A fully degradable left atrial appendage occluder

Abstract

The present invention relates to a completely degradable left atrial appendage occluder, which belongs to the technical field of medical devices. It comprises a fixing disk and a covering disk; a fixing disk is provided at one end of the occluder close to the bottom of the left atrial appendage, and a covering disk is provided at the other end; a connecting rivet is provided on the side of the covering disk close to the opening of the left atrial appendage; the occluder is made of completely biodegradable materials. After the left atrial appendage occluder provided by the present invention is implanted into the body, it becomes a bridge for endothelial cells to climb. After a period of implantation, the surface of the left atrial appendage occluder is covered by new endothelial tissue, thereby achieving self-occlusion of the left atrial appendage. The occluder is eventually degraded by the body, so that the left atrial appendage is completely filled with its own tissue, avoiding long-term complications and safety hazards caused by metal retention in the body.

Description

Technical Field

[0001] The present invention relates to a fully degradable left atrial appendage occluder, belonging to the technical field of medical devices. Background Art

[0002] The left atrial appendage (LAA), located in the inner corner of the left atrium, is a blood trap. Patients with atrial fibrillation (AF) are primarily at risk. When atrial contraction pressure decreases in AF, blood flow within the LAA slows, making it more susceptible to clotting and forming a thrombus. If a thrombus breaks free, it can travel through the bloodstream to the intracranial vessels, blocking small brain vessels and causing an ischemic stroke. 17% of patients with AF develop thrombi, and approximately 91% of these thrombi originate in the LAA. Strokes caused by AF are characterized by high disability, high mortality, and high recurrence rates. Therefore, the importance of stroke risk control and thrombus management in patients with AF has become widely recognized. LAA closure can reduce the risk of stroke in patients with AF to a certain extent.

[0003] Currently, the main interventions for preventing ischemic stroke caused by the left atrial appendage (LAA) are percutaneous LAA occlusion and surgical LAA resection or closure. Percutaneous LAA occlusion is a recently developed treatment method that is less invasive, simple to perform, and less time-consuming. This treatment involves percutaneously puncturing the femoral vein, traversing the atrial septum, and placing an LAA occluder at the LAA opening. This isolates the left atrium from the LAA lumen, thereby preventing stroke caused by detached LAA thrombus. Clinical studies have confirmed the safety and effectiveness of this technique in preventing thromboembolic events in atrial fibrillation.

[0004] Currently, the materials used for left atrial appendage occluders are all nickel-titanium alloys. Congenital heart disease occluders made of nickel-titanium alloys have been used for decades at home and abroad and have shown good short- and medium-term therapeutic effects. However, the complications caused by metal materials cannot be ignored, including wear of surrounding tissue structures by metal occluders, galvanic corrosion, allergic reactions caused by metal ion precipitation, nuclear magnetic resonance limitations, psychological impact factors caused by lifelong retention of metal stents in the body, etc. Moreover, there is a lack of data to support the long-term safety of metals in the human body due to lifelong retention of metals in the body.

[0005] After implantation, the LAA occluder becomes a bridge for endothelial cells to climb. After a period of time, the surface of the LAA occluder is covered by newly formed endothelial tissue, effectively sealing the LAA itself. At this point, the LAA occluder has completed its mission and is no longer needed in the body. Therefore, an ideal LAA occluder should provide a temporary "bridge" for the LAA to achieve self-closure. After completing its "historical mission," the "bridge" is degraded by the body, allowing the defect to be completely repaired by the body's own tissue, avoiding the long-term complications and safety risks associated with metal retention in the body. Summary of the Invention

[0006] The purpose of the present invention is to solve the technical problem of how to achieve self-occlusion of the left atrial appendage and avoid long-term complications and safety hazards caused by metal residues in the body.

[0007] In order to achieve the purpose of solving the above-mentioned problems, the technical solution adopted by the present invention is to provide a fully degradable left atrial appendage occluder; comprising a fixing plate and a covering plate; a fixing plate is provided at one end of the occluder close to the bottom of the left atrial appendage, and a covering plate is provided at the other end; a connecting rivet is provided on the side of the covering plate close to the opening of the left atrial appendage; the occluder is made of fully biodegradable materials.

[0008] Preferably, a waist is provided between the fixed plate and the covering plate, the fixed plate is cylindrical, and both side end surfaces of the fixed plate are concave inwardly to form a double concave structure; or the fixed plate and the covering plate are connected without a waist.

[0009] Preferably, the fixing plate and the covering plate are woven from a biodegradable silk mesh.

[0010] Preferably, a metal sheet made of a degradable biomedical magnesium alloy material is provided in the fixing plate.

[0011] Preferably, the metal sheet is provided with barbs and circular holes.

[0012] Preferably, the fixed disk and the covering disk are provided with flow-blocking films.

[0013] Preferably, the fixing plate is provided with barbs formed by heat-setting the degradable silk body.

[0014] Preferably, the connecting rivet comprises a wire rivet head, which is configured as a welding ball formed by heat setting treatment.

[0015] Preferably, the diameter of the fixed disk is set to 16-36 mm; the diameter of the covering disk is larger than the diameter of the fixed disk.

[0016] Preferably, the diameter of the cover disk is 2-14 mm larger than the diameter of the fixed disk.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The structure of the left atrial appendage occluder in the present invention is a fixed disk combined with a covering disk. The covering disk can completely cover the mouth of the left atrial appendage, so the opening size and depth requirements of the left atrial appendage are relatively low. It can be applied to single-leaf and multi-leaf left atrial appendage structures, and the indications are wider. The flat design of the covering disk can avoid the formation of secondary eddy currents at the left atrial appendage mouth after occlusion. The concave design of the covering disk can enhance the fitting strength of the covering disk and the atrial appendage mouth, reducing the occurrence of residual shunt.

[0019] 2) The materials used for the occluder in the present invention are degradable polymer materials and degradable biomedical magnesium alloy materials, both of which are completely degradable materials. After complete endothelialization, the materials used will gradually degrade, and no metal will remain in the human body.

[0020] 3) The fixed disk of the occluder of the present invention is fixed inside the left atrial appendage, and the covering disk covers the opening of the left atrial appendage. The diameter of the covering disk is 4-14 mm larger than that of the fixed disk, which has the effect of completely covering the opening of the left atrial appendage, thereby achieving the purpose of completely occluding the left atrial appendage.

[0021] 4) A biodegradable magnesium alloy sheet containing barbs and circular holes is embedded and sutured on the fixing disk of the present invention. The magnesium alloy sheet can play four roles: 1. The barbs can enhance the stability of the fixing disk in the body of the left atrial appendage; 2. The magnesium alloy sheet can enhance the radial support force of the fixing disk; 3. The magnesium alloy sheet can be developed under X-rays; 4. The circular holes on the magnesium alloy sheet are used to sew the magnesium alloy metal sheet to the occluder frame; the biodegradable magnesium alloy sheet is connected and fixed with degradable silk through the circular holes.

[0022] 5) In the present invention, the flow-blocking membranes of the fixed disk and the covering disk are both used to block the blood flow between the left atrial appendage and the left atrium.

[0023] 6) The dense mesh woven structure of the fixing disc and the covering disc in the present invention can play two roles: enhancing the flow blocking effect and enhancing the radial supporting force of the occluder.

[0024] 7) The welding ball designed in the present invention can play two roles: 1. Bundle the wires of the braided occluder skeleton to prevent the disc from spreading; 2. Be used to connect the delivery device and implant the occluder into the left atrial appendage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of a fully degradable left atrial appendage occluder of the present invention. Figure 1 .

[0026] Figure 2 This is a schematic diagram of the structure of a fully degradable left atrial appendage occluder of the present invention. Figure 2 .

[0027] Figure 3 This is a schematic diagram of the structure of a fully degradable left atrial appendage occluder of the present invention. Figure 3 .

[0028] Figure 4 This is a schematic diagram of the structure of a fully degradable left atrial appendage occluder of the present invention. Figure 4 .

[0029] Figure 5 This is a schematic diagram of the structure of a fully degradable left atrial appendage occluder of the present invention. Figure 5 .

[0030] Figure numerals: 1. fixing plate; 2. flow-blocking membrane; 3. covering plate; 4. metal sheet; 5. barb; 6. connecting rivet; 7. waist; 8. wire knot. DETAILED DESCRIPTION

[0031] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings:

[0032] like Figure 1-5 As shown, the present invention provides a fully biodegradable left atrial appendage occluder. The device comprises a fixing disc 1 and a covering disc 3. The fixing disc 1 is provided at one end of the device near the base of the left atrial appendage, and the covering disc 3 is provided at the other end. A connecting rivet 6 is provided on the side of the covering disc 3 near the opening of the left atrial appendage. The device is made of a fully biodegradable material. A waist 7 is provided between the fixing disc 1 and the covering disc 3. The fixing disc 1 is cylindrical, with both end surfaces of the fixing disc 1 inwardly concave, forming a biconcave structure. Alternatively, the fixing disc 1 and the covering disc 3 may be connected without the waist 7. The fixing disc 1 and the covering disc 3 are woven from a dense mesh of biodegradable silk. A metal sheet 4 made of a biodegradable biomedical magnesium alloy is provided within the fixing disc 1. The metal sheet 4 is provided with barbs 5 and circular holes. A flow-blocking membrane 2 is provided on the fixing disc 1 and the covering disc 3. The fixing disc 1 is provided with barbs 5 formed by heat-setting the biodegradable silk body. The connecting rivet 6 includes a wire rivet head, which is a fused ball formed by heat-setting. The diameter of the fixing disk 1 is set to 16-36 mm, and the diameter of the covering disk 3 is larger than the diameter of the fixing disk 1. The diameter of the covering disk 3 is 2-14 mm larger than the diameter of the fixing disk 1.

[0033] like Figure 1-5 As shown: The occluder structure design of the present invention includes:

[0034] 1) The structure of the occluder includes a fixed disk 1 and a cover disk 3. The structural feature of the fixed disk 1 is a cylindrical design, and the cylindrical disk surface near the bottom of the left atrial appendage is a double concave structure design (such as Figure 1 The fixing plate 1 is a double concave structure), and the structural feature of the covering plate 3 can be a flat design (such as Figure 1 The cover plate 3 is a flat design), or it can be a concave design (such as Figure 3 The cover plate 3 is a concave design).

[0035] There may be a waist 7 between the cover plate 3 and the fixed plate 1 (eg Figure 1 and Figure 2 Waist 7), or no waist 7 connection (such as Figure 3 ); There is a connecting rivet 6 at the proximal end of the auricle opening of the occluder.

[0036] 2) The main skeleton of the fixing plate 1 and the covering plate 3 is woven from a dense mesh of a biodegradable polymer material. The material can be one or more synthetic degradable polymers such as polydioxanone PDO, polylactic acid PLA, PLLA, PDLLA, PLGA, PGA, PCL, PHB, PVA, natural degradable polymers such as silk fibroin, collagen fiber, chitosan, or their copolymers.

[0037] 3) The biodegradable polymer filaments can be smooth or have a barbed design.

[0038] 4) A metal sheet 4 made of biodegradable magnesium alloy is embedded and sutured on the fixing plate 1. The sheet has a row of cut barbs 5 and circular holes (such as Figure 3 、 Figure 5 ); can also be made of barbs formed by heat-setting the biodegradable silk body involved in the fixed disk 1 weaving net; a plurality of silk knots 8 (such as the fixed disk 1 is attached) Figure 2 、 Figure 4 ).

[0039] 5) The waist 7 between the fixing plate 1 and the covering plate 3 is formed by a heat setting process.

[0040] 6) A layer of flow-blocking film 2 is sewn inside the fixing plate 1 and the covering plate 3. The materials for making the flow-blocking film 2 and the sutures are both biodegradable polymer materials.

[0041] 7) The wire rivet head of the cover disc 3 is a fusion ball formed by heat setting. The diameter of the occluder fixed disc 1 is 16-36 mm, and the diameter of the cover disc 3 is 2-14 mm larger than that of the fixed disc 1.

[0042] The effects achieved by adopting the present invention are:

[0043] 1) The structure of the left atrial appendage occluder in the present invention is a fixed disk 1 combined with a covering disk 3. The covering disk 3 can completely cover the mouth of the left atrial appendage, so the opening size and depth requirements of the left atrial appendage are relatively low, and it can be applicable to single-leaf and multi-leaf left atrial appendage structures, and the indications are wider. The flat design of the covering disk 3 structure can avoid the formation of secondary eddy currents at the left atrial appendage mouth after occlusion, and the concave design of the covering disk 3 structure can enhance the fitting strength of the covering disk 3 and the atrial appendage mouth, reducing the occurrence of residual shunt.

[0044] 2) The materials used for the occluder in the present invention are degradable polymer materials and degradable biomedical magnesium alloys, both of which are completely degradable materials. After complete endothelialization, the materials will gradually degrade, and no metal will remain in the human body.

[0045] 3) In the present invention, the occluder fixing disk 1 is fixed inside the left atrial appendage, and the covering disk 3 covers the opening of the left atrial appendage. The diameter of the covering disk 3 is 4-14 mm larger than that of the fixing disk 1, which has the effect of completely covering the opening of the left atrial appendage, thereby achieving the purpose of completely blocking the left atrial appendage.

[0046] 4) In the present invention, a biodegradable magnesium alloy sheet 4 containing barbs 5 and circular holes is sewn onto the fixation disc 1. This sheet serves four purposes: the barbs 5 enhance the stability of the fixation disc 1 within the body of the left atrial appendage; the magnesium alloy sheet 4 strengthens the radial support of the fixation disc 1; and the magnesium alloy sheet 4 allows for X-ray imaging. The circular holes are used to sew the magnesium alloy sheet 4 to the occluder frame; and the degradable magnesium alloy sheet 4 is connected and secured through the circular holes using biodegradable thread.

[0047] 5) In the present invention, the blocking membrane 2 of the fixing disk 1 and the covering disk 3 are both used to block the blood flow between the left atrial appendage and the left atrium.

[0048] 6) In the present invention, the fixing disc 1 and the covering disc 3 adopt a dense mesh woven structure, which can play two roles: enhancing the flow blocking effect and enhancing the radial supporting force of the occluder.

[0049] 7) The welding ball in the present invention can play two roles: it can bundle the wires of the braided occluder skeleton so that the disc surface does not spread out; and it can be used to connect the delivery device to implant the occluder into the left atrial appendage.

[0050] The LAA occluder provided by the present invention, after implantation, acts as a bridge for endothelial cells to climb. After a period of implantation, the surface of the LAA occluder is covered by newly formed endothelial tissue, achieving self-occlusion of the LAA. The occluder is eventually degraded by the body, leaving the LAA completely filled with its own tissue, thus avoiding the long-term complications and safety risks associated with metal retention in the body.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A fully degradable left atrial appendage occluder; characterized by: The occluder comprises a fixing plate and a covering plate; a fixing plate is provided at one end of the occluder near the bottom of the left atrial appendage, and a covering plate is provided at the other end; a connecting rivet is provided on one side of the covering plate near the opening of the left atrial appendage; the occluder is made of a completely biodegradable material; A waist is provided between the fixed plate and the cover plate, the fixed plate is set to be cylindrical, and both side end surfaces of the fixed plate are inwardly concave to form a double concave structure; or there is no waist connection between the fixed plate and the cover plate; The structural feature of the cover disc is a flat design or a concave design; The fixed disk is provided with a metal sheet made of a degradable biomedical magnesium alloy material; The metal sheet is provided with barbs and round holes; The diameter of the fixed disk is set to 16-36 mm; the diameter of the covering disk is larger than the diameter of the fixed disk; The diameter of the cover disk is 2-14 mm larger than the diameter of the fixed disk.

2. A fully degradable left atrial appendage occluder according to claim 1, characterized in that: The fixing disk and the covering disk are woven from a biodegradable silk mesh.

3. The fully degradable left atrial appendage occluder according to claim 1, characterized in that: The fixed disk and the covering disk are provided with flow-blocking films.

4. The fully degradable left atrial appendage occluder according to claim 1, wherein: The fixing plate is provided with barbs formed by heat-setting the degradable silk body.

5. The fully degradable left atrial appendage occluder according to claim 1, characterized in that: The connecting rivet comprises a wire rivet head, which is configured as a welding ball formed by heat setting treatment.

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