A vascular stent and a stent assembly

Abstract

The present invention relates to the technical field of medical devices, and in particular to a vascular stent and a stent assembly. A vascular stent provided by the present invention includes an open-loop stent and a first closed-loop stent. The open-loop stent is connected to the first closed-loop stent, and the first closed-loop stent is used to anchor blood vessels and can be retrieved; the first closed-loop stent includes a first support beam, and the first support beam has a first width in the axial direction of the first closed-loop stent. The open-loop stent includes a second support beam, and the second support beam has a second width in the axial direction of the open-loop stent. The first width is less than the second width, so that the first closed-loop stent and the open-loop stent have the same supporting force. The vascular stent extends out of the release tube. The closed-loop stent first extends into the blood vessel. Before the closed-loop stent is completely pushed out of the release tube, the vascular stent can be retrieved into the release tube. The width of the first support beam is less than the width of the second support beam, so that the closed-loop stent and the open-loop stent have the same supporting force and flexibility.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a vascular stent and a stent assembly. Background Art

[0002] Intracranial aneurysm is a cerebrovascular disease with a high disability rate and a high fatality rate. Clinically, there are two ways to treat intracranial aneurysms: surgical clipping and endovascular interventional treatment. Surgical operation has the advantages of low recurrence rate and low probability of complications, but it has large trauma and a long recovery period, and is not suitable for aneurysms in some complex positions and patients with poor physical conditions. Endovascular interventional treatment is increasingly applied clinically because of its small trauma and wide indications. Endovascular interventional treatment mainly uses embolization-assisted stents and has achieved good therapeutic effects clinically.

[0003] For the existing types of vascular stents used to treat intracranial aneurysms, according to the shape of the window formed after connection, the vascular stent can be divided into an open-loop structure vascular stent and a closed-loop structure vascular stent. The closed-loop structure design means that there are connecting ribs between each minimum circumferential symmetric unit of adjacent support rings in the stent. The open-loop structure design means that each minimum circumferential symmetric unit of adjacent support rings of the stent is entirely connected by connecting ribs. The characteristic of the open-loop structure is good flexibility and easy passage through the tortuous intracranial blood vessels. However, once the release starts, it cannot be retrieved into the release catheter. The characteristic of the closed-loop structure is that the whole stent can be retrieved, but it is easy to bend in the blood vessel. The existing products are usually of a unified open-loop structure design or closed-loop structure design, which results in that the vascular stent cannot have both flexibility and retrievability.

[0004] To solve the above problems, in the prior art, the vascular stent is set as a hybrid structure of open-loop and closed-loop. The support beams form a closed-loop stent segment and an open-loop stent segment respectively through a closed-loop connection method or an open-loop connection method. The closed-loop stent segment first extends into the blood vessel. When it is determined that the position of the plaque does not match the actual position, the guide wire can be retrieved, and at the same time, the open-loop stent segment is not easy to bend. However, in this solution, since the closed-loop stent segment and the open-loop stent segment adopt different connection methods, the supporting force of the closed-loop stent segment is greater than that of the open-loop support segment, resulting in inconsistent flexibility of the whole vascular stent and difficult passage through the tortuous intracranial blood vessels. Summary of the Invention

[0005] The purpose of the present invention is to provide a vascular stent and a stent assembly to solve the technical problem that the supporting force of the closed-loop stent segment is greater than that of the open-loop support segment, resulting in inconsistent flexibility of the whole vascular stent.

[0006] A vascular stent provided by the present invention includes an open-loop stent and a first closed-loop stent. The open-loop stent is connected to the first closed-loop stent. The first closed-loop stent is used to anchor blood vessels and can be retrieved.

[0007] The first closed-loop stent includes a first support beam, and the first support beam has a first width in the axial direction of the first closed-loop stent. The open-loop stent includes a second support beam, and the second support beam has a second width in the axial direction of the open-loop stent. The first width is less than the second width, so that the first closed-loop stent and the open-loop stent have the same supporting force.

[0008] As a further technical solution, a plurality of the first support beams are connected end to end in sequence to form a minimum support unit, and the first closed-loop stent includes a plurality of the minimum support units.

[0009] As a further technical solution, six of the first support beams form the minimum support unit. When the minimum support unit is in a quadrilateral shape, it has a long side and a short side. The long side includes two of the first support beams, and the short side includes one of the first support beams.

[0010] One of the first support beams on the long side is shared with the short side of an adjacent minimum support unit, and the other first support beam is shared with the long side of another adjacent minimum support unit.

[0011] As a further technical solution, the second support beams are connected end to end in sequence to form a first annular support body, and the axial direction of the first annular support body is corrugated. The open-loop stent includes a plurality of the first annular support bodies and a first connecting rod. Adjacent first annular support bodies are connected by the first connecting rod.

[0012] As a further technical solution, between adjacent first annular support bodies, the peak of one first annular support body corresponds to the peak of another first annular support body, and the trough of one first annular support body corresponds to the trough of another first annular support body.

[0013] As a further technical solution, it further includes a second connecting rod. A plurality of the second connecting rods are connected end to end in sequence to form a second annular support body, and the axial direction of the second annular support body is corrugated.

[0014] The first closed-loop stent is connected to the open-loop stent through the second annular support body.

[0015] As a further technical solution, a developing structure is further included. Both the open-loop stent and the first closed-loop stent are provided with the developing structure, and the developing structure is used to track the positions of the open-loop stent and the first closed-loop stent in the blood vessel.

[0016] As a further technical solution, the invention further comprises a second closed-loop bracket, wherein the second closed-loop bracket is connected to the open-loop bracket and is located on a side of the open-loop bracket away from the first closed-loop bracket;

[0017] The second closed-loop support includes a third support beam, which has a third width in the axial direction of the second closed-loop support. The third width is smaller than the second width, so that the second closed-loop support and the open-loop support have the same flexibility and support force.

[0018] The present invention provides a stent assembly, comprising the aforementioned vascular stent, a catheter, and a guide wire. The vascular stent is inserted into the catheter, and the guide wire is inserted into the vascular stent.

[0019] As a further technical solution, a second imaging structure is provided on the guide wire, and the second imaging structure is used to track the release progress of the vascular stent.

[0020] Compared with the prior art, the vascular stent provided by the present invention has the following technical advantages:

[0021] The vascular stent provided by the present invention includes an open-loop stent and a first closed-loop stent, the open-loop stent is connected to the first closed-loop stent, the first closed-loop stent is used to anchor the blood vessel and can be recovered; the first closed-loop stent includes a first support beam, and the first support beam has a first width in the axial direction of the first closed-loop stent, the open-loop stent includes a second support beam, and the second support beam has a second width in the axial direction of the open-loop stent, the first width is smaller than the second width, so that the first closed-loop stent and the open-loop stent have the same supporting force.

[0022] When the vascular stent is extended from the release tube, the first closed-loop stent is first extended into the blood vessel and expands outward due to its own elasticity to act as an anchor. Before the first closed-loop stent is completely pushed out of the release tube, if the anchoring position is not good, the vascular stent can be recovered into the release tube, adjusted and released again; the width of the first support beam is smaller than the width of the second support beam, so that the supporting force of the first closed-loop stent is reduced, so that the first closed-loop stent has the same supporting force as the open-loop stent, and thus the overall flexibility of the vascular stent is the same, making it easier to pass through the complex and curved intracranial blood vessels.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a schematic plan view of the vascular stent provided by the embodiment of the present invention after being longitudinally deployed.

[0026] Reference numerals: 1 - first closed-loop stent; 2 - second annular support; 3 - open-loop stent; 4 - second closed-loop stent; 5 - first support beam; 6 - second connecting rod; 7 - second support beam; 8 - first connecting rod; 9 - third support beam; 10 - first annular support. Specific Embodiments

[0027] The following will clearly and completely describe the technical solutions of the present invention in combination with the embodiments. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0030] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or is unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0031] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0032] The specific structure is as Figure 1 shown.

[0033] This embodiment provides a vascular stent, which includes an open-loop stent 3 and a first closed-loop stent 1. The open-loop stent 3 is connected to the first closed-loop stent 1, and the first closed-loop stent 1 is used to anchor the blood vessel and can be retrieved.

[0034] The first closed-loop stent 1 includes a first support beam 5, and the first support beam 5 has a first width in the axial direction of the first closed-loop stent 1. The open-loop stent 3 includes a second support beam 7, and the second support beam 7 has a second width in the axial direction of the open-loop stent 3. The first width is smaller than the second width, so that the first closed-loop stent 1 and the open-loop stent 3 have the same supporting force.

[0035] In this embodiment, the vascular stent is integrally in a tubular structure with a thickness of 0.02 mm - 0.2 mm. The vascular stent is made of a superelastic material, nitinol alloy, so that the vascular stent can automatically expand to fit the blood vessel wall after being released. The nitinol alloy tube is made by processes such as laser engraving and chemical etching, and then heat-treated to a target diameter, and then pickled, polished and other processes are used to remove the defects generated on the surface during the processing. The front part is the first closed-loop stent 1 designed with a closed-loop structure, and the rear part is the open-loop stent 3 designed with an open-loop structure. When the vascular stent is extended from the release tube, the first closed-loop stent 1 first extends into the blood vessel, and the first support beam 5 expands outward to contact the blood vessel, playing an anchoring role. Before the first closed-loop stent 1 is completely pushed out of the release tube, it can be retrieved into the release tube. If the anchoring position is not good, the vascular stent can be retrieved into the release tube, adjusted and then released again.

[0036] In this embodiment, the width of the first support beam 5 is smaller than that of the second support beam 7. In the circumferential direction, the supporting force of the first support beam 5 is smaller than that of the second support beam 7. The first support beams 5 are connected in a closed-loop manner to form the first closed-loop stent 1, and the second support beams 7 are connected in an open-loop manner to form the open-loop stent 3. Since the structure under the closed-loop connection is more compact and has a stronger supporting force than the structure under the open-loop connection as a whole, the first closed-loop stent 1 and the open-loop stent 3 have the same supporting force, making the overall compliance of the vascular stent the same, and it is easier to pass through the intracranial blood vessels with complex curvatures. At the same time, when released in the intracranial blood vessels with a smaller radius of curvature, it is not easy to have excessive bending resulting in the buckling of the vascular stent and the narrowing of the channel.

[0037] In this embodiment, the first closed-loop stent 1 accounts for 1 / 8 to 1 / 2 of the length of the overall vascular stent. When the first closed-loop stent 1 of such a length is tentatively extended, due to its sufficient length, the front part of the first closed-loop stent 1 can play an anchoring role, and at the same time, the rear part has not been fully released, enabling the first closed-loop stent 1 to not only play an anchoring role but also be convenient for recovery.

[0038] Preferably, in this embodiment, the first closed-loop stent 1 accounts for 1 / 4 of the length of the overall vascular stent, making the overall performance of the vascular stent better.

[0039] In an alternative technical solution of this embodiment, multiple first support beams 5 are connected end to end in sequence to form the minimum support unit, and the first closed-loop stent 1 includes multiple minimum support units.

[0040] In this embodiment, the minimum support unit is rotationally symmetric by 180° with respect to its geometric center, and multiple minimum support units form the first closed-loop stent 1.

[0041] In an alternative technical solution of this embodiment, six first support beams 5 form the minimum support unit. When the minimum support unit is in a quadrilateral shape, it has a long side and a short side. The long side includes two first support beams 5, and the short side includes one first support beam 5.

[0042] In the first implementation manner of this embodiment, one of the first support beams 5 on the long side is shared with the long side of an adjacent minimum support unit, and the other first support beam 5 is shared with the long side of another adjacent minimum support unit. In this way, the overall structure is neat, and at the same time, it is convenient for the overall expansion and contraction of the first closed-loop stent 1, and the pores are small when contracting.

[0043] In the first implementation manner of this embodiment, one of the first support beams 5 on the long side is shared with the short side of an adjacent minimum support unit, and the other first support beam 5 is shared with the long side of another adjacent minimum support unit. In this way, it also has the technical advantages and effects of the above implementation manner. At the same time, the pores are smaller after contraction, and it can be compressed to a smaller diameter, which is convenient for delivery in the blood vessels.

[0044] In an alternative technical solution of this embodiment, the second support beams 7 are connected end to end in sequence to form a first annular support body 10, and the axis of the first annular support body 10 is corrugated. The open-loop stent 3 includes a plurality of first annular support bodies 10 and first connecting rods 8, and adjacent first annular support bodies 10 are connected by first connecting rods 8.

[0045] In this embodiment, the corrugations on the first annular support body 10 are periodically symmetric in the circumferential direction. Without considering the first connecting rod 8, the number of corrugation cycles is 6 - 18. In this way, the first annular support body 10 can better support the blood vessel and is convenient for contraction and dilation. Preferably, the number of corrugation cycles is 8, and such a number of corrugations can make the effect of the first annular support body 10 optimal.

[0046] In this embodiment, adjacent first annular support bodies 10 are connected by a plurality of first connecting rods 8. Preferably, the number of first connecting rods 8 is two, and the two connecting rods are symmetric with respect to the axis of the blood vessel stent. In this way, the blood vessel stent can have high flexibility both after being crimped and released, which helps to pass through the curved blood vessel and can also fit well with the blood vessel wall after being released.

[0047] In this embodiment, the first connecting rod 8 can be straight, V-shaped, S-shaped, Z-shaped, W-shaped or N-shaped, as long as it meets the actual requirements.

[0048] Furthermore, between adjacent first annular support bodies 10, the peak of one first annular support body 10 corresponds to the peak of another first annular support body 10, and the trough of one first annular support body 10 corresponds to the trough of another first annular support body 10. This design enables the blood vessel stent not to contact or overlap between adjacent waveforms when bending, effectively avoiding mutual extrusion, preventing endothelial cell damage and restenosis of the blood vessel stent.

[0049] It should be noted that the peaks and troughs can also adopt other corresponding methods, and this embodiment is not limited thereto.

[0050] In an alternative technical solution of this embodiment, it further includes a second connecting rod 6. One end of the second connecting rod 6 is connected to the first closed-loop stent 1, and the other end is connected to the open-loop stent 3, and the second connecting rod 6 is connected in a staggered manner, so that a smooth transition is formed between the first closed-loop stent 1 and the open-loop stent 3, making it easier for the blood vessel stent to pass through the curved diseased blood vessel.

[0051] In this embodiment, a plurality of second connecting rods 6 are connected end to end in sequence to form a second annular support body 2, and the axis of the second annular support body 2 is corrugated. The second annular support body 2 has a better supporting effect and flexibility on the blood vessel, making the transition effect between the first closed-loop stent 1 and the open-loop stent 3 better.

[0052] In this embodiment, the second connecting rod 6 is in a straight line, V-shaped, S-shaped, Z-shaped, W-shaped or N-shaped, as long as it meets the actual requirements. At the same time, the width of the second connecting rod 6 in the axial direction of the vascular stent is less than the first width, so that the vascular stent has the same outer diameter after being compressed, which is beneficial to its delivery in the release catheter.

[0053] In an alternative technical solution of this embodiment, it further includes a radiopaque structure. The open-loop stent 3 and the first closed-loop stent 1 are both provided with a radiopaque structure, and the radiopaque structure is used to track the positions of the open-loop stent 3 and the first closed-loop stent 1 in the blood vessel.

[0054] In this embodiment, there are 1-8 radiopaque structures at each of the front and rear ends of the vascular stent to assist in the positioning of the vascular stent in the blood vessel.

[0055] Preferably, in this embodiment, the front end of the stent includes 3 radiopaque structures, and the rear end of the stent includes 4 radiopaque structures, which is simple in structure and convenient to distinguish under imaging.

[0056] The material of the radiopaque structure is platinum or platinum-tungsten alloy, and it is connected to the vascular stent by means of welding, winding or binding.

[0057] In an alternative technical solution of this embodiment, it further includes a second closed-loop stent 4. The second closed-loop stent 4 is connected to the open-loop stent 3 and is located on the side of the open-loop stent 3 away from the first closed-loop stent 1;

[0058] The second closed-loop stent 4 includes a third support beam 9. The third support beam 9 has a third width in the axial direction of the second closed-loop stent 4, and the third width is less than the second width, so that the second closed-loop stent 4 and the open-loop stent 3 have the same flexibility and support force.

[0059] In this embodiment, at least one section of the second closed-loop stent 4 can be added to the rear end of the vascular stent. The second closed-loop stent 4 is expanded to a trumpet shape by heat treatment to improve the wall attachment at the end and at the same time facilitate the re-passing of the release tube.

[0060] In this embodiment, the widths of the first support beam 5, the second support beam 7, the first connecting rod 8 and the second connecting rod 6 in the axial direction of the vascular stent are 0.01 mm to 0.18 mm.

[0061] A stent assembly provided in this embodiment includes the above-mentioned vascular stent. Thus, the technical advantages and effects achieved by this stent assembly include the technical advantages and effects achieved by the above-mentioned vascular stent, which will not be elaborated here.

[0062] The stent assembly further includes a catheter and a guide wire. The vascular stent is disposed inside the catheter, and the guide wire is disposed inside the vascular stent.

[0063] In an alternative technical solution of this embodiment, a second imaging structure is provided on the guide wire, and the second imaging structure is used to track the release progress of the vascular stent.

[0064] In this embodiment, a closed-loop area is formed at the first closed-loop stent 1 of the vascular stent, a connection area is formed at the second connecting rod 6, an open-loop area is formed at the open-loop stent 3, and an end area is formed at the second closed-loop stent 4. The vascular stent is released mechanically. There are multiple imaging structures corresponding to the boundaries of different areas of the vascular stent on the guide wire to determine the release progress of the vascular stent during the release process, helping the operator to position the vascular stent and its release condition under imaging. The vascular stent is released into the blood vessel through a catheter. First, the vascular stent and the guide wire are compressed and held in the catheter together. From the outside to the inside, they are the catheter, the vascular stent, and the guide wire. The guide wire is connected to the rear end of the vascular stent through a connection and disassembly structure.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vascular stent, characterized in that, Comprising: An open-loop stent (3) and a first closed-loop stent (1), the open-loop stent (3) being connected to the first closed-loop stent (1), the first closed-loop stent (1) being used for anchoring a blood vessel and being retrievable; The first closed-loop stent (1) includes a first support beam (5), and the first support beam (5) has a first width in the axial direction of the first closed-loop stent (1). The open-loop stent (3) includes a second support beam (7), and the second support beam (7) has a second width in the axial direction of the open-loop stent (3). The first width is less than the second width, so that the first closed-loop stent (1) and the open-loop stent (3) have the same supporting force; A plurality of the first support beams (5) are connected end to end in sequence to form a minimum support unit, and the first closed-loop stent (1) includes a plurality of the minimum support units; Six of the first support beams (5) form the minimum support unit. When the minimum support unit is in a quadrilateral shape, it has a long side and a short side. The long side includes two of the first support beams (5), and the short side includes one of the first support beams (5); One of the first support beams (5) on the long side is shared with the short side of an adjacent minimum support unit, and the other first support beam (5) is shared with the long side of another adjacent minimum support unit.

2. The vascular stent according to claim 1, wherein The second support beams (7) are connected end to end in sequence to form a first annular support body (10), and the axial direction of the first annular support body (10) is corrugated. The open-loop stent (3) includes a plurality of the first annular support bodies (10) and first connecting rods (8), and adjacent first annular support bodies (10) are connected by the first connecting rods (8).

3. The vascular stent according to claim 2, wherein, Between adjacent first annular support bodies (10), the peak of one first annular support body (10) corresponds to the peak of another first annular support body (10), and the trough of one first annular support body (10) corresponds to the trough of another first annular support body (10).

4. The vascular stent according to claim 1, characterized in that, It further includes a second connecting rod (6). A plurality of the second connecting rods (6) are connected end to end in sequence to form a second annular support body (2), and the axial direction of the second annular support body (2) is corrugated; The first closed-loop stent (1) is connected to the open-loop stent (3) through the second annular support body (2).

5. The vascular stent according to any one of claims 1-4, characterized in that, It further includes a radiopaque structure. The open-loop stent (3) and the first closed-loop stent (1) are both provided with the radiopaque structure, and the radiopaque structure is used to track the positions of the open-loop stent (3) and the first closed-loop stent (1) in the blood vessel.

6. The vascular stent according to any one of claims 1-4, characterized in that, It further includes a second closed-loop stent (4). The second closed-loop stent (4) is connected to the open-loop stent (3) and is located on the side of the open-loop stent (3) away from the first closed-loop stent (1); The second closed-loop stent (4) includes a third support beam (9), and the third support beam (9) has a third width in the axial direction of the second closed-loop stent (4), and the third width is smaller than the second width, so that the second closed-loop stent (4) and the open-loop stent (3) have the same flexibility and supporting force.

7. A bracket assembly, characterized in that, The vascular stent includes the vascular stent according to any one of claims 1-6, and further includes a catheter and a guide wire. The vascular stent is disposed within the catheter, and the guide wire is disposed within the vascular stent.

8. The stent assembly according to claim 7, wherein, A second imaging structure is provided on the guide wire, and the second imaging structure is used to track the release progress of the vascular stent.

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