Intravascular stent

Abstract

The utility model relates to an endovascular stent, the whole endovascular stent is of a tubular net structure, the tubular net structure is composed of a plurality of mesh units, a curved bar is arranged in one or more mesh units in the axial direction of the endovascular stent, and when the endovascular stent is pressed and held, the curved bar can stretch in the axial direction of the endovascular stent. According to the stent, the acting force of the stent on the blood vessel wall is more dispersed while the flexibility of the stent is kept and the radial supporting force is increased, and the stent has the advantage of small local pressure intensity.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to an intravascular stent, and in particular to an intravascular self-expanding stent. Background Art

[0002] With the development of the times, compared with traditional open treatment methods, the concept of minimally invasive implantation has been widely recognized and widely used in clinical practice for its advantages of less trauma, faster recovery, and less labor intensity for doctors. As an important component of minimally invasive intervention, the stent system is used in the liver, kidney, urethra, blood vessels and other locations. With the widespread application of stents and the gradual deepening of understanding, higher requirements are placed on the performance of the stent itself.

[0003] In the prior art, the requirements for the flexibility or supporting force of the stent are usually met through structural adjustments and designs such as open loops or closed loops. For example, in order to increase the flexibility of the stent, an open loop structural design is adopted; in order to increase the supporting force, a closed loop structural design is adopted. Of course, there are also ways to increase the width and thickness of the stent rod or to adjust the section length to meet the needs of increasing the radial supporting force of the stent. These structural designs can only meet a single requirement, and it is difficult to meet the requirements of radial force and flexibility at the same time. Moreover, changes in width or thickness may also cause the stent to increase local pressure on the blood vessel wall, stimulate endothelial hyperplasia, and increase the risk of restenosis. Therefore, there is an urgent need for a new design to simultaneously meet the stent's requirements for flexibility and radial supporting force. Summary of the invention

[0004] In view of the limitations of the prior art, the purpose of the present application is to provide a new type of intravascular stent, which solves the problem that the main way to increase radial force in the prior art is to increase the width, thickness and segment length of the stent rod, and replace the main body material through structural design. While maintaining the flexibility of the stent and increasing the radial supporting force, the force of the stent on the blood vessel wall is more dispersed, which has the advantage of low local pressure.

[0005] The purpose of this utility model is achieved through the following technical solutions:

[0006] An intravascular stent is a tubular network structure as a whole, which is composed of a plurality of mesh units. The invention is characterized in that a curved rod is arranged along the axial direction of the intravascular stent in one or more of the mesh units, and when the intravascular stent is compressed and gripped, the curved rod can extend along the axial direction of the intravascular stent.

[0007] The purpose of the utility model can also be further achieved through the following technical solutions:

[0008] In one embodiment, the mesh units in the tubular network structure are all closed structures, and the curved rod is disposed in each mesh unit.

[0009] In one embodiment, a portion of the mesh units in the tubular network structure is a closed structure, and another portion is an open structure, and the curved rod is disposed in each mesh unit of the closed structure.

[0010] In one embodiment, the tubular network structure is formed by connecting a plurality of axially extending corrugated structures, two adjacent corrugated structures are symmetrically arranged along the axial direction of the intravascular stent, and the adjacent corrugated structures are connected to each other to form a plurality of mesh units, and the curved rods are arranged in the mesh units along the axial direction of the intravascular stent.

[0011] In a preferred embodiment, the crests and troughs of two adjacent wave-shaped structures are connected correspondingly.

[0012] In a preferred embodiment, the crests and troughs of two adjacent wave-shaped structures are connected in a staggered manner.

[0013] In a preferred embodiment, two ends of the curved rod are respectively connected to the connection points of the wave crest and the wave trough.

[0014] In a preferred embodiment, two ends of the curved rod are respectively connected to adjacent sinusoidal wave structures.

[0015] In a preferred embodiment, the curved rod is connected between adjacent wave crests and wave troughs.

[0016] In a more preferred embodiment, the curved rod is connected to the middle of adjacent wave crests and wave troughs.

[0017] In the above-mentioned embodiments, the curved rod is a wavy or arc-shaped structure, or the curved rod is a combination of a wavy, straight and arc-shaped structure.

[0018] In a preferred embodiment, the curved rod is composed of a straight line segment, a circular arc chamfered segment and a sinusoidal curve segment.

[0019] In a preferred embodiment, the waveform structure is a sinusoidal waveform.

[0020] In one embodiment, development marks are provided at both ends of the intravascular stent, and the development marks are formed by connecting the crests and troughs at both ends of adjacent wave structures and extending outward.

[0021] In one embodiment, the curved rods are arranged at intervals along the circumference of the intravascular stent.

[0022] In one embodiment, the curved rods are arranged at intervals along the axial direction of the intravascular stent.

[0023] In one embodiment, the curved rods are arranged at intervals along the circumferential direction and the axial direction of the intravascular stent.

[0024] In one embodiment, the length of the curve of the upper portion and the length of the curve of the lower portion of the mesh unit are equal.

[0025] In a preferred embodiment, the length of the upper curve and the length of the lower curve of the mesh unit are both equal to the length of the curved rod after being straightened.

[0026] In one embodiment, the intravascular stent is made of nickel-titanium alloy material.

[0027] In one embodiment, a drug coating is provided on the surface of the intravascular stent to reduce intravascular stenosis.

[0028] In one embodiment, a groove is engraved on the intravascular stent, and a drug is arranged in the groove to achieve the purpose of reducing intravascular stenosis.

[0029] In one embodiment, micropores are provided on the surface of the intravascular stent, and drugs are coated in the micropores to achieve the purpose of reducing intravascular stenosis.

[0030] Compared with the prior art, the utility model has the following advantages:

[0031] 1. The present application provides a curved rod in the mesh unit of the stent, which can increase the radial supporting force of the stent without increasing the rod width and wall thickness of the stent.

[0032] 2. The curved rod of the present application can be arranged at intervals along the circumference of the intravascular stent according to actual use; can be arranged at intervals along the axial direction of the intravascular stent; or can be arranged at intervals along both the circumference and the axial direction of the intravascular stent. Therefore, the radial force and flexibility can be adjusted by adjusting the position of the curved rod in the stent or increasing or decreasing the number of curved rods in the stent.

[0033] 3. The curved rod of the present application is a wavy or arc-shaped structure, and the two ends of the curved rod are respectively connected to the proximal / proximal part and the distal / distal part of the mesh unit. In particular, when the curved rod is composed of a straight segment, an arc chamfered segment and a sine curve segment, this structure can play an auxiliary supporting role. Because, when the stent is subjected to inward pressure from the blood vessel or the detection equipment, the diameter of the stent will decrease, the mesh unit will be compressed, and the distance between the proximal and distal ends of the mesh unit will increase, and the curved rod fixed to the mesh unit at both ends will limit the horizontal extension of the mesh unit, and the arc and curve structure of the curved rod will also prevent its horizontal extension. Therefore, this structure can achieve the purpose of increasing the radial force of the stent. In addition, because the curved rod is a wavy or arc-shaped structure, when the intravascular stent is pressed and gripped, the curved rod of the present application can be straightened along the axial direction of the intravascular stent, so that the pressing and gripping size of the intravascular stent is smaller, which is more convenient for transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the three-dimensional structure of the intravascular stent in the first embodiment of the utility model.

[0035] Figure 2 It is a schematic diagram of the deployment structure of the intravascular stent in the first embodiment of the utility model.

[0036] Figure 3a and Figure 3b It is a schematic diagram of the mesh unit structure of the intravascular stent in the first embodiment of the utility model.

[0037] Figure 4 It is a schematic diagram of the unfolded structure of another implementation of the intravascular stent in Example 1 of the utility model.

[0038] Figure 5 It is a schematic diagram of the deployment structure of the intravascular stent in the second embodiment of the present utility model.

[0039] Figure 6 It is a schematic diagram of the deployment structure of the intravascular stent in the third embodiment of the present utility model.

[0040] Figure 7 It is a structural schematic diagram of an implementation mode of the mesh unit of the intravascular stent in Example 3 of the utility model.

[0041] Figure 8 It is a structural schematic diagram of another implementation of the mesh unit of the intravascular stent in Example 3 of the utility model. DETAILED DESCRIPTION

[0042] The technical solution of the present application and the advantages brought about by it are further described in detail below in conjunction with the accompanying drawings and specific embodiments. Among them, the components in the accompanying drawings are not necessarily drawn to scale, and the focus is on illustrating the concept of the present application.

[0043] Explanation of terms: The “proximal end” mentioned in this application refers to the end close to the surgical operator, and the “distal end” mentioned in this application refers to the end far away from the surgical operator.

[0044] Embodiment 1

[0045] like Figure 1 and Figure 2 As shown, an intravascular stent 1 is a tubular mesh structure as a whole, and the tubular mesh structure is composed of a plurality of mesh units 11. A curved rod 12 is arranged in one or more of the mesh units 11 along the axial direction of the intravascular stent. When the intravascular stent 1 is pressed and gripped, the curved rod 12 can extend along the axial direction of the intravascular stent 1. The tubular mesh structure is formed by connecting a plurality of axially extending wave structures 13. Two adjacent wave structures 13 are symmetrically arranged along the axial direction of the intravascular stent 1. The wave structures 13 connect the proximal end and the distal end of the intravascular stent 1. The adjacent wave structures 13 are connected to each other to form a plurality of mesh units 11. These repetitive mesh units 11 constitute the intravascular stent 1 as a whole with a closed-loop structure. The curved rod 12 is arranged in the mesh unit 11 along the axial direction of the intravascular stent 1. The two ends of the curved rod 12 are respectively connected to the connection points of the wave crest 131 and the wave trough 132. That is to say, the two ends of the curved rod 12 are respectively connected to the proximal end and the distal end of the mesh unit 11, so as to achieve the purpose of reducing the flexibility of the stent while enhancing the radial force of the stent. In one embodiment, the two ends of the curved rod 12 are respectively connected to the connection points of the crest 131 and the trough 132. The crests 131 and troughs 132 of two adjacent wave structures 13 are correspondingly connected, so that the mesh units 11 in the tubular network structure are all closed structures. The wave structure 13 is a sine wave. The curved rod 12 can be arranged at intervals along the axial direction of the intravascular stent 1, or at intervals along the circumferential direction, or at intervals along both the axial direction and the circumferential direction. Figure 2As shown, a plurality of mesh units 11 form an annular structure 110 in the circumferential direction, the curved rods 12 are continuously arranged along the circumferential direction of the annular structure, and the curved rods 12 are not arranged in the adjacent annular structure 110 composed of a plurality of mesh units 11, so that the curved rods 12 are arranged at intervals in the annular structure arranged along the axial direction, and a plurality of mesh units 11 form a belt-like structure 111 along the axial direction of the intravascular stent 1, the curved rods 12 are continuously arranged along the axial direction of the belt-like structure 111, and a plurality of belt-like structures 111 are arranged along the circumferential direction to form a tubular network-like intravascular stent 1, and the curved rods 12 are arranged at intervals in the circumferential direction and in the plurality of belt-like structures 111. In the present application, the curved rods 12 are arranged in the mesh units 11, so that the radial support force of the stent can be increased without increasing the rod width and wall thickness of the stent. The curved rods of the present application can be arranged at intervals along the circumference of the intravascular stent according to actual use; arranged at intervals along the axial direction of the intravascular stent; or arranged at intervals along both the circumference and the axial direction of the intravascular stent. Therefore, the radial force and flexibility can be adjusted by adjusting the position of the curved rods in the stent or increasing or decreasing the number of curved rods in the stent.

[0046] like Figure 1 As shown, the mesh units 11 are connected in sequence as the smallest repeating units to form the tubular network structure of the intravascular stent 1. The number of mesh units 11 in the circumferential direction of the intravascular stent 1 can be selected according to the actual diameter requirement, and the number of mesh units 11 in the axial direction of the intravascular stent 1 can be selected according to the actual length requirement. The crests and troughs at the proximal and distal ends of two adjacent wave structures 13 are connected and extend outward to form a developing structure 14. The number of developing structures 14 can be set as needed. Figure 2 As shown, the number of mesh units 11 in the circumferential direction of the intravascular stent 1 is set to 6; the developing structures 14 are symmetrically set at the proximal and distal ends of the intravascular stent 1 by 3; the rod width of the corrugated structure 13 is 70 microns, the width of the curved rod 12 is 50 microns, and the thickness of the corrugated structure 13 and the curved rod 12 are both 80 microns. The intravascular stent 1 is made of a nickel-titanium alloy tube with a diameter of 2.5 mm, which is laser cut, heat treated and surface treated. Due to the interval arrangement of the curved rod 12, this embodiment can ensure the flexibility of the stent while increasing the radial force, and the stent can be recovered and repositioned when necessary.

[0047] In one embodiment, the curved rod 12 is a wave-shaped or arc-shaped structure, or the curved rod 12 is a combination of a wave-shaped, a straight-line and an arc-shaped structure. Figure 3aAs shown, the curved rod 12 is composed of a straight segment 121, an arc chamfered segment 122 and a sinusoidal curve segment 123. The two ends of the curved rod 12 are respectively connected to the proximal / proximal part and the distal / distal part of the mesh unit 11. In particular, when the curved rod is composed of a straight segment, an arc chamfered segment and a sinusoidal curve segment, this structure can play an auxiliary supporting role. Because when the stent is subjected to inward pressure from a blood vessel or a detection device, the diameter of the stent will decrease, and the mesh unit 11 will be compressed, resulting in an increase in the distance between the proximal and distal ends of the mesh unit 11. The curved rod 12 fixed to the mesh unit 11 at both ends will limit the horizontal extension of the mesh unit 11. The arc and curve structure of the curved rod 12 will also prevent its horizontal extension. Therefore, this structure can achieve the purpose of increasing the radial force of the stent. In addition, as Figure 3b As shown, since the curved rod 12 is a wavy or arc-shaped structure, when the intravascular stent is compressed and gripped, the curved rod 12 of the present application can be straightened along the axial direction of the intravascular stent 1, so that the compression and gripping size of the intravascular stent is smaller and more convenient for transportation. In a preferred embodiment, the length of the curve 111 at the upper part of the mesh unit 11 is equal to the length of the curve 112 at the lower part. In a preferred embodiment, the length of the curve 111 at the upper part of the mesh unit 11 and the length of the curve 112 at the lower part are both equal to the length of the curved rod 12 after being straightened.

[0048] In one embodiment, if Figure 4 As shown, the crests and troughs of two adjacent wave structures 13 are staggered and connected, and the two ends of the curved rod 12 are respectively connected to the adjacent sine wave structures. In a preferred embodiment, the curved rod 12 is connected between the adjacent crests and troughs. In another embodiment, the curved rod 12 is connected between the adjacent crests and troughs.

[0049] In one embodiment, the intravascular stent 1 is made of nickel-titanium alloy material.

[0050] In one embodiment, a drug coating is provided on the surface of the intravascular stent 1 to achieve the purpose of reducing intravascular stenosis; in another embodiment, grooves are engraved on the intravascular stent 1, and drugs are provided in the grooves to achieve the purpose of reducing intravascular stenosis; in yet another embodiment, micropores are provided on the surface of the intravascular stent 1, and drugs are coated in the micropores to achieve the purpose of reducing intravascular stenosis.

[0051] Embodiment 2

[0052] The structure of this embodiment is basically the same as that of the first embodiment. The difference between them is that: Figure 5As shown, the mesh units 11 in the tubular mesh structure are all closed structures, and the curved rod 12 is arranged in each mesh unit 11. The number of mesh units 11 in the circumferential direction of the intravascular stent 1 is set to 6; the developing structure 14 is symmetrically arranged at the proximal end and the distal end of the intravascular stent 1, and the rod width of the corrugated structure 13 is 130 microns, the width of the curved rod 12 is 70 microns, and the thickness of the corrugated structure 13 and the curved rod 12 are both 200 microns. The intravascular stent 1 is made of a nickel-titanium alloy tube with a diameter of 2.5 mm, which is laser cut and heat-treated to expand the diameter to 6 mm, and then surface-treated (such as electrochemical polishing). Since the diameter is expanded by heat treatment after cutting from a small diameter pipe, the full mesh setting of the curved rod 12 and the middle section of the curved rod 12 are sinusoidal wave designs, this embodiment can improve the metal utilization rate of the pipe, greatly improve the radial force of the stent, and ensure the flexibility of the stent, and the stent can be recovered and repositioned when necessary.

[0053] Embodiment 3

[0054] The structure of this embodiment is basically the same as that of the first embodiment. The difference between them is that: Figure 6 As shown, an intravascular stent 1 is a tubular mesh structure as a whole, and the tubular mesh structure is composed of a plurality of mesh units 11. A curved rod 12 is arranged in one or more of the mesh units 11 along the axial direction of the intravascular stent. When the intravascular stent 1 is pressed and gripped, the curved rod 12 can extend along the axial direction of the intravascular stent 1. A portion of the tubular mesh structure is a closed mesh unit 113, and a portion is an open mesh unit 114. The curved rod 12 is arranged in each of the closed mesh units 113. The closed mesh unit 113 means that there is no opening on the corrugated structure constituting the mesh unit 11, and the open mesh unit 114 means that there is an opening 115 on the corrugated structure constituting the mesh unit 11. It can also be said that the corrugated structure constituting the intravascular stent 1 is not continuously connected from the proximal end to the distal end, but is arranged at intervals, so that an open-loop stent structure is finally formed. The open-loop structural design increases the flexibility of the stent. In one embodiment, the circumferentially adjacent mesh units 11 are not directly connected at the crests and troughs, but are staggered at the crests and troughs. The closed mesh units 113 arranged in the axial direction are not connected to each other, but are partially connected. In another embodiment, a part of the mesh units 11 of the intravascular stent 1 are connected at the crests and troughs, and another part of the mesh units 11 are staggered at the crests and troughs. In yet another embodiment, the mesh units 11 of the intravascular stent 1 are staggered at the crests and troughs, but when the crests and troughs of the mesh units 11 at different positions are staggered, the offset of the stagger is different.

[0055] In this embodiment, the number of mesh units 11 in the circumferential direction of the intravascular stent 1 is set to 6; the rod width of the corrugated structure 13 is 70 microns, the width of the curved rod 12 is 50 microns, and the thickness of the corrugated structure 13 and the curved rod 12 are both 80 microns. The intravascular stent 1 is made of a cobalt-chromium alloy tube with a diameter of 2.5 mm after laser cutting, blanking, and surface treatment. Due to the interval setting of the curved rod 12 and the structure of the open-loop stent, this embodiment can ensure the flexibility of the stent while increasing the radial force.

[0056] like Figure 7 and Figure 8 As shown, the two ends of the curved rod 12 are not respectively connected to the proximal end and the distal end of the mesh unit 11. Instead, one end of the curved rod 12 is connected to the upper curve 111 of the mesh unit 11, and the other end of the curved rod 12 is connected to the lower curve 112 of the mesh unit 11.

[0057] It should be noted that the above embodiments are only partial examples. Whether the crests and troughs of the waveform structure are connected in correspondence, or whether the crests and troughs are staggered, the number and distribution of the curved rods in the mesh unit, the structural type of the curved rods, and the connection positions of the curved rods can be cross-combined and exist in the same or different support structures.

[0058] The above detailed description of the utility model is intended to enable people familiar with the technology in this field to understand the content of the utility model and implement it. It is not intended to limit the protection scope of the utility model. All equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. An intravascular stent, which is a tubular network structure as a whole, and the tubular network structure is composed of a plurality of mesh units, characterized in that: A curved rod is arranged in one or more of the mesh units along the axial direction of the intravascular stent. When the intravascular stent is compressed and gripped, the curved rod can extend along the axial direction of the intravascular stent. A part of the mesh units in the tubular network structure is a closed structure, and another part is an open structure. The curved rod is arranged in each mesh unit of the closed structure.

2. The intravascular stent according to claim 1, characterized in that: The mesh units in the tubular network structure are all closed structures, and the curved rod is arranged in each mesh unit.

3. The intravascular stent according to claim 1, characterized in that: The tubular network structure is formed by connecting a plurality of axially extending wave structures, two adjacent wave structures are symmetrically arranged along the axis of the intravascular stent, and the adjacent wave structures are connected to each other to form a plurality of mesh units.

4. The intravascular stent according to claim 3, characterized in that: The crests and troughs of two adjacent wave structures are connected correspondingly.

5. The intravascular stent according to claim 3, characterized in that: The crests and troughs of two adjacent wave structures are connected in a staggered manner.

6. The intravascular stent according to claim 3, characterized in that: The two ends of the curved rod are respectively connected to the connection points of the wave crest and the wave trough.

7. The intravascular stent according to claim 3, characterized in that: Both ends of the curved rod are connected to adjacent wave-shaped structures respectively.

8. The intravascular stent according to claim 3, characterized in that: The waveform structure is a sine waveform.

9. The intravascular stent according to claim 1, characterized in that: The curved rod is a wave-shaped or arc-shaped structure, or the curved rod is a combined structure of a wave-shaped, straight-line and arc-shaped structure.

10. The intravascular stent according to claim 1, characterized in that: The curved rods are arranged at intervals along the circumferential direction of the intravascular stent, or the curved rods are arranged at intervals along the axial direction of the intravascular stent, or the curved rods are arranged at intervals along both the circumferential direction and the axial direction of the intravascular stent.

11. The intravascular stent according to claim 1, characterized in that: The length of the curve of the upper portion of the mesh unit is equal to the length of the curve of the lower portion.

12. The intravascular stent according to claim 1, characterized in that: The curved rod is composed of a straight line segment, a circular arc chamfered segment and a sine curve segment.

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