Patent Publication Number: US-2020281722-A1

Title: Medical system for annuloplasty

Description:
FIELD OF THE INVENTION 
     This invention pertains in general to the field of annuloplasty devices for treating a defective mitral valve. More particularly the invention relates to a medical system of devices for treating a defective mitral valve via coronary sinus and an annuloplasty implant for fixation of the annulus, and a method therefore. 
     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. 
     Implants have previously been introduced into the coronary sinus (CS) in order to affect the shape of the valve annulus and thereby the valve function. U.S. Pat. No. 6,210,432 and WO02/062270 discloses such implant that is aimed to replace annuloplasty rings. Permanent implants have several disadvantageous effects, for example since they are implanted into the CS which is a source for later complications. Thus, a problem with the prior art implants in the CS is that such implants may be less effective in retaining the desired geometry of the annulus. It may be necessary for the implants to be positioned in the CS for a lengthy time in order to sustain the correct function of the valve. This pose significant requirements on the long-term function of the implant, that may not be as effective as annuloplasty rings to start with. A further problem with prior art is thus that complex and difficult-to-operate devices must be deployed in the CS, that may require frequent adjustment and repositioning to ensure the correct function over time. Another problem with prior art devices is the traumatic effects on the CS itself, due to fixation structures that must ensure the correct position of the device in the CS over time. Another problem is to ensure that a significant part of the annulus is reshaped while providing for atraumatic engagement with the anatomy. 
     The above problems may have dire consequences for the patient and the health care system. Patient risk is increased. 
     Hence, an improved annuloplasty device for performing downsizing and reshaping of the valve annulus would be advantageous and in particular allowing for ensuring long-term functioning, less complex procedure, and less traumatic effects on the anatomy and increased patient safety. Also, a method of downsizing and reshaping the mitral valve annulus with such medical annuloplasty device would 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 device is provided for treating a defective mitral valve having an annulus, comprising a removable and flexible elongate displacement unit for temporary insertion into a coronary sinus (CS) adjacent the valve, wherein the displacement unit has a delivery state for delivery into the CS, and an activated state to which the displacement unit is temporarily and reversibly transferable from said delivery state, the displacement unit comprises a proximal reversibly expandable portion, a distal anchoring portion being movable in relation to the proximal expandable portion in a longitudinal direction of the displacement unit to said activated state in which the shape of the annulus is modified to a modified shape, wherein the proximal expandable portion is reversibly foldable to an expanded state for positioning against a tissue wall at the entrance of the CS, and wherein the distal anchoring portion comprises an inflatable unit. 
     According to a second aspect medical system for treating a defective mitral valve having an annulus is provided. The system comprises in combination; an annuloplasty device for treating a defective mitral valve having an annulus, comprising a removable and flexible elongate displacement unit for temporary insertion into a coronary sinus (CS) adjacent the valve, wherein the displacement unit has a delivery state for delivery into the CS, and an activated state to which the displacement unit is temporarily and reversibly transferable from said delivery state, the displacement unit comprises a proximal reversibly expandable portion, a distal anchoring portion being movable in relation to the proximal expandable portion in a longitudinal direction of the displacement unit to said activated state in which the shape of the annulus is modified to a modified shape, wherein the proximal expandable portion is reversibly foldable to an expanded state for positioning against a tissue wall at the entrance of the CS, and wherein the distal anchoring portion comprises an inflatable unit. The system comprises an annuloplasty device for permanent fixation at the mitral valve annulus by annuloplasty of the valve when said modified shape is obtained, wherein said annuloplasty device comprises a loop structure, such as a helix-shaped loop structure, configured to be positioned on either side of said valve to retain said modified shape of the annulus, wherein at least a portion of the loop structure conforms to a curvature of said annulus. 
     According to a third aspect a method is provided for treating a defective mitral valve having an annulus, the method comprises inserting a flexible and removable elongate displacement unit in a delivery state into a coronary sinus (CS) adjacent said valve, positioning a proximal expandable portion against a tissue wall at the entrance of said CS, anchoring a distal anchoring portion comprising an inflatable unit inside the CS by expanding of the inflatable unit, activating the displacement unit in an activated state whereby the distal anchoring portion is moved in a longitudinal direction of the displacement unit to reduce a distance (L) between the distal anchoring portion and the proximal expandable portion such that the shape of the annulus is modified to a modified shape, fixating an annuloplasty device at the mitral valve annulus when said modified shape is obtained, whereby said annuloplasty device comprises a loop structure, such as a helix-shaped loop structure, positioned on either side of the valve to retain the modified shape of the annulus, wherein at least a portion of the loop structure is conformed to a curvature of said annulus, removing the elongate displacement unit after temporary activation in the activated state. 
     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 long-term functioning of the mitral valve. 
     Some examples of the disclosure provide for less complex downsizing procedures of the mitral valve. 
     Some examples of the disclosure provide for a reduced risk of damaging the anatomy such as the CS. 
     Some examples of the disclosure provide for a secure downsizing while at the same time reducing the risk of damaging the anatomy such as the CS. 
     Some examples of the disclosure provide for improved downsizing of the mitral valve annulus while ensuring an atraumatic procedure. 
     Some examples of the disclosure provide for reduced risk of long-term negative effects of CS implants. 
     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 a    is a schematic illustration of an annuloplasty device according to one example; 
         FIG. 1 b    is a schematic illustration of an annuloplasty device, with an expanded proximal portion, according to one example; 
         FIG. 2 a    is a schematic illustration of an annuloplasty device, with an expanded proximal portion, according to one example; 
         FIG. 2 b    is a detailed view of the distal portion of the annuloplasty device in  FIG. 2 a   , according to one example; 
         FIGS. 3 a - b    are schematic illustrations of an annuloplasty device, with different lengths between proximal and distal portions, according to one example; 
         FIG. 4  is a schematic illustration of an annuloplasty device according to one example; 
         FIG. 5  is a schematic illustration of a medical system for treating a defective mitral valve when placed in the heart, according to one example; 
         FIG. 6 a    is a flow chart of a method for treating a defective mitral valve according to one example; and 
         FIG. 6 b    is a flow chart of a method for treating a defective mitral 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  schematically illustrates an annuloplasty device  100  for treating a defective mitral valve having an annulus. The annuloplasty device  100  comprises a removable and flexible elongate displacement unit  101  for temporary insertion into a coronary sinus (CS) adjacent the mitral valve.  FIG. 5  is an illustration of the heart showing the CS in relation to the mitral valve (MV) in a top-down view. The CS lies adjacent the MV and follows a curvature around the annulus (A) of the MV. The displacement unit  101  has a delivery state for delivery into the CS, and an activated state to which the displacement unit  101  is temporarily and reversibly transferable from said delivery state. The displacement unit  101  comprises a proximal reversibly expandable portion  102 , and a distal anchoring portion  103  being movable in relation to the proximal expandable portion in a longitudinal direction  104  of the displacement unit  101  to said activated state, so that a distance (L) between the proximal portion  102  and the distal anchoring portion  103  can be varied as seen in  FIGS. 3 a - b   . In the activated state, the annuloplasty device  100 , when placed in the CS, modifies the annulus to a modified shape where the annulus is downsized and the leaflets may co-apt. The proximal expandable portion  102  is reversibly foldable to an expanded state for positioning against a tissue wall at the entrance of the CS.  FIG. 5  illustrates schematically how the proximal expandable portion  102  is positioned outside the CS, for pushing against the wall at the entrance of the CS. The distal anchoring portion  103  comprises an inflatable unit, such as a balloon. This provides for efficient and non-traumatic fixation of the distal end of the displacement unit  101 , which in combination with the efficient anchoring against the wall of the CS by the proximal portion  102 , allows for an efficient transfer of a contracting force of the proximal and distal portions  102 ,  103 , towards each other. This allows for an effective modification of the radius of curvature of the CS to facilitate modifying the shape of the valve annulus. The modified shape of the annulus may then be fixed by attachment of an annuloplasty device  301  to the valve, as described further below, before removing the displacement unit  101 . The proximal expandable portion  102  and the distal anchoring portion  103  may be connected to different sheaths or wires, that may be independently movable in the longitudinal direction  104  to provide for varying the distance (L) as illustrated in  FIGS. 3 a   - b.    
     The proximal expandable portion  102  may comprise expandable bows  105  extending in the longitudinal direction  104 , as schematically illustrated in e.g.  FIGS. 1 a - b   . Having such expandable bows  105  provides for to further lessen the risk of damaging the tissue at the entrance of the CS, since a soft apposition against the tissue may be provided, in absence of sharp edges or kinks. Having the bows  105  extending in the longitudinal direction  104  also facilitates a symmetric engagement against the tissue wall, with an even transfer of force around the entrance to the CS, hence allowing for a robust anchoring. The longitudinal extension of the bows  105  also provides for facilitated expansion of the bows  105  by applying a force to the bows  105  in the longitudinal direction  104 . The bows  105  may extend with a curvature forming an apex  116  at the middle portion of the bow  105 , where the apex  116  is positioned at the maximum expanded diameter of the proximal expandable portion  102 . Both portions of the bow  105  extending from the apex  116  may extend in the longitudinal direction  104 . A plurality of bows  105 ,  105 ′, may be arranged circumferentially so that a force may be applied symmetrically and evenly around the tissue wall. 
     The expandable bows  105  may be connected to a sheath  106  and may be configured to be expanded in a radial direction  115 , perpendicular to the longitudinal direction  104 , by pushing a proximal portion  107  of the sheath  106  towards the distal anchoring portion  103 , as indicated in  FIG. 1 b    (see arrow adjacent sheath  106 ). This provides for a facilitated deployment of the bows  105  to the expanded configuration. The sheath  116  may be pushed in relation to a distal portion  117  attached distally to the bows  105 . The compressive force between the distal portion  117  and the proximal portion  107  may thus push the bows  105  radially outwards. It is conceivable however that the bows  105  may comprise a shape-memory material having a tendency to assume the expanded configuration in its relaxed state, and that the bows may be confined in an outer sheath (not shown) being pulled back so that the bows  105  spring into the expanded configuration. 
     The bows  105  may comprise elongated ribs  108  formed in the sheath  106  by elongated cuts  108 ′ in the sheath  106 , extending in the longitudinal direction  104 , as schematically illustrated in  FIG. 1 a   . This provides for a simple and robust construction from which the expandable bows  105  provided. The bows  105  may thus be formed from the same material as the sheath  106 . The mentioned material may be a soft flexible material which is non-traumatic to tissue. In the collapsed configuration seen in  FIG. 1 a   , the ribs  108 , i.e. the soon to be expanded bows  105 , extend in the longitudinal direction  104 , and provides for a compact radial profile. 
     The bows  105  may be placed equidistantly around a circumference of the sheath  106 . As elucidated above, this may provide for an even distribution of the anchoring force. 
     When the proximal expandable portion  102  is folded to the expanded state, the expandable bows  105  may extend with a curvature forming an apex  116  positioned at a maximum expanded diameter (D) of the proximal expandable portion  102 . Each of the bows  105  may extend with two expanded sections  118 ,  118 ′, towards the apex  116 , as illustrated in  FIG. 4 . The two expanded sections  118 ,  118 ′, may comprise a proximal expanded section  118 ′ and a distal expanded section  118 . The distal expanded section  118  is configured to be arranged against the tissue wall at the entrance of the CS. At least a portion of the distal expanded section  118  may extend in a first direction  119  forming a first angle (v 1 ) with the radial direction  115 , and at least a portion of the proximal expanded section  118 ′ may extend in a second direction  119 ′ forming a second angle (v 2 ) with the radial direction  115 . The first angle (v 1 ) may be less than the second angle (v 2 ), as further shown in the example of  FIG. 4 . This provides for improving the support of the proximal expandable portion  102  against the tissue wall at the entrance of the CS. I.e. since the angle (v 1 ) of the distal expanded section  118  is reduced compared to the second angle (v 2 ) the distal expanded section  118  will be more parallel to the radial direction  115  than the proximal expanded section  118 ′. Since the tissue wall is typically also substantially parallel to the radial direction  115 , the surface area of the distal expanded section  118  in contact with the tissue wall will increase. This provides for a more stable and robust anchoring point with less risk of movement of the in the proximal expandable portion  102  relative the tissue wall in the longitudinal direction  104 . In some examples, the first direction  119  may be substantially parallel with the radial direction  115 , which provides for a stable positioning of the proximal expandable portion  102  relative the tissue wall at the entrance of the CS. 
     The maximum expanded diameter (D) of the proximal expandable portion  102  may be at least three times the diameter of the CS. In some examples the ratio of the maximum expanded diameter (D) of the proximal expandable portion  102  to the diameter of the CS is in the range 3-5. In some examples the aforementioned ratio may be in the range 3.5-4.5, which provides for a particular advantageous anchoring of the proximal expandable portion  102 , while maintaining a compact and easy to use device  100 . 
     The elongate displacement unit  101  may comprise a lumen  109  extending in the longitudinal direction  104 . The lumen may have a distal opening  110  arranged distally of the inflatable unit  103 , and at least one proximal opening  111 ,  111 ′, arranged between the inflatable unit  103  and the proximal expandable portion  102 , as schematically illustrated in  FIGS. 2 a - b   . This provides for minimizing the risk of occlusion in the CS, since blood may flow between the distal opening  110  and the at least one proximal opening  111 ,  111 ′. The number of openings  111 ,  111 ′, may be varied to optimize the flow and minimize the risk of occlusion. 
     The annuloplasty device  100  may comprise a guide wire  114  arranged to extend inside the lumen  109  and to exit the lumen  109  at the distal opening  110 . This provides for facilitated positioning of the elongate displacement unit  101 . The lumen  109  may thus allow for both guiding of the guide wire  114  and for transport of blood between proximal openings  111 ,  111 ′, and the distal opening  110 , which provides for a robust and compact annuloplasty device  100 . 
     The elongate displacement unit  101  may comprise at least one radiopaque marker  112 ,  112 ′, arranged inside the inflatable unit  103 , as schematically illustrated in  FIG. 2 b   . The radiopaque marker  112 ,  112 ′, is visible in medical imaging methods. The radiopaque marker  112 ,  112 ′, may be arranged in the elongate displacement unit  101  and at a portion thereof extending through the inflatable unit  103 . This provides for determining the position of the inflatable unit  103  while maintaining a robust and low-profile annuloplasty device  100 . 
     The annuloplasty device  100  may comprise an inflation lumen  113  connected to inflatable unit  103  and configured to deliver an inflation medium to the inflatable unit  103 , as schematically illustrated in  FIG. 2   b.    
     As mentioned, the distance (L) between the proximal expandable portion  102  and the distal anchoring portion  103  in the longitudinal direction  104  may be decreased to a reduced distance (L′) when the displacement unit  101  is transferred from the delivery state to the activated state, as schematically illustrated in  FIGS. 3 a   - b.    
     A medical system  200  is provided for treating a defective mitral valve having an annulus, as schematically illustrated in  FIG. 5 . The system  200  comprises in combination an annuloplasty device  100  as described above in relation to  FIGS. 1-4 , and an annuloplasty implant  301 . As described, the annuloplasty device  100  comprises a removable and flexible elongate displacement unit  101  for temporary insertion into a coronary sinus (CS) adjacent the valve, wherein the displacement unit  101  has a delivery state for delivery into the CS, and an activated state to which the displacement unit  101  is temporarily and reversibly transferable from said delivery state. The displacement unit  101  comprises a proximal reversibly expandable portion  102 , a distal anchoring portion  103  being movable in relation to the proximal expandable portion  102  in a longitudinal direction  104  of the displacement unit  101  to said activated state in which the shape of the annulus is modified to a modified shape. The proximal expandable portion  102  is reversibly foldable to an expanded state for positioning against a tissue wall at the entrance of the CS, and the distal anchoring portion  103  comprises an inflatable unit. The annuloplasty implant  301  is configured for permanent fixation at the mitral valve annulus by annuloplasty of the valve when said modified shape is obtained. The annuloplasty device  301  comprises a loop structure  302 , such as a helix-shaped loop structure, configured to be positioned on either side of said valve to retain said modified shape of the annulus, wherein at least a portion of the loop structure conforms to a curvature of said annulus. The system  200  thus provides for the advantageous benefits as described in relation to the annuloplasty device  100  above, e.g. providing for efficient downsizing of the valve annulus and for subsequent fixation of the modified shape by the annuloplasty implant  301  as schematically illustrated in  FIG. 5 . 
     The annuloplasty implant  301  may comprise a first support ring and a second support ring, being arranged in a coiled configuration around an axial direction. The first and second support rings may be adapted to be arranged on opposite sides of native heart valve leaflets to pinch said leaflets. The annuloplasty implant  301  may have shape-memory properties, such that the first and second supports may assume an elongated configuration when delivered in a catheter, whereupon the first and second supports may assume the coiled configuration when ejected from the delivery catheter. The annuloplasty implant  301  may also comprise closed single-loop rings, such as D-shaped rings, or open single-loop rings, such as C-shaped annuloplasty rings. 
       FIG. 6 a    illustrates a method  400  for treating a defective mitral valve. The order in which the steps of the method  400  are illustrated should not be construed as limiting and it is conceivable that the order in which the steps of the method  400  is carried out may be varied. The method  400  comprises; inserting  401  a flexible and removable elongate displacement unit  101  in a delivery state into a coronary sinus CS adjacent said valve; positioning  402  a proximal expandable portion  102  against a tissue wall at the entrance of said CS; anchoring  403  a distal anchoring portion  103  comprising an inflatable unit inside the CS by expanding of the inflatable unit; activating  404  the displacement unit  101  in an activated state whereby the distal anchoring portion  103  is moved in a longitudinal direction  104  of the displacement unit  101  to reduce a distance (L) between the distal anchoring portion  103  and the proximal expandable portion  102  such that the shape of the annulus is modified to a modified shape. The method  400  comprises fixating  405  an annuloplasty implant  301  at the mitral valve annulus when said modified shape is obtained, whereby the annuloplasty implant  301  comprises a loop structure  302 , such as a helix-shaped loop structure, positioned on either side of the valve to retain the modified shape of the annulus. At least a portion of the loop structure is conformed to a curvature of the annulus. The method comprises removing  406  the elongate displacement unit  101  after temporary activation in the activated state. The method  400  thus provides for the advantageous benefits as described above in relation to the device  100  and system  200  and  FIGS. 1-5 . 
       FIG. 6 b    illustrates another flow chart of a method  400  for treating a defective mitral valve. The order in which the steps of the method  400  are illustrated should not be construed as limiting and it is conceivable that the order in which the steps of the method  400  is carried out may be varied. 
     Positioning of the proximal expandable portion  102  may comprise expanding  402 ′ bows  105  extending in the longitudinal direction  104  for apposition against the tissue wall. The method  400  may further comprise exerting  404 ′ of a force against the tissue wall in the longitudinal direction  104  towards the distal anchoring portion  103 . 
     Anchoring the distal anchoring portion  103  may comprise inflating  403 ′ the inflatable unit  103  in the great cardiac vein and/or, in the anterior interventricular branch or vein, and/or in the posterior vein and/or in the posterior ventricular vein of the heart. This provides for improving the anchoring force of the distal anchoring portion  103 . 
     The method  400  may comprise guiding  401 ′ the elongate displacement unit  101  along a guide wire  114  arranged to extend inside a lumen  109  of the elongate displacement unit  101 . The guide wire  114  may be arranged to exit the lumen at an opening  110  distally of the inflatable unit  103 . The lumen  109  may have a proximal opening  111  arranged between the inflatable unit  103  and the proximal expandable portion  102 . 
     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.