Patent Publication Number: US-2021177596-A1

Title: Annuloplasty implant

Description:
FIELD OF THE INVENTION 
     This invention pertains in general to the field of cardiac valve replacement and repair. More particularly the invention relates to an annuloplasty implant, such as an annuloplasty ring or helix, for positioning at the heart valve annulus, a method of manufacturing an annuloplasty implant, and a method of repairing a defective heart valve. 
     BACKGROUND OF THE INVENTION 
     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. 
     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. A related method would also be advantageous. 
     SUMMARY OF THE INVENTION 
     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 support rings being adapted to be arranged as a coil in a coiled configuration around an axial direction, wherein the first and second support rings are adapted to be arranged on opposite sides of native heart valve leaflets of a heart valve to pinch said leaflets, fastening units fixed to the first support ring, wherein the fastening units are configured for interlocking with the second support ring via deformation of the fastening units when in the coiled configuration. 
     According to a second aspect a method of manufacturing an annuloplasty implant is provided comprising forming first and second support rings configured to be arranged in a coiled configuration around an axial direction, forming fastening units integrated into the first support ring, wherein the fastening units are configured for interlocking with the second support ring via deformation of the fastening units when in the coiled configuration. 
     According to a third aspect a method of repairing a defective heart valve is provided, comprising positioning first and second support rings of an annuloplasty implant in a coiled configuration on opposite sides of native heart valve leaflets of the heart valve, interlocking fastening units integrated into the first support ring with the second support ring by deforming the fastening units. 
     Further examples of the invention are defined in the dependent claims, wherein features for the second and subsequent aspects 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 manufacturing of an annuloplasty implant. 
     It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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 
         FIG. 1  is a schematic illustration of an annuloplasty implant according to an example of the disclosure; 
         FIG. 2  is a schematic illustration of an annuloplasty implant, when in a stretched elongated configuration, according to an example of the disclosure; 
         FIGS. 3 a - b    are detail views of a fastening unit and a corresponding recess in a support ring, when separated, according to examples of the disclosure; 
         FIG. 3 c    is a detail view of a fastening unit and a corresponding recess in a support ring, when in an interconnected configuration, according to an example of the disclosure; 
         FIG. 4 a    is a detail view of a fastening unit and a corresponding recess in a support ring, when separated, according to an example of the disclosure; 
         FIG. 4 b    is a detail view of a fastening unit and a corresponding recess in a support ring, when in an interconnected configuration, according to an example of the disclosure; 
         FIG. 5 a    is a detail view of a fastening unit and a corresponding recess in a support ring, when separated, according to an example of the disclosure; 
         FIG. 5 b    is a detail view of a fastening unit and a corresponding recess in a support ring, when in an interconnected configuration, according to an example of the disclosure; 
         FIG. 6 a    is a schematic illustration of an annuloplasty implant according to an example of the disclosure; 
         FIG. 6 b    is a schematic illustration of an annuloplasty implant, when in an implanted state, according to an example; 
         FIG. 7 a    is a flow chart of a method of manufacturing an annuloplasty implant according to an example; 
         FIG. 7 b    is another flow chart of a method of manufacturing an annuloplasty implant according to one example; 
         FIG. 8 a    is a flow chart of a method of repairing a defective heart valve according to an example; and 
         FIG. 8 b    is another flow chart of a method of repairing a defective heart valve according to one example. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Specific embodiments of the invention will now be described with reference to the accompanying drawings. 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 scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements. 
     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. 1  is a schematic illustration of an annuloplasty implant  100  comprising first  101  and second  102  support rings being adapted to be arranged as a coil in a coiled configuration around an axial direction  103 . The first and second support rings  101 ,  102 , are adapted to be arranged on opposite sides of native heart valve leaflets of a heart valve, as illustrated in  FIG. 6 b   . As shown in  FIG. 6 b   , the first support  101  may be arranged on an atrial side of the valve, and the second support  102  may be arranged on a ventricular side. The first and second supports  101 ,  102 , are connected to form a coil- or helix shaped ring. The coil extends through the valve opening (dashed line) at a commissure  401  thereof. In the examples of  FIGS. 6 a   - b,  the second support  102 , positioned on the ventricular side, forms a complete loop, whereas the first support  101 , positioned on the atrial side, has a reduced length along its periphery, as will be described further below. The implant  100  may comprise a shape-memory material, so that the implant  100  assumes the coiled configuration after having been ejected from a delivery catheter. While in the delivery catheter the implant  100  may be stretched in an elongated shape, i.e. as illustrated in  FIG. 2 . Alternatively, the implant  100  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  100 . The implant  100  comprises fastening units  105 ,  105 ′, fixed to the first support ring  101 . The fastening units  105 ,  105 ′, are configured for interlocking with the second support ring  102  via deformation of the fastening units  105 ,  105 ′, when in the coiled configuration.  FIG. 6 b    is a schematic illustration showing the fastening units  105 ,  105 ′, being interlocked with the second support  102 . I.e. the first and second support rings  101 ,  102 , are configured to be arranged on opposite sides of native heart valve leaflets of the heart valve to pinch the leaflets when the fastening units  105 ,  105 ′, are interlocked with the second support  102 . Having fastening units  105 ,  105 ′, interlocking with the second support  102  by being deformed provides for a particularly strong and robust fixation of the annuloplasty implant  100  at the heart valve, since the deformation of the material of the fastening units  105 ,  105 ′, allows for said material to conform to the structure and shape of the second support  102 , so that an interlocked connection can be formed therebetween, via mating surfaces of the fastening units  105 ,  105 ′, and the second support  102 . This also provides for interlocking the first and second supports  101 ,  102 , with a force fit connection, which does not necessitate cumbersome connection mechanisms, such as screws, sutures or the like, which require a lengthier and more precise manipulation by the operator in order to be fixed into position. Such precise manipulation is difficult to execute on the beating heart, due to the significant movement of the surrounding anatomy. The force-fit connection provided by the deformable fastening units  105 ,  105 ′, for interlocking with the second support  102  this allows for a quicker and safer procedure. Furthermore, since the fastening units  105 ,  105 ′, are fixed to the first support  101 , the number of components that must be navigated to, and manipulated at, the target site can be minimized. I.e. suturing devices or other fixation elements or tools can be dispensed with. 
     Although the fastening units  105 ,  105 ′, are fixed to the first support  101  in the example in e.g.  FIGS. 6 a   - b,  it is conceivable that the fastening units  105 ,  105 ′, can be fixed to the second support  102  positioned on the ventricular side, for interlocking with the first support  101  at the atrial side. The number of fastening units  105 ,  105 ′, can also be varied to optimize the retention strength when interlocked with the second support  102 . 
     The fastening units  105 ,  105 ′, may be integrated into the first support ring  101 , e.g. by being formed from the material of the first support ring  101 . This may provide for an enhanced structural integrity of the fastening units  105 ,  105 ′. The fastening units  105 ,  105 ′, may be hence cut from the material of the first support  101 .  FIG. 3 a - b    shows an example of a fastening units  105  being cut from the material of the first support  101 .  FIG. 3 a    show an example of an implant  100  in a stretched elongated configuration, and the different sections thereof. As mentioned, the fastening units  105 ,  105 ′, may be provided on the first support  101 , and as described further below, the fastening units  105 ,  105 ′, may interlock with structures arranged on the second support  102  such as recesses  106 ,  106 . An intermediate portion  119 , without fastening units  105 ,  105 ′, may be positioned therebetween. The intermediate portion  119  may thus be positioned to be arranged at the anterior side when the implant  100  is attached to the heart valve, as schematically illustrated in  FIG. 6 b   . The intermediate portion  119  may thus comprise a smooth surface free from fastening units  105 ,  105 ′. This may ensure that there is no risk of piercing the tissue at the anterior side of the valve.  FIGS. 3 a   - c,    4   a - b,  and  5   a - b  are magnified views of sections of the implant  100  showing examples of the fastening units  105 ,  105 ′, and recesses  106 . 
     In the case the fastening units  105 ,  105 ′, are formed from the material of the first support  101 , the material may be removed from an initially substantially circular cross-section of the support  101  to create fastening units  105 ,  105 ′, as shown in the cross-section of  FIG. 3 b   . The upper part of  FIG. 3 b   , showing the fastening unit  105  thus corresponds to the cross-section of the first support  101  in  FIG. 2 , and the lower part of  FIG. 3 b    shows an example of a cross-section of the second support  102  in  FIG. 2 , illustrating the recess  106  into which the fastening unit  105  may interlock.  FIGS. 3 a  and 3 c    show magnified views in the lengthwise direction, i.e. as illustrated in  FIG. 2 , but when the second support  102  has been bent into a position opposite the first support  101  so that the fastening units  105 ,  105 ′, are arranged opposite the recesses  106 ,  106 ′. 
     The fastening units  105 ,  105 ′, may be cut to form various shapes to facilitate the deformation thereof when interlocking with the second support and optimizing the retention force when in the interlocked state. The fastening units  105 ,  105 ′, may be formed by different cutting techniques such as milling or laser cutting techniques. It is also conceivable that the fastening units  105 ,  105 ′, may be fixed or integrated onto the first support  101  by other methods, or by being formed from other materials. The support  101 ,  102 , 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  101 ,  102 , may be formed from a hollow tube, or other hollow structures with the mentioned cross-sections. The support  101 ,  102 , may be formed from a sandwiched laminate material, comprising several layers of different materials, or different layers of the same material. The support  101 ,  102 , may be formed from a stent or a stent-like structure, and/or a braided material. The support  101 ,  102 , may be formed from a braid of different materials braided together, or from a braid of the same material. The support  101 ,  102 , may be formed from NiTinol, or another suitable bio-compatible material. The surfaces of the first and second supports  101 ,  102 , 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. 
     Hence, the fastening units  105 ,  105 ′, may comprise extensions  105 ,  105 ′, configured to interlock with corresponding recesses  106 ,  106 ′, arranged in the second support ring  102 , as exemplified in  FIGS. 1-5 . The recesses  106 ,  106 ′, have been omitted in  FIGS. 6 a - b    for the purpose of clarity of presentation. FIGS.  3   a - c,    4   a - b,  and  5   a - b,  show different examples of recesses  106  being shaped and configured to interlock with corresponding fastening units  105  which deforms when interlocking with the recesses  106 . This provides for a robust force fit connection that allows for a safe and facilitated clamping of the support rings  101 ,  102 , on the opposite sides of the valve leaflets for an efficient pinching thereof and remodeling of the valve annulus. 
     The fastening units  105 ,  105 ′, may be configured to be plastically deformed when interlocking with the second support ring  102 . Plastically deforming the fastening units  105 ,  105 ′, allows for a strong irreversible connection to the second support  102 . The fastening units  105 ,  105 ′, may comprise a material that is configured to irreversibly engage a corresponding mating surface  107  of the second support ring  102  for interlocking with the mating surface  107  in a locked state.  FIG. 3 a    show an example where the fastening unit  105  has a tapered shape towards a distal tip thereof.  FIG. 3 b    is a cross-section seen along a longitudinal extension of the support  101 , showing the same tapered shape. In  FIG. 3 c   , the tapered fastening unit  105  has been pushed into recess  106  so that the distal tip of the tapered shape as been deformed to fill up a void in the recess, defined by the mating surface  107 . The fastening unit  105  may thus interlock with the recess  106  with the fastening principle of a rivet.  FIGS. 4 a - b    show another example where the fastening unit  105  has an initial blunt distal tip ( FIG. 4 a   ), before being pushed into the recess  106  ( FIG. 4 b   ) to be deformed against the mating surface  107  and further compressed to assume a shape which is increasingly circular. In both examples, the recess  106  has a narrow neck portion at the entrance of the void of the recess  106 . The deformed fastening unit  105  will thus deform and expand to fill a wider portion of a bottom of the void of the recess  106 , so that the narrow neck portion at said entrance will provide a counter force against the deformed fastening unit  105 . 
     The extensions, i.e. the fastening units  105 , may have a delivery configuration (A) and a deformed configuration (B) in the locked state in which the extensions are deformed to at least partly fill corresponding recesses  106  in the second support ring  102  with a deformed portion  108  of a material of the fastening units  105 ,  105 ′, as illustrated in  FIG. 3 a , 3 c   , and  FIGS. 4 a   - b.  The recesses  106  thus comprise the mating surface  107 . The deformed portion  108  may not fill the recess  106  completely as shown in the discussed example, but sufficiently to allow a counter force to act against the deformed fastening unit  105  as elucidated above. 
     The first support ring  101  may be configured to be clamped to the second support ring  102  so that the fastening units  105 ,  105 ′, are deformed for said interlocking. The clamping may be provided by a clamping tool that push the fastening units into the corresponding recesses with a sufficient force to deform the fastening units  105 ,  105 ′, in the recesses  106 ,  106 ′. 
     Although the discussed examples show recesses  106 ,  106 ′, for interlocking with the extensions of the fastening units  105 ,  105 ′, it is conceivable that the fastening units  105 ,  105 ′, may interlock with the second implant  102  in other ways. The fastening units  105 ,  105 ′, may e.g. be deformed to clamp onto the outside of the second support  102 , thus allowing interlocking without recesses  106 ,  106 ′. 
     The recesses  106 ,  106 ′, may comprise through holes  109  in the second support ring  102 , as shown in  FIGS. 5 a   - b.  The fastening units  105 ,  105 ′, may be configured to be elastically or plastically deformed when arranged to extend across the through holes  109  for interlocking with the second support  102 . In  FIG. 5 b   , an example is shown where the fastening unit  105  comprise a retention unit  113  configured to be elastically deformed when pushed into the through hole  109 . The retention unit  113  is configured to be subsequently expanded for interlocking with the opposite side of the through hole  109  as illustrated. This provides for a secure interlocking with the second support  102 . 
     The first and second support rings  101 ,  102 , may comprise substantially flat opposite surfaces  110 ,  111 , arranged against each other when the fastening units  105 ,  105 ′, are interlocked with the second support ring  102 . The extensions of the fastening units  105 ,  105 ′, may thus extend from a first flat surface  110  of the first ring  101  towards corresponding recesses  106 ,  106 ′, formed in a second opposite surface  111  of the second support ring  102 , as illustrated in e.g.  FIGS. 2, 3   a - c.  This may provide for a compact cross-section of the implant  100  and further a facilitated interlocking due to the flat surfaces  110 ,  111 , supporting each other. 
     The recesses  106 ,  106 ′, may comprise sloped surfaces  112  arranged so that the corresponding extensions can slide against the slope surfaces  112  when interlocking with the recesses  106 ,  106 ′. Thus, the fastening units  105 ,  105 ′, as shown in  FIGS. 3 a   - b,  may be guided against the slope surfaces  112  into the recesses  106 ,  106 ′, facilitating the interlocking. 
     The first support ring  101  may be adapted to be arranged on an atrial side of the heart valve, and the second support ring  102  may be adapted to be arranged on a ventricular side of the heart valve. The first support ring  101  may comprise a first posterior bow  114  and the second support ring  102  may comprise a second posterior bow  114 ′, as illustrated in  FIG. 6 a   . The fastening units  105 ,  105 ′, may be arranged on the first posterior bow  114  for interlocking with the second posterior bow  114 ′, as illustrated in  FIG. 6 b   . As mentioned above, this allows for a secure fixation of the implant  100  while minimizing risk of damaging tissue at the critical portions of the anatomy at the anterior side, at the anterior portion  119  of the implant  100 . 
     The first and second support rings  101 ,  102 , may have respective free ends  115 ,  115 ′, configured to be arranged on opposite sides of the native heart valve leaflets, when in the coiled configuration. The two free ends  115 ,  115 ′, may be displaced from each other with a peripheral off-set distance  116  extending in a coil plane  117 , as illustrated in  FIG. 6 a   . The coil plane  117  is substantially parallel to an annular periphery  118  of the coil and perpendicular to the central axis  103 . The coil plane  117  accordingly corresponds to the plane spanned by the annular periphery  118  of the implant  100  when assuming the coiled configuration. The peripheral off-set distance  116  between the two free ends  115 ,  115 ′, thus extends substantially perpendicular to the central axis  103 . This means that, when the implant  100  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  116  in the plane of the valve, the resulting reduced length of the first or second support member  101 ,  102 , will allow for reducing the number of fastening units  105 ,  105 ′, required to securely fixate the implant  100  at the valve, while at the same time providing for a sufficient overlap of the first and second support member  101 ,  102 , 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 fastening units  105 ,  105 ′, on the anterior side may be associated with high risk, as discussed above. This can therefore be avoided, by having the off-set  116  as specified. Furthermore, the interference of the implant  100  with the movements of the valve will be minimized. Fastening of the implant  100  on the atrial side can thus be accomplished by fixation of the posterior bows  114 ,  114 ′, and there will be no interference on the atrial side with the movement of the valve, due to the off-set distance  116  reducing the circle sector of the first support  101 . 
       FIG. 7 a    illustrates a method  200  of manufacturing an annuloplasty implant  100 . The order in which the steps of the method  200  are illustrated should not be construed as limiting and it is conceivable that the order in which the steps of the method  200  is carried out may be varied. The method  200  comprises forming  201  first  101  and second  102  support rings configured to be arranged in a coiled configuration around an axial direction  103 , and forming  202  fastening units  105 ,  105 ′, integrated into the first support ring  101 . The fastening units  105 ,  105 ′, are configured for interlocking with the second support ring  102  via deformation of the fastening units when in the coiled configuration. Thus, the method  200  thus provides for an annuloplasty implant  100  with the advantageous effects described above in relation to  FIGS. 1-6 . 
       FIG. 7 b    illustrates a further method  200  of manufacturing an annuloplasty implant  100 . The order in which the steps of the method  200  are illustrated should not be construed as limiting and it is conceivable that the order in which the steps of the method  200  is carried out may be varied. The method  200  may comprise forming  203  recesses  106 ,  106 ′, integrated into the second support ring  102 , being configured to interlock with the fastening units  105 ,  105 ′, when the implant  100  is in the coiled configuration. 
       FIG. 8 a    illustrates a method  300  of repairing a defective heart valve. The order in which the steps of the method  300  are illustrated should not be construed as limiting and it is conceivable that the order in which the steps of the method  300  is carried out may be varied. The method  300  comprises positioning  301  first and second support rings  101 ,  102 , of an annuloplasty implant  100  in a coiled configuration on opposite sides of native heart valve leaflets of the heart valve, and interlocking  302  fastening units  105 ,  105 ′, integrated into the first support ring  101  with the second support ring  102  by deforming  303  the fastening units  105 ,  105 ′. The method  300  thus provides for the advantageous effects described above in relation to  FIGS. 1-6 . 
       FIG. 8 b    illustrates a further method  300  of repairing a defective heart valve. The order in which the steps of the method  300  are illustrated should not be construed as limiting and it is conceivable that the order in which the steps of the method  300  is carried out may be varied. Deforming the fastening units  105 ,  105 ′, may comprise plastically deforming  304  extensions  105 ,  105 ′, of the fastening units so that a deformed portion  108  of a material of the fastening units  105 ,  15 ′, at least partly fill corresponding recesses  106 ,  106 ′, in the second support ring  102 , arranged opposite the extensions. A secure and reliable fixation of the implant  100  at the heart valve is thus provided. 
     The present invention has been described above with reference to specific embodiments. However, other embodiments than the above described are equally possible within the scope of the invention. The different features and steps of the invention may be combined in other combinations than those described. The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used.