Patent Description:
At present, therapy for treating diseases by interventional catheterization technique is widely applied, and a variety of materials, apparatuses and drugs are placed into the heart, arteries and veins of the human body through this treatment. When an occluder is placed into the heart, arteries, veins, and left atrial appendage by the catheter interventional method, due to complex anatomical structures of the heart, the artery and vein blood vessels, especially the left atrial appendage, the apparatus is required tobe delivered to a predetermined position accurately, and to be well-adapted to the anatomical structure, mechanics requirements and hemodynamics requirements of the predetermined position at the same time. Under the premise of only generating microtrauma to the human body, firstly, the skin near the blood vessel is punctured, a guide wire enters into the blood vessel from the puncturing site, one end of a catheter is delivered to the predetermined position under the guidance of the guide wire, and the other end thereof is reserved in vitro, and then the apparatus is transferred to the predetermined position by using the catheter and a pusher. During such procedure, a fine flexible catheter is required, while the catheter and the guide wire are designed tobe visualized under the X ray. Once the catheter reaches the predetermined position, the guide wire is removed, and the apparatus is guided to the tail end of the catheter by using an access established by the catheter through the pusher; when being completely exposed from the tail end of the catheter, the apparatus is released from the pusher. For example, the occluder is placed into the left atrial appendage by using the catheter interventional method, in order to prevent thrombosis from the left atrial appendage causing atrial fibrillation, and strake caused by ascending the thrombus to the brain; or in order to prevent systemic embolism caused by the thrombus reaching to other parts of the body through a body blood circulation system. Placing the occluder into the left atrial appendage to occlude the left atrial appendage and block the blood flow entering into the left atrial appendage can eliminate the risk of thrombosis formed in the left atrial appendage, thus preventing strake. At present, the apparatuses are usually threadedly connected to a delivery sheath.

<CIT> discloses left atrial appendage occluder comprising sealing disc connected to a fixing bracket, where the fixing bracket comprises a connecting portion and a plurality of supports. The supports form supporting segments, each segment being provided with least one anchoring barb.

<CIT> relates to an implantable medical device for insertion in the left atrial appendage including a cap coupled to a frame. The cap constrains movement of the legs of the frame during collapse or expansion of the device such that the device can be deployed, recalled and redeployed without the device being damaged or the legs of the frame getting tangled.

<CIT> relates to an apparatus for permanent placement across an ostium of a left atrial appendage in a patient, which includes a filtering membrane configured to extend across the ostium of the left atrial appendage. The filtering membrane has a permeable structure which allows blood to flow through but substantially inhibits thrombus from passing therethrough.

<CIT> relates to devices, methods and systems for occluding an opening within the tissue of a body, such as a left atrial appendage. In one example, a medical device includes an occluder portion and an anchor portion, the anchor portion being hingably connected to the occluder portion. With this arrangement, the anchor portion actuates and pivots relative to the occluder portion between an anchor deployed position and an anchor non-deployed position.

<CIT> relates to atrial appendage occlusion devices and arrhythmia treatment.

<CIT> relates to a method of manufacturing a medical implant or structures for a medical implant. Disclosed is an improved occluder, which does not damage the surrounding body tissue. In one example, a method for manufacturing a 3D fabric of strands for forming an occluder is provided.

<CIT> relates to an instrumentation for percutaneous delivery of blood filtration devices to atrial appendages including a curved access sheath and a delivery tube. A compressed filter device attached to a tether wire is loaded in the delivery tube. The loaded delivery tube is advanced through the pre-positioned access sheath to place the device in a deployment position.

With reference to <FIG> shows another known left atrial appendage occluder located in an anatomical structure of the heart and the left atrial appendage, and <FIG> is a structure diagram of the existing left atrial appendage occluder, wherein <NUM> means left atrium, <NUM> means left atrial appendage and <NUM> means left atrial appendage cavity wall. The occluder includes a sealing disc <NUM> and a fixing bracket <NUM> which consists of a plurality of supports <NUM>; a fixing anchor (or referred to as anchoring barb) <NUM> is arranged on each of the supports <NUM>, and the supports <NUM> are extended to ball ends of support ends <NUM> starting from a position where the fixing anchor <NUM> is located, and spaced from each other; a connecting nut <NUM> is arranged on the sealing disc <NUM> of the left atrial appendage occluder.

The occluder has good elasticity, may be contained in a sheath with width of <NUM> to <NUM>, transferred into the left atrial appendage <NUM> through the vascular access, and slowly retreated from the sheath tube; the fixing bracket <NUM> of the occluder will be unfolded in the left atrial appendage cavity, and the supports <NUM> of the fixing bracket <NUM> will be pressed on the left atrial wall by adapting to the shape of the left atrial appendage <NUM>, while the fixing anchor <NUM> of the supports <NUM> will be penetrated into the inner wall <NUM> of the left atrial appendage, thus guaranteeing reliable fixation, and, the sealing disc <NUM> is covered on the ostium of the left atrial appendage <NUM>, as shown in <FIG>.

Finally, a steel cable connected to the left atrial appendage occluder is released, thus occluding the left atrial appendage and blocking the blood flow entering into the left atrial appendage.

The known left atrial appendage occluders have the following limitations: the support ends of the fixing bracket are spaced and suspended. When the fixing bracket is pushed out after being placed into the sheath tube, the risk of twisting between the support ends exists, resulting in possible failure of the fixing bracket to unfold properly, and therefore a failed procedure.

An object of the present invention is to provide a left atrial appendage occluder, that avoids twisting between the supports.

According to the present invention, a left atrial appendage occluder is provided as defined in claim <NUM>. The occluder includes a sealing disc and a fixing bracket which is connected to the sealing disc and located at one side of the sealing disc; the fixing bracket including a connecting portion connected to the sealing disc, and a plurality of supports; extending out distally from the connecting portion and defining a recessed area, the plurality of supports are bent to extend proximally to form a plurality of spaced suspended supporting segments, the supporting segment being provided with at least one anchoring barb facing the sealing disc. The left atrial appendage occluder further includes a thin film, all the supports being connected one after another through the thin film. At least one anchoring barb penetrates through the thin film. The supports are further provided with a plurality of fixing holes, through which the thin film is fixed on the supports by suturing.

In an embodiment of the present invention, the thin film includes at least one annular thin film which is fixed on all the supports and encircles the recessed area to expose the whole or apart of the recessed area.

In another embodiment of the present invention, the thin film includes a spherical thin film further covering the recessed area.

In another embodiment of the present invention, the thickness of a portion of the thin film located in an area surrounding the anchoring barb is larger than or equal to that of the rest portion of the thin film.

In another embodiment of the present invention, a proximal edge of the thin film is <NUM> to <NUM> away from a root of the anchoring barb.

In another embodiment of the present invention, after penetrating through the thin film, the length of the anchoring barb extending outside is between <NUM> and <NUM>. In another embodiment of the present invention, the thin film is made of PET or PTFE or silica gel.

In an embodiment of the present invention, the thin film includes a plurality of overlapped thin film layers.

In an embodiment of the present invention, the thin film includes multiple sheets of thin film distributed at interval on the fixing bracket along the direction from the distal end to the proximal end.

In the left atrial appendage occluder according to an embodiment of the present invention, the supports include a plurality of guiding segments, a plurality of branching segments and a plurality of suspended supporting segments successively radiating out distally from the connecting portion. In another embodiment of the present invention, the plurality of guiding segments are coordinated with each other to define a recessed area by regarding the connecting portion as a center; one end of each guiding segment away from the connecting portion is respectively connected to two branching segments; the two branching segments form an included angle; each branching segment is intersected with one of the two branching segments corresponding to the adjacent guiding segment which is adjacent thereto, and bent to extend proximally to form the suspended supporting segments.

Compared with the prior art, the technical solution employed by the present invention at least has the following advantages: the left atrial appendage occluder further includes the thin film through which all the supports are connected behind one another, the present invention effectively restrains the relative position and relative movement between the supporting segments through the thin film, thus avoiding twisting of the supporting segments when the fixing bracket is pushed out and released from a delivery sheath.

The present invention will be further illustrated as below with reference to accompanying drawings which show embodiments, in the drawings:.

In order to understand the object, the technical solution and the advantages of the present invention more clearly, the present invention will be further described in detail with reference to the accompanying drawings and embodiments.

With reference to <FIG>, an embodiment of the present invention provides a left atrial appendage occluder <NUM> that includes a sealing disc <NUM>, a fixing bracket <NUM> connected to the sealing disc <NUM> and located at one side of the sealing disc <NUM>, and a thin film <NUM> fixed on the fixing bracket <NUM>.

The sealing disc <NUM> is formed by braiding a nickel titanium wire or a biocompatible polymer wire, and located at the proximal end relative to the fixing bracket <NUM>.

The fixing bracket <NUM> includes a connecting portion <NUM> connected to the sealing disc <NUM>, and a plurality of supports <NUM>. After radiating out distally from the connecting portion <NUM> and coordinating to form a recessed area <NUM>, the plurality of supports <NUM> are bent to extend proximally to forma plurality of spaced suspended supporting segments <NUM>, the supporting segments <NUM> are provided with at least one anchoring barb <NUM> facing the sealing disc <NUM>. In actual manufacturing, the plurality of supports <NUM> may be formed by cutting a nickel titanium tube from one end thereof along the direction towards the other end, expanded by using a mould, and shaped by heat treatment; the portion of the nickel-titanium tube which is not cut off forms the connecting portion <NUM>. The number of the supports <NUM> may be determined according to the requirements of the mechanical properties and size specifications, such as six, eight, nine, twelve, and sixteen, etc. During the cutting, the anchoring barb <NUM> arranged on the supports <NUM> is cut off at the same time.

With reference to <FIG>, the supports <NUM> include a plurality of guiding segments <NUM>, a plurality of branching segments <NUM> and a plurality of suspended supporting segments <NUM> successively radiating out distally from the connecting portion <NUM>. The plurality of guiding segments <NUM> are coordinated with each other to forma recessed area <NUM> by regarding the connecting portion <NUM> as a center. One end of each guiding segment <NUM> away from the connecting portion <NUM> is respectively connected to two branching segments <NUM>. The two branching segments <NUM> form an included angle, preferably, an acute angle. Each branching segment <NUM> is intersected with one of the two branching segments corresponding to the adjacent guiding segment <NUM> which is adjacent thereto, and bent to extend proximally to form the suspended supporting segments <NUM>. The supporting segments <NUM> are spaced from each other. In other words, each guiding segment <NUM>, encircling the connecting portion <NUM>, terminates into the two branching segments <NUM> connected thereto, to forma similar V-shaped or herringbone shape; and two adjacent V-shaped or herringbone structures, after being connected to one end away from the connecting portion <NUM>, are extended to forma supporting segment <NUM>. The supporting segment <NUM> is approximately U-shaped, one end thereof connected to the branching segments <NUM> is provided with an anchoring barb <NUM>, and the suspended end thereof is processed to forma sphere <NUM>. With reference to <FIG>, the ends of the guiding segments <NUM> and the branching segments <NUM> near the supporting segment <NUM> are all provided with a plurality of fixing holes <NUM>.

Still as shown in <FIG>, the thin film <NUM> is usually made of PET or PTFE or silica gel material, and may also be made of other thin film with biocompatibility and physical performance meeting the requirements. The thin film <NUM> includes an annular thin film fixed on all the branching segments <NUM> of the fixing bracket <NUM> in a manner of coordination of the anchoring barb <NUM> and suturing, thus being connected in series to all the supports <NUM> to expose the whole or apart of the recessed area <NUM>. After the occluder <NUM> is released in the left atrial appendage, the thin film <NUM> constitutes the outer surfaces of the supports <NUM> in contact with the inner wall of the left atrial appendage. The suturing means that the suture passes through the fixing holes <NUM> and then passes through the annular thin film <NUM>, and then is knotted to fix the thin film <NUM>. As shown in <FIG>, the width of the thin film <NUM> may be determined by a position from the anchoring barb <NUM> to the fixing holes <NUM> of the supports <NUM> of the fixing bracket <NUM> and the annular thin film <NUM>. In the present embodiment, the thin film <NUM> may proximally extend <NUM> to <NUM> from the root of the anchoring barb <NUM>, and the thin film <NUM> may distally extend <NUM> to <NUM> from the fixing holes <NUM> of the supports <NUM> and the annular thin film <NUM>. The thickness of the thin film <NUM> shall meet the following conditions: after penetrating through the thin film <NUM>, the length of the anchoring barb <NUM> extending out the thin film <NUM> is equal to or more than <NUM> and less than or equal to <NUM>, in order to ensure that the anchoring barb <NUM> will not fall off after being inserted into the left atrial appendage.

<FIG> shows a schematic diagram of the left atrial appendage occluder released in the left atrial appendage, as shown in <FIG>, when the fixing bracket <NUM> is placed into the left atrial appendage, the fixing bracket <NUM> and the annular thin film <NUM> are unfolded in the state shown in <FIG>, the supports <NUM> of the fixing bracket <NUM> and the annular thin film <NUM> are laminated together in the inner wall <NUM> of the left atrial appendage, the contact surface between the fixing bracket <NUM> and inner wall <NUM> is a cylindrical surface. This is compared with the known left atrial appendage occluder as shown in <FIG> in which only each support <NUM> and the inner wall <NUM> are in contact, the contact area being enlarged dozens of times. In this way, the stress is more evenly distributed along the inner wall <NUM>, so that the penetrating length of the anchoring barbs <NUM> on the supports <NUM> are approximately same into the inner wall <NUM>. At the same time, the stress per unit area is smaller, thus avoiding damage to the inner wall <NUM> caused by excessive stress on a certain site.

Moreover, the thin film <NUM> plays a role of effectively restraining the relative position and relative movement between the supports <NUM>. The thin film <NUM> has soft, thin, compressible and elastic characteristics, so that the thin film <NUM> can be always retained on the supports <NUM> and folded and unfolded along with the supports <NUM> in the process of placing the fixing bracket <NUM> into a delivery sheath and then pushing out from the delivery sheath, thus reducing or even avoiding the risk of twisting of the supports <NUM>, and ensuring smooth operation of the procedure. Further, due to the structure and size characteristics of the annular thin film <NUM>, the edge thereof is at a certain distance from the root of the anchoring barb <NUM>, when the anchoring barb <NUM> is penetrated into the inner wall <NUM> of the left atrial appendage to a certain depth, the annular thin film <NUM> will inhibit the anchoring barb <NUM> from moving deeply into the wall <NUM>, such that the depth of the anchoring barb <NUM> penetrated into the wall <NUM> is controllable and extensive damage to the wall <NUM> caused by uneven stressing is decreased. In addition, in an extreme instance, such as the wall <NUM> is punctured by an anchoring barb <NUM>, in accordance with the existing left atrial appendage occluder, blood will run out from the wall <NUM> and flow inside the left atrial appendage and then be seeped into the pericardial cavity from the pierced position, resulting in pericardial effusion, seriously resulting in cardiac arrest and threatening life. But for the present embodiment, once the wall <NUM> is punctured by the anchoring barb <NUM>, the thin film <NUM> will immediately cover the punctured position while facilitating formation of microthrombus nearby, the throughhole resulted from the puncturing is blocked by the thrombus, such that the blood is prevented from seeping into the pericardial cavity, and the risk of pericardial effusion and even cardiac arrest is reduced. At the same time, the thin film can accelerate thrombosis of the blood in the left atrial appendage and then muscularize, and accelerate the process of muscularization of the left atrial appendage.

With reference to <FIG>, a left atrial appendage occluder <NUM> provided by another embodiment of the present invention has a structure similar to that of the left atrial appendage occluder <NUM>, including a sealing disc <NUM>, a fixing bracket <NUM> connected to the sealing disc <NUM> and located at one side of the sealing disc <NUM>, and a thin film <NUM> fixed on the fixing bracket <NUM>. The difference of the occluder <NUM> from the left atrial appendage occluder <NUM> lies in that, the thin film <NUM> is spherical, a proximal edge thereof is <NUM> to <NUM> away from the root of an anchoring barb <NUM>, and a distal part of the thin film <NUM> covers the whole recessed area (covered, not shown).

The thin film <NUM> and the supports <NUM> are sutured together through the fixing holes <NUM>, <NUM>. Each group of the fixing holes <NUM> and <NUM> is arranged in the same positions on each support <NUM>. The fixing manner is the same as that of the first embodiment.

In addition to the same action mechanism and advantages as the first embodiment, the thin film <NUM> further has the following characteristics as follows: in some extreme instances, such as shown in <FIG>, the entrance of the left atrial appendage is not completely sealed by the sealing disc <NUM> of the left atrial appendage occluder, the blood may enter the left atrial appendage along the direction represented by an arrow <NUM>, at this moment, the thin film <NUM> in the second embodiment will act as a second barrier near the entrance in the left atrial appendage, thus preventing the blood from entering into a deeper portion of the left atrial appendage and reducing the thrombosis risk.

Compared with the above embodiments, the left atrial appendage occluder of the present embodiment is capable of blocking the blood flow entering into a deeper position in the chamber of the left atrial appendage due to the entrance of the left atrial appendage not being completely sealed by the sealing disc <NUM> of the left atrial appendage occluder, thus reducing the thrombosis risk.

The thin film may have different thicknesses according to different areas. For example, the thickness of a portion of the thin film located surrounding the anchoring barb is larger than or equal to that of the other portions of the thin film. Thus, once the wall of the left atrial appendage is punctured by the anchoring barb, the thickened thin film located surrounding the anchoring barb will more effectively prevent hemorrhage after the anchoring barb penetrates into the left atrial appendage, and accelerate thrombosis. In other embodiments, the thin film comprises laminated films, and more thin film layers are located surrounding the anchoring barb. For example, the thin film may include a first thin film layer which is an hemispherical thin film and a second thin film layer which is an annular thin film, the first thin film layer and the second thin film layer are laminated in the area surrounding the anchoring barb, to increase the thickness of the thin film in the area surrounding the anchoring barb. In other embodiments, the thin film includes multiple sheets of thin film distributed at interval on the fixing bracket along the direction from the distal end to the proximal end.

Claim 1:
A left atrial appendage occluder, comprising
a sealing disc (<NUM>) and a fixing bracket (<NUM>) which is connected to the sealing disc (<NUM>) and located at one side of the sealing disc (<NUM>), the fixing bracket (<NUM>) comprising a connecting portion (<NUM>) connected to the sealing disc (<NUM>) and
a plurality of supports (<NUM>) extending out from the connecting portion (<NUM>) in a distal direction and being bent in a proximal direction, to define a recessed area (<NUM>) and to form a plurality of spaced suspended supporting segments (<NUM>), the supporting segments each being provided with at least one anchoring barb (<NUM>) facing the sealing disc (<NUM>),
characterized in that the left atrial appendage occluder further comprises a thin film (<NUM>), at least one anchoring barb (<NUM>) penetrating through the thin film (<NUM>) and all of the supports (<NUM>) being connected one after another through the thin film (<NUM>), and
wherein the supports (<NUM>) are further provided with a plurality of fixing holes (<NUM>), through which the thin film (<NUM>) is fixed on the supports (<NUM>) by suturing.