TECHNICAL FIELD

The present disclosure relates to the field of medical instruments, and in particular to an interventional treatment instrument for occluding a left atrial appendage (LAA).

BACKGROUND

Atrial fibrillation (AF) is the most common persistent arrhythmia. The incidence of AF increases with age and is up to 10% in people over 75 years old. When AF occurs, the atrial pulsation rate is up to 300-600 beats per minute. The heart rate is often fast and irregular, and an effective atrial systolic function is lost. In case of AF, the contractility of a left atrial appendage (LAA) is decreased; in addition, morphological characteristics of the LAA and the uneven trabecula in the LAA which make the blood flow generate an eddy in the LAA and the blood flow rate slow down, thus resulting in the formation of thrombus. For patients with nonvalvular AF, more than 90% of left atrium thrombi occur in the LAA, and after the thrombi fall off, the thrombi will enter the cerebral arterial blood vessels through the aorta, thereby causing cerebral embolism, namely stroke.

Currently, to prevent AF patients from the risk of stroke, preventive treatments are clinically performed by mainly utilizing the following three methods: anticoagulant treatment, surgical treatment, and percutaneous left atrial appendage occlusion (LAAO) treatment. The anticoagulant treatment is to restrain blood coagulation by oral anticoagulants, so as to reduce the risk of thrombus formation in the LAA, and then reduce the occurrence probability of stoke. Clinic trials show that the anticoagulant treatment can remarkably reduce the occurrence probability of stroke, but the anticoagulant treatment is a long-term process and also has remarkable complications, mainly including bleeding complications, and even may lead to severe cases. The surgical treatment includes surgical ablation or suture of LAA. However, surgical trauma is large, and such surgery is generally performed during the valve replacement surgery or the coronary artery bypass graft surgery. Patients, especially elderly patients, generally are hard to accept a simple LAA surgery. The percutaneous LAAO treatment is to deliver and then release a LAA occluder to the LAA disposed in the right atrium of the heart by utilizing a delivery sheath with a smaller diameter in a percutaneous puncture mode. The LAA occluder can occlude the orifice of the LAA to prevent blood flow in the atrium from entering the LAA, thereby preventing thrombus formation and achieving a purpose of preventing AF-induced thromboembolism. Since 2001, the percutaneous LAAO treatment has been in use, and has successively subject to animal experiments and clinical trials. Based on the clinical trials, the LAAO treatment can effectively reduce the occurrence probability of stroke of the AF patients.

The LAA occluder currently in the market mainly has two types of structures: a plug structure and a double-disc structure.

Because the application time of the LAA occluder is relatively short, the technology is relatively immature, there will be some complications after surgery and affect the living quality of the patient. Among them, residual shunt of an instrument is one of the main complications of LAA occlusion. In the case of the LAA occluder with the plug structure, 8% of patients had residual shunt complications from their 6-month follow-up results, and 32% to 34.5% of patients in different centers had some degrees of residual shunt complications from their 12-month follow-up results. In the case of the LAA occluder with the double-disc structure, 2%˜16.2% of patients in different centers had moderate residual shunt complications from their 12-month follow-up results. The incidence of residual shunt complications is high, which will affect the living quality of patients. Therefore, reducing the residual shunt after LAA occlusion is one of the main goals of improving the clinical application value of the LAA occluder.

The LAA occluder with the double-disc structure usually includes a sealing portion and an anchoring portion. After the LAA occluder is released, the sealing portion occludes the orifice of the LAA, and the anchoring portion is released inside the LAA and is provided with barbs to fix the sealing portion. After being released, the sealing portion of the LAA occluder should be closely attached to the orifice of the LAA to occlude the LAA. If the sealing portion fails to be closely attached to the orifice of the LAA and the sealing portion may be suspended in the left atrium, resulting that a sufficient occlusion effect for the orifice of the LAA cannot be achieved, and the risk of thrombosis may be further increased. A major factor that causes the sealing portion to be ineffectively attached to the LAA is related to the connection between the sealing portion and the anchoring portion. That is, the anchoring portion and the sealing portion fail to be tightly connected together, the overall length of the occluder is relatively longer, and the anchoring portion is radially compressed, further increasing the overall length of LAA occluder after being released, and also causing an increase in the axial distance between the sealing portion and the anchoring portion, such that the sealing portion cannot be effectively attached to the LAA after being released, resulting in residual shunts.

SUMMARY

A left atrial appendage occluder is provided, which advances a connection manner between a sealing portion and an anchoring portion, thereby avoiding and inhibiting an axial elongation of the left atrial appendage occluder as a whole, and further ensuring that the sealing portion is attached to and occludes the left atrial appendage.

A left atrial appendage occluder with advanced connection manner includes a sealing portion and an anchoring portion. Each of the sealing portion and the anchoring portion is provided with a connection part formed by a corresponding converging shape of the sealing portion or the anchoring portion respectively. The connection parts of the sealing portion and the anchoring portion extend toward each other to be fixed and misaligned with each other.

In the related art, the connection parts of the sealing portion and the anchoring portion are generally aligned with each other, and an end surface of the connection part of the sealing portion and an end surface of the connection part of the anchoring portion are directly abutted against each other when the connection parts of the sealing portion and the anchoring portion are directly connected. Of course, a transitional connector can also be adopted, but this structure will lead to an excessive overall axial length of the left atrial appendage occluder, which is disadvantageous for sealing.

In the present disclosure, the connection parts of the sealing portion and the anchoring portion are connected in a staggered manner, such that the connection parts of the sealing portion and the anchoring portion can extend toward each other without spatially interference, a distance between the sealing portion and the sealing portion can be greatly reduced, and the sealing effect can be improved.

In an embodiment, both of the sealing portion1100and anchoring portion1200are integrated with or fixed to their connection part respectively.

The sealing portion and the anchoring portion can be processed by weaving or laser cutting, individually. The sealing portion (or the anchoring portion) can be in a regular or irregular wire frame structure. The sealing portion in the wire frame structure may be provided with a framework, as required, at a suitable position in the wire frame structure to increase a strength, and the framework may have a larger cross-sectional area or have at least a greater strength with respect to other portions of the sealing portion. The sealing portion in the network-shaped structure may include regular or irregular cells, and in an implementation, the network-shaped structure includes diamond-shaped cells or substantially diamond-shaped cells. The network-shaped structure is at least radially compressible to facilitate retraction and release. The mesh-shaped structure explicitly appears a warp and weft structure, and longitudinal parts and latitudinal parts of the mesh-shaped structure intersect with each other via nodes in a fixed manner. In an implementation, the longitudinal parts and the latitudinal parts of the mesh-shaped structure intersect with each other in a non-fixed manner, that is, the longitudinal parts and the latitudinal parts can be slidably moved with respect to each other in an intersecting manner, thereby providing a capability of compliance and deformation.

The sealing portion and the anchoring portion may be integrated with their respective connection parts after a cutting or weaving process. Alternatively, the connection parts are independent members and are fixed with sealing portion and the anchoring portion respectively by welding or the like. In an implementation, the sealing portion and the anchoring portion are integrated with their respective connection parts, thereby facilitating processing and ensuring overall strength.

In an embodiment, the connection part of the sealing portion is formed by converging all or part of the shape of the sealing portion, and the connection part of the anchoring portion is formed by converging all or part of the shape of the anchoring portion.

As the sealing portion and the anchoring portion are used to occlude the left atrial appendage, parts of the sealing portion and the anchoring portion have various diameters ranged within a certain size range, while diameters of the connection parts are smaller. Thus the transition in diameter between a main body of the sealing portion and the connection part of the sealing portion, and a transition in diameter between a main body of the anchoring portion and the connection part of anchoring portion, are gradual or abrupt. For example, when converging all of the shape of the sealing portion and all of the shape of the anchoring portion, a portion of the sealing portion with a varied diameter is in a tapered structure and a portion of the anchoring portion with a varied diameter is in a tapered structure. Converging part of the shape of the sealing portion and part of the shape of the anchoring portion can be considered as an abrupt change in diameter, for example, a portion with a larger cross-sectional area abruptly changes into a rod or a strand with a smaller cross-sectional area.

In an embodiment, each of the sealing portion and the anchoring portion has one connection part connected with the other connection part. Alternatively, each of the sealing portion and the anchoring portion has multiple connection parts, and the multiple connection parts of the sealing portion are connected with the multiple connection parts of the anchoring portion in a one-to-one correspondence.

The number and positions of the connection parts are not strictly limited. In a case that each of the sealing portion and the anchoring portion has only one connection part, the connection part is generally arranged in a middle of the sealing portion or the anchoring portion.

In an embodiment, the connection parts of the sealing portion and the anchoring portion are directly connected or connected via a connector.

When the connection parts of the sealing portion and the anchoring portion are directly connected, that is, the connection parts of the sealing portion and the anchoring portion are in contact with each other, and are fixed to each other by welding, hooping, intertwining, and the like. When the connection parts of the sealing portion and the anchoring portion are connected via a connector, that is, the connection parts of the sealing portion and the anchoring portion may be free from contact with each other, but are respectively fixed with the connector, and the connector may be a single component or an assembly of multiple components.

In an embodiment, each of the connection parts of the sealing portion and the anchoring portion extends along a straight line.

Alternatively, one of the connection parts of the sealing portion and the anchoring portion extends along a straight line and the other of the connection parts of the sealing portion and the anchoring portion extends along a curve line.

Alternatively, each of the connection parts of the sealing portion and the anchoring portion extends along a curve line.

The sealing portion and the anchoring portion are arranged oppositely, and the connection parts of the sealing portion and the anchoring portion extend toward and are connected with each other, and the paths along which the connection parts of the sealing portion and the anchoring portion extend are not strictly restricted during an extending process. In order to simplify the structure, in an implementation, each of the connection parts of the sealing portion and the anchoring portion extends along a straight line.

The connection part itself may be either a simple straight rod or a relatively complicated three-dimensional structure, and thus extending along a straight line herein should be understood as an overall trend, that is, the extending process does not involve with a circuitous or bending shape as a whole.

Further, in an embodiment, the connection parts of the sealing portion and the anchoring portion both extend along an axial of the left atrial appendage occluder.

In an embodiment, the connection parts of the sealing portion and the anchoring portion are nested within or offset with each other at a position in which the connection parts of the sealing portion and the anchoring portion cooperate with each other.

Since the connection parts of the sealing portion and the anchoring portion are arranged in a staggered manner, the connection parts of the sealing portion and the anchoring portion can extend to be staggered with each other in a mutually nested manner or in a mutually offset manner without spatial interference. A mutually offset manner is defined with respect to the mutually nested manner, and should not be understood as being far away from each other. For example, in a cross section perpendicular to the axial of the left atrial appendage occluder, the connection parts of the sealing portion and the anchoring portion may be attached to each other or have a certain gap therebetween.

In an embodiment, the connection parts of the sealing portion and the anchoring portion extend toward each other, and each of the connection parts of the sealing portion and the anchoring portion extends beyond a terminal end of the other connection part.

When one connection part extends beyond the terminal end of the other connection part, it also means that the terminal end of the other connection part extends beyond a terminal end of the one connection part. In this way, the connection parts of the sealing portion and the anchoring portion have projections, in a direction perpendicular to the axial of the left atrial appendage occluder, arranged side by side or at least partially overlap with each other at a position in which the connection parts of the sealing portion and the anchoring portion cooperate with each other.

When one of the connection parts of the sealing portion and the anchoring portion is nested within the other, the projections of the connection parts of the sealing portion and the anchoring portion must overlap. When the connection parts of the sealing portion and the anchoring portion are offset with each other, the shapes of the projections of the connection parts of the sealing portion and the anchoring portion are related to a projection direction, and it is possible that the projections of the connection parts of the sealing portion and the anchoring portion are arranged side by side or partially overlap with each other. When the sealing portion and the anchoring portion are offset with each other and one of the sealing portion and the anchoring portion does not extend beyond a terminal end of the other, the sealing portion and the anchoring portion can be further moved toward each other and the structure of the left atrial appendage occluder is not compact enough.

In an embodiment, the sealing portion and the anchoring portion are in contact with each other at peripheral regions around the connection parts of the sealing portion and the anchoring portion respectively.

The mutual abutment can block a gap between the sealing portion and the anchoring portion, thereby improving the sealing effect.

In an embodiment, the sealing portion and the anchoring portion are abutted against each other at peripheral regions around the connection parts of the sealing portion and the anchoring portion respectively.

The mutual abutment between the sealing portion and the anchoring portion can be achieved by applying a pre-tightening force. After being released, the left atrial appendage occluder can be better attached to and occlude the left atrial appendage, and even if one of the anchoring portion and the sealing portion is radially compressed to lengthen, the sealing portion can be kept to be tightly abutted against the anchoring portion to ensure the sealing effect.

In combination with the related art, one or more layers of flow blocking membrane are disposed inside the sealing portion. A periphery of the anchoring portion can also be coated with a flow blocking membrane, for example, all or part of an outer surface of the anchoring portion is coated with the flow blocking membrane.

Unless otherwise stated, shapes and positional relationships herein are described based on a state in which the left atrial appendage occluder is released and expanded in a body, and the state may also be referred to be a released state or an expanded state. Before being released, the left atrial appendage occluder is compressed within a delivery device to be in a state which may be referred to be a compressed state or a pre-release state.

In an embodiment, the sealing portion and the anchoring portion separately and independently have a wire frame structure or a mesh-shaped structure.

In an embodiment, the sealing portion is a sealing disc or a sealing plug.

It is noted that the term “disc” or “plug” is used to represent a general shape. For example, the term “disc” represents a structure in a flat shape with an outer edge, and the outer edge is in a shape, such as a circular shape or other shapes according to actual requirements, substantially fitted with features of anatomical structures of the left atrial appendage.

For example, the term “plug” is used to represent a structure in a column shape with a certain thickness, such as an approximate cylinder and cone. However, a shape of an outer circumference or a generatrix of the sealing portion is not strictly limited, and can be defined referring to the related art on one hand and the actual requirements on the other hand. The shape of the sealing portion itself is not critical to the present disclosure. But of course, the present disclosure provides a preferred or improved solution for the sealing portion.

In an embodiment, the sealing portion is a sealing disc. The sealing portion is provided with a presetting state and an abutting state. In the presetting state, the sealing portion is free from contact with the anchoring portion. In the abutting state, the sealing portion is in contact with the anchoring portion. A disc bottom of the sealing portion facing the anchoring portion in the abutting state is provided with a deformation axially toward the anchoring portion with respect to the presetting state.

In an embodiment, the sealing portion includes a disc surface facing away from the anchoring portion, the disc bottom facing the anchoring portion, and an intermediate part connecting the disc surface and the disc bottom. The disc bottom is planar, or a middle part of the disc bottom protrudes toward the anchoring portion, or a middle part of the disc bottom protrudes away from the anchoring portion.

The disc surface, the disc bottom, and the intermediate part integrally form a cage-shaped structure. One or more flow blocking membranes may be disposed inside the cage-shaped structure. Parts of the cage-shaped structure other than necessary hollow parts may be closed or partially open. When weaving and processing the sealing portion, one converging end may be formed at each of the disc bottom and the disc surface.

Since the cage-shaped structure has a certain space inside, the sealing effect can be ensured even if there is a certain deformation in the cage-shaped structure. According to the present disclosure, the cage-shaped structure is particularly suitable for achieving a tight abutment against the anchoring portion.

A diameter of the cage-shaped structure mainly includes a diameter of the intermediate part, a diameter of the anchoring portion, and a diameter of the disc surface. The diameter of the intermediate part is substantially equal to the diameter of the anchoring portion. The diameter of the disc surface is slightly larger than the diameter of the intermediate part, so as to improve the sealing effect of an end of the sealing portion.

In an embodiment, the sealing portion is provided with a presetting state and an abutting state. In the presetting state, the sealing portion is free from contact with the anchoring portion. In the abutting state, the sealing portion is in contact with the anchoring portion. A diameter of the disc bottom in the presetting state is larger than a diameter of the disc bottom in the abutting state.

The disc surface or the disc bottom described herein may be in an approximately circular shape. If the disc surface or the disc bottom is in other shapes, it may be appreciated that a cross-sectional area or an overall thickness of the disc bottom in the presetting state is larger than that of the disc bottom in the abutting state. Taking the disc surface and the disc bottom in a circular shape as an example, since a diameter of the disc surface is larger than a diameter of the disc bottom, the sealing portion is in a truncated cone shape as a whole. The sealing portion is progressively converged as it goes toward a bottom end thereof, such that a top surface of an upper end of the sealing portion is slightly larger, and a bottom surface of the bottom end of the sealing portion is slightly smaller. In this way, when the sealing portion is in contact with the anchoring portion, the sealing portion can be conformed to be attached with the anchoring portion.

In an implementation, the sealing portion is provided with a presetting state and an abutting state. In the presetting state, the sealing portion is free from contact with the anchoring portion. In the abutting state, the sealing portion is in contact with the anchoring portion. At least one of the intermediate part and the disc bottom of the sealing portion in the abutting state has a deformation with respect to the presetting state.

The presetting state refers to a state in which a shape of the sealing portion after being processed but before assembling the left atrial appendage occluder or subjecting the sealing portion to an external force. After assembly, since the sealing portion is in abutment against the anchoring portion, and in order to increase or maintain the pre-tightening force between the sealing portion and the anchoring portion, the sealing portion is deformed after being abutted against the anchoring portion.

In an embodiment, the intermediate part of the sealing portion in the abutting state has a radially contracted deformation with respect to the presetting state.

When the sealing portion and the anchoring portion are moved away from each other or subjected to a radially compression, the radially contracted deformation can offset or delay a tendency of an axial elongation of the left atrial appendage occluder to ensure a sealing for an opening portion of the left atrial appendage. The radially contracted deformation allows the intermediate part to have a certain taper and to better fit the left atrial appendage, so as to improve the sealing effect.

In an embodiment, the disc bottom of the sealing portion in the abutting state is provided with a deformation protruding axially toward the anchoring portion with respect to the presetting state.

Based on a similar principle, the deformation protruding axially toward the anchoring portion can also offset or delay the axial elongation as a whole. The abutment between the sealing portion and the anchoring portion is substantially maintained to ensure the sealing effect.

In an embodiment, the sealing portion abuts against the anchoring portion at least at an outer edge of the disc bottom. The outer edge of the disc bottom is abutted against the anchoring portion, and a greater deformation of the sealing portion can be obtained under a same pre-tightening force, which is more favorable for compensating and offsetting the axial elongation.

In an embodiment, connection parts of the sealing portion and the anchoring portion are connected in a staggered manner.

In an embodiment, the sealing portion and the anchoring portion are constricted and converged respectively, and the sealing portion and the anchoring portion are connected together via a connector.

In the case that the sealing portion and the anchoring portion each have mesh-shaped structures, wires for weaving the sealing portion and the anchoring portion are bundled individually and further connected with each other via a connector. Structure features is formed by bundling the wires, corresponding steps in the processing are included in the process of bundling, and that is, multiple wires are converged and bundled into one strand.

In the case that the sealing portion and the anchoring portion each have wire frame structures, the sealing portion or the anchoring portion is generally formed by cutting a pipe, and an end terminal of the pipe can be considered as a converging part.

In an embodiment, the sealing portion includes a bottom part facing the anchoring portion, and the bottom part of the sealing portion includes a first converging part. A middle part of the anchoring portion in a radial direction includes a second converging part. The connector is provided with two passages, and the first converging part and the second converging part extend through and are fixed to the two passages correspondingly.

Pulling the first converging and the second converging toward the connector in opposite directions may cause the main bodies of the sealing portion and the anchoring portion to be moved close to and until tightly abutted against each other. The first converging and the second converging are pulled through separate channels, thereby avoiding interference and facilitating assembly.

In an embodiment, the two passages of the connector are arranged side-by-side or are arranged in a nesting inside and outside manner. In general, two channels are arranged offset from each other, thereby further avoiding interference during pulling the first converging part and the second converging part and facilitating assembly.

In an embodiment, the anchoring portion extends from the connector away from the sealing portion to form an extending portion. One side of the extending portion facing away from the connector is bent outward and turns back to the bottom part of the sealing portion to form a turning-back portion. The turning-back portion is abutted against the bottom part of the sealing portion.

The anchoring portion is an outward bent structure as a whole. The turning-back portion extends around a periphery of the extending portion, such that the turning-back portion and the extending portion together form a double-layer structure. A certain space is defined inside the double-layer structure, which can accommodate and allow a deformation of the anchoring portion, after the anchoring portion is tightly abutted against the sealing portion, without weakening the anchoring effect.

In an embodiment, the anchoring portion extends from the connector away from the sealing portion to form an extending portion. One side of the extending portion facing away from the connector is bent outward and turns back to the bottom part of the sealing portion to form a turning-back portion. The turning-back portion bends inward and is constricted at the bottom part of the sealing portion to form a necked opening portion. The necked opening portion abuts against the bottom part of the sealing portion.

The necked opening portion extends inward substantially and radially to be in surface contact with the bottom part of the sealing portion, thereby facilitating applying a pre-tightening force. Although the anchoring portion and the sealing portion are in hollow structures, the surface contact herein can be understood as an abutment between mesh-shaped surfaces, and it is not necessary to be limited to a surface contact between solid bodies.

In an embodiment, the first converging part is disposed at a center of the bottom part of the sealing portion. The necked opening portion extends upward to abut against an outer edge of the bottom part of the sealing portion. In this way, the bottom part of the sealing portion is formed into an inverted cone shape under the action of the pre-tightening force.

In an embodiment, the necked opening portion is suspended above a periphery of the extending portion or connected to the extending portion.

When the necked opening portion is suspended above the periphery of the extending portion, that is, the necked opening portion and the periphery of the extending portion are not connected or only slightly contact with each other, and are freely movable relative to each other when deformed. When the necked opening portion is connected to the extending portion with one of a fixed connection, a sliding connection, and a rotation fit, a relative movement between the necked opening portion and extending portion is restrained in some extent.

In an embodiment, the extending portion is in a tapered shape, and an end of the extending portion having a larger diameter is disposed away from the connector and is provided with an opening.

The extending portion is in a horn-shaped structure, thereby facilitating retraction and improving strength and structural stability at a flared end (that is, the end of the extending portion provided with the opening).

In an embodiment, the anchoring portion is provided with a presetting state and an abutting state. In the presetting state, the anchoring portion is free from contact with the sealing portion. In the abutting state, the anchoring portion is in contact with the sealing portion. The connector is farther away from the sealing portion than the necked opening portion along an axial direction of the anchoring portion in the presetting state.

That is, when the sealing portion is moved toward the anchoring portion, the necked opening portion comes in contact with the bottom part of the sealing portion first, and meanwhile, the connector is still at a distance from the sealing portion, and this distance also allows a further pulling to form the pre-tightening force.

In an embodiment, the connector is flush with the necked opening portion or farther away from the sealing portion than the necked opening portion along the axial direction of the anchoring portion in the abutting state.

In an embodiment, the connector includes an outer ring and an inner ring nested within the outer ring. The bottom part of the sealing portion includes the first converging part and the middle part of the anchoring portion in the radial direction includes the second converging part. One of the first converging part and the second converging part extends through and is fixed in the inner ring, and the other one of the first converging part and the second converging part extends through and is fixed in a gap between the inner ring and the outer ring.

In an embodiment, the connector includes an outer ring and an inner ring nested within the outer ring. The bottom part of the sealing portion includes a first converging part and the middle part of the anchoring portion in the radial direction includes a second converging part. One of the first converging part and the second converging part extends through and is fixed in a gap between the inner ring and the outer ring, and the other one of the first converging part and the second converging part penetrates through the inner ring and is provided with a retainer abutted against the connector. The retainer is fixed to one end of the inner ring where the other one of the first converging part and the second converging part extends out.

In an embodiment, the connector includes a body having two passages arranged side by side. The bottom part of the sealing portion includes the first converging part and the middle part of the anchoring portion in the radial direction includes the second converging part. The first converging part and the second converging part extend through the two passages respectively and are provided with two retainers abutted against respective sides of the passages where which the first converging part and the second converging part extend out correspondingly.

The connector and the retainer may be stainless steel, nickel titanium alloy, or other metal material that meets biocompatibility requirements.

In an embodiment, the anchoring portion has an abutting portion that abuts against the sealing portion. In a compressed state, the anchoring portion is in a cylindrical structure, and the abutting portion is on an inner wall of the cylindrical structure.

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

When the left atrial appendage occluder is released, the anchoring portion bends outward, such that the abutting portion originally located on the inner wall of the cylindrical structure bends to be outside and faces the sealing portion, and the abutting portion is further tightly abutted against the sealing portion.

In the compressed state, if the abutting portion is on the outer wall of the cylindrical structure, the anchoring portion needs to bend in a more complicated manner, otherwise it is difficult for the anchoring portion to achieve a larger outer diameter to support and anchor at an inner wall of the left atrial appendage.

However, when the anchoring portion is to be bent in a complicated manner, the tendency of extending outward of an end terminal of the anchoring portion (i.e., a distal end of the anchoring portion in the compressed state) can be changed, and the inner wall of the left atrial appendage can be prevented from being stabbed, thereby improving the safety.

In an embodiment, the anchoring portion and the sealing portion are directly connected and abutted against each other in a using state.

In a normal using state, the anchoring portion may be in direct contact with and abutted against the sealing portion. However, during using, the anchoring portion and the sealing portion are not always in the state of directly contacting with and abutting against each other. Under the action of a special anatomical structure or after being used for a period of time, the anchoring portion and the sealing portion may also be moved away from each other and even bring a gap created between the anchoring portion and the sealing portion.

In an embodiment, the sealing portion is a two-layer structure. The two-layer structure includes a bottom layer facing the anchoring portion and a top layer facing away from the anchoring portion. The sealing portion is connected to the anchoring portion through the bottom layer.

Alternatively, a part of the anchoring portion extends through the sealing portion to connect with the top layer of the sealing portion. In the present disclosure, the anchoring portion is connected to the bottom part of the sealing portion, it is favorable for obtaining a pre-deformation or a higher deformation efficiency of the sealing portion when the anchoring portion and the sealing portion are mutually abutted.

In an embodiment, one or more layers of flow blocking membrane are provided inside the two-layer structure.

Since a sealing portion with a two-layer structure is more likely to be loose and elongated axially, the present disclosure is also preferably applicable to a sealing portion with a two-layer structure. Both a sealing portion in a disc shape and in a column shape can be regarded as a two-layer structure with a flow blocking membrane provided inside.

In an embodiment, the sealing portion and the anchoring portion are formed individually and abut against each other during an assembling process.

The sealing portion and the anchoring portion are formed separately and thermoformed individually and then are assembled together. During assembly, a pre-deformation effect can be obtained by causing the sealing portion and the anchoring portion abutted against each other tightly. If the sealing portion and the anchoring portion are formed in an integrated structure, an abutting effect can also be obtained. However, since the sealing portion and the anchoring portion are formed integrally rather than assembled together, it is necessary to obtain the abutting effect after thermoforming, resulting in higher requirements for a thermoforming technic, and it is required that the sealing portion and the anchoring portion are separately thermoformed, thereby increasing the processing difficulty.

In order to obtain a better effect of support and anchoring, the anchoring portions are deployed continuously circumferentially.

Although a mesh-like or a rod-like structure has some gaps along the axial direction, it should be continuously extended in the axial direction in terms of the overall structure and distribution, in order to obtain a more uniform force distribution and stable support, and to avoid providing support merely by circumferentially local structure.

In an embodiment, a part of the anchoring portion abutted against the sealing portion is adjacent to an outer edge of the anchoring portion.

In an embodiment, a part of the sealing portion abutted against the anchoring portion is adjacent to an outer edge of the sealing portion.

The outer edges of the sealing portion and the anchoring portion abutting against each other facilitates an axial deformation or a radially convergence, and increasing deformation quantity under a same force.

In an embodiment, after thermoforming, the sealing portion and the anchoring portion are assembled together, and the sealing portion and the anchoring portion are in a first state in an initial contact with each other during assembly, and the connection parts of the sealing portion and the anchoring portion are in a second state after axially moving a predetermined distance toward each other.

In the first state, the sealing portion and the anchoring portion have been and are just in contact with each other. Since both the sealing portion and the anchoring portion have been thermoformed, and when they are further axially moved toward each other, one of them will deform and maintain a stress caused by the deformation in the second state.

In an embodiment, the connection parts of the sealing portion and the anchoring portion are respectively disposed at middle parts of the sealing portion and the anchoring portion in a radial direction. In the first state, the sealing portion and the anchoring portion are in contact with each other at peripheral regions around the connection parts of the sealing portion and the anchoring portion respectively.

The pre-tightening force is also derived from the above-mentioned stress. If the thermoforming is performed after assembly rather than before assembly, the stress will disappear during the thermoforming and the pre-tightening force required cannot be created.

Therefore, it is noted that, in the second state, a relative positional relationship between the sealing portion and the anchoring portion is obtained after assembly, and the thermoforming is not performed after the second state.

Since the anchoring portion has greater stiffness, and generally, the stress is mainly generated from the deformation of the sealing portion.

In an embodiment, in the second state a part of the sealing portion connected with the anchoring portion moved towards the anchoring portion with respect to the first state.

In the second state, a distance in which the connection parts of the sealing portion and the anchoring portion axially move toward each other affects a magnitude of the stress, and therefore, it is necessary to define and control the distance in an adaptive manner during assembly.

In an embodiment, the predetermined distance is defined according to one of: an axial force of the connection parts between the sealing portion and the anchoring portion, a pressing force at contacting parts of the sealing portion and the anchoring portion, and a deformation of the part of the sealing portion connected with the anchoring portion.

In an embodiment, the deformation is an axial displacement of a predetermined part of the sealing portion, or an angle between the predetermined part of the sealing portion and an axis of the sealing portion.

The predetermined part of the sealing portion is a part that is deformed from the first state to the second state. For ease of expression and measurement, a part with a larger deformation can be selected as the predetermined part. For example, the predetermined part of the sealing portion is a part of the sealing portion in contact with the anchoring portion in the first state.

During assembly, the magnitude of the stress can be obtained by detecting variations of the predetermined distance.

If it fails to provide such stress, even if there is a local contact between the sealing portion and the anchoring portion during assembly, when the left atrial appendage occluder is axially elongated as a whole during use (that is, the sealing portion and the anchoring portion are away from each other), an inherent recovery force between the sealing portion and the anchoring portion is smaller, an overall axial elongation of the left atrial appendage occluder is counteracted merely by the elasticity of the respective materials.

The left atrial appendage occluder according to the present disclosure is first thermoformed and then is assembled by retaining an axial stress, the overall axial elongation of the left atrial appendage occluder in a subsequent use process can be better counteracted. The recovery force is increased by superposing the pre-tightening force and resilient forces of the sealing portion and the anchoring portion, thereby ensuring the sealing effect for long-term use.

A method for manufacturing a left atrial appendage occluder with advanced connection manner is also provided. The method is carried out as following. Thermoforming is performed on a sealing portion and an anchoring portion. When assembling the sealing portion with the anchoring portion, the sealing portion and the anchoring portion is moved toward each other to reach a first state, and in the first state the sealing portion and the anchoring portion are in initial contact with each other. The sealing portion and the anchoring portion is further moved axially toward each other a predetermined distance to reach a second state. And then, connection parts of the sealing portion and the anchoring portion are fixed together, the connection parts of the sealing portion and the anchoring portion are maintained in the second state to complete assembly.

Since the sealing portion and the anchoring portion have been in partial contact with each other in the first state, and therefore, when the left atrial appendage occluder is transformed into the second state from the first state, an axial distance between the overall sealing portion and the anchoring portion is not changed, only a stress generated from local deformations is changed.

The left atrial appendage occluder according to the present disclosure is delivered to the left atrial appendage of the heart by utilizing a delivery sheath in a percutaneous puncture mode, so as to block the left atrial appendage and to avoiding a risk of a stroke in patients with atrial fibrillation due to thrombus formation in the left atrial appendage.

A staggered connection between the sealing portion and the anchoring portion is realized by the advanced connection manner according to the present disclosure, thereby enabling the sealing portion to be tightly attached to the left atrial appendage to occlude an orifice of the left atrial appendage and reducing the incidence of endoleaks and residual shunts.

