Left Atrial Appendage Occluder

Abstract

The present invention provides a left atrial appendage occluder, comprising an occluding disc and an anchoring disc connected to the occluding disc, wherein the occluding disc is a mesh structure, a flow-blocking membrane is arranged inside, and the distal end of the occluding disc is fixed by a tubular component; the tubular component is provided with a plurality of support rods at the other end relative to the fixed occluding disc, wherein the support rods are extended from a direction relative to the occluding disc, and the proximal ends of the support rods span the center of the tubular component to the opposite side, and the plurality of support rods are arranged in a cross-radial manner to form an anchoring disc, and a specific angle is formed between the proximal ends of the support rods and the central axis of the tubular component. In addition, a preferred embodiment comprises a modified flow-blocking membrane to improve biocompatibility, rapid endothelialization, and reduce thrombosis. A left atrial appendage occluder of the present invention has a good effect of blocking the outflow of thrombus in the left atrial appendage, can be repeatedly positioned, has stable fixation, and has good fatigue resistance.

Description

[0001] This application is a divisional application of the original Chinese invention patent application CN201680072308.4. The application date of the original application is December 26, 2016, and the name of the invention in the original application is "Left Atrial Appendage Occluder".

[0002] The original application was an invention patent application entering the Chinese national phase based on the international application PCT / CN2016 / 112062 with a filing date of December 26, 2016 under the Patent Cooperation Treaty.

[0003] The international application, the original application and the present application all claim priority to the following patent applications:

[0004] Chinese invention patent application entitled “Left Atrial Appendage Occluder” with application number CN201511003714.9, filed on December 29, 2015; and

[0005] The Chinese invention patent application named “Left Atrial Appendage Occluder” with application number CN201610119169.8 was filed on March 2, 2016. Technical Field

[0006] The invention relates to an implantable medical device, in particular to a left atrial appendage occluding device which has good effect of blocking the outflow of thrombus in the left atrial appendage, can be repeatedly positioned, is stably fixed, and is fatigue-resistant. Background Art

[0007] At present, with the development of interventional devices, many diseases that cannot be cured by surgery have been cured. Compared with surgical treatment methods, interventional treatments are less invasive, have faster recovery, and better efficacy. After nearly half a century of development, interventional treatments have developed rapidly, and a variety of interventional medical device products have been produced, allowing more and more diseases and patients to be treated.

[0008] Atrial fibrillation (AF) is one of the most common arrhythmias. In addition to the discomfort caused by palpitations, the occurrence of complications such as thromboembolism is the main hazard of AF. About 90% of thrombi originate from the left atrial appendage in patients with non-valvular and non-rheumatic AF. About 5% of patients with AF suffer from thromboembolic events and strokes each year. The mortality rate caused by stroke is as high as 50%. Therefore, how to prevent and treat stroke caused by AF thrombus is of great clinical significance. At present, the methods for preventing and treating AF thrombus include surgery, drug therapy and interventional therapy. Among them, surgical occlusion of the left atrial appendage has not been widely used due to its large trauma and high risk. At present, the most common method for patients with AF to prevent stroke is long-term oral anticoagulants, but anticoagulants have the risk of bleeding. About 14% to 44% of patients cannot receive long-term drug anticoagulant therapy due to contraindications. In recent years, a most advanced interventional treatment has been developed at home and abroad. Through a tiny catheter, a special left atrial appendage occluder is implanted into the left atrial appendage to block the left atrial appendage and prevent and treat thrombotic events and stroke in patients with atrial fibrillation. This treatment method has low trauma, low risk, fast recovery and good efficacy, thus becoming the preferred treatment method for preventing and treating stroke caused by atrial fibrillation.

[0009] At present, this type of device can be roughly divided into braided type, cutting type and mixed type from the perspective of structure. These types of left atrial appendage occluders can be delivered into the left atrial appendage through catheter intervention to achieve left atrial appendage occlusion. However, there are considerable limitations. The anatomical structure of each person's left atrial appendage is complex and has different shapes, such as oval, peanut, etc. The inner wall of the left atrial appendage is uneven, irregular in shape, and the wall of the left atrial appendage is thin. Therefore, it is difficult to achieve the ideal occlusion effect without piercing the heart wall and firmly anchoring it in the left atrial appendage without falling off.

[0010] Such as the braided left atrial appendage occluder designed by invention patents CN1799521A and CN101146570A. They use the uneven structure of the fixed disk surface of the occluder to anchor the occluder, and the occluding disk is blocked at the left atrial appendage mouth to achieve the effect of occlusion. The design advantage of this structure is that the structure is simple, the processing difficulty is small, and the cost is low. However, the anchoring force of the braided fixed disk is low, and it is difficult to adapt to the left atrial appendage morphology of various shapes. Even if the anchor hook is sutured on the fixed disk, it is still difficult to penetrate into the left atrial appendage wall when the fixed disk is squeezed and deformed to achieve stable fixation. Moreover, the fixed disk will affect the shape of the occluding disk after being squeezed and deformed in the left atrial appendage, resulting in poor blocking effect.

[0011] Such as the cutting type left atrial appendage occluder involved in the invention patents CN1711978A and CN1342056A. They cut the nickel-titanium metal tube and heat-treat it into the designed shape. The part in contact with the inner wall of the left atrial appendage is designed with an outwardly tilted anchoring thorn, which pierces the inner wall of the left atrial appendage to achieve stable fixation. Usually, a flow-blocking membrane is sutured on the mesh frame of the cutting type to achieve the effect of left atrial appendage occlusion. The advantage of this structural design is that the entire occluder is integrally formed, has strong rigidity, is easily fixed on the inner wall of the left atrial appendage, and the designed anchoring thorn is easy to pierce the inner wall of the left atrial appendage, stably fixes, and prevents the occluder from falling off. However, the cutting type left atrial appendage occluder has limited deformation ability in shape and cannot adapt to the left atrial appendage morphology of various shapes, which greatly limits its use. After the cutting type left atrial appendage occluder is plugged into the left atrial appendage, the part in the left atrium will usually be recessed with the atrial wall, forming a new "left atrial appendage" area, increasing the risk of new thrombosis. The anchoring thorn of the cutting type left atrial appendage occluder is usually inserted into the left atrium to stabilize the occluder and prevent it from falling off. However, the anchoring thorn inserted into the left atrium will get stuck on the edge of the sheath wall during repeated positioning and retrieval of the occluder, making it impossible to retrieve the occluder and repeat positioning.

[0012] Such as the hybrid left atrial appendage occluder involved in the invention patents CN102805654A and CN103099652A. In these designs, the occluding disc adopts a braided type, and a flow-blocking membrane is usually sutured inside the occluding disc to occlude the left atrial appendage. The fixing disc is cut by a nickel-titanium metal tube and heat-treated to form the designed shape. An outwardly tilted anchoring thorn is designed at the part in contact with the inner wall of the left atrial appendage, which pierces the inner wall of the left atrial appendage to achieve stable fixation. The hybrid left atrial appendage occluder effectively solves most of the problems of the cutting type left atrial appendage occluder. However, the occluding disc of CN102805654A is a planar structure, which is not suitable for the occlusion of the arc structure in the left atrium; in addition, the support rods of the anchoring disc are interconnected, the connecting parts of the rods are deformed greatly, the processing is difficult, the fatigue resistance is poor, and it is easy to break in the body, resulting in the risk of cardiac perforation. In addition, as in CN103099652A, an anchoring thorn of the fixed disk is usually stabbed into the left atrium, which plays a role in stabilizing the occluder and preventing the occluder from falling off. But the anchoring thorn stabbing into the left atrium is repeatedly positioned, and when the occluder is recovered, it will be stuck on the edge of the sheath wall, making the occluder unable to be recovered and repeatedly positioned. And the fixed disk of this hybrid left atrial appendage occluder is usually deformed larger, with the direction of the anchoring thorn flipped, causing the tension force and deformation amount of the fixed disk to reach the limit value of the material. The fatigue strength of this device in permanent implantation is poor, and it is easy to break, puncture other tissues such as the heart, and endanger life.

[0013] In addition, CN104352261A discloses a left atrial appendage occluder with an improved structure, in which the connecting plate provides support for the anchor plate to form a rigid structure, so that the deformation is large and the processing is difficult. In addition, the plane structure of the anchor plate is larger than the diameter of the anchor plate during the opening and recovery process, which is easy to puncture the heart and other tissues, endangering life. The opening schematic diagram is shown in FIG. Fig.11 shown.

[0014] Therefore, considering the advantages and disadvantages of various left atrial appendage occluders, it is urgent to develop a left atrial appendage occluder that can effectively occlude the left atrial appendage, can be repeatedly positioned, stably fixed, and can be permanently implanted. Summary of the invention

[0015] The purpose of the present invention is to provide a left atrial appendage (LAA) occluder which has good effect of blocking the outflow of thrombus in the left atrial appendage, can be repeatedly positioned, fixed stably and is fatigue-resistant.

[0016] In order to achieve the above-mentioned object, the technical solution provided by the present invention is: to provide a left atrial appendage occluder, comprising an occluding disc and an anchoring disc connected to the occluding disc,

[0017] The occluding disc is a mesh structure with a flow-blocking membrane disposed inside. The distal end of the occluding disc is fixed by a tubular component, and the other end of the tubular component relative to the fixed occluding disc is connected to the anchor disc. The proximal end of the occluding disc is fixed by a bolt head and is provided with a structure connected to a delivery device.

[0018] The other end of the tubular component relative to the fixed occluding disk is provided with a plurality of support rods, the support rods extend from a direction relative to the occluding disk, the proximal end of the support rods spans the center of the tubular component to the opposite side, the plurality of support rods are arranged in a cross-radial pattern to form an anchoring disk, the angle α between the proximal end of the support rod and the central axis of the tubular component is 40-55 degrees, and the distal end of the support rod is bent inward.

[0019] Preferably, when the occluding disc and the anchoring disc are unfolded, the height of the entire occluder is 12-20 mm, the height of the anchoring disc is 9-15 mm, and the height of the occluding disc is 3-5 mm.

[0020] Through the above-mentioned preferred structural design, the anchor disk of the left atrial appendage occluder of the present invention is concave in shape, which is helpful for retracting and releasing the anchor disk with the sheath of the delivery device. When the occluder is pushed out and / or recovered by the sheath, the diameter of the anchor disk with a concave shape during the contraction process is no larger than the diameter when it is opened, and it can slowly shrink to enter the sheath of the delivery device, thereby avoiding damage to the left atrial appendage and improving safety and efficiency of use.

[0021] Preferably, the length of the inwardly curved portion at the distal end of the support rod is 1-5 mm. The number of the support rods is selected from a natural number of 2-50, preferably an odd number. The inwardly curved portion at the distal end of at least one of the support rods is used to be provided with one or more anchoring thorns on the side close to the atrial appendage, and the angle at which the anchoring thorns can be opened outward relative to the support rod is 20-45 degrees. When the anchor plate is unfolded, the anchor plate is against the inner wall of the left atrial appendage, and the anchoring thorns pierce the inner wall of the left atrial appendage to stabilize the fixation of the anchor plate in the left atrial appendage. The anchor plate formed by the support rod has a good fixing effect inside the atrial appendage.

[0022] The distal end of the support rod is provided with a round ball head, and the proximal end of the occlusion disc is fixed with a bolt head and provided with a threaded structure connected to the delivery device. This prevents the end of the support rod from damaging the left atrial appendage when the support rod is opened and / or recovered, and the threaded structure is provided to facilitate the delivery, opening and recovery of the left atrial appendage occluder.

[0023] The diameter of the occluding disk is slightly larger than that of the anchoring disk, wherein the diameter of the occluding disk is approximately 2-6 mm larger than that of the anchoring disk, and is suitable for single-leaf left atrial appendage; the diameter of the occluding disk is approximately 6-12 mm larger than that of the anchoring disk, and is suitable for double-leaf left atrial appendage, matching the left atrial appendage structure, thereby having a wider range of applications.

[0024] The processing scheme of the left atrial appendage of the occluder can be that the root of the anchoring thorn is on the support rod, the anchoring thorn is cut into the shape of the anchoring thorn by laser, and the angle of the anchoring thorn is fixed by heat treatment of the mold, and the anchoring thorn automatically opens outward without pressure, and the anchoring thorn can be retracted to the support rod when compressed. The occluding disk and the occluding disk are made of memory alloy material, preferably nickel-titanium alloy wire, which is formed into the desired shape by heat treatment; the tubular component is selected from a steel sleeve or an alloy sleeve component.

[0025] A further preferred solution is that a hole may be provided on the support rod for suturing a PET (polyethylene terephthalate) flow-blocking membrane on the anchoring plate to prevent the outflow of thrombus in the left atrial appendage.

[0026] The flow-blocking film may be a PET flow-blocking film that has not been modified or has been chemically modified.

[0027] The PET flow-blocking membrane is a chemically modified PET flow-blocking membrane, which utilizes the reaction of replacing ester groups with amide groups, and the contact angle of the chemically modified PET flow-blocking membrane is less than 90°, which enhances hydrophilicity. The flow-blocking membrane undergoes surface chemical treatment to make the surface anionized, which not only reduces platelet adhesion on the surface of the occluding disk, but also improves the hydrophilicity and biocompatibility of the flow-blocking membrane, and can achieve rapid endothelialization. The degree of endothelialization in a short period of time is much higher than that of the unmodified PET flow-blocking membrane, reducing the risk of thrombosis associated with the occluder.

[0028] Specifically, the PET flow-blocking film utilizes the reaction of replacing ester groups with amide groups to graft molecules with sodium sulfonate groups on one side onto the surface of the flow-blocking film, so that the PET flow-blocking film is electronegative. Such a PET flow-blocking film can adsorb the positively charged dye toluidine blue.

[0029] The chemical modification method of the PET flow-blocking film is as follows: the PET flow-blocking film is placed in a container, a mixed solvent of water and 1,4-dioxane is added, an alkane with a primary amino group and a sulfonic acid group at the end, and a catalyst are added, the mixture is stirred at 50-100° C. for 2-24 hours, and the flow-blocking film is taken out after the reaction is completed.

[0030] The alkane of the sulfonic acid group is 3-aminopropanesulfonic acid, 4-aminobutanesulfonic acid, 5-aminopentanesulfonic acid or 6-aminohexanesulfonic acid.

[0031] The catalyst is sodium hydroxide, potassium hydroxide or ammonia water.

[0032] More specifically, the volume ratio of water to 1,4-dioxane is 5:1. After the reaction is completed, the flow-blocking membrane is taken out and repeatedly washed with deionized water and anhydrous alcohol.

[0033] For example, a preferred method for chemically modifying the PET flow-blocking film is as follows: 50 pieces of PET flow-blocking films are placed in a 250 mL round-bottom flask, 200 mL of a mixed solvent of water and 1,4-dioxane in a volume ratio of 5:1 is added, 0.5 g of an alkane having a primary amine group and a sulfonic acid group at the end, and 1 g of a catalyst are added, and the mixture is stirred at 50-100° C. for 2-24 hours. After the reaction is completed, the flow-blocking film is taken out and repeatedly washed with deionized water and anhydrous alcohol for 5 times.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] The anchoring plate of the left atrial appendage occluder of the present invention is in a concave shape, which is helpful for retracting and releasing the anchoring plate with the sheath of the delivery device. When the sheath is used to open and / or recover the occluder, the diameter of the anchoring plate in the concave shape during the contraction process is no larger than the diameter when it is opened, and it can be slowly reduced to enter the sheath of the delivery device, thereby avoiding damage to the left atrial appendage and improving safety and efficiency of use.

[0036] The anchoring plate structure of the left atrial appendage occluder of the present invention has a soft and stable deformation and excellent fatigue resistance for permanent implantation, and can adapt to left atrial appendage cavities of various shapes and sizes.

[0037] The two-stage design of the left atrial appendage occluder of the present invention enables the occluder to adapt to left atrial appendage cavities of various shapes and sizes.

[0038] The left atrial appendage occluder of the present invention can simultaneously have the advantages of stable anchoring and effective occlusion of the left atrial appendage.

[0039] The left atrial appendage occluder of the present invention can be used not only to occlude a single-leaf left atrial appendage, but also to occlude a double-leaf left atrial appendage.

[0040] The left atrial appendage occluder of the present invention can be repeatedly positioned. In some cases, if the placement effect is not good, the occluder can be retracted into the sheath tube without releasing the delivery push rod, and the positioning and placement can be repeated until a satisfactory anchoring and occlusion effect is achieved, thereby greatly reducing the risk of surgery.

[0041] The left atrial appendage occluder of the present invention can use a smaller delivery system, further reducing the damage to the blood vessels caused by the delivery device during the operation.

[0042] The flexible connection between the left atrial appendage occluder and the push rod of the present invention greatly reduces the tension applied to the occluder by a delivery device such as the push rod during surgery, thereby making the placement of the occluder more accurate.

[0043] The flow-blocking membrane of the left atrial appendage occluder of the present invention is subjected to surface chemical treatment to make the surface negatively ionized, which not only reduces platelet adhesion on the surface of the occluding disk, but also improves the hydrophilicity and biocompatibility of the flow-blocking membrane, and can achieve rapid endothelialization. The degree of endothelialization in a short period of time is much higher than that of the unmodified PET flow-blocking membrane, thereby reducing the risk of thrombosis associated with the occluder.

[0044] The present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, which are used to illustrate embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of a preferred embodiment of the left atrial appendage occluder of the present invention.

[0046] Figure 2 It is a schematic diagram of the third embodiment of the left atrial appendage occluder of the present invention.

[0047] Figure 3 It is a schematic diagram of the fourth embodiment of the left atrial appendage occluder of the present invention.

[0048] Figure 4 middle, Figure 4 a is Figure 1 A schematic diagram showing the position of the fifth embodiment of the left atrial appendage occluder in the anatomical structure of a single-leaf left atrial appendage; Figure 4 b is Figure 1 A schematic diagram showing the position of the fifth embodiment of the left atrial appendage occluder in the anatomical structure of a bilobed left atrial appendage; Figure 4 c is Figure 3 The schematic diagram of the position of the fifth embodiment of the left atrial appendage occluder in the bilobed left atrial appendage anatomical structure is shown.

[0049] Figure 5 middle, Figure 5 a is Figure 1 The schematic diagram of the state where the anchoring plate of the left atrial appendage occluder has just come out of the sheath of the delivery device is shown; Figure 5 b is Figure 1 The schematic diagram of the state in which the anchoring plate half of the delivery device of the left atrial appendage occluder is out of the sheath tube is shown; Figure 5 c is Figure 1 The diagram shown is a schematic diagram of a state in which the anchoring disc of the left atrial appendage occluder is completely out of the sheath of the delivery device.

[0050] Figure 6 The schematic diagram of the chemical reaction equation for chemical modification of the flow-blocking membrane of the left atrial appendage occluder of the present invention is shown, wherein n=500-5000, and R: CH2, C2H4, C3H6 or C4H8.

[0051] Figure 7 This is a schematic diagram of a dyeing experiment for chemical modification of the flow-blocking membrane of the left atrial appendage occluder of the present invention.

[0052] Figure 8 It is a schematic diagram of the contact angle test of the flow-blocking membrane of the left atrial appendage occluder of the present invention after chemical modification and dyeing, LA is the left contact angle, and RA is the right contact angle.

[0053] Fig. 9 The figure is a bar graph showing the contact angle test results of the ePTFE (expanded polytetrafluoroethylene) reference substance, the flow-blocking membrane before chemical modification, and the flow-blocking membrane of the left atrial appendage occluder of the present invention at different chemical modification times.

[0054] Fig.10 This is a postoperative anatomical image. Fig.10 a and 10b are anatomical images 1 day and 1 month after surgery, respectively.

[0055] Fig.11 This is a schematic diagram of opening or retracting CN104352261A. DETAILED DESCRIPTION

[0056] Embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals represent like elements throughout the several views.

[0057] Example 1

[0058] like Figure 1 A left atrial appendage occluder comprises an occluding disc 106 and an anchoring disc 101 connected to the occluding disc.

[0059] The occluding disc is a mesh structure, with a flow blocking membrane 108 disposed inside. The distal end of the occluding disc is fixed by a tubular component 109, and the other end of the tubular component relative to the fixed occluding disc is connected to the anchor disc. The proximal end of the occluding disc is fixed by a bolt head 110 and is provided with a structure connected to a delivery device.

[0060] A plurality of support rods 102 are provided at the other end of the tubular component relative to the fixed occluding disk, and the support rods extend from a direction relative to the occluding disk. The proximal ends 102b of the support rods span the center of the tubular component to the opposite side. The plurality of support rods are arranged in a cross-radial pattern to form an anchoring disk 101. The angle α between the proximal ends 102b of the support rods and the central axis of the tubular component is 40-55 degrees, and the distal ends 102a of the support rods are bent inwardly.

[0061] Example 2

[0062] like Figure 1 A left atrial appendage occluder comprises an occluding disc 106 and an anchoring disc 101 connected to the occluding disc.

[0063] The occluding disc is a mesh structure, with a flow blocking membrane 108 disposed inside. The distal end of the occluding disc is fixed by a tubular component 109, and the other end of the tubular component relative to the fixed occluding disc is connected to the anchor disc. The proximal end of the occluding disc is fixed by a bolt head 110 and is provided with a structure connected to a delivery device.

[0064] A plurality of support rods 102 are provided at the other end of the tubular component relative to the fixed occluding disk, and the support rods extend from a direction relative to the occluding disk. The proximal ends 102b of the support rods span the center of the tubular component to the opposite side. The plurality of support rods are arranged in a cross-radial pattern to form an anchoring disk 101. The angle α between the proximal ends 102b of the support rods and the central axis of the tubular component is 40-55 degrees, and the distal ends 102a of the support rods are bent inwardly.

[0065] When the occluding disc and the anchoring disc are unfolded, the height of the entire occluding device is 12-20 mm, the height of the anchoring disc is 9-15 mm, and the height of the occluding disc is 3-5 mm.

[0066] Example 3

[0067] like Figure 2 A left atrial appendage occluder comprises an occluding disc 106 and an anchoring disc 101 connected to the occluding disc.

[0068] The occluding disc is a mesh structure, with a flow blocking membrane 108 disposed inside. The distal end of the occluding disc is fixed by a tubular component 109, and the other end of the tubular component relative to the fixed occluding disc is connected to the anchor disc. The proximal end of the occluding disc is fixed by a bolt head 110 and is provided with a structure connected to a delivery device.

[0069] A plurality of support rods 102 are provided at the other end of the tubular component relative to the fixed occluding disk, and the support rods extend from a direction relative to the occluding disk. The proximal ends 102b of the support rods span the center of the tubular component to the opposite side. The plurality of support rods are arranged in a cross-radial pattern to form an anchoring disk 101. The angle α between the proximal ends 102b of the support rods and the central axis of the tubular component is 40-55 degrees, and the distal ends 102a of the support rods are bent inwardly.

[0070] The length of the inwardly curved portion of the distal end 102a of the support rod is 1-5 mm, and the number of the support rods is 6. The inwardly curved portion of at least one of the distal ends of the support rods is used to be provided with one or more anchoring thorns 104 on the side close to the atrial appendage, and the angle at which the anchoring thorns can be opened outward relative to the support rods is 20-45 degrees. When the anchor plate is unfolded, the anchor plate is against the inner wall of the left atrial appendage, and the anchoring thorns pierce the inner wall of the left atrial appendage to stabilize the fixation of the anchor plate in the left atrial appendage.

[0071] The distal end of the support rod is provided with a round ball head 111, and the proximal end of the occluding disc is fixed with a bolt head and provided with a threaded structure connected with the delivery device.

[0072] Example 4

[0073] like Figure 2 A left atrial appendage occluder comprises an occluding disc 106 and an anchoring disc 101 connected to the occluding disc.

[0074] The occluding disc is a mesh structure, with a flow blocking membrane 108 disposed inside. The distal end of the occluding disc is fixed by a tubular component 109, and the other end of the tubular component relative to the fixed occluding disc is connected to the anchor disc. The proximal end of the occluding disc is fixed by a bolt head 110 and is provided with a structure connected to a delivery device.

[0075] A plurality of support rods 102 are provided at the other end of the tubular component relative to the fixed occluding disk, and the support rods extend from a direction relative to the occluding disk. The proximal ends 102b of the support rods span the center of the tubular component to the opposite side. The plurality of support rods are arranged in a cross-radial pattern to form an anchoring disk 101. The angle α between the proximal ends 102b of the support rods and the central axis of the tubular component is 40-55 degrees, and the distal ends 102a of the support rods are bent inwardly.

[0076] The length of the inwardly curved portion of the distal end 102a of the support rod is 1-5 mm, and the number of the support rods is 6. The inwardly curved portion of at least one of the distal ends of the support rods is used to be provided with one or more anchoring thorns 104 on the side close to the atrial appendage, and the angle at which the anchoring thorns can be opened outward relative to the support rods is 20-45 degrees. When the anchor plate is unfolded, the anchor plate is against the inner wall of the left atrial appendage, and the anchoring thorns pierce the inner wall of the left atrial appendage to stabilize the fixation of the anchor plate in the left atrial appendage.

[0077] The distal end of the support rod is provided with a round ball head 111, and the proximal end of the occluding disc is fixed with a bolt head and provided with a threaded structure connected with the delivery device.

[0078] like Figure 3 As shown, the support rod may also be provided with a hole for suturing a PET flow-blocking membrane on the anchoring plate to prevent the outflow of thrombus in the left atrial appendage.

[0079] Example 5

[0080] like Figure 2 A left atrial appendage occluder comprises an occluding disc 106 and an anchoring disc 101 connected to the occluding disc.

[0081] The occluding disc is a mesh structure, with a flow blocking membrane 108 disposed inside. The distal end of the occluding disc is fixed by a tubular component 109, and the other end of the tubular component relative to the fixed occluding disc is connected to the anchor disc. The proximal end of the occluding disc is fixed by a bolt head 110 and is provided with a structure connected to a delivery device.

[0082] A plurality of support rods 102 are provided at the other end of the tubular component relative to the fixed occluding disk, and the support rods extend from a direction relative to the occluding disk. The proximal ends 102b of the support rods span the center of the tubular component to the opposite side. The plurality of support rods are arranged in a cross-radial pattern to form an anchoring disk 101. The angle α between the proximal ends 102b of the support rods and the central axis of the tubular component is 40-55 degrees, and the distal ends 102a of the support rods are bent inwardly.

[0083] The length of the inwardly curved portion of the distal end 102a of the support rod is 1-5 mm, and the number of the support rods is 6. The inwardly curved portion of at least one of the distal ends of the support rods is used to be provided with one or more anchoring thorns 104 on the side close to the atrial appendage, and the angle at which the anchoring thorns can be opened outward relative to the support rods is 20-45 degrees. When the anchor plate is unfolded, the anchor plate is against the inner wall of the left atrial appendage, and the anchoring thorns pierce the inner wall of the left atrial appendage to stabilize the fixation of the anchor plate in the left atrial appendage.

[0084] The distal end of the support rod is provided with a round ball head 111, and the proximal end of the occluding disc is fixed with a bolt head and provided with a threaded structure connected with the delivery device.

[0085] like Figure 4 As shown in a, the diameter of the occluding disk is slightly larger than the anchoring disk, wherein the diameter of the occluding disk is approximately 2-6 mm larger than the anchoring disk, and is suitable for single-leaf left atrial appendage.

[0086] However, the aforementioned size is difficult to completely occlude the bilobed left atrial appendage. Figure 4 Therefore, another preferred solution is as follows Figure 4As shown in c, the diameter of the occluding disk is slightly larger than the anchoring disk, wherein the diameter of the occluding disk is approximately 6-12 mm larger than the anchoring disk, and is suitable for a bilobate left atrial appendage.

[0087] Example 6

[0088] like Figure 5 a, Figure 5 b and Figure 5 c, the process of the anchor plate 101 entering and exiting the sheath tube 115 of the delivery device has the following characteristics: In order to clearly illustrate the process of the anchor plate 101 entering and exiting the sheath tube, Figure 5 a, Figure 5 b and Figure 5 In c, the support rods 102 of the anchor plate 101 are simplified into two, and the support rods 102 are straightened and cross-shaped in the sheath tube, and the anchor barbs 104 face the opposite oblique inner side of the central end 107 of the tubular component. The inner wall of the sheath tube 115 will not be scratched during the pushing process. Under the thrust of the pushing rod, the elbow of the distal end 102a of the support rod 102 is slowly pushed out of the sheath tube 115 ( Figure 5 a), unfold along direction A. Continue to push the push rod, and the support rod 102 continues to unfold along direction A. Figure 5 At this time, the anchoring barb 104 is turned about 90 degrees and is nearly perpendicular to the push rod. The push rod continues to apply a pushing force to completely push the anchoring plate 101 out of the sheath tube 115, and the support rod 102 continues to expand along direction A to form Figure 5 At this time, the anchor plate 101 is fully unfolded, and the anchor thorn 104 is turned about 90 degrees, located outside the anchor plate 101, facing the oblique outside direction of the central end 107, and piercing the inner wall of the left atrial appendage. It is fixed in the left atrial appendage cavity.

[0089] The process of retrieving the anchor plate 101 is opposite to the various stages of the process of pushing the anchor plate 101 out of the sheath tube 115. The anchor plate 101 is pulled into the sheath tube 115 by the push rod along direction B. The significant feature is that the anchor thorn 104 is turned from the oblique outer direction toward the central end 107 when unfolded to the opposite oblique inner direction toward the central end 107. This process ensures that the anchor thorn 104 will not scratch the left atrial appendage wall and can smoothly enter the sheath tube 115. The left atrial appendage occluder of this embodiment can not only ensure the repeatable positioning function of the anchor plate 101 in the left atrial appendage, but also greatly reduce the damage of the instrument to the left atrial appendage wall, reducing the risks and complications of surgery.

[0090] Example 7 A processing and specific implementation scheme

[0091] like Figure 1 , Figure 2 and Figure 3As shown, the left atrial appendage occluder involved in the present invention includes an occluding disk 106, an anchoring disk 101 connected to the occluding disk 106, wherein the occluding disk 106 is woven into a woven mesh with nickel-titanium wire, heat-treated into a disk shape, and fixed at both ends with steel sleeves 109 and bolt heads 110, one end of the occluding disk 106 is connected to the anchoring disk 101 with a steel sleeve, and the other end is provided with a thread and connected to the push rod of the conveying device. The diameter of the occluding disk 106 is about 2-6 mm larger than the anchoring disk 101, and a chemically modified PET flow-blocking film 108 is sutured inside the occluding disk 106. The anchoring disk 101 is a plurality of support rods 102 cut from a nickel-titanium tube, which are heat-treated into the shape shown in the figure using a mold. The central end 107 of the anchoring disk 101 is connected to the occluding disk 106 by welding. The number of support rods can be changed according to the actual mechanical properties and specifications. The support rod is issued from one side of the circle of the central end 107, spans the center of the central end 107 to the opposite side of the circle, and is curved, and multiple support rods are arranged together in a cross-radial shape. A hole can also be set on the support rod 102 for suturing a PET flow-blocking film on the anchoring disk 101 to prevent the outflow of thrombus in the left atrial appendage. On the support rod 102, the shape of the anchoring thorn 104 is cut out by laser, and the angle of the anchoring thorn 104 is fixed by heat treatment of the mold. The anchoring thorn 104 opens outward, toward the direction of the occlusion disk 106, and the root of the anchoring thorn 104 is on the support rod 102. The anchoring thorn 104 automatically opens outward without pressure, and the anchoring thorn 104 can be recovered to the support rod 102 when compressed. The end 102a of the support rod 102 is curved inward. A spherical round head 111 can be set at the end of the support rod 102, and the anchoring disk 101 is placed to pierce the inside of the atrial appendage when the sheath is pushed out.

[0092] Example 8

[0093] The PET flow-blocking membrane sutured in the occlusion disk of the left atrial appendage occluder of the present invention is a chemically modified flow-blocking membrane. Figure 6 As shown, the chemical modification of the flow-blocking membrane utilizes the reaction of replacing the ester group with the amide group, and grafting a molecule with a sodium sulfonate group on one side onto the surface of the flow-blocking membrane. The specific operation is as follows:

[0094] Place 50 tablets (50×50 mm 2 )PET flow barrier film, add 200mL of water / 1,4-dioxane (5:1) mixed solvent, add 0.5g of alkane with primary amine and sulfonic acid ends, such as 3-aminopropane sulfonic acid, 4-aminobutane sulfonic acid, 5-aminopentane sulfonic acid or 6-aminohexane sulfonic acid. Then add 1g of catalyst, such as sodium hydroxide, potassium hydroxide, ammonia water. Stir at 50-100 degrees Celsius for 2-8 hours. After the reaction is completed, take out the flow barrier film and repeatedly wash it with deionized water and anhydrous alcohol for 5 times.

[0095] refer to Figure 7 As shown, the PET flow-blocking membrane after the reaction was immersed in the positively charged dye toluidine blue and then taken out immediately. Multiple experiments found that the PET flow-blocking membrane that had not been chemically modified did not adsorb the positively charged dye toluidine blue. After the PET flow-blocking membrane was chemically modified for a gradually increasing time, the amount of the positively charged dye toluidine blue adsorbed also gradually increased.

[0096] Combination Figure 8 and Fig. 9 The contact angle test results shown in the figure show that the contact angle between the chemically modified PET flow-blocking membrane and the water droplet is 76.5±3 degrees (shown in the PET-8h bar graph), which is 41 degrees smaller than the contact angle of the unmodified PET flow-blocking membrane and 51 degrees smaller than the contact angle of the super-hydrophobic ePTFE membrane. From the test results, the hydrophilicity of the modified PET flow-blocking membrane is greatly enhanced. It is beneficial to improve the hydrophilicity and biocompatibility of the flow-blocking membrane, achieve rapid endothelialization, and reduce the risk of thrombosis associated with the occluder.

[0097] Example 9 Animal Experiment

[0098] The occluder with the chemically modified PET flow-blocking membrane according to the embodiment of the present invention is used, and the experimental method is as follows:

[0099] All experimental dogs underwent percutaneous left atrial appendage occlusion under general anesthesia. Fasting began 12 hours before the operation. After anesthesia, the dogs were tied to the operating table, intubated and connected to a ventilator for mechanical ventilation, and a transesophageal ultrasound probe was placed. The dogs were connected to an ECG monitor, and a venous access was established in the left lower limb. If the transesophageal echocardiogram showed abnormal cardiac anatomy in the dog, the operation was stopped and another experimental dog was replaced. For dogs with normal cardiac anatomy, the morphology of the left atrial appendage was observed by transesophageal echocardiography and the diameter of the left atrial appendage opening was measured. Based on this, an occluder that was about 15-35% larger than the measured diameter was selected. Routine disinfection and draping were performed, and the right femoral artery and vein were punctured using a Terumo puncture kit, and a 6F femoral sheath was placed. A 5F pigtail catheter was sent to the aortic sinus bottom through the femoral artery sheath to mark the position of the aortic sinus to avoid accidental puncture of the aortic sinus during atrial septal puncture. The atrial septal puncture needle (SL1, St Jude Medical, US) and its matching atrial septal puncture sheath were inserted through the femoral vein sheath, and the atrial septal puncture was completed under the guidance of transesophageal echocardiography. After the puncture was successful, 80-100U / kg heparin was given, the atrial septal puncture needle was withdrawn, and the long exchange wire was inserted into the left pulmonary vein. The 8-10F occluder delivery sheath was exchanged to the left atrial appendage opening. The pigtail catheter was sent to the left atrial appendage for left atrial appendage angiography and the diameter of the left atrial appendage opening was measured. Combined with the results of transesophageal echocardiography, an occluder umbrella that was about 15-35% larger than the measured value was selected, and the occlusion strategy was determined according to the lobular morphology of the left atrial appendage. The selected occluder umbrella was fixed to the head of the push rod through the nut, the air in the occluder and the delivery sheath was exhausted, and the push rod was slowly pushed forward to push part of the fixed disk out of the delivery sheath outside the left atrial appendage opening. The delivery sheath and the push rod are pushed as a whole to the left atrial appendage anchoring area. After the tip reaches the left atrial appendage opening anchoring area, the push rod is fixed and the delivery sheath is slowly withdrawn. After the occluder is deployed, it is observed by transesophageal ultrasound and left atrial appendage angiography. A push-pull test is performed to determine whether the occluder is firmly fixed. If the occluder is in the right position and firmly fixed, the occluder is released. If it fails to be completely blocked or the occluder is not well deployed, it can be completely retracted into the delivery sheath and the occluder can be deployed again. The occluder is released after the occlusion effect is ideal. After surgery, the experimental dogs routinely take aspirin and are followed up regularly. Anatomical images 1 day and 1 month after surgery ( Fig.10 a and 10b) show that the epithelial cells are uniformly endothelialized in the occluder within 1-2 months, and there is no obvious thrombosis, which has significantly better effects in endothelialization and thrombosis inhibition than the existing technology.

[0100] Therefore, the present invention has the following advantages:

[0101] The anchoring plate of the left atrial appendage occluder of the present invention is in a concave shape, which is helpful for retracting and releasing the anchoring plate with the sheath of the delivery device. When the occluder is pushed out and / or recovered by the sheath, the diameter of the anchoring plate in the concave shape during the contraction process is no larger than the diameter when it is opened, and it can be slowly reduced to enter the sheath of the delivery device, thereby avoiding damage to the left atrial appendage and improving safety and efficiency of use.

[0102] The anchoring plate structure of the left atrial appendage occluder of the present invention has a soft and stable deformation and excellent fatigue resistance for permanent implantation, and can adapt to left atrial appendage cavities of various shapes and sizes.

[0103] The two-stage design of the left atrial appendage occluder of the present invention enables the occluder to adapt to left atrial appendage cavities of various shapes and sizes.

[0104] The left atrial appendage occluder of the present invention can simultaneously have the advantages of stable anchoring and effective occlusion of the left atrial appendage.

[0105] The left atrial appendage occluder of the present invention can be used not only to occlude a single-leaf left atrial appendage, but also to occlude a double-leaf left atrial appendage.

[0106] The left atrial appendage occluder of the present invention can be repeatedly positioned. In some cases, if the placement effect is not good, in the absence of a release delivery device such as a delivery push rod, the occluder can be retracted into the sheath, and repeatedly positioned and placed until a satisfactory anchoring and occlusion effect is achieved, thereby greatly reducing the risk of surgery.

[0107] The left atrial appendage occluder of the present invention can use a smaller delivery system, further reducing the damage to the blood vessels caused by the delivery device during the operation.

[0108] The flexible connection between the left atrial appendage occluder and the push rod of the present invention greatly reduces the tension applied by the push rod to the occluder during surgery, so that the position of the occluder is more accurate.

[0109] The flow-blocking membrane of the left atrial appendage occluder of the present invention undergoes surface chemical treatment to render the surface negatively ionized, which not only reduces platelet adhesion on the surface of the occluder disk, but also improves the hydrophilicity and biocompatibility of the flow-blocking membrane, enables rapid endothelialization, and reduces the risk of thrombosis associated with the occluder.

[0110] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A left atrial appendage occluder, characterized in that: It includes a blocking plate and an anchor plate connected to the blocking plate. The anchor plate includes a plurality of support rods arranged at one end of a tubular component, wherein the support rods have a proximal end and a distal end, wherein the proximal end of the support rod is fixed to the tubular component and extends from the proximal end to a direction away from the tubular component, and then extends toward the tubular component to the distal end after being bent. Furthermore, the proximal end of the support rod spans across the center of the tubular component to the opposite side, and a plurality of the support rods are arranged in a cross-radial manner to form a concave anchor plate.

2. The left atrial appendage occluder according to claim 1, characterized in that: The portion of each support rod extending away from the tubular component forms a depression of the anchor plate, and the portion of each support rod extending toward the tubular component forms the periphery of the anchor plate. The distal end of the anchor plate is concave along with the depression shape.

3. The left atrial appendage occluder according to claim 1 or 2, characterized in that: The diameter of the depression of the anchor disc is close to the diameter of the anchor disc, and / or the axial length of the central depression of the anchor disc is close to the height of the anchor disc.

4. The left atrial appendage occluder according to claim 1, characterized in that: When the occluder is pushed out and / or retrieved by the sheath, the diameter of the anchoring disc in the concave shape during the contraction process is not greater than the diameter during the expansion process.

5. The left atrial appendage occluder according to claim 1, characterized in that: The support rod extends from one side of the circle at the end of the tubular component, crosses the center of the end, extends obliquely upward to the opposite side of the circle, and then extends downward in a curved shape.

6. The left atrial appendage occluder according to claim 5, characterized in that: The plurality of support rods constituting the anchor plate are cut from a nickel-titanium tube and are formed.

7. The left atrial appendage occluder according to claim 1, characterized in that: The plurality of support rods converge at an intersection of the tubular component away from the outer side of the occluding disk, and continue to extend away from the convergent position.

8. The left atrial appendage occluder according to claim 7, characterized in that: The plurality of support rods converge toward the central axis of the tubular component, cross each other at the convergence point, and then disperse to the surroundings.

9. The left atrial appendage occluder according to claim 1, characterized in that: The number of the support rods is an odd number and is selected between 2-50.

10. The left atrial appendage occluder according to claim 1, characterized in that: The occluding disk is a braided mesh made of nickel-titanium alloy wires, which is heat-treated into a disk shape, with its distal end fixed to the other end of the tubular component and its proximal end fixed with a bolt head.

11. The left atrial appendage occluder according to claim 1, characterized in that: The angle α between the proximal end of the support rod and the central axis of the tubular component is 40-55 degrees.

12. The left atrial appendage occluder according to claim 1, characterized in that: The support rod is provided with anchoring thorns. When the anchoring plate is unfolded, the anchoring plate is against the inner wall of the left atrial appendage, and the anchoring thorns pierce the inner wall of the left atrial appendage to stabilize the fixation of the anchoring plate in the left atrial appendage.

13. The left atrial appendage occluder according to claim 1 or 12, characterized in that: The support rod is also provided with a hole for suturing the flow-blocking membrane on the anchor plate.

14. The left atrial appendage occluder according to claim 1, characterized in that: When the occluding disc and the anchoring disc are unfolded, the height of the entire occluding device is 12-20 mm, the height of the anchoring disc is 9-15 mm, and the height of the occluding disc is 3-5 mm.

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