM>. In <FIG>, the distal anchors are shorter than and spaced radially inward from the distal anchors of <FIG>. Thus, as illustrated, the distal anchors <NUM> are not positioned as far radially outward as the proximal anchors, and the tips <NUM> may be positioned radially inward of the tips <NUM>. As described further below, such a configuration may be advantageous in positioning and securing the prosthesis in a mitral valve or other body location. As shown particularly in <FIG>, the distal anchors <NUM> may comprise loops as described above, having a curved or arcuate atraumatic tip to minimize damage to body tissue.

<FIG> show an embodiment of a prosthesis where the distal anchors do not comprise loops, but instead comprise single struts each extending distally from the corners where adjacent cells meet. As described with respect to embodiments above, these anchors may first extend distally or generally distally, and may further extend radially inward, before bending around to extend proximally or generally proximally, such as at an acute angle relative to the longitudinal axis of the frame. The tips <NUM> of the anchors may comprise an atraumatic surface, such as a flattened or curved enlarged tip. As illustrated, the tips <NUM> may be circumferentially staggered between tips <NUM> of the proximal anchors <NUM>, as best shown in <FIG> also show the frame <NUM> having a valve <NUM> and skirt <NUM> attached as described above.

In preferred embodiments, any of the prostheses <NUM> described above may be deployed into a heart valve annulus, and positioned when compacted so that the anchor tips <NUM>, <NUM> of the opposing anchors <NUM>, <NUM> are disposed on opposite sides of the native annulus <NUM> as shown in <FIG> and <FIG>. As the replacement heart valve <NUM> is expanded, the opposing anchors are drawn closer together so as to grasp tissue on opposite sides of the native annulus <NUM> and securely hold the replacement heart valve <NUM> in position. As such, the replacement heart valve <NUM> can be held securely in position without requiring a substantial radial force against the native annulus. Because the anchor tips are preferably atraumatic, the grasping or engaging of tissue by the prosthesis minimizes damage to the native tissue. The foreshortening portion <NUM> can be used to move the anchor tips <NUM>, <NUM> closer together as the replacement heart valve <NUM> moves to the expanded position to thereby engage the native valve annulus. The prosthesis can be deployed into a heart valve or otherwise deployed in manners similar to those described with respect to a replacement heart valve in <CIT> and<CIT>.

<FIG> and <FIG> show a schematic representation of the replacement heart valve <NUM> installed in a human heart <NUM>. The heart is shown in cross-section, and represents typical anatomy, including a left atrium <NUM> and left ventricle <NUM>. The left atrium <NUM> and left ventricle <NUM> communicate with one another through a mitral annulus <NUM>. Also shown schematically is a native anterior mitral leaflet <NUM> having chordae tendineae <NUM> that connect a downstream end of the anterior mitral leaflet <NUM> and to the left ventricle <NUM>.

In one preferred embodiment, a method is provided of delivering a replacement valve to a native mitral valve and atraumatically securing the replacement valve relative to the native mitral valve annulus <NUM>. The replacement valve can be mounted on a delivery device and delivered to the native mitral valve annulus while the replacement valve is in a radially compacted state. The replacement valve may be positioned so that the ends or tips of the distal anchors are on a ventricular side of the native leaflets <NUM> beyond a location where chordae tendineae <NUM> connect to free ends of the native leaflets. At least a portion of the replacement valve can be released from the delivery device to thereby expand the distal anchors radially outwardly. At this time the distal anchors may extend between at least some of the chordae. The distal anchors (along with the frame) can be moved toward the ventricular side of the native valve annulus with the distal anchors extending between at least some of the chordae tendineae to provide tension on the chordae tendineae. With tension provided on the chordae tendineae, the replacement valve can be further released from the delivery device to thereby expand the proximal anchors radially outwardly. The proximal anchors upon further release of the replacement valve from the delivery device can move into engagement with tissue on an atrial side of the native valve annulus, such as with the atrial side of the native valve annulus.

The method just described may utilize any of the prostheses herein described, but may be particularly suitable for the prosthesis of <FIG> where the ends of the distal anchors are not positioned as far out radially as the ends of the proximal anchors when the frame is expanded. Thus, the distal anchors may have a suitable length for extending between and providing tension on the chordae tendineae, but need not and may in some embodiments not engage tissue with the tips <NUM>. Thus, in some embodiments the some or all of the distal anchors remain spaced from tissue on the ventricular side of the native valve annulus after delivery and expansion. The interaction between the distal anchors and the chordae tendineae may therefore be sufficient to secure the distal end of the prosthesis, while the engagement of the proximal anchors with tissue on the atrial side of the native valve annulus will help further secure and orient the prosthesis.

Claim 1:
A prosthesis (<NUM>) configured to atraumatically engage intralumenal tissue when deployed within a body cavity, the prosthesis comprising:
a self-expanding, expandable frame (<NUM>) comprising a proximal end and a distal end and having a longitudinal axis extending between the proximal end and the distal end, the frame configured to radially expand and contract for deployment within the body cavity, wherein when the frame is in an expanded configuration, the frame has a bulbous shape with a larger cross-sectional dimension in a middle portion of the frame, a smaller cross-sectional dimension in a proximal portion of the frame, and a smaller cross-sectional dimension in a distal portion of the frame, wherein the middle portion is between the proximal and distal portions;
a plurality of generally distally extending anchors (<NUM>) extending from the proximal portion of the frame and configured so that when the frame is in an expanded configuration, each distally extending anchor has an end (<NUM>) positioned radially outward from the middle portion of the frame, wherein the ends of the distally extending anchors extend distally and parallel or substantially parallel to the longitudinal axis of the frame; and
a plurality of distal anchors (<NUM>) each connected to the frame at a base, wherein when the frame is in the expanded configuration, each of the plurality of distal anchors extends from the base generally distally before extending generally proximally and radially outwardly from the frame,
characterised in that the ends (<NUM>) of the distal anchors are positioned radially outward of the ends (<NUM>) of the plurality of generally distally extending anchors.