Covered stent

Abstract

The present application relates to a kind of stent body, film and set on the several barbs of the stent body, the stent body includes the natural state of not being subjected to other external force and the compressed state of loading completion, the film covers the stent body, the barb includes the joint portion in the root of the barb, the film covers the stent body and at least part of the joint portion.The film stent provided by the present application, by setting the joint portion in the root of the barb, the combination effect of film and barb is strengthened, the joint portion is fully contacted with the barb and film, when using traditional heat treatment process to combine, the barb and film can also be reduced or prevented from mutual separation in the rebound process of the barb, to avoid blood entering the inside of film in turn contacting bare stent by gap, affect the service performance and life of overall film stent.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, and in particular to a covered stent. Background Technology

[0002] With the rapid increase in the incidence of hypertension, the incidence of arterial-related diseases is also rising significantly, and is projected to increase by more than 40% in the next 5 to 7 years. Acute Stanford type A aortic dissection (AADA) is the most common and dangerous aortic emergency in cardiovascular surgery. Without treatment, the mortality rate of AADA within one week is as high as 50-91%. With only conservative medical treatment, the 24-hour mortality rate reaches 20%, and the 48-hour mortality rate can reach 30%. Therefore, AADA, once diagnosed, requires emergency surgical intervention if there are no contraindications. However, even under modern medical conditions, the perioperative mortality rate is as high as 15-35%.

[0003] Currently, minimally invasive endovascular interventional surgery can be used to treat the above-mentioned diseases. Specifically, a covered stent is implanted into the blood vessel to isolate the blood flow from the aortic dissection. During use, the stent is typically first compressed and loaded into a sheath in its unstressed, naturally positioned state, facilitating subsequent transport and release to the designated site. During stent loading, the stent transitions from a naturally positioned state to a compressed state. After transporting the stent to the designated location, it is released from the sheath, returning to its naturally positioned state.

[0004] Existing covered stents typically enhance their anchoring ability in blood vessels by incorporating barbs. The manufacturing process generally involves first covering the inner and outer surfaces of the bare stent with a membrane, then using a specialized tool to insert the barbs through the outer surface of the membrane, and finally performing heat treatment to bond the membrane to the bare stent. However, in current technology, the barbs are laser-cut, resulting in a relatively smooth surface. After heat treatment, the adhesion between the membrane covering the barb edges and the barbs is poor. During compression and rebound, the membrane easily detaches from the barbs and cannot move with them, creating gaps between the membrane and the barbs. This allows blood to enter the membrane through these gaps and subsequently contact the bare stent, affecting the overall performance and lifespan of the covered stent. Summary of the Invention

[0005] Based on this, the present invention provides a covered stent to solve the problem that the barbs of the covered stent are prone to detach from the covering at the base of the barbs during the release process.

[0006] A covered stent is provided, including a stent body, a cover, and a plurality of barbs disposed on the stent body. The stent body includes a natural state without being subjected to other external forces and a compressed state after loading. The cover covers the stent body, and the barbs include a joint located at the root of the barb. The cover covers the stent body and at least a portion of the joint.

[0007] In one embodiment, the bonding portion includes a filament that wraps around the base of the barb and is located between the coating and the barb.

[0008] In one embodiment, the joint includes a plurality of grooves, which are staggered and distributed on the side of the barb in the width direction.

[0009] In one embodiment, the width H of the barb and the groove depth H1 satisfy: 1 / 6·H≤H1≤1 / 4·H.

[0010] In one embodiment, the groove depth H1 and the groove width B1 satisfy: H1≤B1≤1 / 2·H1.

[0011] In one embodiment, the joint includes a barb that passes through the covering film and is inclined at 20° to 50° relative to the extension direction of the barbs.

[0012] In one embodiment, the tip angle θ1 of the barb satisfies: 15°≤θ1≤20°; the distance L1 from the root of the barb to the root of the barb and the length L of the barb satisfy: 1 / 3·L≤L1≤1 / 2·L.

[0013] In one embodiment, the barbs are one or more, with at least one of the barbs distributed on the side of the barb in the width direction.

[0014] In one embodiment, the joint includes a resilient seal that is tightly covered by the coating.

[0015] In one embodiment, the bonding portion includes a narrow membrane, the covering film completely covering the narrow membrane, and the outer portion of the covering film covered by the narrow membrane is wrapped with binding wire.

[0016] The covered stent provided by the present invention enhances the bonding effect between the covering and the barbs by setting a connecting part at the base of the barbs. The connecting part fully contacts the barbs and the covering. When using traditional heat treatment process for bonding, it can also reduce or prevent the barbs and the covering from separating from each other during the rebound of the barbs, thereby preventing blood from entering the interior of the covering through the gap and then contacting the bare stent, which would affect the overall performance and lifespan of the covered stent. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a film-coated scaffold in the prior art;

[0018] Figure 2 This is a schematic diagram of the structure of barbs in the prior art;

[0019] Figure 3 This is a schematic diagram of the sheathing process of a film-coated stent in the prior art;

[0020] Figure 4 This is a schematic diagram of the state of barbs in existing technology;

[0021] Figure 5 This is a schematic diagram of the release process of the barbs in existing technology;

[0022] Figure 6 This is a schematic diagram of the state of the barbs in Example 1;

[0023] Figure 7 This is a schematic diagram of the state of the barbs in Example 2;

[0024] Figure 8 yes Figure 7 Enlarged view of region A in the middle;

[0025] Figure 9 This is a schematic diagram of the barb structure in Example 3;

[0026] Figure 10 yes Figure 9 Enlarged view of region B in the middle;

[0027] Figure 11 This is a schematic diagram of the state of the barbs in Example 4;

[0028] Figure 12 This is a schematic diagram of the state of the barbs in Example 5. Detailed Implementation

[0029] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0030] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] In the field of interventional medical devices, the proximal end of an implant (such as a stent) after deployment is typically defined as the end closer to the heart and the distal end as the end farther from the heart. "Axial" generally refers to the length direction of the implant during delivery, while "radial" generally refers to the direction perpendicular to the implant's "axial" direction. Based on this principle, the "axial" and "radial" of any component of the implant are defined.

[0033] To better illustrate the innovative aspects of this invention, we will first introduce the existing technology.

[0034] Existing technology:

[0035] like Figure 1-5 As shown, Figure 1 This is a schematic diagram of the structure of the covered scaffold 100 in the prior art. Figure 2 This is a schematic diagram of the structure of the barb 11 in the prior art. Figure 3 This is a schematic diagram of the sheathing process of the covered stent 100 in the prior art. Figure 4 This is a schematic diagram of the state of barbs 11 in the existing technology. Figure 5 This is a schematic diagram of the release process of the barb 11 in the prior art.

[0036] The covered stent 100 includes a bare stent 10 and a covering 20. The bare stent 10 is made of a biocompatible material, such as nickel-titanium or stainless steel. Generally, the bare stent 10 includes multiple spaced metal coils. The covering 20 is made of a biocompatible polymer material, such as PTFE, FEP, or PET. To increase the anchoring ability of the covered stent 100 after implantation, a barb 11 is typically placed on a metal coil near the proximal end of the bare stent 10 to enhance its anchoring ability. The barb 11 has a pointed tip, which facilitates its anchoring in the blood vessel. The extension direction of the barb 11 is inclined relative to the axis of the bare stent 10 (i.e., the axis of the covered stent 100), and the angle between the barb 11 and the bare stent 10 is α.

[0037] like Figure 3 As shown, when the covered stent 100 is inserted into the sheath 200, the covered stent 100 will gradually compress into the interior of the sheath 20. Since the distance from the free end of the barb 11 to the longitudinal central axis of the bare stent 10 is slightly greater than the distance from the covered stent 200 to the longitudinal central axis of the bare stent 10, the free end of the barb 11 is located on the outside of the covered stent 20.

[0038] like Figure 4 As shown, the coating 20 covers the surface of the bare support 10, the root of the barb 11 is connected to the bare support 10, and the free end of the barb 11 passes through the coating 20. This is because the existing production process first covers the bare support 10 with the coating 20, then uses a special tool to push the barb 11 out from the outer surface of the coating 20, and finally heat-treats the coating 20 to bond the coating 20 to the bare support 10 and the root of the barb 11. In other words, the coating 20 partially covers the root of the barb 11.

[0039] Combined with appendix Figure 5 To provide further explanation, such as Figure 5 As shown, the barb 11 includes a first state 11a and a second state 11b. The first state 11a of the barb 11 is the compressed state in the sheath, and the second state 11b is the released state of the barb 11. When the covered stent 100 is released, the barb 11 changes from the first state 11a to the second state 12a. It should be noted that the barb 11 and the bare stent 10 are made of the same material, which is a metal material with memory capacity. The covering 20 covers the bare stent 10 and moves with the movement of the bare stent 10. Therefore, during the release process of the covered stent 100, the movement of the bare stent 10 and the barb 11 drives the movement of the covering 20.

[0040] However, during the transport process, the barb 11 is in the first state 11a, with the first side 111 of the barb 11 (i.e., the inner side near the bare support 10) pressing against the film 20 at the distal end of the barb 11 root, and the second side 112 of the barb 11...

[0041] (i.e., the outer side away from the bare stent 10) tighten the cover 20 at the proximal end of the root. During the release process, the barb 11 rebounds rapidly, changing from the first state 11a to the second state 12a. At this time, the first side of the root of the barb 11 quickly moves away from the cover 20 at the distal end of the root of the barb 11, and the second side of the root of the barb 11 quickly moves closer to the cover 20 at the proximal end of the root of the barb 11. Since the barb 11 and the cover 20 are only bonded by heat treatment, during such rapid rebound of the barb 11, the root of the barb 11 is prone to detach from the cover 20, resulting in a gap between the barb 11 and the cover 20. This allows blood to enter the cover 20 and contact the bare stent 10, thereby affecting the performance and lifespan of the covered stent 100.

[0042] Therefore, in order to solve the problems existing in the prior art, the present invention adopts a variety of implementation methods.

[0043] Example 1

[0044] like Figure 6 As shown, Figure 6 This is a schematic diagram of the state of the barbs 21 in Embodiment 1. In Embodiment 1, the bare stent 10 includes multiple spaced metal coils made of biocompatible materials such as nickel-titanium or stainless steel. The covering 20 covers the surface of the bare stent 10 and is made of a biocompatible polymer material such as PTFE, FEP, or PET. The base of the barbs 21 connects to the bare stent 10, and the free end of the barb 21 passes through the covering 20 and is exposed. The tail end of the barb 21 is pointed, which is beneficial for anchoring the barb 21 in the blood vessel. The extension direction of the barb 21 is inclined relative to the axis of the bare stent 10 (i.e., the axis of the covered stent 100). The angle between the barb 21 and the bare stent 10 is β, which satisfies 20° < β < 50°. When the β angle is too small, the anchoring force of the barb 21 is small, and the covered stent is prone to displacement; when the β angle is too large, the barb 21 will generate large stress at the base of the barb during the sheathing compression process, affecting the quality of the covered stent.

[0045] The root of the barb 21 is wound with a filament 22. The material of the filament 22 should have good biocompatibility. This material can be a polymer material or a metal material, such as a PTFE film, a PTFE wire, a tantalum wire, a nitinol wire, etc. The filament 22 and the barb 21 can be an integral structure or formed by welding. The part of the film 20 covering the root of the barb 21 is the film 23. The film 23 is covered on the surface of the filament 22. Since the filament 22 is wound around the root of the barb 21, part of the root position of the barb 21 is exposed, and part is covered by the filament 22, presenting an uneven structure as a whole. The film 23 covers the root position of the barb 21. During the heat treatment bonding, the film 23 closely adheres to the surface of the filament 22 and the root of the barb 21, resulting in the film 23 being able to closely contact the rough root surface formed by the barb 21 and the filament 22, making the film 23 tightly adhere to the root position of the barb 21. Thus, during the release process, the barb 21 will not break away from the film 23, causing a gap to form between the barb 21 and the film 23. The relationship between the length L of the barb 21 and the length L1 of the filament 22 must satisfy L > L1. Because when the length L1 of the filament 22 is too short, it cannot effectively ensure that the film 23 moves together with the barb 21 during the compression and rebound of the barb 21. Therefore, in this embodiment, the relationship between the length L of the barb 21 and the length L1 of the filament 22 is preferably 0.5·L < L1 < L (in order to facilitate the distinction between codes and numbers, the multiplication sign between numbers and codes is represented by "·", the same below), and the filament 22 is completely covered by the film 23.

[0046] Embodiment 2

[0047] The same parts of Embodiment 2 and Embodiment 1 will not be elaborated here. The differences are that in Embodiment 2, no filament is used. For specific reference, Figure 7-8 , Figure 7 is a schematic structural view of the barb 31 in Embodiment 2, Figure 8 is Figure 7 an enlarged view of area A in

[0048] A plurality of grooves 32 are provided on the side surface of the root (or the whole) of the barb 31. The specific shape of the grooves 32 is not limited, including wavy, spiral, etc. In this embodiment, the wavy shape is selected. The grooves 32 are formed by laser processing. To ensure the strength of the barb 31, the grooves 32 located on different side surfaces are offset from each other.

[0049] For the barb 31, the length of the barb 31 is L, the width is H, the distribution length of the grooves 32 on the barb 31 is L2, the groove depth is H1, the groove width is B1, and the groove spacing between adjacent grooves is B2. To achieve a better fit, the following conditions must be met:

[0050] Regarding the selection of groove depth H1, if groove depth H1 is too small, the embedding effect of the coating 24 and the barb 31 support will not be ideal; if H1 is too large, it will reduce the strength of the barb 31 too much. Therefore, it is necessary to satisfy 1 / 6·H≤H1≤1 / 4·H.

[0051] Regarding the selection of the groove width B1, both excessively large and small groove widths will affect the embedding effect between the coating 24 and the barb 31. If the groove depth H1 remains constant, and the groove width B1 is too small, the coating 24 will be difficult to embed into the groove 32. If the groove width B1 is too large, the uneven portion will be too small when the coating 24 and the barb 31 are joined, resulting in a poor bonding effect. Therefore, the relationship between the groove width B1 and the groove depth H1 is: H1 ≤ B1 ≤ 1 / 2·H1.

[0052] The relationship between the groove spacing B2 and the groove width B1 is: B1≤B2≤1.5·B1. This is because if the groove spacing B2 is too small, it will affect the strength of the barb 31. If the groove spacing B2 is too large, when the coating 24 and the barb 31 are combined, there will be too few uneven parts, resulting in a poor bonding effect between the barb 31 and the coating 24.

[0053] Furthermore, to ensure the bonding performance between the coating 24 and the barb 31, the relationship between the groove distribution length L2 and the barb 31 length L is: 0.5·L≤L2≤0.75·B1. If the groove distribution length L2 is too large, that is, the distribution area of ​​the groove 32 is too large, it will affect the strength of the tip of the barb 31, causing the barb 31 to be prone to breakage during compression and rebound, thus affecting the anchoring effect of the barb 31. On the other hand, if the groove distribution length L2 is too short, the bonding effect between the coating 24 and the barb 31 will not be ideal.

[0054] In another embodiment, the barb 31 includes four sides in four directions. In addition to the first side 111 (i.e., the inner side close to the bare support) and the second side 112 (i.e., the outer side away from the bare support) mentioned above, it also includes a third side and a fourth side located between the first side 111 and the second side 112. It should be noted that the first side 111 and the second side 112 are the two sides in the thickness direction of the barb 31, and the third side and the fourth side are the two sides in the width direction of the barb 31. The groove 32 of the barb 31 can only be provided on the third side and the fourth side of the barb 31. If multiple grooves 32 are provided on the surface of the first side 111 and the second side 112 of the barb 31, the thickness of the barb 31 will be reduced, resulting in insufficient strength of the barb 31. During the contraction and rebound of the covered stent, the barbs 31 are actually moving closer to and further away from the bare stent 10. The insufficient strength of the first side 111 and the second side 112 of the barbs 31 can easily cause the barbs 31 to break, thereby affecting the anchoring strength of the barbs 31. This makes the covered stent prone to displacement after vascular release, affecting the medical effect of the vascular covered stent.

[0055] Example 3

[0056] The parts of Example 3 that are the same as those of Example 2 will not be repeated here. The difference is that Example 3 uses a new barb structure, such as... Figure 9-10 As shown, Figure 9 This is a schematic diagram of the barb 41 in Example 3. Figure 10 yes Figure 9 An enlarged schematic diagram of region B. Barbs 41 are disposed on the bare support 10, with a coating 25 covering the base of the barbs 41. Hangers 42 for attaching the coating 25 are provided on the barbs 41, located on the third and fourth sides of the barbs 41. Their purpose is to prevent the barbs 41 from puncturing the coating on the bare support 10 during compression and release. The hangers 42 can be laser-cut or welded to the sides of the barbs 41.

[0057] In this embodiment, the length of the barb 41 is L, the distance from the root of the hook 42 to the root of the barb 41 is L1, the tilt angle of the hook 42 relative to the barb 41 is θ, the tip angle of the hook 42 itself is θ1, the thickness of the coating 25 is H, and the distance from the free end (i.e., tip) of the hook 42 to the outer surface of the barb 41 is H1. To achieve a better fit, the following conditions must be met:

[0058] To prevent the coating 25 at the base of the barb 41 from separating from the barb 41 during compression and rebound, thus creating a gap between the barb 41 and the coating 25, the stability of the coating at the base of the barb 41 must be ensured. Therefore, the distance L1 from the base of the barb 42 to the base of the barb 41 and the length L of the barb 41 must satisfy the following: 1 / 3·L≤L1≤1 / 2·L. If L1 is too small, the coating effect at the base of the barb 41 will not be obvious. If L1 is too large, the coating 25 needs to be stretched to hang on the barb structure. When the coating 25 is stretched, its thickness will decrease, which will reduce the strength of the coating 25. During the compression and rebound of the barb 41, the coating 25 will be easily torn.

[0059] Regarding the tip angle θ1 of the piercing 42, if θ1 is too small, the tip strength of the piercing 42 is insufficient, and it is easy to break when the piercing 42 pierces the coating 25. If θ1 is too large, the coating 25 is difficult to be pierced and hung on the structure by the piercing 42. Therefore, the tip angle of the piercing 42 preferably satisfies: 15°≤θ1≤20°.

[0060] For the tip of the barb 42, it is sufficient for the barb 42 to be able to hook the coating 25. However, if the distance H1 from the free end (i.e. the tip) of the barb 42 to the outer surface of the barb 41 is too small, it will be difficult for the coating 25 to be hooked onto the barb 42, and it will be difficult to guarantee the bonding effect between the coating 25 and the barb 41. Therefore, the distance H1 from the free end (i.e. the tip) of the barb 42 to the outer surface of the barb 41 is preferably satisfied as follows: 1.5·H≤H1≤2·H;

[0061] Regarding the tilt angle θ of the barbed wire 42, if the angle is too small, the coating 25 will be difficult to attach to the barbed wire 42; if the angle is too large (close to 90°), the barbed wire 42 will only pass through the coating 25 and will not be able to play a attaching role. When θ1 reaches a right angle or even an obtuse angle, that is, when the barbed wire 42 is equivalent to the barb of the barb 41, the barb 41 will be compressed, which will cause the barbed wire 42 to easily pierce the coating 25. Therefore, the preferred tilt angle θ of the barbed wire 42 is: 20°≤θ≤50°.

[0062] Example 4

[0063] The parts of Example 4 that are the same as those in Example 1 will not be repeated here. The difference is that Example 4 uses a new barb structure, which can be found in the appendix of the instruction manual. Figure 11 As shown, Figure 11 This is a schematic diagram of the state of the barbs 51 in Embodiment 4. The film 26 covers the surface of the bare support 10 and the root of the barbs 51. An elastic seal 52 is provided at the root of the barbs 51. The elastic seal 52 is made of a material with good biocompatibility, elasticity, sealing performance, toughness and softness, such as silicone.

[0064] Because the elastic seal 52 has good toughness and elasticity, it can move with the barb 51 during compression and rebound, ensuring a tight fit between the elastic seal 52 and the root of the barb 51. The surface of the elastic seal 52 is also tightly covered by the membrane 26. When a gap appears between the root of the barb 51 and the membrane 26, the bottom of the gap is sealed by the elastic seal 52. The elastic seal 52 itself is covered by the membrane 26, thus reducing or even preventing blood from entering the membrane 26 and contacting the bare stent 10 due to a gap between the root of the barb 51 and the membrane 26, thereby affecting the performance and lifespan of the covered stent.

[0065] Example 5

[0066] The parts of Example 5 that are the same as those of Example 1 will not be repeated here. The difference is that Example 5 uses a new barb structure, which can be found in the appendix of the instruction manual. Figure 12 As shown, Figure 12 This is a schematic diagram of the state of the barb 61 in Embodiment 5. The covering film 27 covers the surface of the bare support 10 and the root of the barb 61. A narrow film 63 is provided at the root of the barb 61. The narrow film 63 is close to the root of the barb 61. The covering film 27 completely covers the narrow film 63 and simultaneously covers the root of the barb 61. At the root of the barb 61, several threads 62 are wound on the covering film 27. The threads 62 are made of a polymer material with good biocompatibility. In this embodiment, PTFE is used.

[0067] At the root of the barb 61, since the narrow membrane 27 is located inside the coating 27, the coating 27 is squeezed outward. With the fixation of the wire 62, the barb 61 and the coating 27 are not easily separated from each other in the coating support formed after heat treatment.

[0068] The narrow membrane 63 is designed because the coating 27 is generally of uniform thickness, making it difficult to achieve the desired thickness at the root of the barb 61. Since the narrow membrane 63 is made of the same material as the coating 27, after final heat treatment, the narrow membrane 63 and the coating 27 are completely bonded together to form an integral structure. Therefore, the narrow membrane 63 enhances the elasticity and resilience of the coating 27 at the root of the barb 61, significantly improving the sealing performance of the coating 27 at the root of the barb 61 and effectively solving the problem of gaps appearing between the coating 27 and the barb 61 during the barb 61's rebound due to poor adhesion.

[0069] In another embodiment, the narrow membrane 63 and the coating 27 are made of different materials, and after heat treatment, the narrow membrane 63 and the coating 27 are tightly bonded together.

[0070] In another embodiment, the narrow film 63 is wound with filaments and then bonded to the covering film 27, further enhancing the bonding effect of the narrow film 63 and the covering film 27.

[0071] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should also be noted that in the above embodiments, the filaments, grooves, barbs, narrow membranes, etc., provided at the root of the barb are all joints designed to enhance the bonding effect between the root of the barb and the coating.

[0072] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A covered stent, comprising a stent body, a covering, and a plurality of barbs disposed on the stent body, wherein the stent body includes a natural state without being subjected to other external forces and a compressed state after loading, characterized in that, The coating covers the support body, the barbs include a joint located at the root of the barbs, the coating covers the support body and at least part of the joint, the joint includes a filament wrapped around the root of the barb, the filament being located between the coating and the barb, or the joint includes an elastic seal tightly covered by the coating.

2. The covered stent according to claim 1, characterized in that, The joint includes a filament, the length of which is greater than 0.5 times the length of the barb and less than the length of the barb.

3. The covered stent according to claim 1, characterized in that, The joint includes multiple grooves, which are staggered and distributed on the side of the barb in the width direction.

4. The covered stent according to claim 3, characterized in that, The width H of the barb and the groove depth H1 satisfy: 1 / 6·H≤H1≤1 / 4·H.

5. The covered stent according to claim 3, characterized in that, The groove depth H1 and the groove width B1 satisfy: H1≤B1≤1 / 2·H1.

6. The covered stent according to claim 1, characterized in that, The joint includes a barb that passes through the covering film and is inclined at 20° to 50° relative to the extension direction of the barbs.

7. The covered stent according to claim 6, characterized in that, The tip angle θ1 of the barb satisfies: 15°≤θ1≤20°; the distance L1 from the root of the barb to the root of the barb and the length L of the barb satisfy: 1 / 3·L≤L1≤1 / 2·L.

8. The covered stent according to claim 6, characterized in that, The barbs may be one or more, with at least one of the barbs distributed on the side of the barb in the width direction.

9. The covered stent according to claim 1, characterized in that, The joint includes a narrow membrane, the covering film completely covers the narrow membrane, and the outer part of the covering film is wrapped with binding wire.

10. The covered stent according to claim 9, characterized in that, The narrow membrane is made of the same material as the coating.

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