WO2022166062A1

WO2022166062A1 - Heart valve anchoring mechanism and heart valve prosthesis device

Info

Publication number: WO2022166062A1
Application number: PCT/CN2021/099451
Authority: WO
Inventors: 赵婧; 刘祥; 闻靖
Original assignee: 上海臻亿医疗科技有限公司
Priority date: 2021-02-03
Filing date: 2021-06-10
Publication date: 2022-08-11
Also published as: CN216318211U

Abstract

A heart valve anchoring mechanism (220) and a heart valve prosthesis (100) device. An end of a heart valve is provided with a connector (210) extending in an axial direction; and the anchoring mechanism (220) is configured to be fixed to an end of the connector (210), and comprises a spacer (221) and an anchoring member, with the spacer (221) comprising a first surface (2211) attached to tissue and a second surface (2212) opposite the first surface (2211), and the anchoring member comprising a plurality of anchoring units (222). The plurality of anchoring units (222) of the anchoring member are respectively attached and anchored to the tissue, and are also attached to the surface of the tissue by means of one surface of the spacer (221); the spacer (221) can provide a relatively large surface area, such that stress concentration can be prevented, and thus preventing the tissue from being worn by the anchoring member; in addition, when the anchoring units (222) are attached to the tissue, an action force is generated for the spacer (221), which action force can make the spacer (221) tightly attach to the tissue, thereby realizing the effects of sealing a wound and enhancing the anchoring, and the matching between the spacer (221) and the anchoring units (222) can provide a better anchoring effect.

Description

A heart valve anchoring mechanism and heart valve prosthesis device

technical field

The utility model belongs to the technical field of medical devices, in particular to a heart valve anchoring mechanism and a heart valve prosthesis device.

Background technique

Transcatheter mitral valve replacement (TMVR) is a method of catheter intervention. The artificial valve is compressed into the delivery system outside the body, along the vascular path or through the apex, to the human mitral valve annulus, and the artificial valve is released. It is fixed at the mitral valve annulus to replace the native valve. Compared with surgery, TMVR does not require extracorporeal circulation auxiliary devices, has less trauma, quicker recovery of patients, and significantly improved postoperative hemodynamic indicators.

Despite the rapid development of mitral valve replacement technology, there are still some recognized challenges in valve design, such as valve anchoring. Some of the existing mitral valve designs use clipping leaflets or grasping the valve leaflets for anchoring, both of which will pull the chordae tendineae and cause damage to the native valve leaflets. There is also anchoring through the Oversize design of the stent body. With this anchoring method, the stent compresses the tissue, which affects the contraction of the heart, and there is a risk of conduction block. There are also attempts to anchor by connecting a plate-shaped spacer to the end of the pull rope, but the spacer alone cannot form an effective anchorage.

Therefore, it is particularly necessary to design a reliable anchoring structure for the mitral valve or tricuspid valve.

Utility model content

The utility model provides a heart valve anchoring mechanism and a heart valve prosthesis device, which can solve the above-mentioned defects in the prior art.

The technical scheme of the present utility model is as follows:

A heart valve anchoring mechanism for anchoring a heart valve, the end of the heart valve is provided with an axially extending connector, the anchoring mechanism is configured to be fixed to the end of the connector, the anchoring mechanism It includes a spacer including a first surface attached to the tissue and a second surface opposite the first surface and an anchor, the anchor including a plurality of anchoring units secured to the the second surface.

The plurality of anchoring units of the anchor are respectively attached and anchored to the tissue, and are also attached to the tissue surface through one surface of the spacer. The spacer can provide a relatively large surface area, which can prevent stress concentration and prevent the anchor from affecting the tissue. In addition, when the anchoring unit is attached to the tissue, a force will be generated on the spacer, and the force can make the spacer and the tissue adhere closely, thus playing the role of sealing the wound, which is beneficial to the anchoring of the anchoring mechanism. ; Through the cooperation of the spacer and the anchoring unit, a better anchoring effect can be provided.

In some embodiments, the spacer is configured to conform to the morphology of the apical epicardium. Such a structure enables the spacer to always closely adhere to the apical epicardium during the cardiac cycle, which is beneficial to the anchoring of the anchoring mechanism and the tissue, and at the same time, it also has a good occlusion effect.

In some embodiments, the first surface of the spacer is configured to protrude in a direction away from the heart valve, and the spacer is attached to the apical epicardium through the protruding first surface away from the apex, so that the spacer can be more adapted to the outside of the heart. Morphology of the membrane to reduce stress damage to the apical portion.

In some embodiments, the spacer is configured as a frame structure, and the surface of the spacer is further provided with a coating layer. The frame structure can make the spacer have a certain flexibility to adapt to the dynamic cardiac circulation, and the membrane layer has a certain sealing effect to prevent blood penetration.

In some embodiments, the spacer is configured as a sheet-like structure, which has the advantage of being simple to form.

In some embodiments, the anchoring unit is configured to bulge in a direction away from the heart valve. With such a structure, the anchor can be adapted to the external shape of the entire ventricle, the anchoring unit can better grasp the tissue, and the anchoring is firm.

In some embodiments, the anchoring unit is configured such that one end is connected to the second surface, the other end first extends to a side away from the heart valve, and then bends to extend toward the heart valve side, and the end fit with the organization.

In some embodiments, the anchoring unit is made of shape memory material. Therefore, the anchoring unit can be crimped into the delivery device for delivery, and can return to its original state for anchoring after being released to the target location.

In some embodiments, the center of the spacer is configured with a central hole for fixing the connector.

In some embodiments, a plurality of the anchoring units are evenly distributed along the center circumference of the second surface of the second spacer to provide stable anchoring force, and the anchoring units are fixed between the central hole and the spacer Between the edges of the anchoring unit, the end of the anchoring unit is attached to the tissue through a spacer to prevent damage to the tissue by the end of the anchoring unit.

The utility model also provides a heart valve prosthesis device using any of the heart valve anchoring mechanisms described above.

Compared with the prior art, the beneficial effects of the present utility model are as follows:

First, in the anchoring mechanism and the heart valve prosthesis device of the present invention, the multiple anchoring units of the anchor are respectively attached and anchored to the tissue, and are also attached to the tissue surface through one surface of the spacer, and the spacer can provide relative Large surface area to prevent stress concentration and wear of the anchor to the tissue; in addition, when the anchor unit is attached to the tissue, a force will be generated on the spacer, which can make the spacer adhere tightly to the tissue, thereby It plays the role of sealing the wound and enhancing the anchoring effect; through the cooperation of the spacer and the anchoring unit, it can provide a better anchoring effect.

Second, in the anchoring mechanism and the heart valve prosthesis device of the present invention, the spacer is attached to the apical epicardium through the first surface protruding away from the centrifugal apex, and the spacer is configured in a manner that conforms to the shape of the apical epicardium during the cardiac cycle , so that the spacer can be more adapted to the shape of the apical epicardium, so as to reduce the stress damage to the apical part, and the spacer can be closely attached to the apical epicardium, which is beneficial to enhance the anchoring effect of the anchoring mechanism and the tissue.

Third, in the anchoring mechanism and the heart valve prosthesis device of the present invention, the anchoring unit is configured to protrude toward the direction away from the heart valve, and such a structure can make the anchor fit the external shape of the entire ventricle, The anchoring unit can better grasp the tissue, and the anchoring is firm.

Fourth, the heart valve prosthesis device of the present invention can be delivered by the atrial septal route. Compared with the apical route, the atrial septal route through the femoral vein is less traumatic and has a wider audience.

Of course, it is not necessary for any product implementing the present invention to simultaneously achieve all of the above-mentioned advantages.

Description of drawings

1 is a schematic diagram of the overall structure of the heart valve prosthesis device according to Embodiment 1 of the present invention;

2A is a schematic diagram of the overall structure of the anchoring mechanism of Embodiment 1 of the present invention;

2B is a cross-sectional structural schematic diagram of the anchoring mechanism of Embodiment 1 of the present invention;

2C is a schematic diagram of the overall structure of a spacer according to Embodiment 1 of the present invention;

3A is a schematic diagram of the overall structure of another anchoring mechanism according to Embodiment 1 of the present invention;

3B is a cross-sectional structural schematic diagram of the anchoring mechanism of Embodiment 1 of the present invention;

4A is a schematic structural diagram of the initial stage of implantation of the heart valve prosthesis device according to Embodiment 1 of the present invention;

4B is a schematic structural diagram of the release stage of the heart valve prosthesis device according to Embodiment 1 of the present invention;

4C is a schematic structural diagram of the heart valve prosthesis device released according to Embodiment 1 of the present invention;

Reference numerals: valve prosthesis 100; first region 101; second region 102; third region 103; stent 110; ventricular anchor 200; Q; first surface 2211; second surface 2212.

Detailed ways

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner" and "outer" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, with a specific orientation. Therefore, it should not be construed as a limitation on the present invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a connectable connection. Detachable connection, or integral connection; may be mechanical connection or electrical connection; may be direct connection, or indirect connection through an intermediate medium, or internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The present utility model will be further described below in conjunction with specific embodiments.

Example 1

This embodiment provides a heart valve prosthesis device, see FIGS. 1-4C , which are schematic structural diagrams of this embodiment, wherein the heart valve prosthesis device is composed of a valve prosthesis 100 (also referred to as a heart valve) and a The ventricular anchoring part 200 is composed of the valve prosthesis 100 including the stent 110, the skirt and the artificial valve leaflets.

As shown in FIG. 1 , the heart valve prosthesis device of this embodiment can be longitudinally divided into a first region 101 , a second region 102 and a third region 103 . After implantation into the human body, the first region 101 is attached to the original mitral valve. On the valve annulus, to prevent the valve prosthesis 100 from falling into the left ventricle from the left atrium, the second area 102 is used to carry the artificial valve leaflets, and at the same time relies on the support on the tissue to play a certain role in fixing and sealing; the third area 103 is The anchoring mechanism of the heart valve in the left ventricle prevents the prosthesis from being impacted by blood to the left atrium when the prosthesis is closed.

Among others, stent 110 can provide several functions for valve prosthesis 100, including serving as the main structure of the valve, carrying internal prosthetic leaflets, serving as a seal to inhibit paravalvular leakage between valve prosthesis 100 and the native valve, and delivering The connection structure of the system (hanging ears or fixed ears), etc. Optionally, the stent 110 is woven or cut. Optionally, the stent 110 is made of nickel-titanium alloy or other biocompatible materials with shape memory properties, and elastically or plastically deformable materials, such as balloons, can also be selected. Expandable material.

Further, the bracket 110 is a columnar structure with open ends, such as a cylinder, an ellipse column, etc., and its cross-section is configured as a circle, an ellipse, a petal shape, a round shape, a D shape, and the like. The stent 110 is constructed as a grid-like structure, which is composed of a number of closed geometric cells arranged, such as diamond, square, heart, teardrop, etc., so that the stent 110 can be compressed into the sheath when loaded, and can be recovered when released. undisturbed.

The prosthetic leaflets are dynamically switched between open and closed states, in which the prosthetic leaflets are closed or joined in sealing abutment. The prosthetic valve leaflets can be formed from any suitable material or combination of materials, and in some embodiments, biological tissue such as chemically stable tissue from a heart valve from an animal such as a pig, or pericardial tissue from an animal such as bovine (bovine pericardium) or sheep (sheep pericardium) or pig (porcine pericardium) or equine (horse pericardium), preferably bovine pericardium tissue. Prosthetic leaflets can also be made from small intestinal submucosal tissue, in addition, synthetic materials can also be used for the prosthetic leaflets, such as expanded polytetrafluoroethylene or polyester; Ether urethanes, segmented polyether urethanes, silicone polyether urethanes, silicone-polycarbonate urethanes, and ultra-high molecular weight polyethylene. Additionally, biocompatible polymers can be used for prosthetic valve leaflets, optionally including polyolefins, elastomers, polyethylene glycol, polyethersulfone, polysulfone, polyvinylpyrrolidone, polyvinyl chloride , other fluoropolymers, silicone polyesters, siloxane polymers and/or oligomers, and/or polylactones, and block copolymers using them. Optionally, the prosthetic leaflets have a surface that is treated (or reacted with) an anticoagulant, including, but not limited to, heparinized polymers.

The skirt can be a single-layer structure, or a double-layer structure inside and outside. Knitted, woven, woven polyester fabrics, PTFE, ePTFE and other materials can be selected, which mainly play the role of sealing and prevent backflow.

In some embodiments, the ventricular anchoring portion 200 includes an anchoring mechanism 220 and a connector 210. As shown in FIG. 1, the connector 210 extends in the axial direction of the heart valve and is disposed at the end of the stent 110, and the anchoring mechanism 220 is fixed to the connector. the end of the piece 210. Wherein, the extension structure extending from the end points of several rhombus geometric units at one end of the stent 110 is connected with the end of the connecting piece 210 , such as suture connection. The connecting member 210 provides traction for the stent 110 to prevent the stent 110 from being displaced to the left ventricle due to the impact of blood when the heart contracts. The connector 210 may be, for example, a pull cord, wire, or rod-like structure, etc., and may be made of, for example, a biocompatible polymeric material including, but not limited to, ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene, and the like. The connector 210 may be inelastic to provide a more robust stent anchoring force, or elastic to provide a higher degree of stretch compliance during the cardiac cycle. Alternatively, the connector 210 may be made of a bioabsorbable material and thereby provide temporary fixation until endothelialization between the prosthesis and assembly is sufficient to provide an anchoring force for the valve prosthesis. Optionally, the connecting member includes a pulling rope, a connecting wire or a connecting rod, and the like.

In the embodiment shown in FIG. 2A to FIG. 3B , the anchoring mechanism 220 includes a spacer 221 and an anchor, and the spacer 221 includes a first surface 2211 and a second surface 2212 opposite to the first surface 2211 , The anchor includes a plurality of anchor units 222 secured to the second surface 2212 .

In this embodiment, the plurality of anchoring units 222 of the anchor are respectively attached and anchored to the tissue, and are also attached to the tissue surface through one surface of the spacer 221. The spacer 221 can provide a relatively large surface area, which can prevent stress concentration, Prevent the wear of the multiple anchoring units to the tissue; in addition, when the anchoring unit 222 is attached to the tissue, it will generate a force on the spacer 221, and the force can make the spacer 221 closely adhere to the tissue, so as to block The role of the wound is also beneficial to enhance the anchoring stability of the anchoring mechanism 220 . In this embodiment, better anchoring effect can be provided through the cooperation between the spacer 221 and the anchoring unit 222 .

In some embodiments, the first surface 2211 of the spacer 221 is configured to bulge away from the heart valve. The anchoring unit 222 is fixed on the second surface 2212 of the spacer 221 , the first surface 2211 of the spacer 221 is curved around the apical epicardium and roughly conforms to the outer surface of the apex, and the end of the anchoring unit 222 is in contact with the tissue through the spacer 221 , to reduce stress damage to the apex of the heart from the ends of the plurality of anchoring units 222 .

In some embodiments, the spacer 221 is configured in a manner that conforms to the morphology of the apical epicardium during the cardiac cycle. Specifically, the spacer 221 is sufficiently flexible, for example, the spacer 221 is configured as a semi-rigid semi-elastic structure, or a flexible structure, which can conform to the apical portion of the heart during a dynamic cardiac cycle, so that it always closely fits the apex during the cardiac cycle The outer membrane provides excellent occlusion effect, and at the same time makes the anchoring mechanism 220 firmly anchored.

In the embodiment shown in FIG. 2C , the spacer 221 is configured as a frame structure, and the surface of the spacer 221 is further provided with a coating layer. The frame structure enables the spacer 221 to have good flexibility to accommodate dynamic cardiac circulation, and the frame structure can be more easily crimped into the delivery device for delivery. Wherein, the frame structure can be cut, manufactured or woven, and the frame structure can be prepared from nickel-titanium alloy, stainless steel, carbon fiber and other materials. The coating layer can be made of impermeable materials, such as polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polypropylene, polyester, animal pericardial tissue, etc. The coating layer can prevent blood penetration.

In some embodiments, the spacer 221 is configured as a sheet-like structure, as shown in FIG. 2A and FIG. 2B , the sheet-like structure has the advantage of being simple to form, and at the same time, the sheet-like structure can provide better sealing, keep it with the tissue close adhesion between. The spacer 221 of this embodiment can be selected from soft and biocompatible materials such as PE, PTFE, silica gel, etc., thereby reducing the probability of rejection reaction, reducing the wear and tear of cardiac tissue, and thereby improving the safety of patients.

Further, the anchor includes three or more anchoring units 222. In some embodiments, the anchoring units 222 are configured to protrude in a direction away from the heart valve. That is, the anchoring unit 222 is configured as an anchor claw structure, one end of the anchoring unit 222 extends toward the second surface 2212 of the spacer 221 , and the other end extends toward the direction of the heart valve. The anchoring unit forms the anchor hook structure of the ship anchor. A smooth arc transition is adopted between the extension structures of the anchoring unit 222 in two directions, and an arc-shaped curved surface is formed between the anchoring units 222 . Such a structure can make the anchor fit the shape of the entire ventricle, better grasp the tissue, and thus form a better anchoring force.

Specifically, the anchoring unit 222 is made of a shape memory material, such as a shape memory alloy (nickel-titanium alloy), or a shape memory polymer material. Therefore, the anchoring unit 222 can be crimped into the delivery device for delivery, and can return to the original state for anchoring after being released to the target position.

In some embodiments, the center of the spacer 221 is configured with a central hole Q for fixing the connecting piece 210 , and the connecting piece 210 is fixed through the central hole Q with a wire knot.

In some embodiments, a plurality of anchoring units 222 are evenly distributed along the circumferential direction of the spacer 221, so that the anchors can provide stable and effective anchoring force; and one end of the anchoring units 222 is fixed in the central hole Q Between the edge of the spacer 221 and the edge of the spacer 221 , one end of the anchoring unit 222 will not be in contact with the tissue for friction, so as to prevent stress concentration, and at the same time, the strength of the spacer 221 will not be affected. Wherein, the free end of the anchoring unit 222 is configured to have a smooth surface to prevent damage to the tissue.

In some embodiments, the anchoring unit 222 and the spacer 221 are manufactured separately, and then fixed by welding or the like. In some embodiments, the anchoring unit 222 and the spacer 221 can be manufactured integrally, such as by cutting.

The anchoring mechanism 220 and connector 210 of this embodiment are capable of resisting retrograde forces applied to the heart valve prosthetic device during ventricular systole to maintain the desired position of the heart valve on the native mitral valve. Of course, in other embodiments, the anchoring mechanism 220 can also be used for anchoring the tricuspid valve.

The heart valve prosthesis device of this embodiment can be delivered by the atrial septal route. Compared with the apical route, the atrial septal route through the femoral vein is less invasive and has a wider audience. Under the transatrial septal path, the anchoring mechanism 220 can be anchored in the apex, and can also be anchored in the ventricular wall. In the present embodiment, the anchoring in the apex is used as an example to illustrate. Specifically, the implantation method of this heart valve prosthesis device is as follows:

Step 1: As shown in Figure 4A, the delivery 201 enters the right atrium via the inferior vena cava, then passes through the atrial septum and the mitral valve to the vicinity of the apex of the heart, as shown, the distal end of the delivery 201 can pass through the apex of the heart opening.

Step 2: As shown in Figure 4B, the anchoring mechanism 220 is released by relative movement between it and a portion of the delivery 201 (eg, catheter or sheath). By relative movement is meant that the anchoring mechanism 220 can be advanced through the catheter or sheath and out of the distal end of the delivery device 201 to be released. Further movement between the anchoring mechanism 220 and the catheter or sheath can effectively deploy the location of the anchoring mechanism 220, eg, pulling the anchoring mechanism 220 proximally against the tip of the heart, which can be done by pulling the suture or connector 210 to execute.

Step 3: As shown in Figure 4C, the catheter or sheath can be moved relative to the stent 110, releasing the stent 110, allowing the valve prosthesis to be fully released at the target location. For example, the catheter or sheath can be withdrawn proximally relative to the stent 110 . In some embodiments, the length of the connector 210 can be modified at this stage or any previous stage to adjust the tension of the connector 210 to allow the anchoring mechanism 220 to achieve an optimal anchoring force. Finally, the connector 210 is fixed and cut, and then the delivery system is withdrawn to complete the release.

Although this example only describes the method in relation to the native mitral valve, it can similarly be used for other native heart valves (eg, the tricuspid valve).

In some embodiments, the above-mentioned heart valve prosthetic device can also be delivered via the apical approach, specifically, the implantation method is as follows:

Step 1: The delivery device 201 can be advanced through the tip of the heart to the vicinity of the native mitral valve. The catheter or sheath is moved relative to the stent 110, gradually releasing the stent 110, skirt, and prosthetic valve leaflets, allowing the valve prosthesis to be deployed at the target location. The position of the valve prosthesis can be adjusted by the connector 210 .

Step 2: The sheath can be moved proximally relative to the stent 110 such that the distal end of the catheter or sheath is positioned outside the heart. The anchoring mechanism 220 is released by relative movement between it and the catheter or sheath of the delivery 201 . By relative movement is meant that the anchoring mechanism 220 can be advanced in a direction towards the heart (distal end) through the catheter or sheath. When the anchoring mechanism 220 extends beyond the sheath or catheter, the anchoring mechanism 220 is slowly released. Further movement between the anchoring mechanism 220 and the catheter or sheath can effectively deploy the position of the anchoring mechanism 220, fully releasing the anchoring mechanism 220 at or near the apex of the heart. In some embodiments, the length of the connector 210 can be modified at this stage or any previous stage to adjust the tension of the connector 210 to allow the anchoring mechanism 220 to achieve an optimal anchoring force.

Step 3: Finally, fix and cut the connector 210, and then withdraw from the conveying system to complete the release.

The above disclosure is only the preferred embodiments of the present invention, and the preferred embodiments do not describe all the details in detail. It should be understood that these embodiments are only used to illustrate the Novel types are limited only by the claims and their full scope and equivalents.

This specification selects and specifically describes these embodiments in order to better explain the principle and practical application of the present invention, so that those skilled in the art can make good use of the present invention. Improvements and adjustments made by those skilled in the art according to the present invention in practical applications still belong to the protection scope of the present invention. In addition, the technical features in the above different embodiments can be arbitrarily combined on the premise that there is no conflict with each other.

Claims

A heart valve anchoring mechanism for anchoring a heart valve, the end of the heart valve is provided with a connecting piece extending in the axial direction, the anchoring mechanism is configured to be fixed to the end of the connecting piece, and characterized in that: The anchoring mechanism includes a spacer including a first surface attached to the tissue and a second surface opposite the first surface and an anchor, the anchor including a plurality of anchoring units, the anchoring A unit is secured to the second surface, and the anchoring unit is anchored in conformity with tissue.
The heart valve anchoring mechanism according to claim 1, wherein the spacer is arranged to conform to the shape of the apical epicardium.
2. The heart valve anchoring mechanism of claim 1 or 2, wherein the first surface of the spacer is configured to bulge in a direction away from the heart valve.
The heart valve anchoring mechanism according to claim 1, wherein the spacer is configured as a frame structure, and the surface of the spacer is further provided with a coating layer.
The heart valve anchoring mechanism of claim 1, wherein the spacer is configured as a sheet-like structure.
The heart valve anchoring mechanism of claim 1, wherein the anchoring unit is configured to bulge in a direction away from the heart valve.
The heart valve anchoring mechanism according to claim 6, wherein the anchoring unit is configured such that one end is connected to the second surface, and the other end first extends to a side away from the heart valve, and then bends toward the side of the heart valve. One side of the heart valve is extended and the end is attached to the tissue.
The heart valve anchoring mechanism according to claim 1, wherein the anchoring unit is made of shape memory material.
The heart valve anchoring mechanism according to claim 1, wherein a center hole for fixing the connecting member is disposed at the center of the spacer.
The heart valve anchoring mechanism according to claim 9, wherein a plurality of the anchoring units are evenly distributed along the center circumference of the second surface of the second spacer, and the anchoring units are fixed between the center hole and the center hole. between the edges of the spacer.
A heart valve prosthesis device employing the heart valve anchoring mechanism according to any one of claims 1-10.