CN112932563A

CN112932563A - Degradable heart ventricular septal defect occluder and manufacturing method thereof

Info

Publication number: CN112932563A
Application number: CN202110139683.9A
Authority: CN
Inventors: 张健; 张瑾; 马彩霞; 张永凯; 程海波; 杨晨
Original assignee: Shanghai Jinkui Medical Devices Co ltd
Current assignee: Shanghai Jinkui Medical Devices Co ltd
Priority date: 2021-02-01
Filing date: 2021-02-01
Publication date: 2021-06-11

Abstract

The invention provides a degradable heart ventricular septal defect occluder and a manufacturing method thereof. The degradable heart ventricular septal defect occluder comprises: a main body component, a flow impeding component, and a suture; the net body comprises a first disc-shaped part, a tubular part and a second disc-shaped part which are sequentially connected, the first disc-shaped part and the second disc-shaped part are both double-layer net surfaces, and two ends of the tubular part are respectively connected to the first disc-shaped part and the second disc-shaped part; wherein, the degradable heart ventricular septal defect occluder is made of a special mould; the special mould comprises a core mould; the core mold comprises: a first cover, a central member, a second cover, and an annular outer peripheral member; the central member is disposed inside the outer peripheral member, and an intermediate annular space, a first annular space, and a second annular space are formed between the outer peripheral wall of the central member and the inner peripheral wall of the outer peripheral member. The manufacturing method is simple and low in cost.

Description

Degradable heart ventricular septal defect occluder and manufacturing method thereof

Technical Field

The invention relates to a degradable heart ventricular septal defect occluder and a manufacturing method thereof.

Background

Ventricular septal defects are one of the common congenital heart diseases. The human heart is formed of four chambers (left atrium, left ventricle, right atrium and right ventricle) between which there should be an intact ventricular septum, which is called a ventricular septal defect if there is an opening in the ventricular septum. The ventricular septal defect is mainly formed in the growth and development process of a fetus, and is formed because the development of a heart is influenced by certain factors. In the case of a ventricular septal defect, blood will generally flow from the left ventricle through the septal defect and into the right ventricle, causing the right ventricle to increase in blood volume. Prolonged presence of ventricular septal defects can cause pulmonary arterial pressure elevation, congestive heart failure, palpitation, asthma, fatigue, repeated pulmonary infections, and the like. The thickness of the apex of the heart from the top to the bottom of the heart chamber interval is increased from thin to thick, the part with the thin heart chamber interval is called the diaphragm part between the heart chambers, and the part with the thick heart chamber interval is called the septal muscle part between the heart chambers.

Ventricular septal defects are common congenital heart diseases, and the traditional treatment mode is surgery. The surgical treatment method, in which the patient needs to be surgically opened, has the greatest disadvantages that: (1) extracorporeal circulation is needed during the operation, which may cause complications and death; (2) the surgical operation has large wound and scars are left after the operation; (3) the surgery is expensive.

With the development and improvement of catheter interventional diagnosis and treatment technology in the 80 s of the 20 th century, the minimally invasive interventional technology is gradually introduced to treat congenital heart diseases in China, and the method for treating ventricular septal defect through minimally invasive intervention is rapidly developed and is mature. Compared with the traditional surgical operation, the minimally invasive interventional therapy is modern high-tech minimally invasive therapy, the arteriovenous track is established by adopting a guide steel wire under the guide of medical imaging equipment through femoral vein puncture, then a conveying catheter is placed at the ventricular septal defect part along the guide steel wire, and finally the ventricular septal defect stopper is pushed to the ventricular septal defect part in the conveying catheter to implement the plugging therapy. The minimally invasive interventional therapy has the advantages of no operation, small wound, less complication, quick recovery, good effect, wide range of indication, relatively low operation cost and the like.

The treatment method of implanting the ventricular septal defect occluder through minimally invasive intervention surgery has many advantages over traditional surgery. However, since the main stent of the ventricular septal defect occluder used in clinical practice is mainly made of nitinol wires, and since such metallic materials cannot be degraded, the metallic materials react with human tissues to inflammation, blood coagulation and the like after long-term implantation, and even damage to a certain extent occurs, there are certain disadvantages, and there may still be the following risks: (1) the nickel-titanium alloy is a non-degradable metal alloy material, and although the biocompatibility of the nickel-titanium alloy is demonstrated, the long-term risk of long-term permanent implantation cannot be completely controlled; (2) since the nickel-titanium alloy is permanently implanted and is not degradable, the safety of the permanently-retained heart to the human body and the influence of the heart occluder with fixed size on the continuously-growing heart of the child lack long-term follow-up data, which may influence the development and growth of the heart of a patient who is not developed to maturity; (3) there is no clear scientific demonstration of complications such as nickel precipitation and nickel allergy.

After the surface of the cardiac occluder is completely endothelialized and the cardiac defect is repaired by the body's own tissue, the cardiac occluder does not have to remain in the body at all. Therefore, the ideal heart plugging device should provide a temporary bridge for self-repair of the heart, and be degraded by the body after the completion of the historical mission, so that the defect is completely repaired by the self-tissue, thereby avoiding long-term complications and potential safety hazards caused by the retention of metal in the body.

The support structure of the degradable occluder introduced in the U.S. Pat. No. 3, 08480709, 2 is formed by cutting a tube, the connecting point of the two disc surfaces of the occluder is similar to a double welding point, so that the center of the two disc surfaces is raised, the risk of local thrombosis on the surface of the occluder is increased, the endothelialization process on the surface of the occluder is not facilitated, meanwhile, the release length of the occluder is longer in the process of implantation surgery, the heart tissue is easily damaged, and the occluder manufactured by the method has poor compliance and recoverability, and needs to be assisted to recover the original shape by a locking device.

In addition, the cost of the current degradable heart occluder is too high, and the self-expansion recovery of the product is not good, which is caused by the existing manufacturing process, so that it is expected that a degradable heart occluder with lower cost and higher reliability can be designed.

Disclosure of Invention

The invention aims to solve the technical problem that the existing ventricular septal defect occluder used clinically has long-term risk and overcome the defects of poor compliance and recoverability of the degradable occluder in the prior art, and provides a degradable ventricular septal defect occluder and a manufacturing method thereof.

The invention solves the technical problems through the following technical scheme:

a degradable ventricular septal defect occluder, comprising: a main body component, a flow impeding component, and a suture; the main body component comprises a net body and a connecting piece connected to the net body, the net body comprises a first disc-shaped part, a tubular part and a second disc-shaped part which are sequentially connected, the first disc-shaped part and the second disc-shaped part are both double-layer net surfaces, and two ends of the tubular part are respectively connected to the first disc-shaped part and the second disc-shaped part; wherein the flow resisting part is at least two layers of degradable films or non-degradable films for resisting the blood flow; wherein the suture is a degradable suture or a non-degradable suture for sewing the flow resisting part on the main body part and serving as a closing line;

wherein, the degradable heart ventricular septal defect occluder is made of a special mould;

the special mold comprises a core mold;

the core mold includes: a first cover, a central member, a second cover, and an annular outer peripheral member;

the first cover body covers the first opening of the outer peripheral component in the axial direction, the second cover body covers the second opening of the outer peripheral component in the axial direction, the central component is arranged in the outer peripheral component, an intermediate annular gap is formed between the outer peripheral wall of the central component and the inner peripheral wall of the outer peripheral component and used for forming the tubular part, a part, close to the first opening, of the inner peripheral wall of the outer peripheral component is provided with a first step surface extending towards the outer peripheral direction, the first annular gap is formed between the first step surface and the inner side surface of the first cover body and used for forming the first disc-shaped part, a part, close to the second opening, of the inner peripheral wall of the outer peripheral component is provided with a second step surface extending towards the outer peripheral direction, and the second annular gap is formed between the second step surface and the inner side surface of the second cover body, the second annular void is for forming the second disc.

Preferably, the net surface of the second disk-shaped portion, which is far away from the tubular portion, is provided with a closing end, the closing end is a plurality of sequentially adjacent annular net wires, the disk-shaped portion is further provided with a closing line, the closing line penetrates through all the annular net wires, and after the closing line closes, the outer net surface of the disk-shaped portion forms a continuous and flat net surface.

In the scheme, the outer mesh surface of the second disc-shaped part is continuous and flat without convex connection points, the disc surface supporting force and the shape self-expansion resilience of the occluder can be increased, the risk of local thrombosis on the surface of the occluder can be reduced, the endothelial progress on the surface of the occluder can be accelerated, the heart ventricular septal defect can be repaired by self tissues earlier, and the healing time is shorter. In addition, the release length of the occluder in the operation process is reduced, the damage to the heart can be greatly reduced, and the operation is more effective and safer.

Preferably, a connecting piece is arranged at the center of the net surface of the first disc-shaped part, which is far away from the tubular part, and an internal thread is arranged at one end of the connecting piece, which is far away from the first disc-shaped part;

preferably, the length of the tubular portion is 3.5-9.5 mm.

Preferably, the outer diameter of the second disc portion is larger or of equal diameter than the outer diameter of the first disc portion. In the scheme, the second disc-shaped part is positioned in the left ventricle, the first disc-shaped part is positioned in the right ventricle, and for a patient with ventricular septal defect, blood can flow into the right ventricle from the left ventricle through the ventricular septal defect generally. Meanwhile, the traction on surrounding tissues can be avoided, and the damage to the surrounding tissues is reduced.

Preferably, the center of the first cover body is provided with a yielding hole, and the yielding hole is used for accommodating the connecting piece;

and/or the presence of a gas in the gas,

one or more vent holes are formed in the first cover body, penetrate through the first cover body and communicate the inside and the outside of the core mold.

Preferably, the first cover body is provided at a center thereof with a first protrusion protruding toward an inside of the core mold;

preferably, the central part is an annular member, and the first projection is inserted into a central hole of the annular member;

preferably, the center member includes a first center piece and a second center piece, the first center piece and the second center piece are stacked and have overlapping axes, an outer peripheral surface of the first center piece is disposed more radially inward than an outer peripheral surface of the second center piece, and the first center piece is closer to the first lid body than the second center piece.

Preferably, a second protruding portion is arranged on the second cover body, the second protruding portion is clamped in a central hole of the second central piece, and the first protruding portion is clamped in a central hole of the first central piece.

Preferably, a positioning hole is formed in the center of the second cover body, and the positioning hole is used for adjusting the closing-in position on the disc-shaped portion.

Preferably, the first cover and/or the second cover are engaged with the outer peripheral member.

Preferably, the outer peripheral part comprises two semi-circular portions spliced together.

Preferably, the special mold further comprises a shell, a plurality of heating pipes are inserted into the wall surface of the shell, and a cooling pipeline is further arranged in the wall surface of the shell;

the core die is accommodated in the inner cavity of the shell;

a rest stand is arranged in the inner cavity, and at least four core molds can be placed on the rest stand;

preferably, the shell is also provided with an air inlet for introducing inert gas;

preferably, the housing includes a cover plate and a frame, the cover plate is covered on an upper opening of the frame, the heating pipe is arranged in a wall surface of the frame, and the cooling pipeline is arranged in the wall surface of the frame;

preferably, in the wall surface, the cooling line is provided inside the heating pipe.

A method of manufacturing a degradable ventricular septal defect occluder, the degradable ventricular septal defect occluder comprising: a main body component, a flow impeding component, and a suture; the main body component comprises a net body and a connecting piece connected to the net body, the net body comprises a first disc-shaped part, a tubular part and a second disc-shaped part which are sequentially connected, the first disc-shaped part and the second disc-shaped part are both double-layer net surfaces, and two ends of the tubular part are respectively connected to the first disc-shaped part and the second disc-shaped part; wherein the flow resisting part is at least two layers of degradable films or non-degradable films for resisting the blood flow; wherein the suture is a degradable suture or a non-degradable suture for sewing the flow resisting part on the main body part and serving as a closing line;

the manufacturing method comprises the following steps:

weaving the degradable filaments into a tubular mesh body by using a die rod, wherein the number of the woven meshes of the tubular mesh body is 20-144, grooves extending according to the direction of the degradable filaments are formed in the peripheral surface of the die rod so as to standardize the direction of the filaments, and the die rod is provided with a gas through hole extending along the central axis of the die rod;

shaping the tubular net body at 35-200 deg.C for 1-60 min;

after the connecting piece is manufactured, one end of the tubular net body is provided with the connecting piece, and the other end of the tubular net body is a retractable open end;

placing the tubular net body into a special mould, and heating and shaping to make the net body have a first disc-shaped part, a tubular part and a second disc-shaped part, wherein the shaping temperature is 35-200 ℃, and the shaping time is 1-60 min;

wherein the content of the first and second substances,

the special mold comprises a core mold;

the first cover body covers the first opening of the outer peripheral component in the axial direction, the second cover body covers the second opening of the outer peripheral component in the axial direction, the central component is arranged in the outer peripheral component, an intermediate annular gap is formed between the outer peripheral wall of the central component and the inner peripheral wall of the outer peripheral component and used for forming the tubular part, a part, close to the first opening, of the inner peripheral wall of the outer peripheral component is provided with a first step surface extending towards the outer peripheral direction, the first annular gap is formed between the first step surface and the inner side surface of the first cover body and used for forming the first disc-shaped part, a part, close to the second opening, of the inner peripheral wall of the outer peripheral component is provided with a second step surface extending towards the outer peripheral direction, and the second annular gap is formed between the second step surface and the inner side surface of the second cover body, the second annular void is for forming the second disc; and vent holes are formed in the first cover body and the second cover body.

The positive progress effects of the invention are as follows:

the plugging device is formed by weaving high-molecular degradable filaments, the biodegradation period is 6 months to 2 years, the plugging device can be completely absorbed in a human body, and the long-term influence of foreign matters implanted on the human body is avoided. The degradable or human body absorbable material used in the invention is nontoxic and harmless to human body and has good biocompatibility. If the flow resisting part and the suture line of the occluder are made of biodegradable materials, the biodegradation period is 6 months to 2 years, and the plugging agent is degraded and disappears in vivo after the treatment mission is finished in a human body without residual foreign matters. The net body at the center of the outer net surface of the first disc-shaped part is subjected to high-temperature hot melting to form a connecting piece, and particularly, the net body at the center of the outer net surface of the first disc-shaped part is subjected to high-temperature hot melting, and the hot-melted net body is shaped into the connecting piece by using a mold, so that the degradable filaments forming the disc-shaped part are not easy to scatter and can be firmly connected together; meanwhile, the connecting piece and the degradable filaments forming the disc-shaped part can be firmly connected together and are not easy to fall off. The net surface without the connecting piece adopts a closing-in structure of a closing-in line, so that the outer net surface is smoother, the supporting force and the resilience of the occluder can be increased, the risk of local thrombus formation on the surface of the occluder can be reduced, the endothelialization process on the surface of the occluder can be accelerated, and the heart ventricular septal defect can be repaired by self tissues earlier. Meanwhile, the release length of the occluder in the operation process is reduced, the damage to the heart can be greatly reduced, and the operation is more effective and safer; in addition, the plugging device also has the advantage of low manufacturing cost.

Drawings

Figure 1 is a schematic perspective view of a degradable ventricular septal defect occluder in accordance with an embodiment of the present invention.

Figure 2 is a schematic view of a degradable ventricular septal defect occluder viewed from the second disc side in accordance with an embodiment of the present invention.

FIG. 3 is an enlarged partial view of the closing end of the outer web surface of the second disk portion in accordance with the preferred embodiment of the present invention.

Figure 4 is a schematic structural diagram of a mold rod for weaving a degradable heart ventricular septal defect occluder.

Figure 5A is a circuit diagram of the weaving starting points on the mold bar for weaving a degradable heart ventricular septal defect occluder.

Figure 5B is a circuit diagram of another weaving starting point on a die bar for weaving a degradable heart ventricular septal defect occluder.

Fig. 6 is a schematic view of the weaving effect on the mold bar.

Fig. 7 is a schematic perspective view of a dedicated mold according to an embodiment of the present invention.

Fig. 8 is a schematic sectional structure view of a dedicated mold according to an embodiment of the present invention.

Fig. 9 is a schematic structural view of a jig according to an embodiment of the present invention.

Fig. 10 is a schematic cross-sectional structure of a core mold according to an embodiment of the present invention.

Fig. 11 is an exploded view of a core mold according to an embodiment of the present invention.

Fig. 12 is a schematic view of heat conduction inside the core mold.

Fig. 13 is a schematic structural diagram of the tubular net body after the connecting piece is manufactured.

Figure 14 is a schematic diagram of the sheath exit of the degradable ventricular septal defect occluder.

Description of reference numerals:

ventricular septal defect occluder 100

First disk portion 10

Recess 11

Second disk 20

Closing end 21

Ring network cable 22

Closing line 23

Tubular part 30

Connecting piece 40

Special mold 200

Core mold 201

First cover 203

First protrusion 204

Abdication hole 205

Vent 206

Second cover 207

Second projection 208

Positioning hole 209

Center part 211

First centerpiece 212

Second centerpiece 213

Outer peripheral member 214

First step surface 2141

Second step surface 2142

Semicircular part 215

First opening 216

Second opening 217

Intermediate annular space 218

First annular gap 219

Second annular void 220

Clamp 221

Clamping plate 223

Adjustable fastener 224

Outer casing 241

Cover plate 243

Frame 244

Shelf 246

Heating pipe 251

Cooling circuit 252

Air inlet 253

Mold bar 300

Groove 301

Detailed Description

The present invention will be more clearly and completely described in the following description of preferred embodiments, taken in conjunction with the accompanying drawings.

As shown in fig. 1-3, a degradable heart ventricular septal defect occluder 100 comprises: a main body part, a flow blocking part (not shown), and a suture (not shown); the main body part comprises a net body and a connecting piece 40 connected to the net body, the net body comprises a first disc-shaped part 10, a tubular part 30 and a second disc-shaped part 20 which are sequentially connected, the first disc-shaped part 10 and the second disc-shaped part 20 are both double-layer net surfaces, and two ends of the tubular part 30 are respectively connected to the first disc-shaped part 10 and the second disc-shaped part 20; wherein the flow resisting part is at least two layers of degradable films or non-degradable films for resisting the blood flow; wherein the suture is degradable suture or non-degradable suture for sewing the flow resisting part on the main body part and serving as a closing line.

The net surface of the second disk-shaped portion 20 far away from the tubular portion 30 is provided with a closing end 21, the closing end 21 is a plurality of sequentially adjacent annular net wires 22, the second disk-shaped portion 20 is further provided with a closing line 23, the closing line 23 penetrates through all the annular net wires 22, and the outer net surface of the disk-shaped portion forms a continuous and flat net surface after closing by the closing line 23.

The center of the net surface of the first disk-shaped part 10 far away from the tubular part 30 is provided with a connecting piece 40, and one end of the connecting piece 40 far away from the first disk-shaped part 10 is provided with an internal thread. The first disc portion 10 also has a recess 11 in the centre of its web facing away from the tubular portion 30, the connector 40 being located in the recess 11.

The outer diameter of the second disk 20 is larger or of equal diameter than the outer diameter of the first disk 10.

The degradable heart ventricular septal defect occluder 100 is characterized in that the net body at the center of the net surface of the first disc part 10 far away from the tubular part 30 is hot-melted at high temperature to form the connecting piece 40, specifically, the net body at the center of the net surface of the first disc part 10 far away from the tubular part 30 is hot-melted at high temperature, and the hot-melted net body is shaped into the connecting piece 40 by a mould, so that degradable filaments forming the disc parts are not easy to scatter and can be firmly connected together; meanwhile, the connecting piece 40 and the degradable filaments forming the disc-shaped part can be firmly connected together and are not easy to fall off. In the present embodiment, the mesh surface close to the tubular portion 30 of the two opposite mesh surfaces of the first disk portion 10 and the second disk portion 20 is an inner mesh surface, and the mesh surface far from the tubular portion 30 is an outer mesh surface.

The connecting piece 40 is tubular, the height is 1.5-2.0mm, and the outer diameter is 2.5-3.2 mm. The web side of the first disk portion 10 provided with the attachment 40 is recessed inwardly. The outer diameter of the second disc 20 is larger or equal than the outer diameter of the first disc 10; the length of the tubular portion 30 is 3.5-9.5 mm. When the length is 3.5-5.5mm, the thickness of the interventricular septal membrane defect tissue corresponds to the thickness of the interventricular membrane defect tissue; the length of the tissue is 6.0-9.5mm, which corresponds to the thickness of the interventricular septal muscle defect tissue. The connector 40 is tubular and the connector 40 is internally threaded at the end opposite the web side to which it is attached.

The connecting piece 40 is formed by hot melting degradable filaments, and the using conditions are required to be met, so that the pushing of the ventricular septal defect occluder 100 in a conveying sheath cannot be hindered due to an overlarge structure, and the pulling-out of the connecting piece 40 caused by insufficient connecting strength is also avoided.

TABLE 1 test chart of size, tensile strength and pushing force of connecting piece 40 in conveying sheath

Tests have found that a pull-off resistance of up to 15N ensures that the connector 40 is not pulled off during use. It can be seen from the above table 1 that the size of the connecting member 40 directly affects whether the ventricular septal defect occluder 100 can be used in normal operation. Improper sizing of the connector 40 can result in the connector 40 being pulled off or not being pushed into the delivery sheath, which can render the product unusable.

The outer net surface of the second disc part 20 of the heart ventricular septal defect occluder 100 is a continuous net surface, and the net surfaces of the second disc part 20 are closed by adopting closing lines, so that the net surface of the second disc part 20 far away from the tubular part is a flat and smooth net surface without bulges, the structure is favorable for improving the shape recovery and the supporting force of the heart ventricular septal defect occluder 100, and is more favorable for accelerating the endothelialization process of the surface of the heart ventricular septal defect occluder 100, and the heart defects are repaired by self tissues earlier. The heart ventricular septal defect occluder 100 of the present invention is formed by melting the mesh body at the center of the mesh surface of the first disk portion 10 far away from the tubular portion 30 into the connecting member 40 at a high temperature, specifically, by melting the mesh body at the center of the mesh surface of the first disk portion 10 far away from the tubular portion 30 at a high temperature and molding the melted mesh body into the connecting member 40 with a mold, so that the degradable filaments constituting the disk portions are not easily dispersed and can be firmly connected together; meanwhile, the connecting piece 40 and the degradable filaments forming the disc-shaped part can be firmly connected together and are not easy to fall off.

The main body component of the heart ventricular septal defect occluder 100 is made of degradable polymer filaments. The degradable silk is a biodegradable high molecular material, and is selected from polylactide, polyglycolide, polycaprolactone, polydioxanone, polyhydroxybutyrate, polyhydroxyalkanoate, polyanhydride, polyphosphate, polyurethane or polycarbonate, derivatives thereof, blends of more than two of the polyhydroxybutyrate, the polyhydroxybutyrate and the polyhydroxyalkanoate, or copolymers of corresponding monomers. The degradable flow blocking film filled in the heart ventricular septal defect occluder 100 is made of biodegradable materials such as polylactide, polycaprolactone, polyhydroxybutyrate, polydioxanone and the like, thereby playing a role in blocking blood flow. In an alternative embodiment, the heart ventricular septal defect occluder 100 can also be filled with a non-degradable flow-resistant film made of a non-biodegradable material such as polyethylene terephthalate, polytetrafluoroethylene or the like, so as to block blood flow. The degradable suture line can be made of biodegradable materials such as poly (ethyl propyl acetate), poly (lactide) and the like, and is used for sewing the flow resisting part on the main body part and closing as a closing line. In an alternative embodiment, a non-degradable suture thread, which is a non-biodegradable material such as polyethylene terephthalate, may be used to suture the flow-obstructing component to the main component and to act as a setback.

The outer mesh surface of the second disk-shaped part 20 of the heart ventricular septal defect occluder 100 is a continuous mesh surface, and the mesh surfaces of the second disk-shaped part 20 and the tubular part 30 are closed by adopting closing lines, so that the mesh surface of the second disk-shaped part 20, which is far away from the tubular part 30, is a flat and smooth mesh surface without protrusions, the structure is favorable for shape recovery and disc surface supporting force improvement of the heart ventricular septal defect occluder 100, and is more favorable for accelerating the endothelialization process of the surface of the heart ventricular septal defect occluder 100, and the heart defects are repaired by self tissues earlier.

The present embodiment also provides a method of manufacturing a degradable ventricular septal defect occluder 100.

The manufacturing method comprises the following steps:

weaving a tubular net body on a mold rod 300 by using degradable wires, wherein the mold rod 300 is shown in figure 4, a pin at one end of the mold rod 300 is taken as a starting point, the degradable wires are knotted on the pin at the starting point and fixed at the starting point, then the degradable wires are wound and woven on the mold rod 300 along a groove 301 on the mold rod 300, a first wire is wound along the mold rod for one circle as shown in figure 5A, a second wire is wound as shown in figure 5B, the mold rod 300 is provided with a groove 301 in a wire direction so as to standardize the wire direction until the weaving of the tubular net body is completed, and the woven tubular net body is shown in figure 6. The weaving method of the net body enables the net body to be more uniform in grid, is easy to operate and reduces the manufacturing cost. The net weaving number of the net body is 20-144, and the requirements of the supporting force and the oversheath size of the heart ventricular septal defect occluder 100 can be met. The support force of the ventricular septal defect occluder 100 can be improved by increasing the number of the braided degradable filaments, but the oversheath size can be increased, namely the diameter of the matched delivery sheath tube is larger, so that the range of indications is reduced; the reduced number of braided degradable filaments reduces the supporting force of the ventricular septal defect occluder 100, but reduces the oversheath size, i.e. the diameter of the matched delivery sheath is smaller, thereby improving the range of indications.

The braided tubular net body needs to be shaped at a certain temperature and time to keep the shape of the braided net body unchanged. The setting temperature of the tubular net body is 35-200 ℃, and the setting time is 1-60 min. In the design process, the mold rod 300 can support the net body and keep the shape of the net body unchanged, and simultaneously, the central axis department of mold rod 300 has the gas through hole, is favorable to the heat conduction inside and outside the mold rod 300, and the gas through hole of mold rod 300 makes the heat outwards diffuse by the central axis of mold rod 300, and the heat is also inwards diffused by the outside of mold rod 300 simultaneously, is favorable to realizing heat balance inside and outside the mold rod 300 so fast to guarantee that the net body is heated evenly and stereotypes fast. After setting is complete, the tubular mesh body is removed from the mandrel 300.

The connecting piece 40 is manufactured by filling one end of a tubular net body into a special pipeline, wherein the pipeline is used for fixing the net body, then the other end of the net body is fastened and is placed into a mould of hot melting equipment for manufacturing the connecting piece 40, the hot melting temperature is 40-200 ℃ above the melting point of the material, the hot melting time is 5-15s, and after the hot melting is finished, the mould is opened, and the net body is taken out, so that the manufacturing of the connecting piece 40 is finished. During the hot melting process, proper hot melting temperature and time need to be maintained because: excessive heat fusion can cause other degradable filaments except the mesh body at one end of the connecting piece 40 to be subjected to heat fusion together, so that the mesh body structure is damaged, the molecular weight of the degradable material of the connecting piece 40 part is greatly reduced, and premature degradation of the mesh body and the connecting piece 40 can be caused; on the contrary, insufficient hot melting can cause that the degradable filaments at the connecting piece 40 can not be fully hot-melted into a whole, and the complete internal thread structure of the connecting piece 40 can not be formed, so that the connecting strength between the connecting piece 40 and the conveying system is insufficient. Therefore, proper heat fusing temperature and time are required to complete heat fusing. The connector 40 may take other forms besides internal threads.

The manufacturing method of the connecting member 40 is easy to operate, the connecting member 40 with stable size can be obtained, the types of materials used on the heart ventricular septal defect occluder 100 are reduced, the degradable filaments forming the first disk-shaped part 10 can be firmly connected together, and the connecting member 40 and the degradable filaments forming the first disk-shaped part 10 can be firmly connected together and are not easy to fall off.

The net body is shaped to have a first disk portion 10, a tubular portion 30 and a second disk portion 20 using a special mold 200. As shown in figure 13, the net body with the connecting piece 40 is put into a special mould 200, then the net body is heated and shaped at the temperature of 35-200 ℃ for 1-60min, and the main body component of the heart ventricular septal defect occluder 100 is obtained by removing the special mould after shaping.

As shown in fig. 7-11, the special mold includes a core mold 201 and a shell 241.

The core mold 201 includes: a first cover 203, a central member 211, a second cover 207, and an annular outer peripheral member 214;

the first cover 203 covers a first opening 216 of the outer peripheral member 214 in the axial direction, the second cover 207 covers a second opening 217 of the outer peripheral member 214 in the axial direction, the central member 211 is provided inside the outer peripheral member 214, an intermediate annular space 218 is formed between the outer peripheral wall of the central member 211 and the inner peripheral wall of the outer peripheral member 214, the intermediate annular space 218 forms the tubular portion 30, a first step surface 2141 extending in the outer peripheral direction is provided on a portion of the inner peripheral wall of the outer peripheral member 214 close to the first opening 216, a first annular space 219 is formed between the first step surface 2141 and the inner side surface of the first cover 203, the first annular space 219 forms the first disc portion 10, a second step surface 2142 extending in the outer peripheral direction is provided on a portion of the inner peripheral wall of the outer peripheral member 214 close to the second opening 217, and a second annular space 220 is formed between the second step surface 2142 and the inner side surface of the second cover 207, the second annular void 220 is used to form the second disk 20.

The center of the first cover 203 is provided with a relief hole 205, and the relief hole 205 is used for accommodating the connecting piece 40.

One or more vent holes 206 are formed in the first cover 203, and the vent holes 206 penetrate through the first cover 203 and communicate the inside and outside of the core mold 201. The second cover 207 may be provided with a vent hole 206, and a positioning hole 209 described below may be used as the vent hole 206. The vent holes 206 are beneficial to the heat conduction in the special die, so that the heat is diffused outwards from the central axis of the die, and the heat diffused inwards from the outside of the die exists at the same time, thereby being beneficial to quickly realizing the heat balance inside and outside the die, and further ensuring that the net body can be heated uniformly and quickly shaped in the shaping process. The heat transfer in the mold is shown in FIG. 12.

The first cover 203 is provided at the center thereof with a first projection 204, and the first projection 204 projects toward the inside of the core mold 201. The first protrusion 204 is used to form a recess 11 at the center of the first cover 203 where the connecting member 40 is disposed.

The central part 211 is an annular member, and the first protrusion 204 is inserted into a central hole of the annular member; the center member 211 includes a first center piece 212 and a second center piece 213, the first center piece 212 and the second center piece 213 are stacked and axially overlapped, an outer peripheral surface of the first center piece 212 is disposed more radially inward than an outer peripheral surface of the second center piece 213, and the first center piece 212 is closer to the first cover 203 than the second center piece 213.

The first protrusion 204 is engaged with the central hole of the first central member 212, and the second cover 207 is provided with a second protrusion 208. Although it is not shown in fig. 10 and 12 that the second protrusion 208 is snapped into the central hole of the second centerpiece 213, in an alternative embodiment, the second protrusion 208 may be arranged to be snapped into the central hole of the second centerpiece 213. By providing the second protrusion 208, the mesh surface of the shaped second disc 20 facing away from the tubular part is slightly recessed inwards, counteracting the slight springback of the degradable ventricular septal defect occluder 100 after demolding.

In the present embodiment, the center member 211 includes the first center piece 212 and the second center piece 213 having different cross-sectional dimensions. In other alternative embodiments, the first centerpiece 212 and the second centerpiece 213 may be provided with the same cross-sectional dimensions. In another alternative embodiment, first centerpiece 212 and second centerpiece 213 may also be provided as a unitary structure.

The center of the second cover 207 is provided with a positioning hole 209, and the positioning hole 209 is used for adjusting the closing position on the second disc portion. After the net body is put into the core mold 201 and the core mold 201 is closed, the closing position of the net body can be adjusted by inserting a pin or the like into the positioning hole 209.

The first cover 203 and/or the second cover 207 are engaged with the outer peripheral member 214.

The outer peripheral part 214 comprises two semi-circular portions 215 spliced together. This further facilitates assembly of the various components of the core 201. When the outer peripheral member 214 includes the two semicircular portions 215 that are equally divided, a jig described below preferably also grips the outer peripheral member 214 from both sides of the two semicircular portions 215. In an alternative embodiment, the outer peripheral component 214 may also be a unitary component.

The dedicated mold 200 further comprises a clamp 221 clamping the first cover 203 and the second cover 207 towards the central part 211.

The jig 221 has two clamping plates 223 and adjustable fasteners 224 attached to the two clamping plates 223, respectively. The fasteners may be at least two, such as 2, 4, etc. The clamping plate can be clamped left and right or up and down.

The special mold 200 further includes a housing 241, a plurality of heating pipes 251 are inserted into a wall surface of the housing 241, and a cooling pipeline 252 is further provided in the wall surface of the housing 241. The core 201 is received in the inner cavity of the housing 241. The heating pipe 251 is generally an electric heating pipe 251, and can be pulled out from the wall surface to adjust the heating power. The shell 241 is preferably made of a material that conducts heat well so that the mandrel 201 inside it is heated uniformly. Similarly, the core mold 201 is also made of a material having good thermal conductivity.

The net body of the ventricular septal defect occluder 100 is heat-set by the heating pipe 251, and can be rapidly cooled after heat-set by the cooling pipeline 252, so that the molding effect of the ventricular septal defect occluder 100 is enhanced.

The casing 241 includes a cover plate 243 and a frame 244, the cover plate 243 covers an upper opening of the frame 244, the heating pipe 251 is provided in a wall surface of the frame 244, and the cooling pipe 252 is provided in a wall surface of the frame 244. The housing 241 is also provided with an inlet 253 for introducing inert gas into the interior of the housing. Through letting in inert gas, be favorable to getting rid of the steam in the inside air of shell, reduce the influence of steam to the dictyosome performance in the ventricular septal defect plugging device 100 design process, prevent that the dictyosome from taking place the degradation when stereotyping. The inert gas may be helium, neon, argon, krypton, xenon, radon, or the like.

In the wall surface, the cooling line 252 is provided inside the heating pipe 251. The cooling line 252 spirally surrounds the inner cavity of the housing 241 in the wall surface to enable rapid cooling of the wall surface.

When the special mold 200 is used to shape the ventricular septal defect occluder 100, first, as shown in fig. 13, the central member 211 is inserted into the net body through the open end of one end of the net body which can be contracted, then the connecting member 40 of the net body is inserted into the abdicating hole 205 of the first cover body 203, and the open end of the net body is closed, the two semicircular parts 215 are spliced into a complete peripheral member 214, then the net body is adjusted to be positioned on the disk surfaces of the two disk-shaped parts, the first cover body 203 is covered on the first opening 216 of the peripheral member 214, the second cover body 207 is covered on the second opening 217 of the peripheral member 214, and the closed position of the net body is adjusted through the positioning hole 209. By pressing the first cover body 203 and the second cover body 207 inward, the mesh body in the cavity between the inner surface of the first cover body 203 and the stepped surface 2141 of the outer circumferential member 214 and the mesh body in the cavity between the inner surface of the second cover body 207 and the stepped surface 2142 of the outer circumferential member 214 are radially expanded to form a disk-like portion.

As shown in fig. 13, one end of the net body has a connector 40, and the other end is a bunched open end that is bunched with one or more degradable or non-degradable filaments to close the net body or released to open the other end of the net body. The net wires can be constrained with each other, so that the net body is not loosened, the phenomenon that the net body woven by the double-rivet heart ventricular septal defect occluder machine is easy to loosen after being cut off is avoided, and the net body has higher stability in the process of adding and removing the die, so that the process and the operation are simplified.

The mandrel 201 is clamped using the clamp 221 and then the clamp 221 is placed into the internal cavity of the housing 241 with the mandrel 201. The housing 241 has a cavity in which a rest 246 is placed, and the jig 221 is placed on the rest 246. The shelf 246 has four platforms for placing the core mold 201, and at least four net bodies can be heat-set at one time, thereby improving the production efficiency and reducing the cost. Of course, the rest 246 may be provided in other forms to hold more core molds 201.

The heating pipe 251 is used to perform heating, and after a predetermined heating time, the heating is stopped, and a coolant is introduced into the cooling pipe, so that the core mold 201 is rapidly cooled.

The net body shaping method is easy to operate, and the manufactured heart ventricular septal defect occluder 100 is stable in size. The heart ventricular septal defect occluder 100 manufactured by the method has larger disc surface supporting force and better shape self-expansion resilience, thereby meeting the requirements of operation and ensuring that the operation is more effective and safer.

The shaped body part is sutured with sutures to the first and

second discs

10, 20, and/or the tubular portion 30 of the body part. Finally, the mesh surface of the second disk portion 20 remote from the tubular portion is closed up with a suture to form a continuous flat mesh surface.

The ventricular septal defect occluder 100 manufactured by the manufacturing method of the ventricular septal defect occluder 100 has a flat disc surface and no bulge; the supporting force of the ventricular septal defect occluder generally refers to the disc surface supporting force of the second disc part, through supporting force detection, the supporting force value of the ventricular septal defect occluder is greater than the pressure difference value of the defect part, the average value of the supporting force of the ventricular septal defect occluder is more than 1.5 times of the pressure difference value of the corresponding defect part, sufficient and stable supporting force can be ensured, the average value of the supporting force of the ventricular septal defect occluder before optimization is equal to or 1.1 times of the maximum pressure difference value of the corresponding defect part, and the supporting force is not stable enough; the sheath outlet process of the ventricular septal defect occluder 100 is shown in fig. 14, after the ventricular septal defect occluder 100 is received, pushed and released in a sheath tube, the shape can be recovered to the original shape, the average value of the sheath retracting force is about 5-6N, the sheath retracting is smooth and unimpeded, the ventricular septal defect occluder 100 can be ensured not to fall off on a conveying steel cable, the average value of the sheath retracting force before optimization is about 7-9N, and the sheath retracting force is larger; after the connecting component is connected with the conveying steel cable, the connecting component can be kept from being separated within 30s under the tension of 15N, and the interior of the net body is not broken; the plugging device can be completely stored after 4 years under the set storage condition, the mechanical property is met, and the molecular weight of the components of the heart ventricular septal defect plugging device 100 is reduced, but the use requirement is still met.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims

1. A degradable ventricular septal defect occluder, comprising: a main body component, a flow impeding component, and a suture; the main body component comprises a net body and a connecting piece connected to the net body, the net body comprises a first disc-shaped part, a tubular part and a second disc-shaped part which are sequentially connected, the first disc-shaped part and the second disc-shaped part are both double-layer net surfaces, and two ends of the tubular part are respectively connected to the first disc-shaped part and the second disc-shaped part; wherein the flow resisting part is at least two layers of degradable films or non-degradable films for resisting the blood flow; wherein the suture is a degradable suture or a non-degradable suture for sewing the flow resisting part on the main body part and serving as a closing line;

the special mold comprises a core mold;

the first cover body covers the first opening of the outer peripheral component in the axial direction, the second cover body covers the second opening of the outer peripheral component in the axial direction, the central component is arranged in the outer peripheral component, an intermediate annular gap is formed between the outer peripheral wall of the central component and the inner peripheral wall of the outer peripheral component and used for forming the tubular part, a first step surface extending towards the outer peripheral direction is arranged on the part, close to the first opening, of the inner peripheral wall of the outer peripheral component, a first annular gap is formed between the first step surface and the inner side surface of the first cover body and used for forming the first disc-shaped part, a second step surface extending towards the outer peripheral direction is arranged on the part, close to the second opening, of the inner peripheral wall of the outer peripheral component, and a second annular gap is formed between the second step surface and the inner side surface of the second cover body, the second annular void is for forming the second disc.

2. The degradable ventricular septal defect occluder of claim 1, wherein the second disk portion has a narrowed end on a mesh surface thereof away from the tubular portion, the narrowed end being a plurality of sequentially adjacent annular mesh wires, the disk portion further having a narrowed line passing through all of the annular mesh wires, and the outer mesh surface of the disk portion being formed into a continuous flat mesh surface after being narrowed by the narrowed line;

preferably, the length of the tubular portion is 3.5-9.5 mm;

preferably, the outer diameter of the second disc portion is larger or of equal diameter than the outer diameter of the first disc portion.

3. The degradable ventricular septal defect occluder of claim 2,

the center of the first cover body is provided with a yielding hole, and the yielding hole is used for accommodating the connecting piece;

and/or the presence of a gas in the gas,

4. The degradable ventricular septal defect occluder of claim 2, wherein the center of the first cap defines a first projection projecting toward the interior of the mandrel;

5. The degradable ventricular septal defect occluder of claim 4, wherein a second projection is provided on the second cap, the second projection being captured in the central bore of the second hub, and the first projection being captured in the central bore of the first hub.

6. The degradable ventricular septal defect occluder of claim 2, wherein the second cap has a positioning hole in the center for adjusting the position of the constriction on the disk.

7. The degradable ventricular septal defect occluder of claim 2, wherein the first cap and/or the second cap snap-fits to the peripheral component.

8. The degradable ventricular septal defect occluder of claim 2, wherein the peripheral component comprises two semicircular portions spliced together.

9. The degradable ventricular septal defect occluder of claim 1, wherein the dedicated mold further comprises a housing, a plurality of heating tubes are inserted into the wall surface of the housing, and a cooling pipeline is further arranged in the wall surface of the housing;

the core die is accommodated in the inner cavity of the shell;

10. A method of manufacturing a degradable ventricular septal defect occluder, comprising: a main body component, a flow impeding component, and a suture; the main body component comprises a net body and a connecting piece connected to the net body, the net body comprises a first disc-shaped part, a tubular part and a second disc-shaped part which are sequentially connected, the first disc-shaped part and the second disc-shaped part are both double-layer net surfaces, and two ends of the tubular part are respectively connected to the first disc-shaped part and the second disc-shaped part; wherein the flow resisting part is at least two layers of degradable films or non-degradable films for resisting the blood flow; wherein the suture is a degradable suture or a non-degradable suture for sewing the flow resisting part on the main body part and serving as a closing line;

the manufacturing method comprises the following steps:

shaping the tubular net body at 35-200 deg.C for 1-60 min;

wherein the content of the first and second substances,

the special mold comprises a core mold;

the first cover body covers the first opening of the outer peripheral component in the axial direction, the second cover body covers the second opening of the outer peripheral component in the axial direction, the central component is arranged in the outer peripheral component, an intermediate annular gap is formed between the outer peripheral wall of the central component and the inner peripheral wall of the outer peripheral component and used for forming the tubular part, a first step surface extending towards the outer peripheral direction is arranged on the part, close to the first opening, of the inner peripheral wall of the outer peripheral component, a first annular gap is formed between the first step surface and the inner side surface of the first cover body and used for forming the first disc-shaped part, a second step surface extending towards the outer peripheral direction is arranged on the part, close to the second opening, of the inner peripheral wall of the outer peripheral component, and a second annular gap is formed between the second step surface and the inner side surface of the second cover body, the second annular void is for forming the second disc; and vent holes are formed in the first cover body and the second cover body.