CN111973316B

CN111973316B - Tether for heart valve and heart valve

Info

Publication number: CN111973316B
Application number: CN201910425358.1A
Authority: CN
Inventors: 褚华磊; 姚斌; 刘香东
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Shenzhen Jianxin Medical Technology Co ltd
Priority date: 2019-05-21
Filing date: 2019-05-21
Publication date: 2023-10-20
Anticipated expiration: 2039-05-21
Also published as: CN111973316A; WO2020233598A1

Abstract

The present invention relates to a heart valve and a tether for the heart valve. The heart valve includes: a valve stent, the valve stent includes a main body stent and a skirt stent provided on the main body stent, the skirt stent extends outward along the radial direction of the main body stent; valve leaflets, the valve leaflets The leaves are arranged in the main body bracket; and the tether is connected to the main body bracket, and the tether is visible under X-rays. During the implantation process, the status of the tether is observed through X-ray. If the tether appears twisted or bent under X-ray, the tether can be tightened to make it straight to ensure the tension between the tether and the valve stent. Appropriate to ensure that the heart valve will not fit poorly under the impact of blood flow and reduce the probability of paravalvular leakage.

Description

Tether for heart valve and heart valve

Technical Field

The application relates to the field of medical equipment, in particular to a tether for a heart valve and the heart valve.

Background

This section provides merely background information related to the present disclosure and is not necessarily prior art.

As the population ages, older valve-related diseases become more prominent. These valve lesions not only endanger life safety, affect quality of life, but also bring heavy burden and pressure to the home and society. There are two common methods of treating heart valve disease: 1) Annuloplasty, i.e., repair of a damaged valve; 2) Valve replacement is performed with either an artificial mechanical valve or a biological valve. The valve replacement can generally adopt an interventional therapy method, has the advantages of small trauma, low operation risk and the like, and has wider market demands.

Referring to fig. 1, the heart valve 1 comprises a skirt holder 11, a leaflet holder 12, a leaflet (not shown) and a tether 13, the outer diameter of the skirt holder 11 being larger than the opening of the mitral valve MV, the skirt holder 11 being positioned on the left atrium side when the mitral valve prosthesis 1 is implanted in the heart such that the heart valve 1 as a whole "seats" on the tissue at the opening of the mitral valve and does not fall out of the left atrium side into the left ventricle, the leaflet holder 12 being positioned in the native mitral valve position, the tether 13 being attached to the distal end of the leaflet holder 12 and being fixed in position at the apex of the heart. However, when the heart valve 1 is fixed at the apex of the heart, due to the interaction between the tether 13 and the tissue, blood washout, knotting inside the connecting wire, etc., the strength sensing and the position of the heart valve under the X-ray cannot well determine whether the tether 13 is tensioned and the heart valve 1 is fixed.

Disclosure of Invention

The application aims to provide a tether for a heart valve and the heart valve.

A heart valve, comprising:

a valve holder comprising a body holder and a skirt holder disposed on the body holder, the skirt holder extending radially outwardly of the body holder;

a leaflet, the leaflet She She disposed within the body scaffold; and

And a tether coupled to the main body support, the tether being visible under X-rays.

A tether for a heart valve, comprising:

a core layer made of a polymer material doped with a developing material, an

The braiding layer wraps the core layer and is formed by braiding high polymer wires.

According to the heart valve, the tether is arranged to be visible under the X-ray, the state of the tether is observed through the DSA in the implantation process, if the tether is in a twisted or bent state under the X-ray, the tether can be tensioned to be in a straight line, the proper tension of the tether and the valve support is ensured, the poor fitting of the heart valve under the impact of blood flow is ensured, and the occurrence probability of paravalvular leakage is reduced. In addition, by arranging the tether to be visible under X-rays, it is also possible to determine whether paravalvular leakage occurs by observing the state of the tether during the follow-up.

Drawings

FIG. 1 is a schematic diagram of a prior art heart valve after implantation in a heart;

FIG. 2 is a schematic diagram of a heart valve according to an embodiment of the present application;

FIG. 3 is a schematic view of the heart valve of FIG. 2 from another perspective;

FIG. 4 is a schematic view of the heart valve of FIG. 2 after implantation in the heart;

FIG. 5 is an exploded view of the connector of the heart valve shown in FIG. 2;

FIG. 6 is a schematic view of the connector shown in FIG. 5 after being connected to a tether;

FIG. 7 is a schematic structural view of a tether according to another embodiment of the present application;

FIG. 8 is a schematic view of the structure of the tether shown in FIG. 7 after the developing wire is knotted;

FIG. 9 is a schematic view of the structure of the tether shown in FIG. 7 after tying;

FIG. 10 is a schematic structural view of a tether according to yet another embodiment of the present application;

FIG. 11 is a schematic view of the structure of the tether shown in FIG. 10 during braiding;

FIG. 12 is a test structure diagram of the tether and core shown in FIG. 10.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit or scope of the application, which is therefore not limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The present application is described with respect to a heart valve for replacing a mitral valve, and the concepts of the present application may also be applied to a prosthetic heart valve for replacing a tricuspid valve, a pulmonary valve, or an aortic valve. The heart valve tissue according to the present application is one or a combination of several kinds of heart tissue such as the annulus, the valve leaflet, the chordae tendineae, and the papillary muscle of the human body. In the delivery state, the heart valve is contracted in the delivery system, so that delivery is facilitated; in the deployed state, the heart valve is disengaged from the delivery system and secured in apposition with the heart tissue.

Referring to fig. 2, the heart valve 10 includes a valve holder 100, a tether 150, a flow blocking member 170 and a leaflet 190, the valve holder 100 includes a main body holder 110, a skirt holder 120 and a fixing member 130, the skirt holder 120 and the fixing member 130 are respectively disposed on the main body holder 110, the skirt holder 120 and the fixing member 130 are respectively used for fixing heart tissue in two opposite cavities in the heart, and the tether 150 is connected with the main body holder 110. In this embodiment, skirt stent 120 is adapted to anchor to the heart tissue on the left atrial side and anchor 130 is adapted to anchor to the heart tissue on the left ventricular side, with tether 150 extending from one side of body stent 110 to the outside of the heart and being anchored at the apex of the heart. Specifically, skirt hanger 120 extends radially outward from leaflet hanger 112, and skirt hanger 120 is farther from tether 150 than mount 130.

It should be noted that, in other embodiments, the fixing member 130 may be omitted. Skirt guard 120 of heart valve 10 may be snapped around the mitral annulus to prevent heart valve 10 from falling into the left ventricle, and tether 150 may be secured to the outside of the apex by knots to prevent heart valve 10 from moving to the left atrium, and skirt guard 120 and tether 150 may prevent heart valve 10 from shifting after implantation.

With continued reference to fig. 3, the main body support 110 includes a leaflet support 112, a connecting rod 114 and a connecting member 116, the skirt support 120 and the fixing member 130 are disposed on the leaflet support 112, one end of the connecting rod 114 is fixedly connected with one end of the leaflet support 112, the other end is connected with the connecting member 116, and the tether 150 is connected with the connecting member 116.

In the illustrated embodiment, the leaflet brace 112 is generally cylindrical having an inflow end and an outflow end opposite the inflow end. The leaflet brace 112 can provide radial support for the heart valve 10 and secure the leaflets 190. With continued reference to fig. 3, the leaflet brace 112 includes a wave ring 1121 and a connecting rod 1123. The leaflet brace 112 includes a plurality of wave rings 1121 spaced apart along an axial direction of the leaflet brace 112. The wave ring 1121 provides radial support force for the leaflet brace 112. In the illustrated embodiment, the leaflet brace 112 includes three bands 1121.

The three wave rings 1121 are fixedly connected by a plurality of connecting rods 1123. In the illustrated embodiment, the number of connecting rods 1123 is the same as the number of wave troughs of the wave rings 1121, and one connecting rod 1123 is fixedly connected with the wave troughs of three wave rings 1121 at the same time. Of course, in other embodiments, the connecting rod 1123 may be fixedly connected to other locations of the wave ring 1121, such as the wave crest.

The skirt hanger 120 includes a support portion 121 and a turn-up portion 122. The support portion 121 extends outward from the leaflet holder 112 in the radial direction of the leaflet holder 112, and the turnup portion 122 extends from an end of the support portion 121 remote from the leaflet holder 112 to an inflow end of the leaflet holder 112. The support 121 is used for fixation of the heart valve 10 to the mitral valve annulus of the heart in the human body, and the raised portion 122 is used to prevent abrasion of left atrial tissue by the edge of the skirt hanger 120. Without the cocking portion 122, the distal edge of the radial support portion 121 would be in direct contact with atrial tissue, which would have a cutting effect on atrial tissue during long-term heart beats, resulting in damage to atrial tissue. By providing the raised portion 122, the skirt hanger 120 is brought into surface contact with atrial tissue, increasing the contact area, reducing the contact pressure, and avoiding the cutting effect of the skirt hanger 120 on cardiac tissue, and the resulting abrasion.

The distance between the end of the support portion 121 of the skirt holder 120 near the leaflet holder 112 and the inflow end is 1/4 to 1/2 of the axial length of the leaflet holder 112. In the illustrated embodiment, the support portion 121 of the skirt support 120 is fixedly secured to the trough of the band 1121 near the first end of the leaflet support 112. In this way, when the heart valve 10 is implanted in the heart, approximately one-third of the axial dimension of the leaflet retainer 112 can be positioned in the left atrium, thereby avoiding narrowing or even obstruction of the left ventricular outflow tract due to excessive implantation in the left ventricle.

In this embodiment, the outer contour of the support portion 121 of the skirt holder 120 is circular as viewed from the inflow side of valve blood flow. Of course, in other embodiments, the outer contour of the supporting portion 121 may have other shapes, such as D-shape, or oval shape.

The flow-blocking member 170 serves to block blood flow from escaping through the valve holder 110, and cooperates with the leaflets 190 to ensure unidirectional flow of blood within the heart valve 10. The material of the flow resistor 170 is PTFE, PET, PU, casing or animal pericardium. The flow stop 170 may be bonded by a heat and pressure process, or may be secured to the valve holder 110 by stitching, depending on the material. In this embodiment, the flow resistor 170 covers the surfaces of the leaflet brace 112 and the skirt brace 120. In particular, the flow resistor 170 may cover only at least one of the inner and outer surfaces of the leaflet brace 112. In one embodiment, to accelerate the climbing of endothelial tissue on the surface of the heart valve 100, the non-biological tissue surface of the heart valve 100 is formed with a parylene layer. In one embodiment, the surface of the flow blocker 170 is formed with a parylene layer. The thickness of the parylene layer is 5 nanometers to 5 micrometers. Preferably, the material of the parylene layer is parylene type C.

The leaflet 190 is positioned inside the leaflet brace 112 and secured to the flow blocker 170 at the surface of the leaflet brace 112. The leaflets 190 are cut from the animal pericardium. In the present embodiment, the leaflet 190 has a substantially fan shape, and three sheets are arranged in this order in the circumferential direction of the leaflet holder 112. One end of each of the adjacent two leaflets 190 adjacent to the inner surface of the leaflet brace 112 is joined together to form a leaflet corner, the peripheral edges of the leaflets 190 being secured to the leaflet brace 112 and the flow stop 170 by stitching, and the leaflet corner being secured to the junction of the connecting rod 1123 and the leaflet brace 112.

Referring to fig. 2 and 3, the linkage 114 includes a proximal linkage 1141, a leaflet bracket linkage 1142, and a connector (not shown). The proximal link 1141 is generally rod-shaped. The leaflet bracket link 1142 is generally V-shaped and includes two branches extending from one end of the proximal link 1141 toward the leaflet bracket 112, one end of the two branches distal from the proximal link 1141 being fixedly connected to two troughs of the leaflet bracket 112 adjacent to the band near the outflow end, respectively, each trough being connected to one branch so that the plurality of links 114 are evenly distributed along the outflow end, thereby functioning as a guide when the heart valve 10 is received in the sheath, preventing the troughs from being stuck outside the sheath. If the leaflet brace rod 1142 is attached to the leaflet brace 112 near the peak of the band at the outflow end, the trough will become stuck outside the sheath when the heart valve 10 is being sheathed.

It will be appreciated that the leaflet brace rod 1142 may have other shapes, such as a straight shape, extending directly from one end of the proximal rod 1141 to connect with the valleys of the outflow end of the leaflet brace 112, i.e., the number of branch struts corresponds to the number of proximal rods 1141.

The structures of the leaflet holder 112, the link 114, the skirt holder 120, and the fixing member 130 of the valve holder 110 in the present application are not limited thereto, and the valve holder 100 may be adjusted as needed.

Referring to fig. 3, 5 and 6, the joint of the connecting rod 114 is connected to the connecting member 116. The connecting piece 116 comprises a plug-in seat 1161 and a connecting cover 1163 fixedly connected with the plug-in seat 1161, wherein the connecting cover 1163 is provided with a limiting hole 1162, and one end of the connecting rod 114, which is far away from the valve leaf bracket 112, penetrates through the limiting hole 1162 and is accommodated in a cavity formed by the connecting cover 1163 and the plug-in seat 1161.

The connecting cover 1163 comprises a connecting sleeve 11631 and a spherical crown 11633 formed at one end of the connecting sleeve 11631, one end of the connecting sleeve 11631 far away from the spherical crown 11633 is sleeved and fixed with the plug-in seat 1161 to form a cavity, and the limiting hole 1162 is a strip-shaped hole extending along the axial direction of the connecting sleeve 11631. The number of the connecting rods 114 is multiple, the number of the limiting holes 1162 is also multiple, the limiting holes 1162 are uniformly distributed along the circumferential direction of the connecting sleeve 11631, and the joint 1143 of each connecting rod 114 penetrates through one limiting hole 1162. The stop hole 1162 extends from an end of the connecting sleeve 11631 remote from the crown 11633 to a middle portion of the crown 11633 such that when the connecting rod 114 is connected to the connecting cap 1163, the angle of the connecting rod 114 may deflect at a small angle within the stop hole 1162, and the connecting rod 114 may adapt to different states of the heart valve 10 through angle changes when the heart valve 10 is in a compressed state and an uncompressed state.

In the illustrated embodiment, the plug block 1161 includes a main body portion 11611 and a plug portion 11613. The body portion 11611 is substantially hemispherical and planar at one end, and the diameter of the body portion 11611 is substantially the same as the diameter of the spherical cap 11633. The plug portion 11613 is protruding from a plane of the main body portion 11611, and has a diameter smaller than that of the main body portion 11611. The plug 11613 is accommodated in the connecting sleeve 11631 and both are fixed by welding. Screw holes 11614 are formed in the plug base 1161, and screw holes 11614 penetrate through the plug base 11613 and the main body 11611.

In the illustrated embodiment, the connector 116 further includes a flap 1165. The blocking piece 1165 is accommodated in the connecting sleeve 11631, and is located at one end of the plugging portion 11613 near the spherical cap 11633. A through hole 11651 corresponding to the screw hole 11614 is formed in the middle of the blocking piece 1165. Of course, the blocking piece 1165 may be omitted.

Both ends of the connector 116 are hemispherical, which reduces thrombosis and reduces the effects on hemodynamics.

One end of the tether 150 is inserted into the screw hole 11614 and is accommodated in a cavity formed by the connecting cover 1163 and the inserting seat 1161, and the other end extends out of the connecting piece 116 and penetrates through the apex of the heart to be knotted and fixed at the position of the apex of the heart, so that the heart valve 10 is pulled and prevented from falling off in the left atrium. Tether 150 is visible under X-rays.

In one embodiment, referring to fig. 4, the heart valve 10 may further include a spacer 180. The material of the spacer 180 is at least one selected from silica gel, terylene, nylon, ultra-high molecular weight polyethylene, nickel titanium and stainless steel braided wires. The spacer 180 may be a felt-shaped disc, a titanium-nickel wire woven disc-shaped structure or a high polymer material injection-molded disc-shaped structure. When heart valve 10 is implanted in a human heart, the end of tether 150 distal from linkage 114 is threaded through heart and spacer 180 and then knotted to secure to spacer 180.

During implantation of the heart valve 10, during diastole, the atria begin to contract and blood within the atria is ejected into the ventricles, causing ventricular pressure to rise. While during ventricular systole, blood enters the aorta from the left ventricle through the aortic valve, and the pressure generated by the contraction of the left ventricle causes the blood to enter the capillaries. Tether 150 exerts a pulling force on heart valve 10 during diastole and systole, and if tether 150 is weak in tension with heart valve 10, the fit of heart valve 10 to the mitral valve will be gapped, which will cause blood to flow directly from the gap between heart valve 10 and the mitral valve to the atrium without passing through heart valve 10, causing abnormal heart function. By arranging tether 150 to be visible under X-rays, the state of tether 150 is observed by X-rays during implantation, and if tether 150 is twisted or bent under X-rays, tether 150 can be pulled so as to be straight at this time, ensuring proper tension between tether 150 and valve holder 100, so as to ensure that heart valve 10 does not suffer from poor fit under the impact of blood flow, and reducing the probability of paravalvular leakage. If the tether 150 is not visible under X-ray, such as when the tether 150 is twisted or bent, the tether 150 is straightened under the impact of blood flow during ventricular systole, so that gaps appear between the attachment of the heart valve 10 and the mitral valve to cause paravalvular leakage, which affects heart function. Further, by arranging tether 150 to be visible under X-rays, it is also possible to determine whether paravalvular leakage is occurring by observing the state of tether 150 during a follow-up.

In particular, tether 150 may be made of a polymer doped with a developing material. For example, the tether 150 is produced by dispersing the developing material in a polymer matrix having good biocompatibility. The polymer matrix may be silica gel, polypropylene (PP), polyurethane (PU), polyethylene (PE), polyetheretherketone (PEEK), polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), polydioxanone (PDO), polycaprolactone (PCL), or Ultra High Molecular Weight Polyethylene (UHMWPE). The developing material may be gold, tungsten, iron, platinum, titanium, their alloys, stainless steel, or nonmetallic material such as barium sulfate, bismuth subcarbonate, iodide (such as iohexol, iopamidol). The mass of the developing material in tether 150 is not less than 10% of the mass of tether 150 to improve the developability of tether 150 under X-rays. Tether 150 has a wire diameter of 0.02mm to 5.0mm to enable normal delivery of tether 150 in a delivery device.

In one embodiment, tether 150 is made of polyurethane doped with barium sulfate, which may be prepared in two steps. The first step is melt granulation. Firstly, polyurethane and barium sulfate are dried, the drying temperature can be 60-140 ℃, the drying time can be 2-8 hours, the dried polyurethane and barium sulfate are poured into a single screw or a double screw, the temperature of an extruder is controlled to be 120-200 ℃ (the temperature of a feeding section is not excessively high, the temperature of a die head is generally controlled to be 120-150 ℃), the temperature of the die head is 160-190 ℃, the polyurethane is plasticized and homogenized through the extruder, extruded from the die head, and cut through a cutter, and granulation is completed. In this example, the feed ratio of polyurethane to barium sulfate was 40:60, the temperature of the feed section was 145 ℃, the temperature of the melt section was 165 ℃, the temperature of the homogenization section was 175 ℃, and the temperature of the handpiece was 170 ℃. The second step is extrusion molding. And (3) drying the particles manufactured in the step one, wherein the drying temperature can be 60-140 ℃, the drying time can be 2-8 hours, adding the dried particles into a single screw extruder, controlling the temperature of the extruder to 120-200 ℃, controlling the rotating speed of the screw to 0-60 rpm, and controlling the traction rate to 0-200 m/min to obtain the tether 150. In this example, the temperature of the feed section was controlled at 140 ℃, the temperature of the melt section was controlled at 160 ℃, the temperature of the homogenizing section was controlled at 180 ℃, the temperature of the head was controlled at 170 ℃, the screw speed was 30rpm, the pulling speed was 10m/min, and the wire diameter of the finally obtained tether was 0.15mm.

Referring to fig. 7, the second embodiment of the present application is different from the first embodiment mainly in that the tether 250 includes a developed line 251 and a non-developed line 252, and the developed line 251 and the non-developed line 252 are woven to form the tether 250, such as twisting, warp knitting, weft knitting, etc. In the illustrated embodiment, the developed lines 251 and the non-developed lines 252 are woven by twisting. At least 1 developing line 251 and at least 1 non-developing line 252 are each formed, and the twisting direction may be S, Z. In order to ensure that the twisted tether 250 is not easily dispersed and has less internal stress, the twist should be moderately controlled, preferably 1 to 100 twist per meter. In the embodiment, the development line 251 is nickel titanium wire with a diameter of 0.1mm; the non-developing line 252 is a nylon line with a specification of 80D/20F;1 developed wire 251 and 3 undeveloped wires 252 were twisted in the S direction with a twist of 50 pieces/m to produce tether 150, with a wire diameter of 0.3mm.

The prepared tether 250 is knotted, and compared with the developing line 251, referring to fig. 8 and 9, the developing line 251 is knotted alone to form a larger gap, the knot is easy to be dispersed in the stretching process, the gap formed after the tether 250 is knotted is smaller, and the knotting performance is greatly improved.

Of course, in other embodiments, the development line 251 may be made of other metal materials, such as gold, tungsten, iron, platinum, titanium and its alloy, stainless steel, and the like, and may be made of polymer material doped with the development material. The non-developing line 152 may also be made of silica gel, polypropylene (PP), polyurethane (PU), polyethylene (PE), polyetheretherketone (PEEK), polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), polydioxanone (PDO), polycaprolactone (PCL), or Ultra High Molecular Weight Polyethylene (UHMWPE).

Referring to fig. 10, the difference between the third embodiment and the first embodiment of the present application is that the tether 350 includes a core layer 353 and a braid 354 wrapped around the core layer 353, the core layer 353 is made of a polymer material doped with a developing material, and the braid 354 is braided by a polymer yarn. The tether can be seen under X rays, the defect that the metal tether is difficult to knot and the mechanical property of the polymer developing tether is reduced after the developer is added can be overcome, and better knotting performance and mechanical property are achieved.

For example, the core layer 353 is formed by dispersing the developing material in a polymer matrix having good biocompatibility. The polymer matrix may be silica gel, polypropylene (PP), polyurethane (PU), polyethylene (PE), polyetheretherketone (PEEK), polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), polydioxanone (PDO), polycaprolactone (PCL), or Ultra High Molecular Weight Polyethylene (UHMWPE). The developing material may be gold, tungsten, iron, platinum, titanium, their alloys, stainless steel, or nonmetallic material such as barium sulfate, bismuth subcarbonate, iodide (such as iohexol, iopamidol). The mass of the developing material in the core layer 353 is not less than 10% of the mass of the core layer 353 to improve the developability of the tether 350 under X-rays. The polymer lines of the braid 154 may be prepared by injection molding, extrusion, 3D printing, laser cutting, electrospinning, etc., and the material may be various materials with good biocompatibility, including but not limited to ultra-high molecular weight polyethylene (UHMWPE), polytetrafluoroethylene (PTFE), nylon (PA), polyethylene terephthalate (PET), polypropylene (PP), polyurethane (PU), polyethylene (PE), polyetheretherketone (PEEK), polylactic acid (PLA), polyglycolic acid (PGA), polyhydroxyalkanoate (PHA), polydioxanone (PDO), or Polycaprolactone (PCL). The polymer yarn may be woven into a woven layer 354 outside the core layer 353 by warp and weft knitting.

In one embodiment, the core 353 is made of polypropylene doped with tungsten powder by 3D printing, and the braid 354 is made of ultra-high molecular weight polyethylene strands by one-to-one braiding, as follows. Firstly, drying polypropylene and tungsten powder, wherein the drying temperature can be 60-140 ℃, the drying time can be 2-8 hours, pouring the dried polypropylene and tungsten powder into a single screw or a double screw, controlling the temperature of an extruder to be 150-230 ℃ (wherein the temperature of a feeding section is not excessively high, generally controlling the temperature to be 150-200 ℃), plasticizing and homogenizing the polypropylene through the extruder at the die head temperature of 190-230 ℃, extruding the polypropylene from the die head, and cutting the polypropylene by a cutter to complete granulation. In this example, the ratio of polypropylene to tungsten powder was 80:20, the temperature of the feed section was 190 ℃, the temperature of the melt section was 200 ℃, the temperature of the homogenization section was 210 ℃, and the temperature of the nose was 200 ℃. And drawing a three-dimensional entity model of the development polymer connecting line 81 by using three-dimensional design software such as UG, solidworks, pro-E, storing the three-dimensional entity model in a stl format, introducing slicing software, placing dried polypropylene particles in a material feeding device of a 3D printer, and controlling proper technological parameters such as printing filling density, printing temperature, printing speed and the like in order to ensure the integrity of the printed connecting line. For example, the printing temperature is controlled to be 170-250 ℃, the printing filling density is controlled to be 50-90%, and the printing speed is controlled to be 50-200 mm/s. In this example, the printing temperature was controlled at 200℃and the printing packing density was 70% and the printing speed was 50mm/s. Finally, the stl model and the process parameters are generated into a 3D printing path file Gcode by using slicing software, and a 3D printer prints a core layer 353 with a wire diameter of 0.1mm under the control of codes. The core 353 is placed in the center of the strands, the strands are woven around the core, the strands may be any double number, and the weaving may be, but not limited to, press weaving, such as one-press-one, one-press-two, such that the strands interpenetrate and interweave with each other to produce a woven rope. Referring to fig. 11, 8 strands are woven, 4 strands (numbered b, d, f, h) are woven along the same direction and the other 4 strands (numbered a, c, e, g) are woven along the symmetrical direction, 8 strands and one end of the core layer 153 are fixed together during weaving, b strands are woven along the symmetrical direction with respect to a strands, c strands are woven along the symmetrical direction with respect to b strands, d strands are woven along the same direction with respect to b strands, c strands are woven along the same direction with respect to b strands, and finally a is woven along the symmetrical direction with respect to h strands, and the operation is repeated to obtain a tether with a wire diameter of 0.5mm.

The prepared tether and core layer were tested by a UTM-2460 universal tensile tester using the GB/T8834 test standard, the results of which are shown in FIG. 12. It was found that the elastic modulus of the core layer was only 1.1GPa, while the elastic modulus of the tether to which the high-molecular polyethylene braided wire was added was 107GPa. It can be seen from this that,

in other embodiments, the core layer 353 may be made of a polymer material without doping with a developing material, and the braid is braided with polymer wires doped with a developing material.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A heart valve, characterized in that it includes:

Valve stent, the valve stent includes a main body stent and a skirt stent provided on the main body stent, the skirt stent extends outward along the radial direction of the main body stent;

Leaflets, the leaflets are arranged in the main body stent; and

A tether, the tether is connected to the main body bracket, the tether is suitable for being fixed by knotting; the tether is visible under X-rays, the tether includes a core layer and a braided layer, the core The layer is made of polymer material doped with developing material, and the developing material is dispersed in the polymer material; the braided layer is wrapped around the core layer, and the braided layer is woven from polymer threads. .

2. The heart valve according to claim 1, wherein the mass of the developing material is not less than 10% of the mass of the core layer.

3. The heart valve according to claim 1, wherein the main body stent includes a leaflet stent, a connecting rod and a connecting piece, the skirt stent is disposed on the leaflet stent, and the connecting rod is One end is fixedly connected to one end of the leaflet support, the other end is connected to the connecting piece, and the tether is connected to the connecting piece.

4. The heart valve according to any one of claims 1 to 3, wherein the wire diameter of the tether is 0.02 mm to 5.0 mm.

5. A tether for the heart valve according to any one of claims 1 to 4, characterized in that it includes:

A core layer made of a polymer material doped with a developing material dispersed in the polymer material; and

A braided layer, the braided layer is wrapped around the core layer, and the braided layer is woven from polymer threads;

The tether is adapted to be secured by knotting.

6. The tether of claim 5, wherein the mass of the developing material is not less than 10% of the mass of the core layer.

7. The tether according to claim 6, wherein the wire diameter of the tether is 0.02 mm to 5.0 mm.