Technical Field

The invention relates to a heart implant, particularly a heart implant being configured to reduce or eliminate a heart valve insufficiency after implantation into the heart.

Background of the invention

Typically, such implants are positioned in such a way that a closure element of the implant is situated in the valve annulus and closes a remaining gap of the closed valve leaflets. For that purpose, the closure element is connected to an anchoring element being configured to fix the closure element within the heart in the desired position i.e. in the valve annulus preferably to be contacted by the closing valve leaflets.

It is known in the art to use an anchoring element punctured into the myocardium of the ventricle for fixation of the closure element. Besides this invasive way modern implants provide a less invasive fixation just by contacting the interior wall of the atrium and/or the ventricle with the outer surface areas of an anchoring element formed of an expanded cage that is connected to the closure element. Anchoring elements, particularly the ones formed as a cage may be attached to the closure element on the atrial and/or ventricular side, most preferred only on the atrial side of the closure element. Such cage and closure element typically is in a collapsed state for feeding the entire implant through a catheter into the heart where it is expanded after release from the catheter for fixation purposes.

The invention generally relates to implants having an expandable closure element, no matter how the anchoring element is realized and preferably the invention relates to implants having an expandable closure element attached to an anchoring element formed as a cage of several strips, preferably interconnected strips forming a mesh. A cage may also be formed without meshes, particularly just by several side-by-side-lying strips having no interconnection. The invention in general also relates to non-meshed cages.

Applicants own patent applications having the serial numbers DE 10 2015 005 934.3 and EP 16000475.0 already disclose a heart implant comprising a tubular attachment element for attaching a sheath to it. In these documents the sheath is formed of an inflatable membrane. After attaching, particular fluid tight attaching an inflatable membrane that may be inflated by a liquid the expanded membrane and the tubular attachment element surrounded, preferably coaxially surrounded by the membrane form the aforementioned closure element that is to be positioned in the respective heart valve annulus. The membrane may be made of a flexible or elastic material, preferably a foil. An expanded membrane encircles a space surrounding the tubular attachment element that reduces or eliminates a gap between the leaflets.

In the mentioned state of the art such an inflatable membrane or sheath forms an inflatable balloon to which the leaflets of a valve directly coapt.

The long term durability and resistance to leakage of such fluid-tight fillable closure elements is still to be proven. Particularly there is a risk that calcified leaflets may puncture the balloon / membrane rendering the balloon und thus the entire implant ineffective. Accordingly, it is an object of the invention to provide an implant having a closure element and at least one anchoring element attached to it preferably at least at the atrial side of the closure element that provides for the closure element the necessary long term durability, no problems with possible leakage and preferably also a smooth surface for harmless coaptation between this surface and the closing valve leaflet, preferably of the mitral valve.

Any direction mentioned in this application text is to be understood in relation to the implant correctly implanted in the heart, preferably if the closure element is positioned in the valve annulus, preferably of the mitral valve.

Even though the application of the implant is preferred in regard to humans the implant may be also applied to animals, particularly mammalian animals.

Summary of the invention

The object is solved by a heart implant, particularly being configured to reduce or eliminate a heart valve insufficiency after implantation into the heart, comprising a closure element being positionable within the heart valve annulus, particularly being configured to close or at least to reduce a remaining gap between closing valve leaflets, an anchoring element being attached to the closure element for fixing the implant in the heart, preferably for non-invasive fixing by surface contact between the exterior surface of the anchoring element and an interior surface of a heart lumen, preferably the atrium, wherein the closure element comprises an expandable, fluid-tight and with a fluid fillable balloon, the balloon being

surrounded by a cover means.

According to the invention such cover means protects the balloon, particularly the membrane of which the balloon is made, against direct contact by the leaflets. Accordingly, any calcifications at the leaflets may not harm the balloon material, even after long time. A cover means is preferably in contact with the exterior balloon surface at least after expansion of the balloon. In this situation the cover means is directly supported by the inflated balloon and furthermore stabilized.

The cover means may be made of any material that is capable to withstand long- term coaptation by the leaflets.

According to a preferred embodiment the cover means may be formed of a sheath, preferably a porous sheath, furthermore preferred formed of a flexible membrane being unfoldable / stretchable by the balloon. Such sheath will form the contact surface for the closing leaflets. Possible embodiments and advantages of this sheath are the same as the embodiments and advantages described later for a sheath situated around a scaffold structure and will be explained later.

In another preferred embodiment the cover means that covers the balloon may be formed by an expandable scaffold structure, preferably an expandable stent structure.

A stent structure is understood to be a meshed tubular element, the meshes preferably formed of interconnected struts or wires, particularly made of metal. Such meshed tubular element may be formed by stretching/expanding an axially slotted tube.

The different embodiment of the invention also comprise at least one anchoring element attached to the closure element, that is also expandable, preferably after releasing the implant out of a delivery catheter. Such anchoring element preferably forms a cage as mentioned before.

If a scaffold structure is realized as mentioned the cage is preferably expanded to a bigger cross section compared to the scaffold structure of the closure element. In any way the anchoring cage may provide a compliance / compressibility at least in a radial direction in relation to the longitudinal axis of the closure element in order to provide a force directed towards the myocardium of the lumen (e.g. atrium) in which it is positioned. The non-compressed cross section of such cage is at least slightly larger than the cross section of the lumen.

These features of the invention may provide different advantages. The particularly resilient scaffold structure that totally surrounds the balloon at least in a

circumferential direction provides a long term resistance of the closure element against cyclic force loading by the blood pressure changes and the coapting leaflets. The balloon - no matter whether directly covered by a sheath/membrane or by a scaffold - particularly after inflation with a fluid, preferably a liquid, at least provides an element that supports the chosen cover means and fills its internal volume. Furthermore, the cover means and particularly the scaffold protects the balloon from rupture due to continuous leaflet contact, particularly if the leaflets are calcified.

The expandable scaffold structure, particularly the self-expandable or balloon- expandable scaffold structure may be at least partially covered on its exterior side by a sheath, the sheath forming an exterior contact element for closing leaflets. Accordingly, the leaflets can coapt the scaffold structure without being harmed. Consequently, the covering of the scaffold by a sheath is a very preferred embodiment, but in fact it is not mandatory. Accordingly, all embodiments mentioned for the implant may be also realized without such a covering sheath on top of the scaffold structure.

The sheath of the two different embodiments mentioned before (sheath covering balloon / sheath covering scaffold that covers balloon) may be formed of a fluid tight membrane having no pores and as such a very smooth surface to be contacted by the closing leaflets. Such a surface may form a permanent artificial element that will remain smooth for a long term.

In contrast to this in another embodiment the sheath may also be porous and preferably formed of a flexible membrane being unfoldable / stretchable by the expandable scaffold structure. The porous sheath at least provides a surface structure that promotes

endothelialisation, particularly if the porous sheath furthermore comprises an agent for promoting the endothelialisation. At least after endothelialisation coaptation between the leaflets and the surface of the porous sheath is completely harmless. Such a sheath may form by time a new natural tissue to be contacted by the closing leaflets.

Such a sheath, no matter whether with or without pores, may cover a compressed scaffold structure during the implantation procedure and may be unfolded simultaneously together with the expanding scaffold structure. Expanding of the scaffold structure and preferably also of the at least one anchoring element may preferably automatically take place after release from a catheter, for example if the scaffold structure is made of a shape memory material like nitinol. In such embodiment the sheath may form a cover of the scaffold structure that tightly fits the scaffold surface. The scaffold may also be expanded by means of a balloon catheter in a well-known fashion.

In all the embodiments comprising a balloon contacting the scaffold from the inner side and a sheath contacting the scaffold on the outer side blood may be trapped in the meshes of the scaffold structure that are covered on both sides. In order to prevent this in a preferred embodiment at least a part of the pores of the porous sheath may be configured to allow blood to pass through the pores.

In all of the afore-mentioned embodiments the mentioned porous sheath may be formed of at least one of the following: a textile, preferably a woven, knitted or braided textile, furthermore preferred the textile being made of PET fibers or a surface coating of the scaffold being deposited to the scaffold by means of electrospinning a material solution or material melt, preferably of a polymer or a foil having holes or channels passing through the foil in the direction of the thickness of the foil. In a preferred embodiment the sheath may be formed of a textile being available at the market under the tradename DACRON. The balloon that is intended to support the scaffold structure from the inside in the expanded state of the implant may be inflated with a fluid in order to expand the balloon. The fluid may be filled into the balloon through a valve that may be used to close the balloon after filling. The valve may also be a self-closing check-valve.

If the scaffold is not self-expanding the scaffold will be simultaneously expanded if the balloon expands. This is due to the expanding forces that are exerted from the balloon to the inner side of the scaffold structure. The balloon will maintain inflated during the entire time of therapy.

If there is a need to extract the implant or at least the closure element this may be achieved by releasing the fluid out of the balloon. For this purpose, the balloon may be puncture or an existing valve may be opened to release a harmless fluid into the blood or to release the fluid into a receiving catheter. When the balloon is deflated the scaffold may be compressed and extracted from the heart after separating the scaffold from an anchoring cage. The anchoring cage may remain in the heart if it is grown inti the myocard. If not the anchoring cage may also be compressed and retracted together with the scaffold or alone after separation from the scaffold. A sheath covering the scaffold may be retracted together with the scaffold.

The balloon may be attached at least to the ventricular side of the scaffold structure, preferably also to the atrial side of the scaffold. Consequently, the balloon of the implant is permanently connected to the implant and particularly to the scaffold structure, unless it is separated during explantation.

According to a preferred embodiment the balloon may be formed of a hose having two ends, the two ends, preferably the two neck forming ends of the hose being attached to the atrial and ventricular ends of the scaffold structure respectively. Preferably the atrial neck is permanently closed and preferably the balloon may be filled with a fluid through the open and closable ventricular side. Such a shape of the balloon, i.e. having tapered necks on both sides is particularly chosen if the scaffold structure provides a corresponding tapered shape on its respective atrial and ventricular sides. So the tapered necks of the balloon may fit from the inside into the tapered ends of the scaffold and may be attached to these ends.

In another embodiment the balloon may have only one open end, this open end being attached to the ventricular side of the scaffold structure. The ventricular side of the scaffold structure may comprise a valve, through which the balloon is fillable with a fluid. Preferably such a valve may be integrated into a tubular shaped ventricular end of the scaffold structure.

According to another embodiment the balloon may be attached to a carrier element, the balloon and the carrier element being separate to the scaffold structure and insertable into the scaffold structure preferably also extractable out of the scaffold structure at the ventricular side of the scaffold structure.

In this embodiment the scaffold structure and the attached anchoring element may be implanted first and expanded. Afterwards the separate construction of balloon and carrier element may be inserted into the expanded scaffold structure and inflated. Of course the separate construction of balloon and carrier element may also be implanted simultaneously with the scaffold and the anchoring element and just serve to facilitate later explantation since in that case the balloon construction may be deflated and retracted first and the scaffold and/or anchoring element afterwards.

In a preferred embodiment the carrier element may comprise a tube, the at least one open end, preferably the at least one neck forming open end of the balloon, being attached to the tube.

In an embodiment in which the balloon is formed of a hose having tapered necks the two opposite necks may be attached to the opposite ends of the tube.

Accordingly, the tube is situated in the inner volume of the balloon. The atrial end of the tube is permanently closed. The ventricular end may be closable, preferably by a valve, for example a check valve in order to fill the balloon through it. Such a valve may be integrated into the tube. Preferably at least a part of the surface of the tubular carrier element, that is surrounded by the balloon is perforated.

Consequently, a fluid, like a liquid, may be forced through the ventricular open end of the tube into the balloon. By doing this the fluid also passes through the perforated area of the tube.

In a possible embodiment the cage may be connected to the scaffold structure directly or via an openable link at a tapered part of the scaffold structure, the tapered part having a smaller cross section regarded perpendicular to the imaginary longitudinal axis of the closure element extending between atrium and ventricle compared to the part of the closure element to which the leaflets coapt.

Such tapered part may be formed of a tubular part, preferably a residual tubular part of the tube of which the scaffold structure and/or the anchoring cage are manufactured, preferably by tube slotting and expanding the tube. Such a tapered part of the scaffold structure / a residual tubular part may also or only exist on the ventricular side of the scaffold structure.

According to another possible embodiment at least a part of the strips of the anchoring cage are merging directly or via an openable link into strips that form the scaffold structure of the closure element. In a direction towards the cage the scaffold structure may be expanding in cross section regarded perpendicular to the imaginary longitudinal axis of the closure element and go over into the anchoring cage.

Also in all embodiments, as particularly mentioned at the end opposite the anchoring element the scaffold structure may be tapered and merge into a tubular element, preferably a tubular residual part as explained, the tubular element forming a connector for connecting a handling device. Such handling device may serve to place the implant at the correct position and/or to move it through a catheter. This tubular part may also be used to attach the balloon to it. At the end opposite the anchoring element the strips, particularly free tips of the strips, particularly of two connected strips that form the scaffold structure may be bent towards a central longitudinal axis of the scaffold structure. This provides a tapered ventricular end of the scaffold structure. At the end opposite the anchoring element the free tips of the strips, particularly of two connected strips that form the scaffold structure may also comprise pinholes. The pinholes may serve to connect sutures passing through a catheter or sutures fixing the sheath to the scaffold at this end.

In all embodiments the anchoring element may be at least partially covered with a porous membrane, preferably a textile membrane, preferably at least at the end of the anchoring element opposite the scaffold structure. Such membrane may be formed of the same material as the sheath of the closure element. The membrane may cover free tip ends of strips forming the anchoring cage and may prevent puncturing the myocard during implantation when the implant is not yet expanded and/or may promote tissue ingrowth and thus fixation of the anchoring cage. The membrane may have an annular shape and/or may be connected to the free tips of the strips that form the cage by at least one suture element passing through pinholes in the mentioned tips.

In the afore-mentioned embodiment according to which the scaffold structure has on both sides (atrial and ventricular) tapered tubular parts, particular residual tubular parts of the original tube of which the implant is manufactured, the sheath surrounding the scaffold may be formed of a hose being connected to the tapered part at its respective ends.

Description of the figures

Figure 1 illustrates a first embodiment of the invention having a balloon with two opposite tapered necks

Figure 2 illustrates a second embodiment of the invention having a balloon with just one open end Figure 3 illustrates a third embodiment having a balloon construction being separate to the scaffold and anchoring cage and inserted into them

Figure 4 illustrates a fourth embodiment in which the balloon has just one

open end being connected to a carrier element thus forming also a separate construction

Figure 5 illustrates a fifth embodiment of a separate balloon construction

Detailed description of the invention

Figure 1 illustrates a cross sectional view of an implant according to a first embodiment of the invention. The implant is preferably made of a single tube by laser cutting the tube surface and expanding the slotted tube. After expansion the ventricular part forms a scaffold, particularly stent structure 1 that directly or via an openable like merges at the atrial side A into the anchoring cage 2, that preferably comprises several stripes, particularly interconnected strips 3. The scaffold 1 comprises in this embodiment on the atrial and ventricular side respective tapered, particularly tubular parts 1a, 1 b.

In this embodiment the scaffold 1 is covered at the outside with a preferably porous sheath or membrane 4. Such a membrane is at least wrapped around the scaffold in the areas that are intended for coaptation with the leaflets of a native valve. In this embodiment the sheath 4 is formed of a hose having tapered necks that are connected to the atrial and ventricular tapered tubular parts of the scaffold 4.

On the inside of the scaffold 4 an inflatable balloon 5 is positioned. After inflating the balloon 5 with a fluid the outer surface of the inflated balloon 7 will support the scaffold 4 and provide improved long term stability. Filling may be performed in the direction of arrow 6 through the ventricular opening of the balloon 5, that may be closed by a not shown valve. The balloon may be connected with the outside surface of the necks to the inside surface of the tapered tubular parts 1a, 1 b of the scaffold 4.

In figure 1 and all the other figure the different elements like sheath, scaffold and balloon are shown in a slightly separated fashion just for visibility. In the real implant, particularly after expansion all the elements may contact each other without a distance.

In figure 2 the scaffold structure 1 and anchoring cage 2 are the same as described in figure 1. The cage 2 is not shown. But here the balloon 5 just comprises one open end at the ventricular side of the scaffold 4.

In the embodiments of figure 1 and 2 the balloon 5 is permanently attached to the scaffold structure 4 during implantation and therapy.

Figure 3 shows another embodiment in which the scaffold 4 and anchoring cage 5 are formed in the same kind as described in figures 1 and 2. The anchoring cage is again not shown. But here the balloon 5 is attached to a tubular carrier element 6. These two elements form a construction being separate to the scaffold 4 and cage 5. The construction of balloon 5 and carrier element 6 is inserted into the inner free space of the expanded scaffold. This may be done after expansion of the scaffold 1 , but the deflated balloon 5 may also be positioned in the crimped / compressed scaffold 1 prior to the implantation procedure.

In this embodiment the carrier element 6 is formed of a perforated tube and the balloon 5 is formed of a hose having two opposite tapered necks being attached to the tube ends. The atrial end of the tube may be closed permanently and the ventricular end of the tube may be closable, for example by means of a valve incorporated in the tube end.

The sheath 4 covering the scaffold is wrapped around the circumference of the scaffold only in these positions where the leaflets coapt. Figure 4 shows another embodiment in which the balloon 5 just has one open end on the ventricular side V being connected to a tubular carrier element 6, that preferably incorporates a valve for filling. The balloon 5 and the carrier element 6 again form a separate construction for inserting into the scaffold from the ventricular side.

The scaffold 1 is formed different to the other embodiments of figures 1 to 3. Even though the ventricular side of the scaffoldl is tapered it does not merge into a tubular part but has free tips of the strips that form the scaffold. These free tips of the strips are bent towards the carrier element 6, thus surrounding it.

In Figure 5 the balloon construction corresponds to the one described for figure 3 and the scaffold and anchoring construction corresponds to the one of figure 4.

In this embodiment the scaffold 1 expands at the atrial side and thus forms the anchoring cage 2 by means of bended, preferably interconnected strips 3. These strips 3 form the resilient cage for connecting the inner myocard of the atrium.