A membrane-free partially degradable left atrial appendage occluder

Abstract

The present invention relates to a membrane-free partially degradable left atrial appendage occluder, belonging to the technical field of medical devices. It comprises an upper disk, a stent body and a lower disk; a stent body is arranged between the upper disk and the lower disk; the shape of the occluder is set to be cylindrical or drum-shaped; and the upper disk is set to be a closed structure. The closed plug-type design reduces the compression of the occluder on the peripheral structural tissues of the left atrial appendage; reduces the complications caused by atrial appendage puncture; has a low requirement on the depth of the implanted left atrial appendage, and has a wide range of applications. The occluder is woven with a dense mesh to achieve the effect of blocking blood flow, replacing the traditional flow-blocking membrane, so that the occluder can pass through a smaller delivery sheath to avoid the occurrence of iatrogenic atrial septal defect. The use of degradable polymer materials reduces the amount of metal implanted in the left atrial appendage occluder and the heart load on the patient. Through the design of the internal molding ring of the occluder, the radial supporting force of the occluder is enhanced, and the stability of the occluder in the body is improved.

Description

Technical Field

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

[0002] According to survey data, stroke has become the leading cause of death in Chinese people, and China is one of the countries with the highest proportion of stroke risk factors in the world. There are 10.3 million new stroke patients each year worldwide. The latest statistics in my country show that the annual prevalence of stroke in China is 1114.8 / 100,000, and the mortality rate is 114.8 / 100,000. Given the high disability rate, high mortality rate, and high recurrence of stroke, understanding and preventing stroke is of great significance to the world, especially to China.

[0003] According to the 2013 Global Burden of Disease (GBD) study, more than 90% of strokes are caused by modifiable risk factors, and more than 75% of stroke patients can reduce their occurrence by controlling metabolic and behavioral risk factors. Non-valvular atrial fibrillation is one of the modifiable risk factors for stroke. Therefore, it is expected that stroke prevention can be achieved through effective intervention in atrial fibrillation.

[0004] As a new technology for preventing stroke and systemic embolic events in patients with non-valvular atrial fibrillation, transcatheter left atrial appendage occlusion has developed rapidly in recent years. In particular, with the development and application of different types of left atrial appendage occlusion devices and the publication of follow-up results of many clinical studies, the effectiveness and safety of left atrial appendage occlusion in preventing atrial fibrillation stroke and systemic embolic events have been clinically recognized.

[0005] However, the left atrial appendage occluders currently on the market at home and abroad are all metal occluders, which have many problems. For example, the cover disc of the cap-type occluder will cause abrasion to the ridge and mitral ring around the left atrial appendage, causing edema; incomplete cover occlusion leads to residual leakage; excessive load in the left atrial appendage compresses the left coronary artery branch, leading to complications such as myocardial ischemia. The above complications are less likely to occur in the plug-type occluder. Since the distal end (near the tip of the left atrial appendage) of the plug-type left atrial appendage occluder is an open design, there is a risk of causing pericardial tamponade caused by atrial appendage puncture. When used, it is affected by the depth of the atrial appendage structure. For a shallow left atrial appendage, the open-type plug-type occluder is relatively not the most preferred. On the other hand, the delivery sheath specifications used for the plug-type occluders currently on the market in China are all 14F, and the aperture caused by atrial septal puncture is large, which is prone to iatrogenic atrial septal defect. Therefore, this technical field urgently needs to solve the technical problem of the wear of the surrounding tissue structure of the atrial appendage by the metal occluder in the existing technology; as well as to enable the occluder to pass through a small-sized delivery sheath, reduce the complications of pericardial tamponade caused by atrial appendage puncture, reduce the amount of metal implanted in the left atrial appendage occluder, and reduce the load on the heart. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects in the prior art and solve the technical problem of the wear of the metal occluder on the tissue structure around the atrial appendage in the prior art; and to enable the occluder to pass through a small-sized delivery sheath, reduce the complications of pericardial tamponade caused by atrial appendage puncture, reduce the amount of metal implanted in the left atrial appendage occluder, and reduce the load on the heart.

[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 membrane-free partially degradable left atrial appendage occluder; comprising an upper disk surface, a stent body and a lower disk surface; a stent body is arranged between the upper disk surface and the lower disk surface; the shape of the occluder is set to be cylindrical or drum-shaped; and the upper disk surface is set to be a closed structure.

[0008] Preferably, the lower disk surface is set to a concave structure or a planar structure.

[0009] Preferably, the occluder manufacturing material includes shape memory alloy material and degradable polymer material.

[0010] Preferably, the stent body comprises a metal stent, and the metal stent is formed by weaving memory alloy wires or carving nickel-titanium tubes.

[0011] Preferably, the metal support is configured as a dense mesh structure.

[0012] Preferably, one end of the left atrial appendage occluder close to the bottom of the left atrial appendage is set as an upper disk surface, and the other end close to the left atrium is set as a lower disk surface; the upper and lower disk surfaces are set to be woven from dense meshes of wires made of degradable polymer materials.

[0013] Preferably, the upper disk surface is configured as a rivet-free woven structure, and a forming ring is provided at the center of the upper disk surface; the lower disk surface is provided with a bundle of wire rivet heads, and the rivet heads are provided with through holes.

[0014] Preferably, the stent body comprises a stent woven from degradable wires and nickel-titanium wires; the connection between the degradable wires and the nickel-titanium wires comprises a winding connection or a punching connection.

[0015] Preferably, the shape memory alloy material is a nickel-titanium alloy material, and the degradable polymer material is one or two of polylactic acid and polydioxanone or a copolymer.

[0016] Preferably, the diameter range of the left atrial appendage occluder stent body is set to 16-40 mm.

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

[0018] 1) The left atrial appendage structure of the present invention is a closed plug-type structure. The closed plug-type structure is different from the existing open plug-type structure in that the closed plug-type structure can reduce the complications of pericardial tamponade caused by atrial appendage puncture; it avoids the compression and wear of the occluder on the left atrial appendage ridge, mitral valve ring and other tissues; the left atrial appendage occluder with a plug-type structure has relatively lower requirements on the depth of the left atrial appendage, and can be applied to shallower or deeper left atrial appendage structures.

[0019] 2) The occluder of the present invention is provided with a concave structure, which can enhance the radial support force of the device and improve the stability of the device in the left atrial appendage. The occluder is provided with a non-concave structure, which can avoid the possibility of eddy currents forming again at the left atrial appendage opening.

[0020] 3) The stent of the occluder of the present invention is made of nickel-titanium alloy, which can meet the requirements of radial support force, completely block and prevent residual leakage. The upper and lower disks of the occluder are made of degradable materials, which can be degraded within a certain period of time after endothelialization, reducing the amount of metal implanted in patients and the load on the left atrial appendage.

[0021] 4) The stent of the present invention can enhance the success rate and effectiveness of stent manufacturing by weaving or carving. The two ends of the braided stent are closed to leave working space for the subsequent winding and weaving of the degradable wire and the nickel-titanium wire.

[0022] 5) The present invention is different from the previous left atrial appendage occluder, which has a design of 1-3 layers of flow-blocking membranes. The overall weaving method of the left atrial appendage designed by the present invention is a dense mesh weaving method, and the dense mesh weaving method can play an effect of blocking blood flow. The advantage of the occluder without a membrane is that the occluder can be passed through a smaller delivery sheath. That is, under the premise of ensuring the flow-blocking effect of the occluder, it can be achieved by passing through a smaller delivery sheath to avoid iatrogenic atrial septal defect. On the other hand, the nickel-titanium stent adopts a dense mesh weaving method, which can enhance the radial support force and development of the occluder in the body of the left atrial appendage.

[0023] 6) The present invention is different from the conventional plug-type left atrial appendage occluder with a distal opening design. The left atrial appendage occluder designed in the present invention has a distal closed design, which can reduce the scraping of the occluder to the deep part of the left atrial appendage, and reduce the occurrence of complications such as pericardial puncture and pericardial effusion.

[0024] 7) In the present invention, the interior of the left atrial appendage occluder is provided with a molding ring and a through hole, and the method of use is to pull the molding ring of the upper disk surface, through the through hole, and pull out the outside of the occluder through hole, thereby squeezing the upper and lower disk surfaces, thereby achieving the effect of strengthening the radial supporting force of the left atrial appendage occluder, ensuring that the occlusion is complete and there is no residual leakage. The lower disk surface of the left atrial appendage occluder has a wire rivet head, which can condense and bundle the degradable polymer wire material so that the disk surface does not spread; it can also be used to connect the conveying device to implant the occluder into the left atrial appendage.

[0025] 8) In the present invention, the nickel-titanium alloy stent body and the degradable upper and lower discs are woven and shaped separately, and different materials can be treated differently to ensure the performance of the occluder.

[0026] 9) In the present invention, the connection between the nickel-titanium alloy stent body and the degradable upper and lower disc surfaces is a winding connection or a perforated suture connection, which can achieve a stable connection between metal materials and non-metallic materials without affecting the performance of the device.

[0027] 10) The size range of the left atrial appendage occluder in the present invention meets the size of common left atrial appendages. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the left atrial appendage occluder with a concave lower disk surface according to the present invention.

[0029] Point A in the figure is the connection point between the biodegradable wire on the upper and lower disks and the nickel-titanium wire.

[0030] Figure 2 It is a schematic diagram of the overall structure of the occluder with a convex lower disk surface according to the present invention.

[0031] Point A in the figure is the connection point between the biodegradable wire on the upper and lower disks and the nickel-titanium wire.

[0032] Figure 3 For the present invention Figure 1 and Figure 2 Schematic diagram of the winding connection between the biodegradable wires on the upper and lower disks and the braided nickel-titanium wires at A in the middle.

[0033] Figure 4 For the present invention Figure 1 and Figure 2 Schematic diagram of the punched connection between the biodegradable wire on the upper and lower disks and the engraved nickel-titanium wire at A in the middle.

[0034] Figure 5 It is a top view of the upper disk of the left atrial appendage occluder in the present invention.

[0035] Figure numerals: 1. nickel-titanium wire skeleton; 2. upper disk surface; 3. auxiliary molding ring; 4. concave through-hole and rivet head on the lower disk surface; 5. auxiliary molding line; 6. convex through-hole and rivet head on the lower disk surface; 7. degradable wire; 8. braided nickel-titanium wire; 9. carved nickel-titanium wire bracket; 10. lower disk surface. DETAILED DESCRIPTION

[0036] In order to make the present invention more clearly understood, a preferred embodiment is described in detail with reference to the accompanying drawings as follows:

[0037] like Figure 1-5As shown, the present invention provides a membrane-free partially degradable left atrial appendage occluder; comprising an upper disk surface 2, a stent body and a lower disk surface 10; a stent body is arranged between the upper disk surface 2 and the lower disk surface 10; the shape of the occluder is set to be cylindrical or drum-shaped; the upper disk surface 2 is set to be a closed structure. The lower disk surface 10 is set to be a concave structure or a planar structure; the manufacturing material of the occluder includes a shape memory alloy material and a degradable polymer material. The stent body includes a metal stent, and the metal stent molding method includes memory alloy wire weaving molding or nickel titanium tube engraving molding. The metal stent is set to a dense mesh structure. The end of the left atrial appendage occluder close to the bottom of the left atrial appendage is set to the upper disk surface 2, and the other end close to the left atrium is set to the lower disk surface 10; the upper and lower disk surfaces are set to be woven from a dense mesh of wire made of a degradable polymer material. The upper disk surface 2 is set to be a rivet-free woven structure, and an auxiliary molding ring 3 is arranged in the center of the upper disk surface 2; the lower disk surface 10 is provided with a bundle of wire rivet heads, and the rivet heads are provided with through holes. The stent body includes a stent woven from degradable wire and nickel-titanium wire; the connection method between the degradable wire and the nickel-titanium wire includes winding connection or punching connection. The shape memory alloy material is set as nickel-titanium alloy material, and the degradable polymer material is set as one or two or copolymers of polylactic acid and polydioxanone. The diameter range of the left atrial appendage occluder stent body is set to 16-40mm.

[0038] The left atrial appendage occluder structure of the present invention is designed as follows:

[0039] 1) The structure of the left atrial appendage occluder is a closed plug structure, that is, the distal end (upper disc) of the occluder is a closed design, and the overall feature of the occluder can be a cylindrical or drum shape, including an upper disc, a stent body and a lower disc.

[0040] 2) The proximal end of the occluder (i.e., the lower disk) can be a concave structure or a flat (non-concave) structure (e.g., Figure 1 and Figure 2 ).

[0041] 3) The material of the left atrial appendage occluder is composed of a shape memory alloy material and a degradable polymer material. The shape memory alloy material may be a nickel-titanium alloy material, and the degradable polymer material may be one or more of polylactic acid, polydioxanone, or a copolymer thereof.

[0042] 4) The side of the left atrial appendage occluder is a metal stent, which can be woven from memory alloy wires or carved from nickel-titanium tubes. When weaving, the two ends of the stent are closed and woven in a spiral manner.

[0043] 5) Whether the stent is woven or carved, it is a dense mesh structure, that is, dense mesh weaving or dense mesh carving, such as the attached Figure 3 and Figure 4 .

[0044] 6) The two ends of the stent are respectively an upper disk surface and a lower disk surface, the upper disk surface is the end close to the bottom of the left atrial appendage tip, i.e., the distal end. The lower disk surface is the end close to the left atrial appendage mouth. The upper and lower disk surfaces are woven from a dense mesh of extremely fine degradable polymer materials.

[0045] 7) The upper and lower disks of the left atrial appendage occluder are woven from degradable polymer materials. The upper disk is woven without rivets, and a forming ring is connected to the center of the upper disk. The lower disk has a wire rivet head, which is a through hole formed by melting the degradable polymer wire material. Figure 1 and Figure 2 The structure of the through hole and rivet head 4 on the lower disk surface and the through hole and rivet head 6 on the lower disk surface.

[0046] 8) Since nickel-titanium wire and biodegradable polymer wire are two different materials and have different heat treatment temperature parameters, the nickel-titanium wire woven stent body and the biodegradable woven upper and lower discs are woven separately and heat treated to shape.

[0047] 9) The connection method between the biodegradable wire and the nickel-titanium wire braided stent is winding connection or punching connection.

[0048] 10) Wrapping connection is to pass the shaped upper and lower discs through the pores of the stent and the upper and lower discs with biodegradable wire or nickel-titanium wire to connect the discs with the stent body. Punching connection is to punch holes at both ends of the nickel-titanium wire stent body and fix the shaped upper and lower discs on the stent body with biodegradable wire.

[0049] 11) The size of the left atrial appendage occluder is based on the diameter of the stent, which ranges from 16-40mm.

[0050] Example

[0051] like Figure 1 The figure shows the overall structure of the left atrial appendage occluder, which is characterized by the concave structural design of the lower disk. It includes a nickel-titanium wire skeleton 1 (including braided or carved types), an upper disk 2 woven with degradable wires, an auxiliary molding ring 3, a lower disk 10, a concave through-hole and rivet head 4 and an auxiliary molding line 5. Through the auxiliary molding line 5, the auxiliary molding ring 3 is pulled downward and pulled out from the through-hole and rivet head 4 to increase the radial supporting force. Point A in the figure is the connection between the degradable wires of the upper and lower disks and the nickel-titanium wires (such as Figure 3 and Figure 4 (partial enlarged view).

[0052] like Figure 2Shown is another schematic diagram of the overall structure of the left atrial appendage occluder, which is characterized by a convex lower disk structure design. It includes a nickel-titanium wire skeleton 1 (including braided or engraved), an upper disk 2 woven with degradable wire, an auxiliary molding ring 3, a lower disk 10, a convex through-hole rivet head 6 and an auxiliary molding line 5. Through the auxiliary molding line 5, the auxiliary molding ring 3 is pulled downward and pulled out from the through-hole rivet head 6 to increase the radial supporting force. Point A in the figure is the connection between the degradable wire of the upper and lower disks and the nickel-titanium wire (such as Figure 3 and Figure 4 (partial enlarged view).

[0053] like Figure 3 The figure shows a schematic diagram of the winding connection between the upper and lower disc biodegradable wires 7 and the braided nickel-titanium wires 8.

[0054] like Figure 4 Shown is a schematic diagram of the punching connection between the upper and lower disc degradable wire 7 and the engraved nickel-titanium wire bracket 9. The engraved nickel-titanium wire bracket 9 has engraved holes through which the degradable wire 7 can pass for connection.

[0055] like Figure 5 The top view of the upper disk of the degradable left atrial appendage occluder is shown, which is characterized by a membrane-free woven structure and a flat disk surface. The top view of the upper disk is a rivet-free woven structure with a flat disk surface.

[0056] The present invention provides a membrane-free partially degradable left atrial appendage occluder.

[0057] The overall structure of the occluder is a closed plug design, which reduces the pressure of the occluder on the surrounding structural tissues of the left atrial appendage; reduces complications caused by atrial appendage puncture; and has low requirements for the depth of the implanted left atrial appendage, and has a relatively wide range of applications.

[0058] The left atrial appendage occluder uses a dense mesh weaving method to achieve the effect of blocking blood flow, replacing the flow-blocking membrane of the traditional left atrial appendage occluder. It can realize the occluder through a smaller delivery sheath and avoid the occurrence of iatrogenic atrial septal defect.

[0059] The material of the left atrial appendage occluder is made of memory alloy material and degradable polymer material, which is partially degradable, reducing the amount of metal implanted in the left atrial appendage occluder and the heart burden on the patient.

[0060] The left atrial appendage occluder is designed with an internal molding ring to enhance the radial support force of the occluder and improve the stability of the occluder in the body.

[0061] The size range of the left atrial appendage occluder meets the sizes of different left atrial appendages.

[0062] The above is only a preferred embodiment of the present invention, and is not any formal or substantial limitation of the present invention. 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 protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present invention, can make some changes, modifications and equivalent changes made by using the technical content disclosed above, which are equivalent embodiments of the present invention; at the same time, any changes, modifications and evolutions of any equivalent changes 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 membrane-free partially degradable left atrial appendage occluder; characterized in that: It includes an upper plate, a stent body and a lower plate; the stent body is arranged between the upper plate and the lower plate; the occluder is cylindrical or drum-shaped; the upper plate is a closed structure; The occluder manufacturing materials include shape memory alloy materials and degradable polymer materials; The stent body comprises a metal stent, and the metal stent is formed by weaving memory alloy wires or carving nickel-titanium tubes; The metal support is set to a dense mesh structure; The end of the left atrial appendage occluder close to the bottom of the left atrial appendage is set as an upper disk surface, and the other end close to the left atrium is set as a lower disk surface; the upper and lower disk surfaces are woven from dense meshes of wires made of degradable polymer materials.

2. The membrane-free partially degradable left atrial appendage occluder according to claim 1, characterized in that: The lower disk surface is set to a concave structure or a flat structure.

3. The membrane-free partially degradable left atrial appendage occluder according to claim 1, characterized in that: The upper disk surface is set as a rivet-free braided structure, and a forming ring is provided in the center of the upper disk surface; the lower disk surface is provided with a bundle of wire rivet heads, and the rivet heads are provided with through holes.

4. The membrane-free partially degradable left atrial appendage occluder according to claim 1, characterized in that: The stent body comprises a stent woven from degradable silk and nickel-titanium silk; the connection method between the degradable silk and the nickel-titanium silk comprises a winding connection or a punching connection.

5. The membrane-free partially degradable left atrial appendage occluder according to claim 3, characterized in that: The shape memory alloy material is a nickel-titanium alloy material, and the degradable polymer material is one or two of polylactic acid and polydioxanone or a copolymer.

6. The membrane-free partially degradable left atrial appendage occluder according to claim 1, characterized in that: The diameter range of the left atrial appendage occluder stent body is set to 16-40 mm.

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