CN117257536A - Vascular stent - Google Patents

Abstract

The invention provides a vascular stent, which comprises a stent main body made of a wire material in a braiding way, wherein an anchoring part is formed in a part area of at least one wire material, and the anchoring part comprises a bending part and a non-bending part; the outer surface area per unit length of the folded portion is larger than the outer surface area per unit length of the non-folded portion in the knitting direction; the anchoring portion is used to increase the area of the stent when it contacts the vessel wall. The vascular stent obtains stronger anchoring capability by utilizing the anchoring part, so that the vascular stent can be anchored at an expected position in a blood vessel well, the displacement risk of the vascular stent is reduced, and other complications and damages to the blood vessel wall caused by the displacement of the vascular stent can be avoided.

Description

Vascular stent

Technical Field

The invention relates to the technical field of medical equipment, in particular to a vascular stent.

Background

For interventional treatment of human blood vessels, such as intracranial blood vessels, stents are often used as the primary or auxiliary instrument in the treatment of conditions such as vascular stenosis, vascular embolism, aneurysms, etc. In order to enable the stent to smoothly pass through a tortuous blood vessel and reach a focus part, the stent can be woven by a metal wire, so that the stent has better compliance and flexibility.

However, the stent made of the metal wire braiding has poor radial supporting force and poor fixing capability of the end part of the stent in the blood vessel, which often causes the stent to shift due to insufficient anchoring capability in the blood vessel (especially in the bent section of the blood vessel), thereby being more likely to cause the extension of operation time and the replacement of instruments, even possibly causing medical accidents such as operation failure, unexpected damage of the blood vessel and the like, increasing uncomfortable feeling in the operation process of the patient and even directly endangering the life safety of the patient.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention aims to provide a vascular stent which can be well anchored at an expected position in a vascular wall, reduce the displacement risk of the vascular stent and avoid other complications of the vascular stent caused by displacement.

In order to achieve the above object, the present invention provides a vascular stent comprising a stent body made of a wire woven, at least one of partial regions of the wire forming an anchoring portion, the anchoring portion comprising a bent portion and a non-bent portion; the outer surface area per unit length of the folded portion is larger than the outer surface area per unit length of the non-folded portion in the knitting direction; the anchoring portion is used to increase the area of the stent when it contacts the vessel wall.

Optionally, at least a portion of the wire is bent back at least one end of the stent body to form a closed end, at least a partial region of the closed end forming the anchoring portion.

Optionally, at least a portion of the wire is bent back at both ends of the stent body to form the closed ends, at least a partial region of each of the closed ends forming the anchoring portion.

Optionally, an included angle between an initial extending direction of the wire in the anchoring portion and an axis of the stent body is [90 °,180 ° ].

Optionally, the anchoring portion comprises at least one arched curved structure, at least one of the arched curved structures being for contacting a vessel wall.

Optionally, at least one of the arched curved structures comprises a spring segment formed by helically winding the wire, at least one of the arched curved structures being provided with the spring segment on at least one side of the apex.

Optionally, the diameter of the spring section in the initial state is 0.001inch to 1.0inch, and/or the radius of curvature of at least one of the arched curved structures in the initial state is 1mm to 50mm, and/or the ratio of the length of the spring section in the initial state to the length of at least one of the arched curved structures in the initial state is 1: 100-1:1.

Optionally, at least one of the arched curved structures comprises a roughened section formed by surface treatment of the wire, at least one of the arched curved structures being provided with the roughened section on at least one side of the apex.

Optionally, the roughness of the rough segment is 0.8um to 100um, and/or the radius of curvature of at least one of the arched curved structures in the initial state is 0.5mm to 50mm, and/or the ratio of the rough segment to the outer surface area of at least one of the arched curved structures in the initial state is 1: 100-1:1.

Optionally, at least one of the arched curved structures comprises a deformed segment formed by pressing the wire, the deformed segment increasing in width in a first direction and decreasing in thickness in a second direction.

Optionally, the deformed segment has a width in the first direction that increases by no more than 90% and no less than 10% of the original width of the deformed segment; the thickness of the deformed segment in the second direction is reduced by a proportion of not more than 90% and not less than 10% of the original thickness of the deformed segment.

Optionally, the ratio of the width of the cross section of the wire in the first direction to the thickness of the wire in the second direction is 10:1 to 1:1, and/or the ratio of the length of the deformed section in the initial state to the length of at least one arched curved structure in the initial state is 1: 100-1:1.

Optionally, the curvature radius of the closed end in the initial state is 0.5 mm-20 mm.

Optionally, the wire is bent back in the same plane and kinked with itself to form the anchor.

Optionally, the wire is twisted at least twice in a staggered manner to form the lasso-shaped anchoring portion, wherein the wire is bent first and then twisted with itself in a staggered manner, and the wire is bent at least multiple times, and a staggered twist is formed between every two adjacent bends.

Optionally, the wire is bent and kinked in at least two different directions multiple times to form the mesh-like anchoring portion.

Optionally, the wire is bent multiple times in different planes to form the anchor.

Optionally, the wires are bent in a first plane and a second plane to form the anchoring portion, the first plane and the axis of the bracket main body form a first angle, and the second plane and the first plane form a second angle.

Optionally, a first angle between the first plane and the axis of the stent body is [90 °,180 ° ], and/or a second angle between the first plane and the second plane is (0, 180 ° ].

Optionally, the wire is bent outwards to form the anchoring portion with a sliding surface, and an included angle between the sliding surface of the anchoring portion and the axis of the bracket main body is [90 degrees, 180 degrees ].

Optionally, the minimum side length of the wire is 0.005 inch-1.0 inch.

The invention provides a vascular stent, which can increase the contact area of the vascular stent and the vascular wall and the anchoring capability of the vascular stent on the vascular wall through the arrangement of an anchoring part, so that the vascular stent can be anchored at an expected position in a blood vessel well, the displacement risk of the vascular stent is reduced, and other complications caused by the displacement of the vascular stent and the damage to the vascular wall can be avoided.

Drawings

FIG. 1 is a schematic view of a stent in accordance with a preferred embodiment of the present invention;

FIG. 2 is a schematic view of a first arch-shaped curved structure of an anchoring portion according to a preferred embodiment of the present invention;

FIG. 3 is a schematic view of a second arched curved structure of an anchor portion according to a preferred embodiment of the present invention;

FIG. 4 is a schematic view showing a structure in which an anchoring portion is curved in a third arch shape according to a first preferred embodiment of the present invention;

FIG. 5 is a schematic view showing the structure of an anchor portion according to a second preferred embodiment of the present invention;

FIG. 6 is a schematic view showing the structure of an anchor portion according to another preferred embodiment of the second embodiment of the present invention;

FIG. 7 is a schematic view showing the structure of an anchor portion in a preferred embodiment of the third embodiment of the present invention;

fig. 8 is a schematic structural view of an anchoring portion in another preferred embodiment of the third embodiment of the present invention.

In the figure: a holder main body 1; a wire 10; a closed end 11; anchoring portions 2, 3, 4; a first arched, curved structure 21; a spring section 211; a second arched, curved structure 22; a rough segment 221; a smoothing section 222; a third arched, curved structure 23; a deformation section 231; a first staggered kink site 31; a second staggered kink site 32; a third staggered kink site 33; a fourth staggered kink site 34; a first plane 41; a second plane 42; a slide surface 43; a first bending section 431; a second bending section 432.

Detailed Description

The invention is described in further detail below with reference to the drawings and the specific examples. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.

The terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counter-clockwise," "axial," "radial," "circumferential," etc. refer to an orientation or positional relationship based on that shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention. The term "proximal" generally refers to an end proximal to the vascular stent operator; "distal" is the end opposite "proximal" and generally refers to the end that is first implanted in a patient.

Fig. 1 is a schematic structural view of a stent according to a preferred embodiment of the present invention.

As shown in fig. 1, a preferred embodiment of the present invention provides a vascular stent comprising a stent body 1 woven from wires 10, wherein a portion of at least one wire 10 forms an anchor portion (e.g., region a in fig. 1) which is further divided into a bent portion and a non-bent portion, and an outer surface area per unit length (in a weaving direction) of the bent portion is larger than an outer surface area per unit length (in a weaving direction) of the non-bent portion. Another partial region of at least one wire 10 forms the stent body, i.e., the non-anchoring portion (e.g., region b in fig. 1). The anchoring portion is used for increasing the area of the vascular stent when the vascular stent is in contact with the vascular wall. In the present application, the outer surface of the stent is used for contacting the wall of the blood vessel, and the stent contacts the wall of the blood vessel mainly through the anchoring portion, and the anchoring portion further comprises a bending portion and a non-bending portion, wherein the bending portion contacts the wall of the blood vessel mainly. In the knitting direction, increasing the outer surface area per unit length of the bent portion can improve the contact area with the blood vessel wall, and further improve the anchoring performance.

It should be further understood that the anchoring portion in the present application is directly made of the wire 10, for example, the surface roughness of the wire 10 is treated to form protrusions on the surface of the wire 10, so as to increase the surface area of the wire 10, or the wire 10 is subjected to processes such as bending, winding, knotting, etc. to change the shape of the wire 10, so as to increase the surface area of the wire 10, which is not limited to this example, but may be other ways of increasing the surface area of the wire 10. In addition, in the actual manufacturing process, after the wire 10 is wound into the anchoring portion and the stent body 1, the stent may be subjected to a shaping treatment (e.g., a heat treatment shaping), so that a shape-stable stent structure may be obtained.

After the vascular stent provided by the embodiment is implanted into a blood vessel, the friction force between the vascular stent and the vascular wall can be increased by utilizing the anchoring part, so that the impact of blood flow on the vascular stent can be resisted, the anchoring capacity of the vascular stent on the vascular wall is increased, the vascular stent can be better anchored at an expected position in the blood vessel, the displacement risk of the vascular stent is reduced, and other complications caused by the displacement of the vascular stent and the damage to the vascular wall can be avoided.

It should be understood that the present application is not limited to the number of wires 10 used to make the anchor. The anchoring portion may be made from one or more wires by a predetermined process, preferably including bending. The location of the anchoring portion is not limited in this application, and the anchoring portion may be disposed at any location where the stent contacts the vessel wall. The structure of the anchoring portion is not limited in the present application, and the anchoring portion may be provided as any structure capable of increasing the contact area of the stent and the vessel wall as needed. The number of the anchoring portions is not limited, and may be set according to the type and shape of the stent.

In an embodiment, the anchoring portion may be provided at the middle of the stent body 1, in which case the stent may increase friction with the vessel wall by the anchoring portion. The term "middle portion of the stent body 1" herein should not be interpreted narrowly as an absolute middle position, but as a portion between the proximal and distal ends of the stent body 1.

In another embodiment, the anchoring portion is provided at an end of the stent body 1, such as a proximal end, a distal end, or both, at which time displacement of the stent may be avoided by anchoring the end of the stent body 1.

In other embodiments, the anchoring portion is provided at both the end portion of the stent body 1 and the middle portion of the stent body 1.

As a preferred embodiment, the number of the anchoring portions is plural, and the plural anchoring portions may be provided at the middle portion and/or the end portion of the stent.

The structure of the wire 10 is not limited in this application, and the cross-sectional shape of the wire 10 includes, but is not limited to, circular, square, oval, trapezoidal, and the like.

For better strength and toughness of the vascular stent, the minimum edge length of the wire 10 is preferably 0.005inch to 1.0inch. It should be understood that when the wire 10 is square in configuration, the minimum side length refers to the length of the shortest side in cross section of the wire 10; when the wire 10 is of a circular configuration, the minimum side length refers to the length of the diameter in the wire 10; when the wire 10 is oval or otherwise shaped, the minimum side length refers to the shortest distance between any two points in the cross section of the wire 10.

The material of the wire 10 is not limited in this application, and the material of the wire 10 may be one or a combination of several of stainless steel, nickel-titanium alloy, cobalt and cobalt alloy, platinum and platinum alloy, tungsten and tungsten alloy, and magnesium alloy. The material of the wire 10 may also be a medical polymer material. Further, at least a portion of the material of the wire 10 includes a metallic developing material.

With continued reference to fig. 1, in one embodiment, at least a portion of the wire 10 is bent back at least one end of the stent body 1 to form a closed end 11, with at least a portion of the area of the closed end 11 forming an anchor. The closed end 11 herein is understood to mean a closed structure provided at an end position of at least one end of the holder body 1 on the axis. So configured, on the one hand, anchoring portions of different structures and different degrees of complexity may be provided at the end of the stent body 1; on the other hand, the vascular stent can be made to have better compliance in the blood vessel, so that the vascular stent can be moved to a desired position in the blood vessel more easily.

In a preferred embodiment, at least a portion of the wire 10 is bent back at both ends of the stent body 1 to form the closed end 11, the bent section forms a bent portion, and two extending structures connected to the bent section are non-bent portions, and the bent portion and the non-bent portions together form the anchoring portion. The number of the anchoring parts is plural, and at least one anchoring part is provided at both the proximal end and the distal end of the stent body 1 along the axis, so that the anchoring ability of the stent can be further increased, thereby preventing displacement of the stent in the blood vessel.

Preferably, the initial extending direction of the wire 10 in the anchoring portion and the axis of the stent body 1 form an included angle of 90 degrees and 180 degrees, so that the anchoring portion does not influence or interfere with the contact between the stent body 1 and the vessel wall when contacting the vessel wall, thereby ensuring the therapeutic effect of the vessel stent; on the other hand, because the pressure which the vessel wall can bear is limited, the included angle between the anchoring part and the axis of the stent main body 1 is not required to be too small, so as to avoid the injury of the vessel wall caused by the vessel stent. Defining the direction a in fig. 1 as the positive direction of the axis of the stent body 1, it should be understood that the angle between the initial extending direction of the wire 10 and the axis of the stent body 1in the present application refers to the angle between the initial extending direction of the wire 10 in the anchoring portion and the positive direction of the axis of the stent body 1 (i.e., the direction a in fig. 1). It should also be understood that the initial direction of extension of the wire 10 in the anchoring portion refers to the direction of extension of the wire 10 in the anchoring portion at the junction of the anchoring portion and the non-anchor portion forming region in the closed end 11, i.e. the direction of extension of the wire 10 in the anchoring portion before the first bending during the formation of the anchoring portion, i.e. the direction of extension of the non-bent portion in the anchoring portion, i.e. the braiding direction of the wire.

For a clearer explanation of the vascular stent provided by the present invention, the following specific preferred embodiments are listed for further explanation, but the following explanation is not to be taken as a limitation of the structure of the anchoring portion in the present application.

Example 1

Referring to fig. 2 to 4, in combination with fig. 1, in a vascular stent according to a first embodiment of the present invention, the vascular stent includes a stent body 1 woven from wires 10, wherein during the weaving of the wires 10 to form the stent body 1, at least a part of the wires 10 further form an anchor portion 2 in some regions, wherein the anchor portion 2 includes a bent portion and a non-bent portion. The anchoring portion 2 can be used to enhance the anchoring ability of the stent and prevent the stent from being displaced in the vessel.

In this embodiment, the anchoring portion 2 comprises at least one arched curved structure for contacting the vessel wall. Since the wire 10 may form a plurality of arched bent structures at the middle or end portions during the braiding of the stent body 1, the anchoring portions may be provided at the positions of the arched bent structures, so that the structure of the stent body 1 remains unchanged and the arrangement of the anchoring portions may be facilitated. That is, the anchor portion 2 is provided at the bending portion of the wire 10.

Referring to fig. 2, in some embodiments, the anchoring portion includes at least one first arched curved structure 21, and the first arched curved structure 21 includes a spring segment 211 formed by spirally winding the wire 10, i.e., a bent portion c, and non-bent portions d located at both sides of the bent portion c are also identified. The spring sections 211 are preferably in the same plane, so that the plane of the first arched curved structure 21 is in contact with the vessel wall; in other embodiments, the spring segments 211 may not be disposed in the same plane, and any position of the spring segments 211 may be in contact with the vessel wall. So constructed, on the one hand, the spring section 211 can increase the contact area between the stent and the vessel wall, and on the other hand, since the spring section 211 has elastic force, the spring section 211 contacting the vessel wall can apply tension to the vessel wall to limit the anchoring portion 2 on the vessel wall, thereby realizing good anchoring of the stent on the vessel wall and good anchoring effect.

Further, the first arched, curved structure 21 may be provided with a spring section 211 on at least one side of the apex. The position of the spring section 211 on the first arched curved structure 21 is not limited in the present application, and the spring section 211 may be symmetrically or asymmetrically disposed with respect to the apex of the first arched curved structure 21, preferably symmetrically disposed, so that the contact area between the spring section 211 and the blood vessel wall is larger and the tension on the blood vessel wall is larger. It should be understood that, in the present application, the two sides of the apex of the first arched curved structure 21 refer to the left side (i.e., the L side in fig. 2) and the right side (i.e., the R side in fig. 2) of the first arched curved structure 21 with respect to the apex thereof in the plane formed by the first arched structure 21; likewise, at least one side of the apex of the first arched curved structure 21 refers to the left or right side of the first arched curved structure 21 relative to its apex.

In order to match the dimensions of the anchoring portion 2 to the diameters of the stent body 1 and the vessel wall while ensuring sufficient strength, toughness and tension of the spring section 211, the diameter of the spring section 211 in the initial state is preferably 0.001inch to 1inch, and the radius of curvature of the first arched bent structure 21 in the initial state is preferably 1mm to 50mm. Meanwhile, in order to provide a better anchoring effect for the stent, the ratio of the length of the spring section 211 in the initial state to the length of the first arched curved structure 21 in the initial state is preferably 1: 100-1:1. It should be appreciated that the initial state of the spring section 211 and the first arched curved structure 21 both refer to a state in which the spring section 211 is in a state in which only its own weight is acting, i.e. a state in which the spring section 211 is not under compression or tension.

In an embodiment, the surface of the spring section 211 contacting the vessel wall may be provided with an uneven surface (e.g., a corrugated surface) to further increase the contact area and friction between the spring section 211 and the vessel wall. In another embodiment, the surface of the spring section 211 contacting the vessel wall may also be provided as a smooth surface. It should be understood that the uneven surface herein means that the surface of the spring section 211 contacting the vessel wall is uneven, and that the smooth surface herein means that the surface of the spring section 211 contacting the vessel wall is substantially smooth.

Referring to fig. 3, in other embodiments, the anchoring portion includes a second arched curved structure 22, where the second arched curved structure 22 includes a roughened section 221 formed by the surface treatment of the wire 10, i.e., a bent portion c, and non-bent portions d located on both sides of the bent portion c are identified, and the second arched curved structure 22 is provided with the roughened section 221 on at least one side of the apex. The roughened segments 221 are preferably in the same plane so that the plane of the second arched curved structure 22 is in contact with the vessel wall; in other embodiments, the rough segments 221 may not be disposed in the same plane, and any position of the rough segments 221 may contact the vessel wall. By this arrangement, the surface roughness of the wire 10 can be increased to increase the contact area and friction between the anchor portion 2 and the vessel wall, thereby increasing the anchoring ability of the stent on the vessel.

Specifically, since the wire 10 of the braided vascular stent is generally made of a surface polished or oxidized material, in order to make the surface of the wire 10 have a large roughness, the surface of the wire 10 may be treated by micro-arc oxidation, grinding, sand blasting, shot blasting, pickling and etching to increase the surface roughness, so as to form the roughened section 221, so the treatment mode of the surface of the wire 10 is not limited in this application. In the present embodiment, in order to provide a large friction force between the anchor portion 2 and the vessel wall, the roughness Ra of the surface of the roughened portion 211 is preferably 0.8um to 100um.

The position of the roughened segment 221 on the anchor portion 2 is not limited in the present application, as long as the roughened segment 221 is provided on at least one side of the apex of the second arched curved structure 22. The rough segments 221 may be symmetrically or asymmetrically disposed with respect to the apex of the second arched curved structure 22, preferably symmetrically disposed, such that the rough segments 221 have a relatively high friction.

In order to match the dimensions of the anchoring portion 2 to the diameters of the stent body 1 and the vessel wall while ensuring sufficient friction of the roughened section 221, the radius of curvature of the second arched curved structure 22 in the initial state is preferably 0.5mm to 50mm. Meanwhile, in order to provide a better anchoring effect for the stent, the ratio of the area of the roughened section 221 to the area of the second arched curved structure 22 in the initial state is 1: 100-1:1.

With continued reference to fig. 3, the second arched curved structure 22 may also include a smooth segment 222, where the rough segment 221 has a roughness greater than the roughness of the smooth segment 222. The smooth section 222 may be formed by the wire 10 without surface treatment, and the rough section 221 is only required to be arranged on a partial area of the second arched bending structure 22, so that the vascular stent has better anchoring capability. It should be understood that the initial state of the second arched curved structure 22 also refers to a state when the second arched curved structure 22 is not subjected to an external force other than its own weight, i.e., a state when the second arched curved structure 22 is not subjected to compression or tension.

Further, when the surface treatment is performed on the wire 10 on the anchor portion 2, the wire 10 may be previously processed on the wire 10 before the wire 10 is woven into the stent body 1, or the wire 10 may be processed after the wire 10 is woven into the stent body 1 to form the roughened section 221 on the anchor portion 2.

Referring to fig. 4, in still other embodiments, the anchoring portion includes at least one third arched curved structure 23, where the third arched curved structure 23 includes a deformed segment 231 formed by pressing the wire 10, i.e., a bent portion c, and non-bent portions d located on both sides of the bent portion c are also identified. The deformed segment 231 increases in width in a first direction B and decreases in thickness in a second direction (not shown), the first direction B being perpendicular to the second direction. In use, the third arched, curved structure 23 contacts the vessel wall in the first direction B, which increases the friction between the anchoring portion 2 and the vessel wall by increasing the contact area of the wire 10 with the vessel wall, thereby increasing the anchoring capacity of the stent on the vessel wall.

The position of the deformation section 231 on the third arched curved structure 23 is not limited in the present application, as long as the deformation section 231 is disposed at least on one side of the apex of the third arched curved structure 23. Further, the deformation segments 231 may be symmetrically or asymmetrically disposed with respect to the apex of the third arched curved structure 23, preferably symmetrically disposed, so that the deformation segments 231 have a larger contact area with the vessel wall.

The present application is not limited to the pressing method of the wire 10, and the pressing method of the wire 10 includes, but is not limited to, hot and cold extrusion, hot and cold rolling, and hot and cold forging. After the wire 10 is pressed, the cross-sectional shape of the wire 10 includes, but is not limited to, square, oval, or trapezoidal.

Further, to ensure both strength and anchoring capability of the wire 10, the cross-section of the deformed segment 231 is increased in width by a proportion of not more than 90% of the original width of the deformed segment 231 and not less than 10% of the original length of the deformed segment 231 (i.e., the width of the wire 10 in the first direction B is increased by 10% -90%), and likewise, the thickness of the deformed segment 231 is reduced in thickness by a proportion of not more than 90% of the original thickness of the deformed segment 231 and not less than 10% of the original thickness of the deformed segment 231 (i.e., the thickness of the wire 10 in the second direction is reduced by 10% -90%). Preferably, the ratio of the width of the cross section of the wire 10 in the first direction B to the thickness in the second direction is 10:1 to 1:1.

In order to provide a better anchoring effect for the stent, the ratio of the length of the deformed segment 231 in the initial state to the length of the third arched curved structure 23 in the initial state is 1: 100-1:1. It should be understood that the initial state of the deformed segment 231 and the third arched structure 22 refers to a state when the deformed segment 231 is not subjected to an external force other than its own weight, i.e., a state when the deformed segment 231 is not subjected to compression or tension.

Example two

Referring to fig. 5 and 6, and referring to fig. 1, in a vascular stent according to a second embodiment of the present invention, the vascular stent includes a stent body 1 woven from wires 10, wherein during the weaving of the wires 10 to form the stent body 1, at least some of the wires 10 further form anchoring portions 3 in certain regions. As shown, the anchor portion 3 includes a bent portion c and a non-bent portion d. The anchoring portion 3 can be used to enhance the anchoring ability of the stent and prevent the stent from being displaced in the vessel.

In this embodiment, the anchoring portion 3 is formed by bending and winding the wire 10 in the same plane and twisting the wire in a staggered manner, and the anchoring portion 3 is disposed on the closed end 11 of the vascular stent, that is, the anchoring portion 3 is disposed on at least one end, such as the proximal end and/or the distal end, of the stent body 1 along the axis.

In order to match the size of the anchor portion 3 to the diameters of the stent main body 1 and the vessel wall and to enable the wire 10 to form the anchor portion 3, the radius of curvature of each bending of the wire 10 is preferably 0.5mm to 20mm when the winding direction is changed.

Referring to fig. 5, in some embodiments, the wires 10 are twisted at least twice in the same plane to form a lasso-shaped bending portion c, where the bending portion c is understood to be a bending portion of the end of the entire anchoring portion starting from the weaving direction of the wires, and the bending portion c is understood to be a combined structure formed by twisting the wires in multiple times. Specifically, the wire 10 is bent first and then is twisted with itself in a staggered manner, and the wire 10 is bent at least a plurality of times, and a staggered twist is formed between every two adjacent bends; thus, the anchoring portion 3 is able to contact the vessel wall in the curved plane of the wire 10. By means of the arrangement, on one hand, the contact area between the vascular stent and the vascular wall can be increased through repeated bending and staggered kinking, and on the other hand, the lasso-shaped anchoring part 3 can apply additional radial force to the vascular wall, so that the stent main body 1 can be well limited on the vascular wall, and good anchoring of the vascular stent on the vascular wall is achieved. It should be understood that the interlaced twisting is a structure formed by interlacing the wire 10 with itself and then changing the winding direction.

With continued reference to fig. 5, in this embodiment, the wire 10 is at least once cross-kinked on either side of the apex of the lasso-shaped anchor portion 3, and the lasso-shaped anchor portion 3 includes a first cross-kink site 31 and a second cross-kink site 32. Specifically, the lasso-shaped anchoring portion 3 is a structure in which the wire 10 changes the winding direction three times in the same plane, and changes the winding direction twice again in the plane after the first interlacing and twisting position 31 is interlaced and twisted with itself, and is formed by interlacing and twisting the wire 10 with itself again in the second interlacing and twisting position 32, and the wire 10 extends in the direction substantially parallel to the axis after each interlacing and twisting, so that on one hand, the contacted vessel wall can be anchored more strongly by the extending direction consistent with the wire, and on the other hand, the friction force in the conveying process can not be excessively increased by the extending direction consistent with the wire.

The bending direction and the number of times of the interlacing kinks of the wire 10 are not particularly limited in this application, and the bending direction and the number of times of the interlacing kinks of the wire 10 may be set as needed. In order to facilitate the winding of the wire 10 in the anchoring portion 3 and the braiding of the stent body 1, the wire 10 in the anchoring portion 3 forms at least two staggered kinks with itself in the same plane, and the larger the number of times of staggered kinks of the wire 10 is, the larger the contact area between the anchoring portion 3 and the vessel wall is, and the better the anchoring effect of the vessel stent is.

Referring to fig. 6, in other embodiments, the wire 10 is bent in at least two different directions multiple times in the same plane and kinked in a staggered manner to form a web-like bend c that contacts the vessel wall in the plane of bending of the wire 10. The bending part c is understood to be the bending part of the end part of the whole anchoring part starting from the weaving direction of the wire, and the bending part c is understood to be the combined structure formed by twisting the wire for a plurality of times. The mesh-shaped anchoring portion 3 can increase the contact area between the vascular stent and the vascular wall on one hand, and the mesh-shaped anchoring portion 3 can apply additional radial force to the vascular wall on the other hand, so that the stent main body 1 can be well limited on the vascular wall, and good anchoring of the vascular stent on the vascular wall is realized.

In this embodiment, the mesh-like anchoring portion 3 includes a third staggered kink site 33 and a fourth staggered kink site 34. Specifically, the mesh-shaped anchoring portion 3 is formed by bending the wire 10 in the initial extending direction thereof to form an arch, winding the wire on the arch-shaped bending structure a plurality of times to form a plurality of third staggered kink positions 33, and then twisting the wire with the wire at the fourth staggered kink positions 34 and passing through the winding positions. At this time, the mesh structure of the anchor portion 3 can be increased in density by increasing the number of bends and the number of staggered kinks of the wire 10, thereby further increasing the contact area of the anchor portion 3 with the vessel wall.

The initial extending direction and the winding direction of the wire 10 are not particularly limited, and any angle may be formed between the initial extending direction and the winding direction of the wire 10, and it is preferable that the initial extending direction and the winding direction of the wire 10 are perpendicular. In other embodiments, the wires 10 in the anchoring portion 3 may be alternatively twisted to form the net-shaped anchoring portion 3, for example, the wires 10 may be bent into a structure group parallel to the initial extending direction, and then the wires 10 are wound around the structure group to form the net-shaped anchoring portion 3.

Referring to fig. 5 and 6, the direction of extension of the wire 10 after each interlaced kink or the direction of winding after bending is angled, preferably nearly parallel or perpendicular, to the direction of extension of the woven extension of the wire or the non-bent portion.

Example III

Referring to fig. 7 and 8, in a vascular stent according to a third embodiment of the present invention, the vascular stent includes a stent body 1 woven from wires 10, wherein the wires 10 further form anchor portions 4 in certain regions of at least part of the wires 10 during the weaving to form the stent body 1. The anchoring portion 4 may be used to enhance the anchoring ability of the stent and to prevent the stent from shifting in the vessel.

In this embodiment, the wire 10 is bent in different planes to form the anchoring portion 4, the anchoring portion 4 being arranged on the closed end 11 of the vascular stent, i.e. the anchoring portion 4 is arranged at least one end of the stent body 1 along the axis, such as the proximal and/or distal end.

In order to match the size of the anchoring portion 4 with the diameters of the stent main body 1 and the vessel wall and to enable the wire 10 to form the anchoring portion 4 and to enable the anchoring portion 4 to have a good anchoring ability, the radius of curvature of each bending of the wire 10 is preferably 0.5mm to 20mm when the winding direction is changed.

Referring to fig. 7, in an embodiment, the wire 10 is bent in the first plane 41 and the second plane 42, respectively, to form a bending portion c, which is understood to be a bending portion of the entire end of the anchoring portion starting in the weaving direction of the wire, and the bending portion c is understood to be a combined structure formed by the two planes. The first plane 41 forms a first angle θ1 with the axis of the bracket body 1, and the second plane 42 forms a second angle θ2 with the first plane 41. So arranged, on the one hand, when one plane (the first plane 41 or the second plane 42) is contacted with the vessel wall, the contact area between the vessel stent and the vessel wall is increased; on the other hand, when the first plane 41 is in contact with the vessel wall, the anchoring portion 4 may also exert additional tension on the vessel wall, thereby achieving good anchoring of the stent on the vessel wall.

Specifically, the second plane 42 may be parallel to the axis of the bracket body 1, or may be disposed at an angle with respect to the axis of the bracket body 1. The first plane 41 is for contacting the vessel wall to apply tension to the vessel wall when the second plane 42 is parallel to the axis of the stent body 1; when the second plane 42 is at an angle to the axis of the stent body 1, both the first plane 41 and the second plane 42 may be used to contact the vessel wall to apply tension to the vessel wall.

In the present embodiment, the anchoring portion 4 is formed by bending the wire 10 a plurality of times in a plane forming a first angle θ1 with the axis of the stent body 1 to form a first plane 41, and then bending a plurality of times in a plane forming a second angle θ2 with the first plane 41 to form a second plane 42, and finally forming the closed anchoring portion 4 at the closed end 11 of the stent body 1.

Further, an anchor portion 4 is provided at least one end of the axis of the holder main body 1. Preferably, the number of the anchor portions 4 is plural and is provided at the proximal and distal ends of the axis of the stent body 1.

With continued reference to fig. 7, the first angle θ1 between the first plane 41 and the axis of the stent body 1 is preferably [90 °,180 °), so that the anchoring portion 4 does not affect or interfere with the contact between the stent and the vessel wall when contacting the vessel wall, thereby ensuring the therapeutic effect of the stent. The second angle θ2 between the first plane 41 and the second plane 42 is preferably (0 °,180 ° ], and the anchor portion 4 can apply a certain tension to the vessel wall.

The structure of the included angle formed by the two planes in fig. 7 utilizes the triangle stabilization principle, so that the structure of the anchoring part is more stable and does not move mutually any more, and the anchoring performance is further improved.

Referring to fig. 8, in another embodiment, the wire 10 is bent outwards to form an anchoring portion 4 with a sliding surface 43, and the sliding surface 43 of the anchoring portion 4 and the axis of the stent body 1 form an included angle of [90 °,180 ° ], so that the sliding surface 43 of the anchoring portion 4 contacts the vessel wall to increase the contact area between the vessel stent and the vessel wall; and the ramp surface 43 may also exert a certain tension on the vessel wall when in contact therewith, thereby achieving a good anchoring of the stent on the vessel wall.

Preferably, the anchoring portion 4 may be arranged in a symmetrical configuration, i.e. the ramp surface 43 is arranged in a symmetrical configuration, which may enable the anchoring portion 4 to more fully contact the vessel wall.

In a preferred embodiment, the ramp surface 43 may be provided in an arched configuration, i.e. forming a bend c. A connection is provided between the land surface 43 and the area of the wire 10 where the anchor 4 is not formed, which enables smooth connection of the land surface 43 to the area of the wire 10 where the anchor 4 is not formed.

As shown in fig. 8, in the present embodiment, the anchoring portion 4 is a symmetrical structure formed by bending the wire 10 multiple times, wherein the wire 10 includes a first bending section 431 and a second bending section 432 on both sides of the vertex of the anchoring portion 4, the first bending sections 431 on both sides of the vertex of the anchoring portion 4 form a connecting portion, and the second bending sections 432 are bent and wound back to form the sliding surface 43. In order to ensure that the anchoring portion 4 is sufficiently in contact with the vessel wall and that a certain tension is applied to the vessel wall, the third angle θ3 between the first bending section 431 and the axis of the stent body 1 is [90 °,180 °. In addition, the angle between the first bending section 431 and the second bending section 432 may be set according to the amount of tension required by the anchoring portion 4.

It should be appreciated that the structure of the anchor portion in the present invention may be any one or a combination of the above-described embodiments one to three. Therefore, the structure of the anchoring part can be flexibly designed according to the requirement, so that the larger contact area is ensured when the anchoring part is contacted with the vessel wall, and the anchoring capability of the vessel stent on the vessel wall can be improved.

In summary, the vascular stent provided by the invention can increase the contact area between the vascular stent and the vascular wall and the anchoring capability of the vascular stent on the vascular wall through the arrangement of the anchoring part, so that the vascular stent can be anchored at the expected position in the blood vessel well, the displacement risk of the vascular stent is reduced, and other complications caused by the displacement of the vascular stent and the damage to the vascular wall can be avoided.

The above description is only illustrative of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, and any alterations and modifications made by those skilled in the art based on the above disclosure shall fall within the scope of the present invention.

Claims (21)

1. A vascular stent, comprising a stent body woven from wires, at least one of the wires having a portion of its area forming an anchor portion, the anchor portion comprising a bent portion and a non-bent portion;

the outer surface area per unit length of the folded portion is larger than the outer surface area per unit length of the non-folded portion in the knitting direction;

the anchoring portion is used to increase the area of the stent when it contacts the vessel wall.

2. The vascular stent of claim 1, wherein at least a portion of the wire is bent back at least one end of the stent body to form a closed end, at least a portion of the area of the closed end forming the anchoring portion.

3. The vascular stent of claim 2, wherein at least a portion of the wire is bent back at both ends of the stent body to form the closed ends, at least a portion of each of the closed ends forming the anchor.

4. The vascular stent of claim 2, wherein an angle between an initial extension direction of the wire in the anchoring portion and an axis of the stent body is [90 °,180 ° ].

5. The vascular stent of any of claims 1-4, wherein the anchoring portion includes at least one arcuate curved structure, at least one of the arcuate curved structures being configured to contact a vessel wall.

6. The vascular stent of claim 5, wherein at least one of the arcuate curved structures comprises a spring segment formed by helically winding the wire, the at least one arcuate curved structure being provided with the spring segment on at least one side of the apex.

7. The vascular stent of claim 6, wherein the spring segments have a diameter of 0.001inch to 1.0inch in an initial state, and/or wherein at least one of the arcuate curved structures has a radius of curvature of 1mm to 50mm in an initial state, and/or wherein the ratio of the length of the spring segments in an initial state to the length of at least one of the arcuate curved structures in an initial state is 1: 100-1:1.

8. The vascular stent of claim 5, wherein at least one of the arcuate curved structures comprises a roughened segment formed by surface treatment of the wire, the roughened segment being disposed on at least one side of the apex by at least one of the arcuate curved structures.

9. Vascular stent according to claim 8, wherein the roughness of the roughened section is between 0.8um and 100um, and/or wherein the radius of curvature of at least one of the arched curved structures in the initial state is between 0.5mm and 50mm, and/or wherein the ratio of the surface area of the roughened section to the surface area of at least one of the arched curved structures in the initial state is 1: 100-1:1.

10. The vascular stent of claim 5, wherein at least one of the arcuate curved structures includes a deformed segment formed from the wire by compression, the deformed segment having an increased width in a first direction and a decreased thickness in a second direction.

11. The vascular stent of claim 10, wherein the deformed segment increases in width in the first direction by no more than 90% and no less than 10% of the original width of the deformed segment; the thickness of the deformed segment in the second direction is reduced by a proportion of not more than 90% and not less than 10% of the original thickness of the deformed segment.

12. The vascular stent of claim 10, wherein the ratio of the width of the cross section of the wire in the first direction to the thickness in the second direction is 10:1 to 1:1, and/or the ratio of the length of the deformed segment in the initial state to the length of at least one of the arched curved structures in the initial state is 1: 100-1:1.

13. A vascular stent as claimed in any one of claims 2 to 4, wherein the closed end has a radius of curvature in the initial state of from 0.5mm to 20mm.

14. The vascular stent of any of claims 2-4, wherein the wire is bent back in the same plane and kinked in-line with itself to form the anchor.

15. The vascular stent of claim 14, wherein the wire is twisted at least twice to form the anchor portion in the form of a lasso, wherein the wire is bent before being twisted with itself, and wherein the wire is bent at least a plurality of times to form a single twist between each adjacent two bends.

16. The vascular stent of claim 14, wherein the wire is bent in at least two different directions a plurality of times and kinked in a staggered manner to form the mesh-like anchoring portion.

17. The vascular stent of any of claims 2-4, wherein the wire is bent multiple times in different planes to form the anchor.

18. The vascular stent of claim 17, wherein the wires are bent in a first plane and a second plane, respectively, to form the anchoring portion, the first plane being at a first angle to the axis of the stent body, and the second plane being at a second angle to the first plane.

19. The vascular stent of claim 18, wherein a first angle between the first plane and the axis of the stent body is [90 °,180 ° ], and/or a second angle between the first plane and the second plane is (0, 180 ° ].

20. The vascular stent of claim 17, wherein the wire is bent outwardly to form the anchor portion having a ramp surface, the ramp surface of the anchor portion being at an angle [90 °,180 ° with respect to the axis of the stent body.

21. The vascular stent of claim 1, wherein the wire has a minimum side length of 0.005inch to 1.0inch.