CN115919519A - Stent Delivery System - Google Patents

Abstract

The present invention provides a stent delivery system comprising: pushing the core wire; the bracket is arranged outside part of the push core wire in a surrounding way and is provided with a plurality of meshes; at least one jack catch subassembly, be located between propelling movement core silk and the support, the jack catch subassembly includes at least one elastic component and two at least jack catches, jack catch and elastic component all locate the propelling movement core silk along the axial cover of propelling movement core silk on, the elastic component is located between two adjacent jack catches and connects two jack catches, the jack catch has at least one bellying, the bellying extends and blocks in the mesh that corresponds along the radial orientation that deviates from propelling movement core silk of propelling movement core silk, the support is in tensile state at the in-process elastic component of propelling movement and withdrawal all the time, so that two adjacent jack catches hold tightly under the effect of elastic component, and then grasp the mesh. The problem that the support is opened insufficiently and cannot be recycled easily due to the fact that the meshes of the support are deformed and enlarged under stress is solved.

Description

Stent Delivery System

technical field

The invention relates to the technical field of medical devices, in particular to a stent delivery system.

Background technique

Aneurysm is a serious arterial vascular disease, which will cause great damage to the human body. On the one hand, the enlargement of the aneurysm will compress the surrounding nerves and arteriovenous tissues, causing physical discomfort or loss of some functions. The tumor is ruptured due to the aging of the tumor wall or external force, which will cause bleeding and endanger life. Especially the rupture of cerebral aneurysm, also known as stroke, has a very high rate of death and disability. However, with the improvement of people's living standards and the deterioration of the environment, the probability of aneurysm morbidity is gradually increasing. If it is not treated in time, it will cause serious damage.

Among the formation sites of aneurysms, intracranial aneurysms are the most difficult to treat. Commonly used aneurysm treatment methods include: 1) Surgical clipping, which needs to be fixed on the neck of the aneurysm with a metal clip. 2) Interventional procedures using embolic materials such as coils and liquid embolic agents to occlude the aneurysm. 3) Interventional surgery using intravascular stents. Among them, compared with traditional craniotomy, interventional surgery has less trauma to patients, faster healing, lower recurrence rate and fewer sequelae, and has been recognized by most doctors and patients. Among them, the use of endovascular stenting reduces the blood flow into the aneurysm by reconstructing the blood flow of the parent vessel, so that the aneurysm gradually shrinks, thereby reducing its "occupancy" effect, while the use of embolization materials cannot solve the "occupancy" effect of the aneurysm. space” problem. Therefore, endovascular stent treatment of aneurysms is currently the most ideal treatment option.

In the interventional operation of the intravascular stent, the main tool for implanting the stent is the delivery system of the stent. Before surgery, the stent has been compressed into a specific location on the delivery system by a special process. Firstly, the doctor determines the location, shape and size of the aneurysm through imaging methods; then selects the appropriate stent specification according to the relevant parameters; then, under the guidance of the image, the stent is delivered from the appropriate place into the human blood vessel, and reaches the lesion point through a specific path ; Subsequently, the delivery system releases the stent, and the stent will expand to support the vessel wall; finally, the released delivery system is pulled out, and the operation process is basically completed.

The key to this operation is that the stent can be accurately positioned during the stent release process. Otherwise, due to the wrong release position of the stent, the stent cannot be fully opened or the blood vessel cannot be expanded, resulting in failure to achieve the desired surgical effect or even surgical failure. However, in actual clinical applications, the stent often needs to be retracted and then repositioned during the release process.

The Chinese patent document with application number CN201510325188.1 discloses a stent delivery system, which controls the release position of the stent by pushing the guide wire to push the anchor component.

The Chinese patent document with the application number CN201610170895.2 discloses a recyclable stent delivery system, through which the end of the stent is clamped by post-fixation, so as to realize the function of recyclability during the release process.

The above-mentioned patent documents innovated on the push and release of the stent, which improved the performance of the stent and the release. However, it can be seen that the above-mentioned patent did not pay attention to the reliability of the stent delivery system after repeated push and retraction. , Part of the stent grid is pushed and retracted, and the mesh of the stent will be deformed and expanded due to the force, resulting in insufficient opening of the stent, non-adhesion to the wall, and failure to recover. The risk of surgical complications is high.

Contents of the invention

The invention provides a stent conveying system, which solves the problem that the mesh of the stent will be deformed and expanded due to the force, which will cause the stent to be easily opened insufficiently, not attached to the wall and unable to be recycled.

In order to solve the above technical problems, the present invention provides a stent delivery system, comprising:

Push the core wire;

a bracket, which is arranged around a part of the pushing core wire, and the bracket has a plurality of mesh holes;

At least one claw assembly is located between the pushing core wire and the bracket, the claw assembly includes at least one elastic member and at least two claws, the claw and the elastic member are both pushed along the pushing The core wire is axially sleeved on the pushing core wire, the elastic member is located between two adjacent claws and connects the two claws, the claw has at least one protrusion, The protruding portion extends in a direction away from the pushing core wire along the radial direction of the pushing core wire and snaps into the corresponding mesh hole. When the stent is pushed and retracted, the elastic member It is always in a stretched state, so that two adjacent claws are clamped under the action of the elastic member, and then grasp the mesh.

Optionally, an expansion body is also provided inside the stent, and the expansion body is fixed on the pushing core wire. In the initial state, the expansion body is held in the stent. When the stent is deployed , the expansion body is self-expanding and used to massage the inner wall of the bracket.

Optionally, the self-expanded outer wall of the expansion body is in close contact with the deployed inner wall of the stent.

Optionally, the stent delivery system further includes at least one pair of stoppers fixed on the pushing core wire, the pair of stoppers includes two first stoppers respectively located on both sides of the claw assembly. A component is used to limit the movement of the claws in the claw assembly along the axial direction of the pushing core wire.

Optionally, the stent delivery system further includes at least one second limiter fixed on the pushing core wire, the second limiter is located on the distal side of the jaw assembly to When the stent is described, the jaws are restricted from moving to the distal end, and a limiting section is provided in the region where the pushing core wire is located on the proximal side of the jaw assembly, and the diameter of the limiting section is larger than the inner diameter of the jaws. In order to limit the proximal movement of the claw when delivering the stent.

Optionally, the claw is rotatably sleeved on the pushing core wire.

Optionally, the claw has a plurality of protrusions, and the plurality of protrusions are distributed along the circumferential direction of the pushing core wire.

Optionally, the size of the end of the jaw that is inserted into the mesh is adapted to the size of the mesh.

Optionally, one end of the raised portion snapped into the mesh has a rounded edge.

Optionally, the claw is made of metal or rigid polymer.

Optionally, the pushing core wire includes a first reducing section, a fixed diameter section and a second reducing section arranged in sequence from the distal end to the proximal end, the first reducing section and the second reducing section The diameter gradually increases from the far end to the proximal end, and the diameter of the sizing section remains constant. The diameter of the sizing section is greater than or equal to the maximum diameter of the first variable diameter section and less than or equal to the second The minimum diameter of the reducing section, the support is arranged around the first reducing section.

Optionally, a reinforcing spring is sheathed on the sizing section.

Optionally, a heat-shrinkable tube is sheathed on the outside of the reinforcement spring and the second diameter-reducing section.

Optionally, the pushing core wire is integrally formed.

Optionally, the pushing core wire has an opposite proximal end and a distal end, and the distal end is sheathed with a spring guide wire.

Optionally, the stent is a mesh structure woven by flexible metal wires, and the material of the flexible metal wires is Nitinol, platinum, platinum-tungsten alloy, stainless steel, cobalt-chromium alloy or cobalt-nickel alloy at least one of the

Optionally, the outer wall of the flexible metal wire is coated with a polymer coating, and a silane layer is also covered between the flexible metal wire and the polymer coating, and the silane layer and the polymer coating are covalently key connection.

Optionally, the elastic member is a spring.

Optionally, the stent delivery system further includes a microcatheter, the pushing core wire and the stent are located in the microcatheter, and the pushing core wire can move along the axial direction of the catheter body to release or Recover the stent.

To sum up, the present invention provides a stent delivery system. A claw and an elastic member are provided between the pushing core wire and the stent, the claw has at least one protruding portion, and the protruding portion is along the The radial direction of the push core wire extends away from the push core wire and snaps into the corresponding mesh, and the elastic member is always in a stretched state during the pushing and retracting process of the stent, so that The two adjacent claws are clamped under the action of the elastic member, and then grasp the mesh, and cooperate with the self-stretching adjustment of the elastic member to avoid stretching and squeezing force on the local mesh, and then It solves the problem that the mesh of the stent will be deformed and expanded due to the force, causing the stent to be prone to insufficient opening, non-adhesion to the wall and failure to recycle.

Description of drawings

Those skilled in the art should understand that the accompanying drawings are provided for better understanding of the present invention, and do not constitute any limitation to the scope of the present invention.

Fig. 1 is a schematic structural diagram of a stent delivery system provided by an embodiment of the present invention.

Fig. 2 is a schematic diagram of the structure of the claw assembly provided in the embodiment of the present invention located in the bracket.

Fig. 3 is a schematic structural view of the claw assembly provided by the embodiment of the present invention.

Fig. 4 is a schematic structural view of a stent delivery system provided by another embodiment of the present invention.

In the attached picture:

10-pushing core wire; 20-bracket; 30-claw assembly; 31-claw; 32-elastic member; 40-microcatheter; 62-Limiting section; 70-Reinforcing spring; 71-Heat shrink tube; 80-Spring guide wire; 90-Fluorescent mark;

310 - Raised portion.

Detailed ways

As mentioned in the background technology, in the interventional operation of intravascular stent, the main tool for implanting the stent is the delivery system of the stent. The key to this operation is that the stent can be accurately positioned during the stent release process, otherwise the stent will be damaged due to the wrong position of the stent release The blood vessels cannot be fully opened or dilated, resulting in failure to achieve the expected surgical effect or even surgical failure. However, in actual clinical applications, the stent often needs to be retracted and then repositioned during the release process.

In the currently disclosed technology, although the push and retraction of the stent is realized, the reliability of the stent delivery system after repeated push and retraction is not considered. Pushing and retracting force, the mesh of the stent will be deformed and expanded due to the force, resulting in insufficient opening of the stent, non-adhesion to the wall and failure to recover, and the risk of surgical complications is high.

In order to solve the above problems, the present invention provides a stent delivery system, by setting claws and elastic members between the pushing core wire and the stent, the claw has at least one protruding portion, and the protruding portion is along the The radial direction of the push core wire extends away from the push core wire and snaps into the corresponding mesh, and the elastic member is always in a stretched state during the pushing and retracting process of the stent, so that The two adjacent claws are clamped under the action of the elastic member, and then grasp the mesh, and cooperate with the self-stretching adjustment of the elastic member to avoid stretching and squeezing force on the local mesh, and then It solves the problem that the mesh of the stent will be deformed and expanded due to the force, causing the stent to be prone to insufficient opening, non-adhesion to the wall and failure to recycle.

In order to make the purpose, advantages and features of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in very simplified form and not drawn to scale, and are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention. In addition, the structures shown in the drawings are often a part of the actual structure. In particular, each drawing needs to display different emphases, and sometimes uses different scales.

As used in the present invention, the singular forms "a", "an" and "the" include plural objects, the term "or" is usually used in the sense of including "and/or", and the term "several" Usually, the term "at least one" is used in the meaning of "at least one", and the term "at least two" is usually used in the meaning of "two or more". In addition, the terms "first", "second "Two" and "third" are used for descriptive purposes only, and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Therefore, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of these features, unless the content clearly states otherwise.

The definitions of "proximal" and "distal" in this article are: "proximal" usually refers to the end of the medical device that is close to the operator during normal operation, and "distal" generally refers to the end of the medical device that is close to the operator during normal operation. The end that first enters the patient's body.

Please refer to the accompanying drawings for description below.

As shown in Figures 1 to 3, Figure 1 is a schematic structural view of a stent delivery system provided by an embodiment of the present invention, Figure 2 is a schematic structural view of a claw assembly provided by an embodiment of the present invention located in a stent, and Figure 3 is a schematic view of the embodiment of the present invention Schematic diagram of the structure of the claw assembly provided in the example. An embodiment of the present invention provides a stent delivery system, including:

Push the core wire 10;

A bracket 20 is arranged around a part of the pushing core wire 10, and the bracket 20 has several mesh holes;

At least one claw assembly 30 is located between the pushing core wire 10 and the support 20, the claw assembly 30 includes at least one elastic member 32 and at least two claws 31, the claw 31 and the The elastic members 32 are sleeved on the pushing core wire 10 along the axial direction of the pushing core wire 10, the elastic members 32 are located between two adjacent claws 31 and connect the two claws 31, the claw 31 has at least one protruding portion 310, and the protruding portion 310 extends in a direction away from the pushing core wire 10 along the radial direction of the pushing core wire 10 and snaps into the corresponding mesh In the hole, the elastic member 32 is always in a stretched state during the pushing and retracting process of the bracket 20, so that the two adjacent claws 31 are clamped under the action of the elastic member 32, and then Grasp the mesh.

By setting the claw 31 and the elastic member 32 between the pushing core wire 10 and the bracket 20, the elastic member 32 is always in a stretched state during the pushing and retracting process of the bracket 20, so that two adjacent The claw 31 is clamped under the action of the elastic member 32, and then grasps the mesh, and cooperates with the self-stretching adjustment of the elastic member 32 to avoid stretching and squeezing force on the local mesh, thereby solving the problem of The mesh of the stent 20 will be deformed and enlarged due to stress, causing the stent 20 to be prone to problems of insufficient opening, non-adherence to the wall and failure to recycle.

Specifically, in this embodiment, the stent delivery system further includes a microcatheter 40, the pushing core wire 10 and the stent 20 are located in the microcatheter 40, and the stent 20 has been compressed to The specific position of the microcatheter 40, the stent 20 is located at the distal end of the pushing core wire 10, and the pushing and returning of the stent 20 is realized by driving the pushing core wire 10 to move in the microcatheter 40. withdraw. For example, by distally advancing the pushing core wire 10 (which may simultaneously retract the microcatheter 40) to release the stent 20 (i.e. protrude the microcatheter 40 forward), the stent 20 can be self-expanding and Support the blood vessel at the lesion point, when the release position of the stent 20 is wrong, and the blood vessel cannot be fully opened or expanded, the pushing core wire 10 can be withdrawn to the proximal end (the microcatheter 40 can be pushed to the distal end at the same time) The stent 20 is retracted (ie the microcatheter 40 is retracted back).

The stent 20 is a special implant product, which is a cylindrical structure formed by weaving a variety of filamentary metal or organic materials that can be implanted into the human body. Viewed from the side, the braided stent 20 is a porous structure, which enables the stent 20 to change the fluid dynamic direction of the blood at the implanted vascular lesion. On the one hand, the blood supply of the original aneurysm is interrupted by the stent 20, and the blood supply of the aneurysm will gradually decrease, so that the aneurysm will gradually shrink and achieve the purpose of healing; on the other hand, the stent 20 provides sufficient support and the role of scaffolding , endothelial cells can climb along the stent 20 and connect to form endothelial tissue, wrapping the entire stent 20, so that the normal blood vessel wall around the aneurysm will not produce new lesions and long-term thrombus due to the interference of blood flow.

The stent 20 can be a self-expanding stent, or can be deployed by other external force, which is not limited in this application. In this embodiment, the stent 20 is a self-expanding stent.

In this embodiment, the support 20 is a mesh structure woven by flexible metal wires. Preferably, the material of the flexible metal wire is at least one of Nitinol, platinum, platinum-tungsten alloy, stainless steel, cobalt-chromium alloy or cobalt-nickel alloy.

Further, the inner and outer walls of the stent 20 are coated with an antithrombotic polymer coating, and a silane layer is also covered between the inner and outer walls of the stent 20 and the polymer coating, and the silane layer and the polymer coating The coating is covalently bonded, and the adhesion of the coating to the wire can be further enhanced by covalently bonding the silane layer to the polymer coating.

Please continue to refer to FIG. 1, the inside of the stent 20 is also provided with an expansion body 50, the expansion body 50 is fixed on the pushing core wire 10, and in the initial state, the expansion body 50 is pressed against the stent 20 Inside, when the stent 20 is deployed, the expansion body 50 is self-expanding and used to massage the inner wall of the stent 20 . That is to say, the expansion body 50 is initially located in the microcatheter 40 and is held together with the stent 20 on the pushing core wire 10. When the stent 20 is deployed, the expansion body 50 Self-expanding is no longer bound by the stent 20. Since the expansion body 50 is located in the stent 20, the expansion body 50 can be placed in the stent by repeatedly pushing and withdrawing the pushing core wire 10. The inside of the stent 20 moves relative to the stent 20, so that the stent 20 that is not fully adhered to the wall can be massaged by the expansion body 50 (that is, the outer wall of the swell body 50 squeezes the inner wall of the branch pipe), so that the stent 20 The internal stress is released, thereby ensuring that the bracket 20 can completely adhere to the wall.

In this embodiment, the expanded diameter of the expanded body 50 is slightly smaller than or equal to the inner diameter of the stent 20 of the stent 20 , so as to massage the stent 20 . better. The self-expanded outer wall of the expansion body 50 adheres to the deployed inner wall of the stent 20 .

In this embodiment, the expansion body 50 is located at the distal end of the stent 20 . It should be understood that the present application does not impose any limitation on the material, shape and length of the expansion body 50 .

The number of the claw assembly 30 is at least one, the number of which mainly depends on the length of the bracket 20, that is to say, when the length of the bracket 20 is longer, in order to better clamp the bracket 20 and to prevent uneven local force on the bracket 20, a plurality of jaw assemblies 30 may be provided along the axial direction of the bracket 20. Of course, the present application does not impose any limitation on the number of the jaw assemblies 30, which may be One, or more than one.

Similarly, the present application does not impose any limitation on the number of jaws 31 included in the jaw assembly 30 , one jaw assembly 30 includes at least two jaws 31 , and between two adjacent jaw assemblies 30 There are no restrictions on the spacing. In this embodiment, there is one claw assembly 30 , and the claw assembly 30 includes an elastic member 32 and two claws 31 .

Preferably, the claw 31 is rotatably sleeved on the pushing core wire 10 . In other words, when the pushing core wire 10 is twisted, the claws 31 remain still. Mainly considering that the blood vessels in the human body are not long and straight, the movement trajectory of the pushing core wire 10 is not a straight line, and usually needs to be bent or twisted. Pushing the core wire 10 can prevent the stent 20 from twisting or even deforming following the pushing core wire 10 , affecting the shape of the stent 20 . In this embodiment, the aperture diameter of the claw 31 is slightly larger than the diameter of the pushing core wire 10 , so that the claw 31 can be rotatably sleeved on the pushing core wire 10 .

Please continue to refer to FIGS. 1-3 , the stent delivery system further includes at least one pair of stoppers fixed on the pushing core wire 10, and the pair of stoppers includes The two first limiting members 60 are used to limit the movement of the two claws 31 in the claw assembly 30 along the axial direction of the pushing core wire 10 . Since the claw 31 is rotatably sleeved on the pushing core wire 10, the first stopper 60 can be provided on both sides of the claw assembly 30 to prevent the claw 31 from The axial movement of the pushing core wire 10 ensures that the protruding portion 310 of the claw 31 can be stably locked into the corresponding mesh hole. For example, the two first limiters 60 include, for example, a distal limiter located on the distal side of the jaw assembly 30 and a proximal limiter located on the proximal side of the jaw assembly 30 , wherein the distal stopper is used to limit the movement of the claw 31 on the distal side to the distal end when the stent 20 is retracted, and the proximal stopper is used to limit the movement of the claw 31 on the proximal side when the stent 20 is transported. Move proximally.

It can be understood that the number of the limiting member pairs should be consistent with the number of the jaw assemblies 30 . In this embodiment, the number of the limiting member pair is one, that is, there are two first limiting members 60 .

Preferably, the first limiting member 60 is visible, so that medical personnel can know the position of the proximal end of the stent 20 and the limit position of the retractable position. Specifically, the first limiting member 60 can be made of a developable material or the first limiting member 60 is coated with a developing material.

Please refer to FIG. 4 , in another preferred embodiment, the stent delivery system further includes at least one second limiting member 61 fixed on the pushing core wire 10 , the second limiting member 61 is located at The distal side of the claw assembly 30 is used to limit the movement of the claw 31 to the distal end when the stent 20 is retracted, and the pushing core wire 10 is located at the proximal side of the claw assembly 30. A limiting section 62 , the diameter of the limiting section is larger than the inner diameter of the claw 31 to limit the proximal movement of the claw 31 when the stent 20 is delivered. Therefore, in this way, only the second limiting member 61 is provided on one side of the jaw assembly 30 to realize the limitation of the jaw 31 .

Similarly, the second limiting member 61 should also have developability.

In this embodiment, the protruding portion 310 extends in a direction away from the pushing core wire 10 along the radial direction of the pushing core wire 10 and snaps into the corresponding mesh hole. The corresponding meaning here can be understood The positions of the protruding portion 310 and the mesh hole are relatively fixed.

Further, the claw 31 has a plurality of protrusions 310 , and the plurality of protrusions 310 are distributed along the circumferential direction of the pushing core wire 10 . The purpose of setting the protruding part 310 is to make the claw 31 contact with the bracket 20, and by cooperating with the self-stretching performance of the elastic member 32, the bracket 20 can be pushed and retracted by the bracket 20. The meshes will be firmly grasped and clamped by the claws 31 to avoid stretching and squeezing force on the local meshes, so the connection with the bracket 20 can be made more stable by arranging a plurality of protrusions 310 .

In this embodiment, there are four protrusions 310, and the four protrusions 310 are distributed along the circumferential direction of the pushing core wire 10, and the included angle between two protrusions 310 is 90°. Of course, the present application does not impose any limitation on the number of the protruding parts 310, and there may be one or more.

Furthermore, the plurality of protrusions 310 are evenly distributed along the circumferential direction of the pushing core wire 10 , so that the force on the stent 20 is even. Similarly, the present application does not impose any limitation on the distribution of the protrusions 310 , which may be uniform or non-uniform.

Furthermore, the size of the end of the jaw 31 that is inserted into the mesh is adapted to the size of the mesh. The adaptation mentioned here refers to the shape and size of the end of the jaw 31. Subject to being able to clamp the mesh, the size of the end of the claw 31 can be equal to, slightly larger or slightly smaller than the aperture of the mesh, as long as the mesh is not deformed greatly. During specific implementation, the end of the claw 31 can be designed according to the shape of the mesh, for example, the mesh is diamond-shaped, and the end of the claw 31 is also designed as a square or a circle, just to hold At the center of the rhombus, and the end faces of the ends of the jaws 31 are in contact with the four sides of the rhombus, or the mesh is also elliptical or circular, the ends of the jaws 31 are also designed is square. Of course, the present application does not impose any limitation on the size and shape of the mesh, nor does it impose any limitation on the size and shape of the end of the claw 31 .

Furthermore, the end of the protrusion 310 snapped into the mesh has a rounded edge, that is to say, the end of the protrusion 310 is relatively smooth without sharp protruding corners, so as to avoid the The raised portion 310 scratches or locally deforms the mesh.

In this embodiment, the claw 31 is made of metal or rigid polymer, that is, the claw 31 is not easily deformed.

In this embodiment, the elastic member 32 is a spring, of course, other elastically deformable or stretchable materials may also be used, and this application does not make any limitation thereto. The two ends of the spring can be connected with the two claws 31 by welding or other fixed connections.

Please continue to refer to FIG. 1 , the pushing core wire 10 includes a first diameter reducing section, a fixed diameter section and a second diameter reducing section arranged in sequence from the distal end to the proximal end, and the first diameter reducing section and the second diameter reducing section The diameter of the diameter section gradually increases from the far end to the proximal end, the diameter of the fixed diameter section remains constant, and the diameter of the fixed diameter section is greater than or equal to the maximum diameter of the first variable diameter section and less than or equal to the The minimum diameter of the second diameter-reducing section, the bracket 20 is arranged around the outside of the first diameter-reducing section. That is to say, the diameter of the distal end of the pushing core wire 10 is relatively small, while the diameter of the proximal end is relatively large. The purpose of such design is to make the distal end of the pushing core wire 10 relatively soft and the proximal end relatively hard, so that The distal end is bent, and the proximal end is easier to force, so that the pushing core wire 10 can reach the lesion point smoothly.

In this embodiment, the pushing core wire 10 is integrally formed to ensure that the mechanical properties of each part of the pushing core wire 10 are consistent. Certainly, the pushing core wire 10 may also be spliced and formed by segment connection, which is not limited in this application.

Further, a reinforcing spring 70 is sheathed on the fixed diameter section. Since the first variable diameter section is provided with parts such as the claw assembly 30 and the first stopper 60, and the diameter of the second variable diameter section is relatively large, the fixed diameter section is relatively large. Local bending is more likely to occur, and the bending resistance of the sizing section is increased by sheathing a reinforcing spring 70 on the sizing section.

Furthermore, a heat-shrinkable tube 71 is sheathed on the outside of the reinforcement spring 70 and the second diameter reducing section. In this embodiment, the heat-shrinkable tube 71 is located between the pushing core wire 10 and the microcatheter 40, and its material is PTFE. resistance while avoiding scratching the inner wall of the microcatheter 40 . In this embodiment, the end of the heat-shrinkable tube 71 is fixedly connected to the pushing core wire 10 , and the reinforcement spring 70 is fixed on the pushing core wire 10 through the heat-shrinkable tube 71 .

Please continue to refer to FIG. 1 , the pushing core wire 10 has a proximal end and a distal end opposite to each other, and a spring guide wire 80 is sleeved on the distal end. In this embodiment, a spring guide wire 80 is sheathed on the end of the first diameter reducing section away from the fixed diameter section. Since there are many branches of blood vessels in the human body, the spring guide wire 80 is arranged to prevent the distal end of the pushing core wire 10 from directly contacting and scratching the blood vessel wall.

Further, the end of the spring guide wire 80 is bent outward in a direction away from the pushing core wire 10 .

Furthermore, the bending angle of the end of the spring guide wire 80 is between 115°-145°.

Please continue to refer to FIG. 1 , the proximal end is provided with a fluorescent marker 90 for prompting medical personnel to use radiation.

It should be understood that, except for the components such as the pushing core wire 10, the bracket 20, the claw assembly 30 and the microcatheter 40 mentioned in this embodiment, those skilled in the art can make other conventional configurations as the actual situation, and this application does not Let me repeat.

To sum up, the embodiment of the present invention provides a stent delivery system, comprising: a pushing core wire; a stent arranged around a part of the pushing core wire, and the stent has several mesh holes; at least one claw assembly, Located between the pushing core wire and the bracket, the claw assembly includes at least one elastic member and at least two claws, the claw and the elastic member are both sleeved along the axial direction of the pushing core wire Provided on the pushing core wire, the elastic member is located between two adjacent claws and connects the two claws, the claw has at least one protruding portion, and the protruding portion is along the The radial direction of the pushing core wire extends away from the pushing core wire and snaps into the corresponding mesh, the elastic member is always in a stretched state during the pushing and retracting process of the stent, The two adjacent claws are clamped under the action of the elastic member, thereby grasping the mesh. By setting claws and elastic pieces between the pushing core wire and the stent, the elastic piece is always in a stretched state during the pushing and retracting process of the stent, so that two adjacent claws are in the Clamp under the action of the elastic member, and then grasp the mesh, cooperate with the self-stretching adjustment of the elastic member to avoid stretching and squeezing force on the local mesh, and then solve the problem that the mesh of the bracket will be deformed due to force. The expansion of the deformation causes the stent to be prone to problems of insufficient opening, non-adhesion to the wall and failure to recycle.

The above description is only a description of the preferred embodiments of the present invention, not any limitation to the scope of the present invention. Any changes and modifications made by those of ordinary skill in the field of the present invention as disclosed above shall fall within the protection scope of the claims.

Claims (19)

1. A stent delivery system, characterized in that, comprising: Push the core wire; a bracket, which is arranged around a part of the pushing core wire, and the bracket has a plurality of mesh holes; At least one claw assembly is located between the pushing core wire and the bracket, the claw assembly includes at least one elastic member and at least two claws, the claw and the elastic member are both pushed along the pushing The core wire is axially sleeved on the pushing core wire, the elastic member is located between two adjacent claws and connects the two claws, the claw has at least one protrusion, The protruding portion extends in a direction away from the pushing core wire along the radial direction of the pushing core wire and snaps into the corresponding mesh hole. When the stent is pushed and retracted, the elastic member It is always in a stretched state, so that two adjacent claws are clamped under the action of the elastic member, and then grasp the mesh. 2. The stent delivery system according to claim 1, wherein an expansion body is arranged inside the stent, and the expansion body is fixed on the pushing core wire and follows the movement of the pushing core wire, initially In this state, the expansion body is pressed and held in the stent, and when the stent is deployed, the expansion body is self-expanding and used to massage the inner wall of the stent. 3 . The stent delivery system according to claim 2 , wherein the self-expanded outer wall of the expansion body adheres to the expanded inner wall of the stent. 4 . 4. The stent delivery system according to claim 1, characterized in that, the stent delivery system further comprises at least one pair of limiting members fixed on the pushing core wire, and the pair of limiting members includes The two first stoppers on both sides of the jaw assembly are used to limit the movement of the jaws in the jaw assembly along the axial direction of the pushing core wire. 5. The stent delivery system according to claim 1, wherein the stent delivery system further comprises at least one second limiter fixed on the pushing core wire, the second limiter is located at the The distal side of the claw assembly is used to limit the movement of the claw to the distal end when the stent is retracted, and a limiting section is set in the region of the pushing core wire located on the proximal side of the claw assembly, so that The diameter of the limiting section is larger than the inner diameter of the claw to limit the proximal movement of the claw when delivering the stent. 6. The stent delivery system according to claim 1, wherein the claw is rotatably sleeved on the pushing core wire. 7 . The stent delivery system according to claim 1 , wherein the claw has a plurality of protrusions, and the plurality of protrusions are distributed along the circumferential direction of the pushing core wire. 7 . 8 . The stent delivery system according to claim 1 , wherein the size of the end of the protruding portion snapped into the mesh is adapted to the size of the mesh. 9 . 9. The stent delivery system according to claim 1, characterized in that, one end of the raised portion snapped into the mesh has a rounded edge. 10. The stent delivery system according to claim 1, wherein the claw is made of metal or rigid polymer. 11. The stent delivery system according to claim 1, wherein the pushing core wire comprises a first variable-diameter section, a fixed-diameter section and a second variable-diameter section arranged sequentially from the distal end to the proximal end, so The diameters of the first variable diameter section and the second variable diameter section gradually increase from the far end to the proximal end, the diameter of the fixed diameter section remains unchanged, and the diameter of the fixed diameter section is greater than or equal to the first variable diameter section. The maximum diameter of the diameter section is less than or equal to the minimum diameter of the second diameter-reducing section, and the bracket is arranged around the first diameter-reducing section. 12. The stent delivery system according to claim 11, wherein a reinforcing spring is sheathed on the fixed-diameter section. 13 . The stent delivery system according to claim 12 , wherein a heat-shrinkable tube is sheathed on the outside of the reinforcement spring and the second diameter-reducing section. 14 . 14. The stent delivery system according to claim 11, wherein the pushing core wire is an integrally formed structure. 15. The stent delivery system according to claim 11, wherein the pushing core wire has a proximal end and a distal end opposite to each other, and the distal end is sheathed with a spring guide wire. 16. The stent delivery system according to claim 1, wherein the stent is a mesh structure woven by flexible metal wires, and the material of the flexible metal wires is Nitinol. Platinum. Platinum-tungsten Alloy. Stainless steel. At least one of cobalt-chromium alloy or cobalt-nickel alloy. 17. The stent delivery system according to claim 16, wherein the outer wall of the flexible metal wire is coated with a polymer coating, and a silane layer is also covered between the flexible metal wire and the polymer coating, so that The silane layer is covalently bonded to the polymer coating. 18. The stent delivery system according to claim 1, wherein the elastic member is a spring. 19. The stent delivery system according to claim 1, wherein the stent delivery system further comprises a microcatheter, the pushing core wire and the stent are both located in the microcatheter, and the pushing core wire Axially movable along the catheter body to release or retrieve the stent.

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