A biodegradable cardiac occluder for bilateral rivetless atrial septal defects

Abstract

This invention relates to a biodegradable cardiac occluder for bilateral rivetless atrial septal defects. The occluder includes a main body, a flow-blocking component, sutures, and a rivetless flat-face connector. The main body is a mesh structure comprising a first disc-shaped portion, a second disc-shaped portion, and a tubular portion. The flow-blocking component is a biodegradable membrane with at least two layers for blocking blood flow. The sutures are biodegradable sutures used to sew the flow-blocking component onto the main body and also serve as a closing suture. The rivetless flat-face connector includes a threaded hole and a delivery disc. This invention uses a small disc instead of rivets, achieving both re-delivery and the goal of reducing thrombosis incidence through 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 biodegradable cardiac occluder for bilateral rivetless atrial septal defects. Background Technology

[0002] Atrial septal defect (ASD) is a common type of congenital heart disease. The human heart consists of four chambers: the left atrium, left ventricle, right atrium, and right ventricle. The upper left and right atria should normally be separated by a complete atrial septum. If there is an opening in this septum, it is called an ASD. ASDs primarily develop during fetal growth and development, due to factors affecting heart development. In patients with ASDs, blood typically flows from the left atrium into the right atrium through the ASD, increasing the blood volume in the right atrium. The long-term presence of an ASD can cause pulmonary hypertension, congestive heart failure, arrhythmias, stroke, dizziness, and syncope.

[0003] Atrial septal defect (ASD) is a common congenital heart disease, and the traditional treatment is surgery. Surgical treatment requires open-chest surgery, which has several drawbacks: (1) cardiopulmonary bypass is required during the procedure, and complications may lead to death; (2) the surgery is highly invasive, leaving scars; and (3) the procedure is expensive. 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. Minimally invasive interventional treatment of ASD has developed rapidly and is now very mature. Compared to traditional surgery, minimally invasive interventional treatment is a modern, high-tech, minimally invasive treatment. Through femoral vein puncture, under the guidance of medical imaging equipment, a guide wire is inserted along the femoral vein and inferior vena cava until it enters the right atrium, passes through the ASD, and enters the left atrium. The delivery catheter is then placed along the guide wire at the ASD site, and finally, the ASD occluder is pushed into the delivery catheter to the ASD site for occlusion treatment. Such minimally invasive interventional treatment has advantages such as no surgery, minimal trauma, fewer complications, faster recovery, better results, a wide range of indications, and relatively lower surgical costs.

[0004] While minimally invasive interventional surgery for atrial septal defect occluders offers many advantages over traditional surgery, the main structure of currently used occluders has protruding connection points at both ends. This protruding structure hinders the endothelialization process on the disc surface, resulting in slower endothelialization at the protruding connection points. This affects the healing process after occluder implantation, thus increasing healing time. Furthermore, the protruding connection points at both ends increase the length of the occluder release, potentially touching nearby cardiac tissue and causing cardiac injury.

[0005] The present invention aims to solve the problem of thrombus formation during endothelialization by achieving a truly biodegradable occluder structure with no rivets on both sides.

[0006] Chinese patent application 202011619417.8 discloses a patent foramen ovale (PFO) occluder with flat end faces and its manufacturing method. The PFO occluder includes a main body, a flow-blocking component, and a suture. The main body has a mesh structure and includes a first disc-shaped portion, a tubular portion, and a second disc-shaped portion connected in sequence. The two ends of the tubular portion are respectively connected to the centers of the first and second disc-shaped portions. 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, the outer mesh surfaces of the first and second disc-shaped portions are both continuous and flat mesh surfaces. The PFO occluder is made by a special mold. The special mold includes a core mold, which includes a first cover, a central component, a second cover, and a central column. The special mold method is simple, quick, and cost-effective. The flat end faces facilitate the acceleration of endothelialization on the surface of the occluder, allowing the PFO to be repaired by its own tissue earlier. However, this occluder requires a special device to deliver it to the heart during use.

[0007] Chinese patent application 202011619405.5 discloses a biodegradable patent foramen ovale (PFO) occluder and its manufacturing method. This biodegradable PFO occluder is made of biodegradable filament and includes: a main body, a flow-blocking component, and sutures; the main body includes a mesh and connectors, the mesh comprising a first disc-shaped portion, a tubular portion, and a second disc-shaped portion connected sequentially, with both ends of the tubular portion connected to the centers of the first and second disc-shaped portions respectively; the flow-blocking component is at least two layers of biodegradable or non-biodegradable membrane for blocking blood flow; the PFO occluder is manufactured using a dedicated mold; the dedicated mold includes a core mold; the core mold includes: a first cover, a central component, a second cover, and a central column. Using a dedicated mold to shape the PFO occluder is simple, quick, and low-cost. However, the occluder also includes connectors. These protruding structures hinder the endothelialization process on the disc surface, and the endothelialization process is relatively slow at the protruding connector points. This affects the healing process at these points after occluder implantation, thus increasing healing time. Furthermore, the protruding connectors on both ends increase the length of the occluder release, potentially touching nearby cardiac tissue and causing cardiac damage.

[0008] Therefore, in order to overcome the shortcomings of the existing technology, this invention creatively proposes a new type of occluder. There are currently no reports on a bilateral rivetless biodegradable cardiac occluder for atrial septal defects. Summary of the Invention

[0009] The purpose of this invention is to address the long-term risks associated with existing atrial septal defect occluders used in clinical practice, and to overcome the shortcomings of existing technologies, such as high cost, slow endothelialization of the occluder surface due to protruding connection points on both ends of the occluder, and long release length of the occluder. The invention provides a cardiac atrial septal defect occluder with flat ends.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] This invention provides a biodegradable cardiac occluder for bilateral rivetless atrial septal defects. The occluder includes a main body, a flow-blocking component, a suture, and a rivetless flat end face connector 3. The main body consists of a mesh structure and a tubular portion 11. The mesh structure includes a first disc-shaped portion 1 and a second disc-shaped portion 2. The suture connects the flow-blocking component to the main body. The rivetless flat end face connector 3 includes a threaded hole 6 and a delivery disc 10. The delivery disc 10 has a mesh fixing hole 9 on its surface. The tubular portion 11 connects the first disc-shaped portion 1 and the second disc-shaped portion 2. The mesh of the second disc-shaped portion 2 is connected to the delivery disc 10 through the mesh fixing hole 9. The second disc-shaped portion 2 and the delivery disc 10 have a threaded hole 6 at their center.

[0012] Furthermore, the upper surface of the second disc-shaped portion 2 is the upper disc surface 4, and the lower surface of the first disc-shaped portion 1 is the lower disc surface 5. Both the upper disc surface 4 and the lower disc surface 5 are flat mesh surfaces.

[0013] Furthermore, the plugging device also includes a steel cable 7.

[0014] Furthermore, one end of the steel cable 7 is provided with a thread 8.

[0015] Furthermore, the steel cable 7 is connected to the threaded hole 6 via a thread 8.

[0016] Furthermore, the main body component is woven from biodegradable filaments.

[0017] Furthermore, the flow-blocking component is a biodegradable membrane of at least two layers used to block blood flow; wherein the suture is a biodegradable suture used to sew the flow-blocking component onto the main body component and to close the opening.

[0018] Furthermore, the conveyor plate 10 is made of a biodegradable material.

[0019] Furthermore, the biodegradable material or biodegradable filament is a biodegradable polymer material.

[0020] Furthermore, 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.

[0021] Biodegradable sutures are made of biodegradable materials, selected from polyethylene propylene, polylactide, etc.

[0022] Furthermore, the rivetless flat end face connector is made of a biodegradable polymer material selected from polylactide, polyglycolic acid, polycaprolactone, polydioxanone, polyhydroxybutyrate, polyhydroxy fatty acid ester, polyanhydride, polyphosphate, polyurethane or polycarbonate, and their derivatives, blends of two or more, or copolymers of the corresponding monomers.

[0023] The advantages of this invention are:

[0024] 1. Currently, most rivets on the market are either double-rivet or single-rivet. To achieve a rivetless effect on both sides, this invention replaces the riveted side with a biodegradable disc structure. The disc surface has threaded holes, which facilitates the connection during transport. The rivetless design on both sides offers the following advantages:

[0025] (1) From a physical perspective, the rivet head is not easily broken;

[0026] (2) In terms of chemistry, there is no thermal fusion riveting process, and the material structure is stable;

[0027] (3) In terms of materials, reduce the proportion of foreign bodies in the patient's body;

[0028] (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;

[0029] (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.

[0030] Meanwhile, rivetless occluders can effectively reduce the incidence of thrombosis with single / double rivet occluders.

[0031] 2. The delivery disc and threaded hole added in this invention can be directly connected to the steel cable, thereby realizing the delivery of the occluder to the heart. This overcomes the defect of the prior art which requires an additional structure to deliver the occluder to the heart. The structure is simple, the cost is reduced, and it is easy to use and avoids the occurrence of complications in the prior art. It is highly practical and has a good application prospect. Attached Figure Description

[0032] Appendix Figure 1 This is a schematic diagram of the structure of the plugging device of the present invention.

[0033] Appendix Figure 2 This is a side view of the occluder of the present invention.

[0034] Appendix Figure 3 yes Figure 1 A magnified structural diagram of the central part.

[0035] Appendix Figure 4 This is a schematic diagram of the sealing device and conveying device of the present invention.

[0036] Appendix Figure 5 This is a schematic diagram showing the connection between the sealing device and the conveying device of the present invention.

[0037] Appendix Figure 6 This is a schematic diagram of the conveyor disc and the mesh fixing hole structure of the present invention.

[0038] Appendix Figure 7 This is a schematic diagram of the longitudinal section structure of the plugging device of the present invention.

[0039] Appendix Figure 8 This is a schematic diagram of the structure of an existing plugging device.

[0040] 1. First discoid part;

[0041] 2. Second disc-shaped portion;

[0042] 3. Rivetless flat end face connector;

[0043] 4. Top plate;

[0044] 5. Lower plate;

[0045] 6. Threaded hole;

[0046] 7. Steel cable;

[0047] 8. Thread;

[0048] 9. Mesh fixing holes;

[0049] 10. Conveyor tray;

[0050] 11. Tubular part. Detailed Implementation

[0051] 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.

[0052] Example 1

[0053] Please refer to Figure 8 , attached Figure 8 This is a schematic diagram of the structure of an existing plugging device.

[0054] Please refer to Figure 6-7 , attached Figure 6 This is a schematic diagram of the conveyor tray and the mesh fixing hole structure of the present invention. (Attached) Figure 7 This is a schematic diagram of the longitudinal section structure of the plugging device of the present invention.

[0055] The bilateral rivetless biodegradable cardiac occluder for atrial septal defects of the present invention includes a main body component, a flow-blocking component, a suture, and a rivetless flat end face connector 3. The main body component is a mesh structure and a tubular portion 11. The mesh structure includes a first disc-shaped portion 1 and a second disc-shaped portion 2 (see...). Figure 7 The stitching connects the flow-blocking component to the main component. The rivetless flat end face connector 3 includes a threaded hole 6 and a conveyor disc 10. The surface of the conveyor disc 10 is provided with mesh fixing holes 9 (see...). Figure 6 The tubular portion 11 connects the first disc-shaped portion 1 and the second disc-shaped portion 2. The mesh of the second disc-shaped portion 2 is connected to the conveyor plate 10 through the mesh fixing hole 9. The second disc-shaped portion 2 and the conveyor plate 10 are provided with threaded holes 6 at their centers (see...). Figure 6-7 The upper surface of the second disc-shaped portion 2 is the upper disc surface 4, and the lower surface of the first disc-shaped portion 1 is the lower disc surface 5. Both the upper disc surface 4 and the lower disc surface 5 are flat mesh surfaces. The occluder also includes a steel cable 7. One end of the steel cable 7 is provided with a thread 8. The steel cable 7 is connected to the threaded hole 6 through the thread 8. The main body component is woven from biodegradable filaments. The flow-blocking component is a biodegradable membrane of at least two layers used to block blood flow; wherein, the suture is a biodegradable suture used to sew the flow-blocking component onto the main body component and as a closing suture. The delivery disc 10 is made of a biodegradable material. The biodegradable material or biodegradable filament is a biodegradable polymer material. The biodegradable polymer material is selected from one or more of polylactide, polyglycolic acid, polycaprolactone, polydioxanone, polyhydroxybutyrate, polyhydroxyalkanoates, polyanhydrides, polyphosphates, polyurethanes or polycarbonates, and their derivatives. The biodegradable suture is made of biodegradable material, selected from polyethylene propylene glycol, polylactide, etc. The rivetless flat-end connector is made of biodegradable polymer material, selected from polylactide, polyethylene glycol, polycaprolactone, polydioxanone, polyhydroxybutyrate, polyhydroxyalkanoates, polyanhydrides, polyphosphates, polyurethanes or polycarbonates, and their derivatives, blends of two or more of them, or copolymers of the corresponding monomers.

[0056] The usage method and working principle of this embodiment are as follows:

[0057] First, the mesh of the second disc-shaped part 2 is fixed to the conveyor plate 10 through the mesh fixing hole 9 on the surface of the conveyor plate 10. Then, the first disc-shaped part 1 and the second disc-shaped part 2 are connected through the tubular part 11. Next, the thread 8 of the steel cable 7 is connected to the threaded hole 6, thereby connecting the steel cable 7 to the second disc-shaped part 2. Finally, the occluder is directly delivered to the heart using the steel cable 7 to complete the subsequent operation.

[0058] It should be noted that some existing technologies use additionally designed protruding connectors (see...). Figure 8 The present invention uses threaded holes and a delivery disc to directly connect to the steel cable and deliver the occluder into the heart, avoiding the problems associated with protruding structures that hinder endothelialization of the disc surface. The endothelialization process at the protruding connector is relatively slow, affecting the healing process after implantation and increasing healing time. Furthermore, the protruding connectors at both ends increase the length of the occluder release, potentially touching nearby heart tissue and causing cardiac injury. Existing rivetless occluders lack threads, making it impossible to connect and deliver with existing steel cables, requiring a redesigned delivery device. The present invention innovatively adds threaded holes to the occluder, allowing connection to conventional steel cables and delivery devices while achieving both rivetless and delivery capabilities. Moreover, the structure of the present invention uses biodegradable materials, avoiding secondary harm to the human body from long-term contact with the device.

[0059] The occluder of this invention has a simpler structure, is easier to use, is more practical, and has broad application prospects.

[0060] 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 rivetless atrial septal defects, 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 (3). The main body component consists of a mesh structure and a tubular part (11). The mesh structure includes a first disc-shaped part (1) and a second disc-shaped part (2). The diameter of the first disc-shaped part (1) is larger than that of the second disc-shaped part (2). The suture line connects the flow-blocking component to the main body component. The rivetless flat end face connector (3) includes a threaded hole (6) and a conveying disc (10). The surface of the conveying disc (10) is provided with a woven mesh. Fixed hole (9), the tubular part (11) connects the first disc part (1) and the second disc part (2), the mesh of the second disc part (2) is connected to the conveying plate (10) through the mesh fixing hole (9), and the second disc part (2) and the conveying plate (10) are provided with threaded holes (6) at the center; the flow blocking component is a biodegradable membrane of at least two layers for blocking blood flow; wherein, the suture is a biodegradable suture for sewing the flow blocking component onto the main body and as a closing line; The upper surface of the second disc-shaped part (2) is the upper disc surface (4), and the lower surface of the first disc-shaped part (1) is the lower disc surface (5). Both the upper disc surface (4) and the lower disc surface (5) are flat mesh surfaces.

2. The occluder according to claim 1, characterized in that, The plugging device also includes a steel cable (7).

3. The occluder according to claim 2, characterized in that, One end of the steel cable (7) is provided with a thread (8).

4. The occluder according to claim 3, characterized in that, The steel cable (7) is connected to the threaded hole (6) via a thread (8).

5. The plugging device according to claim 1, characterized in that, The main component is woven from biodegradable yarn.

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

7. The plugging device according to claim 5, characterized in that, The biodegradable filament is a biodegradable polymer material.

8. The occluder according to claim 6, characterized in that, The biodegradable material is a biodegradable polymer.

9. The plugging device according to any one of claims 7-8, characterized in that, 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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