Intracranial vascular stent

Abstract

The present invention provides an intracranial vascular stent, which relates to the technical field of medical devices. The intracranial vascular stent includes a middle part and an end part, the end part is connected to the two ends of the middle part, the middle part includes a plurality of corrugated support rings arranged along the axial direction, an S-shaped connecting rod is provided between adjacent corrugated support rings, the two ends of the S-shaped connecting rod are respectively connected to the crests and troughs of adjacent corrugated support rings, and a supporting part is provided on the S-shaped connecting rod, and when the corrugated support ring is compressed, the supporting part can resist the crests and / or troughs of the corrugated support ring. The intracranial vascular stent provided by the present invention forms two or more groups of pushing force transmission channels on an S-shaped connecting rod, and the pushing force can be more evenly transmitted to the corrugated support ring, reducing the risk of deformation of the stent caused by excessive local pushing force, significantly improving the pushing performance of the stent in the microcatheter, and solving the problems of the existing intracranial vascular stent being difficult to push and easy to bend.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to an intracranial vascular stent. Background Art

[0002] With the development of vascular interventional medical technology, minimally invasive interventional surgery has been widely used in the treatment of stroke, mainly including two types of intracranial vascular diseases: the first is the treatment of intracranial aneurysms, which often uses coil embolization, that is, using a microcatheter to deliver a coil to the aneurysm cavity, blocking the blood circulation in the aneurysm to form a thrombus and thus occluding the aneurysm. In order to prevent the coil from bulging out of the aneurysm cavity and causing vascular stenosis, doctors usually implant auxiliary stents to support the coil. The second is vascular stenosis caused by atherosclerosis, such as Figure 1 Doctors often insert a stent to widen the narrowed blood vessel to its desired diameter, thus restoring the blood supply.

[0003] Intracranial vascular stents are one of the main devices for the treatment of intracranial vascular diseases, but intracranial arterial vessels are usually very small. The diameter of the cerebral Willis circle ranges from 2.0 to 4.0 mm, the diameter of the cavernous sinus segment of the internal carotid artery is 2.5 to 5.5 mm, the diameter of the distal anterior circulation is 1.5 to 3.0 mm, and the diameter of the posterior circulation is 2.0 to 4.0 mm. In addition, there are many sharp bends in intracranial blood vessels with a small bending radius, which poses a huge challenge to the design of stents. First, the stent needs to be pushed to the lesion site through the tortuous microcatheter lumen, and the stent compressed in the microcatheter must have sufficient softness and pushability. Secondly, after the stent is released, the stent must have good wall adhesion and anti-bending properties in the tortuous lesion blood vessels.

[0004] Commonly used connecting rod shapes include "I" shape and curved shape. Figures 2-3 As shown, adjacent corrugated support rings are connected by a "I" connecting rod. Figure 2 The starting and ending points of the “I” connecting rod are the crests and troughs of the adjacent corrugated support rings. Figure 3 The starting and ending points of the “I” connecting rod are the wave crests of the adjacent corrugated support rings. Figure 2 In the direction of the middle arrow, a single connecting rod only forms one set of pushing force transmission channels. Since the stent is used for tortuous intracranial blood vessels, the number of connecting rods should not be too many for the overall flexibility of the stent, usually 3-5, so adjacent support rings generally have only 3-5 sets of pushing force transmission channels. In this way, when the stent is pushed, the force on the support ring is uneven, and when passing through a blood vessel with a large curvature, the required pushing force increases, and the stent is prone to local deformation.

[0005] The prior art patent CN115700113A provides a commonly used vascular stent design, which is used in Stryker's neuroform series products, such as Figure 2 As shown, the vascular stent is mainly composed of corrugated support rings and connecting rods, wherein the corrugated support rings are connected by straight-line connecting rods, and the crests and troughs of adjacent corrugated support rings are relatively non-rotationally misaligned.

[0006] When in the expanded state, the stent bends in the blood vessel, the inner curved side of the stent is compressed, and the relative peaks and troughs interfere with each other and cause warping; the outer curved side is stretched, and the straight-line connecting rod on the outer curved side cannot be stretched conformably. When the bending radius of the blood vessel is small, it is very easy to bend, causing the inner hole of the stent to become smaller, affecting blood flow.

[0007] In the compressed state, since the connecting rod is a straight-line connecting rod, one connecting rod can only form one set of push force transmission channels, and the push force cannot be evenly transmitted to the corrugated support ring. When the push force is large, the corrugated support ring or connecting rod of the stent may be deformed due to excessive local push force, thereby causing the stent to be stuck in the microcatheter.

[0008] The connecting rods of patent CN115700113A are distributed in a spiral shape throughout the stent. When the stent is released from the microcatheter, it rotates along the axis, inducing the microcatheter to rotate and thus become unstable in the blood vessel.

[0009] like Figure 4 As shown, adjacent corrugated support rings can also be connected by curved connecting rods. Figure 4 The connecting rod is U-shaped, and a single connecting rod only forms one set of pushing force transmission channels, which cannot solve the problem of uneven force during pushing.

[0010] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0011] The purpose of the present invention is to provide an intracranial vascular stent, which has good softness and pushability when compressed and transported in a microcatheter, and has good wall adhesion and resistance to bending and folding for tortuous diseased blood vessels when released and expanded, so as to solve the problems of existing intracranial vascular stents that are difficult to push and easy to fold.

[0012] In order to achieve the above object, the present invention provides the following technical solutions:

[0013] An intracranial vascular stent comprises a middle portion and end portions, wherein the end portions are connected to two ends of the middle portion, the middle portion comprises a plurality of corrugated support rings arranged along the axial direction, an S-shaped connecting rod is provided between adjacent corrugated support rings, the two ends of the S-shaped connecting rod are respectively connected to the crests and troughs of adjacent corrugated support rings, and a supporting portion is provided on the S-shaped connecting rod, and when the corrugated support ring is compressed, the supporting portion can resist the crests and / or troughs of the corrugated support ring.

[0014] Preferably, the S-shaped connecting rods are spaced apart in the circumferential direction, and the S-shaped connecting rods are arranged in a circular array around the axis of the corrugated support ring.

[0015] Preferably, the opening directions of the S-shaped connecting rods at two ends of the same corrugated support ring are opposite.

[0016] Preferably, the support portion is located at the belly of the S-shaped connecting rod.

[0017] Preferably, along the axial direction of the corrugated support ring, the minimum spacing between the support portion and an adjacent corrugated support ring is defined as D1, and the spacing between the corrugated support rings on both sides of the support portion is defined as D2. When the corrugated support ring is not expanded, D1≤0.2D2.

[0018] Preferably, when the corrugated support ring is compressed, the distance between the support portion and an adjacent corrugated support ring is zero.

[0019] Preferably, the support portion abuts against a wave crest or a wave trough of an adjacent wave support ring.

[0020] Preferably, the number of wave crests or wave troughs abutting against the same supporting portion is not less than 2.

[0021] Preferably, the upper end and / or the lower end of the S-shaped connecting rod abuts against the S-shaped connecting rod adjacent in the circumferential direction.

[0022] Preferably, the outer opening diameter of the end portion is larger than the diameter of the connection between the inner side and the middle portion.

[0023] Preferably, when the middle portion is fully expanded, the circumferential offset distance between the wave crests and wave troughs connected by the S-shaped connecting rod is less than 1 / 2 of the wavelength of the corrugated support ring.

[0024] Beneficial effects:

[0025] (1) The intracranial vascular stent provided by the present invention forms two or more groups of pushing force transmission channels on an S-shaped connecting rod, so that the pushing force can be more evenly transmitted to the corrugated support ring, reducing the risk of deformation of the stent caused by excessive local pushing force, significantly improving the pushing performance of the stent in the microcatheter, and when the pushing effect in the microcatheter is consistent, the number of connecting rods can be relatively reduced, further improving the bending performance of the stent in the compressed state and the expanded state;

[0026] (2) In the expanded state, when the stent conforms to the curvature of the blood vessel, the inner curvature side of the stent is compressed and the outer curvature side is stretched. Since the relative crests and troughs of the corrugated support ring form a small angle rotational dislocation, the adjacent crests and troughs are staggered, which can avoid interference caused by the compression of the inner curvature side and prevent adjacent crests and troughs from colliding with each other when squeezed. In addition, the S-shaped connecting rod is stretchable in the axial direction of the stent, which can compensate for the stretching of the outer curvature side and the compression of the inner curvature side, thereby adapting to blood vessels with smaller bending radius;

[0027] (3) When the stent is released from the microcatheter, the adjacent S-shaped connecting rods open in opposite directions, which can offset the rotation of the stent along the axis when it is released, thereby preventing the microcatheter from rotating and causing instability in the blood vessel. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0029] Figure 1 This is a schematic diagram of the prior art of using a stent to achieve vascular stenosis and dilation.

[0030] Figure 2 The diagram is a schematic diagram of adjacent corrugated support rings in an existing bracket being connected by a straight-line connecting rod.

[0031] Figure 3 The diagram is a schematic diagram of another method of connecting adjacent corrugated support rings in an existing bracket through a straight-line connecting rod.

[0032] Figure 4 It is a schematic diagram of adjacent corrugated support rings in an existing bracket being connected by a "U"-shaped connecting rod.

[0033] Figure 5 A schematic structural diagram of an intracranial vascular stent in an expanded state provided by an embodiment of the present invention.

[0034] Figure 6 A partial schematic diagram of the middle portion of an intracranial vascular stent provided in an embodiment of the present invention.

[0035] Figure 7 Schematic diagram of the structure of the S-shaped support rod in Example 1 of the present invention.

[0036] Figure 8 Schematic diagram of the distance between the support portion and the adjacent corrugated support ring in some embodiments of the present invention.

[0037] Fig. 9 This is a schematic structural diagram of the corrugated support rings adjacent to the middle portion of an intracranial vascular stent provided in Example 1 of the present invention.

[0038] Fig.10 This is a schematic structural diagram of an intracranial vascular stent in an expanded state provided in Example 1 of the present invention.

[0039] Fig.11 A schematic structural diagram of corrugated support rings adjacent to the middle portion of an intracranial vascular stent provided in Example 2 of the present invention.

[0040] Fig.12 This is a schematic structural diagram of the corrugated support rings adjacent to the middle portion of an intracranial vascular stent provided in Example 3 of the present invention.

[0041] In the figure: 1, end; 2, middle part; 21, corrugated support ring; 22, S-shaped connecting rod; 23, wave crest; 24, wave trough; 221, support part. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0043] Terminology Note:

[0044] In the description of the present invention, "peak" and "trough" refer to the parts where the metal wire or non-metal wire constituting the corrugated support ring is bent, and are located at both ends of the corrugated support ring along its axis. On the same corrugated support ring, the bending at one end is defined as "peak", and the bending parts at the other end opposite to the "peak" are all "troughs". In the description of the present invention, unless otherwise specified, "peak" refers to the bending part at the left end of the corrugated support ring in the drawings of the specification, and "trough" refers to the bending part at the right end of the corrugated support ring in the drawings of the specification.

[0045] In the description of the present invention, "circumferential direction" refers to the direction around the axis of the corrugated support ring.

[0046] In the description of the present invention, "abdomen" refers to the portion of the S-shaped support ring that protrudes toward the direction of the corrugated support ring, "upper end" refers to the portion of the S-shaped support ring located on the upper side of the "abdomen", and "lower end" refers to the portion of the S-shaped support ring located on the lower side of the "abdomen".

[0047] In the description of the present invention, "rotational offset angle" refers to the angle at which the corrugated support rotates around its axis.

[0048] In the description of the present invention, "wavelength" refers to the spacing between adjacent "wave crests" on a corrugated support ring, and the "central angle corresponding to the wavelength" refers to the angle traveled by a "wave crest" when it rotates around the axis of the corrugated support ring to coincide with an adjacent "wave crest".

[0049] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0050] In the description of the present invention, “several” means one or more, “more” means more than two, “greater than”, “less than”, “exceed”, etc. are understood as not including the number itself, and “above”, “below”, “within”, etc. are understood as including the number itself.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the term "connection" should be understood in a broad sense. For example, it can be a fixed connection or a movable connection, a detachable connection or a non-detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be internal connection between two elements, indirect connection, or an interactive relationship between two elements.

[0052] The present invention will be described in detail below in conjunction with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0053] The present invention aims to solve the problem that when an intracranial vascular stent passes through a blood vessel with a large curvature, the required pushing force increases and the stent is prone to local deformation. Figures 5 to 7 As shown, the intracranial vascular stent includes a middle part 2 and an end part 1, the end part 1 is connected to the two ends of the middle part 2, the middle part 2 includes a plurality of corrugated support rings 21 arranged along the axial direction, an S-shaped connecting rod 22 is provided between adjacent corrugated support rings 21, and the two ends of the S-shaped connecting rod 22 are respectively connected to the crest 23 and the trough 24 of the adjacent corrugated support rings 21, as shown in FIG. Fig. 9 As shown, a support portion 221 is provided on the S-shaped connecting rod 22 . When the corrugated support ring 21 is compressed, the support portion 221 can abut against the wave crests 23 and / or wave troughs 24 of the corrugated support ring 21 .

[0054] In the present invention, Figure 5 As shown, the end portions 1 at both ends of the middle portion 2 respectively adopt a closed loop structure and an open loop structure, and the connection between the middle portion 2 and the end portions 1 can be connected by an S-shaped connecting rod 22 or a straight-line connecting rod.

[0055] In the circumferential direction, the number of connecting rods in each circle of the end portion 1 is not less than the number of S-shaped connecting rods 22 in each circle of the middle portion 2. More preferably, the number of S-shaped connecting rods 22 in each circle of the middle portion 2 is less than the number of connecting rods in each circle of the end portion 1, so that the middle portion 2 has better flexibility and can produce a greater degree of bending without plastic deformation, thereby improving its ability to pass tortuous blood vessels.

[0056] More specifically, when the intracranial vascular stent is in a compressed state, if the corrugated support ring 21 is compressed to a certain extent, the support portion 221 can resist the crest 23 and / or trough 24 of the corrugated support ring 21, thereby forming an additional thrust transmission channel based on the connection between the S-shaped connecting rod 22 and the corrugated support ring 21, providing additional support force for the corrugated support ring 21, making the corrugated support ring 21 more evenly stressed, and when passing through a blood vessel with a larger curvature, the above-mentioned arrangement can avoid local deformation of the intracranial vascular stent.

[0057] When the stent bends in the blood vessel, the inner side of the stent is compressed and the outer side is stretched. In the prior art, the crests 23 and troughs 24 in adjacent support rings are arranged relative to each other. When the inner side is compressed and bent, they interfere with each other and cause warping. When the outer side of the stent is stretched, due to the limitation of the straight-line connecting rod on the outer side, the outer side of the stent cannot be stretched compliantly. When the bending radius of the blood vessel is small, it is very easy to bend, resulting in a smaller inner hole of the stent that affects blood flow. The present invention introduces an S-shaped connecting rod 22 between the corrugated support rings 21 in the middle part 2, so that the stent has stretchability in the axial direction. This design allows the S-shaped connecting rod to compensate between the stretching of the outer side and the compression of the inner side, so that the stent can adapt to blood vessels with smaller bending radii and reduce the risk of bends.

[0058] In a preferred embodiment of the present invention, the S-shaped connecting rods 22 are spaced apart in the circumferential direction, and the S-shaped connecting rods 22 are arranged in a circular array around the axis of the corrugated support ring 21, so that the corrugated support ring 21 presents an open-loop structure. When the intracranial vascular stent is released from the compressed state, the corrugated support ring 21 expands radially, and at the same time, due to the presence of the S-shaped connecting rods 22, the adjacent corrugated support rings 21 rotate along their axes, so that the crests 23 and troughs 24 of the adjacent corrugated support rings 21 are misaligned in the circumferential direction. In a blood vessel with a relatively large curvature, such an arrangement can avoid direct collision of the crests 23 and troughs 24 in the adjacent corrugated support rings 21 that are not connected by the connecting rods, and a certain degree of misalignment can prevent the intracranial vascular stent from being folded in a blood vessel with a relatively large curvature.

[0059] In a preferred embodiment of the present invention, Figure 6As shown, the S-shaped connecting rods 22 at both ends of the same corrugated support ring 21 have opposite opening directions. In other embodiments, their opening directions may also be the same. When the intracranial vascular stent is released from the microcatheter, it will rotate along the axis. Since the distal end of the stent contacts the vascular wall first, and the proximal end is still in the microcatheter, the microcatheter will be driven to rotate, thereby inducing instability of the microcatheter in the blood vessel. By arranging S-shaped connecting rods 22 with opposite opening directions at both ends of the corrugated support ring 21, the adjacent corrugated support rings 21 can rotate in opposite directions, thereby offsetting the rotation, so that the stent as a whole is smoothly pushed out of the microcatheter.

[0060] In a preferred embodiment of the present invention, the support portion 221 is located at the belly of the S-shaped connecting rod 22 .

[0061] In a preferred embodiment of the present invention, Figure 8 As shown, along the axial direction of the corrugated support ring 21, the spacing between the support portion 221 and the adjacent corrugated support ring 21 is defined as D1, and the spacing between the corrugated support rings 21 on both sides of the support portion 221 is defined as D2. When the corrugated support ring 21 is not expanded, D1≤0.2D2, so that the corrugated support ring 21 can form an additional thrust transmission channel through the support portion 221 of the S-shaped connecting rod 22 when it is subjected to a small degree of compression.

[0062] In a preferred embodiment of the present invention, when the corrugated support ring 21 is compressed, the distance between the support portion 221 and the adjacent corrugated support ring 21 is zero, that is, the support portion 221 can contact the corrugated support rings 21 on both sides without being compressed by the corrugated support rings 21 on both sides, and form an additional thrust force transmission channel.

[0063] In a preferred embodiment of the present invention, the support portion 221 abuts against the wave crest 23 or wave trough 24 of the adjacent corrugated support ring 21 , so that an additional thrust force transmission channel is formed at the wave crest 23 or wave trough 24 of the corrugated support ring 21 .

[0064] In a preferred embodiment of the present invention, the number of wave crests 23 or wave troughs 24 that abut against the same supporting portion 221 is not less than two, so that one supporting portion 221 can abut against two wave crests 23 or two wave troughs 24 at the same time.

[0065] In a preferred embodiment of the present invention, the upper end and / or lower end of the S-shaped connecting rod 22 abuts against the circumferentially adjacent S-shaped connecting rod 22, so that a thrust force transmission channel can be formed between the S-shaped connecting rods 22, thereby making the circumferential S-shaped connecting rods 22 more evenly stressed and less prone to deformation.

[0066] In a preferred embodiment of the present invention, the outer opening diameter of the end portion 1 is larger than the diameter of the inner side connected to the middle portion 2, so that the end portion 1 is in a bell-mouth shape.

[0067] In a preferred embodiment of the present invention, when the middle portion 2 is fully expanded, the circumferential offset distance between the wave crest 23 and the wave trough 24 connected by the S-shaped connecting rod 22 is less than 1 / 2 of the wavelength of the corrugated support ring 21 .

[0068] The following is a detailed description of an intracranial vascular stent of the present invention through specific embodiments.

[0069] Example 1

[0070] This embodiment provides an intracranial vascular stent, such as Figure 5 As shown, it includes a middle part 2 and an end part 1, and the two ends of the middle part 2 are connected to the end part 1 through an S-shaped connecting rod 22. The end part 1 is in a trumpet shape and consists of two corrugated support rings 21 connected in a closed loop and arranged axially. The middle part 2 includes a plurality of corrugated support rings 21 arranged axially, and an S-shaped connecting rod 22 is arranged between adjacent corrugated support rings 21. The two ends of the S-shaped connecting rod 22 are respectively connected to the crest 23 and the trough 24 of the adjacent corrugated support rings 21. The S-shaped connecting rod 22 is distributed at intervals in the circumferential direction, so that the corrugated support ring 21 of the middle part 2 is an open-loop structure to improve the flexibility and passing capacity of the middle part 2. The S-shaped connecting rods 22 at both ends of the corrugated support ring 21 have opposite opening directions, which can make the force more uniform during pushing.

[0071] When the middle portion 2 expands, Figure 6 As shown, the relative crests 23 and troughs 24 of the corrugated support ring 21 form a small rotational misalignment, so that adjacent crests 23 and troughs 24 are staggered. The rotational misalignment angle is less than 1 / 2 of the central angle corresponding to the wavelength of the corrugated support ring 21, which can avoid the collision between the crests 23 and troughs 24 on the inner bend side when the stent passes through a curved blood vessel.

[0072] In this embodiment, Fig. 9 As shown, a support portion 221 is provided on the S-shaped connecting rod 22, and the support portion 221 is located at the belly of the S-shaped connecting rod 22. When the middle portion 2 is in a compressed state, the support portion 221 is respectively against the crest 23 of the left corrugated support ring 21 and the trough 24 of the right corrugated support ring 21, thereby forming an additional set of pushing force transmission channels, so that the S-shaped connecting rod 22 has better support, reduces the deformation of the S-shaped support rod during the pushing process, and avoids the middle portion 2 from being bent.

[0073] Example 2

[0074] This embodiment provides an intracranial vascular stent, such as Fig.10As shown, it includes a middle part 2 and an end part 1, and the two ends of the middle part 2 are connected to the end part 1 through an "I"-shaped connecting rod. The end part 1 is in a trumpet shape and consists of two corrugated support rings 21 connected in a closed loop and arranged axially. The middle part 2 includes a plurality of corrugated support rings 21 arranged axially, and an S-shaped connecting rod 22 is arranged between adjacent corrugated support rings 21. The two ends of the S-shaped connecting rod 22 are respectively connected to the crest 23 and the trough 24 of the adjacent corrugated support rings 21. The S-shaped connecting rod 22 is distributed at intervals in the circumferential direction, so that the corrugated support ring 21 of the middle part 2 is an open-loop structure to improve the flexibility and passing capacity of the middle part 2. The S-shaped connecting rods 22 at both ends of the corrugated support ring 21 have opposite opening directions, which can make the force more uniform during pushing.

[0075] When the middle portion 2 expands, Figure 6 As shown, the relative wave crests 23 and wave troughs 24 of the corrugated support ring 21 form a small rotational misalignment, and the rotational misalignment angle is less than 1 / 2 of the central angle corresponding to the wavelength of the corrugated support ring 21.

[0076] In this embodiment, the S-shaped connecting rod 22 is provided with a support portion 221, and the support portion 221 is located at the belly of the S-shaped connecting rod 22. When the middle portion 2 is not expanded, Fig.11 As shown, the support portion 221 is respectively against two adjacent wave crests 23 of the left wave support ring 21 and two adjacent wave troughs 24 of the right wave support ring 21, thereby forming two additional sets of thrust force transmission channels.

[0077] Example 3

[0078] The present embodiment provides an intracranial vascular stent, comprising a middle portion 2 and an end portion 1, wherein the two ends of the middle portion 2 are connected to the end portion 1 through an "I"-shaped connecting rod, the end portion 1 is in a trumpet shape, and is composed of two corrugated support rings 21 connected in a closed loop and arranged axially, the middle portion 2 comprises a plurality of corrugated support rings 21 arranged axially, an S-shaped connecting rod 22 is arranged between adjacent corrugated support rings 21, the two ends of the S-shaped connecting rod 22 are respectively connected to the crest 23 and the trough 24 of the adjacent corrugated support rings 21, the S-shaped connecting rod 22 is distributed at intervals in the circumferential direction, so that the corrugated support ring 21 of the middle portion 2 is an open-loop structure, so as to improve the flexibility and passing capacity of the middle portion 2, and the S-shaped connecting rods 22 at the two ends of the corrugated support ring 21 have opposite opening directions, which can make the force more uniform during pushing.

[0079] When the middle portion 2 expands, Figure 6 As shown, the relative wave crests 23 and wave troughs 24 of the corrugated support ring 21 form a small rotational misalignment, and the rotational misalignment angle is less than 1 / 2 of the central angle corresponding to the wavelength of the corrugated support ring 21.

[0080] In this embodiment, Figure 7As shown, the S-shaped connecting rod 22 is provided with a supporting portion 221, and the supporting portion 221 is located at the abdomen of the S-shaped connecting rod 22. When the middle portion 2 is not expanded, as shown in FIG. Fig.12 As shown, the support portion 221 is respectively abutted against two adjacent wave crests 23 of the left corrugated support ring 21 and two adjacent wave troughs 24 of the right corrugated support ring 21, thereby forming two additional groups of thrust force transmission channels, and the upper end and the lower end of the S-shaped connecting rod 22 are respectively abutted against the adjacent S-shaped connecting rods 22, thereby also forming one group of thrust force transmission channels respectively. In this way, a total of three additional groups of thrust force transmission channels are formed, which not only makes the axial force of the middle portion 2 more uniform, but also disperses the force between the S-shaped connecting rods 22, thereby making the force of the S-shaped connecting rods 22 in the circumferential direction more uniform, thereby further improving the bending resistance of the middle portion 2.

[0081] In summary:

[0082] Since the single S-shaped connecting rod of the present invention has multiple groups of pushing force transmission channels, while ensuring the overall flexibility of the stent, the present invention has several times more pushing force transmission channels than the prior art, so that when the stent is pushed, the pushing force can be evenly transmitted between the support rings, successfully reducing the potential risk of deformation of the stent due to excessive local pushing force, and significantly improving the pushing performance of the stent in the microcatheter. In addition, when the pushing effect in the microcatheter is consistent, the number of connecting rods can be relatively reduced, the flexibility of the stent in the compressed state is better, and the bending performance of the stent in the compressed state and the expanded state is further improved. This innovative design can significantly improve the pushability of the stent during surgery, and balances and optimizes the pushing force transmission and stent flexibility of the existing intracranial vascular stent in the compressed state.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An intracranial vascular stent, characterized in that: It comprises a middle part and end parts, the end parts are connected to the two ends of the middle part, the middle part comprises a plurality of corrugated support rings arranged in the axial direction, an S-shaped connecting rod is arranged between adjacent corrugated support rings, the two ends of the S-shaped connecting rod are respectively connected to the crests and troughs of adjacent corrugated support rings, the S-shaped connecting rods are spaced in the circumferential direction, and two supporting parts are arranged on the S-shaped connecting rod, when the middle part expands, the crests and troughs of adjacent corrugated support rings relative to each other form a small rotational misalignment, and the rotational misalignment angle is less than 1 / 2 of the central angle corresponding to the wavelength of the corrugated support ring; The support portion is located at the part of the S-shaped connecting rod that protrudes toward the corrugated support ring. When the middle portion is not expanded, the two support portions respectively offset the two adjacent peaks of the left corrugated support ring and the two adjacent troughs of the right corrugated support ring, thereby forming two additional sets of thrust force transmission channels.

2. An intracranial vascular stent according to claim 1, characterized in that: The S-shaped connecting rods at two ends of the same corrugated support ring are arranged in opposite directions.

3. An intracranial vascular stent according to claim 1, characterized in that: The upper end and / or the lower end of the S-shaped connecting rod abuts against the S-shaped connecting rod adjacent to the circumferential direction.

4. The intracranial vascular stent according to claim 1, characterized in that: The outer opening diameter of the end portion is larger than the diameter of the connection between the inner side and the middle portion.

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