A tubular stent and stent system comprising the same

Abstract

The present application relates to a kind of tubular stents and the stent system comprising it.The tubular stent includes hollow cylindrical stent body, the stent body has hollow grid, the stent body has the stent free end of integral design along axial extension with stent body;The stent free end is between the proximal end and the distal end of the stent body;Stent auxiliary rod, its proximal end is connected with the stent free end, and the distal end extends to the inside of the stent body.The tubular stent provided in the present application provides functional mechanism for tubular stent by setting stent free end and setting stent auxiliary rod at the distal end of the stent free end, and the connection of stent free end and stent auxiliary rod has the space of deformation to the cavity of tubular stent by the setting of free end plus stent auxiliary rod, does not increase the transport resistance because of the setting of functional mechanism, also does not increase the risk of damage to blood vessel because of the setting of functional mechanism.

Description

Technical Field

[0001] The present invention belongs to the field of vascular stents, and in particular relates to a tubular stent and a stent system comprising the same. Background Art

[0002] Neurointerventional medicine utilizes intravascular catheterization techniques, supported by a digital subtraction angiography (DSA) system, to diagnose and treat lesions affecting the human neurovascular system through methods such as selective angiography, interventional embolization, dilatation, mechanical removal, and drug delivery. Based on their functions and scope of application, neurointerventional medical devices can be divided into three categories: hemorrhagic stroke treatment, ischemic stroke treatment, and access devices. Hemorrhagic stroke treatment products are primarily used to treat intracranial aneurysms and occlude malformed vessels, while ischemic stroke treatment products are primarily used to treat acute ischemic stroke and cerebrovascular occlusive diseases (such as intracranial atherosclerosis). Currently, a variety of self-expanding stents have been developed for the treatment of neurovascular diseases, including blood flow-directed dense mesh stents, coil-assisted stents, intracranial thrombectomy stents, and intracranial stents.

[0003] In clinical applications, the visibility (also known as radiopacity) of tubular stents is crucial to ensure clinicians deploy the device in the correct location for medical purposes such as thrombus capture or vasodilation. Conventional stents are typically made of nickel-titanium alloy, and their radiopacity is insufficient to meet clinical application requirements. Therefore, to enhance visibility or other functionalities, tubular stents are often equipped with radiopaque or other functional features. However, the installation of such features often compromises the smoothness of the stent's outer surface. For example, the placement of radiopaque features on the stent body creates protrusions that are distinct from the struts of the stent body. This not only increases resistance during stent delivery, but also protrudes beyond the struts of the stent body when expanded, causing damage to the vessel wall. This is particularly true for tortuous vessels, where tubular stents are more susceptible to damage.

[0004] Therefore, how to safely arrange functional mechanisms on a tubular stent to ensure the realization of corresponding functions (such as imaging function) while reducing the damage of the tubular stent to the blood vessel wall is a technical problem that needs to be solved in this field. Summary of the Invention

[0005] In view of the shortcomings of the prior art, one of the objectives of the present invention is to provide a tubular stent, comprising:

[0006] A hollow cylindrical stent body having a hollow grid and a free end extending axially and integrally formed with the stent body; the free end is located between the proximal and distal ends of the stent body;

[0007] The stent auxiliary rod has a proximal end connected to the free end of the stent and a distal end extending into the interior of the stent body.

[0008] The tubular stent provided in the present application solves the problems existing in the prior art by setting a stent free end and setting a stent auxiliary rod at the distal end of the stent free end. Specifically, the stent auxiliary rod is set to be a stent auxiliary rod made of non-radiopaque material to provide a development function; the stent free end is connected to the stent auxiliary rod, and the stent auxiliary rod extends to the inside of the stent body, which can limit the stent free end from extending or stretching outside the stent body cavity wall, especially in a curved blood vessel, the stent auxiliary rod can better limit the stent free end from extending outside the tubular stent cavity, thereby avoiding damage to the blood vessel wall; on the other hand, under the joint action of the stent free end and the stent auxiliary rod, the connection position of the stent auxiliary rod and the stent free end has space to deviate toward the inner cavity of the tubular stent. When encountering extrusion, the connection position has space to deviate toward the inner cavity, and this offset space will reduce the damage of the tubular stent to the blood vessel wall and reduce the resistance when pushing in the delivery catheter.

[0009] Preferably, the length of the free end of the stent is shorter than the length from the proximal end of the free end of the stent to the distal end of the grid where the free end of the stent is located.

[0010] If the length of the free end of the stent is too long, such as exceeding the length of the far end of the grid in which it is located, it is easy for the connection position between the free end of the stent and the stent auxiliary rod to overlap with the support rod of the grid, which will increase the pushing resistance of the tubular stent in the delivery catheter.

[0011] Preferably, the length of the free end of the bracket is less than 1 / 2 of the length from the proximal end of the free end of the bracket to the distal end of the grid where it is located, and preferably the length of the free end of the bracket is less than 1 / 4 of the length from the proximal end of the free end of the bracket to the distal end of the grid where it is located.

[0012] The longer the free end of the tubular stent is, the shorter the stent auxiliary rod is, and the corresponding functionality (such as imaging) will be reduced.

[0013] In addition, the length of the free end of the stent is preferably greater than or equal to 1 / 10 of the length from the proximal end of the free end of the stent to the distal end of the grid where it is located.

[0014] The shorter the length of the free end of the stent, the smaller the radial deformation of the free end of the stent. After connecting the stent auxiliary rod, the deformation space of the connection position into the tubular stent cavity is smaller, and the connection position is more likely to protrude outside the inner cavity of the tubular stent.

[0015] Preferably, the distal ends of the auxiliary rods of the stent converge, and the convergence point is located on the central axis of the stent body.

[0016] The distal ends of the stent auxiliary rods converge, which can more effectively confine the free ends of the stent within the cavity of the tubular stent, especially the convergence point is located on the central axis of the stent body, which can better confine all axially distributed free ends of the stent.

[0017] Preferably, the included angles between the distal ends of the adjacent stent auxiliary rods are the same, and the included angles between the distal ends of the stent auxiliary rods and the central axis of the stent body are the same.

[0018] The identical angles at the distal ends of adjacent stent auxiliary rods can better ensure uniform circumferential distribution of the stent auxiliary rods, enabling better visualization of the tubular stent. Furthermore, the identical angles at the distal ends of adjacent stent auxiliary rods can ensure that the free ends of stents located in the same circumferential direction are interconnected via the stent auxiliary rods, better ensuring that the free ends of the stents do not extend outside the tubular stent cavity due to stent bending, and also preventing excessive deformation caused by varying stent retraction angles during stent retraction.

[0019] Preferably, the angle between the bracket auxiliary rod and the central axis is 30~80°, for example, 42°, 45°, 48°, 53°, 55°, 58°, 64°, 65°, 69°, 73°, 77°, 79°, etc.

[0020] The stent-assisting rod and the central axis have a certain angle, which can supplement the radial support force of the tubular stent without affecting the compliance of the tubular stent in tortuous blood vessels. If the angle is too small, the increase in radial support force is not significant. If the angle is too large, the support force on the lumen wall of the tubular stent is too large, which affects the smoothness of the retrieval of the tubular stent for thrombectomy stents. For intracranial stents, it is easy to cause irritation to the blood vessel wall, increasing the risk of complications. The angle between the stent-assisting rod and the central axis is the angle between the stent-assisting rod and the central axis extending proximally, with the distal end of the stent-assisting rod as the apex.

[0021] Preferably, the support auxiliary rod has a curved shape, and the curved shape enables the distal end of the support auxiliary rod to extend toward the central axis.

[0022] The stent auxiliary rod is configured to have a curved structure, which can improve the firmness of the distal end convergence of the stent auxiliary rod and enhance the supplementary radial support force of the tubular stent. The curvature of the stent auxiliary rod can be achieved by pre-forming.

[0023] As an optional specific embodiment, the support auxiliary rod includes a parallel section parallel to the central axis, and an inclined section with a distal end close to the central axis.

[0024] Preferably, the connection between the bracket auxiliary rod and the free end is a rigid connection or a flexible connection.

[0025] Further preferably, the connection method between the bracket auxiliary rod and the free end of the bracket includes any one of fixed sleeve connection, welding, bonding or clamping, or a combination of at least two of them.

[0026] As an optional specific embodiment, the stent auxiliary rods converging together at the distal end are defined as stent auxiliary units, and the number of the stent auxiliary units along the axial direction of the stent body is greater than or equal to 1, and the stent auxiliary units are arranged near the point where the distance between the proximal end and the distal end of the stent body is equally divided.

[0027] That is, the bracket auxiliary units described in this application are evenly distributed along the axial direction. This setting can provide better radial support to the tubular bracket body. When the bracket auxiliary rod has development performance, it can also better develop the tubular bracket in sections, better locate the position of the tubular bracket, and determine the direction of the tubular bracket.

[0028] Preferably, the distal end of the free end of the stent has a cross-section perpendicular to the axial direction with a circumferential length greater than a length perpendicular to the axial direction.

[0029] The distal cross-section of the free end of the stent in the present application is set to be flat, and the circumferential length of the cross-section along the tubular stent is greater than the radial length of the tubular stent. This setting is more conducive to connection with the stent auxiliary rod.

[0030] Preferably, the proximal end of the free end of the stent is located at the grid intersection of the hollow grid.

[0031] The hollow grid described in the present application is formed by connecting the pillars end to end, and more than three pillars in the middle of the bracket body converge at the grid intersection; the proximal end of the free end of the bracket is set at the grid intersection, and the grid intersection with the proximal end of the free end of the bracket is the free end intersection.

[0032] In a preferred embodiment, the free end intersection only brings together three of the struts.

[0033] Preferably, the distal ends of the stent auxiliary rods converge, and a radiopaque mechanism is provided at the convergence point, preferably a radiopaque ring or a radiopaque coil.

[0034] Preferably, a radiopaque device is provided at the distal end of the stent body.

[0035] A second object of the present application is to provide a bracket system, characterized in that the bracket system comprises:

[0036] The tubular stent according to one of the purposes;

[0037] a push wire connected to the proximal end of the tubular stent;

[0038] A catheter is used for delivering the tubular stent.

[0039] Compared with the prior art, this application has the following beneficial effects:

[0040] The tubular stent provided in the present application provides a functional mechanism for the tubular stent by setting a free end of the stent and setting a stent auxiliary rod at the distal end of the free end of the stent. At the same time, by setting the free end and the stent auxiliary rod, the connection between the free end of the stent and the stent auxiliary rod has space to deform into the tubular stent cavity, and the delivery resistance will not be increased due to the setting of the functional mechanism, nor will the risk of damage to the blood vessel be increased due to the setting of the functional mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the flattening and unfolding of the tubular stent provided in Example 1;

[0042] Figure 2 A schematic diagram of the three-dimensional structure of the tubular stent provided in Example 1;

[0043] Figure 3 for Figure 1 The enlarged structural diagram in the dotted box;

[0044] Figure 4 A schematic diagram of the three-dimensional structure of the stent auxiliary rod 200 of the tubular stent provided in Example 1;

[0045] Figure 5 A schematic diagram of the right side structure of the stent auxiliary rod 200 of the tubular stent provided in Example 1;

[0046] Figure 6 A schematic diagram of the cross-sectional structure of the free end of the tubular stent at the connection point provided in Example 1;

[0047] Figure 7 This is a schematic diagram of the flattening and unfolding of the tubular stent provided in Example 2;

[0048] Figure 8 This is a schematic diagram of the flattening and unfolding of the tubular stent provided in Example 3;

[0049] Figure 9 A schematic structural diagram of the stent auxiliary unit 200 of the tubular stent provided in Example 3 from a distal perspective;

[0050] Figure 10 This is a schematic structural diagram of the tubular support provided in Example 4. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further explained below in conjunction with specific implementation methods. However, it should be noted that the specific implementation methods are only a specific implementation and explanation of the essence of the technical solution of the present invention and should not be understood as a limitation on the scope of protection of the present invention.

[0052] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the relevant invention are shown in the accompanying drawings.

[0053] In the description of this application, it should be understood that the terms "distal" and "proximal" should be understood as viewed from the direction of the operator: the "distal" end is the end away from the operator, while the "proximal" end is the end closer to the operator. The term "axial" should be understood as the direction of stent delivery, the length of the guidewire, or the length of the stent, and the term "radial" should be understood as the direction perpendicular to the "axial" end.

[0054] In the description of this application, it should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0055] Example 1

[0056] like Figures 1 to 4 ( Figure 1 This is a schematic diagram of the flattening and unfolding of the tubular stent provided in Example 1. Figure 2 This is a schematic diagram of the three-dimensional structure of the tubular stent provided in Example 1. Figure 3 for Figure 1 The enlarged structural diagram in the dotted box, Figure 4 This is a schematic diagram of the three-dimensional structure of the stent auxiliary rod 200 of the tubular stent provided in Example 1. Figure 5 This is a schematic diagram of the right side structure of the stent auxiliary rod 200 of the tubular stent provided in Example 1. Figure 6 As shown in the schematic diagram of the cross-sectional structure of the free end of the tubular stent at the connection of the tubular stent provided in Example 1, Example 1 provides a tubular stent comprising:

[0057] The hollow cylindrical stent body 100 is divided into a proximal portion (10), a middle portion 20 and a distal portion (30) along the axial direction. The stent body has a hollow grid, and the hollow grid has a plurality of arranged hollow structures 110. Each hollow structure is surrounded by at least 4 (such as 4, 5, 6) pillars 111 connected end to end. The ends of the pillars 111 intersect at an intersection. In the middle portion 20 of the stent body, a stent free end 120 is selectively set at the intersection; the stent self-supporting structure is provided. The intersection of the ends 120 is a second intersection 113, and the intersection without a bracket free end 120 is a first intersection 112. The second intersection 113 intersects only three pillars 111. A third intersection 114 is located within the same hollow structure 110 as the second intersection 113. This third intersection 114 intersects only three pillars 111, and two intersections are separated from the third intersection 114 and the second intersection 113. The bracket free end 120 is integrally carved with the bracket body (i.e., a one-piece design). A group of bracket free end assemblies is provided in the middle portion 20 of the bracket body 100, and the bracket free end assemblies include three bracket free ends 120.

[0058] The length of the free end 120 of the bracket is A, and the distance between the free end 120 of the bracket and the farthest intersection of the hollow structure 110 is B. A and B satisfy that A is less than or equal to 1 / 2B, preferably less than or equal to 1 / 4B; preferably, A and B also satisfy that A is greater than or equal to 1 / 10B.

[0059] The tubular stent also includes a stent-assisting unit 200, which is equipped with three stent-assisting rods 210. The proximal ends of the three stent-assisting rods 210 are respectively connected to the three stent free ends 120 in the stent free end set. The distal ends of the three stent-assisting rods 210 intersect at a convergence point 220, which is located at the central axis 300 of the tubular stent body. The stent-assisting rods 210 include a proximal parallel section 211 and a distal inclined section 212. The larger the angle between the proximal parallel section 211 and the distal inclined section 212, the smaller the angle α between the distal end of the stent-assisting rod 210 (i.e., the inclined section 212) and the central axis 300 of the stent body. In Example 1, the angle α is 66°. The distal ends of the three stent-assisting rods 210 in the stent-assisting unit 200 all have the same angle with the central axis 300 of the stent body.

[0060] Only one stent auxiliary unit 200 is set along the length direction of the tubular stent, and the proximal ends of the three stent free ends 120 connected to the three stent auxiliary rods 210 of the stent auxiliary unit 200 can be located in the same circumferential direction or different circumferential directions. The proximal ends of the stent auxiliary rods 210 of the same stent auxiliary unit 200 can be located in the same circumferential direction or different circumferential directions, and the intersection of the proximal parallel section 211 and the distal inclined section 212 of the stent auxiliary rods of the same stent auxiliary unit 200 is located in the same circumferential direction.

[0061] The distal ends of two adjacent stent-assisting rods 210 of the three stent-assisting rods 210 in the stent-assisting unit 200 have the same included angle. In Example 1, the included angles β1, β2, and β3 of the distal ends of the stent-assisting rods 210 projected on a cross-section perpendicular to the central axis 300 of the tubular stent body are all approximately 120°.

[0062] In other embodiments, the angle α between the distal end of the stent auxiliary rod and the central axis 300 of the stent body can also be 43°, 50°, 55°, etc.

[0063] The connection method of the connection point 130 between the proximal end of the stent auxiliary rod 210 and the free end 120 of the stent is a rigid fixed connection. For example, the proximal end of the stent auxiliary rod 210 is fixed to the distal end of the free end 120 of the stent by sleeve-mounting a fixed metal ring 131 and then filling it with an adhesive material 132.

[0064] In a preferred technical solution, the cross-section of the distal end of the stent auxiliary rod 210 is rectangular, and its circumferential length L1 is greater than its length L2 perpendicular to the axial direction.

[0065] In other embodiments, the connection method of the connection point 130 between the proximal end of the stent auxiliary rod 210 and the stent free end 120 can also be welding, clamping or direct bonding.

[0066] The stent-assisting unit 200 is made entirely of radiopaque material. In other embodiments, the stent-assisting rod 210 or the convergence point 220 of the stent-assisting unit 200 may be made entirely, partially, or not at all of radiopaque material. Preferably, at least one of the stent-assisting rods 210 or convergence point 220 is made of radiopaque material. In other embodiments, the radiopaque material may be attached to the stent-assisting unit, such as by a C-ring clamp or wrapping.

[0067] It should be noted that the angles and the same angles described in this application are the same as long as the processing accuracy allows, that is, the errors caused by the processing accuracy are allowed.

[0068] Example 2

[0069] like Figure 7 ( Figure 7 Schematic diagram of a tubular stent provided in Example 2 is shown. Example 2 provides a tubular stent, comprising:

[0070] The hollow cylindrical stent body 100 is divided into a proximal portion ( Figure 7 Not shown), the middle portion 20 and the distal portion ( Figure 7 (Not shown) The stent body has a hollow grid with multiple arranged hollow structures 110. Each hollow structure is formed by at least four (e.g., four, five, or six) pillars 111 connected end to end. The ends of the pillars 111 intersect at an intersection. In the middle portion 20 of the stent body, the intersections are intersected by the ends of four pillars 111. Stent free ends 120 are optionally provided at these intersections. Intersections with stent free ends 120 are referred to as fourth intersections 115, while intersections without stent free ends 120 are referred to as first intersections 112. The stent free ends 120 are integrally carved with the stent body (i.e., an integral design). At least three stent free ends 120 are provided in the middle portion 20 of the stent body 100.

[0071] The tubular stent further includes a stent auxiliary unit 200 , and the configuration of the stent auxiliary unit 200 is the same as that of the first embodiment.

[0072] Example 3

[0073] like Figures 8 and 9 ( Figure 8 This is a schematic diagram of the flattening and unfolding of the tubular stent provided in Example 3. Figure 9 As shown in the structural schematic diagram of the stent auxiliary unit 200 of the tubular stent provided in Example 3 from a distal perspective, Example 3 provides a tubular stent, comprising:

[0074] The hollow cylindrical stent body 100 is divided into a proximal portion ( Figure 8 Not shown), the middle portion 20 and the distal portion ( Figure 8 (Not shown) The stent body comprises a hollow grid with a plurality of arranged hollow structures 110. Each hollow structure is formed by at least four (e.g., four, five, or six) struts 111 connected end to end. Free ends 120 are provided on at least a portion of each strut 111. These free ends 120 are integrally carved with the stent body (i.e., a one-piece design). At least four free ends 120 are provided in the middle portion 20 of the stent body 100.

[0075] The tubular stent also includes a stent auxiliary unit 200, which is provided with four stent auxiliary rods 210, and the proximal ends of the four stent auxiliary rods 210 are respectively connected to the four stent free ends 120, and the distal ends of the four stent auxiliary rods 210 intersect at a convergence point 220, and the convergence point 220 is located at the central axis 300 of the tubular stent body. The stent auxiliary rod 210 includes a proximal parallel section 211 and a distal inclined section 212. In Example 3, the angle α between the distal end of the stent auxiliary rod 210 and the central axis 300 of the stent body is 50°. The angles between the distal ends of the four stent auxiliary rods 210 in the stent auxiliary unit 200 and the central axis 300 of the stent body are all the same.

[0076] Along the length direction of the tubular stent, only one stent auxiliary unit 200 is set, and the proximal ends of the four stent free ends 120 connected to the four stent auxiliary rods 210 of the stent auxiliary unit 200 can be located in the same circumferential direction or different circumferential directions. The proximal ends of the stent auxiliary rods 210 of the same stent auxiliary unit 200 can be located in the same circumferential direction or different circumferential directions, and the intersection of the proximal parallel section 211 and the distal inclined section 212 of the stent auxiliary rods of the same stent auxiliary unit 200 is located in the same circumferential direction.

[0077] The distal ends of two adjacent stent auxiliary rods 210 of the four stent auxiliary rods 210 in the stent auxiliary unit 200 have the same angle. In Example 3, the distal ends of the stent auxiliary rods 210 are projected at an angle of about 90° in a cross-section perpendicular to the central axis 300 of the tubular stent body.

[0078] In other specific embodiments, the number of stent auxiliary rods 210 in a stent auxiliary unit 200 is n, n≥2, n is an integer, which can be 3, 4, 5, 6, 7, 8, etc. The angles between the distal ends of the n stent auxiliary rods 210 in the stent auxiliary unit 200 and the central axis 300 of the stent main body are all the same, and the angles of the projections of the distal ends of the stent auxiliary rods 210 on the cross section perpendicular to the central axis 300 of the tubular stent main body are all about 360° / n.

[0079] Example 4

[0080] like Figure 10 ( Figure 10 As shown in the structural schematic diagram of the tubular bracket provided in Example 4, Example 4 provides a tubular bracket having a hollow cylindrical main body 100 with the same structure as Example 1, except that the middle part 20 of the bracket main body 100 is provided with two groups of bracket free end sets, a first bracket free end set 141 and a second bracket free end set 142, and each of the bracket free end sets is independently provided with three bracket free ends 120.

[0081] The tubular bracket also includes two bracket auxiliary units, a first bracket auxiliary unit 201 and a second bracket auxiliary unit 202. The structure of each bracket auxiliary unit is the same as that in Example 1. The only difference is that the connection method between the first bracket auxiliary unit 201 and the second bracket auxiliary unit 202 and the bracket body has been adaptively adjusted. Specifically, the first bracket free end set 141 is connected to the first bracket auxiliary unit 201, and the second bracket free end set 142 is connected to the second bracket auxiliary unit 202. The specific connection method is the same as that in Example 1.

[0082] In Example 4, the first stent auxiliary unit 201 and the second stent auxiliary unit 202 are arranged along the axial direction of the stent body near the points dividing 1 / 3 and 2 / 3 of the distance between the proximal end and the distal end of the stent body.

[0083] It should be noted that Figure 10 Only two support auxiliary rods 210 can be seen in the middle support auxiliary unit. This is because Figure 10 The problem of viewing angle is that the support auxiliary rod 210 is blocked and cannot be shown from the view.

[0084] The specific embodiment of the present application further provides a support system, including:

[0085] The tubular stent as described in any one of the preceding embodiments 1 to 3;

[0086] a push wire fixedly connected to the proximal end of the tubular stent;

[0087] and a catheter for delivering the tubular stent.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. 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 tubular stent, characterized in that: The tubular support comprises: A hollow cylindrical stent body having a hollow grid and a free end extending axially and integrally formed with the stent body; the free end is located between the proximal and distal ends of the stent body; a stent auxiliary rod, the proximal end of which is connected to the free end of the stent and the distal end of which extends into the interior of the stent body; The stent auxiliary rod is configured as a stent auxiliary rod made of radiopaque material; The distal ends of the auxiliary rods of the support converge, and the convergence point is located on the central axis of the support body.

2. The tubular stent according to claim 1, wherein: The length of the free end of the bracket is shorter than the length from the proximal end of the free end of the bracket to the distal end of the grid where the free end of the bracket is located.

3. The tubular stent according to claim 1, wherein: The length of the free end of the bracket is less than 1 / 4 of the length from the proximal end of the free end of the bracket to the distal end of the grid where the free end of the bracket is located.

4. The tubular stent according to claim 1, wherein: The included angles of the distal ends of the adjacent support auxiliary rods are the same, and the included angles of the distal ends of the support auxiliary rods and the central axis of the support body are the same.

5. The tubular stent according to claim 1, wherein: The angle between the distal end of the bracket auxiliary rod and the central axis of the bracket body is 30-80 degrees.

6. The tubular stent according to claim 1, wherein: The support auxiliary rod has a curved shape, and the curved shape makes the distal end of the support auxiliary rod extend toward the central axis.

7. The tubular stent according to claim 6, wherein: The support auxiliary rod includes a parallel section parallel to the central axis and an inclined section with a distal end close to the central axis.

8. The tubular stent according to claim 1, wherein: The connection between the bracket auxiliary rod and the free end of the bracket is a rigid connection or a flexible connection.

9. The tubular stent according to claim 1, wherein: The connection method between the bracket auxiliary rod and the free end of the bracket includes any one of fixed sleeve connection, welding, bonding or clamping, or a combination of at least two of them.

10. The tubular stent according to claim 1, wherein: The stent auxiliary rods converging together at the distal end are defined as stent auxiliary units. Along the axial direction of the stent body, the number of the stent auxiliary units is greater than or equal to 1, and the stent auxiliary units are arranged near the equal-division point of the distance between the proximal end and the distal end of the stent body.

11. The tubular stent according to claim 1, wherein: The distal end of the free end of the stent has a cross section perpendicular to the axial direction, and a circumferential length thereof is greater than a length thereof perpendicular to the axial direction.

12. The tubular stent according to claim 1, wherein: The proximal end of the free end of the bracket is located at the grid intersection of the hollow grid.

13. The tubular stent according to claim 1, wherein: The distal ends of the stent auxiliary rods converge, and a radiopaque mechanism is provided at the convergence point.

14. The tubular stent according to claim 13, wherein: A radiopaque ring or a radiopaque coil is provided at the convergence point.

15. The tubular stent according to claim 1, wherein: A radiopaque device is provided at the distal end of the stent body.

16. A support system, characterized in that: The support system comprises: The tubular stent according to any one of claims 1 to 15; a push wire connected to the proximal end of the tubular stent; A catheter is used for delivering the tubular stent.

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