Patent Description:
Main causes of valve diseases include rheumatic fever, mucinous degeneration, intervertebral disc degeneration, congenital malformation, ischemic necrosis, infection, trauma and the like, which may cause lesion of a single valve or multiple valves. The valvular lesion generally includes stenosis or insufficiency. The stenosis generally means that the opening of the valve is narrowed to decrease blood entering the next heart chamber. The insufficiency means that the valve does not close fully and there is backflow of part of the blood. The stenosis and/or the insufficiency would obstruct normal blood flow to increase the corresponding heart burden, thus causing impairment to normal functions of the heart and leading to cardiac failure and changes of functions of multiple visceral organs of organisms. There are two main surgical therapies for treating heart valve diseases at the present: <NUM>) valvuloplasty, used for repairing a damaged valve, and <NUM>) valve replacement, used for replacing the damaged valve with an artificial mechanical valve or a bioprosthetic valve. And there are two surgical pathways which are surgical operation and minimally invasive intervention.

The surgical operation is a common method for replacing or repairing a diseased or damaged valve. A defective heart valve is replaced by an artificial valve, and a low-calcified valve is repaired or rebuilt. However, high complications and high mortality rate are significant defects of the surgical operation. In recent years, percutaneous and minimally invasive valve implantation surgical methods have been developed. The percutaneous and minimally invasive surgical methods are to implant valves into lesion locus through sheaths to reduce and avoid traumas and relevant complications of the surgical operation.

<CIT> discloses a leaflet prosthetic valve device comprising a leaflet frame and one or more leaflets coupled to the frame by means of frame projections. The projections are configured to extend through an aperture defined in a leaflet attachment region at the frame edge. The projections can be disposed on one or more leaflet retention surfaces, which are defined opposite the leaflet frame edges, either externally or internally.

For example, the patent application No. <CIT> discloses a minimally invasive implanted artificial valve device. As shown in <FIG>, a valve <NUM> is provided with a framework <NUM>, a leaflet <NUM>, an inner skirt <NUM> and an outer skirt <NUM>. The leaflet <NUM> includes three lobules <NUM>. Multiple fixing holes <NUM> spaced from one another are formed in the framework <NUM> in a circumferential direction. Upper protruding portions <NUM> of two lobules <NUM> are downwards folded, and lower protruding portions <NUM> of the two lobules <NUM> are inserted into the fixing holes <NUM> and extend out of the outer circumferential surface of the framework <NUM>. The portion, extending out of the outer circumferential surface, of each lower protruding portion <NUM> is sutured to the corresponding upper protruding portion <NUM> with a main suture <NUM> to form a sutured portion <NUM> of a valve strut as shown in <FIG>.

This valve device has the following defects that: the sutured portion <NUM> of the valve strut is relatively thick, so that a relatively thick delivery sheath is needed to deliver the valve device, which increases the risk of damage to a blood vessel by the sheath in a surgical procedure and also leads to an inapplicability of the valve to a patient with relatively thin blood vessels.

An object of the present invention is to provide an artificial heart valve device having a smaller size and longer service life, so as to overcome the defects in the prior art.

According to the present invention, an artificial heart valve device is provided as defined in claim <NUM>. The device comprises a tubular stent body having an inflow end, an outflow end and hollows, a leaflet arranged in a cavity of the stent body, and fixing structures connected with the stent body and used for fixing the leaflet on the stent body. The leaflet includes at least two valve lobules and a connecting portion connecting two adjacent valve lobules. The fixing structures are arranged in the hollows, and include fixing rods and main bodies connected with the stent body. The main bodies are provided with through holes. At least part of each fixing rod is located in each through hole. One end of each fixing rod is connected with each main body, and the other end of the fixing rod is a free end pointing to the outflow end. Each connecting portion passes through each through hole and is hung on the free end to fix the leaflet on the stent body.

In one embodiment of the present application, each main body is of an approximate U shape with two ends directly connected with the stent body.

In one embodiment of the present application, each main body is of an approximate U shape with two ends connected with the stent body through elastic pieces.

In one embodiment of the present application, each main body is of a closed ring shape, and the end, not connected with the fixing rod, of the body is connected with the stent body.

In one embodiment of the present application, the stent body includes multiple waveform ring-like portions arranged along an axial direction of the stent body, and two adjacent waveform ring-like portions are matched with each other to form the multiple closed hollows.

In one embodiment of the present application, each main body is located at a wave crest or a wave trough of the stent body.

In one embodiment of the present application, the part, close to each through hole, of each main body is further provided with protruding portions protruding towards each fixing rod, and the protruding portions are respectively located on two sides of the fixing rod.

In one embodiment of the present application, the surfaces, close to the fixing rod, of the protruding portions are of arc shapes or wave shapes.

In one embodiment of the present application, accommodating holes communicated with the through holes are also formed in the stent body; the end portions of the free ends are located in the accommodating holes; and gaps are reserved between the free ends and the stent body.

In one embodiment of the present application, each fixing rod includes a first fixing rod and a second fixing rod which are both located in each through hole. One end of the first fixing rod is connected with each body, and the free end of the first fixing rod points to the outflow end. One end of the second fixing rod is connected with the stent body, and the free end of the second fixing rod points to the inflow end.

In one embodiment of the present application, each fixing rod includes a first part extending in each through hole from each body along a direction parallel to the axis of the stent body, and a second part extending from the tail end of the first part along a direction close to the axis of the stent body.

In one embodiment of the present application, the positive projection of each fixing structure in a plane perpendicular to the axial direction of the stent body does not exceed the positive projection of the outer contour of the stent body in the same plane.

In one embodiment of the present application, the width of the end, connected with each body, of each fixing rod is greater than that of the free end.

In one embodiment of the present application, the artificial heart valve device further includes a skirt structure connected with the stent body. The skirt structure includes at least one of an atrium side skirt or a ventricle side skirt.

In one embodiment of the present application, the outer edge of the leaflet is further covered by a reinforcing layer.

In one embodiment of the present application, the stent body includes multiple waveform ring-like portions arranged along an axial direction of the stent body. Each closed framework is encircled by wave crests and wave troughs of two adjacent waveform ring-like portions. One end of each fixing rod is connected with the wave troughs, and the free end of the fixing rod points to the wave crests.

In one embodiment of the present application, the stent body includes multiple waveform ring-like portions arranged along an axial direction of the stent body and spaced from one another, and connecting rods located between two connected waveform ring-like portions and connecting the two adjacent waveform ring-like portions. Each closed framework is encircled by two adjacent waveform ring-like portions and each connecting rod. One end of each fixing rod is connected with the wave troughs, and the free end of the fixing rod points to the wave crests.

The present invention also provides a stent body, as defined in claim <NUM>.

The stent body of an artificial heart valve device comprises an inflow end, an outflow end and hollows and including fixing structures for fixing a leaflet. The fixing structures are arranged in the hollows, and include fixing rods and main bodies connected with the stent body. Each main body is provided with a through hole. At least part of each fixing rod is located in the through hole. One end of each fixing rod is connected with each main body, and the other end of the fixing rod is a free end pointing to the outflow end.

The fixing structures of the present application do not protrude from the pipe wall of the stent body. During assembling of the leaflet, only the connecting portions are hung on the fixing rods, so that the maximum outer diameter of the compressed valve is reduced, the size of a delivery sheath required by the valve is decreased, and the risk of damage to a blood vessel by the sheath in surgery is lowered. In addition, the requirement of the interventional valvular surgery for the size of a blood vessel of a patient is lowered, and the application scope of interventional valves is expanded.

The present application will be further described below in combination with the accompanying drawings, which illustrate embodiments. In the drawings:.

To understand the present application more clearly, specific embodiments are now described in conjunction with the accompanying drawings.

As shown in <FIG>, an artificial heart valve device <NUM> includes a tubular stent body <NUM> having an inflow end 10A and an outflow end 10B, fixing structures <NUM> connected with the stent body <NUM> and a leaflet <NUM> arranged in a cavity of the tubular stent body <NUM>. The stent body <NUM> is used for fixing the leaflet <NUM> and providing a radial tension to fix the artificial heart valve device <NUM> into a heart tissue at the same time. The leaflet <NUM> serves as a one-way valve and limits a one-way blood flow from the inflow end 10A to the outflow end 10B so as to achieve the effect of a human valve.

A stent body <NUM> may be made of a biocompatible plastic expansion material known in the art such as medical stainless steel or a cobalt-chromium alloy, or made of a self-expandable material such as a nickel-titanium alloy. A stent body <NUM> made of a plastic expansion material may be compressed radially in a delivery sheath and is expanded to an initial shape and size through an inflatable balloon or an equivalent expansion mechanism. A stent body <NUM> made of a self-expandable material may be compressed radially in the delivery sheath and recovers the initial shape and size in the absence of the compression of the delivery sheath. A stent body <NUM> may be cut from a tube or woven from a metal wire.

A stent body <NUM> of the present embodiment is cut from a superelastic or shape memory nickel-titanium metal tube through laser while a tube has a diameter range of <NUM>-<NUM> and a thickness range of <NUM>-<NUM>, and the cut shape and structure are as shown in <FIG>. As shown in <FIG>, the stent body <NUM> includes multiple waveform ring-like portions <NUM> and <NUM> arranged along the axis of the stent body <NUM>. The waveform phases of the waveform ring-like portions <NUM> and <NUM> are opposite, that is, the wave crests of the waveform ring-like portion <NUM> are opposite to the wave troughs of the waveform ring-like portion <NUM>. The waveform ring-like portions <NUM> and <NUM> are connected through connecting points <NUM> so as to form multiple closed frameworks <NUM> arranged along a circumferential direction of the stent body <NUM>. Each closed framework <NUM> is encircled by one wave crest of the waveform ring-like part <NUM> and one wave trough, opposite to the wave crest, of the waveform ring-like part <NUM> and has a hollow <NUM>.

In addition, in the present embodiment, the inner and outer circumferential surfaces of a stent body <NUM> are covered by coating membranes. In other possible embodiments, only one of the inner and outer circumferential surfaces is covered by a coating membrane. Specifically, referring to <FIG> and <FIG>, the outer circumferential surface is covered by an outer coating membrane <NUM>, and the inner circumferential surface is covered by an inner coating membrane <NUM>. These inner and outer coating membranes are used for preventing streaming of blood flow at the hollows <NUM> of the stent body <NUM>. An inner coating membrane <NUM> and an outer coating membrane <NUM> may be made of macromolecular materials with relatively high biocompatibility, such as ePTFE (e-polytetrafluoroethylene), PET (polyethylene glycol terephthalate) or PCU (polycarbonate polyurethane) and an animal pericardial tissue. A coating membrane may be in various forms, such as membranes, woven cloth, woven meshes, knitted fabrics, knitted nets and nonwoven cloth. An inner coating membrane <NUM> and an outer coating membrane <NUM> may be fixed onto a stent body <NUM> by a conventional process in the art, such as suturing, gluing and thermal covering, and may adopt different materials and forms or adopt the same materials and forms. For example, an inner coating membrane <NUM> is a PTFE woven mesh, and an outer coating membrane <NUM> is an ePTFE membrane. These two membranes are integrated at the hollows <NUM> of a stent body <NUM> through thermal covering, so as to fix the stent body <NUM> between them. Therefore, good suture performance may be achieved by use of the strength of the PTFE cloth, and leakage of the artificial heart valve device may be prevented by use of the good leakproofness of the ePTFE membrane.

To further improve the suture performance of a leaflet <NUM>, the leakproofness of a stent body <NUM> and the bonding strength between coating membrane layers as well as the bonding strength between a coating membrane layer and a stent body <NUM>, a middle layer <NUM> may be added between an inner coating membrane <NUM> and a stent body <NUM> or between an outer coating membrane <NUM> and a stent body <NUM>. As shown in <FIG>, in the present embodiment, a middle layer <NUM> is arranged between an outer coating membrane <NUM> and a stent body <NUM>. A middle layer <NUM> may be single-layer or multilayer, and may be a woven mesh formed by PTFE wires, or a plain or oblique woven mesh tube arranged on the outer circumferential surface of a stent body <NUM> in a sleeving manner and formed by a PTFE wire. As shown in <FIG>, a middle layer <NUM> has a thickness range of <NUM>-<NUM> and is woven from two strands of PTFE wires <NUM>. A mesh <NUM> has an average width <NUM> range of <NUM>-<NUM>, and the PTFE wire <NUM> has an average wire width range of <NUM>-<NUM>.

An inner coating membrane <NUM> and an outer coating membrane <NUM> both adopt an ePTFE membranes having thickness range of <NUM>-<NUM>, each of which is composed of <NUM> to <NUM> layers. A middle layer <NUM> is clamped between a stent body <NUM> and an outer coating membrane <NUM>. The coating membranes, the middle layer and the stent body are fused together through a hot pressing method. At the hollows <NUM> of the stent body <NUM>, the inner coating membrane <NUM>, the middle layer <NUM> and the outer coating membrane <NUM> are fused together. The inner coating membrane <NUM> and the outer coating membrane <NUM> are fused together through the meshes <NUM> of the middle layer <NUM>. To increase the bonding force of the coating membranes and the stent body <NUM>, a PTFE coating layer or a Parylene coating layer may be deposited or sprayed on the surface of the stent body <NUM>.

<FIG> are respectively a planar graph of a leaflet <NUM> expanded in a natural state and a stereo installation state diagram. In the present embodiment, a leaflet <NUM> is composed of three valve lobules <NUM> of same shapes and sizes and three connecting portions <NUM> of same shapes and sizes. Two adjacent valve lobules <NUM> are connected together through each connecting portion <NUM>. The three valve lobules <NUM> respectively have bottom edges 121a, 121b and 121c, and are enclosed in the center of a leaflet <NUM> to form an approximately equilateral triangle-shaped center hole <NUM>. The three valve lobules <NUM> form a leaflet body. Further, the three valve lobules <NUM> and the three connecting portions <NUM> are integrated, that is, each connecting portion <NUM> is part of the leaflet <NUM>. As shown in <FIG>, to improve the suture performance of the leaflet <NUM>, a reinforcing layer <NUM> may be added at the edge of the leaflet <NUM>. A reinforcing layer <NUM> covers the edge of the leaflet <NUM> and then is fixed through a suture <NUM>. A reinforcing layer <NUM> may be made of ultrahigh molecular weight polyethylene, PET, nylon, PU, PCU and the like, and may be of different forms, such as a membrane and a woven fabric. A leaflet <NUM> is cut from an animal pericardium (such as a bovine pericardium or pig pericardium subjected to chemical curing treatment) or a macromolecular material (such as a PTFE membrane or cloth, an ultrahigh molecular weight polyethylene membrane or cloth, an aramid fiber membrane or cloth, a PCU membrane or cloth) through laser, a cutting die, a hydro jet or scissors and the like, and a cut form is as shown in <FIG>.

The outer contour line of the body of a leaflet is of an approximate regular triangle shape and has three smooth vertex angles. Each connecting portion <NUM> protrudes from the outer contour lines <NUM> of two valve lobules connected with the connecting portion. It is worth noting that each connecting portion <NUM> also may not exceed the outer contour lines <NUM>. These three valve lobules <NUM> in a planar expanded state are arranged in a centrosymmetric manner along the circumferential direction of the stent body <NUM>. The whole leaflet <NUM> is in mirror symmetry along each symmetry line <NUM>. The valve lobules <NUM> are downwards folded along the symmetry lines <NUM>, and then the bottom edges 121b and 121c of two adjacent valve lobules <NUM> are aligned and fitted with each other to obtain an installation form of a leaflet <NUM> as shown in <FIG>. An installed leaflet <NUM> has an effect similar to that of a one-way valve. The center hole <NUM> forms a blood flow channel, and the leaflet <NUM> allows the blood flow to flow from the inflow end 10A to the outflow end 10B, but does not allow the blood flow to flow from the outflow end 10B to the inflow end 10A. This is because when the blood flow flows from the outflow end 10B to the inflow end 10A, the three valve lobules <NUM> may get close towards the center under the action of blood pressure to close the center hole <NUM>. On the contrary, the blood flow would flush to disperse the three valve lobules <NUM> towards a direction away from the center when flowing from the inflow end 10A to the outflow end 10B to open the center hole <NUM>.

The connecting portions <NUM> are symmetric along the symmetry lines <NUM>, and the end close to the outflow end 10B of each connecting portion <NUM> is closed, and the end close to the inflow end 10A of the connecting portion <NUM> is open. The folded connecting portions <NUM> are fixedly connected with the fixing structures <NUM> of the stent body <NUM>. Referring to <FIG> and <FIG> together, except the bottom edges 121b and 121c, the edges of other parts of the valve lobules <NUM> are fixed at the inflow end 10A of the coated stent body <NUM> through sutures.

As shown in <FIG> and <FIG>, in the present embodiment, a stent body <NUM> has wave crests <NUM>. A fixing structure <NUM> includes a main body <NUM> and a fixing rod <NUM>. A main body <NUM> is of an approximate U shape with two ends directly connected with a wave crest <NUM> and is provided with a through hole <NUM>. A fixing rod <NUM> is arranged in each through hole <NUM>. One end of a fixing rod <NUM> is connected with a main body <NUM>, and the other end of a fixing rod <NUM> is a free end pointing to the outflow end.

A fixing structure <NUM> is located in a hollow <NUM>, and is connected with the wave crest part of a waveform ring-like portion <NUM> close to the outflow end 10B and does not protrude from the inner wall and the outer wall of a stent body <NUM>. The maximum width of a fixing structure <NUM> in a radial direction of a stent body <NUM> is less than or equal to the wall thickness of the stent body. That is to say, the positive projection of a fixing structure <NUM> in a plane perpendicular to the axial direction of the stent body <NUM> is located in the positive projection of the outer contour of the stent body <NUM> on the same plane. In other embodiments, a fixing structure <NUM> also may be connected with the wave trough part of a waveform ring-like portion <NUM>. A fixing rod <NUM> has a fixed end 132a connected with a main body <NUM> and a free end 132b extending from the fixed end 132a towards the outflow end 10B, and a gap is reserved between the free end 132b and the wave crest <NUM>. It can be understood that a free end 132b also may be in contact with a wave crest <NUM>. A fixing rod <NUM> is located at the middle position in a main body <NUM>, and the axis of a fixing rod <NUM> is approximately parallel to that of the stent body <NUM>. Referring to <FIG> and <FIG> together, the open end of a connecting portion <NUM> may pass through a through hole <NUM> and bypass the free end 132b of a fixing rod <NUM>, and the closed end of the connecting portion <NUM> is flush with the free end 132b to connect the connecting portion <NUM> to the fixing rod <NUM> in a sleeving manner. In other embodiments, a connecting portion <NUM> also may be of a barrel-shaped structure with one open end and one closed end. In addition, to further fix a connecting portion <NUM>, enhance the connection between a connecting portion <NUM> and a fixing rod <NUM> and prevent the connecting portion <NUM> from falling off from the fixing rod <NUM>, the connecting portion <NUM> may be fixed on the outer surface of the fixing rod <NUM> in a glue dispensing manner and the like. In the present embodiment, to further fix a connecting portion, two end portions of the folded connecting portion <NUM> are sutured with sutures. A U-shaped through hole <NUM> has a groove width ranging between <NUM> and <NUM> which approximates to the thickness of the leaflet <NUM>, and achieves an effect of fixing a connecting portion <NUM>. A fixing rod <NUM> having a width ranging between <NUM> and <NUM> does not protrude from the pipe wall of the stent body <NUM> and is used for hanging a connecting portion <NUM>. The length of a fixing rod <NUM> is approximately equal to the maximum length of a connecting portion <NUM> on the symmetry axis of the corresponding leaflet body. Under reverse blood flow pressure, a leaflet <NUM> provides a radial tension for each connecting portions <NUM> to prevent a prolapse of a valve lobule <NUM>.

On one hand, a fixing structures <NUM> of the present application are directly formed in a hollows <NUM> of the stent body, and a connecting portions <NUM> protrude from the contour line of the body of a leaflet <NUM> and may be folded to form a structure with one open end and one closed end; and after being folded along the center axis of the body of the leaflet, the connecting portions <NUM> may be directly hung on the fixing rods <NUM> to fix the leaflet <NUM> into the cavity of the stent body <NUM> and form a valve strut at the fixing rods <NUM>. Compared with the prior art as shown in <FIG>, an artificial heart valve provided by the present application has the advantages that a leaflet <NUM> neither needs to extend out of the outer circumferential surface of a stent body <NUM> from fixing holes <NUM> to be folded nor needs to cover the stent body near a fixing holes <NUM> to be sutured at the valve strut, that is, the thickness of an artificial heart valve provided by the present application at a valve strut is approximately equal to the sum of the thicknesses of a connecting portions <NUM> and the thicknesses of a fixing rods <NUM>, so that an artificial heart valve may be used cooperatively with a relatively thin delivery sheath, and the risk of damage to a blood vessel by a sheath in a surgical procedure is lowered. In addition, the requirement of the interventional valvular surgery for the size of a blood vessel of a patient is lowered, and the application scope of interventional valves is expanded.

On the other hand, a leaflet of the present application does not have sutures for connecting valve lobules. The assembling is very simple as only folded connecting portions are enabled to pass through through holes <NUM> and are arranged into fixing rods in a sleeved manner from the free ends of fixing rods. Furthermore, as the main body and the wave crest part of the waveform ring-like portion form a closed accommodating space to limit the movement of the leaflet in the axial direction and the axial prolapse of the leaflet is avoided, the connecting portions are not required to be sutured and fixed after being arranged into the fixing rods in the sleeved manner. Since the connecting portions are not required to be sutured and fixed, no pin holes would be produced, so that the mechanical strength and the fatigue life of the leaflet are improved. In addition, the connecting portions may be fixed through the through holes of the main bodies, the fixing rods and the wave crest parts without introducing other fixing structures, so that unnecessary affiliated fixing structures are reduced, and the maximum outer diameter of the compressed valve is decreased to the maximum extent, and adverse effects on a human body caused by the protruding affiliated fixing structures are also avoided.

As shown in <FIG>, an artificial heart valve device <NUM> may further include a skirt structure <NUM> connected with the stent body <NUM>. When an artificial heart valve device <NUM> is applied to a mitral valve or a tricuspid valve, a skirt structure <NUM> is needed on the basis of the artificial heart valve device <NUM> to prevent occurrence of perivalvular leakage. As shown in <FIG>, the skirt structure <NUM> includes an atrium side skirt <NUM> and a ventricle side skirt <NUM>, or only includes one side skirt. The atrium side skirt <NUM> and the ventricle side skirt <NUM> are connected through a waist portion <NUM>.

An atrium side skirt <NUM> includes an atrium side skirt stent <NUM> and a flow resisting body covering the atrium side skirt stent, and has a closed end <NUM> and a free end <NUM> extending from the closed end <NUM> towards the inflow end 10A. Similarly, a ventricle side skirt <NUM> also includes a ventricle side skirt stent <NUM> and a flow resisting body covering the ventricle side skirt stent, and has a closed end <NUM> and a free end <NUM> extending from the closed end <NUM> towards the outflow end 10B. The extension of the free end towards the inflow end 10A is to avoid a cutting effect between it and a peripheral tissue of the atrium. The closed end <NUM> of an atrium side skirt stent <NUM> is connected with the closed end <NUM> of a ventricle side skirt stent <NUM> through a waist portion stent <NUM> welded on the stent body <NUM>. By the arrangement of the flow resisting bodies on the atrium side skirt stent <NUM>, the ventricle side skirt stent <NUM> and the waist portion stent <NUM>, a better perivalvular leakage avoided effect may be achieved. Each flow resisting body may be various materials, such as an animal pericardium, PTFE, high molecular weight polyethylene, PET, nylon, PU and PCU, and also may be of various forms, such as a membrane, a woven fabric, a knitted fabric and nonwoven cloth. The flow resisting bodies may be fixed on the stent in various ways of suturing, thermal covering, gluing and the like.

In addition, to facilitate connection of an artificial heart valve device having a skirt to a delivery system, at least one of the ventricle side skirt stent <NUM> and the atrium side skirt stent <NUM> is provided with connecting structures <NUM>. In the present embodiment, connecting structures <NUM> are connecting rings arranged along the circumferential directions of the respective free ends of the atrium side skirt stent <NUM> and the ventricle side skirt stent <NUM> in a spacing manner.

As shown in <FIG>, in another embodiment of the present application, a stent body includes multiple closed frameworks <NUM>' encircled by two adjacent waveform ring-like objects <NUM>' and <NUM>' having opposite phases and has hollows <NUM>'. The fixing rods <NUM> are located in the hollows <NUM>'. One end of each fixing rod is connected with the wave trough of each framework <NUM>', and the free end of the fixing rod points to the outflow end.

As shown in <FIG>, in another embodiment of the present application, a stent body includes multiple closed frameworks encircled by two adjacent waveform ring-like objects having opposite phases and has hollows <NUM>. Each fixing structure <NUM> is arranged in a hollow <NUM> and includes a closed annular main body <NUM> and a fixing rod <NUM>. Each main body <NUM> is provided with an approximately U-shaped through hole <NUM>. One end of each fixing rod <NUM> is connected with each main body <NUM>, and the other end of the fixing rod <NUM> is a free end pointing to the outflow end. The end, not connected with the fixing rod <NUM>, of each main body <NUM> is connected with one wave crest of the stent body.

It can be understood that in other embodiments of the present application, each fixing structure <NUM> is still located in a hollow <NUM>, but is connected with one wave trough of the stent body <NUM> as long as the free end of each fixing rod <NUM> points to the outflow end.

<FIG> is a structural schematic diagram of a second embodiment of a fixing structure in a artificial heart valve device of the present application. In the present embodiment, a fixing structure is located in the closed framework of a stent body as shown in <FIG> and also includes a main body connected with one wave crest of a stent body and provided with a through hole, and a fixing rod located in the through hole and extending from the main body towards the outflow end. The fixing structure of the present embodiment has the same effect as the fixing structure <NUM> as shown in <FIG>, but a difference lies in that in the present embodiment, the fixing rod is approximately triangular, like a fan. Specifically, the width W1 of the fixed end of a fixing rod is greater than the width W2 of the free end. The fixing rod divides the fixing structure into an inverted V-shaped accommodating groove having an equal groove width to accommodate the connecting portion. The connecting portion <NUM> of the leaflet <NUM> is of a fan-shaped structure (as shown in <FIG>), so that the similarly fan-shaped fixing rod may be well matched with the connecting portion <NUM> to enable the connecting portion <NUM> to well cover the outer side of the stent body <NUM> without producing protrusions and further decrease the maximum diameter of the compressed valve.

<FIG> show structural schematic diagrams of a third embodiment of a fixing structure in a artificial heart valve device of the present application. In the present embodiment, the fixing structure <NUM>' also includes a main body <NUM>', a through hole <NUM>' and a fixing rod <NUM>' located in the through hole <NUM>' and extending from the main body <NUM>' towards the outflow end and has the same effect as the fixing structure <NUM> as shown in <FIG>. But a difference lies in that the length of the fixing rod <NUM>' is greater than that of an accommodating slot <NUM>' along the axial direction of the stent body. In the present embodiment, the wave crest part of the stent body is further provided with an accommodating hole <NUM>' communicated with the through hole <NUM>'. The free end <NUM>'b of a fixing rod <NUM>' extends into the accommodating hole <NUM>', and a gap is reserved between the free end <NUM>' and the stent body <NUM> so as to move the free end <NUM>' during subsequent fixing of the leaflet and to reset the free end <NUM>' after the leaflet is fixed. The accommodating hole <NUM>' is specifically formed in the wave crest part of the waveform ring-like portion <NUM>, that is, the wave crest part is inwards sunken to form the above-mentioned accommodating hole <NUM>'. The width of the gap between the free end 132b' and the wave crest part is equal to the size of a laser light spot and is <NUM>-<NUM>. The free end <NUM>'b of the fixing rod <NUM>' may be turned out from the gap to hang the connecting portion <NUM> of the leaflet <NUM>. In addition, thanks to the gap being much smaller than the thickness of the leaflet <NUM> and the effect of a stop portion <NUM>' on the stent body <NUM>, the connecting portion <NUM> of the leaflet <NUM> may be prevented from falling off from the fixing rod <NUM>'.

<FIG> is a structural schematic diagram of a fourth embodiment of a fixing structure in a artificial heart valve device of the present application. A difference from the third embodiment only lies in that in the present embodiment, the width of the fixed end <NUM> of a fixing rod <NUM> is greater than that of the free end <NUM> of the fixing rod <NUM> so as to better adapt to the similarly fan-shaped structure of the connecting portion <NUM>.

As shown in <FIG>, in the present embodiment, a fixing structure <NUM>' includes a main body <NUM>' connected with the stent body <NUM>, a through hole <NUM>' and a fixing rod located in the through hole <NUM>'. In the present embodiment, the fixing rod includes a first fixing rod <NUM>' and a second fixing rod <NUM>'. The first fixing rod <NUM>' extends from the main body <NUM>' towards the outflow end 10B along the axis of the stent body <NUM>. One end of the second fixing rod <NUM>' is connected with one wave crest of the stent body <NUM>, and the other end of the second fixing rod <NUM>' is a free end and extends towards the inflow end 10A along the axis of the stent body <NUM>. A gap <NUM>' is reserved between the free ends of the first fixing rod <NUM>' and the second fixing rod <NUM>'. The connecting portion <NUM> of the leaflet <NUM> passes through the through hole <NUM>' through the gap <NUM>' and then is hung on the first fixing rod <NUM>' and the second fixing rod <NUM>'. When hung on the first fixing rod <NUM>' and the second fixing rod <NUM>', the connecting portion <NUM> of the leaflet <NUM> is very hard to fall off from the first fixing rod <NUM>' and the second fixing rod <NUM>' under any forces in any axial directions, so that the risk that the connecting portion <NUM> of the leaflet <NUM> falls off from the fixing rod is lowered.

As shown in <FIG>, in the present embodiment, a fixing structure <NUM> also includes an approximately U-shaped main body <NUM> with two ends directly connected with one wave crest <NUM> of the stent body, and a fixing rod <NUM> located in a through hole <NUM> of the main body <NUM> and extending from the main body <NUM> towards the outflow end 10B. A difference from above-mentioned embodiments lies in that the surface, close to the through hole <NUM>, of the main body <NUM> is further provided with protruding portions <NUM> protruding towards the fixing rod <NUM>. The protruding portions <NUM> respectively located on two sides of the fixing rod <NUM> have arc-shaped outer surfaces which may not puncture the connecting portion <NUM> of the leaflet <NUM>.

The protruding portions <NUM> narrow the through hole <NUM> on two sides of the fixing rod <NUM>. The protruding portions <NUM> may outwards expand appropriately when clamping the connecting portion <NUM> of the leaflet <NUM> and provide an inwards counteractive clamping force for the connecting portion <NUM> of the leaflet <NUM> at the same time, and this clamping force may reduce the slippage of a connecting portion <NUM> of a leaflet <NUM> in a through hole <NUM> and lower the risk that a connecting portion <NUM> falls off from a fixing rod <NUM>.

As shown in <FIG>, in the present embodiment, the structure of a fixing structure <NUM>' is basically the same as that of the sixth embodiment. A difference lies in that in the present embodiment, the wavy outer surfaces of protruding portions <NUM>' may disperse the clamping force of protruding portions <NUM>' on a connecting portion <NUM> of a leaflet <NUM>, so that excessive partial stress on the connecting portion <NUM> would be avoided when the connecting portion <NUM> is clamped.

As shown in <FIG>, a fixing structure <NUM> also includes a main body <NUM> connected with one wave crest <NUM> of the stent body and a fixing rod <NUM> located in a through hole <NUM> of the main body <NUM> and extending from the main body <NUM> towards the outflow end 10B. A difference from above-mentioned embodiments lies in that two ends of the main body <NUM> are connected with the wave crest of the waveform ring-like portion <NUM> through elastic pieces <NUM>. The elastic pieces <NUM> may extend under a tensile force and then restore initial shapes in the absence of a force. The elastic pieces <NUM> may be springs, or integrated Σ-shaped structures molded at two ends of the main body <NUM> through laser cutting as shown in the present embodiment.

As shown in <FIG>, when the elastic pieces <NUM> are in the initial shapes, the free end of the fixing rod <NUM> is in contact with the wave crest of the waveform ring-like portion <NUM> or the gap (less than the thickness of the leaflet <NUM>) is extremely small. As shown in <FIG>, when the elastic pieces <NUM> are in the tensile states under a force, the gap between the free end of the fixing rod <NUM> and the wave crest of the waveform ring-like portion <NUM> is enlarged, and at the moment, the connecting portion <NUM> of the leaflet <NUM> may be hung on the fixing rod <NUM>. Under unstressed condition, the elastic pieces <NUM> restore the initial shapes as shown in <FIG>, and at the moment, the free end of the fixing rod <NUM> is in contact with the wave crest part of the waveform ring-like portion <NUM> or the gap is extremely small, so that the risk that the connecting portion <NUM> of the leaflet <NUM> falls off from the fixing rod <NUM> may be lowered.

As shown in <FIG>, a fixing structure <NUM> also includes a main body <NUM> connected with one wave crest <NUM> of the stent body and a fixing rod <NUM> located in a through hole <NUM> of the main body <NUM> and extending from the main body <NUM> towards the outflow end 10B. A difference from above-mentioned embodiments lies in that the fixing rod <NUM> includes a first part <NUM> extending in the through hole <NUM> from the main body <NUM> along a direction parallel to the axis L of the stent body <NUM>, and a second part <NUM> extending from the tail end of the first part <NUM> along a direction close to the axis L of the stent body <NUM>. It can be seen from <FIG> that the axis L2 of the second part <NUM> is parallel to the axis L of the stent body <NUM>, but is closer to the axis L of the stent body <NUM> than the axis L1. That is to say, the first part <NUM> is overlapped with the outer contour of the stent body <NUM>, and the second part <NUM> protrudes from the inner wall of the stent body <NUM> and is located in a cavity of the stent body <NUM>.

This "inwards sunken" structure of a fixing rod <NUM> allows a connecting portion <NUM> to be hung more easily. When the connecting portion <NUM> of a leaflet <NUM> is hung on a fixing rod <NUM>, the protruding size of the outer side of the connecting portion <NUM> is decreased, which may reduce the difficulty of putting an artificial valve into a sheath and lower the risk of damage to the artificial valve in the processes of putting the artificial valve into the sheath and delivering the artificial valve.

It can be understood that in other embodiments of the present application, a fixing structure having an approximately U-shaped main body as shown in <FIG>, <FIG> and <FIG> may be located outside the closed framework structure. For example, as shown in <FIG>, the fixing structure is located at the open wave trough of the stent body.

In addition, as shown in <FIG>, a stent body may further include multiple waveform ring-like portions <NUM> and <NUM> arranged along the axial direction of the stent body and spaced from one another, and connecting rods <NUM> located between two connected waveform ring-like portions <NUM> and <NUM> and connecting the two adjacent waveform ring-like portions <NUM> and <NUM>. Each closed framework is encircled by the two adjacent waveform ring-like portions <NUM> and <NUM> and each connecting rod <NUM>. One end of each fixing rod <NUM> is connected with the wave troughs of each waveform ring-like portion <NUM>, and the other end of the fixing rod <NUM> points to the wave crests.

Furthermore, as shown in <FIG>, on the basis of the structure as shown in <FIG>, the main body <NUM> of the structure as shown in <FIG> and <FIG> also may be added, and a fixing rod <NUM> is changed into the structures as shown in <FIG> and <FIG>, thus obtaining the fixing structure located at the wave trough as shown in <FIG>. However, a difference from <FIG> is that two ends of the main body are required to be connected to the wave trough <NUM>.

Claim 1:
An artificial heart valve device, comprising a tubular stent body (<NUM>) having an inflow end (10A), an outflow end (10B) and hollows (<NUM>), a leaflet (<NUM>) arranged in a cavity of the stent body (<NUM>), and fixing structures (<NUM>) connected with the stent body (<NUM>) and configured for fixing the leaflet (<NUM>) on the stent body (<NUM>), and the leaflet (<NUM>) comprises at least two valve lobules and a connecting portion (<NUM>) connecting two adjacent valve lobules; wherein the fixing structures (<NUM>) are arranged in the hollows (<NUM>) and each fixing structure comprises a fixing rod (<NUM>) and a main body (<NUM>) connected with the stent body (<NUM>); wherein one end of the fixing rod (<NUM>) is connected with the main body (<NUM>), and the other end of the fixing rod (<NUM>) is a free end
characterized in that the main body (<NUM>) is provided with a through hole (<NUM>); at least a part of the fixing rod (<NUM>) is located in the through hole (<NUM>); wherein the free end of the fixing rod (<NUM>) points to the outflow end (10B) of the stent body; and the connecting portion (<NUM>) passes through the through hole (<NUM>) and is hung on the free end to fix the leaflet (<NUM>) on the stent body (<NUM>).