CN108926371B - Left auricle plugging device with closed-loop structure and assembly method thereof - Google Patents

Abstract

The present invention discloses a left atrial appendage occluder with a closed-loop structure and an assembly method thereof. The left atrial appendage occluder includes a sealing portion and an anchoring portion that are connected to each other, the sealing portion and the anchoring portion are pressed against each other, the anchoring portion is formed by cutting, and the distal side of the anchoring portion before release is a closed-loop structure. The left atrial appendage occluder of the present invention improves the shape of the end of the anchoring portion (the end away from the sealing portion before release) to prevent the end from being tangled and to facilitate multiple releases. Further, the connection method between the sealing portion and the anchoring portion is improved, which can avoid and delay the overall axial lengthening of the left atrial appendage occluder, and further ensure that the sealing portion adheres to and blocks the left atrial appendage opening.

Description

A closed-loop left atrial appendage occluder and an assembly method thereof

Technical Field

The invention relates to medical devices, and in particular to an interventional treatment device for occluding a left atrial appendage.

Background technique

Atrial fibrillation (AF) is the most common persistent arrhythmia. The incidence of AF increases with age, reaching 10% in people over 75 years old. During AF, the frequency of atrial excitation reaches 300-600 beats/minute, the heart rate is often fast and irregular, and the atrium loses its effective contraction function. During AF, the contraction force of the left atrial appendage decreases. In addition, the morphological characteristics of the left atrial appendage itself and the uneven trabeculae inside it cause eddies and slow flow in the blood flow in the left atrial appendage, which promotes thrombosis. More than 90% of left atrial thrombi in patients with non-valvular atrial fibrillation are present in the left atrial appendage. After the thrombus breaks off, it will enter the cerebral arteries through the aorta to form cerebral embolism, i.e. stroke.

In order to prevent and treat the risk of stroke in patients with atrial fibrillation, three methods are currently used in clinical practice, namely anticoagulant therapy, surgical treatment and percutaneous left atrial appendage occlusion therapy. Anticoagulant therapy refers to inhibiting blood coagulation by taking anticoagulants. Clinical trials have shown that anticoagulant therapy can significantly reduce the incidence of stroke, but anticoagulant therapy is a long process and also has obvious complications. Surgical treatment includes surgical resection or suturing of the left atrial appendage, but surgical surgery is traumatic and is generally performed during other operations such as valve replacement or coronary artery bypass grafting. Patients generally find it difficult to accept simple left atrial appendage surgery, especially elderly patients. Percutaneous left atrial appendage occlusion therapy refers to the use of a small diameter delivery sheath to deliver a left atrial appendage occluder to the left atrial appendage located in the right atrium of the heart through percutaneous puncture and release it, thereby achieving the purpose of preventing atrial fibrillation thromboembolism. Since 2001, percutaneous left atrial appendage occlusion therapy has been put into use, and animal experiments and clinical trials have been carried out. From a structural perspective, there are two main types of left atrial appendage occluders on the market: plug structure and double-disc structure.

The left atrial appendage occluder of the double-disc structure is usually composed of a sealing part and an anchoring part. After release, the sealing part blocks the left atrial appendage opening position, and the anchoring part is released inside the left atrial appendage and has barbs, which plays a role in fixing the sealing part. After release, the sealing part of the left atrial appendage occluder should be closely fitted at the left atrial appendage opening position to block the left atrial appendage mouth. If the sealing part cannot be closely fitted with the left atrial appendage mouth, it may cause the sealing part to be suspended in the left atrium, and the effect of effectively blocking the left atrial appendage mouth can not be effectively achieved, and the risk of thrombosis may be further increased. And a major factor that causes the sealing part to be unable to be effectively attached to the left atrial appendage mouth position is related to the connection mode between the sealing part and the anchoring part, that is: the anchoring part and the sealing part cannot be compactly connected together, the overall length of the product is long, and the anchoring part is radially compressed after release, which further increases the overall length of the product after release, and can cause the axial distance between the sealing part and the anchoring part to increase at the same time. After the sealing part is released, it cannot be effectively attached to the left atrial appendage mouth, causing residual shunt.

In the existing double-disc structure of the left atrial appendage occluder, the structure of the anchoring portion is generally woven into a mesh structure and cut into a rod shape. For the anchoring portion of the woven mesh structure, since the wires used in the weaving process will partially cross and overlap, the size of the delivery sheath required for the anchoring portion of the woven mesh structure is often larger than that of the cut structure under the same conditions; and for the cut rod-shaped anchoring portion, since the ends of the rod-shaped structure are relatively separated and suspended, there is a risk that the end of the support body is easily tangled during the process of being retracted into the sheath and then pushed out of the sheath again, which may cause the anchoring portion to be unable to unfold normally. In the prior art, a coating constraint is often set at the end of the support body, and the increase of the coating will increase the diameter of the sheath used.

Summary of the invention

The present invention provides a left atrial appendage occluder, which improves the shape of the end of the anchoring part (the end away from the sealing part before release) to prevent the end from being tangled and to facilitate multiple releases. Further, the connection mode between the sealing part and the anchoring part is improved, which can avoid and delay the overall axial lengthening of the left atrial appendage occluder, and further ensure that the sealing part adheres to and blocks the left atrial appendage opening.

A left atrial appendage occluder with a closed-loop structure comprises a sealing part and an anchoring part connected to each other, wherein the sealing part and the anchoring part are pressed against each other, the anchoring part is formed by cutting, and the distal end side of the anchoring part before release is a closed-loop structure.

The mutual pressing of the sealing part and the anchoring part can be understood as at least a part of the anchoring part and the sealing part are in contact with each other, and due to the pressing force, the sealing part is deformed.

The anchoring part adopts a plurality of supporting bars, which form a mesh structure through multiple intersections and bifurcations. The mesh structure can be either regularly distributed cells or irregular cells. As for each cell, its periphery is surrounded by supporting bars.

The distal end of the anchoring portion before release adopts a closed-loop structure, that is, there is no isolated, single end of the support bar. Generally, the ends of two adjacent support bars are intersected and connected to each other to form a V-shaped or U-shaped structure.

The closed-loop structure can eliminate the risk of tangling at the end of the anchoring portion, ensuring smooth deployment of the anchoring portion.

The anchoring part of the present invention adopts a support strip with a closed-loop structure at the distal end before release, which is easier to release than a denser anchoring net structure that is cut.

The ends of the denser anchoring net structure are interconnected and intersected to form mutual constraints. During the release process, the ends of the cutting net pull each other to form a very large constraint. Therefore, when released, the ends will present a trumpet mouth extending forward, making it impossible to roll up the anchoring net, resulting in failure to successfully release the anchoring part.

In the present invention, the sealing part and the anchoring part are compactly connected by applying a pre-tightening force, so that the occluder can better adhere to and block the left atrial appendage opening after being released, and even if the anchoring part or the sealing part is radially compressed and lengthened, the sealing part and the anchoring part can still be kept close to each other to ensure the sealing effect. The left atrial appendage occluder of the present invention can effectively improve the sealing performance and reduce the residual shunt.

At least one flow-blocking film is arranged in the sealing part, and the sealing part is a wireframe structure formed by cutting or a mesh structure formed by weaving. In the present invention, one or more flow-blocking films are arranged in the sealing part; and the periphery of the anchoring part can also be coated, such as coating all or part of the outer surface of the anchoring part.

The end of the anchoring portion mentioned in the present invention refers to the end of the anchoring portion away from the sealing portion before it is released, that is, when it is in a compressed state or the left atrial appendage occluder is compressed in the delivery device. This state is called a compressed state or a pre-release state; the state of the left atrial appendage occluder after it is released and expanded in the body can also be called a released (post) state or an expanded state.

Unless otherwise specified, the shapes of the sealing portion and the anchoring portion described in the present invention may be understood as being in a released state.

The distal end of the present invention refers to the end away from the operator during surgery, and the distal end and the proximal end are relative concepts. Limited by the release operation of the present invention and the physiological structure characteristics of the left atrial appendage, the anchoring part is at the distal end of the sealing part, and the corresponding orientation relationship is similar.

The sealing part is processed by weaving or cutting. The sealing part can adopt a regular or irregular mesh structure. When adopting the mesh structure, a skeleton can be set at an appropriate position as needed to improve the strength. The skeleton can have an increased cross-sectional area relative to other parts, or at least have a higher strength. The mesh structure can have regular or irregular cells, preferably diamond-shaped or nearly diamond-shaped cells, which can at least be compressed in the radial direction to facilitate recovery and release. The mesh structure has an obvious warp and weft structure, and the intersection of the warp and weft can be a fixed node. A non-fixed method can also be adopted, that is, the warp and weft can be dislocated and slipped to provide compliance and deformation ability.

Optionally, the sealing portion is a sealing disk or a sealing plug.

The "disc" and "plug" here are understood to refer to the approximate shape characteristics, for example, the disc is flat, and the shape of its outer edge basically conforms to the physiological structure characteristics of the left atrial appendage, such as round or other shapes based on actual needs.

For example, the plug is in a columnar shape with a certain thickness, such as an approximate cylinder, a truncated cone, etc., but the shape of its periphery and generatrix is not strictly limited. On the one hand, it can refer to the existing technology, and on the other hand, it can also be based on actual needs. The shape of the sealing part itself is not the focus of improvement of the present invention. Of course, the present invention also provides preferred or improved solutions.

Preferably, the sealing portion is a sealing disk having a predetermined forming state in which it is not in contact with the anchoring portion and a pressed state in which it is in contact with the anchoring portion; relative to the predetermined forming state, the middle portion of the sealing disk in the pressed state has a deformation axially protruding toward the anchoring portion.

Preferably, the sealing portion includes a disk surface facing away from the anchoring portion, a disk bottom facing the anchoring portion, and a waist connecting the disk surface and the disk bottom, wherein the disk bottom is flat or the middle of the disk bottom is convex toward one side of the anchoring portion or the middle of the disk bottom is convex away from the side of the anchoring portion.

The disk surface, disk bottom and waist constitute a cage structure as a whole. One or more flow-blocking membranes can be arranged inside the cage structure. The cage structure can be closed or partially open except for necessary hollow parts. When weaving the sealing part, there can be a convergent end on the disk bottom and the disk surface.

Since the cage structure has a certain space inside, it can ensure the sealing effect even if there is a certain deformation, which is particularly suitable for the feature of being tightly pressed against the anchoring part in the present invention. The diameter of the cage structure is mainly the diameter of the waist and the diameter of the anchoring part, while the disk diameter is slightly larger than the diameter of the waist to improve the sealing effect of the end.

Preferably, the diameter of the waist is substantially equal to or slightly larger than the diameter of the anchoring portion, and flow-blocking membranes are provided on the disk surface and in the waist.

The waist has a sufficient outer diameter so that it can come into contact with the inner cavity of the left atrial appendage when in use, and cooperate with the disk surface to form a double sealing effect.

Optionally, the sealing portion has a predetermined forming state in which it is not in contact with the anchoring portion and a pressed state in which it is in contact with the anchoring portion. In the predetermined forming state, the diameter of the disk surface is greater than the diameter of the disk bottom.

The diameter of the disk surface or the disk bottom described here can be approximately circular. If it is other shapes, it can be understood as the relative relationship between the cross-sectional area or the overall thickness. Taking the circle as an example, since the diameter of the disk surface is larger than the diameter of the disk bottom, the overall shape is a truncated cone, with a slightly larger top surface at the top, which converges more downwards, and a slightly smaller bottom surface at the bottom, so that when it is in contact with the anchoring part, it can fit the anchoring part in a conforming manner.

Optionally, the sealing portion has a predetermined forming state in which it is not in contact with the anchoring portion and a pressed state in which it is in contact with the anchoring portion. Relative to the predetermined forming state, the sealing portion in the pressed state has deformation at the waist and/or the bottom of the disc.

The pre-formed state refers to the shape obtained by heat setting after the sealing part itself is processed without assembly or external force. After assembly, it is pressed against the anchoring part, and in order to increase or maintain the pre-tightening force, it is deformed after being pressed against the anchoring part.

Optionally, relative to the predetermined forming state, the sealing portion in the pressed state has a radially contracted deformation at the waist.

When the sealing part and the anchoring part are separated from each other or radially compressed, the radial contraction deformation can offset or delay the axial extension trend to ensure the sealing of the left atrial appendage opening. The radial contraction deformation can make the waist produce a certain taper, and better fit with the left atrial appendage to improve the sealing effect.

Optionally, relative to the predetermined forming state, the sealing portion in the pressed state has a deformation at the bottom of the disc that is axially protruding toward the anchoring portion.

In a similar principle, the deformation of the axial protrusion toward the anchoring portion can also offset or delay the overall axial extension of the left atrial appendage occluder, and keep the sealing portion and the anchoring portion close to each other as much as possible to ensure the sealing effect.

Optionally, the sealing part abuts against the anchoring part at least at the outer edge of the disc bottom. Under the same preload force, the outer edge of the disc bottom abuts against the anchoring part to obtain a larger deformation of the sealing part, which is more conducive to compensating and offsetting the axial extension.

Optionally, the anchoring portion is formed by cutting a tube; the mesh structure is a hexagonal grid or a diamond grid structure or a combination of a hexagonal grid and a diamond grid.

Optionally, the tube is made of nickel-titanium alloy.

The mesh structure facilitates radial compression, loading and in vivo delivery, that is, the mesh structure itself is not strictly limited, and hexagons, diamonds or a combination thereof are preferred. In addition, the mesh structure as a whole can also be segmented. Taking the state before release as an example, the axial direction can be divided into multiple sections according to the structural characteristics. For each section, a grid structure with interlaced longitude and latitude or obvious cell form is adopted, and axially extending connecting rods are used between adjacent sections.

Optionally, the side of the sealing portion facing the anchoring portion is the bottom, and one end of the tube is provided with an annular connecting portion, and the connecting portion is connected to the bottom of the sealing portion.

Optionally, the connecting portion and the rest of the anchoring portion are an integral structure or separate structures fixed to each other;

The bottom of the sealing portion is converged and passes through the connecting portion, and an axial limiting portion limited by the connecting portion is provided on the passing portion.

The connecting part is an annular structure, and its central area is convenient for partial extension and penetration of the bottom of the sealing part. When the connecting part and the rest of the anchoring part are an integral structure, the rest of the anchoring part is cut, and one end is reserved at the end portion and not cut, and this portion serves as the connecting part. In addition, the connecting part can also be a split structure, which is fixedly connected to the rest of the anchoring part by welding, hooking or binding.

Optionally, the anchoring portion extends from the connecting portion away from the sealing portion to form an extension section, and the side of the extension section away from the connecting portion is turned outward to the bottom of the sealing portion to form a folded section, and the folded section is folded inward at the bottom position of the sealing portion to form a closed section, and the closed section is against the bottom of the sealing portion.

The anchoring part is an outward-turned structure as a whole, and the return section surrounds the periphery of the extension section to form a double-layer structure. There is a certain space inside the double-layer structure, which can absorb and allow the anchoring part to deform after it is pressed against the sealing part, but does not weaken its anchoring effect.

The closing section generally extends radially inwards and contacts the bottom of the sealing portion, which is more conducive to applying a pre-tightening force.

Optionally, the closing section is suspended on the periphery of the extending section, or is connected to the extending section.

"Suspended" means that there is no connection with the periphery of the extension section or it is only in contact with it. They can move freely relative to each other when they are deformed. If there is a connection, it can be a fixed connection or a sliding or rotating fit, which restricts the relative movement of the two to a certain extent.

Since the closing section is suspended on the periphery of the extension section, the anchoring portion can be straightened into a single-layer structure before release to facilitate loading into the sheath and recovery. When released, after the distal end of the anchoring portion is detached from the sheath, it has a tendency to flip toward the proximal end; as the release process proceeds, the distal end further rolls toward the proximal end; after the release is completed, the distal end rolls to the proximal end and the edge of the distal end remains in an open state.

Optionally, the extension section is conical, and its large end side (i.e., the side of the cone bottom) is far away from the connecting part and is open.

The extension section is trumpet-shaped for easy recovery, and the expanded opening can also improve the strength and stability of the structure.

The side of the anchoring part close to the sealing part is the proximal end, and the side away from the sealing part is the distal end. The connecting part is located between the proximal end and the distal end of the anchoring part. The axial distance between the connecting part and the proximal end of the anchoring part is L1, and the axial distance between the connecting part and the distal end of the anchoring part is L2; and L1 is greater than L2.

The connection part being away from the sealing part can save materials, and adopting a suitable inclination angle relative to the axial extension section of the anchor part is conducive to improving the radial stability after release. The axial midpoint of the connection part can be used as a reference point to measure the distances to both sides of the axial anchor part.

Optionally, the anchoring portion has a predetermined forming state in which it is not pressed against the sealing portion and a pressed state in which it is in contact with the sealing portion. In the predetermined forming state, the connecting portion is farther away from the sealing portion than the closing section in the axial direction of the anchoring portion. Relative to the predetermined forming state, in the pressed state, the connecting portion is closer to the sealing portion relative to the closing section in the axial direction of the anchoring portion.

That is, when the sealing part and the anchoring part are relatively close, the closing section contacts the bottom of the sealing part first. Since the connection part between the sealing part and the anchoring part is still some distance away from the sealing part, this distance also leaves space and possibility for further pulling to form preload.

The distal end of the anchoring portion before release corresponds to the inner edge of the closing section after release. The closing section includes a plurality of spaced-apart abutting claws, each of which is distributed around the axis of the anchoring portion and abuts against the sealing portion.

In order to ensure relatively stable abutment between the anchoring portion and the sealing portion, the abutment claws should be sufficient in number and distributed circumferentially.

Preferably, the abutment is a hollow structure with only a frame, so that a smaller radial dimension can be obtained before release, that is, in a preferred solution, the abutment has no supporting structure inside except its own frame, so that it is easier to compress.

Optionally, there are at least four claws, each claw is a closed-loop structure on the side facing the inner edge of the closing section, and is connected to the return section on the side facing the outer edge of the closing section.

The closed-loop structure here refers to the aforementioned "the distal end side of the anchoring portion before release is a closed-loop structure" to avoid sharp thorns or isolated endpoints.

Preferably, the number of the abutting claws is at least six, and more preferably, the number of the abutting claws is seven to nine.

Each claw includes two first support bars, one end of which intersects at the inner edge of the closing section, and the intersection is V-shaped or U-shaped, and the other end of the two first support bars extends to the outer edge of the closing section and intersects with the return section.

The V-shape or U-shape is only the approximate shape of the end of the claw, indicating the tendency of intersection. When the intersection is V-shaped, it is preferred to grind the intersection end into a rounded structure.

The side of each claw facing the inner edge of the closing section is further away from the sealing portion than the side facing the outer edge of the closing section.

That is, the extension direction of the claw is not along the radial direction of the anchoring part, but slightly inclined, the closer to the axis of the anchoring part, the farther away from the sealing part. Since the end of the claw is far away from the sealing part, the position where each claw abuts against the sealing part is close to the outer edge of the closing section.

In order to better guide the release of the anchoring portion and avoid bruising the inner wall of the body cavity, preferably, the portion where each claw is connected to the return section is an arc transition.

Adjacent claws are independent of each other at the closing section.

Adjacent claws are independent of each other and do not form a cross-linked structure, so that the end of the anchoring part has a certain amount of room for movement when flipped, and can be restored to a structure bent toward the connecting part when released from the sheath, thereby completing the release smoothly.

The folding section has a unit grid structure. In the released state, the first apex of each unit grid faces the sealing portion. The first support bars extending from each first vertex are grouped in pairs. The two first support bars in the same group extend and intersect to form one of the claws.

The first support bar constituting the claw extends from the vertex of the unit grid of the return section, and the regular unit grid structure is arranged along the circumferential direction, so that the mechanical properties of each part are roughly equivalent. As far as each unit grid is concerned, its shape is not strictly limited.

Preferably, the unit grid is a hexagonal grid structure or a diamond grid structure or a combination of a hexagonal grid structure and a diamond grid structure.

Preferably, the extension section is composed of a plurality of radially distributed second support bars, one end of each second support bar intersects with the connecting portion, and the other end extends to the return section.

The folding section has a unit grid structure. In the released state, the second apex of each unit grid of the folding section faces away from the sealing portion, and each second support bar extends and intersects at the corresponding second apex.

In the first support bar, the second support bar, the first vertex and the second vertex described in the present invention, "first" and "second" are only used to distinguish different locations and do not make additional limitations on the structural characteristics of the support bar or the vertex itself.

When the second support strips extend toward the second vertex, the adjacent second support strips are independent of each other. Since there is no cross-linking structure and the second support strips are independent of each other, it is easier to radially compress and flip and release.

Optionally, in the axial direction of the anchoring portion, the unit grid of the return segment is one row, two rows or three rows.

Preferably, in the axial direction of the anchoring portion, the unit grids of the return section are in a row, and the intersection of adjacent unit grids is in the middle of the return section, namely the intersection, and two adjacent claws meet for the first time at the intersection.

Similarly, two adjacent second support bars extend outward from the connecting portion and meet for the first time at the intersecting portion.

The intersection is located in the middle of the return section, so that adjacent first support strips and adjacent second support strips are independent of each other before extending to the intersection, and have greater freedom to adapt to the inner wall of the left atrial appendage with different structural characteristics.

The intersection is preferably a straight line segment. For example, if a hexagonal grid structure is used, the intersection of two adjacent unit grids is a straight line segment.

Optionally, barbs are provided on the outer side of the intersection.

Optionally, in the unit grid structure, the crossing angle of two support bars at the intersection is 20°-70°.

Because the support bars are in a compressed state in the radial direction before release, and the support bars gather toward the center, the crossing angle of the two support bars at the intersection generally refers to the released state.

Optionally, the width of the support strips forming the mesh structure of the anchoring portion is 0.18-0.3 mm.

The support bar here generally refers to the anchoring part, and of course also includes the first support bar and the second support bar.

Optionally, barbs are provided on the outer side of the anchoring portion.

The barbs can stably maintain the position of the left atrial appendage occluder in the left atrial appendage. In the case of a membrane, the barbs penetrate the membrane and extend to the outside.

Optionally, the barb and the anchoring portion are an integral structure.

That is, the barbs are also cut, and as a part of the support strip, the support strip can be cut and penetrated at the location where the barbs are formed, for example, a straight cut is made on the side of the support strip, or a V-shaped cut is made in the middle of the horizontal direction of the support strip.

The barbs are distributed at multiple locations around the anchoring portion.

In the axial direction of the anchoring portion, each barb is located in the middle of the anchoring portion.

Optionally, the bottom of the sealing portion is converged and passes through the connecting portion, and an axial limiting portion restricted by the connecting portion is provided on the passing portion.

If the sealing part is a woven mesh structure, the wires used for weaving the sealing part are gathered together at the bottom of the sealing part. This gathering is reflected as a structural feature and also includes the corresponding steps during processing, that is, gathering multiple wires into a bundle.

If the sealing portion is a wireframe structure formed by cutting the pipe, the end of the pipe of the sealing portion can be used as a gathering part.

Optionally, the axial limiting portion is an anti-slip head that is clamped and fixed on the outer periphery of the sealing portion.

The outer diameter of the anti-slip head is larger than the inner diameter of the connecting portion, so that the sealing portion is limited to a state of being in contact with the anchoring portion and necessary pre-tightening force can be maintained.

The anti-detachment head can be made of stainless steel, nickel-titanium alloy or other metal materials that meet the requirements of biocompatibility. The left atrial appendage occluder of the present invention is delivered to the position of the left atrial appendage of the heart through a delivery sheath by percutaneous puncture to block the left atrial appendage to prevent the risk of thrombosis in the left atrial appendage of patients with atrial fibrillation and thus causing stroke.

Preferably, the return section comprises a plurality of unit grids arranged circumferentially, each unit grid having endpoints at both ends of the anchoring portion in the axial direction, support bars are connected at the endpoints, and each support bar is bent in a corresponding direction to form an extension section and a closing section respectively.

As a further preference, the return segment includes at least one complete unit grid in the axial direction.

The present invention adopts a unit grid structure in the return section, and there is at least one complete row in the axial direction, which can provide a stronger radial supporting force and a more uniform force distribution.

If a complete row of cell structures is not formed in the reentrant segment, there may be a large strength difference between the distal and proximal ends of the reentrant segment. Of course, the possibility of use in specific environments is not ruled out.

Preferably, in the extension section, the support bars extend independently from each other and converge at the connecting portion.

Preferably, the anchoring portion has a pressing portion pressed against the sealing portion, the anchoring portion is a cylindrical structure in a compressed state, and the pressing portion is located on the inner wall side of the cylindrical structure.

Preferably, the anchoring portion is a cylindrical structure in a compressed state, and the inner wall side of the cylindrical structure abuts against the sealing portion in a released state.

After release, since the anchoring portion is rolled outward, the abutting portion originally located on the inner wall side is located on the outer side and faces the sealing portion after rolling, and abuts against the sealing portion.

In the compressed state, if the pressed part is on the outer wall side of the cylindrical structure, a more complicated rolling method is required, otherwise it is difficult to obtain a large outer diameter at the anchoring part to support and anchor the inner wall of the left atrial appendage.

However, by adopting a complex rolling form, the tendency of the anchoring end (the distal end in the compressed state) to expand outward when released can be changed, thereby avoiding puncturing the inner wall of the left atrial appendage and relatively improving safety.

Preferably, the anchoring portion and the sealing portion are in direct contact and tight contact in use.

Under normal use conditions, the anchoring part and the sealing part may be in direct contact and tight contact, but direct contact and tight contact are not the only use conditions. Under the influence of special physiological structures or after a period of use, the anchoring part and the sealing part may also move away from each other or even have a gap.

Preferably, the sealing portion is a double-layer structure, wherein the bottom layer is facing the anchoring portion, and the top layer is facing away from the anchoring portion, and the sealing portion is connected to the anchoring portion through the bottom layer.

The opposite situation is that the anchoring portion partially passes through the sealing portion and is connected to the top of the sealing portion. In the present invention, the anchoring portion is connected to the bottom of the sealing portion. When the anchoring portion and the sealing portion are pressed against each other, it is easier to obtain pre-deformation of the sealing portion, or in other words, it has a higher deformation acquisition efficiency.

As a further preference, one or more flow-blocking films are provided inside the double-layer structure.

Since the sealing part is more likely to loosen and stretch in the axial direction when it adopts a double-layer structure, the present invention is also preferably applicable to the sealing part of the double-layer structure. Whether it is a disc or a column, it can be regarded as a double-layer structure, and a flow-blocking membrane is built in. Preferably, the anchoring part and the sealing part are split structures; the anchoring part and the sealing part are pressed against each other during the assembly process.

The split structure is used, and the parts are heat treated and shaped separately before assembly. During the assembly process, the pre-deformation effect after tightening can be obtained. If an integrated structure is used, the tightening effect can also be obtained, but since there is no assembly process, the tightening effect needs to be obtained after heat setting. Therefore, higher requirements are placed on the heat setting process. Generally, the anchoring part and the sealing part need to be heat treated separately, which increases the difficulty of processing.

In order to obtain better supporting and anchoring effects, the anchoring parts are continuously distributed in the circumferential direction.

Although there will be gaps in the axial direction of the mesh or rod-like structure, the overall structure and distribution should be continuously distributed in the axial direction to achieve more uniform force distribution and stable support, and avoid relying solely on local support in the circumferential direction.

Preferably, the portion where the anchor portion abuts against the sealing portion is adjacent to an outer edge of the anchor portion.

Preferably, the location where the sealing portion abuts against the anchoring portion is adjacent to an outer edge of the sealing portion.

The abutment of the outer edges makes it easier to obtain axial deformation or radial convergence, thereby increasing the deformation under the same force.

Preferably, the sealing part and the anchoring part are assembled after heat setting, and during assembly, the sealing part and the anchoring part are in a first state of initial contact;

The connection portion between the sealing portion and the anchoring portion also has a second state after moving toward each other in the axial direction by a predetermined distance.

In the first state, the sealing part and the anchoring part have just been in contact. Since both the sealing part and the anchoring part have been heat-set, if the two further move toward each other along the axial direction, one of them will be deformed and maintain the stress caused by the deformation in the second state.

Preferably, the connection parts between the sealing part and the anchoring part are respectively located in the middle of the two parts in the radial direction, and in the first state, the sealing part and the anchoring part are in contact with each other in the peripheral area of the connection parts.

The above-mentioned stress is also the source of the preload force. If heat setting is performed after assembly without heat setting before, the stress will disappear during the heat treatment and the required preload force cannot be generated.

Therefore, it is necessary to emphasize that, in the second state, the sealing portion and the anchoring portion obtain the relative positional relationship after assembly, and no heat treatment is performed after the second state.

Since the anchoring part has better rigidity, the general stress is mainly generated from the deformation of the sealing part.

Preferably, compared with the first state, in the second state, the portion of the sealing portion connected to the anchoring portion is closer to the anchoring portion.

When entering the second state, the distance that the connection portion between the sealing portion and the anchoring portion moves toward each other in the axial direction affects the magnitude of the stress, so it needs to be expressed in an adaptive manner and controlled accordingly during assembly.

Preferably, the predetermined distance is expressed as:

Axial force at the connection between the seal and the anchor; or

The pressure at the contact point between the sealing part and the anchoring part; or

The deformation amount of the part of the sealing part connected to the anchor part.

The deformation amount is the axial change amount of the predetermined position of the sealing part, or the angle between the predetermined position of the sealing part and the axis of the sealing part.

The predetermined sealing portion is a portion where deformation occurs when the first state changes to the second state. For ease of expression and measurement, a portion with a relatively large deformation amount can be selected. For example, the predetermined sealing portion is a portion where the sealing portion contacts the anchor portion in the first state.

During assembly, the change in the expression of the predetermined distance can be detected to correspond to the obtained stress magnitude.

If the above-mentioned stress does not exist, even if the sealing part and the anchoring part are partially in contact during assembly, when the left atrial appendage occluder is axially stretched as a whole during use, that is, the sealing part and the anchoring part are separated from each other, the intrinsic restoring force between the sealing part and the anchoring part is relatively small, and only the elasticity of their respective materials is relied upon to overcome the overall axial stretching.

In the present invention, by first heat setting and then assembling and retaining the axial stress during assembly, the overall axial elongation of the left atrial appendage occluder can be better overcome during subsequent use, and the restoring force is improved by superposition of the elasticity and pre-tightening force of the sealing part and the anchoring part material, thereby ensuring the occluding effect of long-term use.

The present invention also provides a method for assembling the closed-loop structure left atrial appendage occluder, wherein the sealing part and the anchoring part are assembled after the heat setting is completed, and the sealing part and the anchoring part are close to each other and are in a first state when they are initially in contact during assembly; based on the first state, the connection part between the sealing part and the anchoring part moves toward each other along the axial direction for a predetermined distance to reach a second state;

The connection parts between the sealing part and the anchoring part are fixed to each other so that the connection parts are kept in the second state to complete the assembly.

Since the sealing part and the anchoring part are partially in contact with each other in the first state, when the first state is transformed into the second state, the axial position between the sealing part as a whole and the anchoring part may not change, and only the stress is generated by the local deformation.

The present invention achieves a compact connection between the sealing part and the anchoring part by improving the connection method, and maintaining a certain pre-tightening force can make the sealing part adhere to the left atrial appendage more closely and block the left atrial appendage opening, so as to reduce the incidence of internal leakage and residual shunt. In addition, the closed-loop structure at the end of the anchoring part further improves safety and is more convenient for recovery and release.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a sealing portion of a left atrial appendage occluder of the present invention before assembly;

FIG2a is a schematic diagram of the anchoring portion of the left atrial appendage occluder of the present invention before assembly;

FIG2b is a schematic diagram of the anchoring portion in FIG2a from another angle;

FIG3 is a schematic diagram of the connection process between the sealing part and the anchoring part;

FIG4 is a schematic diagram of the assembled left atrial appendage occluder of the present invention;

FIG5 is a schematic diagram of a left atrial appendage occluder in Example 2;

FIG6 is a schematic diagram of a left atrial appendage occluder in Example 3;

7a to 7c are schematic diagrams of the release process of the left atrial appendage occluder of the present invention;

Fig. 7d is an enlarged view of part A in Fig. 7c;

8a to 8d are schematic diagrams of the release state process of the anchoring portion in the left atrial appendage occluder of the present invention;

9 to 11 are schematic diagrams of the anchoring portion release process in Example 4, in which the sealing portion is shown in a released state;

12 to 14 are schematic diagrams of sealing portions with different dish bottom shapes in Example 4;

15 to 19 are comparative schematic diagrams of the bottom of the plate before and after deformation in Example 4;

20 to 22 are comparative schematic diagrams of another shape of the bottom of the dish before and after deformation in Example 4;

23 and 24 are comparative schematic diagrams of the bottom of the plate before and after deformation in Example 5;

25 to 34 are schematic diagrams of different connection methods before and after assembly in Example 6.

Detailed ways

Example 1

As shown in Fig. 1, the sealing part 1 of the left atrial appendage occluder of the present invention is woven with nickel-titanium wire, and the sealing part 1 includes a disk surface 11, a waist 12 and a disk bottom 14, and a plug head 13 is provided at the end of the disk surface for connecting a delivery device. The sealing part 1 is a cage-shaped structure with a certain internal space as a whole. In the pre-formed state, the waist 12 is roughly cylindrical, and a layer of flow-blocking film (omitted in the figure) is sewn in the disk surface 11, the axial middle area of the waist 12 and the disk bottom 14 respectively.

Before the sealing part 1 and the anchoring part 2 are connected, they are shaped by high-temperature heat treatment of a mold. After the heat treatment, the sealing part 1 has a nickel-titanium wire 15 with a distal contraction treatment.

As shown in Figures 2a and 2b, the anchoring portion 2 is formed by cutting a tube, and the central portion is an uncut portion reserved during cutting, which serves as a connecting portion 21. The cut portion of the anchoring portion extends radially outward from the connecting portion 21 and away from the sealing portion to form a mesh-conical extension section 22. The outer periphery of the extension section 22 is folded toward one side of the sealing portion to form a return section 23. The return section 23 extends to the bottom of the disk adjacent to the sealing portion, and the extension section 22 and the return section 23 are connected to each other through a circular arc transition portion 24.

The folded section 23 is bent inwardly near the sealing portion and extends toward the axis of the anchoring portion to form a closing section 25 . The folded section 23 and the closing section 25 are connected to each other via a circular arc transition portion 26 .

The extension section 22 constitutes an inner layer mesh structure, the return section 23 constitutes an outer layer mesh structure, and the closing section 25 is suspended at the periphery of the connecting portion 21 .

For example: the extension section is a plurality of rod-like structures that are radially spread out; the return section 23 includes axially distributed longitudinal support bars (i.e., the longitudinal support bars are arranged along the axial direction of the anchoring portion), and a plurality of longitudinal support bars are arranged in sequence along the circumferential direction, and each longitudinal support bar is interconnected by a circumferential connecting rod.

In the released state, in the axial direction of the anchoring portion, the circumferential connecting rods may be arranged in one or more rows. When there is only one row of circumferential connecting rods, the circumferential connecting rods and the longitudinal support bars form multiple units of an open-loop structure.

When there are multiple rows of circumferential connecting rods, there are multiple unit grids between adjacent rows of circumferential connecting rods and each longitudinal support strip to form a closed loop structure. The unit grid is a hexagon or a quadrilateral. At this time, it can be understood that the return section 23 is a mesh structure composed of longitudinal support strips and circumferential connecting rods.

In order to prevent the tip of the circumferential connecting rod from forming a spike and piercing the left atrial appendage wall, a support bar can be led out at the turning point of the connecting rod and connected with the closing section or the extension section accordingly, as shown in Figures 3 and 4.

3 and 4 , the anchoring portion 2 is a mesh structure as a whole. In the released state, the axial midpoint of the connecting portion 21 is used as a reference point, and its axial distance from the proximal end of the anchoring portion is L1, and its axial distance from the distal end of the anchoring portion is L2; and L1 is greater than L2.

The return section 23 is arranged with a row of hexagonal unit grids along the axial direction, such as the adjacent unit grids 30, 31 and 32 in the figure, and a straight line segment-shaped intersection 39 (longitudinal support bar) is between the two unit grids.

The extension section 22 includes a plurality of support bars extending radially from the connection portion 21, such as adjacent support bars 36 and support bars 37. According to the orientation of FIG3, each support bar radiates radially from the connection portion and slightly sinks and then bends upward until the support bar 36 is connected to the bottom vertex of the unit grid 31, and the support bar 37 is connected to the bottom vertex of the unit grid 32. One end of the support bar 36 and the support bar 37 are connected through the connection portion 21, and the other end passes through the unit grid 31 and the unit grid 32 until they reach the intersection between the unit grid 31 and the unit grid 32, and then they intersect with each other. Before that, they are independent of each other and have a large degree of freedom. The closing section 25 can be directly connected to the support bar of the extension section, or it can be connected to the support bar of the extension section through a circumferential connecting rod. As shown in Figures 3 and 4, the closing section 25 includes a plurality of claws arranged circumferentially (to avoid view interference, the claws on the rear side are omitted in Figure 3, and the same applies to other related figures), each claw is a frame structure surrounded by two support bars, for example, support bar 33 and support bar 34 intersect at end point 35 at the end of the anchoring portion, and the portion adjacent to end point 35 is a V-shaped structure, that is, a closed-loop structure is formed.

The other ends of the support bars 33 and 34 extend until they are connected to the top vertices of the unit grids 31 and 32. On the left side of the support bar 33 is another adjacent claw 38. The claws where the support bar 33 is located are independent of each other at the closing section, that is, no cross-linking is formed. The support bars of the two claws do not meet for the first time until they extend to the intersection 39 between the unit grids 30 and 31.

Barbs 4 are provided on the outside of each intersection to stabilize the position of the anchoring portion. Each barb 4 and the intersection where it is located (the intersection itself can also be regarded as one of the support strips or a part of the support strip) are an integral structure.

The width of the support strips at each anchoring portion is 0.18-0.3 mm, and the angles of the intersection and bifurcation of the support strips are 20°-70°. For example, the angles of the intersection and bifurcation of the top and bottom of the intersection 39 are 20°-70°.

In this embodiment, there are 8 claws, and each claw is farther away from the sealing part toward the inner edge of the closing section 25 than toward the outer edge of the closing section 25. After assembly, the position where each claw abuts against the sealing part is adjacent to the outer edge of the closing section 25.

During installation, the nickel-titanium wire 15 of the sealing part 1 is passed through the annular connecting part 21, and a certain pulling force is applied to tightly connect the sealing part 1 and the anchoring part 2. The bottom 14 and the closing section 25 are pressed against each other to form a certain pre-tightening force, and the sealing part is deformed by this pre-tightening force, and the overall height of the left atrial appendage occluder can be reduced. The deformation of the sealing part can be:

A portion of the disc bottom 14 is pulled by the nickel-titanium wire 15 to bulge toward the anchoring portion;

A portion of the bottom 14 of the plate is deformed by the pressure of the anchoring portion 2 and at the same time pulls the diameter of the side of the waist 12 adjacent to the anchoring portion 2 to shrink.

After tightening, the excess part of the nickel-titanium wire 15 is cut off, and a steel sleeve 16 (equivalent to an anti-slip head) is welded or installed on the end to achieve axial limitation with the connecting part 21.

When the steel sleeve 16 is used, the steel sleeve 16 is slid and pressed against the distal end of the connecting portion 21 and then clamped and fixed. The steel sleeve 16 can be made of stainless steel, nickel-titanium alloy or other metal materials that meet the biocompatibility requirements. In this embodiment, stainless steel is selected.

Since the nickel-titanium wire 15 passes through the inside of the annular connecting portion 21, the two are staggered inside and outside, that is, they are interlaced and connected with each other, and cross each other's end parts. Looking along the axial direction of the left atrial appendage occluder, the nickel-titanium wire 15 of the connecting portion 21 and the sealing portion 1 (equivalent to the connecting portion of the sealing portion) are nested with each other, and their respective extension paths are straight lines, that is, they extend along the axial direction of the left atrial appendage occluder. Due to the staggered arrangement, there is no spatial interference when each extends, and the distance between the sealing portion 1 and the anchoring portion 2 can be shortened as much as possible until the two are pressed against each other in the peripheral area of the occluder axis.

During the assembly process, when the sealing part 1 and the anchoring part 2 are close to each other, the moment they just touch can be regarded as the first state. As the nickel-titanium wire 15 is further pulled axially, the side of the sealing part 1 facing the anchoring part 2 will gradually press against the anchoring part 2 to generate stress, i.e., pre-tightening force. After the nickel-titanium wire 15 is pulled axially a predetermined distance, it reaches the second state. At this time, the sealing part 1 and the anchoring part 2 are maintained in the second state by the steel sleeve 16, i.e., the stress is maintained.

The predetermined axial pulling distance can be measured directly or expressed based on the shape change of the side of the sealing part 1 toward the anchoring part 2, i.e., the bottom 14 of the disk. The tension of the nickel-titanium wire 15 or the tension between the sealing part 1 and the anchoring part 2 can also be directly measured.

The shape change of the tray bottom 14 can refer to its own shape in the first state, and can also refer to the angle between the bottom 14 and the waist 12 or the axis of the sealing portion 1 in different states.

Example 2

Referring to Figure 5, the difference between this embodiment and embodiment 1 is only the shape of the sealing part 1. The sealing part is an inverted cone, and one or two layers of flow-blocking membranes are arranged inside. The middle part of the sealing part facing the anchoring part protrudes toward the anchoring part, and is tightly pressed against the anchoring part through the conical surface.

Example 3

Referring to Fig. 6, the difference between this embodiment and embodiment 1 is only the shape of the sealing portion 1. The sealing portion 1 is a flat disc, i.e., a sealing disc. The sealing disc has a double-layer structure and a flow-blocking membrane is arranged inside. Under the action of the pre-tightening force, the side of the sealing portion facing the anchoring portion is pressed against the anchoring portion.

Release process description

Referring to Figures 7a to 7d, and Figures 8a to 8d, taking the left atrial appendage occluder of Example 3 as an example, the release process is that the left atrial appendage occluder is connected to the operating handle through a steel cable 5, and a sheath 6 is provided on the external sliding sleeve of the steel cable 5. The left atrial appendage occluder is also received in the sheath 6 after being compressed.

The left atrial appendage occluder passes through the inferior vena cava 70, the right atrium 71, and the left atrium 72 in the direction of arrow B and enters the left atrial appendage 73, and then the sheath 6 is withdrawn, so that the compressed left atrial appendage occluder is gradually exposed and released, and the end of the anchoring part 2 is released first, and is rolled outward and backward while being released, until the anchoring part 2 is completely exposed outside the sheath 6 and rolled back to the shape obtained by the heat treatment.

After release, the extended section is at the distal end, the return section is in contact with the inner wall of the left atrial appendage and anchored by barbs, and although the closing section is released first, it is rolled toward the sealing part, so after release it is at the proximal end of the anchoring, that is, the side adjacent to the sealing part.

After the anchoring part 2 is released, the sheath 6 is further withdrawn, and the sealing part 1 is gradually exposed and released until the sealing part 1 is completely released, and then the steel cable 5 is detached from the left atrial appendage occluder, that is, the bolt head 13 at the end of the disk of the sealing part 1 is detached.

The pre-tightening force between the sealing part 1 and the anchoring part 2 in the present invention can make the sealing part and the left atrial appendage adhere more closely, so that the flow-blocking membrane in the sealing part can effectively block the blood flow into the left atrial appendage, thereby reducing the incidence of endoleakage.

Example 4

This embodiment focuses on illustrating the release of the anchoring portion and the change in shape of the sealing portion during the assembly process. The specific structures of the anchoring portion and the sealing portion can be combined with at least one of the other embodiments unless otherwise specified.

Referring to Figures 9 to 11, the left atrial appendage occluder in this embodiment includes a sealing portion 5100 and an anchoring portion 5200 that are interconnected. The anchoring portion 5200 is compressed in the sheath before release to facilitate its passage into the lesion site in the body. In the compressed state, the anchoring portion 5200 is cylindrical, and portion A is located on the inner wall of the cylinder. As the anchoring portion 5200 is rolled up and released (the rolling direction can be seen in the direction indicated by the arrow), portion A gradually turns outward from the inner wall of the cylinder and finally abuts against the bottom of the disk of the sealing portion 5100.

12 to 14 , the sealing portion 1100 includes a disk surface, a waist and a disk bottom 5110 , the central area of the disk bottom 5110 is converged to form a distal nickel-titanium wire 5120 , and the distal nickel-titanium wire 5120 passes through a connection portion 5210 of the anchoring portion (eg, in the form of a steel sleeve, etc.).

In different embodiments, the middle area of the bottom 5110 may be raised away from the anchoring portion, as shown in FIG. 12 ; the middle area of the bottom 5110 may be flat, as shown in FIG. 13 ; the middle area of the bottom 5110 may also be raised toward the anchoring portion, as shown in FIG. 14 .

The above are all shape characteristics of the disc bottom 5110 when it is not assembled, that is, when the pre-tightening force has not been applied. After the pre-tightening force is applied, the middle area of the disc bottom 5110 has different degrees of deformation, and generally moves closer to the anchoring part.

15 to 19 , taking one of the disc bottom shapes as an example, the sealing part and the anchoring part are individually processed and heat-treated to finalize their shapes before assembly begins. First, the distal nickel-titanium wire 5120 is passed through the connecting portion 5210 of the anchoring part so that the sealing part and the anchoring part are axially close to each other.

As shown in Figure 22, when the contact is just made and no preload force has been applied, it is the first state. At this time, the middle area C of the disc bottom 5110 tends to bulge away from the anchoring part, and then the distal nickel-titanium wire 5120 is pulled downward in the direction of the arrow in Figure 23, while the connecting part 5210 of the anchoring part moves upward relatively in the direction of the arrow. The middle area C is deformed by force until the predetermined deformation or preload force requirement is reached, and then the distal nickel-titanium wire 5120 is fixed by the anti-slip head 5130. At this time, it is the second state, as shown in Figure 24, and the middle area C is deformed by force and is basically in a flat bottom state.

In order to control the assembly process, the change in angle B or the axial change H of the middle area C can be monitored when the preload force is applied. The stress deformation of the middle area C can be more clearly reflected by comparing with Figure 19. The dotted line expresses the position of the middle area C in the first state.

Referring to Figures 20 to 22, in another embodiment, the sealing portion and the anchoring portion are in a first state when they have just come into contact and no preload force has been applied. At this time, the middle region C of the disk bottom 5110 tends to bulge away from the anchoring portion. During assembly, the distal nickel-titanium wire is pulled downward, while the connecting portion of the anchoring portion moves relatively upward. The middle region C is deformed by force until the predetermined deformation or preload force requirement is reached, and the distal nickel-titanium wire is fixed with the anti-slip head. This is the second state. When the middle region C is deformed by force, the waist of the sealing portion radially converges in the direction of the arrow in Figure 21. In the second state, the waist of the sealing portion and the bottom of the disk are in an inverted cone shape as a whole, which can be more clearly reflected by comparing with Figure 22. The dotted line expresses the position of the waist and the middle region C in the first state.

Example 5

23 and 24 , the left atrial appendage occluder in this embodiment includes a sealing portion 6100 and an anchoring portion 6200. In the first state, the sealing portion 6100 has an inverted cone-shaped bottom 6110 on one side facing the anchoring portion. The central area of the bottom 6110 converges to form a distal nickel-titanium wire 6120, and the distal nickel-titanium wire 6120 passes through a connecting portion 6210 (for example, in the form of a steel sleeve, etc.) of the anchoring portion 6200.

In the second state after assembly, the middle part of the disc bottom 6110 is further brought closer to the connection part 6210 and the taper is increased, and the distal nickel-titanium wire 6120 is locked in the axial position by the anti-slip head 6130.

Example 6

This embodiment focuses on illustrating different connection methods of the anchoring part and the sealing part. The specific structures of the anchoring part and the sealing part can be combined with at least one of the other embodiments unless otherwise specified.

In the attached drawings of this embodiment, the left atrial appendage occluder includes a sealing portion 7100 and an anchoring portion 7200 which are connected to each other. The sealing portion 7100 includes a disk surface, a waist portion and a disk bottom 7110 .

In Figures 25 and 26, the shape of the central area of the disc bottom 7110 converges to form a connecting portion, that is, the central area converges to form the distal nickel-titanium wire 7120, and the middle part of the anchoring part converges in shape as a whole to form a connecting portion, and its end is fixed by a connecting piece 7210 (for example, a steel sleeve). During assembly, the distal nickel-titanium wire 7120 passes through the hollow part of the connecting piece 7210 of the anchoring part and is relatively tightened to form a pre-tightening force. After the anchoring part and the sealing part are pressed against each other, the middle area of the disc bottom is deformed and further bulges toward the anchoring part. Finally, the distal nickel-titanium wire 7120 is fixed by an anti-slip head 7130 (for example, a steel hoop), and the excess part of the distal nickel-titanium wire 7120 is cut off to complete the assembly.

In another embodiment, referring to Figures 27 and 28, the shape of the central area of the disc bottom 7110 converges to form a connecting portion, that is, the central area converges to form the distal nickel-titanium wire 7120, and the middle part of the anchoring portion converges in shape as a whole, that is, it converges to form the proximal nickel-titanium wire 7220, and a connector 7210 with two channels arranged side by side is used to make the distal nickel-titanium wire 7120 and the proximal nickel-titanium wire 7220 pass through the corresponding channels in opposite directions and are relatively tightened to form a pre-tightening force, and after the anchoring portion and the sealing portion are pressed against each other, the middle area of the disc bottom is deformed and further protrudes toward the anchoring portion, and finally the distal nickel-titanium wire 7120 is fixed by an anti-slip head 7130 (for example, a steel hoop), and the excess portion of the distal nickel-titanium wire 7120 is cut off; the proximal nickel-titanium wire 7220 is fixed by an anti-slip head 7230 (for example, a steel hoop), and the excess portion of the proximal nickel-titanium wire 7220 is cut off to complete the assembly.

In another embodiment, referring to Figures 29 and 30, the shape of the central area of the disk bottom 7110 converges to form a connecting portion, the end of which is fixed by a connecting piece 7140 (for example, a steel sleeve), and the middle part of the anchoring portion converges in shape as a whole, that is, it is gathered to form a proximal nickel-titanium wire 7220. The proximal nickel-titanium wire 7220 passes through the hollow area of the connecting piece 7140 and is relatively tightened to form a pre-tightening force. After the anchoring portion and the sealing portion are pressed against each other, the middle area of the disk bottom is deformed and further bulges toward the anchoring portion. The proximal nickel-titanium wire 7220 is fixed by an anti-slip head 7230 (for example, a steel hoop), and then the excess part of the proximal nickel-titanium wire 7220 is cut off to complete the assembly.

In another embodiment, referring to FIG. 31 and FIG. 32 , the shape of the central area of the disk bottom 7110 converges to form a connecting portion, that is, the central area converges to form the distal nickel-titanium wire 7120 , and the middle part of the anchoring portion converges in shape as a whole, that is, converges to form the proximal nickel-titanium wire 7220 .

The distal nickel-titanium wire 7120 and the proximal nickel-titanium wire 7220 are directly connected, that is, the connecting parts are omitted. As can be seen in the figure, the proximal nickel-titanium wire 7220 is bolted and wrapped around the periphery of the distal nickel-titanium wire 7120, and an anti-slip head 7130 (for example, a steel hoop) can be provided at the end of the distal nickel-titanium wire 7120. The end of the proximal nickel-titanium wire 7220 can be fixed to the bottom of the disk of the sealing part by welding, and its spiral shape can also be pre-heat-set, and its elasticity can be overcome during winding to unfold and be re-wound around the periphery of the distal nickel-titanium wire 7120. Not only that, the distal nickel-titanium wire 7120 can also be spirally wound with the proximal nickel-titanium wire 7220.

In another embodiment, referring to FIG. 33 and FIG. 34 , the overall shape of the disk bottom 7110 converges to form a connecting portion, that is, the entirety is converged to form the distal nickel-titanium wire 7120, and the middle portion of the anchoring portion is overall convergent in shape to form a connecting portion, and its end is fixed by a connecting piece 7210 (for example, a steel sleeve). During assembly, the distal nickel-titanium wire 7120 passes through the hollow portion of the connecting piece 7210 of the anchoring portion and is relatively tightened to form a pre-tightening force, and finally the distal nickel-titanium wire 7120 is fixed by an anti-slip head 7130 (for example, a steel hoop), and then the excess portion of the distal nickel-titanium wire 7120 is cut off to complete the assembly.

The above disclosure is only a specific embodiment of the present invention, but the present invention is not limited thereto. Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Obviously, these changes and modifications should all fall within the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any special limitation to the present invention.

Claims (28)

1. The left auricle plugging device with the closed-loop structure comprises a sealing part and an anchoring part which are connected with each other, and is characterized in that the sealing part and the anchoring part are mutually abutted, and the distal end side of the anchoring part before release is in the closed-loop structure;

the anchoring part is formed by cutting a pipe;

the sealing part comprises a disk surface facing away from the anchoring part, a disk bottom facing towards the anchoring part and a waist part connecting the disk surface and the disk bottom;

the sealing part is propped against the anchoring part at least at the outer edge part of the disc bottom;

the abutting is that at least one part of the anchoring part and the sealing part are contacted with each other, and the sealing part is deformed due to the abutting force.

2. The left atrial appendage closure of claim 1, wherein the sealing portion is a sealing disk and has a pre-molded state in which it is not in contact with the anchoring portion and an abutting state in which it is in contact with the anchoring portion; the middle portion of the sealing disk in the abutted state has a deformation protruding axially toward the anchor portion with respect to the pre-molded state.

3. The left atrial appendage closure of claim 1, wherein the disk bottom is a flat bottom or a middle portion of the disk bottom is convex toward the anchor side or a middle portion of the disk bottom is convex away from the anchor side.

4. A left atrial appendage sealer of closed loop construction according to claim 3, wherein said sealing member has a pre-formed state in which it is not in contact with the anchoring member and a tightly-held state in which it is in contact with the anchoring member, the sealing member in the tightly-held state having a deformation at the waist and/or the disc bottom with respect to the pre-formed state.

5. The left atrial appendage closure of claim 1, wherein the sealing portion has a bottom portion on a side facing the anchoring portion, wherein the tubular member has an annular connecting portion at one end thereof, and wherein the connecting portion is connected to the bottom portion of the sealing portion.

6. The left atrial appendage closure of claim 5, wherein the connecting portion is integral with the remainder of the anchoring portion or is a separate structure secured to one another;

the bottom of the sealing part is convergent and penetrates through the connecting part, and an axial limiting part limited by the connecting part is arranged on the penetrating part.

7. The left atrial appendage closure of claim 5, wherein the anchoring portion extends away from the sealing portion at the junction to form an extension segment, wherein a side of the extension segment remote from the junction is folded outwardly back toward the bottom of the sealing portion to form a fold-back segment, wherein the fold-back segment folds inwardly at the bottom of the sealing portion to form a neck segment, and wherein the neck segment abuts against the bottom of the sealing portion.

8. The left atrial appendage closure of claim 7, wherein the side of the anchoring portion adjacent the sealing portion is proximal and the side distal from the sealing portion is distal, the connecting portion is positioned between the proximal and distal ends of the anchoring portion, the axial distance between the connecting portion and the proximal end of the anchoring portion is L1, and the axial distance between the connecting portion and the distal end of the anchoring portion is L2; and L1 is greater than L2.

9. The left atrial appendage closure of claim 7, wherein the anchoring portion has a pre-formed state in which the anchoring portion is not in abutment with the sealing portion and an abutment state in contact with the sealing portion, the connecting portion being further from the sealing portion than the necked-in section in an axial direction of the anchoring portion in the pre-formed state; in the abutting state, the connecting portion is further adjacent to the sealing portion with respect to the closing-in section in the axial direction of the anchoring portion with respect to the predetermined shape.

10. The left atrial appendage closure of claim 1, wherein the anchoring portion has a tightening portion that tightens against the sealing portion, the anchoring portion being of a cylindrical structure in a compressed state, and the tightening portion being on an inner wall side of the cylindrical structure.

11. The left atrial appendage closure of claim 7, wherein the distal end of the anchoring portion prior to release corresponds to an inner edge of the released closure segment, the closure segment comprising a plurality of spaced apart abutments, each abutment being disposed about the axis of the anchoring portion and abutting the sealing portion.

12. The left atrial appendage closure of claim 11, wherein the abutment is a hollowed-out structure having only a rim.

13. The left atrial appendage closure of claim 11, wherein the number of said fingers is at least four, each finger being closed loop toward the inner edge of the closure segment and being connected to said return segment toward the outer edge of the closure segment.

14. The left atrial appendage closure of claim 11, wherein each of the plurality of support fingers comprises two first support bars, one end of each of the two first support bars intersecting at an inner edge of the closed section, the intersection being V-shaped or U-shaped, and the other end of each of the two first support bars extending to an outer edge of the closed section and intersecting the return section.

15. The left atrial appendage closure of claim 11, wherein the side of each of the fingers facing the inner edge of the closure segment is further from the sealing portion than the side facing the outer edge of the closure segment.

16. The left atrial appendage closure of claim 11, wherein adjacent ones of the abutments are independent of one another at the convergent section.

17. The left atrial appendage closure of claim 14, wherein the reentrant section has a cellular lattice structure, first apexes of each cellular lattice in the released state facing the sealing portion, and first support bars extending from each first apex are in a group of two pairs, and two first support bars of the same group extend to intersect to form one of the support claws.

18. The closed loop structured left atrial appendage occluder of claim 17, wherein the cell lattice is a hexagonal lattice structure or a diamond lattice structure or a combination of hexagonal lattice structures and diamond lattice structures.

19. The left atrial appendage closure of claim 7, wherein the extension segment is comprised of a plurality of radially distributed second support struts, each second support strut intersecting the connection at one end and extending to the reentrant segment at the other end.

20. The left atrial appendage closure of claim 19, wherein the reentrant section has a cellular lattice structure, the second apices of each cellular lattice of the reentrant section facing away from the sealing portion in the released state, each second support bar extending and intersecting a respective second apex.

21. The closed loop left atrial appendage closure of claim 20, wherein said second support struts are independent of each other during extension to said second apex.

22. The left atrial appendage closure of claim 1, wherein the anchoring portion and the sealing portion are of a split construction; the anchoring portion and the sealing portion abut against each other during assembly.

23. The left atrial appendage closure of claim 22, wherein the sealing portion and the anchoring portion are assembled after heat setting, the sealing portion and the anchoring portion having a first state of initial contact during assembly;

the connecting part between the sealing part and the anchoring part also has a second state after the connecting part moves oppositely along the axial direction for a preset distance.

24. The left atrial appendage closure of claim 23, wherein the connection between the sealing portion and the anchoring portion is located radially intermediate the sealing portion and the anchoring portion, respectively, and wherein the sealing portion contacts the anchoring portion in a first state at a peripheral region of the connection.

25. The left atrial appendage sealer of claim 24, wherein the portion of the sealing member that is connected to the anchoring member in the second state is closer to the anchoring member than the first state.

26. The left atrial appendage closure of claim 23, wherein said predetermined distance is expressed in terms of:

axial force of the connection part between the sealing part and the anchoring part; or (b)

Pressure at the contact point between the sealing portion and the anchoring portion; or (b)

Deformation amount of the portion of the sealing portion connected to the anchor portion.

27. The left atrial appendage closure of claim 26, wherein the deformation is an axial change in the predetermined portion of the seal or an angle of the predetermined portion of the seal to the axis of the seal.

28. A method of assembling a left atrial appendage closure of closed loop construction of claim 1, wherein the sealing portion and the anchoring portion are assembled after heat setting, the sealing portion and the anchoring portion being brought into close proximity to each other during assembly and initially in contact with each other in a first state; on the basis of the first state, the connecting part between the sealing part and the anchoring part moves oppositely along the axial direction for a preset distance and then reaches the second state;

and fixing the connecting part between the sealing part and the anchoring part to each other, so that the connecting part is kept in the second state to complete assembly.