A degradable vascular stent

Abstract

The invention relates to a degradable vascular stent, which belongs to the technical field of vascular stent design. The invention solves the problems of safety of vascular stent implantation process in the prior art and targeted provision of vascular support for different vascular lesions. The degradable vascular stent is in the shape of an elongated cylinder and comprises: a plurality of support rings arranged in parallel with each other in the longitudinal direction of the degradable vascular stent, and a plurality of connectors connecting the longitudinally adjacent support rings; wherein the support rings are corrugated and extend circumferentially and enclose a ring shape, and the support rings are composed of a plurality of herringbone substructures connected in a symmetrical alternating manner; the herringbone substructures comprise a vertex and side edges symmetrically extending from the vertex to both sides; wherein an end circular arc protruding outward is formed at the vertex; and each of the side edges comprises a circular arc chamfer and a straight line segment extending from the end circular arc.

Description

Technical Field

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

[0002] Cardiovascular diseases (CVDs) are one of the major global health problems, and coronary stents are widely used to treat coronary artery lesions. However, traditional metal stents may cause problems such as vascular restenosis due to their non-degradability. Therefore, degradable biomaterial stents have become the development trend in this field. Poly(lactic acid) (PLLA), as a biodegradable polymer, has been applied to the design of degradable stents due to its good biocompatibility and degradation characteristics.

[0003] The structural design of PLLA stents in the prior art ignores the synergistic effect of the overall structure of the stent, the support rings, and the connectors. This results in poor radial mechanical properties, morphology, and stability during the crimping process, affecting the clinical application effect of the stent. In addition, for patients with conditions such as plaques and vascular stenosis in the blood vessels, the existing general vascular stent structures are difficult to specifically adapt to and meet their special conditions and needs.

[0004] Chinese Utility Model Patent, Publication No. CN201564638U, Utility Model Name "A Degradable Vascular Stent", discloses a degradable vascular stent, including strips, and a tooth and lock structure at the connection ends of the strips for fixing the strips into a cylindrical shape. The strips of this structure are only longitudinally connected at the connection ends, resulting in uneven force on the structure, easy deformation, and a risk of damaging the blood vessels with the sharp teeth when being delivered into the blood vessels.

[0005] Chinese Utility Model Patent, CN206761807U, Utility Model Name "Degradable Spiral Vascular Stent", discloses a spiral vascular stent which is in the form of circular threads uniformly arranged longitudinally. It has poor radial resilience, causing difficulties in installation and implantation, and cannot meet the individual differences of blood vessels with lesions or special conditions.

[0006] Therefore, there is a need in this field for an improved degradable vascular stent that can be easily and safely implanted, has uniform force and minimizes stress concentration, and can adapt to different vascular lesion conditions to provide a safe and effective vascular support effect. Summary of the Invention

[0007] Aiming at the problems such as insufficient mechanical properties in the structure of degradable vascular stents in the prior art, the present invention provides a degradable vascular stent, and this solution greatly improves the structural performance of the degradable vascular stent.

[0008] The present invention provides a degradable vascular stent, which is in the shape of a long cylinder and includes: a plurality of support rings arranged parallel to each other in the longitudinal direction of the degradable vascular stent, and a plurality of connectors connecting the longitudinally adjacent support rings; wherein, the support rings are corrugated and extend circumferentially to enclose a ring shape, and the support rings are formed by connecting a plurality of chevron-shaped sub-structures in a symmetrically alternating manner; the chevron-shaped sub-structures include vertices, and side edges symmetrically extending from the vertices to both sides; wherein an end arc protruding outward is formed at the vertex; each of the side edges includes an arc chamfer extending from the end arc and a straight line segment.

[0009] Optionally, the ratio of the length of the connector in the longitudinal direction to the length of the support ring in the longitudinal direction is 2.4 to 2.8 times; the ratio of the width of the connector in the circumferential direction to the width of the strip material of the support ring is 0.6 to 1.2 times.

[0010] Optionally, the connectors between the longitudinally adjacent support rings form a connector dense area and a connector sparse area; wherein, the connector dense area has 6 connectors between the longitudinally adjacent support rings; the connector sparse area has 3 connectors between the longitudinally adjacent support rings.

[0011] Optionally, the support ring includes 12 chevron-shaped sub-structures; in the connector dense area, the connectors adjacent to each other in the circumferential direction are spaced apart by one end arc; in the connector sparse area, the connectors adjacent to each other in the circumferential direction are spaced apart by three end arcs.

[0012] Optionally, the degradable vascular stent has two connector dense areas, which are arranged at its longitudinal two ends; between the connector dense areas at both ends is the connector sparse area.

[0013] Optionally, the degradable vascular stent includes 8 support rings, as well as 2 connector dense areas and 5 connector sparse areas; wherein, the 2 connector dense areas are respectively arranged between the third support ring and the fourth support ring at the longitudinal left end of the degradable vascular stent, and between the fifth support ring and the sixth support ring at the longitudinal left end; the positions between the other support rings are the connector sparse areas.

[0014] Optionally, the degradable vascular stent includes 8 support rings, as well as 3 connector dense areas and 4 connector sparse areas; wherein, the 3 connector dense areas are respectively arranged between the first support ring and the second support ring at the longitudinal left end of the degradable vascular stent, between the fourth support ring and the fifth support ring, and between the seventh support ring and the eighth support ring; the positions between the other support rings are the connector sparse areas.

[0015] Optionally, the connector is a double Y-shaped connector, including a middle part and end parts with gradually expanding cross-sectional dimensions from the middle part towards both ends; wherein, the end parts of the double Y-shaped connector are respectively connected to the corresponding end arcs of two longitudinally adjacent support rings; the cross-sectional dimension of the middle part of the double Y-shaped connector is smaller than the cross-sectional dimensions of both ends.

[0016] Optionally, the connector is a convex connector, including vertical parts at both ends and multiple arc parts connecting the vertical parts; wherein, the ends of the vertical parts of the convex connector are respectively connected to the corresponding end arcs of two longitudinally adjacent support rings; the multiple arc parts include a first arc segment with a radius of R1, a second arc segment with a radius of R2, a third arc segment with a radius of R3, and a fourth arc segment with a radius of R4 that are connected in sequence.

[0017] Optionally, the radius R2 of the second arc segment is greater than the radius R1 of the first arc segment, and the radius R3 of the third arc segment is greater than the radius R4 of the fourth arc segment.

[0018] Compared with the prior art, a degradable vascular stent provided by the present invention has at least the following beneficial effects.

[0019] (1) Compared with the existing degradable vascular stent structures, the degradable vascular stent structure proposed by the present invention has the advantages of simple structure, convenient processing and manufacturing, etc.

[0020] (2) The design scheme of the polylactic acid vascular stent structure proposed by the present invention can significantly improve the radial mechanical properties and crimping properties of the stent, reduce the damage or destruction of the support rings during crimping and expansion, and improve the long-term clinical effect.

[0021] (3) The present invention reasonably designs the geometry of the support rings and connectors of the stent, strengthens the mutual cooperation mechanism between the support rings and connectors, enables the deformation mode of the vascular stent to be more ideal during crimping and expansion, and reduces the damage caused by stress concentration, etc.

[0022] (4) The layout of the connector encryption area and sparse connectors provided by the present invention can ensure that the deformation mode of the degradable vascular stent is more regular during crimping and expansion, improve the radial mechanical properties of the degradable vascular stent, and at the same time ensure good bending performance.

[0023] (5) The various layout methods of the connector encryption area and sparse connectors provided by the present invention can respectively meet the needs of patients with different vascular conditions, and provide a more accurate and effective vascular support effect adapted to individual differences.

[0024] (6) The double Y-shaped connector and convex connector proposed by the present invention can reduce the damage of the support rings and improve the bending performance of the stent. Description of the Drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. By referring to the drawings, the features and advantages of the present invention can be more clearly understood. The drawings are schematic and should not be construed as imposing any limitations on the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 It is a schematic diagram of a degradable vascular stent provided according to the first embodiment of the present invention.

[0027] Figure 2 It is a schematic diagram of the deployment of a degradable vascular stent provided according to the first embodiment of the present invention.

[0028] Figure 3 It is an enlarged schematic diagram of the deployment of a single sub-structure of a degradable vascular stent provided according to the first embodiment of the present invention.

[0029] Figure 4a It is a schematic diagram of a degradable vascular stent provided according to the second embodiment of the present invention.

[0030] Figure 4b It is a schematic diagram of the deployment of a degradable vascular stent provided according to the second embodiment of the present invention.

[0031] Figure 5a It is a schematic diagram of a degradable vascular stent provided according to the third embodiment of the present invention.

[0032] Figure 5b It is a schematic diagram of the deployment of a degradable vascular stent provided according to the third embodiment of the present invention.

[0033] Figure 6a It is a schematic diagram of a degradable vascular stent provided according to the fourth embodiment of the present invention.

[0034] Figure 6b It is a schematic diagram of the deployment of a degradable vascular stent provided according to the fourth embodiment of the present invention.

[0035] Figure 7 It is a schematic diagram of a double Y-shaped connector of a degradable vascular stent provided according to the fifth embodiment of the present invention.

[0036] Figure 8 It is a schematic diagram of a convex connector of a degradable vascular stent provided according to the sixth embodiment of the present invention.

[0037] Figure 9It is a partially enlarged schematic view of the convex connector of the degradable vascular stent provided according to the sixth embodiment of the present invention.

[0038] Reference numerals:

[0039] 1. Support ring; 2. Connector; 3. Sawtooth wave center line; 4. Straight segment; 5. Arc chamfer; 6. End arc; 7. Axis of symmetry; 8. Inscribed circle of the sawtooth wave center line; 9. Connector encryption area; 10. Connector sparse area; 14. Double Y-shaped connector; 15. Convex connector; 15-1. First arc segment; 15-2. Second arc segment; 15-3. Third arc segment; 15-4. Fourth arc segment; 15-5. Vertical part. Detailed implementation manners

[0040] In order to more clearly understand the above objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0041] Many specific details are set forth in the following description in order to fully understand the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0042] The following provides a detailed description of a degradable vascular stent according to an embodiment of the present invention with reference to the drawings.

[0043] The degradable vascular stent provided by the present invention includes an improved support ring and a connector, solves the problem of insufficient mechanical properties of the polylactic acid vascular stent, and proposes a degradable vascular stent made of polylactic acid material with excellent mechanical properties.

[0044] As Figure 1 and Figure 2 shown, according to the first embodiment of the present invention, a degradable vascular stent is provided, which is made of polylactic acid material and includes a plurality of support rings 1 and a plurality of connectors 2. Among them, the support ring 1 is corrugated and extends circumferentially to form a ring, and the connector 2 is connected to the support rings 1 adjacent in the longitudinal direction. As Figure 1 shown, the degradable vascular stent of this embodiment is in the shape of a long cylinder in a conventional state such as the use state, its circular direction is the circumferential direction, and its long extension direction is the longitudinal direction. Optionally, the degradable vascular stent may include 6 to 12 support rings 1, and a plurality of connectors 2 are used to connect adjacent support rings 1 to form a long cylindrical degradable vascular stent. Optionally, between two adjacent support rings 1 in the longitudinal direction, 2 to 8 connectors 2 may be used for connection. For example, as Figure 2The planar development view of the degradable vascular stent provided by this embodiment is shown. Adjacent support rings 1 can be connected by three connectors 2, and the connectors 2 are arranged alternately in the longitudinal direction. Optionally, the total length of the degradable vascular stent can be set according to the length or size of the plaque of the stent user; the outer diameter of the degradable vascular stent can be set according to the blood vessel diameter of the stent user. Optionally, the arrangement of the connectors 2 of the support rings 1 of the degradable vascular stent can also be encrypted as needed, for example, encrypted according to the size of the plaque detected in the stent user. Optionally, the support rings 1 are arranged parallel to each other in the longitudinal direction of the degradable vascular stent, and the spacing distances between longitudinally adjacent support rings 1 are the same. Optionally, the degradable vascular stent can be integrally formed.

[0045] Reference Figure 1 , the length of the connector 2 of the degradable vascular stent of this embodiment in the longitudinal direction is L, and the width in the circumferential direction is T2.

[0046] Continue to refer to Figure 1 , the length of the corrugated support ring 1 in the longitudinal direction is H, and the width of the strip material forming the support ring 1 is T1. As Figure 3 The development view of the sub-structure of the support ring 1 of the degradable vascular stent provided by this embodiment is shown. The support ring 1 of the degradable vascular stent can be formed into a ring by continuously arranging the sub-structures in a symmetrically alternating manner.

[0047] The length of the sawtooth wave center line 3 along the circumference of the degradable vascular stent is the circumference of the degradable vascular stent, and twice the amplitude of the sawtooth wave center line 3 is the length H of the support ring in the longitudinal direction. The specific dimensions of the sawtooth wave can be calculated from the total length of the degradable vascular stent, the outer diameter of the degradable vascular stent, the proportional relationship between H and L, and the width T1 of the strip material of the support ring.

[0048] As Figure 3 shown, the sub-structure of the support ring 1 of the degradable vascular stent is based on the sawtooth wave center line 3, and the sawtooth wave center line 3 is triangular. The sub-structure of the support ring 1 is generally a herringbone structure, including a vertex, and is symmetric about the symmetry axis 7 extending longitudinally from the vertex. The symmetry axis 7 is parallel to the central axis of the degradable vascular stent. Specifically, the sub-structure of the support ring 1 is generally a herringbone structure, including a vertex, and side edges symmetrically extending from the vertex to both sides; an end arc 6 protruding outward is formed at the vertex; the side edges may include a straight line segment 4, and an arc chamfer 5 connecting the end arc 6 of the vertex and the straight line segment 4. The protruding direction of the arc chamfer 5 is towards the inside of the herringbone structure of the sub-structure. See Figure 2, the support ring 1 includes multiple sub-structures connected in a symmetric and alternating manner, that is, each sub-structure and the adjacent sub-structure are in a form that is inverted with respect to each other longitudinally, so that the end arc 6, the arc chamfer 5, and the straight line segment 4 are continuously connected in sequence, jointly forming a corrugated structure.

[0049] Continue to refer to Figure 3 , the straight line segment 4 is obtained by offsetting the center line 3 of the sawtooth wave by half of the width of the support ring 1 equidistantly on both sides , the arc chamfer 5 connects the straight line segment 4 and the end arc 6, and the end arc 6 is obtained by translating the inscribed circle 8 of the sawtooth wave center line upward and downward by half of the width of the support ring 1 , the end arc 6 is connected to the straight line segment 4 through the arc chamfer 5, and the end arc 6 bulges above the vertex of the sub-structure. The radius of the inscribed circle 8 of the sawtooth wave center line is R, and the size of this radius R can be set according to the cross-sectional radius of the degradable vascular stent. For example, the range of this radius R can be set to 0.2 mm to 0.6 mm as needed. The strip material forming the support ring 1 has a uniform width T1, that is, the end arc 6, the straight line segment 4, and the arc chamfer 5 of the support ring 1 have the same width. For example, Figure 3 the left side part of the sub-structure shown includes, from top to bottom, the end arc 6, the arc chamfer 5, the straight line segment 4, the arc chamfer 5, and the end arc 6, which are altogether composed of 4 arc segments and the straight line segment 4. In this embodiment, the projection length of the straight line segment 4 on the central axis of the degradable vascular stent should be less than 1 / 5 of the length H of the support ring 1.

[0050] A corrugated support ring 1 extending in the circumferential direction can be formed by alternately connecting the above-mentioned sub-structures and symmetric sub-structures to enclose a circumferentially closed structure. Through the support ring 1 of the sub-structure including the end arc 6, the straight line segment 4, and the arc chamfer 5 connecting the end arc 6 and the straight line segment 4, each part of the degradable vascular stent in this embodiment can be made more smooth, ensuring the safety of the degradable vascular stent during use.

[0051] Continue to refer to Figure 1 and Figure 2 , the degradable vascular stent of the first embodiment can be formed into a longitudinally extending cylindrical structure by connecting the adjacent corrugated support rings 1 in the longitudinal direction through the connector 2. Among them, the adjacent corrugated support rings 1 are arranged parallel to each other, the connector 2 can be connected at the end arc 6 of the support ring 1, and each connector 2 connects the corresponding end arc 6 in the longitudinal direction of the adjacent support rings 1. In the first embodiment, a complete support ring 1 includes 12 sub-structures, that is, it includes 12 end arcs 6. It should be understood that according to needs, in other embodiments, the support ring 1 can be formed by connecting more or fewer sub-structures in a symmetric and alternating manner.

[0052] In this embodiment, on the circumferential corrugated support ring 1, the connector 2 is connected to the support ring 1 at an interval of three end arcs 6. Optionally, as Figure 2 shown, the position where the connector 2 is connected to the first corrugated support ring 1 and the second corrugated support ring 1 at the left end is alternately spaced from the position where the connector 2 is connected to the second corrugated support ring 1 and the third corrugated support ring 1. In other words, the connection position of the connector 2 connecting the first and second corrugated support rings 1 to the second corrugated support ring 1 is spaced from the connection position of the connector 2 connecting the second and third corrugated support rings 1 to the second corrugated support ring 1 by one end arc 6 each. The setting of the connector 2 between other longitudinally adjacent connection rings 2 of the degradable vascular stent can be inferred by analogy. The degradable vascular stent with the above structural setting can ensure uniform overall force and avoid deformation and damage caused by local force concentration.

[0053] Optionally, the ratio of the length L of the connector 2 to the length H of the support ring 1 can be set in the range of 2.4 - 2.8, and the ratio of the width T2 of the connector 2 to the width T1 of the support ring 1 can be set in the range of 0.6 - 1.2, so that the crimping performance of the degradable vascular stent is better and the crimping deformation mode is more regular, thereby ensuring less damage to the blood vessel wall after the degradable stent is expanded.

[0054] To further improve the mechanical properties of the degradable vascular stent and meet the needs of different patients, the degradable vascular stent according to another embodiment of the present invention will be described below.

[0055] As Figure 4a and Figure 4b shown, a schematic diagram and a plane development diagram of the degradable vascular stent according to the second embodiment of the present invention are shown. The degradable vascular stent provided in this embodiment includes a plurality of corrugated support rings 1 and connectors 2 connecting longitudinally adjacent corrugated support rings 1, wherein the connectors 2 between two adjacent corrugated support rings 1 form a connector dense area 9 and a connector sparse area 10 according to the quantity. In this embodiment, the connector dense area 9 has 3 connectors 2 with uniform intervals between two adjacent corrugated support rings 1, and the connector sparse area 10 has 6 connectors 2 with uniform intervals between two adjacent corrugated support rings 1. In this embodiment, the connector dense area 9 is provided at the longitudinal two ends of the degradable vascular stent, and the middle area is the connector sparse area 10. The connector sparse area 10 in the middle area follows the position of the connectors 2 of the longitudinally adjacent connector sparse areas 10 being staggered from each other.

[0056] As Figure 4a and Figure 4bAs shown, the degradable vascular stent of this embodiment includes two connector encryption regions 9, which are arranged at the longitudinal left end and the longitudinal right end of the degradable vascular stent. That is, between the first corrugated support ring 1 and the second corrugated support ring 1 on the longitudinal left side is the connector encryption region 9, and between the last corrugated support ring 1 on the longitudinal left side and its adjacent corrugated support ring 1 is the connector encryption region 9. Between the connector encryption regions 9 at both ends is the connector sparse region 10. Each corrugated support ring 1 includes 12 end arcs 6. In this connector encryption region 9, the number of connectors 2 between longitudinally adjacent support rings 1 is set to 6, and there is an interval of 1 end arc 6 between circumferentially adjacent connectors 2. In the connector sparse region 10, the number of connectors 2 between longitudinally adjacent support rings 1 is set to 3, and there is an interval of 3 end arcs 6 between circumferentially adjacent connectors 2. Figure 4a and Figure 4b As shown, the degradable vascular stent of this embodiment includes 8 corrugated support rings 1. However, in other embodiments, more or fewer corrugated support rings 1 can be provided as needed.

[0057] The arrangement of this second embodiment is beneficial to reducing the dog-bone effect of the degradable vascular stent, improving the crimp deformation of the stent, and having less influence on the bending performance (flexibility) of the stent. Other aspects of this second embodiment, such as the structure of the corrugated support ring 1 and its sub-structures, are similar to those of the first embodiment and will not be elaborated here.

[0058] As Figure 5a and Figure 5b As shown, a schematic diagram and a planar unfolded diagram of a degradable vascular stent according to a third embodiment of the present invention are shown. The degradable vascular stent provided by this third embodiment includes a connector encryption region 9 provided in the longitudinal middle of the degradable vascular stent. Specifically, the degradable vascular stent of this embodiment includes 8 support rings 1, 2 connector encryption regions 9, and 5 connector sparse regions 10; among them, between the third support ring 1 and the fourth support ring 1 at the longitudinal left end is the connector encryption region 9, and between the fifth support ring 1 and the sixth support ring 1 at the left end is the connector encryption region 9, and the other positions are connector sparse regions 10. In this connector encryption region 9, the number of connectors 2 between adjacent support rings 1 is set to 6, and there is an interval of 1 end arc 6 between circumferentially adjacent connectors 2. In the connector sparse region 10, 3 connectors 2 are provided between adjacent support rings 1, and there is an interval of 3 end arcs 6 between circumferentially adjacent connectors 2.

[0059] The arrangement of the third embodiment is conducive to improving the crimping deformation of the degradable vascular stent and can effectively prevent the collapse of the degradable vascular stent during long-term use. Other aspects of the third embodiment, such as the structure of the corrugated support ring 1 and its sub-structures, are similar to those of the first embodiment and will not be elaborated here.

[0060] As Figure 6a and Figure 6b shown, a schematic diagram and a planar development view of a degradable vascular stent according to a fourth embodiment of the present invention are shown. The degradable vascular stent provided by this fourth embodiment includes connector encryption areas 9 provided at both the longitudinal middle part and the two end parts of the degradable vascular stent. Specifically, the degradable vascular stent of this embodiment includes 8 support rings 1, as well as 3 connector encryption areas 9 and 4 connector sparse areas 10; among them, between the first support ring 1 and the second support ring 1 at the longitudinal left end is the connector encryption area 9, between the fourth support ring 1 and the fifth support ring 1 is the connector encryption area 9, and between the seventh support ring 1 and the eighth support ring 1 is the connector encryption area 9, and the other parts are connector sparse areas 10. Among them, in the connector encryption area 9, the number of connectors 2 between adjacent support rings 1 is set to 6, and there is an end arc 6 spaced between adjacent connectors 2 in the circumferential direction. In the connector sparse area 10, the number of connectors 2 between adjacent support rings 1 is set to 3, and there are 3 end arcs 6 spaced between circumferentially adjacent connectors 2.

[0061] This arrangement of the fourth embodiment can significantly improve the crimping performance of the degradable vascular stent and effectively improve the support performance of the degradable vascular stent.

[0062] As Figure 7 shown, a schematic diagram of another connector of a degradable vascular stent according to a fifth embodiment of the present invention is shown. To further improve the bending performance of the stent, this embodiment provides a double-Y-shaped connector 14. The double-Y-shaped connector 14 includes a middle part and end parts whose cross-sectional dimensions gradually expand from the middle part to both ends, forming an approximately symmetrically spliced double-Y-shaped structure. The end parts of the double-Y-shaped connector 14 are respectively connected to the corresponding end arcs 6 of two longitudinally adjacent support rings 1. Among them, the cross-sectional dimension of the middle part of the double-Y-shaped connector 14 is smaller than the cross-sectional dimensions of both ends. The double-Y-shaped connector 14 provided by this fifth embodiment has a significant effect on improving the bending performance of the degradable vascular stent.

[0063] As Figure 8 and Figure 9As shown, a schematic diagram of another connector of the degradable vascular stent according to the sixth embodiment of the present invention is shown. To further improve the bending performance of the stent, this embodiment provides a convex connector 15 with a lateral protrusion perpendicular to the central axis of the degradable vascular stent. The connector 15 is continuously formed by vertical portions 15-5 at both ends and multiple arc portions between the vertical portions 15-5. The vertical portions 15-5 are respectively connected to the corresponding end arcs 6 of two longitudinally adjacent support rings 1. Specifically, the multiple arc portions include a first arc segment 15-1 with a radius of R1, a second arc segment 15-2 with a radius of R2, a third arc segment 15-3 with a radius of R3, and a fourth arc segment 15-4 with a radius of R4, which are connected in sequence. Specifically, the multiple arc portions can be arranged to include: a central fourth arc segment 15-4, and third arc segments 15-3, second arc segments 15-2, and first arc segments 15-1 that symmetrically extend from it to both sides respectively. Among them, adjacent arc segments are tangent at the intersection points, so that the multiple arc segments are smoothly connected, and the protrusion directions of adjacent arc segments are opposite. For example, the first arc segment 15-1 with a radius of R1 protrudes to the left, the second arc segment 15-2 with a radius of R2 protrudes to the right, the third arc segment 15-3 with a radius of R3 protrudes to the left, and the fourth arc segment 15-4 with a radius of R4 protrudes to the right. Optionally, the sizes of the radii R1, R2, R3, and R4 can be set to increase first and then decrease, that is, the sizes of the radii R2 and R3 are larger than the sizes of the radii R1 and R4. In other words, the convex connector 15 of this embodiment includes a middle portion protruding to one circumferential side of the degradable vascular stent, and vertical portions 15-5 extending from the middle portion to both ends respectively. The ends of the two vertical portions 15-5 of the convex connector 15 are respectively connected to the corresponding end arcs 6 of two longitudinally adjacent support rings 1. The convex connector 15 provided by this sixth embodiment has a significant effect on improving the bending performance of the degradable vascular stent.

[0064] All of the above optional technical solutions can be combined arbitrarily to form optional embodiments of the present application, which will not be elaborated here one by one.

[0065] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0066] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A degradable vascular stent, characterized in that: The degradable blood vessel stent is in the shape of a long cylinder and comprises: a plurality of support rings arranged parallel to each other in the longitudinal direction of the degradable blood vessel stent, and a plurality of connectors connecting the support rings adjacent to each other in the longitudinal direction; The support ring is corrugated and extends in the circumferential direction to form a ring, and the support ring is composed of a plurality of herringbone substructures connected in a symmetrical and alternating manner; The herringbone substructure includes a vertex, and side edges extending symmetrically from the vertex to both sides; wherein an end arc protruding outward is formed at the vertex; each of the side edges includes an arc chamfer and a straight line segment extending from the end arc; The ratio of the length of the connector in the longitudinal direction to the length of the support ring in the longitudinal direction is 2.4 to 2.8; The connectors between the longitudinally adjacent support rings constitute a connector density area and a connector sparse area; In the connector densification area, adjacent connectors in the circumferential direction are spaced apart by an end arc; In the connector sparse area, the connectors adjacent to each other in the circumferential direction are spaced apart by three end arcs; The degradable vascular stent is made of polylactic acid material; The spacing distances between the longitudinally adjacent support rings are all the same; Each connector connects corresponding end arcs of adjacent support rings in the longitudinal direction.

2. The degradable vascular stent according to claim 1, characterized in that: The ratio of the width of the connector in the circumferential direction to the width of the strip material of the support ring is 0.6 to 1.

2.

3. The degradable vascular stent according to claim 1, characterized in that: in, The connector encryption area has 6 connectors between longitudinally adjacent support rings; The connector sparse area has three connectors between longitudinally adjacent support rings.

4. The degradable vascular stent according to claim 3, characterized in that: The degradable blood vessel stent has two connector density areas, which are arranged at two longitudinal ends thereof; and a connector sparse area is between the connector density areas at the two ends.

5. The degradable vascular stent according to claim 3, characterized in that: The degradable vascular stent comprises 8 support rings, 2 connector dense areas and 5 connector sparse areas; The two connector density areas are respectively arranged between the third support ring and the fourth support ring at the longitudinal left end of the degradable vascular stent, and between the fifth support ring and the sixth support ring at the longitudinal left end; the positions between the other support rings are connector sparse areas; Among them, between the second support ring and the third support ring, between the third support ring and the fourth support ring, between the fourth support ring and the fifth support ring, between the fifth support ring and the sixth support ring, and between the sixth support ring and the seventh support ring, there are respectively three connectors arranged at corresponding longitudinal positions, and at the corresponding longitudinal positions, the corresponding end arc of the second support ring is connected to the end arc of the sixth support ring through the five connectors in the longitudinal direction.

6. The degradable vascular stent according to claim 3, characterized in that: The degradable vascular stent comprises 8 support rings, 3 connector dense areas and 4 connector sparse areas; Among them, the three connector encrypted areas are respectively arranged between the first support ring and the second support ring at the longitudinal left end of the degradable vascular stent, between the fourth support ring and the fifth support ring, and between the seventh support ring and the eighth support ring; the positions between the other support rings are connector sparse areas.

7. The degradable vascular stent according to claim 1, characterized in that: The connector is a double Y-shaped connector, comprising a middle portion, and ends whose cross-sectional dimensions gradually expand from the middle portion to both ends; Wherein, the ends of the double Y-shaped connector are respectively connected to the corresponding end arcs of two longitudinally adjacent support rings; The cross-sectional dimensions of the middle portion of the double Y-shaped connector are smaller than the cross-sectional dimensions of the two ends.

8. The degradable vascular stent according to claim 1, characterized in that: The connector is a male connector, comprising vertical parts at both ends and multiple arc parts connecting the vertical parts; wherein the ends of the vertical portion of the male connector are respectively connected to corresponding end arcs of two longitudinally adjacent support rings; The multiple arc sections include a first arc segment with a radius R1, a second arc segment with a radius R2, a third arc segment with a radius R3, and a fourth arc segment with a radius R4 which are connected in sequence.

9. The degradable vascular stent according to claim 8, characterized in that: The radius R2 of the second arc segment is greater than the radius R1 of the first arc segment, and the radius R3 of the third arc segment is greater than the radius R4 of the fourth arc segment.

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