Sealing component and artificial heart valve

Abstract

The utility model provides a sealing component and an artificial heart valve. The artificial heart valve comprises a support, an artificial valve leaflet and the sealing component. The sealing component is used for being connected with the support and used for wrapping at least part of the outer contour of the support. At least partial area of the sealing component comprises a base layer and an extension layer, and the extension layer is fixed to the outer surface of the base layer and surrounds the whole perimeter of the base layer. The extension layer can deform so as to be used for filling a gap between the base layer and the target tissue. The sealing component of the artificial heart valve can fill the gap between the target tissue and the base layer and is tightly attached to the target tissue, so that perivalvular leakage is effectively prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, in particular to a sealing component and an artificial heart valve. Background Art

[0002] The heart contains four chambers. The left atrium and left ventricle are located on the left side of the heart, and the right atrium and right ventricle are located on the right side of the heart. The ventricular inflow tract is formed between the atrium and the ventricle, the left ventricular outflow tract is formed by the left ventricle and the aorta, and the right ventricle and the pulmonary artery form the right ventricular outflow tract. There are valves with "one-way valve" functions at the positions of the left ventricular inflow tract and the right ventricular inflow tract to ensure the normal flow of blood in the heart chamber. When there is a problem with the valve, the heart's hemodynamics changes, the heart function is abnormal, and it becomes valvular heart disease.

[0003] With the development of social economy and the aging of population, the incidence of valvular heart disease has increased significantly. Studies have shown that the incidence of valvular heart disease in the elderly population over 75 years old is as high as 13.3%. At present, traditional surgical treatment is still the first choice for patients with severe valvular disease, but for the elderly, patients with multiple organ diseases, patients with a history of open-chest surgery and patients with poor heart function, traditional surgical treatment has high risks and mortality, and some patients do not even have the opportunity for surgery. Transcatheter mitral valve replacement repair has the advantages of no need for open-chest surgery, less trauma, and faster patient recovery, and has received widespread attention from experts and scholars.

[0004] In recent years, the valve field has developed rapidly, but there are still some problems that need to be solved, such as paravalvular leakage. Paravalvular leakage is mainly caused by the poor adhesion between the artificial heart valve and the native tissue, resulting in blood leakage from the gap between the valve and the tissue. Utility Model Content

[0005] In order to solve the technical problems existing in the prior art, the purpose of the present utility model is to provide a sealing component and an artificial heart valve, wherein the sealing component of the artificial heart valve can fill the gap between the base layer and the target tissue and fit tightly with the target tissue to effectively prevent the occurrence of paravalvular leakage.

[0006] To achieve the above-mentioned purpose, the utility model provides a sealing component, which is used to be connected to a stent and to cover at least a portion of the outer contour of the stent; at least a portion of the sealing component includes a base layer and an extension layer, and the extension layer is fixed to the outer surface of the base layer and surrounds the entire circumference of the base layer; the extension layer can be deformed to fill the gap between the base layer and the target tissue.

[0007] Optionally, one end of the extension layer is connected to the base layer, and the other end of the extension layer is configured to extend along the outflow end of the bracket toward the inflow end of the bracket.

[0008] Optionally, the extension layer includes a plurality of trichomes; the trichomes have a fixed end and a free end, the fixed end of the trichomes is connected to the base layer, and the free ends of the plurality of trichomes can be interlaced with each other to form a mesh structure.

[0009] Optionally, the trichomes are made of poly(lactide-glycolide) material.

[0010] Optionally, when preparing the trichomes, the molar ratio of glycolide in the poly(lactide-glycolide) is 50% to 85%.

[0011] Optionally, the base layer is a woven structure, and the base layer is made of a material selected from the group consisting of PET, PTFE, nylon, natural fibers, and synthetic fibers.

[0012] Optionally, the sealing member includes a first section, a second section and a third section connected in sequence along the axial direction of the stent, the first section covers the inflow part of the stent, the second section covers the transition part of the stent; the third section covers the outflow part of the stent; the second section includes the base layer and the extension layer.

[0013] Optionally, the elongation of the prepared material of the first section is greater than 10%.

[0014] Optionally, the permeability of the material used to prepare the third section is less than 500 ml / cm2*min, and the third section is prepared using a material selected from the group consisting of polyester fabric, PTFE, ePTFE and biological tissue.

[0015] Optionally, the first section is folded at the inflow end of the bracket and abuts against the inner circumference of the bracket, and / or the third section is folded at the outflow end of the bracket and abuts against the inner circumference of the bracket.

[0016] To achieve the above objectives, the utility model also provides an artificial heart valve, comprising a stent, an artificial valve leaflet and any one of the sealing components described above, wherein the artificial valve leaflet is fixed inside the stent, and the sealing component is fixed on the stent and is used to cover at least part of the outer contour of the stent.

[0017] The utility model provides a sealing component and an artificial heart valve, wherein an extension layer of the sealing component is arranged along the outer wall circumferentially of a base layer and extends outwardly in a direction away from the base layer. The extension layer can fill the gap between the target tissue and the stent to block the gap, thereby slowing down or even avoiding the occurrence of paravalvular leakage, thereby achieving the purpose of preventing and treating paravalvular leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the unfolded structure of the sealing component in a preferred embodiment of the utility model;

[0019] Figure 2 This is a schematic diagram of the bending structure of the sealing member in a preferred embodiment of the utility model, wherein direction a represents the flow direction of blood, and direction b represents the extension direction of the trichomes;

[0020] Figure 3 This is a schematic diagram of a usage scenario of an artificial heart valve in a preferred embodiment of the utility model.

[0021] In the figure: sealing member 1; base layer 11; extension layer 12; trichomes 121; first section 13; second section 14; third section 15; stent 2; inflow portion 21; transition portion 22; outflow portion 23; inflow end 24; outflow end 25; artificial valve leaflet 3; native tissue 10. DETAILED DESCRIPTION

[0022] The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the utility model will become clearer. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0023] The orientation or position relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0024] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be directly connected or connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In the description of the present invention, the meaning of "multiple" is at least two, such as two or three or more, etc.

[0025] The present invention is described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the absence of conflict, the following embodiments and features in the embodiments may complement or be combined with each other.

[0026] like Figure 1 to Figure 3 As shown, a preferred embodiment of the present invention provides a sealing member 1, which is used to be connected to a bracket 2 and to cover at least a portion of the outer contour of the bracket 2. Preferably, the sealing member 1 covers the entire outer contour of the bracket 2.

[0027] Reference Figure 1 to Figure 3 As shown, at least part of the sealing member 1 includes a base layer 11 and an extension layer 12. The extension layer 12 is fixed to the outer surface of the base layer 11 and surrounds the entire perimeter of the base layer 11, that is, the extension layer 12 is implanted on the base layer 11 and covers at least part of the outer contour of the base layer 11 over the entire perimeter of the base layer 11. The extension layer 12 can be deformed to fill the gap between the base layer 11 and the target tissue (i.e., the native tissue 10).

[0028] Reference Figure 3 As shown, a preferred embodiment of the utility model also provides an artificial heart valve, including a sealing component 1, a stent 2 and an artificial valve leaflet 3, wherein the artificial valve leaflet 3 is fixed inside the stent 2, and the sealing component 1 is fixed on the stent 2 and is used to cover at least part of the outer contour of the stent 2.

[0029] Since the native tissue 10 (ref. Figure 1 ) has an irregular shape. After the stent 2 is implanted and expanded, a gap may form between the outer wall of the stent 2 and part of the native tissue 10, and blood may flow back along the gap, thereby causing paravalvular leakage.

[0030] The present application provides a sealing component and an artificial heart valve, wherein the extension layer 12 of the sealing component 1 is arranged along the circumference of the outer wall of the base layer 11 and extends outward in a direction away from the base layer 11. The extension layer 12 can fill the gap between the target tissue and the stent 2 to block the gap, thereby slowing down or even avoiding the occurrence of paravalvular leakage, thereby achieving the purpose of preventing and treating paravalvular leakage.

[0031] Further, the stent 2 can provide several functions for the artificial heart valve, including being used as the main structure of the artificial heart valve, carrying the internal artificial valve leaflets 3, and being a connection structure (hanging ears or fixed ears) with the delivery system. The present application does not limit the structure of the stent 2. For example, the stent 2 can be prepared by weaving or by laser cutting. The present application does not limit the material of the stent 2. For example, the stent 1 can be made of materials such as nickel titanium, titanium alloy, cobalt chromium alloy, MP35n, 316 stainless steel, or a metal frame made of other biocompatible metals or a fixed metal tube cut by laser. Of course, it is not limited to this, and it can also be made of elastically or plastically deformable materials, such as balloon-expandable materials.

[0032] Furthermore, the artificial valve leaflet 3 can dynamically switch between two states, open and closed. In the closed state, the artificial valve leaflet 3 can be closed in a sealed abutment manner. In some embodiments, the artificial valve leaflet 3 can be selected from biological tissue materials, such as chemically stable tissue taken from the heart valve of an animal (such as a pig), or pericardial tissue taken from an animal, such as bovine pericardium, sheep pericardium, porcine pericardium or horse pericardium tissue, preferably bovine pericardium tissue. In other embodiments, the artificial valve leaflet 3 can also be made of small intestinal submucosal tissue. The utility model does not limit the material for preparing the artificial valve leaflet 3.

[0033] Preferably, the base layer 11 is a woven structure, for example, it can be prepared by weaving or knitting to form a woven structure. The base layer 11 is preferably made of a material selected from PET (polyethylene terephthalate), PTFE (polytetrafluoroethylene), nylon, natural fibers or synthetic fibers, that is, the yarn used in the base layer 11 can be made of materials such as biocompatible thermoplastic polymers, PET, PTFE or nylon.

[0034] Continue to refer to Figure 1 and Figure 2 The sealing member 1 includes a first section 13, a second section 14 and a third section 15 which are sequentially connected along the axial direction of the stent 2, and the stent 2 includes an inflow portion 21, a transition portion 22 and an outflow portion 23 which are sequentially connected along its own axial direction. The first section 13 covers the inflow portion 21 of the stent 2, the second section 14 covers the transition portion 22 of the stent 2, and the third section 15 covers the outflow portion 23 of the stent 2. That is, the first section 13, the second section 14 and the third section 15 correspond to the inflow portion 21, the transition portion 22 and the outflow portion 23 of the stent 2, respectively, and wrap the outer contours of the inflow portion 21, the transition portion 22 and the outflow portion 23, respectively. The second section 14 includes a base layer 11 and an extension layer 32 fixed on the base layer 11.

[0035] It should be noted that after the stent 2 is implanted and expanded, the first section 13 of the sealing member 1 is attached to the native valve ring of the heart, and the inflow portion 21 of the stent 2 expands and squeezes the surrounding native tissue 10 (refer to Figure 1 ) to anchor the stent 2 and prevent the stent 2 from falling from the atrium into the ventricle. The transition portion 22 of the stent 2 is used to carry the artificial valve leaflet 3, and the artificial valve leaflet 3 is fixed in the transition portion 22 of the stent 2. After the stent 2 is expanded, the transition portion 22 relies on the anchoring force of the stent 2 to abut against the native tissue 10 to play the role of anchoring and sealing.

[0036] Since the inflow portion 21 of the stent 2 needs to be well adapted to the morphology of the native tissue 10, the first section 13 of the sealing member 1 corresponding to the inflow portion 21 needs to have good elasticity, and the material used to prepare the first section 13 needs to have good tensile properties. In one example, the elongation of the material used to prepare the first section 13 is greater than 10%, and the first section 13 can be made of PET material and prepared by knitting. In this case, the first section 13 can be well matched with the soft inflow portion 21, thereby better adapting to the morphology of the native tissue 10.

[0037] In a preferred embodiment, the first section 13 is folded at the inflow end 24 of the stent 2 and abuts against the inner circumference of the stent 2 to prevent human tissue from being damaged by the sharp stent rod during the implantation of the stent 2 .

[0038] Furthermore, since blood is prone to backflow in the outflow portion 23 of the stent 2, the third section 15 of the sealing member 1 needs to be able to effectively prevent backflow. In a preferred case, the permeability of the material of the third section 15 is less than 500 ml / cm 2 *min, so that the blood penetration on the third section 15 can be reduced, thereby reducing the backflow of blood. The third section 15 is preferably made of a material selected from polyester fabric, PTFE, ePTFE and biological tissue, for example, it can be made of pericardial material, and is preferably made by knitting, weaving or braiding, so as to further enable the third section 15 to have the function of reducing blood penetration.

[0039] In an optional solution, the third section 15 is folded at the outflow end 25 of the stent 2 and abuts against the inner circumference of the stent 2 to prevent human tissue from being damaged by the sharp stent rod during the implantation of the stent 2.

[0040] Reference Figure 2 and Figure 3 As shown, in a preferred embodiment, the stent 2 has an inflow end 24 and an outflow end 25, and blood flows from the inflow end 24 of the stent 2 to the outflow end 25 of the stent 2. One end of the extension layer 12 is connected to the base layer 11, and the other end of the extension layer 12 is configured to extend along the outflow end 25 of the stent 2 toward the inflow end 24 of the stent 2.

[0041] The present application does not limit the connection method between the extension layer 12 and the base layer 11. The extension layer 12 can be connected and fixed to the outer surface of the base layer 11 preferably by braiding, knitting or weaving. During the preparation of the sealing member 1, the other end of the extension layer 12 away from the base layer 11 can be extended toward the inflow end 24 of the stent 2. When the extension layer 12 is in contact with the native tissue 10, since the inclination direction of the extension layer 12 is opposite to the flow direction of the blood, the blood can be better blocked, thereby improving the blocking effect of the sealing member 1.

[0042] Reference Figure 1 and Figure 2 As shown, in a preferred embodiment, the extension layer 12 includes a plurality of trichomes 121, and the trichomes 121 are preferably evenly arranged on the outer surface of the base layer 11. In this embodiment, the trichomes 121 cover all the outer surfaces of the base layer 11. In other embodiments, the trichomes 121 may only cover part of the outer surface of the base layer 31.

[0043] Continue to refer to Figure 1 to Figure 3 The trichome 121 has a fixed end and a free end (not numbered), the fixed end of the trichome 121 is connected to the base layer 11 (preferably, the fixed end of the trichome 121 and the base layer 11 can be woven together), and the free end extends outward. The free ends of the multiple trichomes 121 can be intertwined with each other to form a mesh structure (i.e., a grid shape).

[0044] In more detail, at least part of the free ends of the trichomes 221 are configured to extend along the outflow end 25 of the stent 2 toward the inflow end 24 of the stent 2, that is, the free ends of the trichomes 121 extend in the direction b (see Figure 2 ). When arranged in this way, although from a microscopic point of view, the inclination directions of the free ends of all the trichomes 121 are different, from a macroscopic point of view, for example, through weaving techniques, the trichomes 121 can be made to extend in the direction b as a whole. That is to say, when the trichomes 121 are prepared, a structure is formed in which the trichomes 121 extend in the direction b as a whole on the base layer 11.

[0045] When the trichomes 121 are affected by the outside world, the trichomes 121 can be deformed, thereby changing their extension direction (i.e., the tilt direction). For example, after the stent 2 is implanted in the human body and expanded, the stent 2 has a radial outward force to meet the anchoring of the artificial heart valve at the target position, and the trichomes 121 of the extension layer 12 are deformed by the force. For another example, the trichomes 121 can be deformed under the impact of blood flow after being attached to the native tissue 10. From a microscopic point of view, the deformation direction of the trichomes 121 is random, and the free ends of the trichomes 121 have different directions under the action of pressure and are intertwined with each other, and then interweave into a mesh structure in the gap. With such a configuration, the mesh structure can seal the gap to physically isolate the blood, greatly reduce the blood flow rate in the gap, and even prevent blood from flowing in the gap, thereby preventing the occurrence of paravalvular leakage.

[0046] In addition, due to the action of coagulation factors in the blood, after a period of time, the blood remaining in the reticular structure will coagulate, thereby closing the gap between the stent 2 and the native tissue 10. In addition, the trichomes 121 of the present application, after being interwoven to form a reticular structure, can also act as a medium for fibrosis formation, helping fibroblasts to grow into the blood clot, thereby promoting endothelialization in the gap, so as to achieve the purpose of stabilizing the stent 2 and the artificial valve leaflet 3.

[0047] To avoid paravalvular leakage, the trichomes 121 are preferably made of a material that can effectively prevent paravalvular leakage.

[0048] In a preferred embodiment, the trichomes 121 are made of poly(lactide-glycolide) (PLGA) material, because the poly(lactide-glycolide) material has the function of absorbing blood cells such as coagulation factors and platelets, and can promote blood coagulation in the interstitial position to further block the blood from passing through the interstitial position.

[0049] As a preferred embodiment, when preparing the trichomes 121, the molar ratio of glycolide in poly(lactide-glycolide) is 50% to 85%.

[0050] In more detail, the degradation time of the poly(glycol-lactide) material has multiple influencing factors, and therefore has multiple adjustment methods. In a specific example, the degradation time of the poly(glycol-lactide) can be changed by adjusting the molar ratio of glycolide and lactide during preparation. Specifically, as the molar ratio of glycolide in the copolymer increases, the degradation rate of the poly(glycol-lactide) increases. When preparing the trichome 121, when the molar ratio of glycolide in the poly(glycol-lactide) is 50%, that is, the molar ratio of glycolide to lactide is 1:1, the degradation time of the poly(glycol-lactide) is about 50 to 60 days; when the molar ratio of glycolide in the poly(glycol-lactide) is 85%, that is, the molar ratio of glycolide to lactide is 17:3, the degradation time of the poly(glycol-lactide) is about 150 to 160 days.

[0051] Since the completion time of the extension layer 12 from coagulation to fibroblast growth and then to fibrosis in the gap is generally within two weeks, in order to ensure that there is sufficient time for the artificial valve leaflet 3 to enter a stable state, that is, to ensure that the gap position has endothelialization before the trichomes 121 are completely degraded, the degradation time of the trichomes 121 is preferably within 50 to 150 minutes, so the molar ratio of glycolide in the preparation of poly(lactide-glycolide) is 50% to 85%. In this way, the sealing of the gap position will not be affected due to the too short degradation time of the trichomes 121.

[0052] Furthermore, the artificial heart valve further includes sutures (not shown), which are used to fix the first section 13, the third section 15, the base layer 11 and the artificial leaflet 3 of the sealing member 1 to the stent 2. Specifically, the sutures are used to connect the stent 2, the artificial leaflet 3 and the sealing member 1 as a whole and to connect them to each other. The materials used to make the sutures include, but are not limited to, PTFE, ePTFE or PE (polyethylene) materials.

[0053] In summary, the utility model provides a sealing component and an artificial heart valve, wherein the extension layer 12 of the sealing component 1 is arranged along the circumference of the outer wall of the base layer 11 and extends outward in a direction away from the base layer 11. The extension layer 12 can fill the gap between the target tissue and the stent 2 to block the gap, thereby slowing down or even avoiding the occurrence of paravalvular leakage, thereby achieving the purpose of preventing and treating paravalvular leakage.

[0054] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation to the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the protection scope of the utility model.

Claims

1. A sealing member, characterized in that: The sealing member is used to be connected to the stent and to cover at least a portion of the outer contour of the stent; at least a portion of the sealing member includes a base layer and an extension layer, the extension layer is fixed to the outer surface of the base layer and surrounds the entire circumference of the base layer; the extension layer can be deformed to fill the gap between the base layer and the target tissue.

2. The sealing member according to claim 1, wherein One end of the extension layer is connected to the base layer, and the other end of the extension layer is configured to extend along the outflow end of the bracket toward the inflow end of the bracket.

3. The sealing member according to claim 2, characterized in that The extension layer comprises a plurality of trichomes; the trichomes have a fixed end and a free end, the fixed end of the trichomes is connected to the base layer, and the free ends of the plurality of trichomes can be interlaced with each other to form a mesh structure.

4. The sealing member according to claim 3, wherein: The trichomes are made of poly(lactide-glycolide) material.

5. The sealing member according to claim 1, wherein: The base layer is a woven structure, and the base layer is made of a material selected from the group consisting of PET, PTFE, nylon, natural fibers, and synthetic fibers.

6. The sealing member according to any one of claims 1 to 5, characterized in that The sealing component includes a first section, a second section and a third section connected in sequence along the axial direction of the stent, the first section covers the inflow part of the stent, the second section covers the transition part of the stent; the third section covers the outflow part of the stent; the second section includes the base layer and the extension layer.

7. The sealing member according to claim 6, wherein: The elongation of the prepared material of the first section is greater than 10%.

8. The sealing member according to claim 6, wherein: The permeability of the material used to prepare the third section is less than 500 ml / cm2*min, and the third section is prepared using a material selected from the group consisting of polyester fabric, PTFE, ePTFE and biological tissue.

9. The sealing member according to claim 6, wherein: The first section is folded at the inflow end of the bracket and abuts against the inner circumference of the bracket, and / or the third section is folded at the outflow end of the bracket and abuts against the inner circumference of the bracket.

10. An artificial heart valve, characterized in that: It comprises a stent, an artificial valve leaflet and a sealing component as described in any one of claims 1 to 9, wherein the artificial valve leaflet is fixed inside the stent, and the sealing component is fixed on the stent and is used to cover at least part of the outer contour of the stent.

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