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 device comprising first and second support rings being configured to be arranged as a coil in a first configuration around an axial direction, wherein the first and second support rings are configured to be arranged on opposite sides of native heart valve leaflets of a heart valve, a stiffening unit, wherein at least part of the first and second support rings comprises an interior channel configured to receive the stiffening unit, wherein insertion of the stiffening unit into the interior channel increases the stiffness of the first and/or second support rings.

<CIT> discloses an annuloplasty implant comprising first and second supports. The supports have retention units to provide a retention force on either side of the heart valve. The supports may be formed from a solid rod, a hollow tube, or from a stent.

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

Hence, an improved annuloplasty implant or device 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 device, during the implantation phase, and for long-term functioning, in addition to a less complex procedure, and increased patient safety. A related method would also be advantageous.

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 device is provided comprising first and second support rings having a coiled configuration in which the first and second support rings are arranged as a coil around a central axis, wherein the first and second support rings are configured to be arranged on opposite sides of native heart valve leaflets of a heart valve, a stent arranged around at least a portion of the first and/or second support ring, and wherein the stent comprises retention units.

Further examples of the invention are defined in the dependent claims.

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

Some examples of the disclosure provide for a facilitated fixation of an annuloplasty device 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 device.

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 a more secure implantation of an annuloplasty device in narrow anatomies.

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.

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> schematically illustrates an example of an annuloplasty device <NUM> comprising a first support ring <NUM> and second support ring <NUM> which are adapted to be arranged as a coil, i.e. in a helix-shape, in a coiled configuration around a central axis <NUM>, as illustrated in <FIG>. The device <NUM> is arranged in the coiled configuration at least when in a relaxed state of the material from which the device <NUM> is formed, i.e. free from outside forces acting upon the device <NUM>. The coil-shaped device <NUM> has two free ends <NUM>, <NUM>'. The first and second support rings <NUM>, <NUM>, and the respective free ends <NUM>, <NUM>', are configured to be arranged on opposite sides of native heart valve leaflets <NUM> of a heart valve, as illustrated in the side view of <FIG>. As shown in <FIG>, the first support ring <NUM> may be arranged on an atrial side of the heart valve, and the second support ring <NUM> may be arranged on a ventricular side (the second support ring <NUM> is also shown with dashed lines in the top-down view of <FIG>, where the valve leaflets have been omitted). The second support ring <NUM> is illustrated with a dashed line and is in these examples arranged on the ventricular side of the heart valve, whereas the first support ring <NUM> is arranged on the atrial side of the heart valve (shown with solid line in <FIG>). The first support ring <NUM> may thus extend along the annulus of the heart valve on the atrial side. The first and second support rings <NUM>, <NUM>, are connected to form a coil- or helix shaped ring, as an integral continuous ring. The coil extends through the valve opening at a commissure <NUM>, <NUM>', thereof. In the example of <FIG>, the coil extends through commissure denoted as <NUM>', but is should be understood that the annuloplasty device <NUM> may extend through the commissure denoted as <NUM> in other examples. The first and second support rings <NUM>, <NUM>, may thus assume the coiled configuration also when in an implanted state. As explained further below, the device <NUM> may comprise a shape-memory material, so that the device <NUM> re-assumes the coiled configuration after having been delivered from a catheter (not shown) to the target site, after having been temporarily restrained in an elongated configuration of the catheter. The annuloplasty device <NUM>, i.e. annuloplasty implant <NUM>, may comprise a shape memory material, such as NiTiNol, or another suitable biocompatible alloy that can be heat-set in defined shapes, i.e. in a defined relaxed shape in absence of outside acting forces, in a heat treatment procedure. The annuloplasty device <NUM> may pinch the tissue of the valve leaflets <NUM>, between the first and second support rings <NUM>, <NUM>, i.e. with forces acting in parallel with the central axis <NUM>.

The annuloplasty device <NUM> further comprises a stent <NUM>, 105a, 105b, 105c, arranged around at least a portion of the first and/or second support ring <NUM>, <NUM>. <FIG> shows an example where three stents 105a, 105b, 105c, are arranged around portions of the first and second support rings <NUM>, <NUM>. <FIG> are further detailed views of a stent <NUM> configured to be arranged around at least a portion of the first and/or second support ring <NUM>, <NUM>. It should be understood that the annuloplasty device <NUM> may comprise a varying number of stents <NUM> depending on the particular implant site of the annuloplasty device <NUM>. Furthermore, the ratio of the total length of the first and/or second support ring <NUM>, <NUM>, covered by the stent <NUM>, 105a, 105b, 105c, may vary depending on the placement of the annuloplasty device <NUM>. Although reference is made to stent <NUM> in the present disclosure, it should be understood that any of the stents 105a, 105b, 105c, as exemplified in <FIG> may comprise the features as described for stent <NUM> in relation to <FIG>. The lattice or framework of the stent <NUM> may be formed by laser cutting of a tube-shaped material, such as NiTinol or other bio compatible metal alloy and then pushed over the first and/or second support rings <NUM>, <NUM>. The stent <NUM> thus has a hollow interior to accommodate the first and/or second support rings <NUM>, <NUM>. The stent comprises retention units <NUM>, <NUM>', as schematically illustrated in <FIG> and in the detailed views of <FIG>, <FIG>. The retention units <NUM>, <NUM>', are shaped to pierce into tissue at the heart valve. The retention units <NUM>, <NUM>', are fixed in relation to the stent <NUM>, and the stent <NUM> is fixed in relation to the first and/or second support ring <NUM>, <NUM>, on which the stent <NUM> is arranged. Thus, having stents 105a, 105b, 105c, arranged around at least part of the first and/or second support rings <NUM>, <NUM>, provides for anchoring the annuloplasty device <NUM> to the valve tissue with the retention units <NUM>, <NUM>'. The first and/or second support rings <NUM>, <NUM>, are thus provided with a robust anchoring mechanism by utilizing a stent <NUM>, 105a, 105b, 105c, as an intermediate fixation structure for the retention units <NUM>, <NUM>', thereby dispensing with the need to attach any retention structures directly to the first and/or second support rings <NUM>, <NUM>. The stent <NUM> thus provides for increasing the reliability of the anchoring mechanism of the annuloplasty device <NUM> as the number of separate structures needing to be joined together can be reduced, in particular in the example where the retention units <NUM>, <NUM>', are integrated with the stent <NUM> as mentioned below. Long-term reliability of the annuloplasty device <NUM> may thus be improved. The manufacturing of the annuloplasty device <NUM> may thus also be facilitated, as the number of separate elements is minimized. Manufacturing tolerances may thus be easier to comply with and the overall complexity and associated costs may be reduced, providing for a more viable annuloplasty implant <NUM>. Having an annuloplasty device <NUM> with stents <NUM>, 105a, 105b, 105c, and associated retention units <NUM>, <NUM>', also provides for a modular annuloplasty device <NUM> where a core structure of the first and second support rings <NUM>, <NUM>, may be provided with a stents <NUM>, 105a, 105b, 105c, having retention units <NUM>, <NUM>', in varying configurations and shapes depending on the particular application. The annuloplasty device <NUM> may thus be tailored to the particular patient and anatomical circumstances more easily and patient safety can be further improved.

As elucidated above, the retention units <NUM>, <NUM>', may be formed from the material of the stent <NUM>. The retention units <NUM>, <NUM>', may thus be integrated with the stent <NUM>. The detailed view of <FIG> is a schematic example of how retention unit <NUM> is formed as a part of the framework of the stent <NUM>. The retention unit <NUM> may thus be cut as an elongated structure with a free tip <NUM> within the structural framework of the stent <NUM>. In the example of <FIG>, the retention unit <NUM> is surrounded by support elements <NUM> of the stent <NUM>. The examples in <FIG> show support elements <NUM> arranged in a rhombic pattern or closed cells <NUM>, where the retention units <NUM> extend into the void of individual rhombs or cells <NUM> at defined positions along the length of the stent <NUM>. The stent <NUM> may thus comprise a plurality of support elements <NUM> forming a stent framework of closed cells <NUM>, as further schematically illustrated in the examples shown in <FIG>. A first support element 108a of the plurality of support elements <NUM> of a cell <NUM> may be movable as a retention unit <NUM>, <NUM>', along a radial direction (R), perpendicular to a longitudinal direction (L) of the stent <NUM>, as schematically illustrated in <FIG>. The retention unit <NUM> illustrated in <FIG> may thus be part of the support elements <NUM> forming a closed cell <NUM>. <FIG> show the retention unit <NUM>, i.e. the first support element 108a, arranged in a retracted state (p<NUM>) (<FIG>), and expanded state (p<NUM>) (<FIG>), respectively. The retention unit <NUM>, or first support element 108a, may be expanded like a bow-like structure in the radial direction (R) in the expanded state (p<NUM>). The bow-like shape of the first support element 108a may thus be configured to apply a pressure into the valve tissue and increase the retention force of the stent <NUM> at the annulus. The retention unit <NUM>, or first support element 108a, may be folded into an undulated or otherwise curved or folded shape in the retracted state (p<NUM>), as exemplified in <FIG>.

It should be understood the support elements <NUM> may be cut to form varying patterns. Forming the retention units <NUM>, <NUM>', as integrated structures of the framework of the stent <NUM> provides for robust and strong retention units <NUM>, <NUM>', and a minimized risk of dislocations or deformations thereof over time. An overall robust and reliable fixation mechanism of the annuloplasty device <NUM> is thus provided. Manufacturing is also facilitated, as mentioned above, as the number of separate elements of the annuloplasty device <NUM> requiring assembly is minimized. 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 by laser cutting techniques.

The retention units <NUM>, <NUM>', may be heat-set to assume a defined bent shape as schematically illustrated in the example of <FIG> or <FIG>, showing an expanded state (p<NUM>) of the retention unit <NUM>. The expanded state (p<NUM>) may thus correspond to a relaxed state of the retention unit <NUM> where the latter is not acted upon by external forces. The retention unit <NUM> may be bent and heat-treated during manufacturing so that the retention unit <NUM> assumes a defined shape in the expanded state (p<NUM>). The retention unit <NUM> may thus have a bias towards the expanded state (p<NUM>), by striving towards the relaxed expanded state (p<NUM>).

The retention units <NUM>, <NUM>', may thus be resiliently moveable from a retracted state (p<NUM>) to the expanded state (p<NUM>). For example, a force may be applied to the retention unit <NUM> so that it bends and assumes a retracted position or state (p<NUM>), as exemplified in <FIG>, e.g. if a delivery catheter (not shown) applies a compressive force onto the stent <NUM> and the related retention unit <NUM>. As the stent <NUM> is ejected from the delivery catheter, when the annuloplasty device <NUM> is deployed from the delivery catheter, the compressive force is removed and the resilience of the retention unit <NUM> cause it to move towards the expanded state (p<NUM>). This provides for an effective deployment of the retention units <NUM>, <NUM>', as the first and second support rings <NUM>, <NUM>, of the annuloplasty device <NUM> are ejected from the delivery catheter. The retention units <NUM>, <NUM>', can thus expand and pierce into the valve tissue. The cross-section of the annuloplasty device <NUM> may be minimized as the retention units <NUM>, <NUM>', may assume the retracted state (p<NUM>) when positioned inside the delivery catheter. A smaller cross-section provides for a facilitated navigation of the annuloplasty device <NUM> to a target site in the heart. The delivery catheter may also be subject to less abrasion and wear from the retention units <NUM>, <NUM>', as these may assume the retracted state (p<NUM>) inside the delivery catheter, causing less friction between the tip <NUM> and the inside lumen of the delivery catheter. Reduced friction also facilitates moving the annuloplasty device <NUM> along the delivery catheter, requiring less force and improving the amount of control.

Hence, the retention units <NUM>, <NUM>', may be flexible to bend from the expanded state (p<NUM>) to the retracted state (p<NUM>). This allows also for the retention units <NUM>, <NUM>', to flex to the retracted state (p<NUM>) if withdrawing the annuloplasty device <NUM> into a delivery catheter, in case the implantation is aborted or repositioning is needed. The annuloplasty device <NUM> may thus re-assume the compact cross-sectional profile.

In one example the retention units <NUM>, <NUM>', may comprise a shape-memory material, where activation of the shape-memory material causes the retention units <NUM>, <NUM>', to transfer from the retracted state (p<NUM>) to the expanded state (p<NUM>). For example, the shape-memory material may be temperature activated, so that the retention units <NUM>, <NUM>', move towards the expanded state (p<NUM>) when subject to heating to the body temperature. This provides for an advantageous deployment of the retention units <NUM>, <NUM>', in some applications.

The retention units <NUM>, <NUM>', may be aligned essentially flush with an outer diameter (D) of the stent <NUM> in the retracted state (p<NUM>), as schematically illustrated in <FIG> or <FIG>. This provides for a compact cross-sectional profile of the annuloplasty device <NUM> as well as reduced risk of high pressure and abrasion of the retention units <NUM>, <NUM>', against an inner lumen of a delivery catheter.

The stent <NUM> may be radially contractible along a radial direction (R), perpendicular to a longitudinal direction (L) of the stent <NUM>, so that the stent <NUM> exerts a force (F) on the first and/or second support ring <NUM>, <NUM>. The radial (R) and longitudinal direction (L) of the stent <NUM> is schematically indicated in <FIG>. The examples illustrated in <FIG> are cross-sectional views of the annuloplasty device <NUM>, illustrating the stent <NUM> arranged around the first- or second support ring <NUM>, <NUM>, and a retention unit <NUM> in the expanded state (p<NUM>). The stent <NUM> may thus be radially contractible towards the first and/or second support ring <NUM>, <NUM>, thereby exerting a force (F) onto the latter as indicated with arrows F in the illustrations of <FIG>. The stent <NUM> may thus assume a fixed position in relation to the first and/or second support ring <NUM>, <NUM>, as the force (F) creates friction between the stent <NUM> and the first and/or second support ring <NUM>, <NUM>. The framework of the stent <NUM> may thus be cut to allow movement in the radial direction (R), i.e. allowing the support elements <NUM> of the framework to move in relation to eachother, so that the diameter (D) of the stent <NUM> is variable, as further described with reference to <FIG> and 9a-b. The stent <NUM> may be resiliently expandable in the radial direction (R) so that the stent <NUM> may be expanded to a radially stretched state. The stent <NUM> may then strive towards a contracted relaxed state with an inner diameter being less than the inner diameter in the radially stretched state. The inner diameter in the radially stretched state may be denoted ds (see e.g. <FIG>) and may be more or equal to an outer diameter (dr) of first and/or second support ring <NUM>, <NUM>. The stent <NUM> may thus be positioned over the first and/or second support ring <NUM>, <NUM>, when in the radially stretched state. The stent <NUM> will thus strive towards the contracted relaxed state with a reduced inner diameter, and accordingly exert the aforementioned force (F) on the first and/or second support ring <NUM>, <NUM>. This provides for a facilitated fixation of the position of the stent <NUM> in relation to the first and/or second support ring <NUM>, <NUM>. The example in <FIG> shows a cover <NUM> between the stent <NUM> and the first and/or second support ring <NUM>, <NUM>, as described in more detail below. The difference between dr and ds is thus larger in this case.

The stent <NUM> may comprise a shape-memory material in one example. Activation of the shape-memory material may cause the stent <NUM> to contract to a reduced diameter, along the radial direction R, to apply a force (F) on the first and/or second support ring <NUM>, <NUM>. For example, the shape-memory material may be temperature activated, so that the stent <NUM> strives towards a reduced inner diameter when subject to heating to the body temperature. This provides for increasing the force (F) exerted on the first and/or second support ring <NUM>, <NUM>, to attain a secure fixation of the stent <NUM> thereto.

<FIG> and <FIG> show examples of a radially contractible and expandable stent <NUM>. The stent <NUM> may comprise support elements <NUM> configured to be contractible and expandable so that an outer diameter (D<NUM>, D<NUM>) of the stent <NUM> is variable between an expanded diameter (D<NUM>) and a contracted diameter (D<NUM>) while a predefined length (L<NUM>) of the stent <NUM> is essentially maintained. Thus, as the support elements <NUM> undergo a movement and the diameter varies between D<NUM> and D<NUM>, the overall length (L<NUM>) of the stent <NUM> may be fixed. <FIG> and <FIG> show a length L<NUM> of a section of the stent <NUM> but it should be understood that this may correspond to the overall or total length of the stent <NUM> in the longitudinal direction (L). The stent <NUM> thus exhibit limited or no contraction in the longitudinal direction (L) as the diameter (D<NUM>, D<NUM>) varies. The stent <NUM> may be expanded to D<NUM> and positioned on the first and/or second support ring <NUM>, <NUM>, and subsequently retracted to D<NUM> to apply a force radially inwards and thereby fix its position on the first and/or second support ring <NUM>, <NUM>, while undergoing no or insignificant variations in the length (L<NUM>) of the stent <NUM>. This provides for a facilitated and more accurate positioning of the stent <NUM> on the first and/or second support ring <NUM>, <NUM>. The tailoring of the stent <NUM> to first and second support rings <NUM>, <NUM>, of different dimensions is thus facilitated as the position and coverage of the stent <NUM> over the first and/or second support ring <NUM>, <NUM>, can be predicted with improved accuracy.

The support elements <NUM> may have different shapes configured to predominantly allow movement of the overall framework of the stent <NUM> in the radial direction (R), with limited or no movement in the longitudinal direction (L). <FIG> show an example where the support elements <NUM> are curved in S-shapes. The S-shaped support elements <NUM> are stretched when applying a force in the radial direction (R) so that the stent <NUM> assumes the expanded diameter (D<NUM>) in <FIG>. As the external force is released, the S-shaped support elements <NUM> may contract again so that the stent <NUM> may assume the contracted diameter (D<NUM>) in <FIG>. The length L<NUM> of the stent <NUM> is not changed. It should be understood that some movement may occur that could have minor affect on the length (L<NUM>) of the stent <NUM>, but that the movement in the radial direction (R) is significantly larger than the movement in the longitudinal direction (L). The ratio between the movement in the radial direction (R) and the movement in the longitudinal direction (L) may for example be in the range <NUM>:<NUM> to <NUM>:<NUM> for a particularly advantageous and improved fixation of the stent <NUM> on the first and/or second support ring <NUM>, <NUM>. It is conceivable that the support elements <NUM> may be curved in different shapes to allow the radial movement as described, such as C-shapes or Z-shapes.

<FIG> show an example where the support elements <NUM> are curved in bow-shapes. The bow-shaped support elements <NUM>, or the S-shaped support elements <NUM>, may be arranged to form an essentially cylindrical shape of the stent <NUM>. The support elements <NUM> may thus extend generally across a surface of such cylindrical shape. The bow-shaped support elements <NUM> may be stretched when applying a force in the radial direction (R) so that the stent <NUM> may assume the expanded diameter (D<NUM>) in <FIG>. As the external force is released, the bow-shaped support elements <NUM> may contract again so that the stent <NUM> may assume the contracted diameter (D<NUM>) in <FIG>. As described above, there is no or insignificant movement of the stent <NUM> in the longitudinal direction (L) compared to the movement in the radial direction (R).

As exemplified in <FIG> and <FIG>, the support elements <NUM> may comprise an elongated main frame <NUM> extending essentially along the longitudinal direction (L) of the stent <NUM>. The elongated main frame <NUM> may define the aforementioned predefined length (L<NUM>) of the stent <NUM>. The elongated main frame <NUM> may thus have an essentially fixed position in the longitudinal direction (L) when the outer diameter of the stent <NUM> varies between the expanded diameter (D<NUM>) and the contracted diameter (D<NUM>). This provides for effectively controlling the length of the stent <NUM> in the longitudinal direction (L).

<FIG> show examples of the stent <NUM> having different support elements <NUM> and retention units <NUM>. <FIG> show an example where the support elements <NUM> are S-shaped. The retention units <NUM> may be shaped as expandable bows, as described above, and schematically illustrated in <FIG>. A retracted state (p<NUM>) is shown, as well as an expanded state (p<NUM>) where the bows are illustrated with dashed lines. The retention unit <NUM> may be part of the support elements <NUM> as described in relation to <FIG>. As mentioned, the support elements <NUM> may comprise an elongated main frame <NUM>. In the latter case, the retention unit <NUM> may be part of the elongated main frame <NUM>. <FIG> show an example where the retention units <NUM> may be shaped as expandable prongs or hook-like structures. A retracted state (p<NUM>) is shown, as well as an expanded state (p<NUM>) where the prongs or hook-like structures are illustrated with dashed lines. <FIG> illustrate further examples where the bow-like (<FIG>) or hook-like (<FIG>) retention units <NUM> are arranged on bow-like support elements <NUM> of a stent <NUM>. A retracted state (p<NUM>) is shown, as well as an expanded state (p<NUM>). The retention units <NUM> may be movable between the retracted state (p<NUM>) and the expanded state (p<NUM>) when the stent <NUM> has the contracted outer diameter (D<NUM>), e.g. when fixed to the first and/or second support ring <NUM>, <NUM>, in order to anchor the stent <NUM> into the valve tissue.

The annuloplasty device <NUM> may comprise a cover <NUM> arranged around at least a portion of the first and/or second support ring <NUM>, <NUM>. The cover <NUM> may be configured to promote endothelialization and the ingrowth of cells over the annuloplasty device <NUM>. For example, the cover <NUM> may have a surface which is more porous than the surface of the first- and second support rings <NUM>, <NUM>, which promotes the growth of cells over the annuloplasty device <NUM>. The cover <NUM> may comprise a weave of a textile or a polymer. The stent <NUM> may be arranged around at least a portion of the cover <NUM>. The cover <NUM> may be arranged around the entire length of the first- and second support rings <NUM>, <NUM>.

The stent <NUM> may exert a force onto the cover <NUM> so that the cover <NUM> is pinched between the stent <NUM> and the first and/or second support ring <NUM>, <NUM>, as exemplified in the schematic illustration of <FIG>. Having a cover <NUM> pinched between the stent <NUM> and the first and/or second support ring <NUM>, <NUM>, provides for attaining a secure fixation of the position of the cover <NUM> and the stent <NUM> relative the first and/or second support ring <NUM>, <NUM>. The stent <NUM> may thus strive towards an inner diameter which is smaller than an outer diameter of the cover <NUM> when the latter is arranged around the first and/or second support ring <NUM>, <NUM>, so that a force (F) is exerted radially inwards and pinches the cover <NUM> against the outer surface of the first and/or second support ring <NUM>, <NUM>. In case the stent <NUM> is formed from a temperature activated shape-memory material, the stent <NUM> may increase the force (F) radially inwards as the stent <NUM> is heated to the body temperature, which further increases the strength of the fixation of the stent <NUM> relative the first and/or second support ring <NUM>, <NUM>.

The first support ring <NUM> may comprise a first posterior bow <NUM> and a first anterior portion <NUM>. The second support ring <NUM> may comprise a second posterior bow <NUM>' and a second anterior portion <NUM>'. The first and second posterior bows <NUM>, <NUM>', may be adapted to conform to a posterior aspect of the heart valve, i.e. along the posterior leaflet, having a bow-shaped extension. The first and second anterior portions <NUM>, <NUM>', may each have a straighter extension or at least an extension which is less bent than the bow-shaped posterior sides <NUM>, <NUM>'. This is exemplified in <FIG>. The first and second anterior portions <NUM>, <NUM>', may thus be adapted to conform to an anterior aspect of the heart valve, i.e. along an anterior leaflet. As mentioned, the first support ring <NUM> may be adapted to be arranged on an atrial side of the heart valve, and the second support ring <NUM> may be adapted to be arranged on a ventricular side of the heart valve, as exemplified in <FIG> show schematic top-down view where the second ring <NUM> is shown with dashed lines and the first ring <NUM> is shown with a solid line. The transition point between the first and second rings <NUM>, <NUM>, is in the example of <FIG> at the commissure denoted <NUM>'.

The first anterior portion <NUM> may comprises an anterior stent 105c. The anterior stent 105c comprises a plurality of retention units <NUM> extending towards the second support ring <NUM> in their expanded state (p<NUM>), as schematically illustrated in <FIG>. The second anterior portion <NUM>' may comprise a smooth surface free from retention units <NUM>, as further shown in the example of <FIG>. This provides for a secure anchoring into the tissue with the first anterior portion <NUM> at the atrial side, while at the same time the risk of tissue damage is minimized in the ventricle along the second anterior portion <NUM>'.

The first posterior bow <NUM> may comprise a first posterior stent 105a. The first posterior stent 105a may comprise a first plurality of retention units <NUM> extending towards the second support ring <NUM> in their expanded state (p<NUM>), as schematically illustrated in <FIG>. The second posterior bow <NUM>' may comprise a second posterior stent 105b. The second posterior stent 105b may comprise a second plurality of retention units <NUM>' extending in a direction towards the first plurality of retention units <NUM>. The first and second pluralities of retention units <NUM>, <NUM>', may thus extend in opposite directions along the axial direction <NUM>. Having retention units <NUM>, <NUM>', at both sides along the first and second posterior bows <NUM>, <NUM>', provides for increasing the retention force and the strength by which the annuloplasty device <NUM> is fixated at the valve. The retention units <NUM>, <NUM>', engage the tissue from both sides of the heart valve, 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.

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 annuloplasty device <NUM>. Hence, the retention units <NUM>, <NUM>', may provide for tissue fixation at multiple points across the annuloplasty device <NUM> 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 annuloplasty device <NUM> provides for ease of operation, and a less time consuming procedure than stitching.

Having a plurality of separate stents 105a, 105b, 105c, arranged along the posterior bows <NUM>, <NUM>', and the first anterior portion <NUM> allows further for having the stents 105a, 105b, 105c, displaced from intermediate portions <NUM> extending therebetween. The intermediate portions <NUM> as indicated in <FIG> have a greater radius of curvature than the posterior bows <NUM>, <NUM>', and the anterior portions <NUM>, <NUM>'. Having stents 105a, 105b, 105c, arranged at a distance from the intermediate portions <NUM> provides for maintaining a greater flexibility of the first and second support rings <NUM>, <NUM>, along the intermediate portions <NUM>, and a facilitated bending along the latter.

The retention units <NUM>, <NUM>', may be evenly spaced along the stents <NUM>, 105a, 105b, 105c, as exemplified in <FIG> and <FIG>. Such even distribution of the fixation points provides for a reliable anchoring to the tissue, minimizing the risk of localized pressure peaks. It should be understood however that the distance between each of the retention units <NUM>, <NUM>', may be varied to optimize the anchoring annuloplasty device <NUM> to different anatomies. The first and/or second anterior portion <NUM>, <NUM>', may have <NUM> to <NUM> retention units <NUM>, <NUM>', respectively. The first and/or second posterior portion <NUM>, <NUM>', may have <NUM> to <NUM> retention units <NUM>, <NUM>', respectively. This may provide for a particularly efficient fixation to the tissue while minimizing the overall tissue penetration. It should be understood however that the number of retention units <NUM>, <NUM>', may be varied to optimize the anchoring annuloplasty device <NUM> to different anatomies and valves of different size. In one example the length of the retention units <NUM>, <NUM>', is in the range <NUM> - <NUM>. In another example the length of the retention units <NUM>, <NUM>', is in the range <NUM> - <NUM>, such as <NUM>, which may provide for a particularly advantageous fixation into the tissue while being easy to deploy via a delivery catheter.

The first support ring <NUM> may transition to the second support ring <NUM> over a transition section <NUM>, as illustrated in <FIG>. The stent <NUM> has been omitted from <FIG> for a clearer illustration. The transition section <NUM> is adapted to be arranged at a commissure <NUM>, <NUM>', of the heart valve leaflets, e.g. at a commissure <NUM>' as illustrated in <FIG>. The first and second support rings <NUM>, <NUM>, extend in respective first and second coil planes <NUM>', <NUM>', being essentially perpendicular to the central axis <NUM>. The transition region <NUM> may bend at least partly along the central axis <NUM> so that the first coil plane <NUM>' is separated a distance (d<NUM>) from the second coil plane <NUM>' along the central axis <NUM> (i.e. along a direction parallel to the central axis) at the transition region <NUM>. Having such transition section <NUM> where the coil planes <NUM>', <NUM>', are locally displaced a distance (d<NUM>), and at a position corresponding to the location of the commissure <NUM>, <NUM>', provides for improved accommodation of the first and second support rings <NUM>, <NUM>, to the anatomy at the opposite sides of the valve, in particular as the heart beats. This allows for the retention units <NUM>, <NUM>', of the stent <NUM>, 105a, 105b, 105c, to effectively pierce into the tissue as the first and second support rings <NUM>, <NUM>, accommodate to the anatomy.

Further, having a step-down in the coil planes <NUM>', <NUM>', or an "S-shape", or "Z-shape", at the transition region <NUM> due to separation distance (d<NUM>) provides for a better coaptation of the first and second support rings <NUM>, <NUM>, at the commissure <NUM>, <NUM>'. the risk of having the moving valve leaflets pulling on any of the support rings <NUM>, <NUM>, at the commissure <NUM>, <NUM>', is minimized because the first coil plane <NUM>' of the first support ring <NUM> on the atrial side transitions to the second coil plane <NUM>' of the second support ring <NUM> in a shorter distance at the transition region <NUM> due to the displacement (d<NUM>). This means that the first and second support rings <NUM>, <NUM>, may conform better to the two opposite sides of the valve close to the commissure <NUM>, <NUM>'. The annuloplasty device <NUM> may thus be secured at the valve in a safer manner, while the risk of dislocations is minimized. The position of the transition section <NUM> may be varied depending on which commissure <NUM>, <NUM>', the first/second support rings <NUM>, <NUM>, extend through the valve leaflets. The transition section <NUM> may thus have an increased slope or pitch relative the central axis <NUM> compared to the remaining portions of the first and second support rings <NUM>, <NUM>.

The transition section <NUM> may bend at least partly along a radial direction (r) of the coiled configuration of the first and second support rings <NUM>, <NUM>, where the radial direction (r) is perpendicular to the central axis <NUM>, so that the transition section <NUM> is concave towards the radial direction (r). Such concave bend, or "C-curve", of the transition section <NUM> towards the radial direction (R) provides for further improving the coaptation of the first and second support rings <NUM>, <NUM>, to the valve anatomy close to the commissure <NUM>, <NUM>'. The risk of having a disadvantageous force transfer or friction between the moving valve leaflets and any of the support rings <NUM>, <NUM>, at the commissure <NUM>, <NUM>', is minimized. The first and second support rings <NUM>, <NUM>, may extend along the annulus as far as possible while extending through the commissure <NUM>, <NUM>', with minimized impact on the valve motion, as the concave bend of the transition section <NUM> allows for adapting to anatomies where the commissure <NUM>, <NUM>', is located loser to the central axis <NUM> than the annulus. The annuloplasty device <NUM> may thus be secured at the valve in a further improved manner, while the risk of dislocations in the long term is minimized.

The first and second support rings <NUM>, <NUM>, may have respective free ends <NUM>, <NUM>', as illustrated in <FIG>. The free ends <NUM>, <NUM>', may be configured to be arranged on opposite sides of the native heart valve leaflets. The two free ends <NUM>, <NUM>', may be displaced from each other with a peripheral off-set distance extending in a coil plane. The coil plane is substantially parallel to an annular periphery of the coil formed by the first and second support rings <NUM>, <NUM>, and perpendicular to the axial direction <NUM>. The coil plane accordingly corresponds to the plane spanned by the annular periphery of the device <NUM> when in the coiled configuration. The peripheral off-set distance between the two free ends <NUM>, <NUM>', thus extends substantially perpendicular to the central axis <NUM>. This means that, when the device <NUM> is positioned in the implanted state, around the annulus of the heart valve, the two free ends <NUM>, <NUM>', will be separated along the plane of the valve. Having such off-set <NUM> in the plane of the valve, resulting in a reduced length of the first or second support rings <NUM>, <NUM>, may be advantageous in some anatomies where there might be a risk of interference of the first or second support rings <NUM>, <NUM>, with the valve motion.

A method <NUM> of repairing a defective heart valve is disclosed. The method <NUM> is schematically illustrated in <FIG>, in conjunction with <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 positioning <NUM> a first support ring <NUM> of an annuloplasty device <NUM> on a ventricular side of the heart valve, and positioning <NUM> a second support ring <NUM> of the annuloplasty device on an atrial side of the heart valve. The first and second support rings are thus arranged as a coil extending through a commissure <NUM>, <NUM>' of the heart valve. The first and/or second support ring <NUM>, <NUM>, comprises a stent <NUM>, 105a, 105b, 105c arranged around at least a portion of the first and/or second support ring <NUM>, <NUM>. The stent comprises retention units <NUM>, <NUM>'. The method <NUM> comprises positioning <NUM> the stent <NUM> in abutment with valve tissue along the aforementioned portion of the first and/or second support ring <NUM>, <NUM>, so that the retention units <NUM>, <NUM>', are engaged <NUM> into tissue of the heart valve. The method <NUM> provides for the advantageous benefits as discussed above in relation to the annuloplasty device <NUM> and <FIG>. The method <NUM> allows for a facilitated anchoring of the annuloplasty device <NUM> at the heart valve, due to the robust and reliable fixation mechanism provided by stents <NUM>, 105a, 10b, 105c, and the retention units <NUM>, <NUM>', fixed thereto.

A further method <NUM> is schematically illustrated in <FIG>. The method <NUM> may comprise positioning <NUM> an anterior stent 105c on the atrial side along a first anterior portion <NUM> of the first support ring <NUM>, and positioning <NUM> a first posterior stent 105a on the atrial side along a first posterior bow <NUM> of the first support ring <NUM>. The method <NUM> may further comprise positioning <NUM> a second posterior stent 105b on the ventricular side along a second posterior bow <NUM>' of the second support ring <NUM>.

The method <NUM> may further comprise engaging <NUM> retention units <NUM> of the anterior stent 105c into valve tissue on the atrial side, and engaging <NUM> retention units <NUM>, <NUM>', of the first and second posterior stents 105a, 105b, into valve tissue on the respective atrial and ventricular side to anchor the annuloplasty device <NUM> at the heart valve. A secure fixation of the annuloplasty device at the opposite sides of the heart valve leaflets is thus provided, as described further above with respect to <FIG>.

The method <NUM> may comprise positioning the first and second support rings <NUM>, <NUM>, on the respective atrial and ventricular sides of the heart valve by ejecting <NUM> the first and second support rings from a delivery catheter (not shown), where the retention units <NUM>, <NUM>', move from a retracted state (p<NUM>) to an expanded state (p<NUM>) as the first and second support rings <NUM>, <NUM>, are ejected from the delivery catheter.

The retention units <NUM>, <NUM>', may be aligned essentially flush with an outer diameter (D) of the stent <NUM>, 105a, 105b, 105c, in the retracted state (p<NUM>) when the first and second support rings <NUM>, <NUM>, moves along a lumen if the delivery catheter.

Claim 1:
An annuloplasty device (<NUM>) comprising
first (<NUM>) and second (<NUM>) support rings having a coiled configuration in which the first and second support rings are arranged as a coil around a central axis (<NUM>),
wherein the first and second support rings are configured to be arranged on opposite sides of native heart valve leaflets (<NUM>) of a heart valve, characterized by
a stent (<NUM>, 105a, 105b, 105c) arranged around at least a portion of the first and/or second support ring,
wherein the stent comprises retention units (<NUM>, <NUM>'), and
wherein the stent is radially contractible along a radial direction (R), perpendicular to a longitudinal direction (L) of the stent, so that the stent exerts a force (F) on the first and/or second support ring.