Left atrial appendage occluder

Abstract

The present application relates to the technical field of left atrial appendage occlusion by intervention, and discloses a left atrial appendage occlusion device, which comprises an elastically deformable occlusion component and a fixing component connected with the occlusion component, the fixing component comprises an elastically deformable frame structure composed of a plurality of support rods or braided wires, the frame structure has a concave distal end face on the side away from the occlusion component, a membrane piece is attached to the distal end face, the membrane piece covers at least the concave distal end face, and the membrane piece is connected and limited by a traction piece leading to the side of the occlusion component to enhance the safety and stability of the left atrial appendage occlusion device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of left atrial appendage occlusion by intervention, in particular to an implantable medical device for left atrial appendage occlusion. BACKGROUND

[0002] Left atrial appendage occlusion can be used for the treatment of non-valvular atrial fibrillation patients. Studies have shown that more than 90% of left atrial thrombus comes from the left atrial appendage. When atrial fibrillation occurs, the normal rhythm of the left atrium is disrupted, resulting in slower blood flow in the left atrium, and even slower blood flow in the left atrial appendage. Blood components are retained and coagulated to form thrombus. After left atrial appendage occlusion, the probability of atrial fibrillation embolism can be greatly reduced.

[0003] The left atrial appendage occlusion device can be implanted by intervention. It can be elastically compressed in a sheath tube, delivered to the atrial appendage through an intervention access, and released after deformation. The deformed left atrial appendage occlusion device can be fixed and occluded in the left atrial appendage. The left atrial appendage occlusion device usually has a fixed component and an occlusion component connected to each other but relatively independent. The former is placed in the atrial appendage lumen to fix the occlusion device in the left atrial appendage, and the latter is positioned at the atrial appendage opening by the former and achieves the occlusion effect. The existing design of such typical left atrial appendage occlusion devices is described in Chinese patents CN101795628A (AGA), CN202143640U (Xianjian), CN204814031U (Denuo), CN104856741A (Pulse), CN206120393U (Practical), and CN108472031A (Keaidun). Among them, the fixed component and the occlusion component can be selected as a frame of various shapes such as disc, dish, column, umbrella, trapezoid, etc. according to needs. The two frames can be a one-piece structure (for example, the occlusion device disclosed in CN101795628A is integrally woven by braided wire), or a two-piece connection structure.

[0004] Among them, the fixed component can be selected as a net-shaped frame structure woven by braided wire or a frame structure composed of multiple support rods arranged by laser cutting and shaping a pipe. Some fixed components have a concave at the distal end of their frame structure, for example, CN202143640U, CN104856741A and CN108472031A disclose an umbrella-shaped fixed disc structure with a central concave obtained by cutting support rods from a pipe and shaping. CN204814031U and CN206120393U disclose a distal face structure of the fixed component with a distal end central concave formed by braided wire. The fixed component can also be selected to be provided with a membrane, for example, to improve the occlusion ability of the left atrial appendage, maintain the stability of the frame shape, or reduce the friction requirement. Some membranes can also facilitate the growth of endothelial cells and accelerate the endothelialization of the occlusion device.

[0005] The part of the membrane member provided on the inner recess of the distal end of the fixation member usually directly covers the inner recess, however, the potential risk brought by this may not be considered. SUMMARY

[0006] The present application aims to provide an improved left atrial appendage occluder with enhanced safety and stability.

[0007] The left atrial appendage occluder of the present application comprises an elastically deformable occlusion member and a fixation member connected to the occlusion member, the fixation member comprises an elastically deformable frame structure made of a plurality of support rods or braided wires, the frame structure has a distal end face with an inner recess on the side away from the occlusion member, and a membrane member is attached to the inner recess of the distal end face, the membrane member covers at least the inner recess of the distal end face, and the membrane member is connected and limited by a traction member directed to the side of the occlusion member at the position corresponding to the inner recess.

[0008] When the fixation member is in the working state in the left atrial appendage, it is usually compressed and deformed to a certain extent by the pressure of the left atrial appendage, and its diameter becomes smaller. The inventors have found that when the left atrial appendage occluder is in the working state, the part of the membrane member covering the distal recess of the fixation member is prone to prolapse, and during the contraction and relaxation of the left atrial appendage, the prolapsed part of the membrane member swings with the reciprocating impact of the blood flow in the left atrial appendage cavity, which may be disadvantageous, for example, the prolapse may repeatedly rub against other parts of the membrane member or the frame, which may reduce the fatigue life of the membrane member and cause early rupture failure of the membrane member. In addition, the uncontrolled swinging of the prolapsed part of the membrane member may also provide additional undesirable traction to the frame of the fixation member, which may reduce the positioning ability of the frame in the left atrial appendage cavity.

[0009] In the embodiments of the present application, the traction member pulls the membrane member at the distal end of the fixation member to the side of the occlusion member, the swinging of the membrane member is limited by the traction, compared to not setting the traction member, the swinging amplitude and direction of the part of the membrane member covering the distal recess in the left atrial appendage cavity during the contraction or relaxation of the left atrial appendage are reduced, which is advantageous in many aspects, for example, the stability of the membrane member is improved, frequent and violent swinging is avoided to cause early rupture failure of the membrane member, the fatigue life of the membrane member is improved; for another example, the swinging amplitude and direction of the membrane member impacted by the blood flow are limited, the traction to the fixation frame is reduced, the influence on the positioning of the fixation frame in the left atrial appendage cavity is reduced, and the displacement or shedding of the fixation frame in the left atrial appendage cavity is reduced.

[0010] In some embodiments of the present application, the distal end face of the frame structure has a central inner recess, and the membrane member covers the distal end face of the frame structure.

[0011] In some other embodiments, the membrane member covers the distal end face of the frame structure and at least wraps the part of the frame structure adjacent to the outer periphery of the distal end face.

[0012] In some embodiments of the present application, in order to attach the membrane member to the frame structure, the membrane member can be fixed to the support rods or the braided wires of the frame structure at its edges.

[0013] Alternatively, the membrane member can be fixed to the support rods or the braided wires of the frame structure by lacing, adhesive bonding, welding or clamping.

[0014] Without being limited by the above, one skilled in the art can also select other ways to achieve the attachment of the membrane member to the frame structure.

[0015] In embodiments of the present application, the membrane member is limited by the traction member so that the membrane member is limited in shifting or deforming to the side away from the occlusion component.

[0016] In a preferred embodiment, the membrane member is limited by the traction member so that it is substantially not deformed by bulging to the side away from the occlusion component.

[0017] In a preferred embodiment, when the left atrial appendage occluder is in a non-constrained state, the membrane member is limited by the traction member so that it is substantially in a tensioned state.

[0018] In one embodiment of the present application, one end of the traction member is fixed to the occlusion component.

[0019] In some embodiments, the occlusion component is a mesh structure woven by braided wires, the occlusion component further comprises a fixing member for fixing the free ends of the braided wires, and a flow-blocking membrane fixed to the mesh structure, wherein the end of the traction member directed to the side of the occlusion component is fixed to the braided wires of the mesh structure of the occlusion component, or the fixing member, or the flow-blocking membrane.

[0020] In another embodiment of the present application, the end of the traction member directed to the side of the occlusion component is fixed to the proximal end of the fixing component.

[0021] In some embodiments, the fixing component comprises a frame structure woven by braided wires, the proximal end of the frame structure is provided with a proximal end member for bundling and fixing the proximal ends of the braided wires, and the end of the traction member directed to the side of the occlusion component is fixed to the proximal end member.

[0022] In some embodiments, the fixing component comprises a frame structure composed of support rods, the support rods converge at an end member at the proximal end of the fixing component, and the end of the traction member directed to the side of the occlusion component is fixed to the end member.

[0023] In some embodiments, the fixing member comprises a frame structure formed by a plurality of support rods arranged in crisscross manner, each support rod converges at a proximal end of the fixing member to an end member, and the support rods are arranged in crisscross manner to form an overlapping area adjacent to the end member, and one end of the pulling member directed to the side of the blocking member is fixed to the overlapping area.

[0024] In another embodiment of the present application, the blocking member and the fixing member are connected by a connecting body, the connecting body has a diameter smaller than that of the blocking member and the fixing member, and one end of the pulling member directed to the side of the blocking member is fixed to the connecting body.

[0025] The pulling member can be a single wire, or at least two wires formed by at least twice passing a wire through the membrane member.

[0026] In some embodiments, the diameter of the wire of the pulling member is greater than the thickness of the membrane member.

[0027] In some embodiments, the pulling member is a surgical suture, and the membrane member is a PET or PTFE material spunlace nonwoven fabric.

[0028] The left atrial appendage occluder of the present application can enhance the safety and stability of the left atrial appendage occluder after implantation by limiting the prolapse part of the membrane member through the pulling member. BRIEF DESCRIPTION OF DRAWINGS

[0029] The present application will be further described in detail below with reference to the accompanying drawings.

[0030] Figure 1 FIG. 1 is a schematic view showing a prior art left atrial appendage occluder placed in the left atrial appendage;

[0031] Figure 2 FIG. 2 is a schematic view showing the structure of the left atrial appendage occluder shown in FIG. 1; Figure 1

[0032] FIG. 3 is a schematic view showing the membrane member attached to a fixing member; Figure 3

[0033] FIG. 4 is a partial schematic view of the fixing member of another prior art left atrial appendage occluder, showing the distal end of the fixing member; Figure 4

[0034] FIG. 5 is a partial schematic view showing the fixing member of the left atrial appendage occluder shown in FIG. 4 fixed in the left atrial appendage cavity; Figure 5 Figure 4 FIG. 6 is a schematic view showing the structure of an embodiment of the left atrial appendage occluder of the present application;

[0035] Figure 6

[0036] Figure 7 ​​Structure schematic view of another embodiment of the left atrial appendage occluder of the present application;

[0037] Figure 8 Structure schematic view of another embodiment of the left atrial appendage occluder of the present application;

[0038] Figure 9 Structure schematic view of another embodiment of the left atrial appendage occluder of the present application;

[0039] Figure 10 Partial view of the fixing of the fixing component of an embodiment of the left atrial appendage occluder of the present application in the left atrial appendage cavity;

[0040] Figure 11 Partial view of the fixing of the fixing component of another embodiment of the left atrial appendage occluder of the present application in the left atrial appendage cavity.

[0041] In the above drawings, the following signs are explained as follows:

[0042] 1, fixing component; 11, inner recess; 12, membrane; 121, part of the membrane covering the inner recess; 13, support rod; 131, anchor spike;

[0043] 2, occluding component; 21, flow-blocking membrane; 3, connecting body; 4, atrial appendage wall; 5, traction component;

[0044] 61, first fixing point; 62, second fixing point. DETAILED DESCRIPTION

[0045] The present application will be further described in detail below in combination with the drawings and specific embodiments, but the present application is not limited thereto.

[0046] Reference Figure 1 Figure 1 shows a schematic view of the occlusion of the left atrial appendage by a left atrial appendage occluder of the prior art after the implantation of the left atrial appendage occluder into the left atrial appendage, the fixing component 1 being positioned in the atrial appendage cavity near the ostium of the atrial appendage, the proximal side of the fixing component 1 having the occluding component 2 connected thereto, the occluding component 2 being located at the ostium of the atrial appendage, isolating the left atrial appendage cavity from the left atrial cavity, and realizing the occlusion of the left atrial appendage. Figure 2 Figure 2 shows a schematic view of the fixing component 1 of the left atrial appendage occluder of the prior art, the plurality of support rods 13 being arranged in a cross shape to form the frame structure of the fixing component 1, the membrane 12 being located at the distal end of the fixing component and covering the support rods 13 constituting the frame of the fixing component 2, and being fixed by a plurality of fixing points, the distal end of the frame structure being formed with an inner recess at the position of the intersection of the support rods, and the inner recess being covered by the part 121 of the membrane. Figures 1-2 For more specific structure and preparation of the left atrial appendage occluder shown, reference can be made to Chinese patent CN108472031A, and the entire contents of which are incorporated herein.

[0047] Reference Figure 3In the illustrated embodiment, the membrane 12 is shown covering the distal end of the fixation member 1, where the fixation points can include two loops, a plurality of first fixation points 61 arranged in a circumferential loop around the frame of the fixation member 1, and a plurality of second fixation points 62 arranged on the distal face of the frame of the fixation member 2. The first fixation points 61 are located at or near the edge of the membrane. The second fixation points are not necessary, but are generally recommended to further reduce the relative sliding of the membrane with respect to the frame, to make the membrane compactly adhere to the frame. Thus, the above-described fixation of the membrane to the frame of the fixation member is a substantially passive connection, for example, the membrane 12 can be fixed to the frame structure by lacing, adhesive bonding, welding, or clamping. Without being limited thereto, those skilled in the art can also choose other ways to achieve the attachment and fixation of the membrane to the frame structure.

[0048] The frame of the fixation member 1 can also be optionally provided with anchor spikes 131, and the size of the membrane 12 can be selected not to extend to the anchor spikes 131, as shown in Figure 2 Another embodiment, the anchor spikes 131 can penetrate the membrane 12, as shown in Figure 3

[0049] Without being limited to Figures 1-3 The example of the fixation member 1 of the left atrial appendage occluder composed of a support rod, the fixation member 1 frame can also be woven into a disc-shaped, cylindrical or other shape by weaving wires, which is also a known technical means in the art.

[0050] Referring to Figure 4 , a woven body structure fixation member 1 is shown, which can be woven from a nickel-titanium alloy wire and heat treated to shape the frame, with a concave 11 at the center of the distal end of the frame, and the distal face of the frame is covered by a membrane 12, which can be fixed to the nickel-titanium alloy wire in contact with the membrane by the aforementioned loop of fixation points.

[0051] Whether the fixation member is a support rod or a woven wire frame, when placed in the working state in the atrial appendage, it is usually compressed and deformed to a certain extent by the compression of the atrial appendage, and it pulsates with the atrial appendage. Referring to Figure 4 and Figure 5 , Figure 5 The fixation member 1 is shown placed in the atrial appendage cavity, held in position by the compression of the atrial appendage wall within the atrial appendage cavity, relative to Figure 4 The unbound state shown in Figure 5 ​The fixed part 1 shown in the middle has a significant reduction in the compressed diameter. The amount of change in diameter can be about 5%-40% depending on the structure of the left atrial appendage occluder, the manufacturing process, and the selected size, for example, the diameter of some fixed parts with a woven frame structure can change by about 10%-30%, and the diameter of some fixed parts with a support rod frame structure can change by about 5%-25%, but it should be understood that the fixed part with a woven frame structure is not always more prone to diameter change under compression than the fixed part with a support rod frame structure. When the left atrial appendage occluder is in the working state, due to the reduction in the diameter of the fixed part, the part of the membrane covering the distal end of the inner recess of the fixed part is prone to prolapse, as shown in Figure 5 , which shows that the part 121 of the membrane covering the inner recess protrudes distally into the atrial cavity, but it should be understood that the prolapsed part of the membrane is not constrained in shape and can be randomly folded or protrude into the distal end of the frame.

[0052] Although the left atrial appendage occluder can achieve occlusion of the atrial appendage after implantation, during the initial occlusion period, for example, 1-3 months or longer, the blood occluded in the atrial cavity can still flow in the atrial appendage with the contraction and relaxation of the left atrial appendage. The prolapsed part of the membrane is then subjected to repeated impact from the blood flow in the atrial cavity, which causes the prolapsed part to swing uncontrollably and randomly, for example, the prolapse can contact other parts of the membrane or the frame, causing repeated friction, which can reduce the fatigue life of the membrane and cause early rupture of the membrane. In addition, the uncontrollable swinging of the prolapsed part of the membrane increases the instability of the left atrial appendage occluder, which in turn causes an undesirable additional pull on the frame of the fixed part, which can reduce the positioning ability of the frame in the atrial cavity.

[0053] Based on this, the left atrial appendage occluder of the embodiment of the present application connects and limits the distal membrane of the fixed part to the distal inner recess of the corresponding fixed frame by a traction member directed to one side of the occlusion part. Please refer to Figure 10 and Figure 11 , the distal end of the traction member 5 is attached to the part 121 of the membrane 12 covering the inner recess 11, and the proximal end of the traction member 5 is directed to one side of the occlusion part. When the left atrial appendage occluder is in the working state, the part 121 of the membrane covering the inner recess is limited by the traction member 5 and cannot protrude freely into the distal end of the atrial cavity. Please refer to Figure 10 , the part 121 of the membrane covering the inner recess is slightly folded due to the limitation, which is basically on the distal end surface of the frame of the fixed part 1, which makes it not protrude greatly into the distal end of the atrial cavity, so that the part 121 of the membrane covering the inner recess is basically not swung outside the frame of the fixed part 1, which significantly reduces the effect of the swinging of the membrane on the positioning of the fixed part. Please refer to Figure 11, showing another embodiment of the present application, in which the covered inner recess portion 121 of the membrane is bulged into the frame inner recess due to the traction of the traction member 5.

[0054] The traction of the membrane 12 by the traction member 5 can be based on the weight of the traction member 5 itself, for example, the other end of the traction member 5 can be not fixed but arranged to be directed to one side of the occlusion member 2.

[0055] However, in a preferred solution, the other end of the traction member 5 is fixed, so that the covered inner recess portion 121 of the membrane is moved or deformed to be restrained in a direction away from the occlusion member.

[0056] In some embodiments, the distance between the two ends of the traction member 5 in the axial direction of the LAA occluder can be variable, for example, when the LAA occluder is transformed from the un-restrained state to the working state, as the fixing member 1 and the occlusion member 2 are deformed under pressure, the fixing member 1 and / or the occlusion member 2 can increase in axial length while decreasing in diameter, for example, the proximal end and the distal end of the frame of the fixing member 1 move in different directions, when the other end of the traction member 5 is fixed to the proximal end of the frame of the fixing member 1, the traction member 5 can form an active traction of the covered inner recess portion 121 of the membrane to move or deform in the direction of the proximal end of the fixing member, forming a bulging inner recess, for example Figure 11 It is obvious that the other end of the traction member 5 is not limited to being fixed to the proximal end of the frame of the fixing member 1, but can also be fixed to the occlusion member 2, or, when there is a connecting body 3 between the fixing member 1 and the occlusion member 2, it can also be fixed to the connecting body 3.

[0057] The traction of the membrane at the fixing member by the traction member to the side of the occlusion member restrains the swinging of the membrane, compared to not having the traction member, the swinging amplitude and direction of the portion of the membrane covering the distal recess in the LAA cavity during the contraction or relaxation of the LAA is reduced, which is advantageous in many aspects, for example, improving the stability of the membrane, avoiding frequent and violent swinging that can cause early rupture and failure of the membrane, improving the fatigue life of the membrane; for another example, the swinging amplitude and direction of the membrane under the impact of blood flow is limited, reducing the pulling force on the fixed frame, reducing the impact on the positioning of the fixed frame in the LAA cavity, reducing the displacement or shedding of the fixed frame in the LAA cavity.

[0058] The following will describe in detail some specific embodiments of the LAA occluder of the present application.

[0059] Embodiment 1

[0060] Reference Figure 6, shows a left atrial appendage occluder, including a fixation component 1 and an occlusion component 2, the fixation component 1 includes a plurality of support rods 13, which can be cut from a nitinol tube and then expanded with a mold, and shaped into a disc shape with a distal end face diameter and a periphery by heat treatment as shown in Figure 6 The occlusion component 2 is made of nitinol wire by weaving into a woven mesh, and is shaped into a disc shape by heat treatment, and is fixed into a closed disc at both ends with a sleeve, and then a threaded connector for connecting a delivery device is welded on the sleeve at the proximal end, and the other end of the closed disc is a fixed end, and the sleeve of the fixed end is connected to the joint of the fixation component 1 to form a connecting body 3 to realize the connection between the fixation component 1 and the occlusion component 2, and a flow-blocking film (PTFE or PET film) is sewn inside the closed disc with medical sutures, which is not shown in the figure.

[0061] The fixation component 1 can have nine support rods 13, but other numbers such as six, eight, twelve, and sixteen can be selected according to mechanical properties and size specifications. The nine support rods 13 are radially symmetrically arranged, spread out in a umbrella shape along the diagonal axis from the center, and then bent into a U shape to make the ends of the support rods 13 substantially parallel to the central axis of the fixation component 1. Each support rod 13 converges to the joint of the fixation component 1. The joint is at the uncut end of the nitinol tube and is located at the center of the fixation component 1 to form a central end connected to the closed disc.

[0062] The distal end of the fixation component 1 is provided with a membrane 12, which covers the distal end face of the fixation component 1 with a central recess 11 and wraps around the outer periphery of the frame structure of the fixation component 1 adjacent to the distal end face. Referring to Figure 3 , the membrane 12 can be tied to the support rods 13 at a first fixing point 61 and a second fixing point 62 on the periphery. A surgical suture serves as a traction member 5, one end of which is tied to the part 121 of the membrane covering the recess, and the other end is tied to the woven wire on the distal disc face of the closed disc.

[0063] Example 2

[0064] Referring to Figure 7 , a left atrial appendage occluder is shown, which is different from example 1 in that the support rods of the fixation component 1 form a cross arrangement, which can be simultaneously referred to the foregoing and Figures 1-3 The support rods are arranged in a staggered overlapping position adjacent to the joint of the fixation component 1.

[0065] The distal end of the fixation component 1 is provided with a membrane 12, which covers the distal end face of the fixation component 1 with a central recess 11 and wraps around the outer periphery of the frame structure of the fixation component 1 adjacent to the distal end face. Referring to Figure 7A surgical suture is used as the traction member 5, one end of which is tied to the portion 121 of the membrane 12 covering the inner recess, and the other end is tied to the braided wire of the proximal end surface of the closed disc.

[0066] When the left atrial appendage occluder is in the unbound state, the membrane 12 can be in a substantially tensioned state or a loose state.

[0067] Embodiment 3

[0068] Reference Figure 8 , a left atrial appendage occluder is shown, which includes a fixed component 1 and an occlusion component 2, and a connecting body 3 connecting the fixed component 1 and the occlusion component 2. The fixed component 1 and the occlusion component 2 are respectively made of nickel-titanium wire by weaving into a woven mesh, and are made into a disc shape by heat treatment. The two ends of the disc of the occlusion component 2 are fixed by a sleeve to form a closed disc, and the two ends of the disc of the fixed component 1 are fixed by a sleeve to form an anchor disc. A threaded connecting piece connected with a delivery device is welded on the sleeve at the proximal end of the closed disc, and the other end of the sleeve of the closed disc is fixed with the proximal end sleeve of the anchor disc to form the connecting body 3. A medical suture is used to sew a flow-blocking membrane 21 inside the closed disc, which can be made of PTFE or PET membrane. The distal end of the anchor disc is shaped into an inner recess, and the sleeve of the braided wire at the distal end of the anchor disc can be located in the inner recess. In order to simplify the drawing, part of the sleeve of the disc is not shown.

[0069] The distal end of the anchor disc is provided with a membrane 12 covering the distal end surface of the fixed component 1 having a central inner recess 11. The membrane 12 can be tied to the braided wire at the distal end surface of the anchor disc by a line at one or two rings of fixing points close to the edge thereof. A surgical suture is used as the traction member 5, one end of which is tied to the portion 121 of the membrane covering the inner recess, and the other end is tied to the flow-blocking membrane 21 inside the closed disc.

[0070] Embodiment 4

[0071] Reference Figure 9 , a left atrial appendage occluder similar to embodiment 3 is shown, the distal end of the anchor disc is provided with a membrane 12 covering the distal end surface of the fixed component 1 having a central inner recess 11. The membrane 12 can be tied to the braided wire at the distal end surface of the anchor disc by a line at one or two rings of fixing points close to the edge thereof. A surgical suture is used as the traction member 5, one end of which is tied to the portion 121 of the membrane covering the inner recess, and the other end is tied to the braided wire of the proximal end surface of the closed disc.

[0072] Without limitation, in addition to the above embodiments, the fixing member and the blocking member can adopt various forms or structures known in the art, for example, the fixing member and the blocking member can be integrally woven, can have a woven mesh portion without a connecting body as a transition between the two members, the connecting body 3 is not necessary, in some embodiments, the fixing member 1 and the blocking member 2 are an integrally woven body structure, the fixing member 1 is directly connected to the blocking member 2 without a transition connecting body portion. Alternatively, in some embodiments, the woven wire of the fixing member can be fixed only by a steel sleeve at one end. In some embodiments, one end of the traction member can be fixed to the connecting body 3 or the steel sleeve of the fixed woven wire.

[0073] In the embodiments of the present application, the traction member 5 can be flexible, for example, relative to the support rod or the woven wire, but at the same time can have stronger rigidity relative to the film member 12, that is, the traction member 5 can be less deformable than the film member, for example, the diameter of the traction member is selected to be greater than the thickness of the film member, thereby the traction member 5 is loaded on the film member 12 to form a limit to the film member 12, which can reduce the free swing amplitude of the film member covering the concave portion 121. The traction member 5 can also be in a non-wire form, such as a columnar, block or strip material.

[0074] In some embodiments, the traction member can be selected as a surgical suture, and the film member is selected as PET or PTFE material, preferably as a spunlace non-woven fabric. The film member can be partially permeable to blood but not to larger emboli. The film member can be subjected to chemical or physical surface modification, such as increasing hydrophilicity, lubricity, etc.

[0075] In some embodiments, the distal concave portion 11 of the fixing member 1 of the left atrial appendage occluder has a distal end face occupying at least one fourth, or one third, or one half, or even a larger proportion of the radial cross-sectional area.

[0076] In the embodiments of the present application, the traction member pulls the film member at the fixing member towards the side where the blocking member is located, and the swing of the film member is limited by the traction, which at least reduces the swing amplitude and direction of the portion of the film member covering the distal concave portion in the left atrial appendage cavity during the contraction or dilation of the left atrial appendage, compared to the case without the traction member. This is advantageous in many aspects, for example, it improves the stability of the film member, avoids frequent and violent swing that leads to early rupture and failure of the film member, and improves the fatigue life of the film member; for another example, the swing amplitude and direction of the film member are reduced, which reduces the pulling force on the fixing frame, reduces the influence on the positioning of the fixing frame in the left atrial appendage cavity, and reduces the occurrence of displacement or shedding of the fixing frame in the left atrial appendage cavity.

Claims

1. A left atrial appendage occluder comprising an occlusion member elastically deformable and a fixation member connected to the occlusion member, the fixation member comprising an elastically deformable frame structure of a plurality of struts or braided wires, the frame structure having a distal end face with a concave portion on a side distal to the occlusion member, and a membrane attached to the distal end face, the membrane covering at least the concave portion of the distal end face, the membrane being connected and limited by a pulling member leading to the side distal to the occlusion member at a portion corresponding to the concave portion, the fixation member being compressed and deformed in a working state, the portion of the membrane covering the concave portion of the distal end face prolapsing, but the prolapsing portion being limited in oscillation amplitude and direction by the pulling member.

2. The left atrial appendage occluder of claim 1, wherein: The membrane covers the distal end face of the frame structure having a central concave portion.

3. The LAA occluder according to claim 1, characterized in that: The membrane covers the distal end face of the frame structure and at least wraps around a portion of the frame structure adjacent to the outer periphery of the distal end face.

4. The left atrial appendage occlusion device of any one of claims 1-3, wherein: The membrane is fixed to the struts or braided wires of the frame structure at its edges.

5. The LAA occluder according to claim 4, characterized in that: The membrane is fixed to the struts or braided wires of the frame structure by lacing, adhesive bonding, welding, or clamping.

6. The LAA occluder according to claim 1, characterized in that: The membrane is limited by the pulling member and does not bulge out to the side distal to the occlusion member.

7. The LAA occluder according to claim 1, characterized in that: The membrane is limited by the pulling member and is in a tensioned state when the left atrial appendage occluder is in an unbound state.

8. The LAA occluder according to claim 1, characterized in that: One end of the pulling member is fixed to the occlusion member.

9. The LAA occluder according to claim 8, characterized in that: The occlusion member is a mesh structure woven by braided wires, the occlusion member further comprising a fixing member for fixing free ends of the braided wires, and a flow blocking membrane fixed to the mesh structure, wherein the end of the pulling member leading to the side distal to the occlusion member is fixed to the braided wires of the mesh structure of the occlusion member, or the fixing member, or the flow blocking membrane.

10. The LAA occluder according to claim 1, characterized in that: The end of the pulling member leading to the side distal to the occlusion member is fixed to the proximal end of the fixation member.

11. The LAA occluder according to claim 10, characterized in that: The fixation member comprises a frame structure woven by braided wires, the proximal end of the frame structure being provided with a proximal end member that converges and fixes proximal ends of the braided wires, and the end of the pulling member leading to the side distal to the occlusion member is fixed to the proximal end member.

12. The LAA occluder according to claim 10, characterized in that: The fixation member comprises a frame structure of a plurality of struts, the struts converging at a terminal member at the proximal end of the fixation member, and the end of the pulling member leading to the side distal to the occlusion member is fixed to the terminal member.

13. The LAA occluder according to claim 10, characterized in that: The fixation member comprises a frame structure of a plurality of struts arranged in a cross pattern, the struts converging at a terminal member at the proximal end of the fixation member, and the struts are arranged in a cross pattern to form an overlapping portion adjacent to the terminal member, and the end of the pulling member leading to the side distal to the occlusion member is fixed to the overlapping portion.

14. The LAA occluder according to claim 1, characterized in that: The occlusion member and the fixation member are connected by a connecting body, the connecting body having a diameter smaller than that of the occlusion member and the fixation member, and the end of the pulling member leading to the side distal to the occlusion member is fixed to the connecting body.

15. The LAA occluder according to claim 1, characterized in that: The traction member is a single strand or at least two strands formed by at least twice passing a single strand through the film member, and the diameter of the strand of the traction member is greater than the thickness of the film member.

16. The LAA occluder according to claim 1, characterized in that: The traction member is a surgical suture, and the film member is a PET or PTFE material spunlace nonwoven fabric.

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