A biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets

Abstract

This invention relates to a biodegradable cardiac occluder for bilateral patent ductus arteriosus (PDA) without rivets. The occluder includes a main body, a flow-blocking component, sutures, and a rivetless flat-face connector. The main body has a mesh structure, comprising a frustum, a disc, and a recess. The sutures connect the flow-blocking component to the main body. The rivetless flat-face connector includes a delivery disc and threaded holes. The delivery disc also has mesh fixing holes that connect the recess to the delivery disc. The occluder can be directly threaded to a delivery device such as a steel cable via the threaded holes and the delivery disc, thus delivering it to the heart. This invention uses a small disc instead of rivets, achieving both re-delivery and reducing the incidence of thrombosis due to the rivetless design. The rivetless flat-face connector is biodegradable. During processing, it is woven into the mesh, making it convenient, safe, and quick.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a bilateral rivetless patent ductus arteriosus degradable cardiac occluder. Background Technology

[0002] Patent ductus arteriosus (PDA) is a common congenital heart disease, referring to a congenital abnormal passage between the aorta and the pulmonary artery, usually located between the aortic isthmus and the root of the left pulmonary artery. PDA primarily develops during fetal growth and development, due to factors affecting heart development. In patients with PDA, blood normally flows from the aorta through the PDA into the pulmonary artery, then returns to the left atrium and left ventricle. This can cause hypertrophy and enlargement of the left atrium and left ventricle, ultimately leading to left ventricular failure. If the ductus arteriosus has a larger diameter, it can also lead to right ventricular hypertrophy and dynamic pulmonary hypertension.

[0003] Patent ductus arteriosus (PDA) is a common congenital heart disease, and the traditional treatment is surgery. Surgical treatment requires open-chest surgery, and its biggest disadvantages are: (1) cardiopulmonary bypass is required during the operation, and the operation may cause complications leading to death; (2) the surgery is highly invasive and leaves scars after the operation; (3) the surgery is expensive; (4) the risk of PDA surgery increases in adults and when the diameter of the artery is large.

[0004] Since the 1980s, with the development and improvement of catheter-based interventional diagnostic and therapeutic techniques, my country has gradually introduced minimally invasive interventional techniques to treat congenital heart disease. The method of treating patent ductus arteriosus (PDA) through minimally invasive intervention has developed rapidly and is now very mature. Compared with traditional surgery, minimally invasive intervention is a modern, high-tech, and minimally invasive treatment. Through femoral vein puncture, guided by medical imaging equipment, a guide wire is inserted along the femoral vein, inferior vena cava, and into the right ventricle, passing through the pulmonary artery, and through the PDA to enter the aorta. The delivery catheter is then placed along the guide wire at the PDA site, and finally, a PDA occluder is pushed into the delivery catheter to perform the occlusion treatment. This minimally invasive intervention has advantages such as no incision, minimal trauma, fewer complications, rapid recovery, good efficacy, a wide range of indications, and relatively low surgical costs.

[0005] Although the treatment method of implanting a patent ductus arteriosus occluder through minimally invasive interventional surgery has many advantages over traditional surgery, the main material of the main stent of the patent ductus arteriosus occluder currently used in clinical practice is nickel-titanium alloy wire. Since this type of metal material is non-degradable, long-term implantation may cause inflammation, coagulation and other reactions with human tissues, or even a certain degree of damage. Therefore, it has certain defects and may still have the following risks: (1) Nickel-titanium alloy is a non-degradable metal alloy material. Although its biocompatibility has been demonstrated, the long-term risks of long-term permanent implantation cannot be completely controlled; (2) Since nickel-titanium alloy is permanently implanted and non-degradable, there is a lack of long-term follow-up data on the safety of permanent retention in the heart and the impact of a fixed-size heart occluder on the continuously growing and developing heart of children. It may affect the development and growth of the heart of patients who have not yet reached maturity; (3) Complications such as nickel precipitation and nickel allergy have not yet been clearly demonstrated by science.

[0006] Once the surface of the cardiac occluder is completely endothelialized and the heart defect is repaired by the body's own tissues, there is absolutely no need for the cardiac occluder to remain in the body. Therefore, an ideal cardiac occluder should provide a temporary bridge for the heart's self-repair, be degraded by the body after fulfilling its purpose, and allow the defect to be completely repaired by the body's own tissues, thereby avoiding the long-term complications and safety hazards caused by metal remaining in the body.

[0007] Chinese patent application CN202110138185.2 discloses a biodegradable patent ductus arteriosus (PDA) occluder and its manufacturing method. The biodegradable PDA occluder includes a main body, a flow-blocking component, and a suture. The biodegradable PDA occluder is made using a special mold. The special mold includes a core mold. The core mold includes a first cover, a second cover, a central component, and an annular peripheral component. The first cover covers a first axial opening of the peripheral component, and the second cover covers a second axial opening of the peripheral component. The central component is located inside the peripheral component, and a first annular gap is formed between the outer peripheral wall of the central component and the inner peripheral wall of the peripheral component. This first annular gap forms a frustum. A stepped surface extending outwards is also provided on the inner peripheral wall of the peripheral component near the second opening. A second annular gap is formed between the stepped surface and the inner surface of the second cover, and this second annular gap forms a disc-shaped portion. However, we can see that the occluder includes a connector, a structure that can lead to thrombus formation during endothelialization.

[0008] Chinese patent application CN202110139682.4 discloses a patent ductus arteriosus (PDA) occluder with flat end faces and its manufacturing method. The PDA occluder includes a main body, a flow-blocking component, and a suture. The main body has a mesh structure and includes a frustum and a disc-shaped portion connected to one end of the frustum and protruding outwards circumferentially along the frustum. The flow-blocking component is a biodegradable or non-biodegradable membrane with at least two layers for blocking blood flow. After being closed with a suture, both the end of the disc-shaped portion away from the frustum and the end of the frustum away from the disc-shaped portion have continuous flat mesh surfaces. The PDA occluder is made using a dedicated mold. The dedicated mold includes a core mold, which includes a first cover, a central component, a second cover, and an annular outer peripheral component. The dedicated mold method is simple, quick, and cost-effective. The flat end faces facilitate faster endothelialization of the occluder surface, allowing for earlier repair of the PDA by the occluder's own tissue. However, this occluder cannot be directly connected to a delivery device such as a steel cable to deliver the occluder to the heart.

[0009] The present invention is to truly achieve a biodegradable occluder structure with no rivets on both sides, thereby solving the problem of thrombus formation during endothelialization. There are currently no reports on a biodegradable cardiac occluder for patent ductus arteriosus with no rivets on both sides. Summary of the Invention

[0010] The purpose of this invention is to address the long-term risks associated with existing clinical use of patent ductus arteriosus (PDA) and to overcome the shortcomings of high cost and poor self-expansion recovery of existing technologies. This invention provides a bilateral, rivetless, biodegradable cardiac occluder for PDA.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0012] This invention provides a biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets. The occluder includes a main body, a flow-blocking component, a suture, and a rivetless flat end face connector 4. The main body is a mesh structure, which includes a disc-shaped portion 1, a recessed portion 2, and a frustum-shaped portion 3. The suture connects the main body and the flow-blocking component, and the frustum-shaped portion 3 connects the disc-shaped portion 1 and the recessed portion 2. The rivetless flat end face connector 4 includes a delivery disc 10 and a threaded hole 9. The delivery disc 10 is also provided with a mesh fixing hole 11, and the delivery disc 10 is connected to the recessed portion 2 through the mesh fixing hole 11.

[0013] Furthermore, the recessed portion 2 constitutes the upper disk surface 6 of the plug, and the disc-shaped portion 1 constitutes the lower disk surface 5 of the plug.

[0014] Furthermore, it also includes steel cable 7.

[0015] Furthermore, the steel cable 7 includes a thread 8.

[0016] Furthermore, the steel cable 7 is connected via thread 8 and threaded hole 9.

[0017] Furthermore, the connection between the frustum portion 3 and the disc portion 1 is as follows: one end of the frustum portion 3 protrudes outward along the circumference of the frustum portion 3 to form the disc portion 1, and the end of the disc portion 1 away from the frustum portion 3 and the end of the frustum portion 3 away from the disc portion 1 are both continuous and flat mesh surfaces.

[0018] Furthermore, the recessed portion 2 is located at the constricted end of the outer mesh surface of the frustum portion 3.

[0019] Furthermore, the flow-blocking component is a biodegradable membrane of at least two layers used to block blood flow.

[0020] Furthermore, the conveyor tray 10 is made of a biodegradable material.

[0021] Furthermore, the biodegradable material or biodegradable filament is a biodegradable polymer material, which is selected from one or more of polylactide, polyglycolic acid, polycaprolactone, polydioxanone, polyhydroxybutyrate, polyhydroxy fatty acid ester, polyanhydride, polyphosphate, polyurethane or polycarbonate, and their derivatives.

[0022] The advantages of this invention are:

[0023] 1. Currently, most sealing devices on the market are either double-riveted or single-riveted. This invention, to achieve a double-sided rivetless effect, replaces the riveted side with a biodegradable disc structure. The disc surface has threaded holes, which facilitates the connection for delivery. The double-sided rivetless design offers the following advantages:

[0024] (1) From a physical perspective, the rivet head is not easily broken;

[0025] (2) In terms of chemistry, there is no thermal fusion riveting process, and the material structure is stable;

[0026] (3) In terms of materials, reduce the proportion of foreign bodies in the patient's body;

[0027] (4) During the release process, reduce the surgical risk caused by the unscrewing of the thread causing the already determined position of the plug to change;

[0028] (5) The rivetless occluder shortens the time to complete endothelialization, reduces the period of use of anticoagulant drugs for patients, avoids other complications caused by coagulation, and can effectively shorten the recovery time of patients.

[0029] Meanwhile, rivetless occluders can effectively reduce the incidence of thrombosis with single / double rivet occluders.

[0030] 2. This invention makes further improvements based on the original research. The improved occluder eliminates the protruding connecting parts, adds a delivery disc, and designs a threaded hole. During use, the threads of delivery devices such as steel cables can be directly connected to the threaded hole of the occluder to complete the delivery of the occluder. Compared with the occluders in the prior art, it reduces the structure, avoids long-term complications and safety hazards, and can be directly connected to delivery devices such as steel cables to complete the delivery of the occluder. It is convenient to use, highly practical, and has good therapeutic effect. Attached Figure Description

[0031] Appendix Figure 1 This is a schematic diagram of the overall structure of the biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets according to the present invention.

[0032] Appendix Figure 2 This is a front structural schematic diagram of the biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets according to the present invention.

[0033] Appendix Figure 3 This is a side view of the biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets according to the present invention.

[0034] Appendix Figure 4 This is a schematic diagram of the sealing device and steel cable.

[0035] Appendix Figure 5 This is a schematic diagram of the conveyor tray.

[0036] Appendix Figure 6 This is a schematic diagram showing the connection between the plug and the steel cable (transmission device).

[0037] Appendix Figure 7 This is a schematic diagram of the existing patent ductus arteriosus occluder structure.

[0038] 1. Discoid part;

[0039] 2. Depression;

[0040] 3. Frustum section;

[0041] 4. Rivetless flat end face connector;

[0042] 5. Lower plate;

[0043] 6. Top plate;

[0044] 7. Steel cable;

[0045] 8. Thread;

[0046] 9. Threaded hole;

[0047] 10. Conveyor tray;

[0048] 11. Mesh fixing holes. Detailed Implementation

[0049] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0050] Example 1

[0051] Please refer to Figure 7 , attached Figure 7 This is a schematic diagram of the existing patent ductus arteriosus occluder structure.

[0052] from Figure 7 It can be seen that the existing sealing devices include protruding connectors.

[0053] This embodiment is a further improvement based on the existing technology. Please refer to [link / reference]. Figure 1-3 , attached Figure 1 This is a schematic diagram of the overall structure of the biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets of the present invention. Figure 2 This is a front structural schematic diagram of the biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets of the present invention, attached. Figure 3 This is a side view of the biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets according to the present invention.

[0054] This embodiment provides a biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets. The occluder includes a main body, a flow-blocking component, a suture, and a rivetless flat-face connector 4. The main body has a mesh structure, which includes a disc-shaped portion 1, a recessed portion 2, and a frustum-shaped portion 3. The suture connects the main body and the flow-blocking component, and the frustum-shaped portion 3 connects the disc-shaped portion 1 and the recessed portion 2. The rivetless flat-face connector 4 includes a delivery disc 10 and a threaded hole 9. The delivery disc 10 also has a mesh fixing hole 11, which connects the delivery disc 10 to the recessed portion 2. The recessed portion 2 forms the upper disc surface 6 of the occluder, and the disc-shaped portion 1 forms the lower disc surface 5 of the occluder (see...). Figure 3Further, it also includes a steel cable 7, which includes a thread 8 and is connected through a threaded hole 9 in the thread 8. Further, the connection between the frustum portion 3 and the disc-shaped portion 1 is as follows: one end of the frustum portion 3 protrudes outward along its circumference to form the disc-shaped portion 1, and both the end of the disc-shaped portion 1 away from the frustum portion 3 and the end of the frustum portion 3 away from the disc-shaped portion 1 are continuous, flat mesh surfaces. Further, the recessed portion 2 is located at the constricted end of the outer mesh surface of the frustum portion 3. Further, the flow-blocking component is a biodegradable membrane of at least two layers used to block blood flow. Further, the delivery disc 10 is made of a biodegradable material. Furthermore, the biodegradable material or biodegradable filament is a biodegradable polymer material, which is selected from one or more of polylactide, polyglycolic acid, polycaprolactone, polydioxanone, polyhydroxybutyrate, polyhydroxy fatty acid ester, polyanhydride, polyphosphate, polyurethane or polycarbonate, and their derivatives.

[0055] The usage method and working principle of this embodiment are as follows:

[0056] First, the disc-shaped part 1 and the recessed part 2 are connected by the frustum part 3 (this preparation method (or connection method) is already in the prior art, so it will not be described in detail here). Then, the conveying disc 10 is connected to the recessed part 2 by the mesh fixing hole 11 (that is, the conveying disc 10 is woven in the recessed part 2). Next, the steel cable 7 is connected to the plugging device by the thread 8 and threaded hole 9 of the steel cable 7, thereby conveying the multi-layer plugging device. After that, the subsequent operations can be completed according to the conventional method.

[0057] It should be noted that some existing occluders have an additional protruding connector (see...). Figure 7 This invention utilizes a connector to connect with a delivery device such as a steel cable to deliver the occluder. However, the protruding connector hinders the endothelialization process on the disc surface, resulting in a slower endothelialization process at the protruding connector, affecting the healing process after occluder implantation and increasing healing time. Furthermore, the protruding connectors at both ends increase the length of the occluder release, potentially touching nearby cardiac tissue and causing cardiac injury. Moreover, some existing rivetless occluders lack threads, making it impossible for existing steel cables to directly connect to and deliver the occluder, necessitating a redesigned delivery device. This invention overcomes these shortcomings by designing a delivery disc and threaded holes, allowing direct connection of the occluder to the steel cable or other delivery device for delivery to the heart. Furthermore, this invention eliminates the connector, avoiding secondary harm to the human body. Thus, this invention simultaneously achieves the goals of rivetless delivery and efficient delivery. Additionally, this invention uses biodegradable materials, preventing long-term harm to the human body from the materials' presence.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the principle of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A biodegradable cardiac occluder for bilateral patent ductus arteriosus without rivets, characterized in that, The plugging device includes a main body component, a flow-blocking component, a suture line, and a rivetless flat end face connector (4). The main body component is a mesh structure, which includes a disc-shaped part (1), a recessed part (2), and a frustum part (3). The suture line connects the main body component and the flow-blocking component. The frustum part (3) connects the disc-shaped part (1) and the recessed part (2). The recessed part (2) is located at the closing end of the outer mesh surface of the frustum part (3). The rivetless flat end face connector (4) includes a conveying disc (10) and a threaded hole (9). The conveying disc (10) is also provided with a mesh fixing hole (11). The conveying disc (10) is connected to the recessed part (2) through the mesh fixing hole (11). The connection between the frustum portion (3) and the disc portion (1) is as follows: one end of the frustum portion (3) protrudes outward along the circumference of the frustum portion (3) to form the disc portion (1). The end of the disc portion (1) away from the frustum portion (3) and the end of the frustum portion (3) away from the disc portion (1) are both continuous and flat mesh surfaces.

2. The occluder according to claim 1, characterized in that, The recessed portion (2) forms the upper plate surface (6) of the plug, and the disc-shaped portion (1) forms the lower plate surface (5) of the plug.

3. The occluder according to claim 1, characterized in that, It also includes steel cables (7).

4. The occluder according to claim 3, characterized in that, The steel cable (7) includes a thread (8).

5. The plugging device according to claim 4, characterized in that, The steel cable (7) is connected to the threaded hole (9) via a thread (8).

6. The occluder according to claim 1, characterized in that, The flow-blocking component is a biodegradable membrane of at least two layers used to block blood flow.

7. The plugging device according to claim 1, characterized in that, The conveyor tray (10) is made of biodegradable material.

8. The plugging device according to claim 6 or 7, characterized in that, The biodegradable material or biodegradable membrane is a biodegradable polymer material, wherein the biodegradable polymer material is selected from one or more of polylactide, polyglycolic acid, polycaprolactone, polydioxanone, polyhydroxybutyrate, polyhydroxy fatty acid ester, polyanhydride, polyphosphate, polyurethane or polycarbonate, and their derivatives.

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