A mitral valve replacement prosthesis and its outer cage

Abstract

The application discloses a mitral valve replacement prosthesis and an outer support thereof, and belongs to the field of heart valve replacement prostheses. The outer support comprises, from top to bottom, an atrial fixation section located in an atrium, a mitral valve annulus blocking section and a mitral valve replacement prosthesis inner support connecting section located in a ventricle. The upper edge of the atrial fixation section and the lower edge of the inner support connecting section are circular or quasi-circular. The cross section of the mitral valve annulus blocking section is a wavy D-shaped structure. The connecting rods in the inner support connecting section comprise at least one wavy connecting rod. At least two identical or two different mark points are arranged on the petal structure of the atrial fixation section. The wavy D-shaped structure and the wavy rectangular structure are arranged, so that the circumferential rotation and the up-and-down displacement are effectively prevented, and the service life of the prosthesis is improved. The elastic wavy connecting rod is arranged, so that the production and processing success rate is improved and the service life is prolonged. The mark points are increased, so that the prosthesis is more easily identified during surgery, and the surgery efficiency and success rate are improved.

Description

Technical Field

[0001] This invention relates to the field of heart valve replacement prostheses, and in particular to a mitral valve replacement prosthesis and its external stent. Background Technology

[0002] Valvular heart disease is a very serious condition affecting a large population and with a high mortality rate. Currently, there are no conservative treatments such as specific drugs; surgical treatment is the best solution, including surgical valve replacement or interventional procedures for valve repair or replacement. Among surgical treatments, interventional procedures have gained widespread acceptance from doctors and patients due to their advantages such as low surgical risk, minimally invasive nature, and good treatment outcomes.

[0003] Currently, well-known domestic and international medical device manufacturers, such as Medtronic, Abbott, Edwards, MicroPort, Venus Med, and PediaSure, have launched products for interventional valve replacement, all of which have achieved good therapeutic effects. Among them, Abbott's Tendyne product has attracted much attention due to its D-shaped anatomical design, double-layer stents (inner and outer layers), and the use of apical pads and tethers to fix the prosthesis. (See attached image) Figure 1 and 2 As shown, Figure 1 It is a combination of an external stent 1 and an internal stent 2 with a D-type anatomical design. The external stent 1 includes, from top to bottom, an atrial fixation segment A, a mitral valve annulus occlusion segment B, and a connection segment C with the internal stent. Figure 2 This is a diagram of the external stent in its unfolded state before final shaping. However, this D-shaped anatomical design has the following problems: First, because the occlusion section B of the external stent has straight edges on both sides, the stent can move up and down. Therefore, the stability of the stent relies heavily on the petal-shaped atrial fixation section A located within the atrium and the apical pad located at the apex of the heart. Second, although the stent has a D-shaped structure and provides some anti-rotation protection, the mitral valve annulus is relatively soft and its outer wall is smooth. Therefore, circumferential rotation is possible both during prosthesis installation and during use.

[0004] Furthermore, during interventional cardiac surgery, doctors cannot visually locate the prosthesis; a C-arm is required. Thus, the markers on the valve prosthesis are shown in the attached image. Figure 2The mark point o in the D-shaped structure is used to help the doctor to accurately and quickly find the valve prosthesis and accurately know the position of the high edge, the low edge, the straight edge and the round edge of the outer stent. In principle, as long as the mark point o is located at one position of the straight edge of the D-shaped structure, the accurate position of the valve prosthesis can be calculated. However, one mark point will make the doctor have to remember whether the mark point is located at the straight edge or the round edge, whether it is located at the left side or the right side, whether it is the left side or the right side that we see or the left side or the right side of the prosthesis itself, which is very easy to mix up. At the same time, one mark point will also bring some troubles in production. The accurate position of the mark point must be given, and a careless mistake will easily lead to processing errors and increase the scrap rate. Once such scrap is misused, it may lead to surgical failure and even death of the patient.

[0005] In addition, if the design is according to the unfolded form of the existing outer stent laser cutting diagram, it will inevitably cause the mutual pulling deformation of each cell of the outer stent, and also cause a certain height change, and even cause a fracture. If the design is not according to the unfolded diagram, but the connecting rods of the inner stent connecting section are designed to be long and short, when the inner and outer stents are contracted after assembly, the inner and outer stents will be pulled due to the length difference, and individual positions will be deformed due to excessive stress, leading to fracture.

[0006] Therefore, the existing mitral valve replacement prosthesis still has disadvantages in structure, method and use, and needs to be further improved. How to create a new mitral valve replacement prosthesis and its outer stent, which can effectively overcome the rotation of the stent in the circumferential direction, the up-down displacement, and improve the operation recognition by increasing the mark point position, reduce the production difficulty, and improve the production success rate, has become the current industry's goal for improvement. SUMMARY

[0007] The technical problem to be solved by the present application is to provide an outer stent of a mitral valve replacement prosthesis, which can effectively overcome the rotation of the stent in the circumferential direction, the up-down displacement, and improve the operation recognition by increasing the mark point position, reduce the production difficulty, and improve the production success rate, so as to overcome the shortcomings of the existing outer stent of the mitral valve replacement prosthesis.

[0008] To solve the above technical problems, the present application provides an outer stent of a mitral valve replacement prosthesis, which comprises, from top to bottom, an atrial fixation section located in the atrium, a mitral valve annulus occlusion section, and an inner stent connecting section of a mitral valve replacement prosthesis located in the ventricle. The upper edge of the atrial fixation section and the lower edge of the inner stent connecting section are circular or circular-like. The cross section of the mitral valve annulus occlusion section is in a D-shaped structure. The cross section of the mitral valve annulus occlusion section is in a wavy D-shaped structure.

[0009] Further improvement, the height difference between the wave peak and the wave trough of the wavy D-shaped structure is in the range of 1mm-8mm, wherein the overhang of the wave trough is greater than or equal to 1mm, and the overhang of the wave peak is less than or equal to 10mm.

[0010] Further improvement, the longitudinal section of the mitral annulus occlusion section is a rectangular structure.

[0011] Further improvement, the height of the rectangular structure is 5mm-30mm.

[0012] Further improvement, the longitudinal section of the mitral annulus occlusion section is a rectangular structure with wavy sides.

[0013] Further improvement, the height of the wavy rectangular structure is 5mm-30mm, the height difference between the wave peak and the wave trough of the wavy side is in the range of 1mm-8mm, and the overhang of the wave trough of the three-dimensional solid formed by the wavy side and the wavy D-shaped structure is greater than or equal to 1mm, and the overhang of the wave peak is less than or equal to 10mm.

[0014] Further improvement, the connecting rods connected to the inner stent in the inner stent connecting section include at least one wavy connecting rod.

[0015] Further improvement, the connecting rods connected to the inner stent in the inner stent connecting section include at least two connecting rods with different lengths, wherein the connecting rod located below the D-shaped straight edge of the mitral annulus occlusion section is the shortest connecting rod, the shortest connecting rod is a straight connecting rod or a wavy connecting rod, and the remaining connecting rods are wavy connecting rods.

[0016] Further improvement, the wavy connecting rods have different stretching lengths.

[0017] Further improvement, the atrial fixation section includes a plurality of petal structures arranged along the circumference, and at least two identical marker points are arranged on the petal structures, and the at least two identical marker points are respectively and symmetrically arranged on the petal structures above the two ends of the D-shaped straight edge of the mitral annulus occlusion section or above the petal structures of the middle section of the D-shaped arc-shaped edge of the mitral annulus occlusion section.

[0018] Further improvement, the atrial fixation section includes a plurality of petal structures arranged along the circumference, and at least two different marker points are arranged on the petal structures, wherein at least one marker point is arranged on the petal structure above the D-shaped straight edge of the mitral annulus occlusion section, and at least another marker point is arranged on the petal structure above the middle section of the D-shaped arc-shaped edge of the mitral annulus occlusion section.

[0019] As another improvement of the present application, the present application further provides an outer support of a mitral valve replacement prosthesis, which comprises, from top to bottom, an atrial fixation segment located in an atrium, a mitral valve annulus blocking segment, and an inner support connecting segment of the mitral valve replacement prosthesis located in a ventricle, the upper edge of the atrial fixation segment and the lower edge of the inner support connecting segment are circular or quasi-circular, the cross section of the mitral valve annulus blocking segment is a D-shaped structure, and the longitudinal section of the mitral valve annulus blocking segment is a wavy rectangular structure.

[0020] Further improvement, the height difference of the wave crest and trough of the wavy rectangular structure ranges from 1mm to 8mm, wherein the single-side interference of the trough is greater than or equal to 1mm, and the single-side interference of the wave crest is less than or equal to 10mm.

[0021] Further improvement, the connecting rods connected with the inner support in the inner support connecting segment comprise at least one wavy connecting rod.

[0022] Further improvement, the connecting rods connected with the inner support in the inner support connecting segment comprise at least two connecting rods with different lengths, wherein the connecting rod located below the straight side of the D-shaped structure of the mitral valve annulus blocking segment is the shortest connecting rod, the shortest connecting rod adopts a straight connecting rod or a wavy connecting rod, and the remaining connecting rods all adopt wavy connecting rods.

[0023] Further improvement, the stretching lengths of the wavy connecting rods are different.

[0024] Further improvement, the atrial fixation segment comprises a plurality of petal structures arranged along the circumference, and at least two identical mark points are arranged on the petal structures, wherein the at least two identical mark points are symmetrically arranged on the petal structures above the two ends of the straight side of the D-shaped structure of the mitral valve annulus blocking segment, or are symmetrically arranged on the petal structures above the middle segment of the arc-shaped side of the D-shaped structure of the mitral valve annulus blocking segment.

[0025] Further improvement, the atrial fixation segment comprises a plurality of petal structures arranged along the circumference, and at least two different mark points are arranged on the petal structures, wherein at least one mark point is arranged on the petal structures above the straight side of the D-shaped structure of the mitral valve annulus blocking segment, and at least another mark point is arranged on the petal structures above the middle segment of the arc-shaped side of the D-shaped structure of the mitral valve annulus blocking segment.

[0026] As another improvement of the present application, the present application further provides a mitral valve replacement prosthesis comprising the above-mentioned outer support of the mitral valve replacement prosthesis.

[0027] After adopting such design, the present application at least has the following advantages:

[0028] 1. The outer support of the mitral valve replacement prosthesis of the present application increases the resistance of the prosthesis to rotate circumferentially by setting the D-shaped structure into a wavy D-shaped structure, further prevents the occurrence of paravalvular leakage, and improves the use effect of the prosthesis. Further, through the setting of the wavy rectangular structure, the valve prosthesis can be better fixed, the up-down positioning effect of the valve prosthesis is better, thereby reducing the dependence of the outer support on the upper petals of the prosthesis and the lower apex pad of the prosthesis, thereby greatly improving the service life of the prosthesis.

[0029] 2. Further, through the setting of the elastic wavy connecting rod, stress distribution can be better and more reasonable, the risk of fracture during processing is reduced, and the risk of fracture during later use of the valve prosthesis is also reduced.

[0030] 3. Further, at least two or at least two marker points are set on the petals of the atrial fixation section, which are respectively distributed on both sides of the straight edge of the D-shaped structure and the middle of the arc-shaped edge, so that they are more easily identified during surgery, improve the efficiency and success rate of surgery, are also beneficial to production and processing, reduce production difficulty, and improve production success rate. BRIEF DESCRIPTION OF DRAWINGS

[0031] The above is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the present application is further described in detail below in combination with the drawings and specific embodiments.

[0032] Figure 1 is a structure diagram of the connection between the outer support and the inner support of the mitral valve replacement prosthesis of the existing manufacturer.

[0033] Figure 2 is a structure diagram of the unfolded structure of the outer support of the mitral valve replacement prosthesis of the existing manufacturer after laser cutting.

[0034] Figure 3 is a front view structure diagram of the outer support of the mitral valve replacement prosthesis of the present application.

[0035] Figure 4 is a perspective structure diagram of the outer support of the mitral valve replacement prosthesis of the present application.

[0036] Figure 5 is a top view structure diagram of the outer support of the mitral valve replacement prosthesis of the present application.

[0037] Figure 6 is Figure 5 a structure diagram of the cross section of the mitral valve annulus occlusion section in the middle.

[0038] Figure 7 is Figure 4 a structure diagram of the longitudinal section of the mitral valve annulus occlusion section in the middle.

[0039] Figure 8is the unfolded structure diagram of the outer stent of the mitral valve replacement prosthesis after laser cutting Figure 1 .

[0040] Figure 9 is the unfolded structure diagram of the outer stent of the mitral valve replacement prosthesis after laser cutting Figure 2 . DETAILED DESCRIPTION

[0041] The existing heart valve replacement prosthesis includes an outer stent, an inner stent, a tether and an apex pad. Among them, the outer stent and the inner stent are connected and assembled in a plug-in, welded or bundled manner, the inner stent and the tether are connected and assembled in a buckling + suturing manner, and the tether and the apex pad are connected and assembled in a needle threading manner. The present application is a multi-faceted improvement on the structure of the outer stent of the existing mitral valve replacement prosthesis, which not only facilitates identification and operation during surgery, but also effectively prevents the circumferential rotation or upward and downward displacement of the prosthesis, prevents the occurrence of paravalvular leakage, prolongs the service life of the prosthesis, improves the success rate of the prosthesis during expansion and molding, reduces the production difficulty, and has good market prospects. The specific embodiments are as follows.

[0042] Referring to the accompanying Figures 3 to 6 , the outer stent of the mitral valve replacement prosthesis of the embodiment includes, from top to bottom, an atrial fixation segment A located in the atrium, a mitral valve annulus occlusion segment B and a mitral valve replacement prosthesis inner stent connecting segment C located in the ventricle. Among them, the upper edge of the atrial fixation segment A and the lower edge of the inner stent connecting segment C are circular or circular-like, and the cross section of the mitral valve annulus occlusion segment B is a wave-shaped D-shaped structure, as shown in the accompanying Figure 6 .

[0043] The wave-shaped D-shaped structure is the most important part of the outer stent design, which presents a D-shaped structure consistent with the anatomical morphology of the mitral valve annulus, which can maximize the prevention of paravalvular leakage. And because of the D-shaped structure instead of circular or circular-like, it can prevent the circumferential rotation of the prosthesis. The D-shaped structure of the present embodiment is set to a wave-shaped structure, which can further effectively prevent the circumferential rotation of the prosthesis and ensure the service life of the prosthesis.

[0044] Specifically, the height difference of the wave crest and wave trough of the wave-shaped D-shaped structure is in the range of 1-8mm, wherein the single-sided interference of the wave trough, i.e. the minimum pressure fitting amount is 1mm, and the single-sided interference of the wave crest is 10mm at most.

[0045] Since the mitral annulus of human body is not a planar structure, but a three-dimensional structure similar to a saddle, in order to better prevent paravalvular leakage, the occlusion segment B of the outer stent must also have a rectangular structure with a certain height. In order to further prevent the up-and-down displacement of the prosthesis, the longitudinal section of the mitral annulus occlusion segment B in the embodiment adopts a rectangular structure with wavy sides, which can firmly fix the prosthesis on the mitral annulus, thereby reducing the dependence of the prosthesis on the atrial fixation segment and the apical pad, achieving the technical effect that even if the apical pad does not work during use, the tether is loose, the valve prosthesis can also be fixed in place for a long time by means of the wavy structure of the outer stent, thereby greatly improving the service life of the prosthesis.

[0046] The height of the wavy rectangular structure in the embodiment is 5-30 mm, preferably 15 mm, the height difference of the wave crest and wave trough of the wavy side is 1-8 mm, and in the three-dimensional space formed by the wavy side and the wavy D-shaped structure, the overlap of the wave trough is at least 1 mm, and the overlap of the wave crest is at most 10 mm.

[0047] Of course, the wavy D-shaped structure and the wavy rectangular structure in the embodiment can exist alone on the outer stent, respectively playing the roles of preventing the circumferential rotation and the up-and-down displacement of the outer stent.

[0048] Since the connecting segment C of the external stent needs to transition from the D-shape at the bottom of the occlusion segment B to the circular shape connecting with the internal stent, if all the connecting rods are straight and of equal length, then when the external stent is directly expanded and shaped after laser cutting, it will inevitably cause mutual tensile deformation of each unit cell of the valve annulus occlusion segment B and the atrial fixation segment C, resulting in a certain height change, and even breakage. If the connecting rods are set to have varying lengths, then when the internal and external stents are assembled and contracted, the different heights of the internal and external stents will cause tension, and some positions may deform due to excessive stress, leading to breakage. To solve this problem, in this embodiment, the connecting rod 13 connecting the internal stent to the internal stent in the connecting segment C includes at least one wavy connecting rod, preferably including at least two types of connecting rods 13 with different lengths. Among them, the connecting rod located below the straight edge of the D-shape of the mitral valve annulus occlusion segment B is the shortest connecting rod. The shortest connecting rod can be a straight connecting rod or a wavy connecting rod, and the remaining connecting rods are all wavy connecting rods. Furthermore, the tensile amount of the wavy connecting rods can be the same or different. This wavy connecting rod retains its supporting and connecting functions while utilizing its elasticity to ensure that during heat treatment expansion and shaping, the unit cells of the valve annulus occlusion segment B and the atrial fixation segment A are not stretched, thus ensuring better stress distribution and reducing the risk of breakage during processing and shaping. This also reduces the risk of breakage during later valve implant use. Furthermore, during valve surgery, when the entire valve is retracted into the sheath, the elasticity of the connecting rod prevents the inner and outer stents from pulling on each other, ensuring smooth implant release and safe surgical completion. This effectively solves the technical problems of outer stent shaping and connection with the inner stent. Moreover, the wavy connecting rod has a uniform height when not straightened, which is beneficial for manufacturing.

[0049] In this embodiment, the inner support connecting section C includes four connecting rods 13 of different lengths, as shown in the attached figure. Figure 8 and 9 As shown, this includes connecting rods 131, 132, 133, and 134. Depending on their position, the straightened lengths of connecting rods 131, 132, 133, and 134 differ, with the basic relationship being: L131 < L134 ≤ L133 ≤ L132. Connecting rod 131, located below the straight edge of the D-shaped section B of the mitral valve annulus occlusion segment, is the shortest connecting rod. Therefore, the shortest connecting rod 131 can be a straight connecting rod, as shown in the attached diagram. Figure 8 As shown, the connecting rod can also be wavy, as shown in the attached figure. Figure 9 As shown.

[0050] A more preferred embodiment is that the atrial fixation segment A includes multiple petal structures arranged circumferentially. These petal structures unfold outward in a petal shape and adhere to the atrial wall, thereby preventing the valve prosthesis from shifting into the ventricle. At least two identical marking points are provided on each petal structure. These marking points are symmetrically arranged on the petal structures above the two ends of the D-shaped straight edge of the mitral valve annulus occlusion segment B, or symmetrically arranged on the petal structures above the middle section of the D-shaped arc edge of the mitral valve annulus occlusion segment B.

[0051] Alternatively, at least two different marking points may be provided on the petal structure, wherein at least one marking point is provided on the petal structure above the straight edge of the D-shaped mitral valve annulus occlusion segment B, and at least another marking point is provided on the petal structure above the middle section of the arc-shaped edge of the D-shaped mitral valve annulus occlusion segment B.

[0052] In this embodiment, the atrial fixation segment A includes 12 petal structures of varying heights arranged circumferentially. Two of these petal structures correspond to the upper edge of the D-shaped straight edge of the mitral valve annulus occlusion segment B, and one petal structure corresponds to each end of the D-shaped straight edge. The remaining petal structures are symmetrically arranged above the D-shaped arcuate edge. (See attached diagram.) Figures 3 to 5 As shown in Figures 8 and 9, this embodiment includes four distinct marker points: two semi-circular marker points 11 corresponding to the petal structure at both ends of the straight edge of the D-shape, and two inverted trapezoidal marker points 12 corresponding to the petal structure in the middle of the curved edge of the D-shape. Thus, during cardiac interventional surgery, the surgeon, using a C-arm, can accurately and quickly locate the valve prosthesis by observing marker points 11 and 12, and simultaneously pinpoint the location of the prosthesis's high edge, low edge, straight edge of the D-shape, and curved edge, greatly facilitating the surgery. For example, if the surgeon sees two marker points 11 appearing first during surgery, their shape and relatively large distance between them indicate that they represent the two ends of the straight edge; if the surgeon sees two marker points 12 appearing later, their shape and close distance indicate that they are on the curved edge of the D-shape. Furthermore, during production, the location of the marker points eliminates defects, significantly improving the yield rate.

[0053] Of course, the marker 11 can also be a triangle, inverted trapezoid, rhombus, circle, or other shape, as long as it can be distinguished from the shape of marker 12. Similarly, the marker 12 can also be a triangle, semicircle, rhombus, circle, or other shape, as long as it can be distinguished from the shape of marker 11. Furthermore, the number of petal structures can be any number between 10 and 20, determined according to actual usage needs and the selected processing pipe material. The number of markers 11 and 12 can also be set according to the number of petal structures.

[0054] The outer support in the embodiment is made of a memory alloy of nickel-titanium alloy or nitinol alloy material.

[0055] The outer support of the mitral valve replacement prosthesis of the application increases the resistance of the prosthesis to rotate circumferentially by setting the D-shaped structure in a wavy D-shaped structure, further prevents the occurrence of paravalvular leakage, and improves the use effect of the prosthesis. Further, through the setting of the wavy rectangular structure, the valve prosthesis can be better fixed, the up-down positioning effect of the valve prosthesis is better, thereby reducing the dependence of the outer support on the upper petals of the prosthesis and the lower apical pad of the prosthesis, and greatly improving the service life of the prosthesis. Further, through the setting of the elastic wavy connecting rod, stress distribution can be better and more reasonable, the risk of fracture during processing and molding is reduced, and the risk of fracture during use of the valve prosthesis is also reduced. Further, at least two same or at least two different marker points are arranged on the petals of the atrial fixation section, which are distributed on both sides of the straight edge of the D-shaped structure or in the middle of the arc-shaped edge, so that they are more easily identified during surgery, improve the efficiency and success rate of surgery, are also beneficial to production and processing, reduce the production difficulty, and improve the production success rate.

[0056] In the description of the application, it should be noted that the terms "upper", "lower", "front", "back", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the application.

[0057] In the description of the application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0058] The above is only a preferred embodiment of the application, and does not limit the application in any form, and those skilled in the art can make some simple modifications, equivalent changes or modifications by using the technical content disclosed above, which falls within the protection scope of the application.

Claims

1. An outer frame of a mitral valve replacement prosthesis, the outer frame comprising, from top to bottom, an atrial fixation segment located in the atrium, a mitral valve annulus occlusion segment, and a mitral valve replacement prosthesis inner frame connection segment located in the ventricle, the upper edge of the atrial fixation segment and the lower edge of the inner frame connection segment are circular or quasi-circular, the cross section of the mitral valve annulus occlusion segment is a D-shaped structure, characterized in that, The cross-section of the mitral valve annulus occlusion section is a wavy D-shaped structure; The connecting rods connected to the internal stent in the internal stent connection section include at least two types of connecting rods with different lengths. Among them, the connecting rod located below the straight edge of the D-shaped mitral valve annulus occlusion section is the shortest connecting rod. The shortest connecting rod is either a straight connecting rod or a wavy connecting rod, and the remaining connecting rods are all wavy connecting rods. The atrial fixation segment includes multiple petal structures arranged along the circumference. Each petal structure has at least two identical marking points. The at least two identical marking points are symmetrically arranged on the petal structures above the two ends of the D-shaped straight edge of the mitral valve annulus occlusion segment, or symmetrically arranged on the petal structures above the middle section of the D-shaped arc edge of the mitral valve annulus occlusion segment.

2. The external stent of the mitral valve replacement prosthesis according to claim 1, characterized in that, The wave-shaped D-structure has a peak-to-trough height difference ranging from 1mm to 8mm, wherein the interference on one side of the trough is greater than or equal to 1mm, and the interference on one side of the peak is less than or equal to 10mm.

3. The external stent of the mitral valve replacement prosthesis according to claim 1, characterized in that, The longitudinal section of the mitral valve annulus occlusion segment is a rectangular structure.

4. The external stent of the mitral valve replacement prosthesis according to claim 3, characterized in that, The height of the rectangular structure is 5mm-30mm.

5. The external stent of the mitral valve replacement prosthesis according to claim 1, characterized in that, The longitudinal section of the mitral valve annulus occlusion segment is a rectangular structure with wavy sides.

6. The external stent of the mitral valve replacement prosthesis according to claim 5, characterized in that, The height of the wavy rectangular structure is 5mm-30mm, the height difference between the peaks and troughs of its wavy side is 1mm-8mm, and the interference of the troughs of the three-dimensional structure formed by the wavy side and the wavy D-shaped structure is greater than or equal to 1mm, and the interference of the peaks of the three-dimensional structure is less than or equal to 10mm.

7. The external stent of the mitral valve replacement prosthesis according to claim 1, characterized in that, The wavy connecting rods have different extension lengths.

8. The external stent of the mitral valve replacement prosthesis according to any one of claims 1 to 6, characterized in that, The atrial fixation segment includes multiple petal structures arranged along the circumference. At least two different marking points are provided on the petal structures. At least one marking point is provided on the petal structure above the straight edge of the D-shaped mitral valve annulus occlusion segment, and at least another marking point is provided on the petal structure above the middle section of the arc-shaped edge of the D-shaped mitral valve annulus occlusion segment.

9. An external stent for a mitral valve replacement prosthesis, the external stent comprising, from top to bottom, an atrial fixation segment located within the atrium, a mitral valve annulus occlusion segment, and an internal stent connection segment within the mitral valve replacement prosthesis located within the ventricle, wherein the upper edge of the atrial fixation segment and the lower edge of the internal stent connection segment are both circular or near-circular, and the cross-section of the mitral valve annulus occlusion segment is a D-shaped structure, characterized in that... The longitudinal section of the mitral valve annulus occlusion section is a rectangular structure with wavy sides; The connecting rods connected to the internal stent in the internal stent connection section include at least two types of connecting rods with different lengths. Among them, the connecting rod located below the straight edge of the D-shaped mitral valve annulus occlusion section is the shortest connecting rod. The shortest connecting rod is either a straight connecting rod or a wavy connecting rod, and the remaining connecting rods are all wavy connecting rods. The atrial fixation segment includes multiple petal structures arranged along the circumference. Each petal structure has at least two identical marking points. The at least two identical marking points are symmetrically arranged on the petal structures above the two ends of the D-shaped straight edge of the mitral valve annulus occlusion segment, or symmetrically arranged on the petal structures above the middle section of the D-shaped arc edge of the mitral valve annulus occlusion segment.

10. The external stent of the mitral valve replacement prosthesis according to claim 9, characterized in that, The height difference between the crests and troughs of the wavy rectangular structure ranges from 1mm to 8mm, wherein the interference on one side of the trough is greater than or equal to 1mm, and the interference on one side of the crest is less than or equal to 10mm.

11. The external stent of the mitral valve replacement prosthesis according to claim 10, characterized in that, The wavy connecting rods have different extension lengths.

12. The external stent of the mitral valve replacement prosthesis according to claim 9 or 10, characterized in that, The atrial fixation segment includes multiple petal structures arranged along the circumference. At least two different marking points are provided on the petal structures. At least one marking point is provided on the petal structure above the straight edge of the D-shaped mitral valve annulus occlusion segment, and at least another marking point is provided on the petal structure above the middle section of the arc-shaped edge of the D-shaped mitral valve annulus occlusion segment.

13. A mitral valve replacement prosthesis, characterized in that, The external stent of the mitral valve replacement prosthesis as described in any one of claims 1 to 12.

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