Vertebral artery stent

Abstract

The invention relates to the technical field of medical instruments, in particular to a vertebral artery stent which comprises an outer-layer flexible stent, an inner-layer flexible stent and an outer-layer flexible stent, and the outer-layer flexible stent is of a net tubular structure composed of a metal net and used for supporting the inner wall of a blood vessel; the middle reinforcing layer is arranged on the inner wall of the outer-layer flexible stent and is arranged at the near end of the outer-layer flexible stent; the inner film coating layer is attached to the inner wall of the middle reinforcing layer to form a smooth inner wall; wherein the wall thickness of the vertebral artery stent is gradually reduced from the near end to the far end. According to the vertebral artery stent, the middle reinforcing layer is arranged at the near end of the outer soft layer, so that the near-end supporting strength of the vertebral artery stent is improved, the far end is kept soft, and a guide wire can enter conveniently; and through the arrangement of the inner film covering layer in the middle reinforcing layer, the inner wall of the vertebral artery stent is smooth, the trafficability of the vertebral artery stent is improved, and a guide wire can smoothly pass through the vertebral artery stent conveniently.

Description

Technical Field

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

[0002] The vertebral artery is an important blood vessel responsible for supplying blood to the back of the brain. Stenosis can lead to insufficient blood supply, thereby increasing the risk of stroke or transient ischemic attack. In order to treat vertebral artery stenosis, the existing technology often uses a catheter to deliver a stent to the stenotic site, aiming to support the stenotic blood vessel with the stent and restore blood flow.

[0003] In the prior art, vertebral artery stents are usually made of metal materials with a mesh design. This mesh structure can provide sufficient support during expansion while allowing flexibility and mobility of the blood vessels. This mesh structure also facilitates the growth of vascular endothelial cells on the surface of the stent, reducing the risk of restenosis in the stent.

[0004] However, vertebral artery atherosclerosis can lead to plaque formation, which in turn leads to stenosis at any stage of the vertebral artery. The growth of plaques eventually leads to the formation of vertebral artery thrombosis. After the existing stent is placed, it is difficult for the guidewire to cross the stent to the distal end during subsequent surgical treatment, especially at the entrance of the vertebral artery, because the stent is relatively soft. It is very difficult for the guidewire to pass through the stent. For example, the guidewire is easily inserted into the stent, causing the guidewire to be unable to reach the right position; on the other hand, the existing vertebral artery stent has good flexibility, and the proximal support force is insufficient, which can easily lead to the restenosis of the vertebral artery. Summary of the invention

[0005] In view of at least one of the above technical problems, the present invention provides a vertebral artery stent, which adopts structural improvement to improve the penetration and supporting force of the guide wire.

[0006] According to one aspect of the present invention, there is provided a vertebral artery stent, comprising:

[0007] The outer flexible stent is a tubular structure made of metal mesh, used to support the inner wall of the blood vessel;

[0008] An intermediate reinforcement layer is arranged on the inner wall of the outer flexible support and at the proximal end of the outer flexible support;

[0009] An inner coating layer is adhered to the inner wall of the middle reinforcement layer to form a smooth inner wall;

[0010] Wherein, the wall thickness of the vertebral artery stent is gradually thinner from the proximal end to the distal end.

[0011] In some embodiments of the present invention, the outer layer flexible stent includes a plurality of unit annular structures, and the plurality of unit annular structures are axially arranged to form a grid column structure.

[0012] In some embodiments of the present invention, the unit annular structure is a wavy metal wire, and the extension direction of the crest and trough of the unit annular structure is parallel to the axial direction of the blood vessel.

[0013] In some embodiments of the present invention, the outer layer compliant stent further comprises a connection structure for connecting a plurality of unit annular structures, and the connection structure is in the form of an axially arranged curve.

[0014] In some embodiments of the present invention, the intermediate reinforcement layer includes a plurality of transverse annular supports, and the plurality of transverse annular supports are arranged at intervals along the axial direction.

[0015] In some embodiments of the present invention, the transverse annular support is a wavy metal wire, and the plane where the crests and troughs of the transverse annular support are located is perpendicular to the axial direction of the outer layer flexible support.

[0016] In some embodiments of the present invention, the transverse annular support is fixedly connected to the contact point of the outer flexible support.

[0017] In some embodiments of the present invention, the intermediate reinforcement layer further includes a connecting bridge, and the connecting bridge is an S-shaped structure.

[0018] In some embodiments of the present invention, the length of the intermediate reinforcement layer is shorter than that of the outer layer of the compliant support.

[0019] In some embodiments of the present invention, the thickness of the inner coating layer is gradually reduced from the proximal end to the distal end.

[0020] The beneficial effects of the present invention are as follows: the present invention increases the proximal support strength of the vertebral artery stent by arranging an intermediate reinforcing layer at the proximal end of the outer flexible layer, and maintains flexibility at the distal end, thereby facilitating the entry of a guide wire; and by arranging an inner coating layer inside the intermediate reinforcing layer, the inner wall of the vertebral artery stent is made smooth, thereby improving the passability of the vertebral artery stent and facilitating the smooth passage of the guide wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the axial cross-sectional structure of the vertebral artery stent in an embodiment of the present invention;

[0023] Figure 2is a schematic diagram of a cross-sectional structure perpendicular to the axial direction of a vertebral artery stent in an embodiment of the present invention;

[0024] Figure 3 Schematic diagram of the structure of the vertebral artery stent in an embodiment of the present invention;

[0025] Figure 4 Schematic diagram of the structure of the middle reinforcement layer and the inner coating layer in an embodiment of the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of a vertebral artery stent placed in a blood vessel in an embodiment of the present invention;

[0027] Figure 6 Schematic diagram of the structure of inserting a guide wire into a vertebral artery stent in an embodiment of the present invention.

[0028] In the figure: 1. Outer flexible support; 11. Unit annular structure; 12. Connection structure; 2. Middle reinforcement layer; 21. Transverse annular support; 22. Connection bridge; 3. Inner coating layer. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0032] like Figures 1 to 6 The vertebral artery stent shown in the figure comprises an outer flexible stent 1, an intermediate reinforcement layer 2 and an inner coating layer 3. Figure 1 and Figure 2As shown in the figure, the outer flexible stent 1 is composed of a metal mesh to form a mesh tube structure, which is used to support the inner wall of the blood vessel; it should be pointed out here that the outer flexible stent 1 is no different from the stent structure in the prior art, and the mesh tube structure formed by the metal mesh has good flexibility. This structure can adapt well to the natural curvature of the vertebral artery, reduce mechanical stimulation to the blood vessel, and reduce the risk of vascular damage; when placing the stent, first puncture is performed through the femoral artery, radial artery and other access routes, and a guide catheter is inserted. This catheter pushes the guide system into the vertebral artery. After the guide wire successfully passes through the lesion, the guide wire is used as a track to send the delivery catheter system pre-installed with the stent into the vertebral artery along the guide wire until it reaches the lesion. The stent is released after the guide wire is removed and the stent is in a compressed state in the delivery catheter. When the stent is released from the delivery catheter, the stent begins to expand and adhere to the inner wall of the blood vessel, and the stent is released. The placement method of the vertebral artery stent in the embodiment of the present invention is the same as the above method, but the plaque caused by vertebral artery atherosclerosis will form a stenotic lesion. After the existing stent is placed, in subsequent treatment, it is necessary to continue to place the stent at the distal end of the existing stent. However, the existing stent is relatively soft, especially at the entrance. It is difficult for the existing guide wire to pass through the stent to reach the distal stenotic lesion, and it is easy to insert into the stent or push the stent to cause restenosis.

[0033] In the embodiment of the present invention, in order to solve the above problems, the existing bracket is improved. Please continue to refer to Figure 1 and Figure 2 In the embodiment of the present invention, the intermediate reinforcement layer 2 is arranged on the inner wall of the outer layer flexible support 1 and is arranged at the proximal end of the outer layer flexible support 1; Figure 1 and Figure 2 As shown in the figure, the intermediate reinforcement layer 2 is arranged on the proximal end of the inner wall of the outer flexible stent 1. This structural design strengthens the mechanical properties of the proximal end of the vertebral artery stent, increases the proximal support strength of the outer flexible stent 1, and prevents the guide wire from deforming or collapsing when passing through. At the same time, by increasing the support force of the proximal end of the outer flexible stent 1, the shape of the blood vessel can be maintained more stably, reducing the risk of arterial restenosis caused by deformation or displacement of the proximal end of the stent.

[0034] Please continue to refer to Figure 1 and Figure 2In the embodiment of the present invention, the inner coating layer 3 is attached to the inner wall of the middle reinforcing layer 2 to form a smooth inner wall; through the structure of the inner coating, the proximal end of the outer flexible stent 1 forms a smooth inner wall, which can reduce the friction when the guide wire passes through the outer flexible stent 1, and prevent the distal end of the guide wire from being mistakenly inserted into the mesh of the outer flexible stent 1, thereby improving the passability and operability of the guide wire. It should be pointed out here that there are many materials for the inner coating, which have biocompatibility, durability and anti-thrombotic properties, such as common polytetrafluoroethylene, polyurethane, polyethylene terephthalate and other materials.

[0035] In an embodiment of the present invention, the wall thickness of the vertebral artery stent is set to be gradually thinner from the proximal end to the distal end. Through this structural setting, the proximal end is strong and the distal end is relatively soft. This structure can provide a stronger support force to the proximal end, while the distal end maintains a soft structure, taking into account the support and softness of the stent. Through the thin structure of the distal wall, the flexibility of the distal end is better, the stimulation of the distal end to the blood vessel is reduced, and the guide wire is easier to pass. Of course, it is pointed out here that there are many structural forms of gradually thinning wall thickness in this application, for example, the diameter of the mesh wire of the outer layer of flexible stent 1 can be set thicker at the proximal end and thinner at the distal end; it can also be that the wall thickness of the middle reinforcement layer 2 is thicker in the middle and thinner at the distal end, or it can also be that the wall thickness of the inner layer is set to be gradually thinner from the proximal end to the distal end; in addition, it should be pointed out here that in the embodiment of the present invention, the proximal end and the distal end refer to the end close to the operator relative to the operator as the proximal end, and the end away from the operator as the distal end.

[0036] In the above embodiment, by setting the intermediate reinforcing layer 2 at the proximal end of the outer flexible layer, the proximal support strength of the vertebral artery stent is increased and the distal end remains flexible, thereby facilitating the entry of the guide wire; and by setting the inner coating layer 3 inside the intermediate reinforcing layer 2, the inner wall of the vertebral artery stent is made smooth, thereby improving the passability of the vertebral artery stent and facilitating the smooth passage of the guide wire.

[0037] On the basis of the above embodiments, in the embodiments of the present invention, the specific structure of the outer layer flexible support 1 is as follows: Figure 1 As shown in the figure, the outer layer flexible stent 1 includes a plurality of unit annular structures 11, and the plurality of unit annular structures 11 are axially arranged to form a columnar structure. Through this structural design, the axial arrangement along the blood vessel can well conform to the natural curvature of the vertebral artery, and the annular structural design can provide more uniform support for the blood vessel;

[0038] Please refer to Figure 3In the embodiment of the present invention, the unit annular structure 11 is a wavy metal wire, and the extension direction of the wave crest and the wave trough of the unit annular structure 11 is parallel to the axial direction of the blood vessel. By setting the wavy metal wire, this structure can not only support the blood vessel, but also maintain stability when the artery contracts and relaxes. By designing that the wave crest and the wave trough are parallel to the axial direction of the blood vessel, the contact and pressure distribution of the outer layer of the flexible stent 1 on the blood vessel wall are more uniform, thereby reducing the stress concentration of the local blood vessel wall and reducing the risk of blood vessel damage or restenosis.

[0039] In some embodiments of the present invention, the unit annular structures 11 can be fixed by welding or gluing. In order to further improve the overall flexibility, the outer layer flexible stent 1 also includes a connecting structure 12 for connecting multiple unit annular structures 11. The connecting structure 12 is in the form of a curve arranged axially. By using the connecting structure 12 in the form of a curve, a certain degree of expansion and contraction can occur between the multiple unit annular structures 11, thereby enabling the stent to better adapt to the tortuous structure of the blood vessel.

[0040] For the specific structure of the intermediate reinforcement layer 2, please refer to Figure 2 and Figure 4 The middle reinforcement layer 2 includes a plurality of transverse annular stents 21, and the plurality of transverse annular stents 21 are arranged at intervals along the axial direction. By introducing a plurality of transverse annular stents 21 at the proximal end, the support force of the region is increased. Specifically, the transverse annular stents 21 are wavy metal wires, and the planes where the crests and troughs of the transverse annular stents 21 are located are perpendicular to the axial direction of the outer layer of the flexible stent 1. By arranging the crests and troughs of the wavy metal wires perpendicular to the axial direction of the blood vessel, better radial support force can be provided to ensure that the blood vessel remains open after the stent is implanted. More importantly, when placing the guide wire later, the support force at the proximal end is strengthened due to this structure, making it easier to insert the guide wire.

[0041] In the embodiment of the present invention, in order to improve the integrity of the structure, the transverse annular bracket 21 is fixedly connected to the contact point of the outer layer flexible bracket 1. Through the fixed connection between the transverse annular bracket 21 and the outer layer flexible bracket 1, the different layers of the entire bracket form a complete whole, which is more conducive to the compression and release of the bracket, and can prevent the bracket from being misplaced or displaced during the release process, while maintaining the overall shape consistency of the bracket.

[0042] Please continue to refer to Figure 4In an embodiment of the present invention, the intermediate reinforcement layer 2 also includes a connecting bridge 22, and the connecting bridge 22 is an S-shaped structure. Through the design of the S-shaped connecting bridge 22, on the one hand, the intermediate reinforcement layer 2 can be deployed more smoothly during the stent release process, and on the other hand, a certain elastic space can be provided for the inner coating layer 3. When the inner wall is rubbed by the guide wire, the S-shaped connecting bridge 22 can produce a certain expansion or contraction. After the guide wire passes, the S-shaped connecting bridge 22 returns to its original state, thereby improving the reliability of the inner coating layer 3. In some embodiments of the present invention, four S-shaped connecting bridges 22 are arranged around two adjacent transverse annular stents 21. Through this arrangement, not only does it not affect the grip of the stent, but it also improves the support force of the proximal end of the stent.

[0043] In the embodiment of the present invention, in order to take into account the overall flexibility, the length of the middle reinforcement layer 2 is shorter than the outer flexible support 1. That is, in the embodiment of the present invention, Figure 5 As shown in the figure, the middle reinforcement layer 2 starts from the proximal end of the outer flexible stent 1 and is used to strengthen the structure at the entrance, increase the support force at the proximal end, and prevent the stent from displacement; the distal part maintains the original flexibility to adapt to the natural curvature of the blood vessel.

[0044] In some embodiments of the present invention, the thickness of the inner coating layer 3 is gradually thinned from the proximal end to the distal end. This structural design can reduce blood flow resistance, maintain a smooth blood flow path, reduce the formation of local eddies, and reduce the risk of thrombosis. Of course, it should be pointed out here that in some embodiments of the present invention, the gradual thinning of the inner coating layer 3 is only one implementation method, and the gradual thinning of the wall thickness of the outer flexible stent 1 or the gradual thinning of the intermediate reinforcement layer 2 or any combination of the three layers falls within the protection scope of the present invention.

[0045] In some exemplary embodiments of the present invention, Figure 5 and Figure 6 As shown in , when the stent is subsequently placed, the proximal end of the stent at the entrance of the vertebral artery is structurally strengthened and the inner covering film is designed, so that the guide wire can be easily inserted into the proximal end of the previously placed stent. Due to the setting of the inner covering film of the inner wall, the inner wall is smooth, and the guide wire can easily pass through the stent to reach the distal lesion, as shown in Figure 6 As shown in the figure, the distal end of the delivery catheter with the stent is then guided by the guide wire to reach the lesion to release another stent. Compared with the prior art, the vertebral artery stent structure in the embodiment of the present invention is a gradual change type, with the same outer diameter and different strengths. The distal end is softer and can adapt to the shape of the blood vessel. The proximal end is strong and can reduce the deformation and displacement of the stent. The smooth inner wall allows the guide wire to pass smoothly without entering the internal structure of the stent, thereby making the subsequent stent placement more convenient and efficient.

[0046] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A vertebral artery stent, characterized in that: include: The outer flexible stent is a tubular structure made of metal mesh, used to support the inner wall of the blood vessel; An intermediate reinforcement layer is arranged on the inner wall of the outer flexible support and at the proximal end of the outer flexible support; An inner coating layer is attached to the inner wall of the middle reinforcement layer to form a smooth inner wall; Wherein, the wall thickness of the vertebral artery stent is gradually thinner from the proximal end to the distal end.

2. The vertebral artery stent according to claim 1, characterized in that: The outer layer flexible support comprises a plurality of unit annular structures, and the plurality of unit annular structures are axially arranged to form a grid column structure.

3. The vertebral artery stent according to claim 2, characterized in that: The unit annular structure is a wavy metal wire, and the extension direction of the crest and trough of the unit annular structure is parallel to the axial direction of the blood vessel.

4. The vertebral artery stent according to claim 3, characterized in that: The outer layer flexible support also includes a connection structure for connecting a plurality of unit annular structures, and the connection structure is in the form of an axially arranged curve.

5. The vertebral artery stent according to claim 1, characterized in that: The middle reinforcement layer includes a plurality of transverse annular supports, and the plurality of transverse annular supports are arranged at intervals along the axial direction.

6. The vertebral artery stent according to claim 5, characterized in that: The transverse annular support is a wavy metal wire, and the plane where the wave crests and wave troughs of the transverse annular support are located is perpendicular to the axial direction of the outer layer flexible support.

7. The vertebral artery stent according to claim 6, characterized in that: The transverse annular support is fixedly connected to the contact point of the outer flexible support.

8. The vertebral artery stent according to claim 5, characterized in that: The middle reinforcement layer also includes a connecting bridge, and the connecting bridge is an S-shaped structure.

9. The vertebral artery stent according to claim 1, characterized in that: The length of the middle reinforcement layer is shorter than that of the outer flexible support.

10. The vertebral artery stent according to claim 9, characterized in that: The thickness of the inner coating layer is gradually reduced from the proximal end to the distal end.

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