Patent Description:
The invention relates to atrio-ventricular valve (mitral valve or tricuspid valve) replacement devices for functionally replacing the corresponding native atrio-ventricular valve, and, in more detail, to a transcatheter atrio-ventricular valve replacement device or transcatheter atrio-ventricular valve prosthesis which allows implantation by means of a percutaneous approach, that is, a minimal invasive approach on a beating heart.

Normally the mitral valve allows blood to flow freely from the left atrial chamber to the left ventricular chamber during diastole when the heart is relaxed and prevents the backflow of blood from the left ventricle to the left atrium during systole when the heart contracts. The mitral valve or mitral valve structure has a generally circumferential wall structure forming a connection channel or through opening between the atrial and ventricular chambers of the heart and including a circumferential valve annulus, valve leaflets opening and closing the connection channel/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).

Proper opening and closing of the mitral valve leaflets depends on the coordinated function of its individual components i.e., the mitral annulus, the anterior and posterior mitral valve leaflets, chordae tendineae, papillary muscles, and the left atrial and left ventricular (LV) walls in continuity with the leaflets, and papillary muscles, respectively.

Mitral valve disease can take the form of mitral stenosis or mitral regurgitation. Mitral stenosis results when the valve does not open fully during diastole. In this case, higher than normal pressures are required to push blood forward into the left ventricle. Mitral regurgitation (MR) is a condition whereby the mitral valve does not close properly when the left ventricle contracts during left ventricular contraction. As a result, there is abnormal leaking of blood from the left ventricle into the left atrium.

Mitral pathology may basically be treated by valve repair or valve replacement. The treatment of mitral stenosis was revolutionized in <NUM> and <NUM> when Inoue and Lock developed percutaneous mitral balloon valvotomy. Echocardiography is essential for patient screening and predicting the likelihood of a successful percutaneous balloon mitral valvotomy (PBMV). Nevertheless, predicting the outcome of percutaneous mitral balloon valvotomy remains somewhat limited. In cases where the mitral valve leaflets are severely restricted, thickened, and/or calcified and the submitral apparatus is severely thickened and/or calcified, surgical mitral valve replacement or repair needs to be considered. Mitral valve surgery is also indicated in patients with concomitant moderate to severe mitral regurgitation or left atrial thrombus. Although there is some data comparing the outcomes of PBMV to surgical commissurotomy for patients with mitral stenosis, there is a paucity of data comparing the outcomes of PBMV to surgical mitral valve replacement. The outcomes of PBMV were just as good or better than surgical commissurotomy in patients who were candidates for PBMV.

Mitral regurgitation can result from an abnormality of the mitral valve leaflets or chordae tendinae, in which case it is called primary or degenerative mitral valve disease. On the other hand, mitral regurgitation can occur in the setting of normal mitral valve leaflets and chordae tendinae; known as secondary or functional mitral regurgitation. In this case, a dilated left ventricle from ischemic or non-ischemic origin can result in mitral annular dilatation or a change in position of the papillary muscles and lead to abnormal closing of the mitral valve leaflets.

Mitral regurgitation is an important health problem. It affects approximately <NUM>% of the population above <NUM> years old. Of the <NUM> million patients suffering from heart failure in the United States, <NUM>-<NUM>% are found to have moderate to severe mitral regurgitation. The occurrence of mitral regurgitation early after a myocardial infarction (MI) is reported to be <NUM>% (mild in <NUM>%, moderate-severe in <NUM>%). Short- and long-term survival is worse when mitral regurgitation of any severity accompanies heart failure or a myocardial infarction.

Although surgical mitral valve repair or replacement remains the standard of care for patients with significant mitral valve disease, the European Heart Survey demonstrated that up to one-half of patients with severe symptomatic mitral regurgitation do not undergo surgery. Compared with those who underwent surgery, these patients were typically older, had impairment of left ventricular function, and had more noncardiac diseases than did patients undergoing valve surgery. Whether denying surgery in these patients was justified or not, the challenges of managing these patients will only increase in the coming years as the number of patients considered for surgery continues to rise.

Although surgical mitral valve repair and replacement can be associated with an acceptable mortality risk approaching <NUM>% and <NUM>%, respectively, it requires a sternotomy and cardiopulmonary bypass that can be associated with significant complications. More specifically, the occurrence of any major complication (e.g. operative mortality, myocardial infarction, tamponade, septicemia, stroke, re-operation, renal failure, deep wound infection, ventilatory support > <NUM> hours and GI bleed ) can be as high as <NUM>% and <NUM>% for mitral valve repair and replacement, respectively (STS database <NUM>).

Previous data published from the mid <NUM>'s suggested that surgical mitral valve repair had better short- and long-term survival chances than mitral valve replacement (<NPL>). It is important to note that the Starr Edwards valve was the most frequently utilized mechanical valve in that study. Since then, there has been a better understanding of the techniques for surgical mitral valve replacement. For instance, preservation of the chords and maintaining the submitral apparatus intact during mitral valve replacement has been associated with improved indices of left ventricular end systolic function (<NPL>). In addition, the use of bioprosthetic over mechanical mitral valves has been shown to reduce the incidence of valve-related complications such as bleeding (<NPL>). In a propensity-matched analysis, the probability of re-operation was higher after mitral valve repair than mitral valve replacement.

Mitral valve annuloplasty is the cornerstone of mitral valve repair. Annuloplasty may be used together with leaflet repair (resection, sliding annuloplasty) or chordal reconstruction (transposition, artificial chords). For repair of a degenerative mitral valve, failure to include an annuloplasty procedure negatively affects the long-term results of the procedure.

The Alfieri procedure involves suturing the free edges of the middle anterior and middle posterior leaflets of the mitral valve. This produces a double orifice mitral valve. The procedure can be used to treat degenerative or functional mitral regurgitation. Like leaflet repair, the Alfieri procedure requires concomitant annuloplasty to avoid repair failure.

The clinical benefits and durability of mitral valve repair in the setting of severe functional mitral regurgitation are controversial; especially in the setting of severe left ventricular dilatation and dysfunction (<NPL>) (<NPL>) (<NPL>) (<NPL>). Furthermore, the respective role of mitral valve repair and replacement in this setting is also unclear. Although mitral valve replacement with chordal preservation is associated with a higher operative mortality than mitral valve repair, replacement offers a significantly lower failure rate. The failure rate of mitral valve repair for secondary mitral regurgitation can be as high as <NUM>% at <NUM>-<NUM> years follow-up. Most of the literature pertaining to secondary mitral regurgitation and surgical therapy is based on mitral valve repair rather than mitral valve replacement. It can be hypothesized that the lack of mortality benefit associated with mitral valve repair is in some ways related to the poor durability results with mitral valve repair than mitral valve replacement.

In an effort to address the challenges ahead, researchers have been developing new options for a rapidly growing pool of patients in whom heart valve replacement or repair may be beneficial, but for whom surgical intervention is considered too high risk.

The goal of transcatheter valve therapy is to provide a treatment modality that is less invasive, associated with equal or greater efficacy compared with standard surgery, and is potentially safer compared to more invasive procedures.

To overcome the limitations of surgical mitral valve implantation, several techniques have been proposed for minimally invasive or endovascular valve implantation in the mitral and/or tricuspid position.

Most catheter delivered devices are based on stents to enable collapsation and reexpansion, anchoring and sealing contact with the anatomy. Stents, whether balloon- or self-expandable, anchor by inner radial force on the anatomy. However the atrio-ventricular heart valves do not offer a substantially cylindrical location like a vessel or an aortic or pulmonary valve. Consequently anchoring by inner radial force is unstable. Furthermore, the valve annulus usually is very supple and extends significantly under inner radial force which can be deleterious to the anchoring and to the heart function. In addition the size and shape of the mitral valve annulus varies considerably in diseased valves. Therefore many different diameters for prosthetic replacement devices would be necessary.

Several authors have described alternative ways to anchor a valve prosthesis in the atrio-ventricular position. Some rely on a specific shape enabling a firm anchoring without the need of inner radial force like <CIT>) describing a cage like construction filling the atrium and enabling to rest on the atrial wall over its complete surface. However, this technique will considerably impair atrial function, because atrial contraction is impeded. <CIT>) and<CIT>) suggested the use of hooks engaging the valve annulus. <CIT>) described both a specific shape and a tether that can be anchored in the ventricular wall to resist dislodgment. Likewise <CIT> describe a prosthesis which is anchored by broad extensions in the left atrium and held in place by countertraction through fixation in the left ventricular apex. In contrast <CIT>) describe a prosthesis which is anchored on the ventricular side of the mitral valve and held in place by countertraction through the left atrial wall. Both <CIT>) and <CIT>) suggest a prosthesis which is fixed in the mitral valve annulus by radial force, supported by some longitudinal compression through atrial and ventricular extensions. A different approach is presented by<CIT>) who describe a two double barrel stent design, fixed in the mitral annulus by radial force.

While those authors describe means to achieve anchoring of a collapsible valve device, there is no clear description on how they achieve sealing contact to avoid peri-prosthetic leakages. Furthermore there is no mention on how the prosthesis can accommodate different ring sizes and shapes.

Furthermore, to avoid pushing the anterior mitral leaflet in the outflow tract and obstructing the bloodflow out of the ventricle, such authors describe specific requirements. Quadri`s device is anchored on the annulus and it does not reach inside the ventricle between the mitral leaflets but rather protrudes proximally inside the left atrium creating a no-flow zone and the risk of thrombus. Part of the free floating anterior leaflet which is not fixed by the hooks on the ventricular side of the stent may even protrude into the left ventricular outflow tract causing SAM. Rowe's device requires a distal end smaller than the proximal end.

All of the devices described above share the same potentially unresolved issues.

Further to the above, <CIT> discloses methods, apparatus, and systems used to deliver a prosthetic heart valve to a deficient valve, wherein a support stent is delivered to a position on the surface of the outflow side of a native heart valve of a patient, the support stent defining a support-stent interior, wherein an expandable prosthetic heart valve is delivered into the native heart valve from the inflow side of the native heart valve and into the support-stent interior, wherein the expandable prosthetic heart valve is expanded while the expandable prosthetic valve is in the support-stent interior and while the support stent is at the position on the surface of the outflow side of the heart valve, thereby causing one or more of the native leaflets of the native heart valve to be frictionally secured between the support stent and the expanded prosthetic heart valve.

Further methods, apparatus, and systems are disclosed by <CIT>, <CIT> and <CIT>.

The claimed invention is set out in independent claim <NUM> and provides a transcatheter atrio-ventricular valve prosthesis for functional replacement of an atrio-ventricular valve in a connection channel. Further advantageous embodiments are described in the dependent claims.

Exemplary techniques and apparatuses, including prostheses, for practicing embodiments of the invention are shown in the attached figures and the descriptive appearing thereon. The features described herein can be used in various combinations, which are intended to be encompassed hereby. The disclosure of the embodiments as disclosed herein is not intended to restrict the invention to those specific embodiments, but to encompass all embodiments of the concepts addressed herein, as defined by the appended claims.

In the figures, the same reference signs are used to identify same and similar parts and elements.

Implantation of a transcatheter atrio-ventricular valve prosthesis (mitral valve or tricuspid valve prosthesis) on a beating heart can be achieved by a minimally invasive approach in a mammal. This specification describes procedures and apparatuses, including the valve prosthesis itself, to insert and deploy the valve prosthesis and to anchor it by attachment to locations inside the heart.

According to an embodiment, the invention provides a transcatheter atrio-ventricular valve prosthesis. The disclosure provides a method for implanting a transcatheter atrio-ventricular valve prosthesis. Further embodiments are described below.

According to an embodiment of the invention, a transcatheter atrio-ventricular valve prosthesis for functional replacement of an atrio-ventricular valve in a connection channel, having a circumferential connection channel wall structure, between atrial and ventricular chambers of a heart is provided, comprising an inner device to be disposed in the interior of the connection channel, the inner device having a circumferential support structure or circumferential support body which is radially expandable and having a valve attached to the circumferential support structure, and an outer device to be disposed on the exterior side of the connection channel, wherein the outer device at least partly extends around (circumferentially around) the inner device in a radial distance to the inner device, wherein the inner device, for example the circumferential support structure of the inner device, and the outer device form a clamping mechanism for clamping the circumferential connection channel wall structure of the connection channel therebetween.

The circumferential support structure defines an inner channel or inner through opening forming a replacement channel for functionally replacing or re-enforcing the (native) connection channel between the atrial chamber and the ventricular chamber. In the implanted condition, the circumferentially support structure, for example, circumferentially and continuously abuts the inner periphery of the circumferential connection channel wall structure. The (new) valve is fixedly arranged in the interior of the circumferential support structure and, thus, within said replacement channel, and is fixedly attached to the circumferential support structure so as to be able to take over and correspondingly replace the function of the native valve, that is, so as to be able to appropriately open and close the replacement channel to appropriately allow blood flow therethrough between the atrial chamber and the ventricular chamber, between which it is (or is to be) implanted.

According to another embodiment of the invention, a transcatheter atrio-ventricular valve prosthesis for functional replacement of an atrio-ventricular valve in a connection channel, having a circumferential connection channel wall structure, between the atrial chamber and the ventricular chamber of a heart is provided, comprising an inner device to be disposed in the interior of the connection channel, the inner device having a circumferential support structure which is radially expandable, and having a valve attached to the circumferential support structure, wherein the circumferential support structure of the inner device is of tubular shape and extends along an axis and has two axial ends, and an outer device to be disposed on the exterior of the connection channel, wherein the outer device at least partly extends around the inner device in a radial distance to the inner device, and wherein the inner and outer devices form a clamping mechanism for clamping the circumferential connection channel wall structure therebetween, wherein the outer device comprises a ring, for extending circumferentially around the circumferential connection channel wall structure, arranged between and in a distance to the axial ends of the inner device, wherein the outer device further comprises an anchor member having one or more anchor parts, such as one or more barbs and/or one or more hooks, to penetrate into the circumferential connection channel wall structure at a position at or close to the ring, the anchor member comprising an eye, through which the ring extends to thereby be anchored on the circumferential connection channel wall structure at this position by the anchor member.

The (native) connection channel between the native arterial and ventricular chambers (which may be the left chambers in case of (functional) mitral valve replacement or right chambers in case of (functional) tricuspid valve replacement) is defined by the circumferential and/or peripheral connection channel wall structure provided by (the tissue of) the native valve leaflets, the native valve annulus of the native atrial-ventricular valve and, in an embodiment, may also be the adjacent muscular tissue, the generally circumferential cord structure (chordae tendinae) between the valve leaflets and the generally circumferential papillary muscle(s), and said papillary muscle(s), wherein the inner and outer devices are provided such as to (at least partly) circumferentially clamp said connection channel wall structure therebetween. In the area of the native valve leaflets and the native valve annulus, the circumferential connection channel wall structure forms a substantially closed circumferential connection channel wall, and in the area of the chordae tendinae the circumferential connection channel wall structure forms a longitudinally slotted and, hence, more radially opened circumferential wall structure. The inner device is, for example, to be arranged within the circumferential connection channel wall (formed by the valve annulus and the leaflets), thereby achieving an improved sealing and fixation function. Also the outer device is, for example, to be arranged around the mentioned circumferential connection channel wall (formed by the valve annulus and the valve leaflets), and/or the outer device may also be arranged around the circumferential connection channel wall structure in the area of the chordae tendinae and/or in the area of the papillary muscle(s) in as far as the inner device extends into between these/this area(s). According to a further extended approach, part of the respective atrium, for example that part of the respective atrium which is adjacent to the corresponding atrio-ventricular valve to be functionally replaced, may be considered to also form part of the corresponding connection channel so that according to this extended approach the (native) circumferential connection channel wall structure which is to be clamped between the outer and inner devices is formed by a part of the corresponding atrium wall. In this respect, the outer device may also be arranged around the corresponding atrium.

The transcatheter atrio-ventricular valve prosthesis is preferably collapsible to fit inside a delivery catheter and re-expandable to be functional inside the heart cavity. In this respect, the circumferential support structure of the inner device can be brought in a collapsed condition to be then implanted in percutaneous manner, and can then be expanded when being in its final implanted position within the (native) connection channel. The circumferential support structure can be a stent-like component, and can be, for example, self expandable or balloon expandable. It can be made of nitinol or stainless steel or any material enabling properties desired for the application (biocompatibility, elasticity, yield strength, fatigue resistance, corrosion resistance). It can be laser-cut or assembled from a wire, or produced by other methods. For example, the circumferential support structure can be formed by a mesh-like wire structure of either a shape-memory material, such as nitinol, thereby forming a self-expandable mesh structure, or of a non-shape-memory material, such as stainless steel, thereby forming a non-self-expandable mesh structure which has to be expanded by an additional or separate expanding means, such as by an internal and expandable balloon which is inserted into an interior of the initially collapsed circumferential support structure and which can be inflated and deflated to expand the circumferential support structure and to be then removed therefrom, respectively.

Further, the circumferential support structure is, for example, of a tubular shape (for example, of a tubular mesh shape) which is collapsible and re-expandable to its tubular shape.

The expandability and corresponding collapsibility of the circumferential support structure (the valve attached thereto is correspondingly collapsible and deployable) allows delivery of the inner device by means of a catheter forwarded to the atrio-ventricular valve, for example, via the corresponding atrial chamber or ventricular chamber.

The outer device can also be forwarded by means of a catheter to the atrio-ventricular valve, for example via the atrial chamber or the ventricular chamber, wherein the inner and outer devices may be forwarded simultaneously or one after another via a respective (other) one of the atrial and ventricular chambers or via the respective same of the atrial and ventricular chambers.

The (new, replacing or non-native) valve attached to the circumferential support member can be made of biological tissue, for example, of pericardium, or it can be an artificial valve made of a synthetic material, such as of a plastic film material, for example a PE film material. The non-native valve may be provided as a flap valve arranged in an interior of the circumferential support structure of the inner device, and having one or a plurality of (co-acting) flaps.

When the circumferential support structure is in its finally implanted position, for example between the native valve leaflets and/or the native valve annulus, and will be expanded, the circumferential support structure radially and inwardly contacts against the inner periphery of the circumferential or peripheral connection channel wall structure, for example against the inner periphery of the connection channel wall formed by the native valve annulus and the native valve leaflets. In this respect, the circumferential support structure may be expandable to merely (in general) abut against the said inner periphery without causing inner pressure as such. In this case, the active clamping action is caused by an outer device which is a contractible device and which then can radially and inwardly contract the circumferential connection channel wall structure against the inner device. It is also possible that the outer device is generally not radially contractible, and the clamping force can be actively provided by the inner device, that is, by the expandable circumferential support structure radially expanded to press the (native) circumferential connection channel wall structure against the inner periphery of the outer device. It is also possible that both the inner device, for example its circumferential support structure, and the outer device are expandable and contractible, respectively, such that both provide for such radial forces so as to be able to actively press against the circumferential connection channel wall structure from the inner side and the outer side thereof.

The outer device may be one or more collapsible and correspondingly (re-)expandable or formable, for example circumferentially closed, rings or tubular members, for example in form of one or a plurality of snares, which extend around, for example completely around, the (circumference of the) inner device and can be arranged around, for example completely around, the native connection channel and, hence, the outer circumference of the corresponding circumferential connection channel wall structure. Accordingly, by using a ring, the clamping mechanism can continuously (that is, without interruptions) circumferentially clamp the connection channel wall structure. The outer device may be a closed ring or circumferentially closed tubular member or may be formed as a clamp, for example, as a circumferentially open ring or tubular member (that is, a ring that is open at its circumference such as, for example, a C-shaped ring or a U-shaped ring, or a helix, or a tubular member that is open at its circumference along its longitudinal direction, such as a tubular member having a C-shaped or U-shaped cross-section). Further in this respect, circumferentially open ring or tubular member means that the corresponding (circumferential) free ends of the open ring or tubular member are not connected to each other (are not interconnected) and, hence, are provided connection-free or locking-free. The outer device needs to be deformable, for example collapsible, to also allow delivery thereof by means of a catheter in a percutaneous manner. In the event of an outer device shaped as a tubular member, whether eventually closed or open, it can be made of a material inflatable through a lumen in the delivery catheter, especially in order to take a certain shape or size. It can further be inflated with a material that can be injected in a liquid state and that can be turned into a solid, non-deformable component. This can be achieved for instance with a polymer hardening over time or by further addition of energy (for example, heating, ultrasound, UV light or other electromagnetic radiation) or a hardening, drying or reticulating agent. Alternatively, or in addition, the outer device can be made tubular in order to be delivered while positioned over the delivery catheter rather than inside the delivery catheter's lumen. This could then enable delivery of a fastening mechanism (clip, screw, suture. ) from the inside of the delivery catheter to the inner side of the tubular outer device. This fastening mechanism could perforate the tubular outer device so as to enable attachment of one end of the outer device to the other end or of an area of the outer device to the anatomy (connection channel wall structure) or to the inner device.

A wire, which may also be a ribbon or a rope, may be used as material for the outer device, the wire forming the above-mentioned ring around the circumferential connection channel wall structure. The wire or wire material may be flexible and non-elastic, but may also be flexible and elastic so as to be able to always provide an elastic clamping force against the inner device.

In general, the outer device may be non-elastically contractible up to any appropriate inner diameter, or the outer device may be elastically contractible up to an inner diameter which, for example is equal or smaller than the outer diameter of the inner device, so as to ensure an elastic clamping force against the circumferential connection channel wall structure when being implanted.

The wire or wire material as such may be linearly forwarded to the atrio-ventricular valve through a catheter and may be wound circumferentially around the outer periphery of the circumferential connectional channel wall structure to form the outer device in the shape of one or more rings such as snare rings. Such rings may be arranged in a respective distance to each other along an axial extension of the inner device along the direction of the connection channel/through opening formed by native atrio-ventricular valve. The wire ring can be easily further contracted to correspondingly contract the connection channel and circumferential connection channel wall structure radially inwardly against the inner device and the circumferential support structure thereof. Thereby, a tight and thereby sealed and reliable circumferential connection between the circumferential support structure with the (new/replacing) valve attached thereto and the inner periphery/circumference of the circumferential connection channel wall structure can be achieved. In this respect, as mentioned above, the inner device with its circumferential support structure may be arranged within the native valve annulus or at an interior position close thereto and in-between the native valve leaflets, and the outer device may be arranged around the exterior of the native valve leaflets close to the native valve annulus to thereby circumferentially and tightly clamp the native valve leaflets, which form part of the connection channel and, thus, of the connection channel wall structure thereof, between the inner and outer devices, thereby providing for safe and reliable seal as well as fixation functions. As mentioned above, the inner device and/or the outer device may also and/or additionally be provided on the inner and outer, respectively, peripheries of further elements of the circumferential connection channel wall structure, such as within and around, respectively, the periphery of the chordae tendinae, the periphery of the papillary muscle(s), and the periphery of the atrial wall.

The outer device, for example the ring, such as the wire ring or ribbon ring, may be of a shape-memory material (e.g., Nitinol) so as to be able to create a contracting force around the native leaflet and inner device, without requirement of any externally applied cinching force. The shape memory material can be characterized by its transition temperature (Af temperature) separating the cold, deformable state (martensitic phase) from the warm state (austenitic phase) where the component spring back to its original shape. The Af temperature of the shape memory material could be set in such a range (e.g., between <NUM> and <NUM>) that the outer device is inserted into position in the anatomy in its cold, deformable state (martensitic phase) so as to enable delivery through the fortuosities of the vasculature and adequate positioning without resistance. It could then be heated beyond the Af temperature, for instance by an electric current, so as to conform to its original shape in its warm state (austenitic phase). Its original shape could be set in such a way that upon recovering this shape after cold deformation and upon heating, a freeze mechanism like a ratchet or anchoring becomes active for instance enabling the two ends of the outer device to become connected. This features would enable the outer device to maintain its shape and position despite partially cooling down again after the heating action is stopped.

The inner device and the outer device may be separated from each other and may be not in a physical contact with each other. However, the inner and outer devices may also include projections projecting toward each other and penetrating the tissue of the circumferential connection channel wall structure clamped in-between, wherein the penetrating projections of the inner and outer devices may come in contact with the respective other one of the inner and outer devices.

The inner device, for example its circumferential support structure, extends along an axis along the through opening therethrough (following the direction of the native connection channel or through opening through the native atrio-ventricular valve), and the outer device, for example provided as a ring, may be arranged at a position along said axis, that is between the axial ends of the inner device, for example between the ends of the circumferential support structure, to thereby be arranged in a distance (axial distance) from these ends. The inner device, for example its circumferential support structure, may have an elongate shape so that said axis may be the longitudinal axis and the ends may be the longitudinal ends.

The inner and outer devices may also include means for engaging the circumferential connection channel wall structure from the respective inner and outer peripheries thereof. In this respect, the inner device, for example its circumferential support structure, may comprise barbs, hooks, anchor part(s), or other projections for penetrating into the circumferential connection channel wall structure from the interior thereof. Correspondingly, the outer device may include such projections for correspondingly penetrate into the circumferential connection channel wall structure.

On the other hand, the inner device may also be free of projections at or on its outer surface (outer circumferential surface).

Further, the outer device formed by a wire or ribbon may also be at least partially interwoven into the chordae tendinae structure to thereby internally extend therearound, but still in a radial distance to the inner device and its circumferential support structure arranged on the inner periphery of the circumferential connection channel wall structure.

The inner device, for example its circumferential support structure, may be provided with an outer circumferential or peripheral indentation, for example a groove, for example with a V-shaped or U-shaped cross-section, and the outer device may comprise a closed or open ring engaging the indentation, for example the groove, with the connection wall channel structure clamped therebetween. The width of the groove, for example of the U-shaped groove, may be substantially adapted/substantially correspond to the cross-sectional dimension of the ring (ring wall) or may be slightly greater such as to still allow tissue of the corresponding wall structure portion of the circumferential connection channel wall structure to be pressed into the groove following the groove's cross-section, for example the U-shaped cross-section thereon, and laterally pressed against the lateral walls of the groove, and for example additionally pressed against the bottom/base of the groove, for example pressed against the base and/or laterally pressed against the legs of the U-shaped cross-section. The circumferential groove may be a continuously circumferentially extending groove or may extend circumferentially in an interrupted manner. The groove may be formed by (between) adjacent rips which radially protrude from the outer surface of the inner device (such as from its circumferential support structure) and which circumferentially, for example in a continuous or interrupted manner, extend around the inner device (such as around its circumferential support structure). The groove may also be formed by adjacent rows of separated projections (such as bosses) which radially protrude outwardly from the outer surface of the inner device (such as from the outer surface of the circumferential support structure). The groove may also be formed as circumferentially extending (for example in a continuous manner) recess provided in the otherwise smooth or projection-free outer surface of the inner device (such as of the circumferential support structure).

The inner device, for example its circumferential support structure, may be provided with an outer circumferential projection (rib-like projection) as the outer circumferential indentation, and the outer device may comprise one or two rings arranged adjacent to and (in case of two rings) on opposite (axial) sides of the outer circumferential projection.

According to the present invention the circumferential support structure of the inner device is provided, on its outer periphery, with a compressible material or a compressible structure (the compressible material/structure may be different from the material of the circumferential support structure), such as a foam material, for example as a coating or coating structure or surface structure/material, wherein the outer device, for example the ring shaped outer device, then locally compresses said compressible material, for example along the circumference of the ring of the outer device, to thereby form a corresponding (circumferential) groove in the compressible material.

The inner device may further have a funnel shape to approach the funnel shape of the connection channel/through opening through the native valve annulus and native valve leaflets of the atrio-ventricular valve in the area of the native valve annulus.

The implantation procedure may be carried out under various visualization means, such as angiography, echography (Trans Esophageal Echo, Trans Thoracic Echo, Intra Cardiac Echo), MRI.

The catheter(s) for forwarding the inner and outer devices may, for example, be inserted by any of the following paths for treatment of the mitral valve: <NUM>) over an arterial retrograde approach entering the heart cavity over the aorta, <NUM>) through a venous access and through a puncture through the inter atrial septum (trans-septal approach), <NUM>) over a puncture through the apex of the heart (trans-apical approach) or <NUM>) over a puncture through the atrial wall from outside the heart.

The catheter(s) for forwarding the inner and outer devices may, for example, be inserted by any of the following paths for treatment of the tricuspid valve: <NUM>) over an arterial retrograde approach entering the heart cavity over the pulmonary artery following a surgical access of the later, <NUM>) through a venous access, <NUM>) over a puncture through the apex of the heart (trans-apical approach) or <NUM>) over a puncture through the atrial wall from outside the heart.

A possible access for delivering the outer device, for example the wire, ring or snare, is an arterial access (e.g., the femoral artery through a puncture in the groin). A guide-wire may be advanced over the aorta through the aortic valve inside the left ventricle. Over the guide-wire, a guiding catheter can be advanced. The catheter may be pre-shaped on its distal end with an angle of approximately <NUM>° in such a way that it enables positioning of the guide-wire in the sub-annular groove (the space bellow the mitral annulus and between the ventricular wall and the posterior leaflet). Over the guide-wire and inside the guiding catheter, a second pre-shaped catheter can be advanced that will, upon exiting the guiding catheter, position itself around the posterior leaflet inside the sub-annular groove. Advancing the guide-wire inside that pre-shaped catheter allows it to travel around the posterior and the anterior mitral leaflet. A second lumen inside the guiding catheter (for example in form of a second catheter, or a second catheter) allows positioning of a snare to catch the guide-wire after its loop around the native valve leaflets, whereby the native valve leaflets are caught in a lasso manner.

Optionally a catheter can be threaded over the guide-wire to position an anchor (member) inside the ventricular wall or the annulus close to selected areas like the middle of the posterior leaflet. This anchor (member) allows maintenance of the relative height of the guide-wire so as to avoid grabbing the native leaflet too low. It also allows the apparatus to favor the final position of the stent-valve, that is, the inner device with its circumferential support structure and valve, within the mitral annulus plane close to the posterior wall so as for instance to grab a greater length of the posterior leaflet.

In embodiments, the guide-wire can be exchanged for a different kind of lasso with additional features (greater contact surface, barbs on its surface, shape memory. In addition, if the custom made lasso does not already provide for it, a stopping device can be advanced so as to close the loop and freeze it at a given circumference optimal for stent-valve anchoring.

The outer device, for example formed as a ring, such as a wire ring or snare ring, may be positioned around the native leaflets in such a way that it wraps those leaflets around the deployed inner device. The ring can be positioned at different heights, wherein a (height) position providing an improved sealing function may be seen to be a position as close as possible to the native valve annulus. In this regard, the native leaflets are used to anchor the atrio-ventricular (mitral) valve prosthesis as well as to achieve peri-prosthetic sealing. Preferable, the ring is inserted around the native valve annulus so as to be positon above the chordae tendinae to provide an improved sealing function.

The outer device, for example, formed as ring, such as a wire ring or snare ring, may be fixed into place, and thus remain attached inside the hear upon completion of the implantation of the atrio-ventricular (mitral) valve prosthesis. Alternatively, the wire ring or snare ring may be used to position the native leaflets in a selected area to activate an anchoring mechanism, and may be subsequently removed. That is, in some embodiments, the wire ring or snare ring may be used only during the implantation procedure.

According to an aspect of the invention, the outer device, for example in addition to the ring thereof, may further comprise one or more staples arranged around the periphery/circumference of the inner device and each having a base member arranged in a radial distance to and outwardly of the inner device to clamp the circumferential connection channel wall structure between the base member and the inner device and each having penetration legs for penetrating the circumferential connection channel wall structure and engaging the inner device, for example the circumferential support member thereof, for being fixed thereon and for providing the clamping force between the base member and the inner device.

According to an aspect of the invention, for example in addition to the ring and/or in addition to the staples of the outer device, the outer device may comprise one or more clips arranged around the outer circumference or outer periphery of the inner device and having a U-shape with a base portion and two legs extending from the base portion, one of the legs extending in a radial distance to and outwardly of the inner device, the other one of the legs engaging the inner device, for example by engaging the circumferential support member at an inner peripheral/circumferential side thereof, and the base portion may be arranged at a free front end of the native valve leaflets, whereby the clip(s) (axially) extend around the free front end of the native valve leaflets, and the legs clamp the circumferential connection channel wall structure, formed by the leaflets in this area, and the circumferential support structure together, whereby the circumferential connection channel wall structure (here, the native valve leaflets) is positioned between the one clip leg and the circumferential support member of the inner device.

The above-mentioned clips or staples can be inserted through the leaflets to the inner device (clipping from the 'outside'), or through the inner device to the leaflets (clipping from the 'inside'). In the latter case, the base member of the respective staple is arranged on an inner peripheral side of the inner device, for example of the circumferential support member, and the penetration legs of the staple penetrate the circumferential connection channel wall structure from an inner side to an outer side, with the free end of the penetration legs extending in a radial distance outwards of the inner device therealong or therearound, whereby the circumferential connection channel wall structure is clamped between the free ends of the penetration legs and the inner device.

In case of using the above-mentioned clips and/or staples arranged in angular intervals around the circumference of the inner device, the clamping mechanism can correspondingly clamp in a non-continuous (interrupted) circumferential manner.

As an alternative to the outer device, or in addition to the outer device, the inner device may comprise anchors or hooks fixed to the inner device and extending therefrom to be positioned inside the heart muscle (papillary muscle or ventricular wall) to enable the inner device to further resist the back pressure. In this respect, for example, the outer device may comprise elongate anchor elements which extend from the inner device by a (axial) distance so as to be able to penetrate with free ends thereof into native papillary muscle(s) when the inner device is in a finally implanted position within the connection channel.

Further, the inner device itself may contain components to facilitate its inherent anchoring such as hooks, barbs, an adhesive surface (biological glue), arms or cuffs to wrap around the native leaflets or the chordae tendinae or combinations thereof. According to an aspect of the invention, for example in addition to the ring and/or in addition to the staples and/or in addition to the clips, the outer device may comprise one or more arms extending at the outer periphery of the inner device in a radial distance thereto, to thereby be able to clamp the circumferential connection channel wall structure radially between the arm(s) and the inner device, the arms, starting from a free end thereof, (axially) extend in parallel to the inner device (for example, the circumferential support structure thereof) to thereby form a corresponding radial gap therebetween for receiving the circumferential connection channel wall structure therein for being clamped, and extend towards the inner device (for example, the circumferential support structure thereof) to be connected thereto, for example at an axial end of the inner device (e.g., of the circumferential support structure thereof). Thereby, the arms distributed around the outer periphery of the inner device form a collar therearound for radially wrapping the free ends of the native valve leaflets and for radially clamping the (free ends of the) native valve leaflets in the radial gap between the radial inner side of the collar and the inner device (for example the circumferential support member).

<FIG> shows a transcatheter atrio-ventricular valve prosthesis <NUM> according to an embodiment implanted between left atrial and ventricular chambers <NUM>, <NUM> of a human heart <NUM> to replace the (function of the) native mitral valve <NUM> as the native atrio-ventricular valve between said left atrial and ventricular chambers <NUM>, <NUM>. The native mitral valve <NUM> comprises a native valve structure including native valve leaflets <NUM>, a native valve annulus <NUM>, native chordae tendinae <NUM>, and native papillary muscle(s) <NUM>. The native valve annulus <NUM>, the native valve leaflets <NUM>, chordae tendinae <NUM> and the papillary muscle(s) <NUM> form a connection channel <NUM> between the atrial and ventricular chambers <NUM>, <NUM>, and said connection channel <NUM> has a circumferential connection channel wall structure <NUM>'.

The valve prosthesis <NUM> of <FIG> comprises an inner device <NUM> with a circumferential support structure <NUM> in form of an elongate tubular mesh-like body, within which a valve <NUM> in form of a three-flap structure is arranged and attached/fixed, for example non-detachably attached, to the circumferential support structure <NUM>. The (new) valve <NUM> and, hence, its flap structure is provided such as to close a replacement connection opening/replacement connection channel provided through or interiorly defined by the circumferential support structure <NUM>, here along the longitudinal axis of the circumferential support structure <NUM>, when the left ventricular chamber <NUM> is contracted, and to open said replacement connection channel when the left ventricular chamber <NUM> is expanded. In this case, the inner device <NUM> with its circumferential support structure <NUM> and its valve <NUM> therewithin is arranged in-between the native leaflets <NUM> as well as within the native valve annulus <NUM> and, thus, within the (native) connection channel <NUM> in physical and circumferential contact with the inner side of the circumferential connection channel wall structure <NUM>' thereof.

The circumferential support structure <NUM> is radially compressible to thereby being insertable into the mitral valve <NUM> by means of a catheter <NUM> via a percutaneous approach. When being in place in the interior of the connection channel <NUM>, the circumferential support structure <NUM> is brought from its collapsed condition into a deployed condition circumferentially abutting, for example pressing, against the inner periphery of the circumferential connection channel wall structure <NUM>' of the connection channel <NUM> of the native atrial valve <NUM>, here against the inner periphery of both the native valve leaflets <NUM> and the native valve annulus <NUM>.

The valve prosthesis <NUM> further comprises an outer device <NUM> in form of or comprising a wire ring <NUM> or snare ring <NUM> disposed on and extending completely around an exterior or outer side of the connection channel <NUM> and of the circumferential connection channel wall structure <NUM>' thereof, here, around the native valve leaflets <NUM> at a position close to the valve annulus <NUM> and between longitudinal ends of the circumferential support structure <NUM> of the inner device <NUM>. In this embodiment, the outer device <NUM> is separate from the inner device <NUM> and is not in physical contact therewith. The ring-shaped outer device <NUM> thereby circumferentially extends around the inner device <NUM> in a radial distance thereto, wherein the circumferential connection channel wall structure <NUM>', here the circumferential connection channel wall formed by the native valve annulus <NUM> and the native valve leaflets <NUM>, is clamped between the inner and outer devices <NUM>, <NUM> which thereby form a clamping mechanism for continuously circumferentially clamping the connection channel wall structure <NUM>' therebetween.

The wire ring <NUM> of the outer device <NUM> may be provided elastically or non-elastically contractible so as to be able to add additional active clamping force from radially outside of the valve structure <NUM>, <NUM>, <NUM>, <NUM> thereagainst. The wire material of the wire of the outer device <NUM> may be linearly forwarded to the exterior of the circumferential connection channel wall structure <NUM>' via a catheter <NUM> forwarded via a percutaneous approach.

As can be further seen in <FIG>, the elongated tubular shaped circumferential support structure <NUM> of the inner device <NUM> extends along a (longitudinal) axis which in turn extends along the longitudinal axis of the connection channel <NUM> (axis extending cross to the through opening between the atrial chamber <NUM> and the ventricular chamber <NUM>), whereby the circumferential support structure <NUM> correspondingly has (two) axial ends <NUM>', <NUM>". At one of the axial ends <NUM>', <NUM>", which is proximal to the native valve annulus <NUM>, the circumferential support structure is formed in a funnel shape (defining a funnel portion <NUM>) to approach the native funnel shape of the connection channel <NUM> in the area of the native valve annulus <NUM>. The ring-shaped outer device <NUM> is arranged in a (an axial) distance from the axial ends <NUM>', <NUM>" therebetween and, thereby, in an axial distance from the funnel portion <NUM>.

By means of <FIG> an approach for implanting the prosthesis <NUM> according to <FIG> will now be explained.

As can be seen from <FIG>, firstly the catheter <NUM> is forwarded to the left ventricular chamber <NUM> via the aorta and the aorta valve <NUM>, and is then guided around the circumferential connection channel wall structure <NUM>' of the connection channel <NUM>, at the level (height) of the native valve leaflets <NUM> close to the native annulus <NUM>, of the mitral valve <NUM> to be functionally replaced by the prosthesis <NUM>. That is, the catheter <NUM> is guided around the circumferential connection channel wall structure <NUM>' of the connection channel <NUM> and not around the chordae tendinae, which could otherwise undesirably result in the ring-shaped outer device <NUM> being caught on or placed between chordae tendiane. A flexible and non-elastic wire <NUM>' which will form the later ring <NUM> of the outer device <NUM> is guided through the catheter <NUM> and, thereby, is guided around the outer circumference of the circumferential connection channel wall structure <NUM>' at the corresponding level of the native valve leaflets <NUM>. The catheter <NUM> is then slightly retracted and the wire <NUM>' is then provided as contractible loop <NUM> (lasso type) having a diameter greater than the (cross-sectional) outer diameter of the circumferentially extending connection channel wall structure <NUM>' and greater than the diameter of the final ring <NUM> of the outer device <NUM>. The loop <NUM> thereby extends around the connection channel <NUM> at a radial distance thereto, that is, at a radial distance to the connection channel wall structure <NUM>', and allows the inner device <NUM> to be appropriately inserted into the inner side/interior of the connection channel <NUM>.

In order to catch the free end <NUM>" of the wire <NUM>' and to thereby form the loop <NUM>, a catching wire or additional lasso wire, having a contractible catching snare <NUM> at its distal end, is forwarded through the catheter <NUM>. By means of said snare <NUM> of the catching wire the free end <NUM>" of the wire <NUM>' is caught and drawn into the catheter <NUM> to thereby form the loop <NUM> formed by the wire <NUM>', which loop then can be further contracted to closely circumferentially engage the connection channel wall structure <NUM>'. Instead of the shown snare <NUM>, a catching basket (not shown) may be used for catching the free end <NUM>" of the wire <NUM>', which is provided on the snare or lasso wire. Such a catching basket may, for example, be formed as a tubular member provided with longitudinal slots, wherein the tubular member can be axially contracted to laterally widen the longitudinal slots, in order to receive the free end <NUM>" within one or more of the longitudinal slots, and can be axially re-extended (after axial contraction) to thereby laterally narrow/close the previously widened slots to thereby catch/fix the free end <NUM>" of the wire <NUM>' therein. It is to be noted that other catching mechanisms/catching devices may be used, instead of the catching snare or catching basket, to catch or grip the free end of the wire <NUM>", such as any gripping device, such as a gripper device or forceps.

As can be seen from <FIG>, the catheter <NUM> is then forwarded to the left atrial chamber <NUM> via a puncture <NUM> through the inter atrial septum, and the inner device <NUM> with its circumferential support structure <NUM> and the (new or replacing) valve <NUM> therein is forwarded in its collapsed condition through the catheter <NUM> to be disposed in-between the native leaflets <NUM> and the native annulus <NUM> forming part of the connection channel <NUM>. Then the circumferential support structure <NUM> is deployed by either radial self-expansion or radial expansion by means of, for example, an inflatable balloon inserted into the interior of the circumferential support structure <NUM>, whereby the circumferential support structure <NUM> radially and outwardly presses against the inner periphery of the circumferential connection channel wall structure <NUM>' in the area of and at the level of the native valve annulus <NUM> and the native valve leaflets <NUM>. As can be seen from <FIG>, the loop <NUM> is then contracted to provide a radial counter-force against the radial force provided by the inner circumferential support structure <NUM>, acting radially and inwardly against the circumferential outer periphery of the circumferential connection channel wall structure <NUM>' at a level of the native valve leaflets <NUM> adjacent to the native valve annulus <NUM>. Thereby, the connection channel wall structure <NUM>' of the connection channel <NUM> and, for example in this case, the native valve leaflets <NUM> and the native valve annulus <NUM>, is prevented from being inappropriately radially expanded and is circumferentially clamped in-between the circumferentially extending loop <NUM> and the circumferential support structure <NUM> of the inner device <NUM>. Finally the diameter of the loop <NUM> is fixed to thereby finalize the ring <NUM> forming the outer device <NUM> in this case, and thereby finalizing the implantation of the atrio-ventricular (here mitral) valve prosthesis <NUM> as shown in <FIG>.

In sum, with respect to <FIG>, the loop <NUM> is first positioned around the native valve annulus <NUM>. Afterward, the inner device <NUM> with its circumferential support structure <NUM> and the valve <NUM> therein is forwarded in its collapsed condition through the catheter <NUM> to be disposed in-between the native leaflets <NUM> and the native annulus <NUM> forming part of the connection channel <NUM>. Next, the loop <NUM> is tightened to pull the native leaflets <NUM> toward the inner device <NUM>, which is expanded from the collapsed condition. The loop <NUM> can then either be frozen in position and then removed once the inner device <NUM> is secure, or the loop <NUM> may be non-frictionally employed to the position the inner device and allow another form of anchoring to be activated, and then the loop <NUM> is subsequently removed.

<FIG> shows an atrio-ventricular valve prosthesis <NUM> according to another embodiment.

According to this embodiment, the circumferential support structure <NUM> of the inner device <NUM> is provided with an indentation in form of an outer circumferential groove <NUM>, and the ring-shaped or snare-shaped outer device <NUM> is arranged to be (axially) aligned to the outer circumferential groove <NUM>. That is, the ring-shaped outer device <NUM> is arranged at the level of the outer circumferential groove <NUM> to thereby force the corresponding area of the native valve leaflets <NUM> and, hence, the corresponding area of the connection channel wall <NUM>' of the native mitral valve <NUM> radially into the outer circumferential groove <NUM> as a result from clamping the said area of the circumferential connection channel wall structure <NUM>' between the outer and inner devices <NUM>, <NUM>. The circumferential groove <NUM> may allow for a use of the ring-shaped outer device <NUM> that does not involve frictionally securing the prosthesis in place. That is, the ring-shaped outer device may, upon tightening be loosely position within the circumferential groove <NUM> to ensure proper position of the atrio-ventricular valve prosthesis <NUM> (see <FIG>) until the inner device <NUM> is secured to the circumferential connection channel wall structure <NUM>' with, for example sutures, staples, barbs, adhesives or another anchor mechanism.

As can be further seen in <FIG>, the circumferential support structure <NUM> of the inner device <NUM> is of an elongated tubular shape and extends along an axis which in turn extends along the longitudinal axis of the connection channel <NUM> (axis extending cross to the through opening between the atrial chamber <NUM> and the ventricular chamber <NUM>), whereby the circumferential support structure <NUM> correspondingly has (two) axial ends <NUM>', <NUM>". At one of the axial ends <NUM>', <NUM>", which is proximal to the native valve annulus <NUM>, the circumferential support structure is formed in a funnel shape (defining a funnel portion <NUM>) to approach the native funnel shape of the connection channel <NUM> in the area of the native valve annulus <NUM>. The funnel shape of the funnel portion <NUM> can minimize or prevent one way migration of the circumferential support structure <NUM> of the inner device <NUM>. The circumferential support structure <NUM> of the inner device <NUM> may also have hooks, barbs or some other anchor mechanism that prevents migration of the circumferential support structure <NUM> of the inner device <NUM>, at least in an opposite direction from that prevented by the funnel portion <NUM>. The ring-shaped outer device <NUM> and correspondingly the groove <NUM> aligned therewith are arranged in a distance (axial distance) from the axial ends <NUM>', <NUM>" between the axial ends <NUM>', <NUM>" and, thereby in an axial distance from the funnel portion <NUM>.

<FIG> shows an implantation approach, according to which both catheters <NUM>, <NUM> for forwarding the inner device <NUM> and the outer device <NUM>, respectively, are forwarded to the native mitral valve <NUM> via the atrium <NUM> and a puncture <NUM> through the atrial wall from outside the heart. Instead of the puncture <NUM>, the atrium <NUM> may also be surgically accessed, wherein the access may be carried out on a beating heart or on an arrested heart.

<FIG> shows an implantation approach, according to which the catheter <NUM> for forwarding the inner device <NUM> to the native mitral valve <NUM> is forwarded via the left atrial chamber <NUM>, and the catheter <NUM> for forwarding the outer device <NUM> to the native mitral valve <NUM> is forwarded via a puncture <NUM> through the apex of the heart (trans-apical approach).

<FIG> shows an embodiment according to which the outer device <NUM>, for example in addition to the ring-shaped device <NUM> of <FIG>, additionally or only comprises a plurality of staples arranged around the periphery of the inner device <NUM>. The inner device <NUM> is provided as tubular stent as described in connection with the embodiment of <FIG> so that it is referred to the corresponding description above. The respective staple has a base member <NUM> extending in a radial distance to the circumferential support structure <NUM> of the inner device <NUM> at a radial outer side thereof to thereby clamp the circumferential connection channel wall structure <NUM>' (here, the native valve leaftlets <NUM>) radially between the base member <NUM> of the staple and the inner device <NUM> with its circumferential support member <NUM> and valve. The radial clamping force is in this case achieved by penetration legs <NUM> radially penetrating the circumferential connection channel wall structure <NUM>' (here, the native valve leaftlets <NUM>) from the outside towards the inside and engaging the mesh-structure of the circumferential support structure <NUM> to thereby radially and peripherally draw said circumferential support structure <NUM> towards the respective staple base member <NUM> with the circumferential connection channel wall structure <NUM>' (here, the native valve leaflets <NUM>) clamped therebetween.

<FIG> shows an embodiment according to which the outer device <NUM>, for example in addition to the ring-shaped device <NUM> of <FIG> and/or in addition to the staples of <FIG>, additionally or only comprises a plurality of clips or clamps arranged around the outer periphery of the inner device <NUM> at the free ends of the native valve leaflets <NUM> and at an axial end of the inner device <NUM>. The inner device <NUM> is provided as a tubular stent as described in connection with the embodiment of <FIG> so that it is referred to the corresponding description above. The respective clip is generally of U-shape with a U-base portion <NUM> and two U-leg portions <NUM>, <NUM>. The clips are arranged such as to respectively encompass the free end of the native valve leaflets <NUM> and the axial front end of the tubular inner device <NUM>, wherein an outer leg portion <NUM> of the leg portions <NUM>, <NUM> extends in a radial distance to the inner device <NUM> along the axial direction thereof and is in a clamping contact with the radial exterior side of the circumferential connection channel wall structure <NUM>' (here, the native valve leaflets <NUM>), and an inner leg portion <NUM> extends along the axial direction of the inner device <NUM> (along the circumferential support structure <NUM>) and is in a clamping contact therewith, whereby the inner device <NUM> (including the circumferential support structure <NUM> thereof) and the connection channel wall structure <NUM>' (here, the native valve leaflets <NUM>) are radially clamped between the leg portions <NUM>, <NUM> of the respective clip.

<FIG> shows an embodiment according to which the outer device <NUM>, for example in addition to the ring-shaped device <NUM> of <FIG> and/or in addition to the staples and/or clips of <FIG> and <FIG>, additionally or only comprises a plurality of arms extending around the outer circumference/periphery of the inner device <NUM> in a radial distance thereto, to clamp the circumferential connection channel wall structure <NUM>' radially between the arm(s) and the inner device <NUM>, the arms, starting from a free end <NUM> thereof, extend in parallel to the inner device <NUM> (for example, the circumferential support structure thereof <NUM>) to thereby respectively form a corresponding radial gap <NUM> therebetween for receiving the circumferential connection channel wall structure <NUM>' (here the free ends of the valve leaflets <NUM>) therein for being clamped, and extend towards the inner device <NUM> (for example, the circumferential support structure <NUM> thereof) and are fixedly connected to the inner device <NUM> at an axial end thereof. Thereby, the arms <NUM> distributed around the outer periphery of the inner device <NUM> form an angularly interrupted collar <NUM> therearound for radially wrapping the connection channel wall structure <NUM>' (here, the free ends of the native valve leaflets <NUM>) and for radially clamping the connection channel wall structure <NUM>' (here, the (free ends of the) native valve leaflets <NUM>) in the radial gap <NUM> between the radial inner side of the collar <NUM> and the inner device <NUM> (for example the circumferential support member <NUM>). The inner device <NUM> is provided as a tubular stent as described in connection with the embodiment of <FIG> so that it is referred to the corresponding description above.

<FIG> shows an embodiment according to which in addition to the outer device <NUM> or, for example, as an alternative thereto, the inner device <NUM>, which is provided as a tubular stent as described in connection with the embodiment of <FIG>, comprises elongate anchor elements <NUM>, for example in form of elongate wire anchors provided with hooks or barbs <NUM> at free ends <NUM> of the anchor elements <NUM>, which anchor elements <NUM> axially extend from the inner device <NUM> by a distance so as to be able to penetrate with their free ends <NUM> into the native papillary muscle(s) <NUM>, when the stent-type inner device <NUM> is in its finally implanted position within the native mitral valve <NUM>, for example between the native valve leaflets <NUM> thereof.

In all aspects the (new/replacing) valve attached to the circumferential support structure of the stent-type inner device may comprise a circumferential wall portion which is circumferentially and radially clamped as part of the inner device against the inner periphery of the circumferential connection channel wall structure of the native atrial-ventricular valve to thereby provide for further improved seal function between the circumferential connection channel wall structure and the inner device. The outer device may be arranged aligned to or at a level of said circumferential wall portion of the (new/replacing) valve to thereby provide the clamping force at the level of or at least close to said circumferential wall portion of the valve.

<FIG> shows an approach for implanting a transcatheter atrio-ventricular valve prosthesis <NUM> within the native tricuspid valve <NUM>' for replacing the function thereof. The prosthesis <NUM> according to this embodiment is identical to the prosthesis according to <FIG> so that regarding the structure of the prosthesis of <FIG> it is referred to the description of the embodiment of <FIG>. The native tricuspid valve <NUM>' defines a connection channel <NUM>, having a circumferential connection channel wall structure <NUM>', fluidly connecting the right atrial and ventricular chambers <NUM>', <NUM>'.

As can be seen from <FIG>, the inner device <NUM> is forwarded to the tricuspid valve <NUM>' via the superior vena cava <NUM>, connected to the right atrium <NUM>', by means of a catheter <NUM>, and the outer device <NUM> is forwarded to the exterior of the connection channel <NUM>, that is to the right ventricular chamber <NUM>' and, thus, to the exterior of the circumferential connection channel wall structure <NUM>', via the inferior vena cava <NUM> and a passage <NUM> between the leaflets <NUM>' of the tricuspid valve <NUM>'. Alternatively, the catheter <NUM> with the inner device <NUM> may be forwarded via the inferior vena cava <NUM>, and the catheter <NUM> with the outer device <NUM> may be forwarded via the superior vena cava <NUM>, or both catheters <NUM>, <NUM> may be forwarded via the same one of the superior vena cava <NUM> and inferior vena cava <NUM>. For introducing the catheters <NUM>, <NUM> into the veins <NUM>, <NUM> or, in case of a mitral valve prosthesis as described above, into the aorta, femoral, cervical and/or thoracic accesses may be used as appropriate and/or as presently known for other heart catheter applications, such as for the application of known heart catheter probes. Further, the catheter <NUM> with the inner device <NUM> may also be forwarded to the tricuspid valve <NUM>' via a puncture (not shown) through the right atrium <NUM>' or via a surgical access to the right atrium <NUM>', which may be carried out on the arrested or beating heart. The catheter <NUM> with the outer device <NUM> may also be forwarded via a puncture (not shown) through the right ventricular chamber <NUM>'.

<FIG> shows a perspective sectional view of a further embodiment and <FIG> shows a section along line B-B in <FIG>. The embodiment shown in <FIG> substantially corresponds to the embodiment of <FIG>, wherein, however, the ring <NUM> forming the outer device <NUM> is not a closed ring but an open ring having non-connected or non-interconnected free ends <NUM>', <NUM>" (cf. The ring-shaped outer device <NUM> is arranged at the (axial) level of the groove <NUM> provided in and circumferentially extending around the inner device <NUM> (that is, provided in and extending around the circumferential support structure <NUM> of the inner device <NUM>). That is, the ring <NUM> forming the outer device <NUM> is aligned with the circumferential groove <NUM>. The section, shown in <FIG>, extends centrally through and along the groove <NUM>. Regarding the further details of the embodiment of <FIG>, it is referred to the above explanation of the embodiment of <FIG>.

<FIG> schematically show an approach for implanting a ring-shaped outer device <NUM> (cf. <FIG>) J of a transcatheter atrio-ventricular valve prosthesis <NUM>, as for example described above, according to an embodiment of the invention.

As can be seen from <FIG> and <FIG>, a first delivery catheter <NUM> and a second delivery catheter <NUM>, which are separate from each other (separate catheters) and, hence, which do not create a single interior but separate interiors, are forwarded to the ventricular chamber <NUM> (here the left ventricular chamber) of the heart <NUM> for example via the aorta (here) or for example via the superior or inferior vena cava (in case of right ventricular chamber). The first and second delivery catheters may be forwarded via a (same) primary delivery catheter <NUM> providing the primary access to the ventricular chamber <NUM> via the aorta or the vena cava.

As can be seen from <FIG> and <FIG> a wire <NUM>" is guided around about a circumferential portion, for example about the half circumference, of the circumferential connection channel wall structure <NUM>' of the connection channel <NUM> via the first delivery catheter <NUM> in one circumferential direction of the circumferential connection channel wall structure <NUM>', and a catching snare wire <NUM> with a catching basket <NUM> at a front end thereof (alternatively, for example, a catching snare <NUM> as shown in <FIG> and <FIG> may be used instead of the catching basket <NUM>) is guided around about the remaining circumferential portion, for example about the other half circumference, of the circumferential connection channel wall structure <NUM>'of the connection channel <NUM> via the second delivery catheter <NUM> in the other circumferential direction of the circumferential connection channel wall structure <NUM>', wherein the free end <NUM>" will be guided through the three dimensional structure of the catching basket <NUM> (or through the two-dimensional opening of the catching snare <NUM>) so as to be able to be caught by the catching basket <NUM> (or the catching snare <NUM>).

The wire <NUM>" and/or the catching wire <NUM> may be guided around the circumferential connection channel wall structure <NUM>' by means of first and second auxiliary delivery catheters <NUM>, <NUM>, respectively, which auxiliary delivery catheters <NUM>, <NUM> may have been previously forwarded through the first and second delivery catheters <NUM>, <NUM> and may be of a shape-memory material provided to return the first and second auxiliary delivery catheters <NUM>, <NUM> to assume a bow shape to be correspondingly able to automatically surround the circumferential connection channel wall structure <NUM>' when being exposed from the first and second delivery catheters <NUM>, <NUM>. Accordingly, as can be seen from <FIG> and <FIG>, the first and second auxiliary catheters <NUM> and <NUM> may be forwarded around the circumferential connection channel wall structure <NUM>' before forwarding the wire <NUM>' and the catching wire <NUM> therethrough.

As can be seen from <FIG>, with the free end <NUM>" of the wire <NUM>' reliably caught in the catching basket <NUM> (or catching snare <NUM>), the catching wire <NUM> is retracted back through the second delivery catheter <NUM> thereby guiding the wire <NUM>' further around, for example completely around, the circumferential connection channel wall structure <NUM>' to thereby form the loop <NUM> (also cf. <FIG>) to be further contracted to finally form the ring shaped outer device <NUM> or the device comprising the ring <NUM>. The first and second auxiliary catheters <NUM>, <NUM> may be retracted through the first and second delivery catheters <NUM>, <NUM> (cf. <FIG> and <FIG>) and then the first and second delivery catheters <NUM>, <NUM> may be retracted (cf. <FIG>) through the primary delivery catheter <NUM> which itself may be retracted at latest. The inner device may be installed within the connection channel <NUM> in a manner as described above.

<FIG> and <FIG> schematically show a perspective sectional side view and a perspective sectional top view of a transcatheter atrio-ventricular valve prosthesis <NUM> for functional replacement of an atrio-ventricular valve <NUM> in a connection channel <NUM>, having a circumferential connection channel wall structure <NUM>', between the atrial chamber <NUM> and the ventricular chamber <NUM> of a heart <NUM>. The prosthesis comprises an inner device <NUM> (which may have a structure in a manner as the inner devices as explained above) to be disposed in the interior of the connection channel <NUM>, the inner device <NUM> having a circumferential support structure <NUM> (which may have a structure in a manner as the circumferential support structures as explained above) which is radially expandable, and having a valve (which may have a structure in a manner as the valves as explained above) attached to the circumferential support structure <NUM>. The circumferential support structure <NUM> of the inner device <NUM> is of tubular shape and extends along an axis and has two axial ends <NUM>', <NUM>", and an outer device <NUM> (which may generally have a structure in a manner as the outer devices as explained above) to be disposed on the exterior of the connection channel <NUM> (that is, of the circumferential connection channel wall structure <NUM>'). The outer device <NUM> at least partly extends around the inner device <NUM> in a radial distance to the inner device <NUM>, and whereby the inner and outer devices <NUM>, <NUM> form a clamping mechanism for clamping the circumferential connection channel wall structure <NUM>' therebetween, wherein the outer device <NUM> comprises a ring <NUM>, for extending circumferentially around the circumferential connection channel wall structure <NUM>', arranged between and in a distance to the axial ends <NUM>', <NUM>" of the inner device <NUM>. The outer device <NUM> further comprises an anchor member <NUM> having one or more anchor parts <NUM>, such as barbs or hooks, to penetrate into the circumferential connection channel wall structure <NUM>' at a position close to the ring <NUM>, the anchor member <NUM> comprising an eye <NUM>, through which the ring <NUM> extends to thereby be anchored on the circumferential connection channel wall structure <NUM>' at this position by the anchor member <NUM>. The eye <NUM> may have a three-dimensional catching basket structure as for example shown for the catching basket <NUM> in <FIG>.

<FIG> and <FIG> schematically show a sectional side view and a sectional top view, respectively, illustrating an approach for implanting the transcatheter atrio-ventricular valve prosthesis <NUM> according to the embodiment of <FIG> and <FIG>. As can be seen from <FIG>, regarding implantation of the outer device <NUM>, as a first step, the anchor member <NUM> may be delivered to the ventricular chamber <NUM> and penetrates with its anchor part or parts <NUM> into the circumferential connection channel wall structure <NUM>', for example at a position at or adjacent to the annulus native valve annulus <NUM>. With the anchor member <NUM> anchored in this position, the wire <NUM>' may be guided around the circumferential connection channel wall structure <NUM>' in a manner as described above to form the ring <NUM> of the outer device <NUM>, wherein the wire <NUM>' is guided through the eye <NUM> of the anchor member <NUM>, whereby the wire <NUM>' and the finalized ring <NUM> and thereby the outer device <NUM> are reliably positioned and fixed/anchored to the circumferential connection channel wall structure <NUM>'. The inner device (not shown in <FIG> and <FIG>) may be structured in any shape as described above and may be implanted according to any approach as explained above. On the basis of the structure of this embodiment, as an alternative aspect to clamping the circumferential connection channel wall structure <NUM>' between the inner device <NUM> and the outer device <NUM>, the inner device <NUM> may be fixed to the inner side of the circumferential connection channel wall structure <NUM>' only by means of one or more anchor elements attached on the circumferential support structure and fixed to the circumferential connection channel wall structure <NUM>' for example via penetrating the circumferential connection channel wall structure <NUM>' and/or clamping, for example in manner as achieved by the staples <NUM>, <NUM> as described above (cf. for example <FIG>), the clips <NUM>, <NUM>, <NUM> as described above (cf. for example <FIG>), the collar <NUM> as described above (cf. for example <FIG>), the anchor elements <NUM> as described above (cf. for example <FIG>) and/or other suitable anchors and for example in combination with the funnel portion <NUM> as described above (cf. for example <FIG>). The outer device <NUM>, for example the ring <NUM>, may then not provide for a sufficient clamping action to secure inner device <NUM> within the connection channel <NUM>, but may only provide for such a clamping force (in connection with the counter-force provided from the inner device <NUM>) that a sealing effect/function is achieved between the circumferential connection channel wall structure <NUM>' and the inner device <NUM> (the circumferential support structure <NUM> thereof).

<FIG> shows a section side view in which the outer device <NUM> is employed to position the outer device <NUM> within the circumferential groove <NUM> to ensure proper positioning of the atrio-ventricular valve prosthesis <NUM> without frictionally securing the atrio ventricular valve prosthesis <NUM> in place.

Various figures herein illustrate that the ring <NUM> of the outer device <NUM> remains positioned around the inner device <NUM> upon completion of the implantation of the atrio-ventricular (here mitral) valve prosthesis <NUM>. However, the ring <NUM> of the outer device <NUM> can in embodiments be removed upon completion of the implantation. In such a case, the ring of the outer device <NUM> may be used only during the implantation procedure to position the native valve leaflets <NUM> in a selected area to activate an anchoring mechanism, for example, as described hereon, and may be subsequently removed. As illustrated in <FIG>, the outer device <NUM> may be removed, for example, by opening the catching basket <NUM> in such a manner that the outer device <NUM> is released and can be removed through the second delivery catheter <NUM>. Alternatively, the outer device <NUM> can be cut by a separate cutting mechanism, e.g., a catheter advanced over the outer device in place of the second delivery catheter <NUM>. The outer device could also be cut by an electric current that leads to the heating and rupture of a selected weak point of the outer device. It could also be made of a resorbable material and be degraded over a certain period of time.

Although the invention has been described on the basis of embodiments, the invention is not intended to be restricted to these embodiments, but is intended to cover all modifications, and variations within the scope of the invention as defined in the appended claims.

Claim 1:
A transcatheter atrio-ventricular valve prosthesis (<NUM>) for functional replacement of a mitral or tricuspid atrio-ventricular valve (<NUM>) in a connection channel (<NUM>), having a circumferential connection channel wall structure (<NUM>'), between atrial (<NUM>) and ventricular (<NUM>) chambers of a heart (<NUM>), comprising
- an inner device (<NUM>) to be disposed in the interior of the connection channel (<NUM>), the inner device (<NUM>) having a circumferential support structure (<NUM>) which is radially expandable and having a valve (<NUM>) attached to the circumferential support structure (<NUM>),
- and an outer device (<NUM>) to be disposed on the exterior side of the connection channel (<NUM>), wherein the outer device (<NUM>) at least partly extends around the inner device in a radial distance to the inner device, wherein the circumferential support structure (<NUM>) of the inner device (<NUM>), and the outer device form a clamping mechanism for clamping the circumferential connection channel wall structure (<NUM>') of the connection channel (<NUM>) therebetween, characterised in that
- the circumferential support structure of the inner device (<NUM>) is provided, on its outer periphery, with a compressible material or a compressible structure, wherein the outer device is configured to locally compress said compressible material/structure to thereby form a corresponding groove in the compressible material/structure.