Bare stent sub-unit and bare stent

Abstract

The invention discloses a bare stent sub-unit and a bare stent, and belongs to the technical field of medical instruments.The bare stent sub-unit comprises wave crests, wave troughs, oblique beams and closed-loop structures, the wave crests and the wave troughs are arranged at intervals, one end of each oblique beam is used for being connected to the corresponding wave crest, and the other end of each oblique beam is used for being connected to the corresponding wave trough; the wave crests, the wave troughs and / or the oblique beams extend in the circumferential direction to form at least one ring. The closed-loop structure is arranged on at least one of the wave crest, the wave trough and the oblique beam. According to the bare stent, the closed-loop structures are arranged on the wave crests, the wave troughs and / or the oblique beams, when the bare stent sub-units are combined into the bare stent, the flexible connecting pieces can be connected to the closed-loop structures to connect different bare stent sub-units, the connecting stability between the bare stent sub-units can be improved, the overall shape and size precision of the bare stent can be guaranteed, and the bare stent is convenient to assemble and disassemble. The bare stent is prevented from being in an abnormal stress state to influence the fatigue performance, and structural damage to the bare stent is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a bare stent subunit and a bare stent. Background Art

[0002] As an important part of the blood circulation system, the human aorta has a complex and delicate three-layer structure, namely the intima, the media and the adventitia. This structural characteristic plays a vital role in maintaining the normal physiological function of the aorta. However, when a rupture occurs in the intima of the aortic wall, blood may enter the aortic media from the rupture and expand along the long axis of the aorta under the drive of pulse pressure, forming aortic dissection (AD). Aortic dissection is an extremely dangerous cardiovascular disease with an acute onset, rapid progression, and extremely high mortality, posing a serious threat to human health.

[0003] Aortic dissection is divided into type A and type B according to its pathological characteristics and treatment needs. For type A aortic dissection, surgical treatment is currently the main treatment method to completely repair the damaged aortic wall. For type B aortic dissection, endovascular treatment is widely recommended due to its advantages such as less trauma and faster recovery. The core of endovascular treatment is to accurately implant the covered stent into the blood vessel through a delivery device to block the proximal rupture of the dissection, thereby restoring normal blood flow in the aorta.

[0004] However, in the actual treatment process, if the dissection involves too long a part or involves distal branch vessels, it is often difficult to effectively treat the distal end. This is because the implantation length of the covered stent is limited. If it is too long, it may affect the blood supply of the intercostal artery, thereby increasing the risk of postoperative paraplegia. In order to improve the distal blood supply, some technical solutions attempt to expand the true lumen by implanting a bare stent distally. Although the distal rupture may continue to receive blood perfusion, this method will not block the blood supply of the distal intercostal artery and branch vessels. The use of bare stents has alleviated the problem of distal blood supply to a certain extent.

[0005] However, in the known technology, during the delivery process or after implantation of the bare stent, the fixed position of the connector and the bare stent subunit is prone to slip. This slip not only affects the overall shape and dimensional accuracy of the bare stent, but also puts it in an abnormal stress state, thereby reducing the fatigue performance of the stent. In the long run, the stent is prone to structural damage, leading to treatment failure or even more serious complications.

[0006] Therefore, how to ensure that the bare stent effectively expands the true lumen while solving the problem of its connection stability has become a technical challenge that needs to be urgently solved in the field of endovascular treatment of aortic dissection. Summary of the invention

[0007] The purpose of the present invention is to provide a bare bracket sub-unit and a bare bracket to solve the problems existing in the above-mentioned prior art. By arranging a closed-loop structure on the crests, troughs and / or inclined beams, when the bare bracket sub-units are combined into a bare bracket, different bare bracket sub-units can be connected to the closed-loop structure by using flexible connectors, which can improve the connection stability between the bare bracket sub-units, ensure the overall shape and dimensional accuracy of the bare bracket, avoid putting the bare bracket in an abnormal stress state and affecting its fatigue performance, and avoid structural damage to the bare bracket.

[0008] To achieve the above object, the present invention provides the following solutions: The present invention provides a bare bracket subunit, comprising wave crests and wave troughs arranged at intervals, an inclined beam and a closed-loop structure, wherein one end of the inclined beam is used to be connected to the wave crest, and the other end of the inclined beam is used to be connected to the wave trough, and the wave crests, the wave troughs and / or the inclined beams extend in a circumferential direction to form at least one ring; the closed-loop structure is arranged on at least one of the wave crests, the wave troughs and the inclined beams.

[0009] In one embodiment, the wave crests, the oblique beams and the wave troughs are repeatedly arranged to form an annular structure connected end to end.

[0010] In one embodiment, the ends of the annular structure are connected by sleeve riveting, welding or micro-spring winding.

[0011] In one embodiment, the wave crests, the oblique beams and the wave troughs are repeatedly arranged to form an open-loop structure that is disconnected at the beginning and the end.

[0012] In one embodiment, the open-loop structure is a spiral structure.

[0013] In one embodiment, the closed-loop structure is a full-circle closed loop or a spiral closed loop, and the spiral closed loop includes a single-layer or multi-layer spiral.

[0014] In one embodiment, the closed-loop structures are staggered with respect to each other in the axial direction of the bare stent subunits.

[0015] The present invention also provides a bare stent, comprising one or more bare stent sub-units as described above and a flexible connector, wherein the bare stent sub-units are arranged axially; and the flexible connector is connected to the closed-loop structure of different bare stent sub-units.

[0016] In one embodiment, the flexible connector connects the closed-loop structure of different bare stent sub-units axially and / or circumferentially.

[0017] In one embodiment, the flexible connector includes stretchable structures nested with each other and / or the flexible connector is elastic.

[0018] Compared with the prior art, the present invention has achieved the following technical effects: In addition to being provided with crests, troughs and inclined beams, the bare support subunits of the present invention are also provided with a closed-loop structure. By arranging the closed-loop structure on the crests, troughs and / or inclined beams, when the bare support subunits are combined into a bare support, different bare support subunits can be connected to the closed-loop structure by using flexible connectors. Due to the constraints of the closed-loop structure, the connection position of the flexible connector is relatively fixed, which can improve the connection stability between the bare support subunits, ensure the overall shape and dimensional accuracy of the bare support, avoid putting the bare support in an abnormal stress state and affecting its fatigue performance, and avoid structural damage to the bare support. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 Schematic diagram of bare stent subunits in a ring-shaped structure connected end to end in an embodiment of the present invention; Figure 2 This is a schematic diagram of the use of sleeve connection when connecting the ends in an embodiment of the present invention; Figure 3 Schematic diagram of a bare stent subunit with an open-loop structure that is disconnected at both ends in an embodiment of the present invention; Figure 4 It is a schematic diagram of the spiral structure of the bare stent subunit in the embodiment of the present invention; Figure 5 Schematic diagram of a closed loop structure in a full circular closed loop according to an embodiment of the present invention; Figure 6 Schematic diagram of a closed loop structure in a spiral closed loop in an embodiment of the present invention; Figure 7 This is a schematic diagram before bending when the closed-loop structure of the inclined beam in the embodiment of the present invention is a spiral closed loop wound with metal wire; Figure 8 This is a schematic diagram of a closed-loop structure of the inclined beam in an embodiment of the present invention, when the closed-loop structure is a spiral closed-loop structure of a metal wire, after bending; Fig. 9 A schematic diagram of a closed-loop structure in which the peaks and valleys are in an embodiment of the present invention; Fig.10 This is a schematic diagram of another form of a closed-loop structure in which the wave crests and troughs are in an embodiment of the present invention; Fig.11It is a schematic diagram of a bare stent in which a flexible connector is circumferentially connected to bare stent subunits in a ring-shaped structure in an embodiment of the present invention; Fig.12 for Fig.11 Schematic diagram from another angle; Fig.13 This is a schematic diagram of a flexible connector interlaced and wound around a closed loop structure in an embodiment of the present invention; Fig.14 It is a schematic diagram of a bare stent (the first and second ends are in a free state) before bending in which the bare stent subunits having an open-loop structure are axially connected by a flexible connector in an embodiment of the present invention; Fig.15 for Fig.14 Schematic diagram from another angle; Fig.16 It is a schematic diagram of a bare stent (the head and tail ends are connected to the inclined beam) before bending in which the flexible connector axially connects the bare stent sub-units in an open-loop structure in an embodiment of the present invention; Fig.17 for Fig.16 Schematic diagram from another angle; Fig.18 It is a schematic diagram of a bare stent (the head and tail ends are connected to the inclined beam) after bending, in which the flexible connector is axially connected to the bare stent sub-units in an open-loop structure in an embodiment of the present invention; Fig.19 A schematic diagram of a structural form of a flexible connector in an embodiment of the present invention; Fig. 20 for Fig.19 Schematic diagram of the flexible connector on one side; Fig.21 Schematic diagram of another structural form of a flexible connector in an embodiment of the present invention; Fig. 22 for Fig.21 Only one side of the connecting rope is provided with an anti-drop structure schematic diagram; Among them, 1. crest; 2. trough; 3. inclined beam; 4. closed loop structure; 5. flexible connector; 6. casing; 41. Full circle closed loop; 42. Spiral closed loop; 51. First connecting rope; 511. First knot; 512. First anti-slip structure; 52. Second connecting rope; 521. Second knot; 522. Second anti-slip structure. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The purpose of the present invention is to provide a bare bracket sub-unit and a bare bracket to solve the problems existing in the prior art. By arranging a closed-loop structure on the crests, troughs and / or inclined beams, when the bare bracket sub-units are combined into a bare bracket, different bare bracket sub-units can be connected to the closed-loop structure using flexible connectors, which can improve the connection stability between the bare bracket sub-units, ensure the overall shape and dimensional accuracy of the bare bracket, avoid putting the bare bracket in an abnormal stress state and affecting its fatigue performance, and avoid structural damage to the bare bracket.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 to Figure 22 As shown, the present invention provides a bare stent subunit, including a crest 1 and a trough 2 arranged at intervals, an inclined beam 3 and a closed-loop structure 4, one end of the inclined beam 3 is used to connect to the crest 1, and the other end of the inclined beam 3 is used to connect to the trough 2, thereby, the crest 1, the trough 2 and the inclined beam 3 are combined into a wave structure, and a single bare stent subunit can include one or more complete wave structures, and can also include a partially incomplete wave structure, for example, lacking half or the entire crest 1 (or trough 2 or inclined beam 3), one of the wave structures has only half of the wave, etc. In addition, it should be noted that: crest 1 and trough 2 are only defined in name, and the two can adopt the same or different structures. If the orientation of the bare stent subunit is reversed, the crest 1 may be at the position of the trough 2, and the trough 2 may be at the position of the crest 1. The crest 1, the trough 2 and / or the inclined beam 3 extend in the circumferential direction to form at least one ring, and the annular bare stent subunit can be used to form a bare stent after one or more combinations to achieve annular support in the blood vessel. The location of the closed loop structure 4 is not specifically restricted. The closed loop structure 4 can be arranged on one of the crest 1, the trough 2 and the inclined beam 3, or on any two of them, or on all three. The closed loop structure 4 can be formed by bending the crest 1, the trough 2 or the inclined beam 3 itself, or can be a structure connected by welding, bonding, etc.

[0025] In addition to the crests 1, troughs 2 and inclined beams 3, the bare support subunits of the present invention are also provided with a closed-loop structure 4. By arranging the closed-loop structure 4 on the crests 1, troughs 2 and / or inclined beams 3, when the bare support subunits are combined into a bare support, different bare support subunits can be connected to the closed-loop structure 4 using a flexible connector 5. Due to the constraints of the closed-loop structure 4, the connection position of the flexible connector 5 is relatively fixed, which can improve the connection stability between the bare support subunits, ensure the overall shape and dimensional accuracy of the bare support, avoid putting the bare support in an abnormal stress state and affecting its fatigue performance, and avoid structural damage to the bare support.

[0026] In one embodiment, if Figure 1 As shown, the crest 1, the oblique beam 3 and the trough 2 are repeatedly arranged to form an annular structure connected end to end. The waveform structure (including one crest 1, one trough 2 and four oblique beams 3) composed of the crest 1, the trough 2 and the oblique beam 3 contained in the annular structure can be an integer waveform structure or a non-integer waveform structure. Usually, the waveform structure can be made first and then connected end to end. The closed-loop structure 4 can be arranged only on the same side of the axial direction of the annular structure, or on both sides of the axial direction of the annular structure. When the closed-loop structure 4 is arranged, it is in the same annular surface as the annular structure. The closed-loop structure 4 itself can also have a certain curvature to minimize the radial space occupied by the closed-loop structure 4. At the same time, it can also prevent the subsequent surgery from easily entering the closed-loop structure 4 when pushing the guide wire, catheter or conveyor, causing serious medical accidents such as displacement of the bare stent, failure of instrument pushing, and even inability to release.

[0027] In one embodiment, when the bare stent subunits are connected to form a ring structure, the ends of the ring structure are connected by riveting, welding, or micro-spring winding of the sleeve 6. Figure 2 The structure using the riveting of the sleeve 6 is shown. Of course, the sleeve 6 can also be removed and welding can be performed directly (for example, laser welding). Alternatively, two wire heads (head end and tail end) are butt-jointed or overlapped and then riveted or welded with the sleeve 6 made of metal material, so that the bare bracket subunit forms a ring structure and is firmly connected. Generally, the wire head (head end or tail end) can be riveted or welded to the inclined beam 3 adjacent to the wire head with the sleeve 6.

[0028] In one embodiment, if Figure 3As shown, the crest 1, the oblique beam 3 and the trough 2 are repeatedly arranged to form an open-loop structure that is disconnected at the beginning and the end. The wave structure composed of the crest 1, the trough 2 and the oblique beam 3 contained in the open-loop structure can be an integer or a non-integer. The closed-loop structure 4 can be arranged only on the same side of the axial direction of the open-loop structure, or on both sides of the axial direction of the open-loop structure. When the closed-loop structure 4 is arranged, it is in the same annular surface as the open-loop structure. The closed-loop structure 4 itself can also have a certain curvature to minimize the radial space occupied by the closed-loop structure 4. At the same time, it can also prevent subsequent surgery from easily entering the closed-loop structure 4 when pushing the guide wire, catheter or conveyor, causing serious medical accidents such as displacement of the bare stent, failure of instrument pushing, and even inability to be released.

[0029] In one embodiment, the open-loop structure is a spiral structure, that is, one or more wavy structures forming the open-loop structure extend in the spiral direction, and finally form a bare bracket subunit with a single-turn or multi-turn spiral structure. For the bare bracket subunit with a multi-turn spiral structure or the bare bracket formed thereof, after heat treatment and shaping, due to the presence of the wave crest 1 (or the wave trough 2), the sleeve 6 may not be able to reach the inclined beam 3 adjacent to the wire head (head end or tail end), and thus the wire head cannot be connected to the inclined beam 3. In the winding process of the present invention, the sleeve 6 is reserved at the position of the inclined beam 3 adjacent to the wire head, and after heat treatment and shaping, the wire head is inserted into the reserved sleeve 6 for riveting to solve or avoid the above-mentioned problem of being unable to connect the wire head to the inclined beam 3.

[0030] In one embodiment, if Figure 5 As shown, the closed loop structure 4 is a full-circle closed loop 41, which can be formed by metal laser engraving. Figure 6 As shown, the closed-loop structure 4 is a spiral closed loop 42. At this time, it can be formed by winding a metal wire. The wound spiral closed loop 42 can include a single-layer or multi-layer spiral. The multi-layer spiral can further improve the flexibility of the bare stent subunit.

[0031] In one embodiment, in the bare bracket subunit, the closed loop structure 4 of the inclined beam 3 is a spiral closed loop 42 wound with metal wire. At this time, the inclined beam 3 has a certain axial bending ability. Figure 7 As shown, after bending Figure 8 As shown, by setting the spiral closed loop 42, the minimum bending unit of the bare stent formed by the bare stent sub-unit is reduced from the ring height (the height of the peak 1-the trough 2) of the bare stent sub-unit to the height of the closed loop structure 4 of the peak 1 (or the trough 2)-the oblique beam 3, thereby improving the overall flexibility of the bare stent.

[0032] In one embodiment, if Figure 1 , Figure 3 and Figure 4As shown, the crest 1 and the trough 2 can be open loops with a certain bending angle and bending radius. The bending radius range is generally: 0.3mm~3mm, so that the bare stent subunit has radial contraction and expansion functions while having a certain appropriate radial supporting force.

[0033] In one embodiment, in the bare stent subunit, the closed loop structure 4 of the crest 1 (or trough 2) is a spiral closed loop 42 wound with a metal wire. Fig. 9 The closed loop structure 4 shown is located outside the intersection of the inclined beam 3, and can also be formed as follows Fig.10 The closed loop structure 4 shown is a structural form located inside the intersection of the inclined beam 3. By adjusting the bending radius, number of spiral turns, spiral angle, spiral position (inside, outside) and other parameters of the spiral closed loop 42, the radial support force of the bare stent can be adjusted. At the same time, the spiral closed loop 42 at the crest 1 (or trough 2) position can reduce the stress of the bare stent when it is loaded into the conveyor for radial compression, avoiding plastic deformation.

[0034] In one embodiment, a plurality of closed-loop structures 4 are provided on the bare stent sub-unit, and the closed-loop structures 4 are staggered with each other in the axial direction of the bare stent sub-unit, which can reduce the compression diameter of the bare stent formed by the bare stent sub-unit when it is compressed into the delivery sheath, thereby facilitating delivery to the target vascular lesion site.

[0035] like Figure 11~Figure 21 As shown, the present invention also provides a bare stent, comprising one or more bare stent subunits as described above and a flexible connector 5, wherein the bare stent subunits are arranged axially, and adjacent bare stent subunits are connected by the flexible connector 5, and the flexible connector 5 can be made of sutures, metal wires or metal cables, etc., wherein the sutures can be polyester sutures or sutures woven with ultra-high molecular weight polyethylene fibers, etc. The bare stent subunits can be made of Figure 1 The ring structure shown or Figure 3 As for the open-loop structure shown (in this case, the whole bare stent is a continuous spiral shape), for the former, the axial support capacity is weak and radial misalignment may occur. The bare stent sub-units can be connected by adding straight or S-shaped longitudinal ribs and using the longitudinal ribs to connect adjacent bare stent sub-units, thereby improving the support capacity; for the latter, the bare stent sub-units are supported not only by the flexible connector 5, but also by the bare stent sub-units themselves, and have good support stability in both axial and radial directions. When connected, the flexible connector 5 is connected to the closed-loop structure 4 of different bare stent sub-units, and the closed-loop structure 4 is used to constrain or limit the position of the flexible connector 5 to ensure the stability of the connection structure and avoid changes in the overall shape and dimensional accuracy of the bare stent caused by the displacement of the flexible connector 5.

[0036] In one embodiment, the flexible connector 5 passes through or is tied to the closed loop structure 4 of the oblique beam 3 of the bare bracket subunit, and is connected to the crest 1 (or trough 2) of the adjacent bare bracket subunit, or is connected to the closed loop structure 4 of the adjacent bare bracket subunit, or is connected to both. Since the flexible connector 5 passes through or is tied to the closed loop structure 4, the flexible connector 5 will not slide on the smooth surface of the bare bracket subunit under stress, thereby preventing the bare bracket from being in an abnormal stress state such as abnormal stacking, folding, etc., and preventing fatigue fracture of the bare bracket.

[0037] In one embodiment, if Fig.11 and Fig.12 As shown, the flexible connector 5 circumferentially connects the closed loop structure 4 of different bare stent subunits. Figure 14~Figure 18 As shown, the flexible connector 5 axially connects the closed-loop structure 4 of different bare stent subunits. Of course, in the same bare stent, the flexible connector 5 can be set in the circumferential direction and the axial direction at the same time. Whether the flexible connector 5 is set in the axial direction or the circumferential direction, the connection stability between the bare stent subunits can be enhanced. When the flexible connector 5 is set in the axial direction, the flexible connector 5 can have a certain elongation ability, or the flexible connector 5 has a certain elasticity, so that when the bare stent adapts to the tortuous morphology of the blood vessel, the flexible connector 5 on the large bend side can be axially stretched, so that the distance between the bare stent subunits on the large bend side becomes larger, further improving its flexibility, reducing the straightening force of the bare stent, avoiding stimulation of the proximal and distal vascular walls of the stent due to the poor flexibility and high straightening force of the bare stent, and preventing new stent-induced ruptures.

[0038] The method of connecting the closed-loop structure 4 axially (longitudinally) by the flexible connector 5 has the following advantages: 1) After the bare stent is implanted in the body, the flexible connector 5 can better fit the blood vessel wall, solving the problem that the flexible connector 5 does not adhere to the wall after radial compression when the flexible connector 5 is circumferentially (transversely) connected to the bare stent, and can avoid the subsequent guide wire, catheter, etc. entering the flexible connector 5 that does not adhere to the wall and causing medical accidents. 2) The axial expansion and contraction of the spiral bare stent is limited within a reasonable range, so that the bare stent has both flexibility and morphological stability. 3) Due to the setting of the closed-loop structure 4, the flexible connector 5 and the bare stent body will not slip off to cause abnormal morphology of the bare stent. 4) Even if the flexible connector 5 may bend to form a ring on the small curved side, since the ring is roughly parallel to the axial direction of the bare stent, it will not enter the ring when the guide wire, catheter or conveyor is pushed in the subsequent operation, thereby avoiding serious medical accidents such as displacement of the bare stent, failure of instrument push, and even inability to release.

[0039] In one embodiment, in combination Fig.13As shown, the flexible connector 5 is interlaced, wrapped or knotted in the closed loop structure 4 at the oblique beam 3 of the adjacent bare bracket sub-unit, so that the crest 1 and trough 2 of the bare bracket sub-unit are both in a free state, making it more flexible than the technical solution in which the crest 1 and trough 2 are constrained. When the crest 1 and trough 2 are in a free state and the bare bracket sub-units overlap each other, the flexibility and anti-bending performance of the bare bracket is improved.

[0040] In one embodiment, if Figure 19 to Figure 22 As shown, the flexible connector 5 includes a stretchable structure that is sleeved with each other, for example, a first connecting rope 51 and a second connecting rope 52, the first connecting rope 51 is provided with a first knot 511, the second connecting rope 52 is provided with a second knot 521, the first knot 511 is sleeved on the second connecting rope 52, and the second knot 521 is sleeved on the first connecting rope 51 to form a retractable flexible connector 5; when the flexible connector 5 is made of metal wire or metal cable, the first knot 511 and the second knot 521 have good stability and can avoid slipping out of each other (such as Fig.19 When the flexible connector 5 is a suture, due to its weak texture, only the first anti-slip structure 512 can be provided at the end of the first connecting rope 51 without providing the first knot 511. In this case, the second knot 521 of the second connecting rope 52 is not easy to open due to friction (such as Fig. 22 Alternatively, only the second anti-slip structure 522 is provided at the end of the second connecting rope 52 without the second knot 521. In this case, the first knot 511 of the first connecting rope 51 is not easy to open due to friction. Alternatively, both the first knot 511 and the first anti-slip structure 512 and the second knot 521 and the second anti-slip structure 522 are provided (as shown in FIG. Fig.21 As shown), through the above method, the maximum extension length of the first connecting rope 51 and the second connecting rope 52 is limited to avoid separation from each other. The flexible connecting member 5 can also be made of elastic material, so that the flexible connecting member 5 itself has elasticity and can be extended within a certain range.

[0041] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A bare bracket subunit, characterized in that: include: Peaks and troughs set at intervals; An inclined beam, one end of which is used to connect to the wave crest, and the other end of which is used to connect to the wave trough, and the wave crest, the wave trough and / or the inclined beam extend in a circumferential direction to form at least one ring; and a closed-loop structure, wherein the closed-loop structure is arranged on at least one of the wave crest, the wave trough, and the inclined beam.

2. The bare bracket subunit according to claim 1, characterized in that: The wave crests, the oblique beams and the wave troughs are repeatedly arranged to form a ring structure connected end to end.

3. The bare bracket subunit according to claim 2, characterized in that: The ends of the annular structure are connected by sleeve riveting, welding or micro-spring winding.

4. The bare bracket subunit according to claim 1, characterized in that: The wave crests, the oblique beams and the wave troughs are repeatedly arranged to form an open-loop structure with ends disconnected.

5. The bare bracket subunit according to claim 4, characterized in that: The open ring structure is a spiral structure.

6. The bare bracket subunit according to claim 1, characterized in that: The closed loop structure is a full-circle closed loop or a spiral closed loop, and the spiral closed loop includes a single-layer or multi-layer spiral.

7. The bare bracket subunit according to claim 1, characterized in that: The closed-loop structures are staggered with each other in the axial direction of the bare stent subunits.

8. A bare stent, characterized in that: include: One or more bare stent subunits as claimed in any one of claims 1 to 7, wherein the bare stent subunits are arranged in the axial direction; And a flexible connector, which is connected to the closed-loop structure of different bare bracket sub-units.

9. The bare stent according to claim 8, characterized in that: The flexible connector connects the closed-loop structure of different bare stent sub-units axially and / or circumferentially.

10. The bare stent according to claim 8, characterized in that: The flexible connector includes mutually sleeved stretchable structures and / or the flexible connector is elastic.

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