Delivery guide wire and stent delivery system

Abstract

The present application relates to a delivery guidewire, comprising a core wire body, a pushing assembly and a limiting spring; the pushing assembly is sleeved and fixed on the core wire body, and the distal end of the pushing assembly is adapted to push against a stent; the limiting spring is threaded on the core wire body and is located on one side of the distal end of the pushing assembly, the limiting spring is adapted to be arranged inside the stent, and the limiting spring can fill the gap between the inner cavity of the stent in the crimped state and the core wire body. By threading a limiting spring on the core wire body on one side of the distal end of the pushing assembly, the limiting spring can limit the deformation amount of the stent after being stressed, the stent always has a high concentricity with the core wire body, the limiting spring can limit the movement of the stent rod, and improve the transmission efficiency of the proximal delivery force of the operator. The core wire body also has a pushing assembly, the distal end of which can contact the stent and release the stent from the catheter sheath, and the retraction assembly completes the stent delivery.

Description

Technical Field

[0001] The present application relates to the field of medical devices, and in particular to a delivery guidewire and stent delivery system. Background Art

[0002] Minimally invasive neurointerventional surgery is a treatment for vascular aneurysms, which usually involves implanting vascular implants, such as stents, coils, aneurysm occlusion devices, into the lesion site. During the implantation process, a delivery guidewire and a catheter are required. At present, the delivery guidewire uses a core wire body as the delivery body. In order to ensure the delivery performance of the delivery guidewire, the delivery guidewire will be provided with a spring or a cutting sea wave tube as a support component of the core wire body, wherein the spring or cutting sea wave tube must not only be concentric with the core wire body, but also remain relatively fixed with the core wire body.

[0003] Generally speaking, the diameter of the distal end of the spring or the cutting sea wave tube is very different from the diameter of the core wire body. Therefore, it is not easy to ensure that the distal end of the spring and the core wire body are concentric. Usually, a metal ring or other component is required to connect and fix the spring or the cutting sea wave tube to the core wire body.

[0004] The prior art CN115300196A discloses a developing vascular stent with an open middle ring, which is characterized in that the developing area of the stent during surgery is further increased by adding developing points on the stent. However, when the stent is to be released and is in a compressed state, since the distal end, proximal end and middle section of the stent structure all have developing structures, during the assembly process and when the stent is delivered to the patient in the blood vessel, the inner diameter of the position with the developing point on the compressed stent is uneven in thickness with the inner diameter of the remaining positions with only the stent rod (since the stent rod is connected to the developing point, the inner diameter at the developing point is significantly smaller than the inner diameter at the stent rod in the compressed state). The developing point of the stent can be better fixed on the core wire because of its smaller inner diameter, but the remaining stent rods on the stent except the developing point have a larger inner diameter, and the coaxiality of these positions on the stent and the core wire cannot be guaranteed. During delivery, the stent may be offset on the core wire, increasing the uncertainty of the operation. Therefore, a new delivery guide wire is needed to solve the above problems. Summary of the Invention

[0005] In view of this, the present application proposes a delivery guide wire, comprising a core wire body, a pushing assembly and a limit spring; the pushing assembly is sleeved and fixed on the core wire body, and the distal end of the pushing assembly is suitable for pushing the stent; the limit spring is passed through the core wire body and is located on the distal end side of the pushing assembly, and the limit spring is suitable for being set in the stent, and the limit spring can fill the gap between the inner cavity of the stent in a compressed state and the core wire body.

[0006] In a possible implementation, a concentric spring is further included; the concentric spring is passed through and fixed on the core wire body, and the concentric spring is located on the inner side of the pushing assembly, and the pushing assembly is sleeved on the core wire body through the concentric spring.

[0007] In one possible implementation, the pushing assembly includes a pushing developing ring and a supporting portion; the pushing developing ring is made of a developing material, the supporting portion is a hollow cylindrical structure, the pushing developing ring is fixedly connected to the supporting portion, and the pushing developing ring is located at the distal end of the supporting portion; the concentric spring is located on the inner side of part of the pushing developing ring and part of the supporting portion, and the distal outer wall of the concentric spring is in contact with part of the inner wall of the pushing developing ring and is fixedly connected.

[0008] In one possible implementation, there are two limit springs, including a distal limit spring and a proximal limit spring; wherein, the distal limit spring and the proximal limit spring are spaced apart on the core wire body, and the distal limit spring and the proximal limit spring are suitable for supporting different positions of the bracket.

[0009] In a possible implementation, a recovery developing ring is further included; the recovery developing ring is located between the limit spring and the push developing ring, and the diameter of the recovery developing ring is smaller than the diameter of the push developing ring.

[0010] In a possible implementation, a marker band is sleeved on the proximal end of the core wire body; or a marker band groove is opened on the proximal end of the core wire body, and a polymer marker band is arranged in the marker band groove or coated with a biological coating.

[0011] In a possible implementation, a protective end head is provided outside the distal end of the core wire body, and the distal end of the protective end head is a hemispherical structure.

[0012] In a possible implementation, the support portion is a support spring or a cutting hypotube.

[0013] In a possible implementation, the diameter of the developing push ring is equal to the diameter of the supporting portion.

[0014] In a possible implementation, the core wire body has flat units and taper units arranged alternately; wherein, the core wire body includes a proximal connection section, a middle taper section, a middle flat section, a distal taper section, and a distal flat section connected in sequence from the proximal end to the distal end, and the diameter of the core wire body gradually decreases from the proximal direction to the distal direction; the taper of the middle taper section is smaller than the taper of the distal taper section, the axial length of the middle taper section is greater than the axial length of the distal taper section, and the axial length of the middle flat section is greater than the axial length of the distal flat section;

[0015] The limiting spring is installed on the distal taper section and / or the middle flat section.

[0016] In a possible implementation, the core wire body is composed of two sections spliced together. The proximal connection section and the middle taper section form a proximal section structure; the middle flat section, the distal taper section, and the distal flat section form a distal section structure; the proximal section structure and the distal section structure are welded and fixed.

[0017] In a possible implementation, the material of the proximal section structure is stainless steel, and the material of the distal section structure is nitinol.

[0018] In a possible implementation, the pushing assembly is installed at a position of part of the middle flat section and the middle taper section; wherein, the pushing and developing ring is arranged at a position close to the proximal end of the middle flat section, the supporting part is arranged on the middle flat section, or the supporting part is arranged on the middle flat section and part of the middle taper section.

[0019] In a possible implementation, the length of the concentric spring in axial contact with the pushing and developing ring on the core wire body is greater than half of the total axial length of the pushing and developing ring on the core wire body.

[0020] On the other hand, the present application also proposes a stent delivery system, including the delivery guide wire, the stent, and the introducer sheath described in any one of the above implementations; at least a developing point is provided at the distal end and / or the proximal end of the stent. The stent is sleeved on the delivery guide wire, the inner wall of the stent can be in contact with the limiting spring, and the proximal end of the stent abuts against the distal end of the pushing assembly; the introducer sheath is sleeved on the outer periphery of the delivery guide wire and the stent in a crimped state.

[0021] In a possible implementation, the stent is provided with a proximal developer ring, a middle developer ring, and a distal developer ring; the number of the limiting springs is two, including a distal limiting spring and a proximal limiting spring; the distal limiting spring is adapted to be installed between the distal developer ring and the middle developer ring of the stent; the proximal limiting spring is adapted to be installed between the middle developer ring and the proximal developer ring of the stent. Beneficial effects of the present application: By disposing a limiting spring 30 on the distal side of the core wire body 10 located in the pushing assembly 20, the limiting spring 30 can limit the deformation amount of the stent after being stressed. Moreover, the stent 70 always has a high concentricity with the core wire body 10, and the limiting spring 30 can limit the movement of the stent rod, improving the transmission efficiency of the proximal delivery force by the operator. The core wire body 10 is further provided with a pushing assembly 20. The distal end of the pushing assembly can contact the stent 70, release the stent 70 from the distal end of the catheter sheath, and the withdrawal assembly completes the delivery of the stent of the present application.

[0022] Other features and aspects of the present application will become clear from the following detailed description of the exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings included in and constituting a part of this specification, together with the specification, illustrate exemplary embodiments, features, and aspects of the present application and are used to explain the principles of the present application.

[0024] Figure 1 Schematic diagram of the main structure of the stent delivery system according to an embodiment of the present application;

[0025] Figure 2 Partial cross-sectional view of the stent delivery system according to an embodiment of the present application;

[0026] Figure 3 Schematic diagram of the structure of the delivery guide wire according to an embodiment of the present application;

[0027] Figure 4 Half cross-sectional view of the main structure of the stent delivery system according to an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Various exemplary embodiments, features, and aspects of the present application will be described in detail below with reference to the drawings. Like reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0029] It should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application or simplifying the description, rather than indicating or implying 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 construed as a limitation to the present application.

[0030] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0031] As used herein, the word "exemplary" means "serving as an example, embodiment, or illustration". Any embodiment described herein as "exemplary" should not be construed as being superior to or better than other embodiments.

[0032] In addition, for a better description of the present application, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present application can also be implemented without some specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art are not described in detail so as to highlight the gist of the present application.

[0033] Figure 1 Schematic diagram of the main structure of the stent delivery system showing an embodiment of the present application; Figure 2 Partial cross-sectional view of the stent delivery system showing an embodiment of the present application; Figure 3 Schematic diagram of the structure of the delivery guide wire showing an embodiment of the present application; Figure 4 Half cross-sectional view of the main structure of the stent delivery system showing an embodiment of the present application.

[0034] As Figures 1-4 shown, a delivery guide wire includes a core wire body 10, a pushing assembly 20, and a limiting spring 30; the pushing assembly 20 is sleeved and fixed on the core wire body 10, and the distal end of the pushing assembly 20 is adapted to push against the stent 70; the limiting spring 30 is threaded through the core wire body 10 and is located on one side of the distal end of the pushing assembly 20. The limiting spring 30 is adapted to be disposed inside the stent, and the limiting spring 30 can fill the gap between the inner cavity of the stent 70 in the crimped state and the core wire body 10.

[0035] In this embodiment, a limiting spring 30 is disposed through the distal side of the core wire body 10 located at the pushing assembly 20. The limiting spring 30 can limit the deformation amount of the stent after being stressed. Moreover, the stent 70 always has a high concentricity with the core wire body 10. The limiting spring 30 can limit the movement of the stent rod, improving the transmission efficiency of the proximal delivery force of the operator. The core wire body 10 is further provided with a pushing assembly 20. The distal end of the pushing assembly can contact the stent 70, release the stent 70 from the distal end of the catheter sheath, and the withdrawal assembly completes the stent delivery of the present application.

[0036] It should be specifically pointed out here that the limiting spring 30 does not provide a radial supporting force for the stent 70. That is, in the static state, the limiting spring 30 is coaxial with the stent, but the limiting spring 30 does not contact the inner wall of the stent 70. There is a gap between the limiting spring 30 and the stent 70. During the pushing process, the stent 70 deforms and the limiting spring 30 contacts it, playing a role in reducing its deformation. In this way, when the stent 70 is released, the limiting spring 30 will not hinder the release of the stent 70 when the stent 70 is released at the target position due to always contacting the stent 70.

[0037] In one specific embodiment, the core wire body 10 has straight units and taper units arranged alternately. Among them, the core wire body 10 includes a proximal connection section 16, a middle taper section 15, a middle straight section 14, a distal taper section 13, and a distal straight section 12 connected in sequence from the proximal to the distal direction. The diameter of the core wire body 10 gradually decreases from the proximal direction to the distal direction. The taper of the middle taper section 15 is smaller than the taper of the distal taper section 13. The axial length of the middle taper section 15 is greater than the axial length of the distal taper section 13. The axial length of the middle straight section 14 is greater than the axial length of the distal straight section 12.

[0038] In this embodiment, by sequentially connecting two or more straight units and taper units to the core wire body 10, and the diameter of the core wire body 10 gradually decreases from the proximal to the distal direction, the stent 70 is assembled at the positions of the distal taper section 13 and the middle straight section 14. During the delivery of the stent 70 during the operation, the operator applies a force to the proximal connection section 16 located at the proximal end. The middle taper section 15 gradually decreases in diameter from the proximal to the distal direction, so as to extend deeper into the blood vessel. The pushing assembly fixed on the core wire body 10 further pushes the stent 70 in the distal direction at its distal end.

[0039] It should be clear here that the straight unit referred to in this application is a cylindrical section structure with different diameters on the delivery guide wire, and the taper unit is an inclined column section structure with an inclined slope on the side wall of the delivery guide wire. More specifically, the alternating arrangement of the straight unit and the taper unit means "the straight unit and the taper unit are arranged at intervals", that is, there is at least one taper unit between at least two adjacent straight units, and there is a straight unit between two adjacent taper units. The taper unit is provided to facilitate the operator to further push the delivery guide wire described in this application into a more distal and thinner blood vessel.

[0040] In one specific embodiment, the total length of the core wire body 10 is in the range of 1500 - 2200 mm, and the minimum diameter of the distal taper section 13 is in the range of 0.04 mm - 0.07 mm.

[0041] In one specific embodiment, the core wire body 10 is composed of two sections spliced together. The proximal connecting section 16 and the middle taper section 15 form the proximal section structure, and the middle straight section 14, the distal taper section 13, and the distal straight section 12 form the distal section structure. The proximal section structure and the distal section structure are welded and fixed.

[0042] In this embodiment, it should also be specifically pointed out that taper units and straight units can also be added to the proximal connecting section 16, that is, the proximal connecting section 16 includes a proximal straight section 161 and a proximal taper section 162. As Figure 3 shown, the distal end of the proximal straight section 161 is connected to the proximal end of the middle taper section 15, and the proximal end of the proximal straight section 161 is connected to the distal end of the proximal taper section 162. The farther the diseased body position is from the operating end, the more taper units are required to gradually reduce the diameter of the distal end of the core wire body 10. Those skilled in the art can select a suitable delivery guide wire by themselves and will not be elaborated too much in this article.

[0043] In one specific embodiment, the material of the proximal section structure is stainless steel, and the material of the distal section structure is nitinol.

[0044] In this embodiment, preferably, the core wire body 10 is made by butt welding and grinding two materials, stainless steel and nitinol. Specifically, the proximal connecting section 16 and the middle taper section 15 form the proximal section structure, and the middle straight section 14, the distal taper section 13, and the distal straight section 12 form the distal section structure. The proximal section structure made of stainless steel and the distal section structure made of nitinol are butt welded and assembled. The nitinol material is relatively stable. Using the nitinol material in the distal section structure of the core wire body 10 can ensure that the attenuation degree of force is lower at the distal end of the core wire body 10, thereby ensuring that the stent delivery system of this application has higher delivery efficiency.

[0045] In one specific embodiment, a marker band groove 163 is provided on the proximal connecting section 16 near its proximal side.

[0046] In this embodiment, preferably, the depth of the marking belt groove 163 is in the range of 0.01 mm to 0.02 mm, and the width of the marking belt groove 163 is in the range of 30 mm to 80 mm.

[0047] In one specific embodiment, the pushing assembly 20 includes a pushing developing ring 21 and a supporting portion 22. The supporting portion 22 is a hollow cylindrical structure. The distal end of the supporting portion 22 is fixedly connected to the pushing developing ring 21, and the pushing developing ring 21 is made of developing material.

[0048] In this embodiment, the support part 22 can be a support spring or a cutting sea wave tube, and the support spring or the cutting sea wave tube is arranged in the middle cone section 15 of the core wire body 10. The proximal end of the support spring or the cutting sea wave tube can contact the cone surface of the core wire body 10, and the push-developing ring 21 is fixed at the distal end of the support part 22.

[0049] In this embodiment, the support portion 22 is passed through the core wire body 10 to provide a greater axial support force for the core wire body 10 which gradually becomes thinner from the proximal end to the distal end, so as to facilitate the operator to push the entire assembly toward the distal end.

[0050] In one specific embodiment, a concentric spring 80 is further included. The concentric spring 80 is arranged on the core wire body 10. The concentric spring 80 is located on the inner side of the partial push-developing ring 21 and the partial support portion 22, and the distal outer wall of the concentric spring 80 is in contact with the inner wall of the partial push-developing ring 21 and is fixedly connected.

[0051] In this embodiment, preferably, the distal end of the concentric spring 80 is inserted into the push developing ring 21 at two-thirds of the axial length of the core wire body 10, and the other end is sleeved on the core wire and inserted into the support spring. The inner diameter gap between the concentric spring 80 and the push developing ring 21 is between 0.008mm and 0.025mm, and the part of the concentric spring 80 inserted into the push developing ring 21 is not tightly wound, and the length of the concentric spring 80 is within the range of 20mm-100mm. The outer diameter gap between the concentric spring 80 and the inner diameter of the support spring is between 0.01mm and 0.03mm. The push developing ring 21, the concentric spring 80 and the support spring are fixedly connected at the connection between the three by dispensing glue or soldering. The distal end of the concentric spring 80 is not tightly wound to facilitate the passage of tin or glue, so as to make the connection strength of each component greater.

[0052] It should also be specifically pointed out that during assembly, the concentric spring 80 must first be fixed to the preset position of the core wire body 10, and then the push assembly 20 and the limit spring 30 are assembled and fixed, and the bracket 70 is installed. The concentric spring 80 can ensure that the support spring or the cutting sea wave tube is more closely matched with the core wire body 10 in the area near the distal end, so that the concentricity of the support spring or the cutting sea wave tube and the core wire is better.

[0053] In one specific embodiment, the number of the limiting springs 30 is two, including a distal limiting spring 31 and a proximal limiting spring 32. The distal limiting spring 31 and the proximal limiting spring 32 are arranged at intervals on the core wire body 10. The distal limiting spring 31 is adapted to be installed between the distal developing ring 72 and the middle developing ring 73 of the stent 70, and the proximal limiting spring 32 is adapted to be installed between the middle developing ring 73 and the proximal developing ring 74 of the stent 70.

[0054] It should be clearly pointed out that the developing rings on the stent 70 referred to in this application are specifically composed of multiple developing points. For example, a circle of developing points in the circumferential direction of the core wire body 10 at the distal end of the stent forms the distal developing ring 72, a circle of developing points in the circumferential direction of the core wire body 10 at the middle of the stent 70 or two adjacent circles of developing points form the middle developing ring 73, and a circle of developing points in the circumferential direction of the core wire body 10 at the proximal end of the stent 70 forms the proximal developing ring 74.

[0055] In this embodiment, since the middle of the stent 70 has a middle developing ring 73, and the diameter of the middle developing ring 73 is larger than that of the stent rod near this position. When the stent is in the compressed state, the occupied space of the developing ring 72 is relatively large. Therefore, there is no limiting spring 30 at this position of the delivery guide wire. The limiting spring 30 is only fixed at the position of the stent 70 without a developing ring, that is, the limiting spring 30 only restricts the stent rod 71 of the stent 70, which is convenient for stent assembly. For other parts of the stent body except the middle developing ring 72 and the developing rings at both ends, when in the crimped state, the gap between the inner wall of the stent 70 and the distal end of the core wire is relatively large. If the movement space of the stent rod 71 of the stent 70 is not restricted, it will cause low transmission efficiency of the proximal pushing force and too large delivery resistance. Therefore, between the radio-opaque protective tip 50 and the retrieval developing ring 40, two limiting springs 30 are arranged to fill the gap between the inner wall of the stent and the core wire after the stent 70 is crimped, to prevent the stent 70 from being unstable or bent after being stressed.

[0056] Preferably, the proximal limiting spring 32 and the distal limiting spring 31 are preferably fixed to the core wire body 10 by welding or dispensing.

[0057] More specifically, the stent delivery system of the present application is used in cooperation with a microcatheter: First, the distal tip of the introducer sheath 60 is fixed to the Luer connector of the microcatheter with a hemostatic valve, and after locking, the introducer sheath 60 is kept stationary. The core wire body 10 is pushed by the pushing assembly 20 to deliver the stent 70 to the microcatheter until the distal end of the microcatheter. During the delivery process, the proximal developing ring of the stent 70 is stuck between the pushing developing ring 21 and the retrieval developing ring 40, the middle developing ring of the stent is stuck between the distal limiting spring 31 and the proximal limiting spring 32, and the distal developing ring of the stent 70 is stuck between the protective tip 50 and the distal limiting spring 31. The stent 70 is adjusted to the lesion position by delivery, the microcatheter is retracted, the stent 70 is released in situ, and the stent delivery system is retracted.

[0058] In one specific embodiment, a recovery developing ring 40 is further included. The recovery developing ring 40 is located between the limiting spring 30 and the pushing developing ring 21 , and the diameter of the recovery developing ring 40 is smaller than the diameter of the pushing developing ring 21 .

[0059] In one specific embodiment, a marker band 11 is sleeved on the proximal side of the core wire body 10, or a marker band groove is opened on the proximal side of the core wire body 10, and a marker band 11 is arranged in the groove of the marker band 11 or coated with a biological coating.

[0060] A heat shrink tube is put on the marker band groove 163 at the proximal end of the core wire. After heating the heat shrink tube, the heat shrink tube is tightly wrapped in the groove to form a marker band 11. The marker band 11 can be a whole marker band 11, or a striped marker band 11 can be formed by cutting off part of the heat shrink tube from the whole marker band 11. The heat shrink tube is wrapped around the marker band groove 163 of the core wire body 10, and the outer diameter after heat shrinkage is flush with the outer diameter of the stent delivery guide wire. This reduces the feeling of the marker band 11 entering the microcatheter during the delivery of the stent 70. It reduces the difficulty of the production and processing technology and reduces costs.

[0061] Alternatively, a colored coating, such as PTFE or another biosafe coating, can be sprayed onto the marking groove 163 of the core wire. After the coating cures, it can be ground to the same outer diameter as the core wire. Alternatively, the core wire can be ground to form spaced marking grooves 163, forming a circular structure. PTFE coating can then be sprayed onto the marking grooves 163, and after the coating cures, the marking band 11 can be used.

[0062] In one specific embodiment, a protective end cap 50 is provided outside the distal end of the core wire body 10 , and the distal end of the protective end cap 50 is an arc-shaped structure.

[0063] In one specific embodiment, the support portion 22 may be a support spring or a cutting hypotube.

[0064] The supporting spring and the cutting hypotube can be directly realized by using the existing technology. In this application, no improvement is made to the structure of the spring and the structure of the hypotube.

[0065] In one embodiment, the diameter of the developing push ring 21 is equal to the diameter of the supporting portion 22 .

[0066] In one specific embodiment, the limit spring 30 is installed on the distal tapered section 13 and / or the middle straight section 14 .

[0067] In one specific embodiment, the pushing component 20 is installed at the positions of the straight middle section 14 and the middle tapered section 15 of the part. Among them, the pushing and developing ring 21 is arranged at the proximal end of the straight middle section 14. Since the supporting part 22 has a relatively long axial length on the core wire body 10, after the supporting part 22 is fixedly connected to the proximal end of the pushing and developing ring 21, it can be integrally arranged on the straight middle section 14, or the supporting part 22 is arranged on the straight middle section 14 and part of the middle tapered section 15.

[0068] In one specific embodiment, the length of the concentric spring 80 in axial contact with the pushing and developing ring 21 on the core wire body 10 is greater than one-half of the total axial length of the pushing and developing ring 21 on the core wire body 10.

[0069] On the other hand, the present application also proposes a stent delivery system, including the delivery guide wire, the stent 70 and the introducer sheath 60 described in any of the above embodiments; at least a developing point is provided at the distal end and / or proximal end of the stent. The stent 70 is threaded on the delivery guide wire. The inner wall of the stent 70 can be in contact with the limiting spring 30, and the proximal end of the stent 70 abuts against the distal end of the pushing component 20; the introducer sheath 60 is sleeved on the outer periphery of the delivery guide wire and the stent 70 in a crimped state.

[0070] In one specific embodiment, the stent has a proximal developing ring 74, a middle developing ring 73 and a distal developing ring 72; the number of the limiting springs 30 is two, including a distal limiting spring 31 and a proximal limiting spring 32. The distal limiting spring 31 is suitable for being installed between the distal developing ring 72 and the middle developing ring 73 of the stent 70, and the proximal limiting spring 32 is suitable for being installed between the middle developing ring 73 and the proximal developing ring 74 of the stent 70.

[0071] The various embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technologies in the market, or to enable other ordinary skilled persons in the technical field to understand the embodiments disclosed herein.

Claims

1. A delivery guide wire, characterized in that, It includes a core wire body, a pushing component and a limit spring; The pushing assembly is sleeved and fixed on the core wire body, and the distal end of the pushing assembly is suitable for pushing the stent; The limit spring is passed through the core wire body and is located at the distal end of the pushing assembly. The limit spring is suitable for being arranged in the stent. The limit spring can fill the gap between the inner cavity of the stent in a compressed state and the core wire body; Also included are concentric springs; The concentric spring is fixed on the core wire body, and the concentric spring is located on the inner side of the pushing assembly, and the pushing assembly is sleeved on the core wire body through the concentric spring; The pushing assembly includes a pushing developing ring and a supporting portion; The push-developing ring is made of a developing material, the support portion is a hollow cylindrical structure, the push-developing ring is fixedly connected to the support portion, and the push-developing ring is located at the distal end of the support portion; The concentric spring is located inside a portion of the push-developing ring and a portion of the support portion, and the distal outer wall of the concentric spring is in contact with a portion of the inner wall of the push-developing ring and is fixedly connected; There are two limit springs, including a distal limit spring and a proximal limit spring; The distal limit spring and the proximal limit spring are spaced apart from each other on the core wire body, and the distal limit spring and the proximal limit spring are suitable for supporting different positions of the stent.

2. The delivery guide wire according to claim 1, wherein, Also included is a recycling developer ring; The recovery developing ring is located between the limiting spring and the pushing developing ring, and the diameter of the recovery developing ring is smaller than the diameter of the pushing developing ring.

3. The delivery guide wire according to claim 1, characterized in that, A marking band is sleeved on the proximal end of the core wire body; Alternatively, a marker groove is provided on the proximal end of the core wire body, and a polymer marker is provided in the marker groove or coated with a biological coating.

4. The delivery guide wire according to claim 1, wherein A protective end head is provided outside the distal end of the core wire body, and the distal end of the protective end head is a hemispherical structure.

5. The delivery guide wire according to claim 1, characterized in that, The support portion is a support spring or a cutting hypotube.

6. The delivery guide wire according to claim 1, wherein The diameter of the developing push ring is equal to the diameter of the supporting portion.

7. The delivery guide wire according to claim 1, wherein, The core wire body comprises straight units and tapered units arranged alternately; The core wire body includes a proximal connecting section, a middle tapered section, a middle straight section, a distal tapered section, and a distal straight section sequentially connected from the proximal end to the distal end, and the diameter of the core wire body gradually decreases from the proximal end to the distal end; The taper of the middle cone section is smaller than that of the distal cone section, the axial length of the middle cone section is greater than that of the distal cone section, and the axial length of the middle straight section is greater than that of the distal straight section; The limit spring is installed on the distal conical section and / or the middle straight section.

8. The delivery guide wire according to claim 7, characterized in that, The core wire body is composed of two sections, wherein the proximal connecting section and the middle cone section form a proximal section structure; The middle straight section, the distal tapered section and the distal straight section constitute a distal section structure; The proximal segment structure and the distal segment structure are fixed by welding.

9. The delivery guide wire according to claim 8, characterized in that, The material of the proximal segment structure is stainless steel, and the material of the distal segment structure is nickel titanium.

10. The delivery guide wire according to any one of claims 7-9, characterized in that, The pushing assembly is installed at a portion of the middle straight section and the middle tapered section; Wherein, the pushing developing ring is arranged at a position near the proximal end of the middle straight section, the supporting part is arranged on the middle straight section, or the supporting part is arranged on the middle straight section and part of the middle tapered section.

11. The delivery guide wire according to claim 1, characterized in that, The length of the concentric spring in axial contact with the pushing developing ring on the core wire body is greater than one half of the total axial length of the pushing developing ring on the core wire body.

12. A stent delivery system, characterized in that, Comprising the delivery guide wire, the stent and the introducer sheath according to any one of claims 1-11; At least a developing point is provided at the distal end and / or proximal end of the stent, the stent is threaded on the delivery guide wire, the inner wall of the stent can be in contact with the limiting spring, and the proximal end of the stent abuts against the distal end of the pushing assembly; The introducer sheath is sleeved on the outer periphery of the delivery guide wire and the stent in the crimped state.

13. The stent delivery system according to claim 12, wherein The stent has a proximal developing ring, a middle developing ring and a distal developing ring; The number of the limiting springs is two, including a distal limiting spring and a proximal limiting spring; The distal limiting spring is suitable for being installed between the distal developing ring and the middle developing ring of the stent; The proximal limiting spring is suitable for being installed between the middle developing ring and the proximal developing ring of the stent.

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