Patent Publication Number: US-11642220-B2

Title: Transcatheter valve prosthesis

Description:
This is a Continuation of application Ser. No. 15/448,071, filed Mar. 2, 2017, which in turn is a Division of application Ser. No. 14/342,237, filed Mar. 11, 2014, which issued as U.S. Pat. No. 9,662,206, which in turn is a national stage application of PCT/EP2012/061237, filed Jun. 13, 2012, which claims the benefit of U.S. Provisional Application No. 61/543,331, filed Oct. 5, 2011, and which claims the benefit of German Patent Application No. 10 2011 054 172.1, filed Oct. 4, 2011, and German Patent Application No. 10 2011 053 520.9, filed Sep. 12, 2011. The disclosure of the prior applications is hereby incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments generally relate to a transcatheter valve prosthesis, especially a transcatheter atrio-ventricular valve prosthesis. 
     BACKGROUND 
     Heart valve diseases are affecting approximately 300,000 people worldwide each year. Those diseases translate in abnormal leaflet tissue (excess tissue growth, tissue degradation/rupture, tissue hardening/calcifying), or abnormal tissue position through the cardiac cycle (i.e. annular dilation, ventricular reshaping) leading to a degrading valve function like leakage/blood backflow (valve insufficiency) or a resistance to blood forward flow (valve stenosis). 
     Accordingly, a trans catheter valve prosthesis for functional replacement of a heart valve is desirable. 
     SUMMARY 
     Various embodiments of the invention provide a trans catheter atrio-ventricular valve prosthesis for functional replacement of an atrio-ventricular heart valve in a connection channel, having a circumferential connection channel wall structure, between the atrial chamber and the ventricular chamber of a heart, comprising a radially expandable tubular body to be disposed in the interior of the connection channel and extending along an axis, and a valve arranged within and attached to the tubular body, wherein the tubular body is provided with an outer circumferential groove which is open to the radial outside of the tubular body and which defines a groove bottom, whereby the tubular body is separated by the outer circumferential groove into first and second body sections, and wherein the tubular body is provided with a first plurality of projections which extend from the first or second body section in an axial direction of the tubular body and each of which has a free end arranged to overlap the outer circumferential groove, further comprising an elongate outer member to be disposed at the exterior of the connection channel wall structure at a level of the circumferential grove, wherein the outer member can at least partially extend around the tubular body with valve tissue of the connection channel wall structure being correspondingly circumferentially arranged between the tubular body and the outer member and in such a radial distance to the axis of the tubular body that the valve tissue of the connection channel wall structure can be radially forced into the outer circumferential groove so as to be at least partially located radially below the projections. 
     Various embodiments of the invention further provide a method for implanting a transcatheter atrio-ventricular valve prosthesis comprising a tubular body having a longitudinal axis, a circumferential groove and a plurality of projections each having a free end arranged so as to partially overlap the groove, and an elongate outer member, the method comprising the steps of positioning the tubular body inside a connection channel between an atrial and a ventricular chamber of a heart, positioning the elongate outer member on an outside of the connection channel at an axial level of the circumferential groove, and fixating the prosthesis relative to the heart by reducing a distance between the elongate outer member and the tubular body so that tissue of the connection channel is inserted into the groove so as to at least partially be radially inside the projections with respect to the axis. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments are described with reference to the following drawings, in which: 
         FIG.  1    shows schematically a transcatheter valve prosthesis according to an embodiment located in a connection channel of a human heart, 
         FIG.  1   a    shows a detail of a free end of a projection of the valve prosthesis according to a variation, 
         FIG.  1   b    shows a detail of a free end of a projection of the valve prosthesis according to a variation, 
         FIG.  2    shows a transcatheter valve prosthesis according to an embodiment, 
         FIG.  2   a    schematically shows extension angles of projections according to an embodiment, 
         FIG.  3    shows schematically a transcatheter valve prosthesis comprising an elongate outer member according to an embodiment located in a connection channel of a human heart, 
         FIG.  4    shows a transcatheter valve prosthesis including a clamping member according to an embodiment, 
         FIG.  5    shows the transcatheter valve prosthesis including the damping member of  FIG.  4    from a different perspective, 
         FIG.  6   a    shows a schematic cross section of a transcatheter valve prosthesis along A-A in  FIG.  3   , 
         FIG.  6   b    shows a schematic cross section of a transcatheter valve prosthesis along B-B in  FIG.  3   , 
         FIG.  6   c    shows a schematic cross section of a transcatheter valve prosthesis along C-C in  FIG.  4    including a clamping member, 
         FIG.  6   d    shows a schematic cross section of a transcatheter valve prosthesis along C-C in  FIG.  4    including a clamping member in another arrangement than shown in  FIG.  6     c.    
         FIG.  7    schematically shows the interaction of a transcatheter valve prosthesis, heart tissue and an elongate outer member according to an embodiment, 
         FIG.  8    shows a transcatheter valve prosthesis according to an embodiment, 
         FIGS.  9   a  and  9   b    shows a tubular body of a transcatheter valve prosthesis, 
         FIGS.  10   a - 10   c    schematically show the transcatheter valve prosthesis including an outer member, and 
         FIGS.  11   a - 11   d    schematically show the transcatheter valve prosthesis including an elongate outer member according to a variation. 
     
    
    
     DESCRIPTION 
     The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. The various embodiments are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. 
     With reference to  FIGS.  1 ,  1     a ,  1   b  and  2 , a transcatheter atrio-ventricular valve prosthesis  1  for functional replacement of a (native) atrio-ventricular heart valve  5  in a connection channel  10  that connects an atrial heart chamber  15  with a ventricular chamber  20  and comprising a connection channel wall structure  25  may comprise a tubular body  30 . The tubular body  30  may be disposed in the interior of the connection channel  10  and extend along an axis  35 . The axis  35  may be the longitudinal axis  35  of the tubular body  30  which may be an elongated body. In the implanted condition, the axis  35  of the tubular body  30  may be aligned substantially coaxial to an axis of the connection channel  10 . The tubular body  30  may be radially compressible so as to facilitate approach to and insertion into the connection channel  10 , e.g. using a catheter or the like, and then be radially expandable so as to closely engage the interior or inner side of the connection channel wall structure  25 , and may comprise an artificial heart valve  40  (e.g. schematically shown in  FIG.  6   a   ) arranged within the tubular body  30 . 
     The native atrio-ventricular heart valve  5  (e.g. a mitral valve or a triscupid valve) to be replaced has the generally circumferential wall structure  25  forming the connection channel  10  or through opening between the atrial  15  and ventricular  20  chambers of the heart and including a circumferential valve annulus, valve leaflets opening and closing the connection channel/through opening and closing the connection channel  10 /through opening at a position close to the valve annulus, a generally circumferential cord structure (chordae tendinae) connected between the valve leaflets and generally circumferential papillary muscle(s), and said circumferential papillary muscle(s). 
     The artificial heart-valve  40  may be attached to the tubular body  30  and may be designed to serve as an artificial replacement valve for an atrio-ventricular heart valve (for example a mitral and/or a tricuspid valve). The artificial valve  40  may comprise artificial flaps (e.g. three flaps as schematically shown in e.g. in  FIG.  6   a   ) for functional replacement of the native heart valve. The tubular body  30  may be provided with an outer circumferential groove  45 . The outer circumferential groove  45  may be open to the radial outside of the tubular body  30 . The circumferential groove  45  may define a groove bottom  46 . The outer circumferential groove  45  may define a channel  47  which is defined itself by the groove bottom  46  and axially (in axial direction of the tubular body  30 ) opposite side walls  48 ,  49 . The groove bottom  46  may separate the tubular body  30  in first and second body sections  31 ,  32 . The circumferential groove  45  may extend around a whole circumference of the tubular body  30  or may only extend partially around a circumference of the tubular body  30 . The outer circumferential groove  45  may be a continuous that is non-interrupted groove, but may also be an interrupted groove  45  having, for example, two or more circumferential groove portions  45  provided, for example, on the same axial level of the tubular body  30  that are interrupted by areas in which no recessed portion, which may provide groove portion, is formed. The circumferential groove  45  may have an axial distance (along axis  35 ) from the axial ends of the tubular body  30 , i.e. the circumferential groove  45  may be formed spaced apart in an axial direction from end portions of the tubular body  30 . 
     As shown in  FIG.  1   , the first body section  31  may be the part of the tubular body  30  that is located above (e.g. proximal from) the circumferential groove  45 , and the second body section  32  may be the part of the tubular body  30  that is located beneath (e.g. distal from) the circumferential groove  45 . Both of the first and second body sections  31 ,  32  may have a generally cylindrical shape. According to a variation, the first body section  31  may have a conical shape along the axis of the tubular body, with its cross-section diameter increasing from the groove  45 , and the second body section  32  may be generally cylindrical. According to a variation, both of the first and second body sections  31 ,  32  may have a conical shape along the axis of the tubular body, with their respective cross-sectional diameter increasing from the groove  45 . According to variations, the cross sections (along axis  35 ) of sections  31  and/or  32  may be or contain non circular shapes but elliptical shapes or D-shaped cross sections. In addition, the direction of curvature in the axial profile (seen in a axial section along the tubular body  30 ) between the groove  45  and the first body section  31  and/or between the groove  45  and the second body section  32  may change (from concave curvature of the groove  45  to a convex curvature at the transition between groove  45  and first and/or second body section  31 ,  32 ). The axially opposite side walls  48 ,  49  of the groove  45  may be part of the first and second, respectively, body sections  31 ,  32  and may axially delimit the first and second, respectively, sections  31 ,  32  towards the channel  47  of the groove  45 , as it is shown e.g. in  FIG.  8   . A radial diameter of the first body section  31  (e.g. at an end portion that is opposite to the second body section  32 ) of the tubular body  30  may be larger than any diameter of the second body section  32 . This may allow to more efficiently fixate the prosthesis  1  in the connection channel  10  as the first body section  31  having a larger diameter may provide a better hold of the prosthesis  1  in the connection channel  10  by providing a friction and/or (mere) form fit (e.g. caused by the first body section  31  being located in the atrial chamber  15  and having a diameter larger than a diameter of the connection channel  10 ). 
     Further, the valve prosthesis  1  may comprise a first plurality of projections  50  and a second plurality of projections  55 . The projections  50 ,  55  may extend from the first and second sections  31 ,  32 , respectively, in opposite axial directions, that is they extend, at least with an extension component or an extension vector, in a direction along the axis  35  (e.g. the longitudinal axis  35 ) of the tubular body  30 . Accordingly, the first projections  50  and the second projections  55  extend generally towards each other, whereby they may not extend exactly or in line towards each other, but with an extension vector. The projections  50 ,  55  may extend substantially parallel to the axis  35  of the tubular body  30  or may also extend in a (lateral) angle γ to the axis  35  of the tubular body  30 , wherein the (lateral) angle γ extends tangential to the circumference of the tubular body  30 , as it is shown e.g. in  FIG.  2     a.    
     The valve prosthesis  1  may comprise one plurality of projections  50 ,  55  only that may extend from the first or second sections  31 ,  32  in an axial direction of the tubular body  30  and may overlap the circumferential groove  45 . With reference to e.g.  FIGS.  11   a - c   , the valve prosthesis  1  may not comprise any projections  50 ,  55  and the circumferential groove  45  may be provided with (e.g. integrally formed on) the tubular body  30 . 
     The projections of the first plurality of projections  50  each may have free ends  60 , and the projections of the second plurality of projections  55  each may have free ends  65 . The free ends  60 ,  65  of the first and the second plurality of projections  50 ,  55  may be arranged so as to overlap the outer circumferential groove  45 . That is, the free ends of the first and second plurality of projections  50 ,  55  are arranged at an axial level of the groove  45  so as to overlap the groove  45 . The first and second plurality of projections  50 ,  55  as such may at least partially or completely overlap the groove  45  along their extension. 
     The first  50  and second  55  pluralities of projections may extend in a radial distance radially outwards of the bottom  46  of the groove  45  so that a hollow (circumferential) chamber  66  is defined between the groove bottom  46  and the first and second plurality of projections  50 ,  55  in the channel  47 . The opposite side walls  48 ,  49  may further define the hollow chamber  66  in axial direction of the tubular body  30 . Hence, the hollow chamber  66  may be confined radially by the pluralities of projections  50 ,  55  and the groove bottom  46  and axially by opposite sidewalls  48 ,  49  (e.g. top- and bottom-walls) of the groove  45 . 
     A method of using a transcatheter valve prosthesis  1  may comprise positioning it in the connection channel wall structure  25  of a heart and then inserting tissue that is adjacent to the circumferential groove  45 , of the connection channel wall structure  25  into the circumferential groove  45  to be placed radially below the first and second plurality of projections  50 ,  55 . The tissue can then be held in place in the circumferential groove  45  by the first  50  and/or second plurality of projections  55 , which, if, for example, provided with acute or sharpened ends, may penetrate into the tissue which from its position below may be biased back to its initial radial position. The prosthesis  1  may be positioned such that its outer circumferential groove  45  is at the level of the annulus of the circumferential wall structure  25  or adjacent thereto towards the side of the ventricular chamber  20 . By the first and second plurality of projections  50 ,  55  keeping the tissue within the groove  45 , the transcatheter valve prosthesis  1  can be positioned and fixated relative to the heart. Further, since the first and second plurality of projections  50 ,  55  axially extend towards each other, the prosthesis is further safely and reliably prevented from being axially pushed out of the connection channel  10  by the pumping activity of the heart. The first  50  and/or the second  55  plurality of projections, may keep the tissue of the connection channel wall structure  25  in the circumferential groove  45  by perforating it (e.g. transfixing it, e.g. skewering it) and/or by an interference fit. The tissue that is held in the circumferential groove  45  may also (partially or fully) seal the transcatheter valve prosthesis  1  against the interior of the connection channel  10  so that blood, e.g. pressurized blood, can only flow through the tubular body  30  (and the artificial heart valve  40  therein) but can not bypass the tubular body  30  on its exterior side (i.e. between the exterior of the tubular body  30  and the interior of the connection channel wall structure  25 ). In this respect, the inner and/or outer circumferential surface of the tubular body  30  may additionally be provided with an impermeable layer, for example in form of a liner  33   b.    
     The prosthesis  1  may be located in the connection channel  10  so that the circumferential groove  45  is located on the ventricular side of the annulus of a natural valve, e.g. having a distance from the natural valve annulus, i.e. the circumferential groove  45  may be a sub-annular circumferential groove and/or the prosthesis  1  may be a sub-annular-prosthesis  1 . The prosthesis  1  may be adapted to be a sub-annular prosthesis, That is, the tubular body  30  may have a transverse dimension (also referred to as diameter herein) at an axial level (with respect to axis  35 ) that is smaller than a transverse dimension of a natural valve annulus and/or transverse dimension and/or axial lengths of the tubular body may be suitable so that the first body section  31  may be located in an atrial chamber  15  and that the second body section  32  may be located in the connection channel  10  with the groove  45  being located on a ventricular side of the natural valve annulus having a distance to said annulus. 
     Only one circumferential groove  45  as described above may be provided on the tubular body  30 . However, an elongated prosthesis  1  having two or more circumferential grooves  45  may be provided, wherein a respective set of first and a second plurality of projections  50 ,  55  as described above may be arranged and assigned to the respective one of the two or more grooves  45 . The groove  45  or the respective groove may be formed by the first and second body sections  31 ,  32  of the tubular body  30  as such, wherein the projections  50  and/or  55  may not be involved in forming the (respective) groove  45  as such. There may also be embodiments (see further below), in which the projections  50  and/or  55  are at least partially in forming the groove  45 , for example on the side of the tubular body  30  that is proximal to the ventricular chamber  20 . 
     The tubular body  30  may comprise or may be a mesh-type body having elongate mesh or grid elements  33  crossing each other at crossings  34 . The mesh elements  33  may be formed from wires comprising steel and/or a superalloy and/or a shape memory alloy (e.g. nitinol) and/or nickel and/or titanium and/or precious metals (e.g. gold) and/or alloys comprising the aforementioned. The mesh elements  33  may also comprise other alloys or may be made from organic material, e.g. polymers. The mesh elements  33  may e.g. be made from polyvinyl-chloride and/or polystyrene and/or polypropylene or another polymer. The tubular body  30  may be from a shape-memory material which expands when experiencing usual body temperature. The tubular body  30  may be self-expandable. The tubular body  30  may also be not self-expandable, but expandable by a balloon or another expansion mechanism. Correspondingly, the tubular body  30  may be compressible to be insertable via the catheter and may then be expandable when appropriately positioned with the connection channel wall structure  25 . The tubular body  30  may comprise the above-mentioned liner  33   b  (c.f.  FIG.  6   a   ) attached to the mesh elements  33  made from the same or made from different materials. The liner  33   b  may be disposed on an interior side or an exterior side of the mesh elements  33  and/or tubular body  30  and may cover the circumference of the tubular body  30  fully or only partially in axial direction  35  and/or in circumferential direction. 
     The circumferential groove  45  of the tubular body  30  and/or the projections of the first and/or the second plurality of projections  50 ,  55  may interact with the connection channel wall structure  25  so as to fixate the valve prosthesis  1  with respect to the channel wall structure  25  and the connection channel  10 . Tissue of the channel wall structure  25  may be “caught” in the circumferential groove  45  and be held in place by the free ends  60 ,  65  of the first and/or the second plurality of projections  50 ,  55  which may serve as hook elements. The tissue of the channel wall structure  25  may be perforated by the free ends  60 ,  65  and thereby held more firmly in the circumferential groove  45  of the tubular body  30 , wherein the tissue may also be held in the groove  45  by means of an interference and/or clamping fit between the projections  50  and/or  55  (or part thereof) and the tissue of the connection channel wall structure  25 . In order to allow the first and/or second plurality of projections  50 ,  55  to penetrate the tissue of the circumferential connection channel wall structure  25 , which has been forced into the groove, the free ends of a plurality or of each of the first  50  and/or second  55  pluralities of projections may be an acute or sharpened end. The projections of the first and/or second plurality of projections  50 ,  55  each or some thereof may be pins. 
     With further reference to  FIG.  1   b   , the free ends  60 ,  65  of the first and/or the second plurality of projections  50 ,  55  may be conical ends  70  so as to be able to perforate tissue of the connection channel wall structure  25 . According to a variation, the free ends  60 ,  65  of the first and/or the second plurality of projections  50 ,  55  may also be blunt. The free ends  60 ,  65  and/or the first and/or second plurality of projections  50 ,  55  may be pin-shaped. 
     Some or all of the free ends  60 ,  65  of the projections  55 ,  60  may comprise barbs or hooks  71  as shown in  FIG.  1   . The hooks  71  may serve to perforate tissue of the connection channel wall structure  25  and prevent the tissue from slipping off the free end  60 ,  65 . Thereby tissue that is perforated by barbs or hooks  71  disposed on a free and  60 ,  65  is unable to slip from the free end  55 ,  65  resulting in tissue from the heart valve connection channel wall structure  25  being caught even more reliably in the circumferential groove  45 . Some or all of the free ends  60 ,  65  may be blunt or may have conical ends  70  or comprise barbs or books  71 . The first  50  or second  55  plurality of projections may comprise different types of free ends  60 ,  65  according to the anatomical conditions, but may also comprise the same type of free ads  60 ,  65 . 
     The free ends  60 ,  65  and/or the first  50  and second pluralities  55  of projections may be arranged in different axial and/or radial positions and orientations with respect to each other. With reference to  FIGS.  1  and  6     a , each projection of the first plurality of projections  50  may have the same circumferential angular distance a (that is an angular distance between two radial directions extending from longitudinal axis  35  of the tubular body  30 ) from each other, i.e. the projections  50  may be equally circumferentially spaced. However, the projections of the first plurality of projections  50  may also have different angular distances a from each other, i.e. be not spaced evenly around a circumference of the tubular body. Although not shown in  FIGS.  6   a - c   , similarly, each projection of the second plurality of projections  55  may have the same angular distance from each other, i.e. be spaced equally around a circumference of the tubular body  30 . However, the projections of the second plurality of projections  55  may also have different circumferential angular distances a from each other, i.e. be not spaced evenly around a circumference of the tubular body. 
     The first plurality of projections  50  may be arranged with respect to the second plurality of projections  55  on the tubular body  30  in a way that each projection of the first plurality of projections  50  is substantially on the same radial level (that is the same radius, e.g. R 2 ) as a projection of the second, plurality of projections  55  (as it is shown e.g. in  FIGS.  1  and  3   ). On the other hand, each projection of the first plurality of projections  50  may be arranged on a different radius than a projection of the second plurality of projections  55 , wherein the first plurality of projections  50  may each be on a same radius, and wherein the second plurality of projections  55  may each be on a same radius. 
     With, for example, reference to  FIGS.  1  and  3   , the first plurality of projections  50  and the second plurality of projections  55  may extend so as to be aligned or coaxial to each other. The first plurality of projections  50  may also not be aligned with the second plurality of projections  55 , wherein the first plurality of projections  50  may themselves extend substantially parallel to each other or may not, and wherein the second plurality of projections  55  may themselves extend substantially parallel to each other or may not. 
     With, for example, reference to  FIGS.  2  and  4   , the first and second plurality of projections  50 ,  55  may be arranged in circumferential direction in an alternating manner, wherein for example each first projection  50  is circumferentially between two second projections  55  (and the other way round). There may also be other appropriate circumferential arrangement patterns for the first and second plurality of projections  50 ,  55 , wherein, for example, sets of first projections  50 , of for example one, two, three, four, or more first projections  50 , are arranged between sets of second projections  55 , of for example one, two, three, four or more second projections  50 . 
     The number of the projections of the first plurality of projections  50  and the number of projections of the second plurality of projections  55  may be, for example, in a range of three to five, or eight to ten, fifteen to twenty, thirty to hundred or more or may be any other number. The first plurality of projections  50  may comprise the same number of projections or another number of projections as the second plurality of projections  55  or vice versa. 
     The projections of the first plurality of projections  50  and/or the projections of the second plurality of projections  55  may extend from the tubular body  30  from positions, where mesh elements  33  of the tubular body  30  are crossing with each other at the crossings  34 . This may improve the mechanical stability of the interconnection of the tubular body  30  with the projections  50 ,  55 . The projections  50 ,  55  may e.g. be welded, soldered and/or braided to the tubular body  35 . They may also be sutured, bonded or glued to the tubular body  35 . As an alternative or additionally, the projections  50 ,  55  may also be monolithically integrally formed with the tubular body  30 . That is, with reference to e.g.  FIGS.  9   a  and  9   b   , the projections  50 ,  55  (or any one or both of the pluralities of projections) may be formed by mesh elements  33  that are not connected to another mesh element  33  at a crossing  34  but are projecting from the tubular body  30  (e.g. caused by bending the mesh element  33 ) in a radial and/or axial direction with respect to longitudinal axis  35  so as to form a projection  50 ,  55 . Further, projections  50 ,  55  (e.g. monolithically integrally formed by mesh elements  33  or provided separately and connected with the tubular body  30 ) may form the circumferential groove  45  by projecting radially and axially from the tubular body  30  with respect to its longitudinal axis  35 . Accordingly, by facing away from the tubular body  30 , the projections may define a circumferential groove  45  on the tubular body  30 . The circumferential groove  45  may also be further defined by a generally conical or similar shape of a body section (e.g. first body section  31  and/or second body section  32 ) of the tubular body  30  that has a cross sectional diameter that is increasing from the groove  45  in a direction of longitudinal axis  35 . As seen e.g. in  FIGS.  9   a  and  9   b   , the generally conical shape of a body section  31 ,  32  may accordingly interact with the projections  50 ,  55  which are projecting from the tubular body  30  so as to further define the circumferential groove  45 .  FIG.  9   a    shows projections  50 ,  55  that define a circumferential groove  45  by projecting first in a substantially radial direction relative to the longitudinal axis  35  and then in a substantially parallel direction to the longitudinal axis  35  when seen from the point from which the projections extend from tubular body  30 .  FIG.  9   b    shows projections  50 ,  55  that extend generally rectilinearly to define the circumferential groove  45 . The projections  50 ,  55  may be made from the same materials that were described above with reference to the tubular body  30 , e.g. super alloys, e.g. shape memory alloys (like nitinol) or steel or titanium (or alloys comprising titanium) or organic material like polymers, or the projections may be made from different material or materials. 
     As can be seen e.g. from  FIG.  8   , all or some projections of the first plurality of projections  50  and/or all or some projections of the second plurality of projections  55  may be extending in (e.g. along) a substantially straight line or in a straight line, i.e. they may not comprise any longitudinal curvature from the point from which they extend from the tubular body  30  to their respective free end  60 ,  65 , i.e. they may extend rectilinearly. They may, however, nevertheless comprise barbs or hooks  71  and/or may be pin-shaped. The first plurality of projections  50  may extend from substantially the same axial level (relating to the axial direction of the tubular body  30 ) from the tubular body  30  (e.g. shown in  FIG.  1  to  3   ) or may extend from different axial levels from the tubular body  30 . Correspondingly, the second plurality of projections  55  may extend from substantially the same axial level (relating to the axial direction of the tubular body  30 ) from the tubular body  30  (e.g. shown in  FIG.  1  to  3   ) or may extend from different axial levels from the tubular body  30 . The axial extension of the first plurality of projections  50  (axial distance (along axis  35  of tubular body  30 ) between base of projection on the tubular body and free end of projection) and/or of the second plurality of projections  55  may be substantially the same or may be different, and the extension or length of the first plurality of projections  50  and/or of the second plurality of projections  55  (distance between basis of the projection  50 ,  55  on the tubular body  30  and the free end  60 ,  65  of the projection  50 ,  55 ) may be the same or may be different. 
     In addition to the first and second plurality of projections  50 ,  55  the tubular body  30  may be provided with any other type of projection and/or collar. 
     The first  50  and the second plurality  55  of projections may extend from the first  31  and the second  32  body sections, respectively, from areas that are adjacent to or are bordering the radial outer circumference of the circumferential groove  45 . The first  50  and the second plurality  55  of projections may extend from the opposite side walls  48 ,  49  laterally defining the groove  45 . 
     Referring to  FIG.  2   , the free ends  60  of the first  50  plurality of projections may be axially spaced from the free ends  65  of the second  55  plurality of projections by an axial distance W 2  in a direction of the axis  35  of the tubular body  30 . The free ends  60  of first plurality of projections  50  may be arranged on a same axial level or on different axial levels, and the free ends  65  of the second plurality of projections  55  may be arranged on a same axial level or on different axial levels. 
     In case a transcatheter valve prosthesis  1  comprises one plurality of projections  50 ,  55 , the axial distance W 2  may define a distance of one or more or all of the free ends  60 ,  65  of the (one) plurality of projections  50 ,  55  to a sidewall  48 ,  49 , that is opposite to the respective body section  31 ,  32  the plurality of projections is extending from, of the circumferential groove  45 . 
     The projections of the first plurality of projections  50  may axially overlap with the projections of the second plurality  55  of projections with each other (not shown), wherein there may be defined an axial overlapping-distance between the free ends  60  of the first plurality of projections  50  and the free ends  65  of the second plurality of projections  55 . Some free ends  60  of the first plurality of projections  50  may be axially spaced from corresponding free ends  65  of the second plurality of projections  55 , while other free ends  60  and  65  may be arranged so as to axially overlap each other. 
     With reference, for example, to  FIG.  2   a   , the projections  50 ,  55  (each) may extend in a manner so as to be radially and inwardly inclined by an angle β, thereby obliquely extending into the outer circumferential groove  45 . The angle β defining the radial and inward inclination of the projections  50 ,  55  with respect to the axis  35  of the tubular body  30  may be an acute angle, for example in a range of equal or smaller than 45° or equal or smaller than 30°, or equal or smaller than 15°. Only a part or number of the first projections  50  and/or only a part or number of the second projections  55  may radially and inwardly inclined as above described. 
       FIG.  6   a   , which corresponds to the cross section along A-A shown in  FIG.  3   , illustrates the interaction of heart valve tissue of the connection channel wall structure  25  and the first plurality of projections  50  (a cross-section transverse the axis  35  and through the second plurality of projections  55  would result in a similar depiction as shown in  FIG.  6   a   ). The first plurality of projections  50  can be seen perforating tissue of the connection channel wall structure  25  to thereby more reliably prevent it from retracting from the tubular body  30  of the prosthesis  1 , which results in the prosthesis  1  being held more firmly in its intended place. 
     With further reference to  FIG.  3    and  FIG.  6   b   , the transcatheter atrio-ventricular valve prosthesis  1  may further comprise an elongate outer member  75 . The elongate outer member  75  may be disposed at the exterior of the connection channel wall structure  25  (i.e. e.g. in the ventricular chamber  20 ) at an axial level (e.g. with respect to axis  35 ) of the circumferential groove  45  of the tubular body  30 . The elongate outer member  75  may extend at least partially around, for example completely and continuously circumferentially around, the tubular body  30  and may be handled e.g. using a catheter member  90  that is shown schematically in  FIG.  6   b   . A radial distance R 5  between the longitudinal axis  35  and the elongate outer member  75  may be reducible or reduced so that the valve tissue of the connection channel wall structure  25  can be correspondingly at least partially forced into the outer circumferential groove  45  so as to be at least partially be located radially below the first and second plurality of projections  50 ,  55 . The radial distance R 5  may be reducible or reduced so that it is smaller than a radial distance R 4  that is defined between the longitudinal axis  35  of the tubular body  30  and the free ends  60 ,  65  of the projections  50 ,  55  (the free ends  60 ,  65  are not visible in the cross section shown in  FIG.  6   b   , but they are indicated by crosses in  FIG.  6   b   ). This means, that the elongate outer member  75  may be positioned inside the circumference defined by the first and the second plurality of projections  50 ,  55  so that tissue of the connection channel wall structure  25  is or can be located in the circumferential groove  45  between the groove bottom  46  and the first and second projections  50 ,  55 , wherein the elongate outer member  75  itself may be located inside the groove  45  between the groove bottom  46  and the first and second plurality of projections  50 ,  55 . However, the elongate outer member  75  may also be arranged to force tissue of the connection channel wall structure  25  into the circumferential groove  45  but to remain outside the groove (i.e. R 5  may be larger than R 4  as it is shown in  FIG.  6   b   ). The catheter member  90 , or an other, for example similarly structured catheter device, may be used to handle and position the elongate outer member  75  around an exterior of the circumferential connection channel wall structure  25 . 
     With further reference to  FIGS.  6   b    and  7 , the catheter member  90  may comprise a connecting means  91 , for example a cutting and clamping means, that can be used to connect free ends of the elongate member  75 , for example to out the elongate outer member  75  and clamp two ends of it together, so that the elongate member  75  may remain permanently around the tubular body  30  and thereby forms a component of the prosthesis  1 . However, the elongate outer member  75  may also merely be an interventional tool, for example as a component of catheter member, and may only be used to radially force the tissue of the connection channel wall structure  25  into the outer groove  45 , and may then be withdrawn or removed from the heart. When the elongate member  75  remains permanently positioned around an outer side of the connection channel wall structure  25 , it may permanently apply a radial and inwardly directed force to the tissue of the connection channel wall structure  25  towards the groove  45 . 
     With reference to  FIGS.  1 ,  3 ,  6     b  and  7  there may be several ways in which heart tissue of the connection channel wall structure  25  is fixated, held and/or caught in the circumferential groove  45 . The tissue may be perforated by the free ends  60 ,  65  of the first and/or the second plurality of projections  50 ,  55  e.g. via the acute ends  70  and/or the barbs or hooks  71 . The tissue may also be held in the circumferential groove  45  by an interference fit between the projections  50 ,  55 . The tissue may also be held in the circumferential groove  45  by the elongate outer member  75 . The elongate outer member  75  may be used to force the tissue into the groove  45  either temporarily (e.g. as a method step during a heart treatment) or permanently (for example, if the cutting and clamping means  91  is used to cut elongate outer member  75  and to connect its two ends together permanently while it is extending around the exterior of the connection channel wall structure  25  as shown in  FIG.  7   ). The tissue of the connection channel wall structure  25  may also be held in the circumferential groove  45  by a combination of two or more of the above described means and effects. 
     In all embodiments, the elongate outer member  75  may have a cross-sectional diameter D 1  (see e.g.  FIG.  6   b   ) that is smaller than a width W 1  of the outer circumferential groove  45  (illustrated e.g. in  FIG.  2   ). The elongate member  75  may also have a crosssectional diameter D 1  that is smaller than the gap W 2  between the free ends  60 ,  65  of the first and the second plurality of projections  50 ,  55 . The elongate member  75  may have a crosssectional diameter D 1  that is larger than width W 2  but smaller than width W 1 . The elongate member  75  may have a crosssectional diameter D 1  that is larger than width W 2  and/or width W 1 . The elongate member  75  may be a wire or a band, and may have a circular cross section or a rectangular cross section. The elongate member  75  may also have a triangular cross section or a cross section defining any other shape. The elongate member  75  may be made from any material that has been described with reference to the mesh elements  33  or a combination of those materials or other material(s). For example, the elongate member may be made from steel, a titanium alloy or a shape memory alloy such as nitinol. 
     Further, a length of the projections  50  and/or  55  may be related to the width W 1  of the circumferential groove  45 . In this respect, the ratio of a distance between the free ends  60 ,  65  of the first and second pluralities of projections  50 ,  55  (or, if only one plurality of projections  50 ,  55  is provided, a distance of the free ends  60 ,  65  of that plurality of projections  50 ,  55  to the sidewall  48 , 49  of the circumferential groove  45  that is with respect to axis  35  opposite to the projections  50 ,  55 ) to the width W 1  of the circumferential groove  45  may have a maximum value of 0.5 or 0.4 or 0.3 or 02 or 0.1. Accordingly the hollow chamber  66  may be defined between the projections  50 ,  55  and the groove bottom  46 . The width W 1  of the circumferential groove  45  may be defined between the sidewalls  48 ,  49  of the groove  45  and/or between a point from which a projection  50 ,  55  of the first and/or second plurality of projections  50 ,  55  extends from the tubular body  30  and a sidewall  48 ,  49  that is located on an opposite side of the groove ( 45 ) and/or between a point from which a projection from the first plurality of projections  50  extends and a point from which a projection form the second plurality of projections  55  extends. 
     With reference to  FIGS.  4  and  5    (for improved clarity and understanding, the transcatheter valve prosthesis  1  is shown without artificial valve  40 ), the transcatheter valve prosthesis  1  may also comprise a clamping member  80  (also referred to as a trapping member). The clamping member  80  may comprise a tubular structure having a longitudinal axis that may be arranged so as to extend in the circumferential groove  45  in a circumferential direction of the tubular body  30 . The clamping member  80  may be located in the circumferential groove  45  so as to be located (for example at least partly) radially inwards of the first and second pluralities  50 ,  55  of projections. The clamping member  80  may be in contact with the groove bottom  46  of the circumferential groove  45 . The damping member  80  may extend around a whole circumference of the tubular body  30  or only partially around the tubular body  30 , as shown e.g. in  FIGS.  4  and  5   . The clamping member  80  may extend e.g. around an angle of 10 to 30 degrees or any other angle in the circumferential groove  45 . The clamping member  80  may also extend around the whole circumference of groove  45 , e.g. around 360 degrees. The clamping member  80  may have a crosssectional diameter D 2  transverse to its longitudinal axis. The crosssectional diameter D 2  may be selectively changeable to a larger or smaller diameter D 2 , i.e. the clamping member  80  may be compressible (so as to be insertable via a catheter) and/or expandable (for example, re-expandable after being compressed) in a radial direction of its diameter D 2 , whereby the inner and outer circumferences of the clamping member are correspondingly decreased/expanded and expanded/decreased, respectively, in a radial direction of the tubular body  30  towards the first and/or the second plurality of projections  50 ,  55 . The cross sectional diameter D 2  of the clamping member  80  may be smaller than the cross sectional diameter (radius R 1  is shown e.g. in  FIG.  6   a   ) of the tubular body  30 . The clamping member  80  may be provided in order to clamp heart tissue that is located inside the circumferential groove  45  outwards in a direction from the axis  35  towards the pluralities of projections  50 ,  55 . 
     With reference to  FIG.  6   d   , the clamping member  80  may also be or form part of the above described elongate outer member  75 , wherein the clamping member  80  may then be arranged and/or guided and/or positioned (in a radially compressed condition) at the circumferential outer side of the connection channel wall structure  25  to completely or partly extend around the connection channel wall structure  25  at an axial (with respect to the axis  35  of the tubular body  30 ) level, and may then be radially expanded (in a direction of the diameter D 2  of the clamping member  80 ), whereby its inner diameter in a radial direction of the tubular member  30  then correspondingly decreases to thereby force the tissue of the inwardly arranged connection channel wall structure  25  (which is then arranged inwards of the clamping member  80 ) radially into the groove  45 . That is, the clamping member may be located between the projections  50 ,  55  and tissue of the connection channel wall structure  25 , that may be pressed into the groove  45  by an elastic force exerted by the clamping member  80  on the tissue of the connection channel wall structure  25  and a corresponding reactive force that may be exerted by the clamping member  80  on the projections  50 ,  55 . The forces that may act upon the tissue of the connection channel wall structure  25  exerted by the clamping member  80  and the groove  45  (e.g. the groove bottom  46 ) are schematically indicated by arrows  85   b . The elongate outer member  75  and/or the clamping member  80  (which may be the same member) may serve to anchor the prosthesis  1  and to seal the native heart leaflets against the prosthesis  1  against blood flow. Further, immobilization of the native leaflets by the prosthesis  1  as described herein (e.g. comprising a clamping member  80  and/or elongate member  75 ) may favour the ingrowth of heart (e.g. leaflet) tissue into the prosthesis (e.g. circumferential groove  45 ) and thereby further improve fixation of the prosthesis  1  relative to the heart and/or sealing against blood flow as the ingrown tissue may additionally or alternatively seal against blood flow on an outside of the tubular body  30 . 
       FIG.  6   c    shows a schematic cross sectional view of the tubular body  30  and the clamping member  80  similar to the cross section C-C in  FIG.  4   , however additionally showing heart tissue of the connection channel wall structure  25  that is not shown in  FIG.  4   . In  FIG.  6   c   , the positions of the first or second pluralities of projections  50 ,  55  are indicated by dots  50 ,  55 . As can be seen from  FIG.  6   c   , the heart tissue of the connection channel wall structure  25  is located inside the circumferential groove  45  radially between the groove bottom  46  of the tubular body  30  and a diameter that is defined by the free ends  60 ,  65  of the first and/or the second plurality of projections  50 ,  55 . It can be seen from  FIG.  6   c    that the clamping member  80  is elastically strained by the tissue of the connection channel wall structure  25  and in turn exerts a force that presses the tissue of the connection channel wall structure  25  against the free ends  60 ,  65 . Arrows  85  indicate the forces that are caused by the clamping member  80  and that act upon the tissue of the connection channel wall structure  25  in the groove  45 . 
     With reference e.g. to  FIGS.  6   c  and  6   d   , which show only one clamping member  80 , there may also e.g. be two or more clamping members  80  arranged in the groove  45  which are arranged in parallel to each other and/or which are arranged sequentially in a circumferential direction, with for example a circumferential distance therebetween or abutting each other, of the tubular body  30 . For example, there may be two clamping members  80  abutting each other and a third clamping member  80  that has an angular distance from the two clamping members  80  that are abutting each other may also be arranged in the groove  45 . Clamping members  80  may e.g. be positioned on diametrically opposite sides of the groove  45 . These two or more (e.g.  3  to  5 ) clamping members  80  may all have the same crosssectional diameter D 2  or may each have different crosssectional diameters. The clamping members  80  may all have the same longitudinal length or may have different longitudinal lengths (e.g. in a circumferential direction of tubular body  30 ). Clamping members  80  may be designed and arranged so that the tubular body  30  is firmly held in place according co the specific tissue structure and conditions of the connection channel wall structure  25  of a specific heart (e.g. of a patient). They may e.g. be specifically chosen and arranged by an operator or surgeon to firmly hold the tubular body  30  in place according to local conditions. The respective clamping member  80  may have an other shape than a tubular, such as a block-shape, a cubic-shape or a ball-shape. 
     The force acting on the tissue of the connection channel wall structure  25  may be increased when the clamping member  80  is used together with the elongate outer member  75  thereby further improving the connection between the transcatheter valve prosthesis  1  and the connection channel wall structure  25 . In this case, an elastic force origination form the clamping member  80  pointing from the axis  35  outwards and a force originating from the elongate outer member  75  pointing inwards to the axis  35  act upon tissue of the connection channel wall structure  25 , thereby holding the prosthesis  1  firmly in its intended position in the connection channel  10 . However, the valve prosthesis  1  may be used without the clamping member  80  and the elongate outer member  75  as well (i.e. by itself) or together with only one (anyone) of them. A prosthesis  1  not comprising a plurality of projections  50 ,  55  may be fixated by clamping member  80  and/or elongate outer member  75 , e.g. when the elongate outer member  75  and/or the clamping member  80  are/is generally rigid, e.g. when comprising or being an inflatable balloon that is filled with a substance giving it rigidity caused by a pressure or by a curing of that substance. That substance can cure with a limited amount of time, with the injection of an additional agent (eg a reticulating-agent), with application of heat or energy. It can be PMMA (Poly Methyl Methacrylate), different epoxies, polyurethane, a blend of polyurethane silicone. It can be strengthened with the addition of reinforcement fibers (eg Kevlar, carbon). 
     Clamping member  80  may be made from a mesh-type structure as shown in  FIGS.  4  and  5    and may comprise an inner lumen. The mesh may be made from metal or organic material or other material. The mesh of clamping member  80  may be made e.g. from iron, nickel, aluminium and/or titanium and/or alloys of these metals and other elements. The mesh may be made e.g. from steel (e.g. spring steel), and/or an superalloy and/or shape memory alloy (such as e.g. nitinol), Ti 6Al 4V, and/or a precious metal like gold or any combination of those and/or other materials. The mesh of clamping member  80  may also be made from polymers, e.g. from polypropylene or polyvinylchloride, Polyethylene or Nylon. Of course, the mesh may also be made from combinations of these materials, i.e. it may be made from two or more different materials. In one embodiment, the clamping member can be an expandable stent-graft made with a steel or nitinol stent covered with a Dacron or ePTFE graft. The mesh of clamping member may also or additionally comprise any material that has been described with reference to the mesh elements  33  of the tubular body  30  and/or with reference to the elongate member  75  and the clamping member  80  may be designed and a material for it may be chosen so as to create a high elastic force to press the tissue of the connection channel wall structure  25  against the projections  50 ,  55 . Clamping member  80  may also be provided with hooks or barbs to create an attachment to tubular body  30 . 
     Clamping member  80  and/or elongate outer member  75  may also comprise an inflatable inner member (not shown). The inflatable inner member may be disposed in an inner lumen of the clamping member  80  and may be inflated so as to increase diameter D 2  of clamping member  80  thereby pressing tissue of the connection channel wall structure  25  against the projections  50 ,  55  (either from an inner side if the clamping member  80  is arranged in the hollow chamber  66  or from an outer side if the clamping member  80  is initially arranged at an outer side of the connection channel wall structure  25 ). The inner member may be inflated by the operator using a tubing and fluid from an  2   g  external pressure source, e.g. a syringe, a fluid bottle or a pump located outside the body. The clamping member  80  may also be an inflatable member  80  that presses tissue of the connection channel wall structure  25  against the projections  55 ,  55  when inflated. Both the inflatable inner member and the inflatable member  80  may be made from a fluid tight, pressure resistant material, e.g. a material or polymer as described above with reference to the clamping member  80  or any other suitable material. With reference to e.g.  FIG.  11   , the inflatable member may comprise an aperture  76  (e.g. a valve, e.g. an opening) through which a substance (e.g. via a delivery tube (not shown)) may be delivered into the inflatable member or out of the inflatable member. The aperture  76  may be selectively permitting the transmission of a substance (i.e. have an “open-state”) or may be blocking the transmission of a substance (i.e. have a “closed-state”). The aperture  76  may serve to fill the inflatable member or to un-fill (e.g. to empty) the inflatable member in order to change a crosssectional diameter of the inflatable member. The clamping member  80  and/or the elongate outer member  75  may be made of an elastic material (e.g. a polymer and/or a metal) and/or may be filled with an compressible (e.g. elastical) substance (e.g. a gas and/or a foam material and/or a hydrogel) to provide a damping/cushioning functionality. A substance for filling the inflatable member may be a gas, a liquid or any other substance and/or may be a substance that changes its phase (e.g. gas, liquid, solid) when in the inflatable member (the substance may e.g. change from liquid phase to a generally solid phase). The substance may be a substance that is capable of curing and/or hardening when disposed in the inflatable member so as to provide a generally rigid clamping member  80  and/or elongate outer member  75 . 
     Clamping member  80  may apply a force to the opposite side walls  48 ,  49  of groove  45 , for instance upon radial expansion relatively to its longitudinal axis. This force may increase or decrease the distance between body sections  31  and  32  and/or the distance between axial ends (with respect to axis  35 ) of the tubular body  30 . Tubular body  30  may be made to be elastic (e.g. comprising a mesh structure and/or an elastic material). The force exerted by clamping member  80  may also result in a expansion or reduction of a perimeter of the groove bottom  46  along a circumference of groove  45  and/or in an expansion or reduction of diameter R 1  of the tubular body  30  at an axial height (with respect to axis  35 ) of groove  45  respectively. The clamping member  80  and/or the elongate outer member  75  (which may be the same member or may be separate members) may also not produce a force in a radial direction and/or a longitudinal direction of the tubular body  30  with respect to its longitudinal axis  35 . Accordingly, the clamping member  80  and/or the elongate outer member  75  may act as a displacement member by displacing tissue of the connection channel  10  without exerting a clamping force to the tubular body  30  but by providing a mere interference fit between the circumferential wall structure  25  of the connection channel  10 , the clamping member  80  and/or the tubular body  30  in addition or as alternative to e.g. tissue being pierced by projections of the first  50  and/or second plurality of projections  55 . 
     The clamping member  80  and/or elongate outer member  75  may be located only partially radially inwards of the first  50  and/or second  55  plurality of projections and may be located so as to be pierced by anyone or both pluralities of projections so as to be held relative to the tubular body  30 . The elongate outer member  75  and/or clamping member  80  may be pierced by only one plurality of projections  50 ,  55  and the other plurality of projections may not pierce the clamping member  80 /elongate outer member  75  (or, the other plurality of projections may not be provided in case of a prosthesis  1  only comprising one (a) plurality of projections (on on side of the groove  45 )). The plurality of projections  50  and/or  55  may be piercing the clamping-member  80  so that the respective free ends  60 ,  65  of the projections  50 ,  55  end inside the clamping member  80  or so that the free ends  60 ,  65  of the respective projections  50 ,  55  are penetrating through the clamping member  80  and exit from the clamping member so that the respective free ends  60 ,  65  may be located outside the clamping member  80 . 
     With reference to  FIG.  10   b   , the elongate outer member  75  and/or the clamping member  80  may also be provided in the groove  45  radially inwards of the projections  50 ,  55  so that the elongate outer member  75  and/or the clamping member  80  is not pierced by the projections  50 ,  55 . The elongate outer member  75 /clamping member  80  may be held by a mere interference fit or a frictional/interference-fit between the groove  45 , the tissue of the connection channel wall structure  25  and/or projections  50 ,  55  in the groove  45  (e.g. when inflated, e.g. when expanded). Further, as schematically shown in  FIG.  10   b   , the elongate outer member  75 /clamping member  80  may have a cross sectional shape that is substantially elliptical or has any other shape, such as a triangular, rectangular or polygonal shape. The substantially elliptical shape of the elongate outer member  75 /clamping member  80  that is shown in  FIG.  10   b    may be caused by the design of the elongate outer member  75 /clamping member  80 , e.g. when it is provided with a tubular structure having a substantially elliptical shape (e.g. when expanded), or it may be caused by anisotropic forces acting upon elongate outer member  75 /clamping member  80  caused e.g. by the projections  50 ,  55 , the tissue of the circumferential wall structure  25  and/or groove  45 . That is, the elongate outer member  75 /clamping member  80  may have a substantially round cross section when no external forces act upon it and may be assuming a different shape (e.g. elliptical), when implanted (and, e.g. expanded). 
     With reference to e.g.  FIG.  10   c   , an expandable and/or reducible elongate outer member  75  (e.g. clamping member  80 ) may have a diameter D 2  that may be larger than width W 1  of circumferential groove  45  when expanded so that the elongate outer member  75  may extend out of the groove  45  and may occupy a space between the circumferential wall structure  25  and tissue forming a heart chamber (e.g. the ventricular chamber  20  and/or atrial chamber  15 ), i.e. the elongate outer member  75  may form a shape arranged between (e.g. abutting) the connection channel wall structure  25  and tissue/muscles of a heart chamber wall (e.g. of ventricular chamber  20 ) when expanded (e.g. fully expanded). Accordingly, the elongate outer member  75  may be located (e.g. partially, e.g. a part thereof) radially outside (with respect to axis  35 ) the circumferential groove  45  and may extend parallel to axis  35  along one or both body sections  31 ,  32  (e.g. along second body section  32 ) of tubular body  30  while being (e.g. partially, e.g. a part of elongate outer member  75 ) located radially outside groove ( 45 ). Accordingly, the elongate member  75  may comprise an angularly shaped (e.g. substantially describing an angle of about 90°) cross section with a first angular leg  75   a  that may be extending with respect to axis  35  generally radially into the groove  45 , and a second angular leg  75   b  that may be extending generally parallel to axis  35  of the tubular body  30  on an outside of the tubular body  30  (e.g. along first body section  31  and/or second body section  32 ). That is, the elongate outer member  75  (e.g. second angular leg  75   b  thereof) may be disposed between the first  31  and/or second  32  body section and tissue/muscle forming a wall of a heart chamber such as the ventricular chamber  20  and/or atrial chamber  15 . While in  FIG.  10   a - c    the elongate outer member  75 /clamping member  80  is only shown on one side of the prosthesis  1 , it may also extend fully or partially (as shown e.g. in  FIG.  11   a - d   ) around the prosthesis  1  (e.g. the circumferential groove  45 ). The elongate outer member  75 /clamping member  80  may comprise free ends  77 ,  78  (e.g. two free ends  77 ,  78 ) in a direction of a central-longitudinal axis that may be non-connected and/or not abutting each other, i.e. spaced away from each other. The free ends  77 ,  78  may have an angular distance from each other (e.g. in the groove  45 , e.g. when inflated in the groove  45 ) defined by an angle of e.g. less than 180°, less than 90, less than 45° or less than 10° with respect to axis  35 . The aperture  76  may be provided on one of these free ends  77 ,  78  or a an aperture  76  may be provided on each of the free ends  77 ,  78 . When the elongate outer member  75 /clamping member  80  only extends partially around circumferential groove  45  and accordingly comprises free ends, it may have a rigidity caused by a substance, e.g. by a curing substance (that may be cured). 
     Accordingly, the clamping member  80 /elongate outer member  75  (e.g. when it comprises an elastic and/or compressible material, e.g. as described above) may serve to dampen movement of the heart (e.g. caused by the beating heart, e.g. pulse) by acting as a dampening and/or cushioning member between the heart (e.g. a heart chamber) and the prosthesis  1  (e.g. tubular body  30 ) to further improve the fixation of the prosthesis  1  relative in the heart by reducing forces caused by the beating heart acting on the prosthesis  1  by dampening these forces. Accordingly, the clamping member  80 /elongate outer member  75  may absorb movements (e.g. of the ventricular wall (e.g. of the papillary muscle of the ventricular chamber  20 ) to avoid pulsation of the prosthesis  1 . The clamping member  80  may serve to maintain a distance of the prosthesis  1  from tissue of the heart (e.g. from a wall of the ventricular chamber  20  and/or the atrial chamber  15 ) and thereby improve placement and/or fixation of the prosthesis  1 . Accordingly, the elongate outer member  75  and/or the clamping member  80  may serve as a damping member and/or a spacer member. The clamping member  80  and/or the elongate outer member  75  and hence, the groove  45 , may be arranged on a side of the ventricular chamber when seen from the annulus of the natural valve having a distance from the annulus. 
     The shape of a cross section of tubular body  30  across its longitudinal axis (e.g. axis  35 ) may be modified. Catheter member  90  may comprise or provide a piercing component that can be positioned through the connection channel wall structure  25  (e.g. from an outside of connection channel wall structure  25 ) and through the tubular body  30  in substantially diametrically positions relatively to an axial (with respect to axis  35 ) cross section. The piercing component may be hollow and enable placement of an anchor on connection channel wall structure  25  at the distal position of a diameter of the connection channel wall structure  25  relatively to catheter member  90 . Said anchor may be attached to a longitudinal end of a longitudinal component (e.g. a tether) which in turn may be provided with a second anchor on its other longitudinal end. The second anchor may be placed by the piercing component upon retrieval of the piercing component form the connection channel wall structure  25  at the proximal end (relatively to catheter member  90 ) of said diameter on connection channel wall structure  25 . The length of said longitudinal component can be designed to be under tension from forces acting on the longitudinal component induced by the first and second anchors, so as to create a deformation of tubular body  30  in a substantially elliptical shape, e.g. the longitudinal component may be shorter than a diameter of the tubular body  30  when no external forces act upon tubular body  30 . The longitudinal component may be placed across an inner lumen of tubular body  30  in a position where it does not interfere with the function of valve  40 , e.g. be geometrically spaced away from the valve  40 . It may also be small enough to avoid significant interference with blood flow through tubular body  30 , e.g. may have a radius or a diameter ranging from 100 μm to 1000 μm. 
     All embodiments of the transcatheter valve prosthesis  1  may comprise positioning and/or orientation devices to facilitate relative and/or absolute positioning of the tubular body  30  and/or the elongate-outer member  75  and/or the clamping member  80 . These devices may include passive markers that am fixedly attached to the tubular body  30  and/or the elongate outer member  75  and/or the clamping member  80 . The passive markers may be made from materials different from the materials of the tubular body  30  and/or the elongate outer member  75  and/or the clamping member  80  in order to improve contrast during medical imaging, e.g. using magnetic resonance or X-ray based imaging techniques. The passive markers may e.g. be made of highly radio-opaque materials thereby allowing to precisely acquire the relative and/or absolute position of the components of the transcatheter valve prosthesis  1  with respect to the body. The passive markers may each have an asymmetrical shape so as to allow identifying the absolute and/or relative position and orientation and thereby the position and orientation of the tubular body  30  and/or the elongate outer member  75  and/or the clamping member  80 . The passive markers may also have an identical shape and may be arranged in a certain configuration relative to each other to allow recognition of the orientation. The circumferential groove  45  of the tubular body  30  and/or the tubular body  30  and/or the elongate outer member  75  and/or the clamping member  80  may have passive markers fixedly attached to facilitate positioning them relative to each other using imaging techniques, e.g. passive markers made of highly radio-opaque materials when imaging techniques based on electro-magnetic radiation (e.g. X-ray imaging) are used. In addition and/or as an alternative, the circumferential groove  45  and/or other parts/components of the tubular body  30  and/or the elongate outer member  75  and/or the clamping member  80  may be made from radio-opaque materials. 
     A method for using a transcatheter prosthesis  1  as described above may comprise:
         Placing the transcatheter valve prosthesis  1  within an atrio-ventricular valve, e.g. in a mitral or a tricuspid valve of a human or animal heart, via an insertion catheter. The transcatheter valve prosthesis  1  may e.g. be placed in a connection channel wall structure  25  between a ventricular chamber  20  and an atrial chamber  15  as shown in  FIG.  1   .       

     To place transcatheter valve prosthesis  1  within the heart valve, the following approaches may be applied: 1) an arterial retrograde approach entering the heart cavity over the aorta, 2) through a venous access and through a puncture through the inter atrial septum (trans-septal approach), 3) over a puncture through the apex of the heart (trans-apical approach), 4) over a puncture through the atrial wall from outside the heart, 5) arterial access (e.g. the femoral artery through a puncture in the groin) or 6) any other approach known to a skilled person. The approach to the valve is facilitated as the tubular body  30  is radially compressible and extendable and may e.g. be folded and stuffed in a catheter during approach and may be unfolded/extended when being within the circumferential connection channel wall structure  25 . The transcatheter valve prosthesis  1  may include the clamping member  80  or the clamping member  80  may be inserted separately via one of the mentioned approaches (e.g. using a catheter) so as to be placed in the circumferential groove  45  of the tubular body  30  when the tubular body  30  is located in the connection channel wall structure  25 . The clamping member  80  may be compressible and expandable.
         Fixating the transcatheter valve prosthesis  1  in the heart relative to the valve.       

     For functional replacement of a heart valve, the transcatheter valve prosthesis  1  is fixated relative to the connection channel wall structure  25  and sealed against blood flow on the exterior of the transcatheter valve prosthesis  1  in the connection channel wall structure  25 . To achieve this, tissue of the connection channel wall structure  25  adjacent to the circumferential groove  45  may be forced or placed inside the circumferential groove  45  to engage radially below the first  50  and second  55  pluralities of projections whereby the tissue is prevented from slipping out of the groove  45  by the first  50  and/or second  55  plurality of projections, wherein the free ends  60 ,  65  of the first  50  and/or second plurality  55  of projections may penetrate the tissue. The tissue of the connection channel wall structure  25  may be (completely) perforated, or example partially perforated, by the projections  50 ,  55  and may thereby be prevented from slipping out of the circumferential groove  45 . The clamping member  80  or two or more clamping members  80  may be provided in the circumferential groove  45  to actively press tissue of the connection channel wall structure  25  against the free ends  60 , 65  so as to interlock the tissue with the free ends  60 ,  65 . This results in the transcatheter valve prosthesis  1  being held in place more firmly and sealed against blood flow between the exterior of the tubular body  30  and the connection channel wall structure  25 . 
     To place tissue in the circumferential groove  45  of the tubular body  30 , a method for using a transcatheter valve prosthesis  1  may comprise using an elongate outer member  75  to radially and inwardly force tissue of the connection channel wall structure  25  into the circumferential groove  45  (which may or may not comprise a clamping member  80 ). With reference to  FIG.  3   , the elongate outer member  75  may be disposed at an exterior of the connection channel wall structure  25  at a level of the circumferential groove  45 . Then, with further reference to  FIG.  6   b   , a distance R 5  between the elongate outer member  75  and the axis  35  of the tubular body is reduced (that means that also a distance between the bottom  46  of the circumferential groove  45  of the tubular body  30  and the elongate outer member  75  is reduced) so as to force tissue of the connection channel wall structure  25  into the circumferential groove  45  to fixate the tissue in the circumferential groove  45 . The elongate outer member  75  may be handled via a catheter member  90  and an approach as described in relation to the transcatheter valve prosthesis  1  or any other approach may be used in order to bring the elongate outer member  75  in the vicinity of the connection channel wall structure  25 . When the tissue of the connection channel wall structure  25  is held in the circumferential groove  45  by the projections  50 ,  55 , the elongated member  75  (and the catheter member  90 ) may be removed from the heart or, as shown illustratively in  FIG.  7   , the connecting means  91  of the catheter member  90  may be used in order to permanently connect two (free) ends of the elongate outer member  75  together and cut the ends so that elongate outer member  75  remains permanently on the exterior of a connection channel wall structure  25  on a level of the circumferential groove  45  of the tubular body  30  so as to additionally hold tissue of the connection channel wall structure  25  in the circumferential groove  45 . 
     A method for using the transcatheter atrio-ventricular prosthesis  1  may result in the transcatheter valve prosthesis  1  being fixated to the connection channel wall structure  25  and being firmly held in place via the tissue that is held in the circumferential groove  45  by the free ends  60 ,  65 , optionally supported by the clamping member  80  and/or the permanently disposed elongate outer member  75 . 
     Features of the transcatheter atrio-ventricular valve prosthesis  1  and method steps involving the prosthesis that have been described herein (description and/or figures and/or claims) referring to a transcatheter atrio-ventricular valve prosthesis  1  comprising first  50  and second  55  pluralities of projections also apply to a transcatheter atrio-ventricular valve prosthesis  1  comprising one plurality of projections ( 50 ,  55 ) and vice versa. In particular, features described in the application (description, claims, figures) to further define the projections of the first and second plurality of projections are also applicable to only the first plurality of projections if, for example, the valve prosthesis only comprises the first plurality of projections (as it is, for example, the case in claim  1 ). All features herein are disclosed to be interchangeable between all embodiments of the transcatheter atrio-ventricular valve prosthesis  1 .