Patent Description:
Diseased mitral and tricuspid valves frequently need replacement or repair. The mitral and tricuspid valve leaflets or supporting chordae may degenerate and weaken or the annulus may dilate leading to valve leak. Mitral and tricuspid valve replacement and repair are frequently performed with aid of an annuloplasty ring, used to reduce the diameter of the annulus, or modify the geometry of the annulus in any other way, or aid as a generally supporting structure during the valve replacement or repair procedure. The annuloplasty ring is typically implanted around the annulus of the heart valve.

A problem with prior art annuloplasty implants is to achieve correct positioning at the heart valve and fixate the implant in the correct position. Suturing devices for annuloplasty implants have disadvantages that makes it difficult to suture in the correct position, thereby resulting insufficient suturing strength, and also in a very time-consuming procedure, which increases the risks for the patient. Furthermore, suturing devices are often not sufficiently compact for catheter based procedures. The use of clips for positioning annuloplasty implants is also associated with challenges, in particular when implanting helix rings that are to be positioned on either side of a heart valve. Insufficient fixation of such implant lead to traumatic effects since the fixation structure must ensure the correct position of the device over time. A further problem in the prior art is thus also to achieve a reliable fixation at the annulus of the heart valve. An annuloplasty implant is intended to function for years and years, so it is critical with long term stability in this regard.

<CIT> discloses an annuloplasty implant with first and second supports carrying a flange unit. The flange unit is made of a tube shaped flexible material being passed into the support. The flange unit is secured to the valve tissue to provide a sealing surface between the support and the tissue. The document does not disclose the utilisation of shape-memory material such that it is configured to assume a contracted state having a second pitch distance in the axial direction being shorter than the first pitch distance.

<CIT> discloses a helical anchor which can be expanded by a balloon catheter. The expansion cause barbs of the anchor to engage into a fabric covering of an adjacent turn.

<CIT> discloses an annuloplasty device having first and second loop-shaped supports. A portion of the valve tissue is trapped between the supports. The supports may comprise respective bores for receiving separate fasteners. The fasteners may be threaded or unthreaded pins and may be pushed into position extending through the bores in both supports and the valve tissue therebetween.

The above problems may have dire consequences for the patient and the health care system. Patient risk is increased.

Hence, an improved annuloplasty implant would be advantageous and in particular allowing for avoiding more of the above mentioned problems and compromises, and in particular ensuring secure fixation of the annuloplasty implant, during the implantation phase, and for long-term functioning, in addition to a less complex procedure, and increased patient safety.

Accordingly, examples of the present invention preferably seek to mitigate, alleviate or eliminate one or more deficiencies, disadvantages or issues in the art, such as the above-identified, singly or in any combination by providing a device according to the appended patent claims.

According to a first aspect an annuloplasty implant is provided comprising first and second supports being adapted to be arranged as a coil in a coiled configuration around an axial direction. The first and second supports are adapted to be arranged on opposite sides of native heart valve leaflets of a heart valve. The first support comprises first retention units fixed in relation to an outer surface of the first support and arranged along at least a first retention portion thereof. The second support comprises second retention units fixed in relation to an outer surface of the second support and arranged along at least a second retention portion thereof. The first and second retention portions are curved in the coiled configuration, and the first and second retention units extend from respective first and second retention portions to produce a retention force, in use, at both of said opposite sides.

According to one example a method of repairing a defective heart valve is disclosed. The method comprises directing an implant delivery catheter to form a first curve of the implant delivery catheter around the heart valve at a first side of native heart valve leaflets thereof, forming a second curve of the delivery catheter around the heart valve on a second side of the heart valve leaflets opposite the first side, and ejecting an annuloplasty implant from the delivery catheter while retracting the delivery catheter such that the annuloplasty implant is arranged along the first and second curve on the first and second sides, whereby retention units arranged on the annuloplasty implant are engaged into tissue of the heart valve from both the first side and the second side when the delivery catheter is retracted.

Further examples of the invention are defined in the dependent claims, wherein features for the second aspect are as for the first aspect mutatis mutandis.

Some examples of the disclosure provide for a facilitated positioning of an annuloplasty implant at a heart valve.

Some examples of the disclosure provide for a facilitated fixation of an annuloplasty implant at a heart valve.

Some examples of the disclosure provide for a less time-consuming fixation of an annuloplasty to a target site.

Some examples of the disclosure provide for securing long-term functioning and position of an annuloplasty implant.

Some examples of the disclosure provide for a reduced risk of damaging the anatomy of the heart such as the annulus or the valve leaflets.

Some examples of the disclosure provide for facilitated guidance of an annuloplasty implant to an annulus of a heart valve.

Some examples of the disclosure provide for a more secure implantation of an annuloplasty implant in narrow anatomies.

Some examples of the disclosure provide for avoiding interference of the annuloplasty implant with the chordae of the valve leaflets.

These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which.

This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the teaching of the invention to those skilled in the art.

The following description focuses on an embodiment of the present invention applicable to cardiac valve implants such as annuloplasty rings. However, it will be appreciated that the invention is not limited to this application but may be applied to many other annuloplasty implants and cardiac valve implants including for example replacement valves, and other medical implantable devices.

<FIG> is a schematic illustration of an annuloplasty implant <NUM> comprising first <NUM> and second <NUM> supports being adapted to be arranged as a coil in a coiled configuration around an axial direction <NUM>. The first and second supports <NUM>, <NUM>, are adapted to be arranged on opposite sides of native heart valve leaflets <NUM> of a heart valve, as illustrated in <FIG>. As shown in <FIG>, the first support <NUM> may be arranged on an atrial side of the valve, and the second support <NUM> may be arranged on a ventricular side. The first and second supports <NUM>, <NUM>, are connected to form a coil- or helix shaped ring. The coil extends through the valve opening (dashed line) at a commissure thereof. In the examples of <FIG>, the second support <NUM> forms a complete loop, whereas the first support <NUM> has a reduced length along its periphery, as will be described further below. The implant <NUM> comprises a shape-memory material, so that the implant <NUM> assumes the coiled configuration after having been ejected from a delivery catheter. While in the delivery catheter the implant <NUM> may be stretched in an elongated shape, i.e. as illustrated in <FIG>. Alternatively, the implant <NUM> may be arranged in the coiled configuration when being delivered to the target site, in which case it may be implanted at the target site for example by incision between the ribs or by opening the chest. The present disclosure, and the associated advantages described for the various examples, applies to both such variants of the implant <NUM>. The first support <NUM> comprises first retention units <NUM> fixed in relation to an outer surface <NUM> of the first support <NUM> and arranged along at least a first retention portion <NUM> thereof. The second support <NUM> comprises second retention units <NUM>' fixed in relation to an outer surface <NUM>' of the second support and arranged along at least a second retention portion <NUM>' thereof. The retention units <NUM>, <NUM>', are illustrated in the perspective views of <FIG> and <FIG>, and in the schematic side views of <FIG> of the implant <NUM> when stretched in an elongated shape, as well in cross-sectional views of <FIG>. As seen in <FIG> and <FIG>, the first and second retention portions <NUM>, <NUM>', are curved in the coiled configuration. Hence, the retention units <NUM>, <NUM>', are arranged to extend along the curved shape of the coil- or helix shaped implant <NUM>. The first retention portion <NUM> may be configured to follow the curvature of the annulus of the heart valve, such as the mitral- or tricuspid valve. The second retention portion <NUM>' may be configured to follow the shape of the valve from the ventricular side. The first and second retention units <NUM>, <NUM>', extend from respective first and second retention portions <NUM>, <NUM>', to produce a retention force, in use, at both of said opposite sides of the native heart valve leaflets. Having retention units <NUM>, <NUM>', at both sides of the valve provides for increasing the retention force and the strength by which the annuloplasty implant <NUM> is fixated at the valve. The first retention units <NUM> pierce and anchor into the tissue at a first side of the valve independently of the second retention units <NUM>' which pierce and anchor into the tissue at a second side, opposite the first side. This provides for having the first support <NUM> repositionable relative the second support <NUM> since any interlocking therebetween can be dispensed with. This provides for a facilitated optimization of the position of the first and second supports <NUM>, <NUM>, at opposite sides of the heart valve. The retention units <NUM>, <NUM>', engage the tissue from both of the mentioned sides, creating a strong retention force in the radial direction, i.e. perpendicular to the axial direction <NUM>. The first and second supports <NUM>, <NUM>, pinch the tissue from both sides of the valve, so that the retention units <NUM>, <NUM>', a forced into the tissue. The retention units <NUM>, <NUM>', provides for shaping the annulus as desired even with a reduced pinching force, since the retention units <NUM>, <NUM>', provides for fixating the shape of the annulus in the radial direction because of the mentioned retention force. This provides for a more reliable implantation at the heart valve, both in the short term and in the long term. By having the first and second retention units <NUM>, <NUM>', fixed in relation to a respective outer surface <NUM>, <NUM>', a robust, less complex and more readily implementable fixation mechanism can be provided, since there is no need for e.g. active retention mechanisms that are activated to move relative the outer surface <NUM>, <NUM>. The aforementioned fixed position in relation to the respective outer surface <NUM>, <NUM>', may be construed as having the retention units <NUM>, <NUM>', attached to the first and second supports <NUM>, <NUM>, at a pre-defined position during manufacturing, or integrated with the first and second supports <NUM>, <NUM>, at a pre-defined position during manufacturing. As illustrated in e.g. <FIG>, a plurality of retention units <NUM>, <NUM>', are provided on the respective first and second supports <NUM>, <NUM>. Each individual retention unit <NUM>, <NUM>' may engage or pierce into the tissue with a short distance, for a minimum amount of injury to the tissue. The sum of the retention force and friction created from all the retention units <NUM>, <NUM>', still provides for a strong fixation into the tissue. The scar healing will be quick since each individual retention unit <NUM>, <NUM>', as relatively small dimensions. This provides for a non-traumatic and still secure fixation of the implant <NUM>. Hence, the retention units <NUM>, <NUM>', provides for tissue fixation at multiple points across the implant <NUM> instead of a few, e.g. <NUM> or <NUM> isolated stiches, resulting in reduced forces per fixation point, and no need for bulky stitching device or knotting device. There is further no risk of coronary artery occlusion or coronary sinus perforation. Hence, the implant <NUM> provides for ease of operation, and a less time consuming procedure than stitching.

The first retention units <NUM> extend from the first retention portion <NUM> in a direction towards the second support <NUM>. This allows the first retention units <NUM> to be securely fixed in to the tissue in the direction where the pinching force may be strongest.

Likewise, the second retention units <NUM>' extend from the second retention portion <NUM>' in a direction towards the first support <NUM>, so that the second retention units <NUM>' may engage or pierce into the tissue effectively.

The first and second retention units <NUM>, <NUM>', may extend in opposite directions along the axial direction <NUM>, as illustrated in the example in e.g. <FIG>. the first and second retention units <NUM>, <NUM>', extend from respective retention portions <NUM>, <NUM>', towards eachother, to clamp the tissue therebetween. It is conceivable however that the retention units <NUM>, <NUM>', may extend in different directions. The first retention units <NUM> may for example extend with an angle in a radially outward direction to engage tissue in a direction towards a tissue wall radially outside the annulus.

The first and second supports <NUM>, <NUM>, are separated with a first pitch distance (p<NUM>) in the axial direction <NUM>, in the coiled configuration, as illustrated in <FIG>. The first and/or second support comprise a shape-memory material configured to assume a contracted state having a second pitch distance (p<NUM>) in the axial direction <NUM> being shorter than the first pitch distance (p<NUM>), as illustrated in <FIG>. Thus, the first and second supports <NUM>, <NUM>, may contract along the axial direction due to movement of the shape-memory material. This provides for increasing the force by which the annuloplasty implant <NUM> is fixed at the annuls, and the retention units <NUM>, <NUM>', may engage the tissue with an increased force from both sides of the valve. The annuloplasty implant <NUM> may be arranged at the valve when assuming the first pitch distance (p<NUM>). The shape-memory material may then be activated so that the contracted state is assumed. with the reduced distance (p<NUM>) between the supports <NUM>, <NUM>, and the retention portions <NUM>, <NUM>', thereof.

The shape-memory material is configured to assume the contracted state in response to an activation temperature. For example, the temperature may be increased to an activation temperature, so that the annuloplasty implant assumes the contracted state with a reduced pitch distance (p<NUM>). It is conceivable that the implant <NUM> may be kept at a defined temperature while arranged in a delivery catheter. Subsequently, when the implant <NUM> is exposed to the warm tissue, when being ejected from the delivery catheter, the activation temperature may be reached, so that the first and second supports <NUM>, <NUM> contracts towards eachother and the retention units <NUM>, <NUM>', can be forced into the tissue. A delivery catheter <NUM> is illustrated in <FIG>, <FIG>, which will be described further below.

The implant <NUM> may comprise a shape memory material, such as NiTiNol, or another suitable biocompatible alloy that can be heat-set in defined shapes, in a heat treatment procedure. The shape-memory material may comprise a material having more than one phase, so that the shape of the supports <NUM>, <NUM>, may be actively varied as described above. The shape memory material can be conceived as any material that is able to change shape as desired, in response to outside interaction, for example with an energy source, such as providing heat and/or electromagnetic energy, that can be transferred to the implant to change its shape. It is also conceivable that the shape of the implant can be affected by direct mechanical manipulation of the curvature of the ring-shape of the implant <NUM>, e.g. by transferring a force or torque to the implant <NUM> via a delivery device. Via the various mentioned shape-affecting procedures the implant <NUM> may assume an elongated delivery configuration for advancement in a catheter, an initial shape when positioned in a coiled configuration along the annulus of the valve, and also an activated shape such as the contracted state described above for enhancing the strength of the fixation at an annulus of the heart valve.

The first and second supports <NUM>, <NUM>, are configured to engage with a restraining unit at a separation at the first pitch distance (p<NUM>) and to assume the contracted state upon removal of the restraining unit. This provides for facilitating the positioning of the implant <NUM> at both sides of the valve, since the pitch distance (p<NUM>) may first be increased to avoid undesired friction with the tissue or entanglement with parts of the anatomy. The restraining unit may comprise a delivery catheter <NUM>, which may be positioned around the annulus as described further below with reference to <FIG>, <FIG>, while the first and second supports <NUM>, <NUM>, assumes the curvature of the delivery catheter <NUM> with a first pitch distance (p<NUM>). When the delivery catheter <NUM> is retracted, exposing the annuloplasty implant <NUM>, the first and second supports <NUM>, <NUM>, may contract to the reduced pitch distance (p<NUM>). It is conceivable however that the implant <NUM> may engage with various other restraining units, such as biodegradable elements that allows the implant <NUM> to assume its contracted shape after being biodegraded or in other ways removed.

At least part of the first retention units <NUM> may be displaced in a direction along an annular periphery <NUM> of the coil in relation to at least part of the second retention units <NUM>'. A line <NUM> extending from a first retention unit <NUM>, parallel with the axial direction <NUM>, may thereby intersect the annular periphery <NUM> of the second support <NUM> at a position between two second retention units <NUM>'. <FIG> illustrates the first and second retention units <NUM>, <NUM>', being displaced in relation to eachother, so that the first retention units <NUM> may move towards a position between the second retention units <NUM>' (as illustrated by dashed line <NUM>). This may provide for further increasing the retention strength, while minimizing the risk that the retention units <NUM>, <NUM>', pierce completely through the valve tissue. This risk for complications is thereby reduced.

At least part of the first and second retention units <NUM>, <NUM>', may comprise a shape that tapers in a direction from the respective first and second retention portions <NUM>, <NUM>', as illustrated in the examples of e.g. <FIG>, <FIG>. This may provide for facilitating pushing and/or piercing of the retention units <NUM>, <NUM>', into the tissue, while scars are kept at a minimum. The retention units <NUM>, <NUM>', may comprise other structures configured to engage the tissue, such as barbs, needles etc..

The first support <NUM> may be adapted to be arranged on an atrial side of the heart valve, and the second support <NUM> may be adapted to be arranged on a ventricular side of the heart valve. The first support <NUM> may comprise a first posterior bow <NUM> and the second support <NUM> comprises a second posterior bow <NUM>'. The first and second posterior bows <NUM>, <NUM>', may be adapted to conform to a posterior aspect of the heart valve. The first and second retention units <NUM>, <NUM>, may be arranged on respective first and second posterior bows <NUM>, <NUM>', as illustrated in <FIG>. This provides for avoiding piercing the tissue at an anterior side <NUM> of the annuloplasty implant, which can be associated with a greater risk of complications.

Hence, the first and second posterior bows <NUM>, <NUM>', may be separated by an intermediate anterior portion <NUM>. The first and second retention units <NUM>, <NUM>', may be arranged with an off-set distance <NUM> from the anterior portion <NUM> towards respective first and second posterior bows <NUM>, <NUM>', so that the anterior portion <NUM> may comprise a smooth surface free from retention units <NUM>, <NUM>'. <FIG> also show illustrations of the anterior portion <NUM> positioned between the first and second retention portions <NUM>, <NUM>', when the implant <NUM> is in the elongated stretched state. The off-set distance <NUM> may be varied to optimize the annuloplasty implant to the particular anatomy while ensuring that there is no risk of piercing the tissue at the anterior side of the valve.

The first retention units <NUM> may be formed from the material of the first support <NUM>. This may provide for particularly robust and strong first retention units <NUM>. Similarly, the second retention units <NUM>' may be formed from the material of the second support <NUM>. The first and second supports <NUM>, <NUM>, may be integrated and formed from a continuous piece of material. Hence, the first and second retention units <NUM>, <NUM>', may also be formed from such material. The retention units <NUM>, <NUM>', may be cut from the material of the first and second support <NUM>, <NUM>. <FIG> shows an example where the retention units <NUM>, <NUM>', are cut from the material of the first and second supports <NUM>, <NUM>. <FIG> is a magnified view of <FIG> showing an example of different sections of the implant <NUM>. As mentioned, the first support <NUM> may have the retention units <NUM> extending in a first direction, and the second support <NUM> may have the retention units <NUM>' extending in an opposite direction. An intermediate portion <NUM>, without retention units <NUM>, <NUM>', may be positioned therebetween. <FIG>show examples of the cross-sections of the implant <NUM> at the mentioned sections illustrated in <FIG>, in the case the retention units <NUM>, <NUM>', are formed from the material of the implant <NUM>. <FIG> shows a cross-section of the first support <NUM>, where material has been removed (indicated by arrow <NUM> in the figure) from an initially substantially circular support to create tapered retention units <NUM>. <FIG> corresponds to the cross-section of the intermediate portion <NUM>, and <FIG> shows the cross-section of the second support <NUM> where material has been cut away to form retention units <NUM>' in the opposite direction. The retention units <NUM>, <NUM>', may be cut to form various shapes for optimizing the gripping force into the tissue. The retention units <NUM>, <NUM>', may be formed by different cutting techniques such as milling or laser cutting techniques. It is also conceivable that the retention units <NUM>, <NUM>', are fixed or integrated onto the respective support <NUM>, <NUM>, by other methods, or by being formed from other materials.

The support <NUM>, <NUM>, may be formed from a solid rod or other solid elongated structure, having various cross-sections, such as circular, elliptic, rhombic, triangular, rectangular etc. The support <NUM>, <NUM>, may be formed from a hollow tube, or other hollow structures with the mentioned cross-sections. The support <NUM>, <NUM>, may be formed from a sandwiched laminate material, comprising several layers of different materials, or different layers of the same material. The support <NUM>, <NUM>, may be formed from a stent or a stent-like structure, and/or a braided material. The support <NUM>, <NUM>, may be formed from a braid of different materials braided together, or from a braid of the same material. As mentioned, the support <NUM>, <NUM>, may be formed from NiTinol, or another suitable bio-compatible material. The surfaces of the first and second supports <NUM>, <NUM>, may be provided with other materials and/or treated with different materials and/or structured to enhance resistance to breaking in case the material is repeatedly bent.

The first and second supports <NUM>, <NUM>, may have respective free ends <NUM>, <NUM>', configured to be arranged on opposite sides of the native heart valve leaflets, in the coiled configuration, as illustrated in e.g. <FIG>. The two free ends <NUM>, <NUM>', may be displaced from each other with a peripheral off-set distance <NUM> extending in a coil plane <NUM>, as schematically illustrated in <FIG>. The coil plane <NUM> is substantially parallel to an annular periphery <NUM> of the coil and perpendicular to the axial direction <NUM>. The coil plane <NUM> accordingly corresponds to the plane spanned by the annular periphery <NUM> of the implant <NUM> when assuming the coiled configuration. The peripheral off-set distance <NUM> between the two free ends <NUM>, <NUM>', thus extends substantially perpendicular to the central axis <NUM>. This means that, when the implant <NUM> is positioned in the implanted state, around the annulus of the heart valve, the two free ends will be separated along the plane of the valve. By having such off-set <NUM> in the plane of the valve, the resulting reduced length of the first or second support member <NUM>, <NUM>, will allow for reducing the number of retention units <NUM>, <NUM>', required to securely fixate the implant <NUM> at the valve, while at the same time providing for a sufficient overlap of the first and second support member <NUM>, <NUM>, on the opposites sides of the valve to attain a sufficiently strong pinching effect therebetween to fixate the annulus in a modified shape. In situations, placing retention units <NUM>, <NUM>', on the anterior side may be associated with high risk, as discussed above. This can therefore be avoided, by having the off-set <NUM> as specified. Furthermore, the interference of the implant <NUM> with the movements of the valve will be minimized. Fastening of the implant <NUM> on the atrial side can thus be accomplished by fixation of the posterior bow <NUM>, and there will be no interference on the atrial side with the movement of the valve, due to the off-set distance <NUM> reducing the circle sector of the first support <NUM>.

The off-set distance <NUM> may correspond to a determined circle sector <NUM> of the annular periphery <NUM> by which the two free ends <NUM>, <NUM>', are separated. Hence, the determined circle sector <NUM> may overlap with the anterior portion <NUM> in the coiled configuration. The length of the circle sector <NUM> and the associated distance by which the two free ends <NUM>, <NUM>', are separated may be varied to accommodate various applications and procedures, and be tailored to various anatomies. It is thus possible to provide a highly compliant implant <NUM> with a minimum of interference with the natural movements of the heart, and which can be secured more easily via retention units <NUM>, <NUM>'.

The first retention units <NUM> and/or the second retention units <NUM>' may extend in a longitudinal direction (L), and comprise a distal surface <NUM> forming a tapering shape towards a piercing edge <NUM>, as schematically illustrated in the example of <FIG>. This provides for robust retention units <NUM>, <NUM>', allowing for effective grip into the surrounding tissue. The distal surface <NUM> may extend across the full width (w) of the retention unit <NUM>, <NUM>', so that the piercing edge <NUM> is positioned at the periphery of the width (w) as shown in the example of <FIG>. Alternatively, the retention units <NUM>, <NUM>', may be tapered towards a central piercing edge <NUM> as shown in the example of <FIG>. In this case, the distal surface <NUM> may comprise two oppositely chamfered surfaces being joined along the centrally located piercing edge <NUM>. Alternatively, the retention units <NUM>, <NUM>', may comprise a conically tapering surface that narrows towards a centrally located piercing edge or tip <NUM> like a needle. Turning again to <FIG>, the distal surface <NUM> extends in a plane having a normal axis (N) forming an acute angle (α) with the longitudinal direction (L). This provides for a robust retention unit <NUM>, <NUM>', while facilitating manufacturing thereof.

The first and second supports <NUM>, <NUM>, extend with an elongated shape along an axial direction (A), as schematically illustrated in e.g. <FIG>. The first and second supports <NUM>, <NUM>, are shown in the elongated stretched state, as in <FIG>, for a clearer presentation. The normal axis (N) may be substantially parallel with a plane spanned by the axial direction (A) and the longitudinal direction (L), as schematically illustrated in <FIG>. This allows for arranging the piercing edge <NUM> so it extends transverse to the axial direction (A), and also transverse to a surrounding delivery catheter, when arranged therein, which may be advantageous in some applications when the implant <NUM> is delivered to the annulus. Any risk of wear or damage to the surrounding catheter may be reduced in such case.

The axial direction (A) is perpendicular to a radial direction (R) of the first and second supports <NUM>, <NUM>, as shown in <FIG>. In this example, the normal axis (N) is substantially parallel with a plane spanned by the radial direction (R) and the longitudinal direction (L). This may provide for an enhanced grip in the surrounding tissue when the implant <NUM> is in the coiled shape around the annulus of the heart valve. The direction along which the piercing edge <NUM> extends may thus be aligned with the axial direction (A), which provides for an improved retention force into the tissue, as the tissue strive to move in a direction perpendicular to the axial direction (A) as the heart is beating, and when the implant <NUM> is in the coiled shape. The implant <NUM> may be coiled so that the radial direction (R) is directed from the center of the heart valve towards the annulus. In other situations, the implant <NUM> may be coiled so that the radial direction (R) is directed from the annulus to the center of the heart valve. As shown in the example of <FIG>, the shape of the second retention units <NUM>' may be symmetric with the first retention units <NUM> with respect to the radial direction (R). It should be understood however that in some applications it may be advantageous to have respective vector components of the normal axis (N) along the radial direction (R) of the first and second retention units <NUM>, <NUM>', oppositely directed with respect to the radial direction (R).

The longitudinal direction (L) may extend with an angle (v), such as an acute angle (v), relative a normal axis (N') of a surface <NUM> of the first and/or second supports <NUM>, <NUM>, to which the first retention units <NUM> and/or the second retention units <NUM>' are fixed, as schematically illustrated in <FIG>. Having such angled retention units <NUM>, <NUM>', may provide for a further improved anchoring effect into the tissue and reduce the risk of dislocation between the retention units <NUM>, <NUM>', and the annulus. As in the previously described example, the implant <NUM> may be coiled so that the radial direction (R) is directed from the center of the heart valve towards the annulus. This may provide for further reducing the risk of having the annulus tissue to move relative the implant <NUM> in the radial direction (R) as the heart is beating. In other situations, the implant <NUM> may be coiled so that the radial direction (R) is directed from the annulus to the center of the heart valve. As shown in the example of <FIG>, the shape of the second retention units <NUM>' may be symmetric with the first retention units <NUM> with respect to an axis of symmetry around the radial direction (R). It should be understood however that in some applications it may be advantageous to have respective vector components of the normal axis (N) along the radial direction (R) of the first and second retention units <NUM>, <NUM>', oppositely directed with respect to the radial direction (R).

The first retention units <NUM> and/or the second retention units <NUM>' may be movable relative a normal axis (N') of surface <NUM> of the first and/or second supports <NUM>, <NUM>, to which the first retention units <NUM> and/or the second retention units <NUM>' are fixed. The first retention units <NUM> and/or the second retention units <NUM>' may be movable by being flexible. This provides for e.g. delivering the implant <NUM> in a more compact cross-sectional shape through a catheter, having the retention units <NUM>, <NUM>', deflected with a greater angle relative the normal axis (N'). Then, as the implant <NUM> is ejected from the catheter, the angle may be reduced so that the retention units <NUM>, <NUM>', extend a greater distance from the surface <NUM>, for facilitated piercing into the tissue. The retention units <NUM>, <NUM>', may deflect with an angle (v) towards the radial direction (R) as shown in <FIG>, or with an angle (α) towards the axial direction (A) as shown in <FIG>. The first retention units <NUM> and/or the second retention units <NUM>' may be movable by being formed by a shape memory material which changes shape over time, e.g. when being heated to an activation temperature.

The height (h) of the retention units <NUM>, <NUM>', may be in the range <NUM> - <NUM>, which may provide for a particularly advantageous grip into the tissue, while at the same time allowing for a facilitated delivery of the implant <NUM> from a delivery catheter to the annulus of the heart valve. The first and second retention units <NUM>, <NUM>', may be evenly separated along the length of the respective first and second supports <NUM>, <NUM>. The spacing between adjacent retention units <NUM>, <NUM>', may be in the range <NUM> - <NUM>. The spacing between adjacent retention units <NUM>, <NUM>', may also be in the range <NUM> - <NUM>, which may provide for a particularly advantageous anchoring into the tissue.

A method <NUM> of repairing a defective heart valve is disclosed. The method <NUM> is schematically illustrated in <FIG>, in conjunction with <FIG>and <FIG>. The order in which the steps are described should not be construed as limiting, and it is conceivable that the order of the steps may be varied depending on the particular procedure. The method <NUM> comprises directing <NUM> an implant delivery catheter <NUM> to form <NUM> a first curve <NUM> of the implant delivery catheter <NUM> around the heart valve at a first side of native heart valve leaflets thereof. <FIG> illustrate an example where the delivery catheter <NUM> is first advanced to the ventricular side of the heart, and <FIG> illustrate an example where the delivery catheter <NUM> is initially advanced to the atrial side of the heart. Regardless, the method <NUM> further comprises forming <NUM> a second curve <NUM> of the delivery catheter <NUM> around the heart valve on a second side of the heart valve leaflets, opposite the first side. The described positioning of the delivery catheter <NUM> may be preceded by the positioning of a guide wire (not shown) along corresponding first and second curves <NUM>, <NUM>. Thus, the delivery catheter <NUM> may then be advanced over the guide wire, to assume the first and second curves <NUM>, <NUM>, around the valve on either side of the leaflets thereof. The method <NUM> comprises ejecting <NUM> an annuloplasty implant <NUM> from the delivery catheter <NUM> while retracting <NUM> the delivery catheter <NUM> such that the annuloplasty implant <NUM> is arranged along the first and second curve <NUM>, <NUM>, on the first and second sides. Retention units <NUM>, <NUM>', arranged on the annuloplasty implant <NUM> are thereby engaged <NUM> into tissue of the heart valve from both the first side and the second side when the delivery catheter <NUM> is retracted. This provides for positioning the retention units <NUM>, <NUM>', in the correct position at both sides of the valve, without having the risk of damaging the tissue, which otherwise could be the case if the implant <NUM> and retention units <NUM>, <NUM>', thereof would be exposed to the tissue while positioning the implant. Tearing and undesired puncturing of the tissue is thus avoided. A more reliable and secure positioning of the implant <NUM> at the heart valve <NUM> is thus achieved.

The annuloplasty implant <NUM> may be arranged in the delivery catheter <NUM> along the distal portion of the delivery catheter <NUM> being bent along the first and second curves <NUM>, <NUM>. Hence, the annuloplasty implant <NUM> may be bent along the first and second curves <NUM>, <NUM>, simultaneously with the delivery catheter <NUM>. Alternatively, the annuloplasty implant <NUM> may be advanced into the mentioned distal portion of the delivery catheter <NUM> after the latter has been formed to assume the first and second curves <NUM>, <NUM>, and after retraction of the guide wire from the delivery catheter <NUM>, if a guide wire has been used as described above. Regardless, the annuloplasty implant <NUM> is further ejected out from the distal portion while retracting the delivery catheter <NUM> as explained above and further below with reference to <FIG>, <FIG>. the implant <NUM> remains substantially stationary in the coiled position (defined by the first and second curves <NUM>, <NUM>) with respect to the valve when the delivery catheter <NUM> is retracted. The delivery catheter <NUM> thus defines a path for the implant <NUM> that allows for facilitated positioning thereof without having to navigate the implant <NUM> into the correct position at the valve. This also provides for an atraumatic positioning of the implant <NUM>.

As mentioned, with reference to <FIG>, the first side may be a ventricular side of the heart, and the second side may be the atrial side of the heart. The portions of the delivery catheter <NUM> arranged on the ventricular side are indicated with dashed lines in <FIG>. The first curve <NUM> of the implant delivery catheter <NUM> is arranged around chordae of the heart valve on the ventricular side, and the second curve <NUM> of the delivery catheter <NUM> is arranged along an annulus of the heart valve on the atrial side. The heart valve may be the mitral valve, and the ventricle may thus be the left ventricle. The method <NUM> may comprise positioning the delivery catheter <NUM> in the ventricle by accessing the ventricle through the apex of the heart with an introducer (not shown). The delivery catheter <NUM> may then then be inserted through the introducer. Alternatively, the method <NUM> may comprise positioning the delivery catheter <NUM> in the ventricle by accessing the ventricle through the aortic valve, or by creating access to the left ventricle through the ventricular septum between the right and left ventricle. Regardless, the method <NUM> comprises in this example forming a first curve <NUM> of the implant delivery catheter <NUM> around the chordae of the heart valve on a ventricular side of the heart valve <NUM>. The delivery catheter <NUM> may thus be first navigated to the ventricular space between the chordae and the heart muscle, so that the delivery catheter <NUM> can be curved around the chordae on the ventricular side. The method <NUM> may comprise inserting the implant delivery catheter <NUM> through the heart valve <NUM> to an atrial side thereof, and forming <NUM> a second curve <NUM> of the delivery catheter along an annulus of the heart valve on the atrial side. The delivery catheter <NUM> may be advanced such that annulus is followed in a counter-clockwise direction. In the example of <FIG>, the delivery catheter <NUM> has been inserted through the heart valve <NUM> to form the second curve <NUM> on the atrial side. Parts of the delivery catheter <NUM> on the atrial side has been illustrated with a solid line for clarity of presentation. In <FIG>, the delivery catheter <NUM> has been advanced through the valve <NUM> at the commissure <NUM>, and with a distal tip <NUM> of the delivery catheter <NUM> positioned as illustrated in <FIG>, adjacent the opposite commissure.

The method <NUM> comprises ejecting <NUM> the annuloplasty implant <NUM> from the delivery catheter <NUM> while retracting <NUM> the delivery catheter <NUM> such that the annuloplasty implant <NUM> is arranged along the first and second curve on the ventricular and atrial side. <FIG> illustrates an example where the implant <NUM> has been ejected and the delivery catheter <NUM> has been retracted back from the atrial side, and through the valve, now having the distal tip <NUM> arranged at the ventricular side, ready to release the implant <NUM>. Portions of the implant <NUM> on the atrial side are illustrated with solid lines, and portions of the implant <NUM> on the ventricular side are illustrated with dashed lines. The implant <NUM> is thus abutting the valve tissue on the ventricular and atrial sides of the valve <NUM>. The retention units <NUM>, <NUM>', arranged on the annuloplasty implant <NUM> are thus engaged <NUM> into tissue of the heart valve from both the ventricular side and the atrial side when the delivery catheter <NUM> is retracted. <FIG> shows the retracted delivery catheter <NUM> having released the implant <NUM>. The retention units <NUM>, <NUM>', are not shown in <FIG> for clarity of presentation, but the positions of the retention units <NUM>, <NUM>', in <FIG> corresponds to the illustration in <FIG> in this regard. Since the delivery catheter <NUM> is simultaneously retracted along the curvature of the first and second curve <NUM>, <NUM>, when ejecting the implant <NUM>, the positioning of the implant <NUM> will effectively correspond to withdrawing the delivery catheter <NUM> as a sheath previously covering the implant <NUM> which already is arranged along the curvature provided by the delivery catheter <NUM> when forming the first and second curve <NUM>, <NUM>, thereof. Hence, the delivery catheter <NUM> can effectively serve as a guide for the implant <NUM> for the positioning thereof on the ventricular and atrial side, without having to navigate the implant <NUM> into the correct position after being ejected from the delivery catheter <NUM>. This provides for improving the control of the positioning of the implant <NUM>, since otherwise, as soon as an implant is ejected from a delivery catheter, the amount of control and steerability on the ejected part is diminished by the decoupling from the physical constrain of the catheter. Positioning the implant <NUM> as described above removes the steerability requirement on the implant <NUM> after being ejected, due to the guiding of the implant <NUM> to the final position, while being fully confined within the delivery catheter <NUM>. This also minimizes the risk of interference with the surrounding anatomy, such as entanglement of the implant with the chordae. This also provides for positioning the retention units <NUM>, <NUM>', in the correct position at the valve, without having the risk of damaging the tissue, which otherwise could be the case if the implant <NUM> and retention units <NUM>, <NUM>', thereof would be exposed to the tissue while positioning the implant. Tearing and undesired puncturing of the tissue is thus avoided. A more reliable and secure positioning of the implant <NUM> at the heart valve <NUM> is thus achieved.

As shown in the example of <FIG>, the delivery catheter <NUM> may be initially positioned in the atrium, via access through the atrial septum, and directed to the anterior commissure <NUM>. A first curve <NUM> of the delivery catheter <NUM> is arranged around chordae of the heart valve on the ventricular side, again returning to the anterior commissure <NUM> (<FIG>). A second curve <NUM> of the implant delivery catheter <NUM> is arranged along an annulus of the heart valve on the atrial side. Again, portions of the implant <NUM> on the atrial side are illustrated with solid lines, and portions of the implant <NUM> on the ventricular side are illustrated with dashed lines. As mentioned above, a guide wire (not shown) may be arranged in the shape of the first and second curves <NUM>, <NUM>, before advancing the delivery catheter <NUM> over the guide wire to assume the corresponding shapes on both sides of the valve leaflets. The guide wire and the delivery catheter be initially advanced into the atrium via access through the atrial septum of the heart. <FIG> shows the delivery catheter <NUM> forming the first curve <NUM> around the valve on the ventricular side, and the distal tip <NUM> is positioned on the ventricular side. <FIG> shows the second curve <NUM> formed at least partly around the annulus on the atrial side. <FIG> shows the delivery catheter <NUM> partly retracted (see e.g. new position of distal tip <NUM> on ventricular side), exposing part of a support ring <NUM> of the annuloplasty implant <NUM> on the ventricular side. The retention units <NUM> on the second support ring <NUM> (not shown for clarity of presentation) are thus exposed and can be advanced into the tissue as the delivery catheter <NUM> is gradually retracted. <FIG> shows the annuloplasty implant <NUM> just being fully released from the distal tip <NUM> of the delivery catheter <NUM>, so that first and second supports <NUM>, <NUM>, of the annuloplasty implant <NUM> are arranged to contact opposite sides of the valve. The retention units <NUM>, <NUM>', (not included in the illustrations of <FIG>for clarity of presentation) arranged on the annuloplasty implant <NUM> are thus engaged <NUM> into tissue of the heart valve from both the ventricular side and the atrial side when the delivery catheter <NUM> is retracted, without risk of damaging the tissue, since there is no rotational movement of the implant <NUM> with respect to the tissue. Further, as with the example in <FIG>, the delivery catheter <NUM> can effectively serve as a guide for the implant <NUM> for the positioning thereof on the ventricular and atrial side, without having to navigate the implant <NUM> into the correct position after being ejected from the delivery catheter <NUM>. This provides for improving the control of the positioning of the implant <NUM>. Similarly as described above, a guide wire may be first advanced to assume the first and second curves <NUM>, <NUM>, and the delivery catheter <NUM> may then be advanced over the guide wire to assume a coiled configuration. The guide wire may then be removed, and the implant <NUM> may be inserted into the delivery catheter <NUM>, and thereby guided to assume the coiled configuration of the delivery catheter, which then can be retracted to expose the implant <NUM> which can retain the coiled configuration due to a shape memory of the material thereof.

<FIG> illustrates a further flow chart of a method <NUM> of repairing a defective heart valve. The order in which the steps of the method <NUM> are illustrated should not be construed as limiting and it is conceivable that the order in which the steps of the method <NUM> is carried out may be varied.

In the method <NUM>, the annuloplasty implant <NUM> may be kept substantially stationary in relation to the heart valve <NUM> when being ejected from the delivery catheter <NUM> while simultaneously retracting the delivery catheter <NUM> in relation to the annuloplasty implant <NUM>. As elucidated above, this facilitates positioning of the retention units <NUM>, <NUM>', without risking damaging the tissue.

The annuloplasty implant <NUM> may have a predefined shape having a curvature corresponding substantially to the first and second curve <NUM>, <NUM>, such that, when ejected from the delivery catheter <NUM>, the annuloplasty implant <NUM> is arranged <NUM> along the first and second curve <NUM>, <NUM>, as a coil or helix in a coiled configuration, as illustrated in <FIG>, <FIG>. The first and second curve <NUM>, <NUM>, may thus form two continuously connected loops, on opposite sides of the heart valve, being connected through the commissure <NUM>. This provides for achieving an efficient deployment of an annuloplasty implant <NUM> around the annulus of the valve <NUM>, on both the ventricular and atrial sides.

By having a predefined ring-shape approximating the curvature of the first and second curves <NUM>, <NUM>, of the delivery catheter <NUM>, the annuloplasty implant <NUM> may be readily aligned around the heart valve <NUM> along the extension of the first and second curves <NUM>, <NUM>, when the implant <NUM> is ejected and the delivery catheter is simultaneously withdrawn, with a minimum of movement of the implant <NUM> relative to the valve <NUM> when the delivery catheter <NUM> is withdrawn. A more stable and controlled positioning of the implant <NUM> along the annulus of the heart valve <NUM> may thus be achieved. The predefined ring-shape of the implant <NUM> can be determined for example by a heat treatment procedure during manufacturing of the implant <NUM>. When the implant is confined in the delivery catheter <NUM>, it assumes an elongated configuration, until it is ejected, whereby it assumes the predefined shape, i.e. the relaxed shape of the shape-memory of the material from which the ring is formed. As mentioned above, the implant <NUM> may subsequently also assumed a contracted shape where the distance between supports <NUM>, <NUM>, is further reduced in the axial direction <NUM>, e.g. by the increase of temperature to an activation temperature. This further facilitates fixation of the retention units <NUM>, <NUM>', into the tissue. It is conceivable that the delivery catheter <NUM> is withdrawn gradually to slowly expose the retention units <NUM>, <NUM>', and allow the temperature of the supports <NUM>, <NUM>, to increase, so that the retention units <NUM>, <NUM>' can be gradually pushed into the tissue as the catheter <NUM> is withdrawn. This provides for increasing the control by which the implant is attached at the valve, hence allowing for a safer implantation procedure.

Hence, the method <NUM>, in both examples of <FIG>and <FIG>, a first support ring <NUM> of the coil may be positioned on the atrial side and a second support ring <NUM> of the coil is positioned on the opposite ventricular side when ejecting the annuloplasty implant from the delivery catheter while retracting the delivery catheter, whereby leaflets of the heart valve are pinched between the first and second support rings <NUM>, <NUM>, and the retention units <NUM>, <NUM>', are anchored <NUM> into the tissue.

And the method <NUM> may comprise activating <NUM> a contracted state of the annuloplasty implant <NUM> so that a first pitch distance (p<NUM>) between the first and second support rings <NUM>, <NUM>, is reduced to a second pitch distance (p<NUM>), whereby the first and second support rings <NUM>, <NUM>, move towards eachother so that the retention units <NUM>, <NUM>', are pushed into the tissue.

Claim 1:
An annuloplasty implant (<NUM>) comprising
first (<NUM>) and second (<NUM>) supports being adapted to be arranged as a coil in a coiled configuration around an axial direction (<NUM>), wherein the first and second supports are adapted to be arranged on opposite sides of native heart valve leaflets (<NUM>) of a heart valve,
wherein the first support comprises first retention units (<NUM>) fixed in relation to an outer surface (<NUM>) of the first support and arranged along at least a first retention portion (<NUM>) thereof, the first retention units (<NUM>) being configured to pierce and anchor into tissue at a first side of the heart valve,
wherein the second support comprises second retention units (<NUM>') fixed in relation to an outer surface (<NUM>') of the second support and arranged along at least a second retention portion (<NUM>') thereof, the second retention units (<NUM>') being configured to pierce and anchor into tissue at a second side of the heart valve, opposite the first side
wherein the first and second retention portions are curved in the coiled configuration, and
wherein the first and second retention units extend from respective first and second retention portions to produce a retention force, in use, at both of said opposite sides,
wherein the first and second supports are separated with a first pitch distance (p<NUM>) in the axial direction, in the coiled configuration, and wherein the first and/or second support comprises a shape-memory material configured to assume a contracted state having a second pitch distance (p<NUM>) in the axial direction being shorter than the first pitch distance,
wherein the shape-memory material is configured to assume said contracted state in response to an activation temperature,
wherein the first and second supports are configured to engage with a restraining unit at a separation at the first pitch distance and to assume the contracted state upon removal of the restraining unit, wherein the restraining unit is a delivery catheter.