Transcatheter artificial atrioventricular valve

Abstract

The collapsible and expandable prosthetic atrioventricular valve may include an outer stent, an inner stent, and a plurality of prosthetic leaflets mounted within the inner stent. The outer stent may have an atrial disk, a ventricular disk, and a plurality of posts connecting the atrial disk to the ventricular disk. A plurality of connectors may extend between the inner and outer stents to connect the inner stent to the outer stent. The outer stent may be free of metal in a space extending circumferentially between adjacent ones of the plurality of posts. The space may extend about one-half, about one-third, or about one-quarter of the circumference of the outer stent.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to the filing date of U.S. Provisional Patent Application No. 63 / 280,673, filed on November 18, 2021, the disclosure of which is incorporated herein by reference.

Background Art

[0002] The heart has four native valves, including the aortic valve, the pulmonary valve, the mitral valve (also known as the left atrioventricular valve), and the tricuspid valve (also known as the right atrioventricular valve). When these valves are not fully joined and dysfunction begins, such as allowing blood to flow backward (or regurgitate) through the valve, it may be desirable to repair or replace the valve. An artificial replacement heart valve may be surgically implanted by open - chest, open - heart surgery while the patient is on cardiopulmonary bypass. However, such surgery is very invasive, and frail patients who are most likely to need an artificial heart valve may have a low chance of surviving such surgery. Recently, artificial heart valves have tended to shift to less invasive procedures, such as foldable and expandable heart valves that can be delivered through the vasculature by a transcatheter procedure.

[0003] The aortic and pulmonary valves are typically relatively circular in shape and have a relatively small diameter compared to the left and right atrioventricular valves. As a result, transcatheter artificial heart valves designed for the mitral and tricuspid valves may have significantly greater challenges to overcome compared to transcatheter artificial heart valve designs for the aortic and pulmonary valves.

[0004] Another challenge in the design of transcatheter artificial atrioventricular valves is to avoid or limit conduction disorders. When a transcatheter artificial atrioventricular valve is expanded into the native mitral or tricuspid valve, the device may compress tissue and cause a disorder in the heart's native conduction system. For this reason, a pacemaker is often implanted along with the artificial atrioventricular valve to nullify such conduction disorders.

[0005] Another challenge in the design of a transcatheter artificial atrioventricular valve is to enable the artificial valve to be recaptured (e.g., refolded within the delivery device) after at least partial expansion. The typical size of an artificial atrioventricular valve is relatively large and may include both an outer fixed frame and an inner valve frame, so the force required to recapture the artificial atrioventricular valve is relatively large and such recapture can be relatively difficult. SUMMARY OF THE INVENTION

[0006] The present disclosure generally relates to foldable and expandable artificial atrioventricular valves that can limit conduction disorders while providing effective fixation. These valves are considered optimal for replacing native mitral valves, particularly native tricuspid valves. These transcatheter artificial atrioventricular valves may generally include a foldable and expandable stent and a foldable and expandable valve assembly coupled to the stent. The stent may generally include an outer stent aimed at achieving fixation within the native valve annulus and an inner stent aimed at generally providing support for the bioprosthetic valve leaflets of the valve assembly. The inner stent may be substantially cylindrical and may be attached to the outer stent in such a way that the bioprosthetic valve assembly can maintain a substantially cylindrical shape even when the shape of the outer stent is distorted by a force applied to the outer stent. The valve assembly may include a plurality of bioprosthetic valve leaflets (typically three leaflets, although two leaflets or more than three leaflets may be provided). The valve assembly may include one or more skirts or cuffs on the inner and / or outer surfaces of the inner and / or outer stents to help provide a seal between the inside of the native valve annulus and the outside of the bioprosthetic valve leaflets.

[0007] According to one aspect of the present disclosure, a foldable and expandable artificial atrioventricular valve includes an outer stent having an atrial disk, a ventricular disk, and a plurality of posts coupling the atrial disk to the ventricular disk, and an inner stent. A plurality of connectors can extend between the inner stent and the outer stent to couple the inner stent to the outer stent. A plurality of artificial valve leaflets may be attached within the inner stent. The outer stent may have no metal in a circumferentially extending space between adjacent ones of the plurality of posts, and this space extends about one-third of the circumference of the outer stent. The atrial disk may have two circumferential cell rows, and the ventricular disk may have one circumferential cell row. The atrial disk may have one circumferential cell row, and the ventricular disk may have two circumferential cell rows. The plurality of posts includes three posts, and each of the three posts includes two struts extending from the atrial disk to the ventricular disk. Each of the two struts of each of the three posts may have a first end coupled to a first vertex of each cell of the atrial disk and a second end coupled to a second vertex of each cell of the ventricular disk. Each of the three posts may include teeth between the two struts. An opening may be formed in one of the two struts or in the teeth of each of the three posts, and each of the plurality of connectors is coupled to the outer stent through one of the corresponding openings. In the expanded state of the artificial atrioventricular valve, the diameter of the outer stent at the plurality of posts may be smaller than the diameter of the outer stent at the atrial disk and the ventricular disk. The inner stent may include a circumferential row of first cells having a total number, and the outer stent can include a circumferential row of second cells having a total number, and the total number of the second cells is an integer multiple of the total number of the first cells. The total number of the second cells is 27, and the total number of the first cells is 9.

[0008] According to a second aspect of the present disclosure, a method of replacing a native atrioventricular valve of the heart may include delivering an artificial atrioventricular valve to the native atrioventricular valve while the artificial atrioventricular valve is folded within a delivery catheter. The artificial atrioventricular valve includes an outer stent, an inner stent coupled to the outer stent, and a plurality of artificial valve leaflets attached within the inner stent. The artificial atrioventricular valve may be deployed from the delivery catheter such that the artificial atrioventricular valve can self-expand. Enabling the artificial atrioventricular valve to self-expand may include positioning an atrial disk of the outer stent on the atrial side of the native atrioventricular valve and positioning a ventricular disk of the outer stent on the ventricular side of the native atrioventricular valve. After the artificial atrioventricular valve self-expands onto the native atrioventricular valve, a gap in the outer stent between an adjacent pair of posts connecting the atrial disk to the ventricular disk may be aligned with the cardiac conduction system.

[0009] According to a third aspect of the present disclosure, an artificial atrioventricular valve system may include an outer stent having an atrial portion and a ventricular portion, an inner stent, a plurality of connectors extending between the inner stent and the outer stent and coupling the inner stent to the outer stent, and a plurality of artificial valve leaflets attached within the inner stent. The outer stent may include one or more circumferential cell rows and a plurality of rails extending axially from the atrial portion to the ventricular portion. The cells of the one or more circumferential cell rows of the outer stent may be diamond-shaped. Each of the plurality of rails may include a connector at its end. At least one flexible control member may be coupled to the connector of each of the plurality of rails. The flexible control member may be a suture. In a retracted state of the artificial atrioventricular valve system, the outer stent may be at least partially deployed from the delivery catheter, and the flexible control member may extend proximally through the interior of the delivery catheter.

[0010] According to a fourth aspect of the present disclosure, a method of recapturing an artificial atrioventricular valve may include delivering the artificial atrioventricular valve to a native atrioventricular valve while the artificial atrioventricular valve is folded within a delivery catheter. The artificial atrioventricular valve includes an outer stent having an atrial portion and a ventricular portion, an inner stent coupled to the outer stent, and a plurality of artificial valve leaflets mounted within the inner stent. The outer stent includes one or more circumferential cell rows and a plurality of rails extending axially from the atrial portion to the ventricular portion. The artificial atrioventricular valve may be deployed from the delivery catheter such that the artificial atrioventricular valve is at least partially self-expanding. The artificial atrioventricular valve may be retrieved into a retrieval catheter after at least partially self-expanding the artificial atrioventricular valve. Retrieving the artificial atrioventricular valve includes folding the artificial atrioventricular valve into the retrieval catheter by manipulating at least one flexible control member coupled to a plurality of connectors, each of the plurality of connectors being coupled to a corresponding one of the plurality of rails. The retrieval catheter may be the delivery catheter. The retrieval catheter may be a separate device from the delivery catheter, and the retrieval catheter may be advanced along or through the delivery catheter after deploying the artificial atrioventricular valve from the delivery catheter and before retrieving the artificial atrioventricular valve.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0012] Figure 1 is a schematic diagram of the right atrioventricular valve (commonly called the tricuspid valve). The tricuspid valve separates the right atrium RA (right atrium) from the right ventricle RV (right ventricle) and usually has three cusps including a posterior leaflet PL, an anterior leaflet AL, and a septal leaflet SL. The septal cusp SL is located closest to the interventricular septum IVS. The tricuspid annulus may include a conduction node, such as the atrioventricular ("AV: atrioventricular") node, near the connection point between the annulus and the septal cusp. An electrical impulse may be conducted from the atrioventricular node through the bundle of His to Purkinje fibers that provide electrical conduction to the ventricles. Papillary muscles PM (Papillary muscles) along the right ventricular wall RVW support the chordae tendineae attached to the tricuspid cusps and prevent inversion of the cusps during normal physiological operation. The left atrioventricular valve (commonly called the mitral valve) has many differences (for example, usually includes two cusps (anterior cusp and posterior cusp) including the mitral valve, and the general shape is a hyperbolic paraboloid or "saddle" type shape), but generally may have a structure similar to the tricuspid valve. Both the mitral annulus and the tricuspid annulus may be very large compared to the aortic valve and the pulmonary valve. For example, in patients with moderate tricuspid valve disease, the diameter of the tricuspid valve may be 45-50 mm, and in patients with severe tricuspid valve disease, the diameter may be 50-60 mm. Depending on the stage of tricuspid regurgitation, the diameter of the tricuspid annulus may expand up to 70 mm.

[0013] Figure 2 is a side perspective view of the outer stent 100 of an artificial atrioventricular valve according to one aspect of the present disclosure. Figure 2 shows the outer stent 100 separated from the rest of the artificial heart valve, omitting structures such as the inner stent and the tricuspid valve leaflets carried by the inner stent, and one or more seal cuffs and / or skirts on the inner and / or outer surfaces of the inner and / or outer stents. The outer stent 100 of Figure 2 is foldable and expandable and may be formed of a shape memory metal such as nitinol. The outer stent 100 of Figure 2 may be substantially circular (and / or rotationally symmetric) when in the illustrated expanded state. The outer stent 100 may include one or more cell rows (e.g., diamond-shaped cells) within an atrial disk section 110 (also referred to as an atrial flare or atrial anchor section) and one or more cell rows (e.g., diamond-shaped cells) within a ventricular section 120 (sometimes referred to as a ventricular flare or ventricular anchor section). In the illustrated embodiment, the atrial section 110 includes two rows of diamond-shaped cells including a first cell row 110a and a second cell row 110b located downstream (outflow direction) of the first cell row 110a. In the illustrated embodiment, the ventricular section 120 includes a single row of diamond-shaped cells 120a. However, in other embodiments, the atrial section 110 may include more or fewer cell rows, the ventricular section 120 may include multiple cell rows, and the cells may form shapes other than diamond-shaped.

[0014] The atrial section 110 may be coupled to the ventricular section 120 only at selected positions around the outer stent 100, leaving a substantial space 140 with no metal stent structure in the circumferential direction between these connection points. In FIG. 2, the connection points include three double clips 130. As shown, the double clips 130 are arranged at equidistant positions along the circumference of the outer stent 100, although in other embodiments the arrangement may not be equidistant. Each double clip 130 may include a first substantially axial stent post 130a extending from the upper apex of the first ventricular stent cell 120a of the second row 110b to the lower apex of the first atrial stent cell, and a second substantially axial stent post 130b extending from the upper apex of the second ventricular stent cell 120a to the lower apex of the second atrial stent cell of the second row 110b. The first atrial stent cell may be directly adjacent to the second atrial stent cell, and the first ventricular stent cell may be directly adjacent to the second ventricular stent cell. When three double clips 130 are provided, the space 140 without a metal stent structure extends approximately one-third of the circumference of the outer stent 100 (although slightly less depending on the size of the double clips 130). If two double clips 130 are provided, the space 140 without metal stent material will be approximately half of the circumference of the outer stent 100. If four double clips 130 are provided, the space 140 without metal stent material will be approximately one-fourth of the circumference of the outer stent 100, etc.

[0015] In the embodiment shown in FIG. 2, the atrial disk 110 includes two rows of stent cells 110a, 110b each having 27 cells, and the ventricular disk 120 includes one row of stent cells 120a having 27 cells. However, as described above, more or fewer rows may be provided in the atrial section 110, and more rows may be provided in the ventricular section 120. In some embodiments, in order to minimize the amount of structure extending into the right ventricle (or left ventricle), and thus to minimize the amount of structure available to block the right ventricular outflow tract ("RVOT: right ventricular outflow tract") (or left ventricular outflow tract ("LVOT: left ventricular outflow tract")), it may be desirable for the ventricular section 120 to have fewer rows. In some embodiments, particularly when the inner stent (any of the inner stents described below, similar or the same) includes rows of 3 or 9 cells (or multiples thereof), it may be desirable for each row 110a, 110b, 120a to include a number of cells that is a multiple of 3 or 9, such a correspondence being able to maximize the ability to provide regular positioning of the members coupling the inner stent to the outer stent 100. However, it should be understood that each row 110a, 110b, 120a may be provided with more or fewer than 27 cells. Also, when the inner stent includes a number of cells other than 9 per row, it may be desirable for each row of cells 110a, 110b, 120a in the outer stent 100 to include a multiple (e.g., an integer or multiple of an integer) of that different number. However, in yet other embodiments, such a correspondence between the number of cells in each row of the inner stent and the number of cells in the rows of the outer stent 100 is not necessary.

[0016] The connector between the atrial disk 110 and the ventricular disk 120 may be utilized as an anchor point for coupling the inner stent to the outer stent 100. For example, in FIG. 2, since there are three double clips 130, a total of three or six connection points may be utilized to couple the inner stent to the outer stent 100.

[0017] As shown in FIG. 2, there is no axially positioned metal stent structure between the ventricular disk 120 and the atrial disk 110 in the circumferential direction between adjacent double clips 130 in the circumferential direction. The pseudo-ring of the atrioventricular valve can be aligned with this gap 140 (and the double clip 130) as a whole when the artificial valve is implanted. This large gap 140 reduces the contact between the outer stent 100 and the native valve annulus, particularly reducing the contact between metal and tissue in these regions. Preferably, when implanted, the gap 140 is aligned with the base of the septal cusp SL to reduce or eliminate contact with the AV node (when implanted in the tricuspid valve), thereby minimizing or eliminating the potential for conduction disturbances. The same or similar positioning can be used when implanting an artificial valve into the native mitral valve annulus to avoid conduction disturbances. In some patients, a pacemaker may already be implanted in the heart, or it may be desirable to implant a pacemaker even if the conduction system has been less affected. The conduction gap 140 of the outer stent 100 can be further useful in avoiding interference with pacemaker leads near the artificial heart valve in such situations.

[0018] Once implanted, the outer stent 100 of FIG. 2 can provide adequate fixation even though there is a void 140 within the outer stent. For example, to provide good engagement with native tissue, the outflow end of the atrial disc 110 can "bite into" the native annulus upon deployment, and the inflow end of the ventricular disc 120 can "bite into" the native leaflet. For example, the outflow apex of the second row 110b of atrial cells and the inflow apex of the first row 120a of ventricular cells can engage native tissue. It should be understood that the expansion force of the outer stent 100 may also provide a certain amount of fixation within the native valve. Since the prosthetic valves described herein are intended for transcatheter implantation, these prosthetic valves are not typically sutured to the native annulus and thus need to maintain adequate fixation without the sutures or similar fixation mechanisms commonly used in surgical valve implantation. The connector between the atrial disc 110 and the ventricular disc 120 (e.g., the three double clips 130 shown in FIG. 2) will also push against the native annulus to assist with fixation. Although not shown, the outer stent 100 shown in FIG. 2 may include a skirt or cuff (e.g., a synthetic fiber such as PET or PTFE) to provide a seal between the outer stent 100 and the native annulus. The skirt or cuff may extend across the entire outer stent 100, including the space 140 where there is no metal structure. The presence of the skirt or cuff in this region is not expected to cause significant conduction disturbances even when aligned with the AV node, at least because the material is generally a soft non-metallic material.

[0019] Also, although not shown in FIG. 2, other fixation mechanisms can be provided to help maintain the engagement of the prosthetic heart valve within the native annulus after deployment. For example, pins, hooks, loops, paddles, teeth, etc. can be provided on the outer stent 100, and these features can engage native tissue to provide additional fixation.

[0020] Depending on the situation, the region 140 of the outer stent 100 without metal can cause potential problems when loading the artificial heart valve into the catheter for delivery or when deploying the artificial heart valve from the catheter. This discontinuity in the metal structure can cause the ventricular disk 120 to tend to "follow" the inversion during deployment (since it is the first part released from the catheter during transseptal delivery) or when loading the catheter for insertion into the patient. The inflow apex of the ventricular cell 120a can also cause the ventricular disk 120 to tend to bite into the delivery catheter or not be loaded smoothly into the delivery catheter when loading the artificial heart valve into the delivery catheter. For example, when the artificial heart valve is folded and drawn into the catheter (e.g., through a funnel), the inflow apex of the ventricular stent cell 120a tends to catch or be prone to biting into the structure of the loading funnel and / or the catheter during loading. To minimize the possibility of one or more of the above problems occurring, an additional fixation structure may be provided to couple the atrial intervertebral plate 110 to the ventricular intervertebral plate 120. For example, one or more sutures can be provided to couple the inflow apex of one or more ventricular cells 120a to the outflow apex of one or more atrial cells in the second row 110b. Such fixation structures can extend in a longitudinal or diagonal direction and any number can be provided. Such fixation structures tend to allow for smoother deployment and loading of the artificial heart valve despite the absence of metal in the region 140 between the ventricular disk 120 and the atrial disk 110. However, as described above, these fixation structures are preferably soft and / or non-metallic so as not to cause conduction disorders that may occur when the metal structure is pushed into the AV node or its native ring. Further, it should be understood that when these fixation structures are provided, they are preferably provided only at locations where the stent cells are "free floating" rather than, for example, in the region where the double clip 130 is provided.

[0021] FIG. 3 is a side perspective view of the outer stent 200 of the artificial atrioventricular valve according to another aspect of the present disclosure. Since the outer stent 200 of FIG. 3 is identical to the outer stent 100 of FIG. 2 in most respects, only the differences will be described for the sake of brevity. The reference numerals of the stent 200 used in FIG. 3 refer to similar or identical components within the stent 100 and are incremented by 100 (e.g., atrial rows 210a, 210b correspond to atrial rows 110a, 110b, respectively). The outer stent 100 of FIG. 2 is shown with three double clips 130 that couple the atrial disk 110 to the ventricular disk 120, while the outer stent 200 of FIG. 3 is shown with a similar double clip 230 having additional teeth 230c between the double clips or posts 230a, 230b. These additional teeth 230c can provide additional fixation by pushing against and / or engaging native tissue for fixation when deploying the outer stent 200 within the native valve annulus. Also shown in FIG. 3 are openings 230d in the clip / post 230 (e.g., near the base of the teeth 230c) that can be utilized to couple a connecting member, and as shown in other figures below, the other end of the connecting member is attached to the inner stent.

[0022] FIG. 4 shows the outer stent of FIG. 3 with annotations indicating the relative positions of the structures of the native tricuspid valve, including the anterior leaflet AL, septal leaflet SL, and posterior leaflet PL, after implantation. As shown, in one implantation state, the clip / post 230 is generally aligned with the native commissure, and one of the conduction gaps 240 is aligned with the base of the septal leaflet SL where the AV node is expected to be located. In other words, the force F of the outer stent 200 pushing against the native valve annulus is mostly concentrated on the clip / post 230, and the force F is hardly or not directly applied to the base of the septal valve leaflet SL, minimizing or eliminating the potential for conduction disturbances.

[0023] FIG. 5 shows a perspective view of the outer frame 300 according to a further aspect of the present disclosure. FIG. 6 shows a partial side view of the outer stent 300 of FIG. 5. FIG. 7 shows an enlarged view of the ventricular disk 320 of the outer stent 300 of FIG. 5. The outer stent 300 of FIGS. 5-7 is substantially similar to that shown in FIG. 2, but there are some differences. For the sake of brevity, only the differences will be described here. The reference numbers of the outer stent 300 used in FIGS. 5-7, which refer to similar or identical components within the stent 100, are increased by only 200 (e.g., the atrial disk 310 and the ventricular disk 320 correspond to the atrial disk 110 and the ventricular disk 120, respectively). One difference is that instead of the atrial disk 110 including two rows of cells 110a, 110b and the ventricular disk 120 including one row of cells 120a, the outer stent 300 of FIGS. 5-7 includes one row of cells 310a in the atrial disk and two rows of cells 320a, 320b in the ventricular disk. As best shown in FIGS. 6-7, the ventricular disk 320 may include an outward flare 322 at the outflow end of the ventricular disk 320, particularly at the outflow end of the outflow row of cells 320b. This outward flare 322 may help to better engage tissue on the ventricular side of the valve annulus, such as native leaflet tissue. By including two rows of cells 320a, 320b in the ventricular disk 320, additional surface area can be provided for securing or fixing the outer stent 300 within the native valve annulus. As best shown in FIG. 6, the posts 330a, 330b that couple the atrial disk 310 to the ventricular disk 320 may have a "C" or "U" shape in the expanded state, and the "C" or "U" shape is configured to receive a portion of the native valve annulus therein to firmly fix the artificial heart valve within the native valve annulus. In other words, the posts 330a, 330b can define a diameter that is smaller than the diameters of both the atrial disk and the ventricular disk in the expanded state of the outer frame 300 (and the expanded state of the artificial heart valve incorporating the outer frame 300).

[0024] FIG. 8 is a developed view of an internal frame or stent 400 according to one aspect of the present disclosure, cut longitudinally and laid flat on a table. In the expanded or deployed state, the inner stent 400 is generally cylindrical and can be positioned radially inward of an outer stent (e.g., outer stents 100, 200, 300 or other outer stents). Similar to the outer stent, the inner stent 400 can be formed from a foldable and expandable material such as a shape memory metal including nitinol. In the illustrated embodiment, the inner stent 400 includes two rows of cells in a generally diamond shape including an upper inflow row 410 and a lower outflow row 420, with nine cells in each row. However, as described above, the inner stent 400 may include more or fewer cells in each row 410, 420, and in some embodiments, may include more or fewer rows of cells. A plurality of connectors 430 may be provided on the inner stent 400. In the illustrated embodiment, three connectors 430 are provided in every third cell of the inflow row 410, but more or fewer connectors 430 may be provided. Preferably, the number of connectors 430 is the same as the number of posts or other connection mechanisms that couple the atrial disk of the outer stent to the ventricular disk of the outer stent. In the expanded state of the inner stent 400, each connector 430 extends radially outward and can be coupled to the outer stent at an outer stent post. In the illustrated embodiment, each connector 430 includes an opening 430d near its end, and each post of the outer stent may include a corresponding opening (e.g., opening 230d of the double clip 230 of outer stent 200) for coupling the inner stent connector 430 to the outer stent post through the opening using a rivet, suture, or other fastener. However, it should be understood that other fixing methods may be appropriate in some cases. In the illustrated embodiment of the inner stent 400, the connector 430 is formed of the same material as the inner stent 400 and may be integral with the inner stent 400. The connector 430 can be formed, for example, by laser cutting a nitinol tube to create the inner stent 400 shown in FIG. 8.The inner stent may include a commissure attachment mechanism 440 shown as a generally rectangular or square stent mechanism at the outflow ends of every third cell of the ventricular row 420. The commissure attachment features (「CAF」) 440 may include an opening and may be used to couple two adjacent bioprosthetic valve leaflets (e.g., via sutures) to the inner stent 400 at the CAF 440. Since the prosthetic heart valve incorporating the inner stent 400 of FIG. 8 includes three prosthetic (e.g., bioprosthetic or synthetic) valve leaflets, three CAFs 440 are shown in FIG. 8. Some or all of the ventricular cells 420 without CAF 440 may include a stent extension 450 that extends radially outwardly upon expansion and attaches to the ventricular disk of the outer stent to stabilize the ventricular disk of the outer stent during implantation of the prosthetic heart valve. Instead of coupling to the outer frame by making the stent extension 450 of the inner frame 400 longer, it can engage native anatomical structures such as native valve leaflets or chordae tendineae to further assist in fixing the prosthetic heart valve in place. In other embodiments, the outer stent may alternatively or additionally include a stent extension similar to that shown for the inner stent of FIG. 8.

[0025] FIG. 9 shows a top view of the outer stent 300 of FIG. 5 coupled to an inner stent 500 similar to that shown in FIG. 8. The only difference between the inner stent 500 and the inner stent 400 is that the inner stent 500 omits the stent extension 450 that is part of the inner stent 400. In particular, the three connectors 530 of the inner stent 500 extend outwardly from the inner stent 500 and couple to the respective posts 330a or 330b of each double clip 330. However, in other embodiments, the three connectors 530 of the inner stent 500 can separate, branch, or split near their ends such that each of the three connectors 530 of the inner stent 500 is attached to each of the posts 330a, 330b of each double clip 330. In this particular embodiment, the inner stent 500 and the outer stent 300 have rotational symmetry, which is at least partially enabled by including nine cells in each column of the inner frame 500 and a multiple of nine (27 in this embodiment) cells in each column of the outer frame 300. FIG. 10 shows the same configuration as FIG. 9 with certain additional features. In particular, FIG. 10 shows that the post 330a or 330b of each clip 330 of the outer stent 300 (when only one post is used) can function as an attachment site 335 for the inner stent connector 530. FIG. 10 also shows that, as described above, a skirt or cuff and / or suture material 350 may be provided between the atrial disk 310 and the ventricular disk 320 of the outer frame 300 spanning the metal-free region 340 between the atrial disk 310 and the ventricular disk 320. Also, FIG. 10 shows only a single void region 340 covered by the skirt and / or cuff and / or suture material, but it should be understood that all of the void region 340 may be covered by the skirt and / or cuff and / or suture material. Embodiments herein are generally disclosed and / or shown with columns of cells having nine cells, or an integer multiple of nine cells, but it should be understood that other numbers (and integer multiples) may also be appropriate.For example, particularly when including a set of three artificial valve leaflets with an inner stent (e.g., 400 or 500) mounted therein, the inner stent preferably includes a total number of cells that is a multiple of three (e.g., 3, 6, 9, 12, 15, 18, 21, etc.). In such an embodiment, it may also be preferable for the outer stent to have a row of cells having a number of cells that is a multiple of three, particularly a multiple of the number of cells in the row of the inner stent.

[0026] FIG. 11 shows a top view of an outer stent 600 similar to the outer stent 300 of FIG. 5. The atrial disk 610 includes a row of cells 610a, and the ventricular disk 620 includes two rows of cells having the same configuration as the outer stent 300, but has a double clip 630 that is substantially similar or identical to the double clip 230 of the outer stent 200. FIG. 11 shows the outer stent 600 coupled to the inner stent 500. As can be seen from the figure, the three inner stent connectors 530 extend radially outward to couple to the clips or posts 630 of the outer stent 600.

[0027] FIG. 12 is another top view showing that the inner stent 800 can include more than three connectors 830. In FIG. 12, the inner stent 800 is substantially similar or identical to the inner stent 500 of FIG. 8, except that a total of nine connectors 830 are provided to couple the inner stent 800 to the outer stent 700. The outer stent 700 may be substantially similar to the other outer stents described herein, except for the main exception that there are additional connection points 730 considering the additional connectors 830. The additional connection points 730 can be defined by or can include a continuous row of cells between the atrial disk and the ventricular disk. In other words, instead of having a large gap or void between the atrial disk and the ventricular disk, the outer stent 700 may have a complete or substantially complete circumferential row of cells extending between the ends of the outer stent.

[0028] The connectors 430, 530, 830 illustrated and described in connection with FIGS. 8-12 may all have substantially similar purposes. As described above, the connectors 430, 530, 830 can enable the inner frame to substantially maintain a cylindrical shape even when the outer frame is distorted (e.g., as a result of forces applied to the outer stent by the native valve ring during normal operation), so that the valve tip of the prosthesis can maintain a desirable shape and good attachment of the valve tip of the bioprosthesis is possible. They can serve to mechanically separate the generally cylindrical inner frame from the outer frame.

[0029] FIG. 13 is a highly schematic view showing an outer stent similar to the stents of FIGS. 2-3 disposed within the native tricuspid valve. This figure may also apply to the outer stent of FIG. 5. As shown in FIG. 13, the three posts / clips that couple the atrial disk to the ventricular disk are configured to be disposed at clip position L, where a major outward force F is applied from the outer stent to the valve annulus VA. On the other hand, the metal-free space between the posts does not exert a large force on the valve annulus because there is no metal structure of the outer stent in that region. One of these regions is preferably aligned with the conduction system CS, which includes the atrioventricular node AVN and / or the His bundle (not individually labeled in FIG. 13).

[0030] FIG. 14 is a very schematic cross-sectional view of the heart showing an outer stent similar to those of FIGS. 2-3 disposed within the native tricuspid valve TV. This figure may also apply to the outer stent of FIG. 5. As shown in FIG. 14, with the post / clip 130 (or 230, 330) spanning two disks, the ventricular disk 120 (or 220, 320) assists in fixing the tricuspid valve TV on the ventricular side, and the atrial disk 110 (or 210, 310) assists in positioning and / or fixing the tricuspid valve TV on the atrial side. In an outer frame (such as that shown in FIG. 5) with more rows of cells in the ventricular disk than in the atrial disk, the ventricular-side landing zone may be larger than the atrial side.

[0031] FIG. 15 is a very schematic cross-sectional view of the heart. As shown in the figure, any of the outer stents described herein may include a ventricular disk section that can at least partially function to engage the chordae tendineae CT of the tricuspid (or mitral) valve to push the chordae tendineae CT in the outer direction D and strengthen the fixation within the native valve annulus.

[0032] During the process of delivering a heart valve replacement and repair device, particularly a foldable and expandable artificial heart valve, it is usually convenient to be able to partially or fully recapture the device from the delivery catheter after initially partially or fully deploying the device from the catheter. For example, if the initial deployment of the artificial heart valve results in a non - desirable or sub - optimal position of the artificial heart valve relative to the malfunctioning heart valve, it may be desirable to pull the artificial heart valve back into the delivery catheter and attempt a second deployment of the artificial heart valve to achieve a more desirable position relative to the malfunctioning heart valve, or to abort the procedure and completely remove the artificial heart valve from the patient. When attempting to recapture an expandable artificial heart valve into the delivery catheter or another recapture device, various difficulties may be encountered. For example, the force required to fold a partially or fully expanded artificial heart valve to a diameter small enough to fit within the catheter can be relatively large. If the artificial heart valve includes a double - stent configuration, such as any of the artificial heart valves described herein where an inner stent is connected to an outer stent, the force can be even larger. Further, a relatively flexible and relatively long intravascular delivery catheter can be more difficult to handle such recapture forces compared to a shorter and more rigid transapical catheter. Additionally, if the artificial heart valve includes a double - flange or hourglass - shaped frame, recapturing a partially or fully deployed artificial heart valve can be more difficult compared to a frame having a generally continuous taper from a large diameter to a small diameter. Embodiments that can solve or mitigate some or all of these problems are described in more detail below, and these solutions can be implemented for any of the artificial heart valves described above, as well as for other specific designs of artificial heart valves not described above.

[0033] The artificial heart valve 1000 is shown in FIGS. 16 and 17. The artificial heart valve 1000 may include an outer frame 1100 and an inner frame 1200. Since the inner frame 1200 may be substantially similar or identical to the inner frame 500 or 800, it will not be described in further detail here. The outer frame 1100 may be substantially the same as the outer frame 700. In other words, the outer frame 1100 does not include a significant gap or void between the atrial disk 1110 and the ventricular disk (not individually labeled), rather, the outer frame 1100 may define a complete or substantially complete row of cells, which may be substantially diamond-shaped cells extending between the atrial disk and the ventricular disk. The outer frame 1100 does not include large gaps adjusted to avoid conduction disorders, but the rail system described below may be applicable to various other frame designs, including designs similar or identical to the outer frames 100, 200, 300, or 600. And, as with the other embodiments described herein, some parts of the artificial heart valve 1000, such as the artificial valve leaflets attached within the inner frame 1200 and the seal skirts of the cuffs provided on the inner and / or outer surfaces of the outer frame 1100 and / or the inner frame 1200, are omitted from the figures for clarity.

[0034] As shown in FIGS. 16 and 17, the outer frame 1100 may include one or more rails 1170 in addition to the general diamond-shaped cell structure of the outer frame 1100. In the illustrated embodiment, a total of nine rails 1170 are shown, and these rails are arranged substantially equidistantly around the outer frame 1100. In particular, each rail 1170 is shown to be positioned (circumferentially) between a pair of adjacent connectors 1230 of the inner frame 1200. However, the number and configuration of the rails 1170 shown in FIGS. 16 and 17 are merely exemplary. For example, the outer frame 1100 may include more or fewer than nine rails 1170. In some embodiments, the number of rails 1170 may be equal to the number of connectors 1230, but in other examples, the number of rails 1170 may be different from the number of connectors 1230. Further, although it is desirable for the rails 1170 to be arranged substantially equidistantly around the outer frame 1100, other relative arrangements may be appropriate. Further, each rail 1170 is shown to be positioned at approximately the midpoint in the circumferential direction between a pair of adjacent connectors 1230, but other relative positionings, including radial alignment between the connectors 1230 and the rails 1170, may be appropriate.

[0035] In some embodiments, the rail 1170 is formed of the same material as the outer frame 1100, such as a shape memory metal such as a nickel-titanium alloy containing nitinol. Each rail 1170 is formed separately from the outer frame 1100 and may be attached to the inside or outside of the outer frame via any suitable mechanism such as a fastener (e.g., a suture) or an adhesive. In other embodiments, each rail 1170 may be integrally formed with the outer frame 1100, for example, by laser cutting the cells of the outer frame 1100 and the rail 1170 from a single tube such as a nitinol tube. Regardless of whether the rail 1170 is formed separately from or integrally with the outer frame 1100, each rail 1170 has an axial extent that is substantially parallel to the central longitudinal axis of the artificial heart valve 1000. In other words, when the artificial heart valve 1000 is folded, the rail 1170 is substantially parallel to the central longitudinal axis of the artificial heart valve 1000. When the artificial heart valve expands, the rail 1170 can follow the contour from the inflow to the outflow of the outer frame 1100, but preferably, the rail 1170 does not have a large contour in the circumferential direction of the outer frame 1100.

[0036] As shown in FIGS. 15-16, the connector 1180 may be provided at the end of each post or rail 1170. For example, each rail 1170 may include a loop or similar structure at the end of the atrial disk 1110 on the side that is generally first folded during the retrieval procedure. However, in embodiments where the ventricular disk is first folded during the retrieval procedure, the connector 1180 may be disposed at the end of the rail 1170 on the ventricular disk side. In some embodiments, connectors 1180 may be provided at each end of the rail 1170 to allow for the selectivity of which end of the artificial heart valve 1000 is first folded during the retrieval procedure. The connector 1180 is shown as a loop or ring integrally formed with the rail 1170, but in other embodiments, the connector 1180 may take other shapes suitable for connection to the control element 1300, and in other embodiments, the connector 1180 may be formed on the outer stent 1100 adjacent to the rail 1170.

[0037] In use, one or more control elements 1300 may be coupled to the rail 1170 via the connector 1180. For example, the control element 1300 may be a flexible element such as a wire, cord, suture, etc. In some embodiments, a single control element 1300 may be coupled to each rail 1170. In other embodiments, a single control element 1300 may be coupled to two or more rails 1170 or all of the rails 1170, for example, by looping through the connector 1180. The control element 1300 may extend proximally through a catheter device 1400 that is a delivery device used for the initial deployment of the artificial heart valve 1000, or through a separate retrieval catheter specifically designed for retrieval and / or repositioning procedures. In some embodiments, the catheter device 1400 may include a funnel-shaped member 1410 at the end of the catheter 1400, and the funnel 1410 tapers from a tip that meets the distal end of the main portion of the catheter 1400 to the rear end.

[0038] In one exemplary use, a delivery catheter (which may be the same as or different from catheter 1400) is used to deliver the artificial heart valve 1000 to the native tricuspid or mitral valve annulus, for example, via the femoral vein, while the artificial heart valve 1000 is folded within the delivery catheter. The ventricular end of the artificial heart valve 1000 can be deployed by first pushing the artificial heart valve 1000 distally out of the delivery catheter or by pulling the delivery catheter proximally relative to the artificial heart valve 1000. Once the artificial heart valve 1000 exits the delivery catheter, it begins to self-expand to be positioned on the ventricular side of the native valve annulus. At some point after the deployment process has begun, the operator may determine that it is desirable to reposition the artificial heart valve 1000 or to completely remove the artificial heart valve 1000 from the patient. If such a determination is made, the operator can pull the control element 1300 in the proximal direction P relative to the catheter 1400 and / or push the catheter 1400 distally relative to the control element 1300. It should be understood that either option is feasible, but it may be more preferable to push the catheter 1400 distally while the control element 1300 remains in a substantially stationary position relative to the anatomical structure, compared to pulling the control element 1300 in the proximal direction while the catheter 1400 remains in a substantially static position relative to the anatomical structure. Pushing the catheter 1400 distally for retrieval may be preferred based on the possibility that the ventricular disk is already fully expanded and pulling the ventricular disk against the native valve annulus may damage the valve annulus. As described above, this retrieval process can be performed using the original delivery catheter or, for example, via another retrieval catheter that can be delivered over or through the original delivery catheter. This operation causes the artificial heart valve 1000 to be pulled back into the catheter 1400 and the expanded portion to be refolded and returned into the catheter 1400. When the artificial heart valve 1000 is drawn into and folded within the catheter device 1400, the rails 1170 assist in the distribution of the recoiling force and enable the artificial heart valve 1000 to be folded more easily and uniformly within the catheter device 1400.

[0039] As described above, in some embodiments using the rail 1170, the rail 1170 can be integrally formed with the outer frame 1100, for example, by laser cutting the cells of the outer frame 1100 and the rail 1170 from a single tube such as a Nitinol tube. FIG. 18A shows an example of a mechanism for integrally forming the rail 1170a with the outer frame 1100a. As shown in FIG. 18A, the outer frame 1100a may include one or more rows of substantially diamond-shaped cells 1190a in which each row is "free floating" in the sense that the upper and lower vertices of one column of cells 1190a are not directly connected to the upper or lower vertices of adjacent columns or cells 1190a. Each rail 1170a connects the side vertices of one cell within a column to the side vertices of an adjacent cell within the same column of cells 1190a. FIG. 18A shows three rows of cells 1190a with a rail 1170a every two cells (e.g., two cells 1190a between each pair of circumferentially adjacent rails 1170a), but other numbers of rows of cells 1190a may be used, and different spacings of the rails 1170a (e.g., one cell 1190a between each pair of circumferentially adjacent rails 1170a, or three or more cells 1190a between each pair of circumferentially adjacent rails 1170a) may be appropriate. Finally, it should be understood that FIG. 18A shows only a representative portion of the outer frame 1170a.

[0040] FIG. 18B is conceptually similar to the outer frame 1170a, but instead of having columns of "free floating" cells 1190a, the outer frame 1170b includes columns of struts 1190b each having a "zigzag" pattern, with each pair of adjacent struts forming a common "V" shape and the vertices of the "V" facing in alternating directions. The outer frame 1100b is shown with five columns of zigzag struts and four struts between each pair of adjacent rails 1170b, but it should be understood that the frame may include more or fewer than five columns of zigzag struts, and each column may include more or fewer than four struts between each pair of circumferentially adjacent rails 1170b. Also, although not shown, the rails 1170a and 1170b may include connectors similar to those described above, including alternatives described below.

[0041] Similar to frame 1100a, frame 1100b may be formed as a single piece member (e.g., cut by laser from a single tube of nitinol). Since the rails are substantially straight and have no shortening function, the rails 1170a and 1170b do not shorten as the frame expands. However, the "free floating" cells 1190a may individually shorten during expansion, but since adjacent columns are not directly connected to each other, this shortening does not interfere with the rails 1170a. Similarly, each column of zigzag struts 1190b may shorten as the frame 1100b expands, but this shortening does not interfere with the rails 1170b.

[0042] In the above-described embodiments including rails for retrieval and / or repositioning, it should be understood that retrieval may be performed before the atrial section of the outer frame is completely released from the delivery catheter. However, in some embodiments, retrieval may be performed after the artificial heart valve has been completely released (e.g., fully expanded) from the delivery catheter. After the artificial heart valve has been completely released, it may be more difficult to retrieve the artificial heart valve, but the force required for retrieval is greater than when the artificial heart valve is only partially expanded, so it is still one of the options. For example, applying a retrieval force to the distal end of the catheter can facilitate such retrieval. Also, while it may generally be more difficult to perform such retrieval when the delivery catheter is deflected in multiple planes, after partially folding the artificial valve, it can be moved to be positioned within the right atrium, where the catheter can be straightened to more easily complete the retrieval.

[0043] Further, the rails 1170 are generally shown with a single connector 1180 at each end, although other connector options may be suitable. For example, each rail may include a plurality of connectors or eyelets along its length (e.g., where a row of "free floating" cells 1190a are disposed, or at any junction where a row of zigzag struts 1190b are disposed). In this embodiment, a wire, suture, or other control element runs circumferentially through the aligned eyelets of the rails, such that when the control element applies tension, it helps to force circumferential folding of the frame.

[0044] Although the invention has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. Thus, it should be understood that many modifications can be made to the exemplary embodiments and other configurations can be devised without departing from the spirit and scope of the invention as defined by the appended claims. In addition, the technical ideas that can be grasped from the above embodiments will be described below in terms of their aspects. [Aspect 1] A foldable and expandable artificial atrioventricular valve, an outer stent having an atrial disk, a ventricular disk, and a plurality of posts connecting the atrial disk to the ventricular disk, an inner stent, a plurality of connectors extending between the inner stent and the outer stent and connecting the inner stent to the outer stent, a plurality of artificial valve leaflets attached within the inner stent, comprising, the outer stent having no metal in a space extending circumferentially between adjacent ones of the plurality of posts, the space extending about one-third of the circumference of the outer stent, artificial atrioventricular valve. [Aspect 2] The artificial atrioventricular valve according to Aspect 1, wherein the atrial disk has two circumferential cell rows and the ventricular disk has one circumferential cell row. [Aspect 3] The artificial atrioventricular valve according to Aspect 1, wherein the atrial disk has one circumferential cell row and the ventricular disk has two circumferential cell rows. [Aspect 4] The artificial atrioventricular valve according to Aspect 1, wherein the plurality of posts includes three posts, and each of the three posts includes two struts extending from the atrial disk to the ventricular disk. [Aspect 5] The artificial atrioventricular valve according to Aspect 4, wherein each of the two struts of each of the three posts has a first end coupled to a first vertex of each cell of the atrial disk and a second end coupled to a second vertex of each cell of the ventricular disk. [Aspect 6] The artificial atrioventricular valve according to Aspect 5, wherein each of the three posts includes teeth between the two struts. [Aspect 7] The artificial atrioventricular valve according to Aspect 6, further comprising an opening formed in one of the two struts or in each of the teeth of each of the three posts, and each of the plurality of connectors being coupled to the outer stent through a corresponding one of the openings. [Aspect 8] The artificial atrioventricular valve according to Aspect 1, wherein in the expanded state of the artificial atrioventricular valve, the diameter of the outer stent at the plurality of posts is smaller than the diameter of the outer stent at the atrial disk and the ventricular disk. [Aspect 9] The artificial atrioventricular valve according to Aspect 1, wherein the inner stent includes a circumferential row of first cells having a total number, the outer stent includes a circumferential row of second cells having a total number, and the total number of the second cells is an integer multiple of the total number of the first cells. [Aspect 10] The artificial atrioventricular valve according to Aspect 9, wherein the total number of the second cells is 27, and the total number of the first cells is 9. [Aspect 11] A method for replacing a native atrioventricular valve of the heart, the method comprising: delivering the artificial atrioventricular valve to the native atrioventricular valve while the artificial atrioventricular valve is folded within a delivery catheter, the artificial atrioventricular valve including an outer stent, an inner stent coupled to the outer stent, and a plurality of artificial valve leaflets mounted within the inner stent; deploying the artificial atrioventricular valve from the delivery catheter such that the artificial atrioventricular valve is self-expanding; comprising enabling the artificial atrioventricular valve to be self-expanding includes disposing an atrial disk of the outer stent on the atrial side of the native atrioventricular valve and disposing a ventricular disk of the outer stent on the ventricular side of the native atrioventricular valve; after the artificial atrioventricular valve self-expands within the native atrioventricular valve, aligning a gap in the outer stent between a pair of adjacent posts connecting the atrial disk to the ventricular disk with the cardiac conduction system. Method. [Aspect 12] An artificial atrioventricular valve system, comprising: an outer stent having an atrial portion and a ventricular portion; an inner stent; a plurality of connectors extending between the inner stent and the outer stent and coupling the inner stent to the outer stent; a plurality of artificial valve leaflets mounted within the inner stent; comprising the outer stent includes one or more circumferential cell rows and a plurality of rails extending axially from the atrial portion to the ventricular portion. Artificial atrioventricular valve system. [Aspect 13] The artificial atrioventricular valve system according to Aspect 12, wherein the cells of the one or more circumferential cell rows of the outer stent are diamond-shaped. [Aspect 14] The artificial atrioventricular valve system according to Aspect 12, wherein each of the plurality of rails includes a connector at its end. [Aspect 15] The artificial atrioventricular valve system according to Aspect 14, further comprising at least one flexible control member coupled to the connector of each of the plurality of rails. [Aspect 16] The artificial atrioventricular valve system according to aspect 15, wherein the flexible control member is a suture thread. [Aspect 17] The artificial atrioventricular valve system according to aspect 15, wherein in the retrieved state of the artificial atrioventricular valve system, the outer stent is at least partially deployed from the delivery catheter, and the flexible control member extends proximally through the interior of the delivery catheter. [Aspect 18] A method of recapturing an artificial atrioventricular valve, the method comprising: delivering the artificial atrioventricular valve to the native atrioventricular valve while the artificial atrioventricular valve is folded within a delivery catheter, the artificial atrioventricular valve including an outer stent having an atrial portion and a ventricular portion, an inner stent coupled to the outer stent, and a plurality of artificial valve leaflets mounted within the inner stent, the outer stent including one or more circumferential cell rows and a plurality of rails extending axially from the atrial portion to the ventricular portion; deploying the artificial atrioventricular valve from the delivery catheter such that the artificial atrioventricular valve is at least partially self-expanding; after at least partially self-expanding the artificial atrioventricular valve, retrieving the artificial atrioventricular valve into a retrieval catheter; comprising: retrieving the artificial atrioventricular valve includes folding the artificial atrioventricular valve into the retrieval catheter by manipulating at least one flexible control member coupled to a plurality of connectors, each of the plurality of connectors being coupled to a corresponding one of the plurality of rails; method. [Aspect 19] The method according to aspect 18, wherein the retrieval catheter is the delivery catheter. [Aspect 20] The retrieval catheter is a separate device from the delivery catheter, and after deploying the artificial atrioventricular valve from the delivery catheter and before retrieving the artificial atrioventricular valve, the retrieval catheter advances along or through the delivery catheter, according to the method of aspect 19.

Claims

**Claim 1** A foldable and expandable artificial tricuspid valve, an outer stent having an atrial disk, a ventricular disk, and a plurality of posts coupling the atrial disk to the ventricular disk, an inner stent, a plurality of connectors extending between the inner stent and the outer stent and coupling the inner stent to the outer stent, a plurality of artificial valve leaflets mounted within the inner stent, comprising, wherein the outer stent has no metal in a circumferentially extending space between adjacent ones of the plurality of posts, the space extending about one-third of the circumference of the outer stent, and in a transplanted state of the artificial tricuspid valve, being aligned with a base of a septal leaflet of a native tricuspid valve so as to minimize contact between metal and tissue between the outer stent and the atrioventricular node, the artificial tricuspid valve. **Claim 2** The artificial tricuspid valve according to claim 1, wherein the atrial disk has two circumferential cell rows and the ventricular disk has one circumferential cell row. **Claim 3** The artificial tricuspid valve according to claim 1, wherein the atrial disk has one circumferential cell row and the ventricular disk has two circumferential cell rows. **Claim 4** The artificial tricuspid valve according to claim 1, wherein the plurality of posts includes three posts, and each of the three posts includes two struts extending from the atrial disk to the ventricular disk. **Claim 5** The artificial tricuspid valve according to claim 4, wherein each of the two struts of each of the three posts has a first end coupled to a first apex of each cell of the atrial disk and a second end coupled to a second apex of each cell of the ventricular disk. **Claim 6** The artificial tricuspid valve according to claim 5, wherein each of the three posts includes teeth between the two struts. **Claim 7** The artificial tricuspid valve according to claim 6, further comprising an opening formed in one of the two struts or in the teeth of each of the three posts, and each of the plurality of connectors being coupled to the outer stent through a corresponding one of the openings. **Claim 8** The artificial tricuspid valve according to claim 1, wherein in an expanded state of the artificial tricuspid valve, a diameter of the outer stent at the plurality of posts is smaller than a diameter of the outer stent at the atrial disk and the ventricular disk. **Claim 9** The inner stent includes a circumferential row of first cells having a total number, and the outer stent includes a circumferential row of second cells having a total number, wherein the total number of the second cells is an integer multiple of the total number of the first cells. The artificial tricuspid valve according to claim 1.

10. The artificial tricuspid valve according to claim 9, wherein the total number of the second cells is 27, and the total number of the first cells is 9.

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