Covered stent

Abstract

The utility model provides a covered stent which comprises a covered body and a wave ring and further comprises a covering object and a supporting piece, the covering object and the covered body are fixedly connected to form a bag-shaped structure with an opening, a wave crest or a wave trough penetrates through the opening to be arranged in the bag-shaped structure, and a wave rod can move relative to the bag-shaped structure in the bag-shaped structure. The supporting piece comprises a fixed end and a free end, the fixed end is fixed in the bag-shaped structure, in the process that the covered stent expands from a radial compression state to a radial expansion state, the wave rod and the supporting piece matched with the wave rod move relatively in the bag-shaped structure, the wave rod can be limited between the supporting piece and the covered body or the covering object, and the wave rod is fixed to the supporting piece. Therefore, the covered stent has anchoring property and assembling property.

Description

Technical Field

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

[0002] Aortic aneurysm and aortic dissection are serious diseases that threaten human life. If left untreated, the aortic aneurysm and dissection will continue to grow and eventually rupture, causing serious complications and death. With the increasing number of patients with hypertension, hyperlipidemia and hyperglycemia, the incidence of aortic aneurysm and aortic dissection is also increasing significantly.

[0003] Traditional open surgery for aortic aneurysms and aortic dissections is highly invasive, has a high mortality rate, long operation time, high postoperative complication rate, and is very difficult. Endovascular surgery, on the other hand, is less invasive, has fewer postoperative complications, shorter operation time, and is less difficult, and has gradually become the main method for treating aortic aneurysms and aortic dissections. Endovascular surgery involves implanting a covered stent into the aorta using a delivery device, isolating the vascular lesion outside the covered stent and restricting blood flow through the stent, thereby protecting the blood vessel.

[0004] However, covered stents in related technologies face a trade-off between anchoring and assemblability. On the one hand, covered stents require a certain degree of anchoring, which necessitates a certain radial support strength to anchor them in the body tissue. On the other hand, if the radial support strength is too high, it may not be easily compressible radially, thus hindering assemblage into the sheath. Utility Model Content

[0005] This utility model provides a coated support that combines anchoring and assembly capabilities. The coated support includes a coated body and a wave ring. The wave ring is disposed on the surface of the coated body and includes a wave rod, a wave crest, and a wave trough. The two ends of the wave rod are respectively connected to the wave crest and the wave trough. The coated support includes a radially compressed state and a radially expanded state. The coated support also includes a cover and a support member. The cover is fixedly connected to the coated body to form a bladder-like structure with an opening. The wave crest or the wave trough passes through the opening and is disposed in the bladder-like structure. Within the bladder-like structure, the wave rod can move relative to the bladder-like structure. The support member includes a fixed end and a free end. The fixed end is fixed in the bladder-like structure. When the coated support expands from the radially compressed state to the radially expanded state, the wave rod and the support member that cooperates with the wave rod move relative to each other within the bladder-like structure. The wave rod can be confined between the support member and the coated body or the cover.

[0006] The aforementioned coated support structure, by providing a covering material fixedly connected to the coated body, forms an open, bladder-like structure. Wave crests or troughs pass through the opening and are positioned within this bladder-like structure, thus restricting their position. Simultaneously, the wave rods can move within and relative to the bladder-like structure, increasing the flexibility of the wave rings and facilitating radial compression of the coated support structure for easy assembly into a sheath. Furthermore, the coated support structure also includes a support member, the fixed end of which is fixed within the bladder-like structure. During the expansion of the coated support structure from a radially compressed state to a radially expanded state, the wave rods and the cooperating support member move relative to each other within the bladder-like structure. The wave rods are confined between the support member and the coated body or covering material, thereby increasing the radial support force during the radial expansion state and improving the anchoring stability of the coated support structure.

[0007] In one embodiment, the wave rod within the same capsule structure abuts against one circumferential side of the inner surface of the capsule structure, thereby confining the wave rod within the capsule structure.

[0008] In one embodiment, the wave rod within the same capsule-like structure abuts against the capsule-like structure in the radial direction of the covering support, thereby confining the wave rod between the support member and the covering body or the covering.

[0009] In one embodiment, the radial thickness of the support gradually increases from the free end to the fixed end, and / or the width of the support gradually increases from the free end to the fixed end.

[0010] In one embodiment, at least the middle portion of the surface of the support member has a structure that enhances friction.

[0011] In one embodiment, the surface of the support member is provided with a groove, and the groove is in surface contact with the wave rod.

[0012] In one embodiment, at least one location on the sidewall of the groove abuts against the wave rod.

[0013] In one embodiment, the support member has multiple branches, each of which contacts a different position on the same wave rod.

[0014] In one embodiment, at least half the length of the wave rod is disposed within the sac-like structure.

[0015] In one embodiment, the film body and the covering are made of the same material.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the disclosure of the embodiments of this utility model. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a portion of the covered support structure provided in one embodiment;

[0019] Figure 2 for Figure 1 Enlarged view of section A;

[0020] Figure 3 This is an enlarged view of portion A on the covered support in one embodiment;

[0021] Figures 4 to 6 These are schematic diagrams illustrating the fit between the wave rod and the support member in different embodiments;

[0022] Figure 7 This is an enlarged view of portion A on the covered support in one embodiment;

[0023] Figure 8 This is an enlarged view of part A on the covered stent in one embodiment. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0025] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0027] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0028] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] For ease of description, the terms "proximal" and "distal" are used here as conventional terms in the field of interventional medicine. Specifically, "distal" refers to the end from which blood flows out, and "proximal" refers to the end from which blood flows in. For example, after a covered stent is implanted into the lumen, blood flows from the proximal end of the covered stent toward the distal end. "Axial" refers to its length direction, or the direction in which the interventional device is advanced and de-escalated. "Radial" refers to the direction perpendicular to the "axial" direction.

[0030] Taking blood vessels as an example to illustrate the lumen, the blood vessels may include, but are not limited to, at least one of the following: ascending aorta, aortic arch, descending aorta, thoracic aorta, abdominal aorta, veins, etc. Those skilled in the art should understand that the use of blood vessels as an example is merely illustrative and not intended to limit the scope of this invention. The solutions of this invention are applicable to various human or animal lumens. Human lumens may include, for example, the digestive tract lumen or blood vessels. Various improvements and modifications based on the teachings of this invention are within the protection scope of this invention.

[0031] In this embodiment of the invention, the "wave loop" is a closed or non-closed wave-shaped ring structure, also referred to as a wave-shaped ring structure. It can be disposed on the inner and / or outer wall of the covering body of the covered stent. The wave loop is connected to the covering body by at least one of the following connection methods: suturing, bonding, heat fusion, etc. Exemplarily, at least a portion of the wave loop can be made of a material with good tensile and resilience properties and good biocompatibility. For example, the material includes at least one of the following: known materials used in implantable medical devices, various biocompatible materials, such as alloys of two or more single metals selected from cobalt, chromium, nickel, titanium, magnesium, and iron, stainless steel or nickel-titanium-tantalum alloys, or other biocompatible elastic materials. The wave loop has radial expansion capability, can achieve radial contraction under external force, and after the external force is removed, it self-expands or recovers to its initial shape through mechanical expansion (e.g., balloon expansion) and maintains its initial shape. Thus, after implantation into the lumen, it can adhere tightly to the inner wall of the lumen through its radial support force. The waveform of a wave loop is unrestricted and may include at least one of the following: Z-shaped wave, M-shaped wave, V-shaped wave, sine wave, etc. A wave loop comprises multiple crests, multiple troughs, and wave rods connecting adjacent crests and troughs. A single vertex (crest or trough) and two wave rods connected to that vertex form a wave.

[0032] Understandably, the "wave number" referred to in this embodiment of the invention refers to the number of wave crests or wave troughs. "Wave height" refers to the vertical distance between a wave crest and the adjacent lowest wave trough. "Wave angle" refers to the angle between two adjacent wave rods connecting the same vertex.

[0033] Understandably, radial support force (in N) can be measured using a radial support force tester, such as the Machine Solution Inc (MSI) RX550-100 model. Taking the first wavering as an example, the first wavering is placed inside the radial clamp of the tester. During the test, the radial clamp is kept in place to uniformly compress the first wavering radially until it is compressed to 20% of its original diameter, and the radial support force of the first wavering at this point is measured.

[0034] The radial support force of the first wave of the first test ring is less than that of the second wave of the first test ring, which can be measured by the following method: Construct a first test ring composed of multiple first waves, with the same diameter as the first test ring; construct a second test ring composed of multiple second waves, with the same diameter as the first test ring; test the radial support forces of the first and second test rings respectively, and find that the radial support force of the first test ring is less than that of the second test ring. Since both the first and second waves are on the first test ring, the maximum axial length of the first test ring is the same value, thus it can be calculated that the radial support force of the first wave of the first test ring is less than that of the second wave of the first test ring.

[0035] The radial support strength (unit Pa) mentioned in this embodiment of the invention can be calculated by the following formula: Radial support strength = Radial support force ÷ Maximum axial length of the measured position. It is understood that when multiple corrugations are axially arranged at the measured position, the closer the corrugations are to each other axially, the greater the radial support strength.

[0036] It should be noted that A equals B means that A equals B within the range of assembly and / or installation errors, or that A is approximately equal to B.

[0037] Please refer to Figure 1 In this embodiment, the coating support 100 includes a coating body 1 and a corrugated coil 2. The corrugated coil 2 is disposed on the surface of the coating body 1 and includes a corrugated rod 21, a corrugation crest 22, and a corrugation trough 23. The two ends of the corrugated rod 21 are respectively connected to the corrugation crest 22 and the corrugation trough 23. The coating support 100 includes a radially compressed state and a radially expanded state. In this embodiment, the corrugated coil 2 is disposed on the inner surface of the coating body 1, therefore the corrugated coil 2 is represented by a dashed line. In other embodiments, the corrugated coil 2 may be disposed on the outer surface of the coating body 1.

[0038] See Figure 2 The film-coated support 100 further includes a cover 3 and a support 4. The cover 3 is fixedly connected to the film-coated body 1 to form a capsule-like structure 30 with an opening 31. A wave crest 22 or a wave trough 23 passes through the opening 31 and is disposed in the capsule-like structure 30. Within the capsule-like structure 30, the wave rod 21 can move relative to the capsule-like structure 30. The support 4 includes a fixed end 41 and a free end 42. The fixed end 41 is fixed in the capsule-like structure 30. When the film-coated support 100 expands from a radially compressed state to a radially expanded state, the wave rod 21 and the support 4 that cooperate with the wave rod 21 move relative to each other within the capsule-like structure 30. The wave rod 21 can be confined between the support 4 and the film-coated body 1 or the cover 3.

[0039] In one embodiment, the fixing end 41 is fixed in the capsule structure 30, which can be considered as fixing the fixing end 41 to the film body 1 and / or the covering 3. In one embodiment, the fixing end 41 and the portion near the fixing end in the support member 4 can be fixed to the capsule structure, thereby improving the fixation of the support member 4 to the capsule structure 30. At the same time, the support member 4 is not easily displaced within the capsule structure 30, thus improving support. The fixing method between the covering 3 and the film body 1 can be sewing or gluing, etc. The edges of the covering 3, except for the edge where the opening 31 is located, are sewn to the film body 1, or the edges of the covering 3, except for the edge where the opening 31 is located, are partially sewn to the film body 1. In this embodiment, the covering 3 can be disposed on the inner surface of the film body 1, and is therefore indicated by dashed lines. In other embodiments, the covering 3 can be disposed on the outer surface of the film body 1.

[0040] In the prior art, the wave ring is fixed to the coating body by stitching or gluing. During assembly, the coating bracket 100 needs to be radially compressed. The wave ring is firmly bound by the coating body, which increases the difficulty of radial compression of the wave ring. Furthermore, multiple overlapping wave rings are set to improve anchoring, which further increases the difficulty of radial compression of the wave ring. Therefore, the coating bracket 100 is not easy to be radially compressed, which is not conducive to assembly.

[0041] In this embodiment, the covering 3 and the film body 1 are fixedly connected to form a capsule structure 30 with an opening 31. The wave crest 22 or wave trough 23 passes through the opening 31 and is disposed in the capsule structure 30, thereby restricting the position of the wave crest 22 or wave trough 23. At the same time, the wave rod 21 can move in and relative to the capsule structure 30, improving the flexibility of the wave ring 2 and making the film support 100 easy to be radially compressed for easy assembly into the sheath. In addition, the film support 100 is also provided with a support member 4. The fixed end 41 of the support member 4 is fixed in the capsule structure 30. When the film support 100 expands from the radially compressed state to the radially expanded state, the wave rod 21 and the support member 4 that cooperates with the wave rod 21 move relative to each other in the capsule structure 30. The wave rod 21 can be confined between the support member 4 and the film body 1 or the covering 3, thereby increasing the radial support force in the radially expanded state and improving the anchoring of the film support 100.

[0042] Understandably, the capsule structure 30 replaces the suturing or gluing methods in existing solutions to fix the wavering 2 and the covering body 1, but does not completely fix them, leaving room for relative movement. When it is necessary to assemble it into the sheath to radially compress the covering support 100, adjacent wave rods 21 within the capsule structure 30 move closer to each other to radially compress the wavering 2. During this process, the movement of the wave rods 21 of the wavering 2 relative to the support 4 within the capsule structure 30 allows at least a portion of the wavering 2 to be released from the constraints of the covering body 1 and the support 4, greatly reducing the radial compressive force of the covering support 100 when radially compressing it, and making it easier to assemble the covering support 100 into the sheath. When the covered stent 100 is released in the tissue, it needs to expand from a radially compressed state within the sheath to a radially expanded state during operation. During this process, adjacent wave rods 21 within the capsule structure 30 move away from each other to radially expand the wave ring 2. The adjacent wave rods 21 within the capsule structure 30 enter between the support member 4 and the covered body 1 or the covering 3 and are thus defined, thereby defining the wave ring 2 and the covered body 1. At the same time, when the covered stent 100 is working, the support member 4 increases the radial support force of the wave ring 2, which greatly improves the anchoring performance of the covered stent 100 in the tissue. It should be noted that during the expansion of the membrane support 100 from a radially compressed state within the sheath to a radially expanded state during operation, the wave ring 2 undergoes both radial and circumferential expansion. In this embodiment, the support member 4 has a guiding function. As long as the adjacent wave rods 21 within the capsule structure 30 move away from each other during circumferential expansion of the wave ring 2, and the wave rods 21 contact the free end of the support member 4, they can further extend along the surface of the support member 4 and enter between the support member 4 and the membrane body 1 or the covering 3, thus achieving confinement. In this embodiment, "confinement" can be considered as fixing within a certain range, or more specifically, fixing at a certain point.

[0043] In one embodiment, the wave rod 21 within the same capsule structure 30 abuts against one circumferential side of the inner surface of the capsule structure 30, thereby confining the wave rod 21 within the capsule structure 30. In this embodiment, the wave rod 21 is confined by the capsule structure 30.

[0044] In another embodiment, the wave rod 21 within the same capsule structure 30 abuts against the capsule structure 30 in the radial direction of the covering support 100, thus confining the wave rod 21 between the support member 4 and the covering body 1 or the covering 3. In this embodiment, the wave rod 21 is confined by the space between the support member 4 and the covering body 1 or the covering 3. Further, the radial thickness of the support member 4 gradually increases from the free end 42 to the fixed end 41, and / or, see Figure 3The width of the support member 4 gradually increases from the free end 42 to the fixed end 41, making it easier for the wave rod 21 to enter between the support member 4 and the film body 1 or the covering 3 via the free end 42 of the support member 4. The wave rod 21 can be fixed at a certain position on the support member 4 along the length direction of the support member 4 between the support member 4 and the film body 1 or the covering 3. In one embodiment, at least the middle portion of the surface of the support member 4 has a structure to enhance friction. At the position on the support member 4 with the structure to enhance friction, the support member 4 and the wave rod 21 cannot move relative to each other, thereby controlling the fixed position of the wave rod 21 on the support member 4 to control the radial support force of the wave ring 21.

[0045] In one embodiment, to improve the fit and fixation performance between the support member 4 and the wave rod 21, see... Figures 4 to 6 A groove 43 may be provided on the support member 4, and the groove 43 is in surface contact with the wave rod 21. Furthermore, at least one part of the side wall of the groove 43 abuts against the wave rod 21; see Figure 7 and Figure 8 The support member 4 has multiple branches 40, which contact different positions of the same wave rod 21. The multiple branches 40 of the support member 4 greatly increase the probability that the wave rod 21 contacts the free end of the support member 4, and can then further follow the surface of the support member 4 to enter between the support member 4 and the coating body 1 or the covering 3 and achieve definition.

[0046] In one embodiment, at least half the length of the wave rod 21 is disposed within the sac-like structure 3. This prevents the wave crest 22 or wave trough 23 from detaching from the sac-like structure 3 when the covered stent 100 expands from a radially compressed state to a radially expanded state or vice versa. This would prevent displacement or detachment of the wave ring 2 from the covered body 1, thus ensuring the covered body 1 can effectively isolate blood from tissue and cause blood leakage. In other embodiments, the portion of the wave rod 21 disposed outside the sac-like structure 3 can be connected to the covered body 1 by means of suturing or gluing.

[0047] In this embodiment, the film body 1 and the covering 3 are made of the same material to facilitate manufacturing.

[0048] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A covered stent comprising a covered body and a wave coil, the wave coil being disposed on a surface of the covered body, the wave coil comprising a wave strut, a wave crest and a wave trough, both ends of the wave strut being connected to the wave crest and the wave trough, respectively, the covered stent comprising a radially compressed state and a radially expanded state, characterized in that, The stent further comprises a cover and a support, the cover is fixedly connected with the stent body to form a bag-like structure with an opening, the wave crest or the wave trough is arranged in the bag-like structure through the opening, the wave rod can move relative to the bag-like structure in the bag-like structure, the support comprises a fixed end and a free end, the fixed end is fixed in the bag-like structure; during the expansion of the stent from the radial compression state to the radial expansion state, the wave rod and the support matched with the wave rod move relative to each other in the bag-like structure, and the wave rod can be limited between the support and the stent body or the cover.

2. The stent graft of claim 1, wherein, The wave rod in the same bag-like structure abuts against a circumferential side of an inner surface of the bag-like structure, so that the wave rod is limited in the bag-like structure.

3. The stent of claim 1, wherein The wave rod in the same bag-like structure abuts against the bag-like structure in the radial direction of the stent, so that the wave rod is limited between the support and the stent body or the cover.

4. The stent graft of claim 3, wherein the stent graft is configured to be implanted in a patient's body. The radial thickness of the support gradually increases from the free end to the fixed end, and / or the width of the support gradually increases from the free end to the fixed end.

5. The stent graft of claim 3, wherein the stent graft is configured to be implanted in a patient's body. The surface of at least the middle part of the support has a structure for enhancing friction.

6. The stent graft of claim 3, wherein, The surface of the support is provided with a groove, and the groove is in surface contact with the wave rod.

7. The stent graft of claim 6, wherein the stent graft is configured to be implanted in a patient's body. At least one side wall of the groove abuts against the wave rod.

8. The stent of claim 1, wherein The support has a plurality of branches, and the plurality of branches are respectively in contact with different positions of the same wave rod.

9. The stent of claim 1, wherein At least half of the length of the wave rod is arranged in the bag-like structure.

10. The stent of claim 1, wherein The materials of the stent body and the cover are the same.

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