A coil embolization assisted stent system

Abstract

The present invention discloses a coil embolization-assisted stent system, which includes a stent and a delivery system for delivering the stent. The stent includes a main body section and a head section connected to each other. The head section includes a plurality of diamond-shaped closed loops connected to each other in the circumferential direction. The main body section includes a plurality of thick long rod groups and thin short rod groups arranged at intervals in the axial direction. The thick long rod groups and the thin short rod groups are connected to each other by 4 connecting rods arranged in the circumferential direction. For the coil embolization-assisted stent system provided by the present invention, a plurality of thick long rod groups and thin short rod groups are arranged at intervals on the main body section of the stent. The head section includes a plurality of diamond-shaped closed loops connected to each other in the circumferential direction. The diamond-shaped closed loops can provide more connection points to help stabilize the delivery system. The adjacent thick long rod groups and thin short rod groups are connected by connecting rods to form a flower-shaped grid unit. This arrangement makes the stent form a relatively compact structure, which can provide better supporting force and prevent the stent from collapsing.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and particularly to a coil embolization assisted stent system. Background Art

[0002] The rupture of an aneurysm is one of the causes of hemorrhagic stroke, and a large proportion of the causes of hemorrhagic stroke are caused by hypertension and hyperlipidemia. At present, the interventional treatment techniques for intracranial aneurysms can be divided into two major categories: reconstructive treatment and non-reconstructive treatment according to whether the parent artery is preserved. The reconstructive treatment techniques include methods such as simple coil embolization within the aneurysm, balloon-assisted embolization, stent-assisted embolization, and flow diversion devices. The treatment aim is to keep the parent artery unobstructed while changing the hemodynamics within the aneurysm until the aneurysm is completely isolated from the circulatory system to eliminate the bleeding risk. Among them, simple coil embolization is the main method and also the preferred treatment method for intracranial narrow-neck aneurysms currently.

[0003] The coil embolization technique involves placing one or more tiny coils (also known as coils or curls) inside the aneurysm to promote blood coagulation and ultimately seal the aneurysm. These coils will fill the cavity of the aneurysm and block the blood from entering the aneurysm. However, when dealing with wide-neck aneurysms, the coils are prone to displacement or prolapse, which may block the artery or cause poor blood flow, and even trigger cerebrovascular events such as cerebral infarction. If a stent is placed at the neck of the aneurysm to act as a fence or support, it can prevent the coils from moving or prolapsing. Therefore, the application of the intracranial embolization assisted stent system has solved many treatment problems of wide-neck aneurysms.

[0004] For example, in the patent with the authorization announcement number CN205006965U and the authorization announcement date of February 3, 2016, named "An Embolization Device for Assisting the Aneurysm Neck", the patent relates to an embolic device for assisting the aneurysm neck. The embolic device includes a microcatheter, a fixation guide wire, a visualization guide wire, an embolic device body, and an auxiliary device. The visualization guide wire is fixed on the auxiliary device at the distal end of the embolic device body. The fixation guide wire passes through the auxiliary device and the inside of the microcatheter. The two ends of the embolic device body are funnel-shaped in the deployed state, and the conical angle is 20 - 70 degrees. The embolic device body is a three-dimensional spatial structure woven into a grid by 8 - 20 memory metal wires. The deformation amount of the metal wires in the middle part of the embolic device body protrudes to form a protrusion. The angle of the protrusion is 110 - 160 degrees. Its advantages are as follows: it improves the safety of treatment and has less trauma. When it is difficult to embolize the aneurysm with simple coils, it can support in the parent artery to assist coil embolization, and after embolization, it can be completely retrieved outside the body. Compared with balloon-assisted embolization, it avoids the disadvantage of ischemic complications caused by long-term blocking of the blood flow in the parent artery.

[0005] The deficiencies including the above-mentioned patents are that the closed-loop stent or braided stent forms a relatively loose structure, and the radial supporting force of the braided stent is too small to directly fill the aneurysm cavity. When the aneurysm neck is wide, even if the coils form a basket, they cannot stay stably in the aneurysm cavity, easily leading to problems such as thrombosis formation in the aneurysm carrying the tumor, stent displacement, or stent collapse. Summary of the Invention

[0006] The object of the present invention is to provide a coil embolization-assisted stent system to solve the above deficiencies in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A coil embolization-assisted stent system includes a stent and a delivery system for delivering the stent. The stent includes a main body section and a head section connected to each other. The head section includes a plurality of diamond-shaped closed loops connected to each other in the circumferential direction. The main body section includes a plurality of thick long rod groups and thin short rod groups arranged at intervals in the axial direction, and the thick long rod groups and the thin short rod groups are connected by 4 connecting rods arranged in the circumferential direction.

[0009] In the above-mentioned coil embolization-assisted stent system, the thick long rod group includes a plurality of thick long rods, and the thin short rod group includes a plurality of thin short rods.

[0010] In the above-mentioned coil embolization-assisted stent system, the four thin short rods are connected end to end to form a diamond-shaped closed loop.

[0011] In the above-mentioned coil embolization-assisted stent system, the angle formed by the thick long rod and the central axis is 30° - 40°, and the angle formed by the thin short rod and the central axis is 30° - 40°.

[0012] In the above-mentioned coil embolization-assisted stent system, adjacent thick long rod groups and thin short rod groups are connected by connecting rods to form a flower-shaped grid unit. The stent includes a plurality of flower-shaped grid units, and the flower-shaped grid units are arranged in a cosine wave.

[0013] In the above-mentioned coil embolization-assisted stent system, flare portions are respectively provided at the distal end of the main body section and the proximal end of the head section, and a plurality of platinum-iridium marker rings are provided on the flare portions.

[0014] In the above-mentioned coil embolization-assisted stent system, the flare angle of the flare portion is 10° - 20°.

[0015] The above-mentioned coil embolization-assisted stent system, the delivery system includes a pusher wire and a delivery section, the delivery section includes a proximal support spring and a distal support spring, a proximal limit ring is arranged on the proximal support spring, a distal limit ring is arranged on the distal support spring, and the stent is located on the delivery section.

[0016] In the above-mentioned coil embolization-assisted stent system, the radial dimension of the proximal support spring is greater than that of the distal support spring.

[0017] In the above-mentioned coil embolization-assisted stent system, the delivery system further includes a protective sheath tube, and the protective sheath tube is used for preloading the stent and transferring the stent into a microcatheter, so as to release the stent in the aneurysm-bearing blood vessel.

[0018] In the above technical solution, in a coil embolization-assisted stent system provided by the present invention, a plurality of thick long rod groups and thin short rod groups are arranged at intervals on the main body section of the stent, and the head section includes a plurality of diamond-shaped closed loops connected in sequence in the circumferential direction. The diamond-shaped closed loops can provide more connection points to help stabilize the delivery system. The adjacent thick long rod groups and thin short rod groups are connected by connecting rods to form a flower-shaped grid unit. This arrangement makes the stent form a relatively tight structure, can provide better supporting force, and avoid the stent from collapsing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0020] Figure 1 It is a schematic structural diagram of the stent provided by the embodiment of the present invention;

[0021] Figure 2 It is a schematic structural diagram of the stent provided by the embodiment of the present invention;

[0022] Figure 3 It is a schematic assembly structure diagram of the platinum-iridium radiopaque ring provided by the embodiment of the present invention;

[0023] Figure 4 It is a schematic structural diagram of the delivery system provided by the embodiment of the present invention;

[0024] Figure 5 It is a schematic structural diagram when the stent system provided by the embodiment of the present invention is assembled;

[0025] Figure 6 It is a schematic structural diagram of the stent system provided by the embodiment of the present invention in the aneurysm-bearing blood vessel;

[0026] Figure 7 Schematic diagram of the partial release structure of the stent provided by the embodiment of the present invention;

[0027] Figure 8 Schematic diagram of the complete release structure of the stent provided by the embodiment of the present invention;

[0028] Figure 9 Schematic diagram of the structure of the delivery system provided by another embodiment of the present invention;

[0029] Figure 10 Schematic diagram of the structure when the stent system of the present invention is assembled;

[0030] Figure 11 Schematic diagram of the partial release structure of the stent provided by another embodiment of the present invention;

[0031] Figure 12 Partial schematic diagram of the structure of the delivery system provided by yet another embodiment of the present invention;

[0032] Figure 13 Schematic diagram of the structure of the protective sheath tube provided by yet another embodiment of the present invention;

[0033] Figure 14 Schematic diagram of the structure of the microcatheter provided by yet another embodiment of the present invention;

[0034] Figure 15 Partial schematic diagram of the structure of the stent provided by yet another embodiment of the present invention in the limited state.

[0035] Explanation of reference numerals:

[0036] 1. Stent; 1.2 Head section; 1.3 Main body section; 1.4 Rhombic closed loop; 2. Thin and short rod group; 3. Thick and long rod group; 4. Connecting rod; 5. Platinum-iridium marker ring; 6. Flower-shaped grid unit; 7. Pushing wire; 7.1 Laser marker; 8. Delivery section; 8.1 Proximal support spring; 8.11 Proximal limit ring; 8.2 Distal support spring; 8.22 Distal limit ring; 8.3 Marker spring; 9. Protective sheath tube; 10. Microcatheter; 11. Parent vessel; 11.1 Aneurysm; 12. Elastic limiting member; 12.1 Proximal V-shaped part; 12.2 Distal V-shaped part; 13. Elastic ring; 14. First bending part; 15. Second bending part; 16. Through groove. Detailed implementation manners

[0037] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] In various embodiments of the present invention, "proximal" and "distal" are the relative orientations, relative positions, and directions of elements or actions with respect to each other from the perspective of a doctor using the medical device. Although "proximal" and "distal" are not restrictive in nature, "proximal" generally refers to the end of the medical device that is closer to the doctor during normal operation, while "distal" generally refers to the end that first enters the patient's body and is farther from the doctor.

[0039] Referring to Figures 1-15 , an embodiment of the present invention provides a coil embolization-assisted stent system, including a stent 1 and a delivery system for delivering the stent 1. The stent 1 includes a connected main body section 1.3 and a head section 1.2. The head section 1.2 includes a plurality of diamond-shaped closed loops 1.4 connected in sequence circumferentially. The main body section 1.3 includes a plurality of thick and long rod groups 3 and thin and short rod groups 2 arranged at intervals axially. The thick and long rod groups 3 and the thin and short rod groups 2 are connected by 4 connecting rods 4 arranged circumferentially.

[0040] Specifically, the stent 1 includes a connected main body section 1.3 and a head section 1.2. As Figure 1 shown, the main body section 1.3 is located at the distal end of the head section 1.2. The main body section 1.3 includes a plurality of thick and long rod groups 3 and thin and short rod groups 2 arranged at intervals axially. Each thick and long rod group 3 includes a plurality of thick and long rods. Preferably, each thick and long rod group 3 includes 12 thick and long rods. The 12 thick and long rods are connected end to end circumferentially to form a closed loop. The thin and short rod group 2 includes a plurality of thin and short rods. Preferably, each thin and short rod group 2 includes 24 thin and short rods. The 24 thin and short rods are connected end to end circumferentially to form a closed loop. The radial dimension of the thick and long rod is greater than the radial dimension of the thin and short rod, that is, thicker. The axial dimension of the thick and long rod is greater than the axial dimension of the thin and short rod, that is, longer. Adjacent thick and long rod groups 3 and thin and short rod groups 2 are connected by 4 connecting rods 4. Preferably, the thick and long rods are arranged on the main body section 1.3 at an angle of 30° - 40° with respect to the central axis of the stent 1. The thin and short rods are arranged on the main body section 1.3 at an angle of 30° - 40° with respect to the central axis of the stent 1. The head section 1.2 includes a plurality of diamond-shaped closed loops 1.4 connected in sequence circumferentially. Each side of the plurality of diamond-shaped closed loops 1.4 can preferably be a thin and short rod, that is, four thin and short rods are connected end to end to form a diamond. In an alternative embodiment, the two Vs of the diamond-shaped closed loop 1.4 can be connected by an additional connecting rod 4, that is, at this time the diamond-shaped closed loop 1.4 has six sides instead of four. However, the length of the connecting rod 4 is relatively short, such as less than one-fifth of the length of the thin and short rod, so that the overall shape still approximates a diamond. In practice, this structure has better strength compared to a diamond with four sides. Adjacent thick and long rod groups 3 and thin and short rod groups 2 are connected by connecting rods 4 to enclose a flower-shaped grid unit 6( Figure 2In the case of a medium approximation M shape or a cosine wave structure, the stent 1 includes a plurality of flower-shaped grid units 6, and the flower-shaped grid units 6 are arranged in a cosine wave. In this way, the stent 1 is composed of a plurality of thin and short rod groups 2 and a plurality of thick and long rod groups 3, and the thin and short rod groups 2 and the thick and long rod groups 3 form the flower-shaped grid units 6. The cosine wave arrangement can distribute the grid units more evenly, form a relatively tight structure, and improve the supporting force of the stent 1.

[0041] A coil embolization-assisted stent 1 system provided by an embodiment of the present invention. A plurality of thick and long rod groups 3 and thin and short rod groups 2 are arranged at intervals on the main body section 1.3 of the stent 1. The head section 1.2 includes a plurality of diamond-shaped closed loops 1.4 connected in sequence in the circumferential direction. The diamond-shaped closed loops 1.4 can provide more connection points to help stabilize the delivery system. The adjacent thick and long rod groups 3 and thin and short rod groups 2 are connected by connecting rods 4 to form flower-shaped grid units 6. The flower-shaped grid units 6 are arranged in a cosine wave. The cosine wave arrangement makes the stent 1 form a relatively tight structure, can provide better supporting force, and avoid the stent 1 from collapsing.

[0042] In another embodiment provided by the present invention, flare portions are provided on the distal end of the main body section 1.3 and the proximal end of the head section 1.2, such as a flared opening, preferably, the flare angle of the flare portion is 10°-20°. A plurality of platinum-iridium marker rings 5 are provided on each of the flare portions, preferably, 3 platinum-iridium marker rings 5 are provided. The platinum-iridium marker rings 5 are equally divided in a 120° circumference. The equal division of the platinum-iridium marker rings 5 provides a better imaging effect. The design of the flare portion enables the stent 1 to be accurately anchored after distal release and is not easily displaced.

[0043] In yet another embodiment provided by the present invention, such as Figure 4As shown, the delivery system includes a pusher wire 7 and a delivery section 8 disposed at the distal end of the pusher wire 7. There are three laser markers 7.1 spaced 10 mm apart at the proximal end of the pusher wire 7. The delivery section 8 is located at the distal end of the pusher wire 7. The delivery section 8 includes a proximal support spring 8.1 and a distal support spring 8.2 connected to each other. The proximal support spring 8.1 is located at the proximal end of the distal support spring 8.2. A developing spring 8.3 is disposed at the distal end of the distal support spring 8.2. A proximal limit ring 8.11 is disposed on the proximal support spring 8.1. A distal limit ring 8.22 is disposed on the distal support spring 8.2. The radial dimension of the proximal support spring 8.1 is greater than that of the distal support spring 8.2. The radial dimension of the proximal limit ring 8.11 is greater than that of the distal limit ring 8.22. The use of the stent 1 during the operation includes three processes. One is the transfer process, the second is the delivery process, and the third is the release process. Before the operation starts, the stent 1 needs to be assembled onto the delivery system first. Its assembly process is to assemble the stent 1 into the protection sheath 9 using a crimping tooling, that is, to pre-load the stent into the protection sheath first. At this time, as Figure 5 shown, the crimping tooling is prior art and will not be elaborated. During the use of the intraoperative instrument, the microcatheter 10 is connected to the protection sheath 9 through a Y-valve. The pusher wire 7 is pushed to transfer the stent 1 from the protection sheath 9 into the microcatheter 10. The pusher wire 7 is continuously pushed until the proximal end of the protection sheath 9 reaches the laser marker 7.1, and then the protection sheath 9 is withdrawn. In this way, the transfer process of the stent 1 is achieved. Subsequently, it enters the delivery process. The delivery system is delivered to the area where the aneurysm 11.1 is located. At this time, as Figure 6 shown, when the stent 1 is delivered to the appropriate position, it enters the release process. At this time, the microcatheter 10 is pulled back to release the stent 1, that is, the microcatheter 10 is retracted proximally. The distal end of the stent 1 is first released and thus deployed and anchored at the release point. At this time, as Figure 7 shown, then the microcatheter 10 is continuously retracted until the entire stent 1 is released, as Figure 8 shown. After the stent 1 is completely released, it will cover the aneurysm 11.1. This is the release state of the stent 1. After the stent 1 is completely released, the delivery system and the microcatheter 10 are retracted. In this way, through the cooperation between the delivery system and the stent 1, the stent 1 is sent into the parent vessel 11 and covers the aneurysm 11.1.

[0044] In another embodiment provided by the present invention, as Figures 9-11As shown, the proximal limiting ring 8.11 is provided with a plurality of elastic limiting members 12, such as 3-6, along its circumference. Preferably, the elastic limiting member 12 is a V-shaped structure, and its V-shaped structure includes a middle V-shaped portion and an extension portion extending from each of the two ends of the opening of the V-shaped portion. The V-shaped structure is located on the outer side of the distal support spring 8.2 and its V-shaped portion faces the distal support spring 8.2 with its sharp end (bottom). One of the two extensions is a connecting section and the other is an open section. The connecting section is connected to the proximal limiting ring 8.11. The elastic limiting member 12 includes a tilted state and a limited state. When the conveying system and the stent 1 are not assembled, the elastic limiting member 12 is in a tilted state, such as Figure 9 As shown, its tilted state is also the initial state of the elastic limit member 12. At this time, the elastic limit member 12 is tilted as a whole in the direction away from the distal support spring 8.2. When the stent 1 is assembled in vitro, when the protective sheath 9 is inserted into the distal end of the conveying section 8, the doctor can manually press the open section downward in the direction of the distal support spring 8.2 so that the protective sheath 9 is inserted into the distal end of the conveying section 8. This state is also a limiting state. In this way, the top of the elastic limit member 12 abuts against the inner wall of the protective sheath 9, and the sharp end (bottom) of the V-shaped portion abuts against the stent 1. At this time, the V-shaped portion and the distal limiting ring 8.22 are respectively arranged on the inner and outer sides of the proximal end of the stent to realize the clamping and limiting of the stent 1. After the assembly is completed, when the microcatheter 10 is inserted into the conveying system, the microcatheter 10 is sleeved on the protective sheath 9 When the protective sheath 9 is removed, the elastic limiting member 12 will continue to be squeezed by the microcatheter 10 to maintain it in a limited state. At this time, the top of the elastic limiting member 12 abuts against the inner wall of the microcatheter 10, and the sharp end (bottom) of the V-shaped portion abuts against the bracket 1. In this way, when the bracket 1 is released, the proximal end of the bracket 1 will be squeezed by the elastic limiting member 12 and the distal limiting ring 8.22 to limit the bracket 1 on the conveying section 8. At this time, the microcatheter 10 and the push wire 7 are withdrawn toward the proximal end as a whole, which can drive the bracket 1 to withdraw synchronously, that is, the ability to adjust the bracket by slightly withdrawing is given. As for release, when the microcatheter 10 is completely withdrawn from the position of the bracket 1, the elastic limiting member 12 loses the limit of the microcatheter 10 and enters a tilted state, and the bracket 1 can still be released completely.

[0045] In another embodiment provided by the present invention, Figures 12-14As shown, the elastic limiting member 12 has a double-V configuration, that is, the double-V configuration includes a connected proximal V-shaped portion 12.1 and a distal V-shaped portion 12.2. The depth of the proximal V-shaped portion 12.1 is less than the depth of the distal V-shaped portion 12.2. That is, in the limiting state, the sharp end of the distal V-shaped portion 12.2 abuts against the bracket 1 while the proximal V-shaped portion 12.1 is in a suspended state. That is, at this time, the top of the proximal V-shaped portion 12.1 does not abut against the bracket 1. An elastic ring 13 such as a rubber ring is sleeved on the proximal limiting ring 8.11. The rubber ring has an initial position sleeved on the proximal limiting ring 8.11 and a limiting position sleeved on the proximal V-shaped portion 12.1. A step structure can be provided on the proximal limiting ring 8.11 to limit the elastic ring 13. The open end of the protective sheath 9 bends inward to form a first bending portion 14. The axial cross-section of the first bending portion 14 is a C-shaped configuration, such as Figure 13 As shown, during the assembly process of the bracket 1, the rubber ring is in the initial position. When the sheath 9 is sleeved on the proximal support spring 8.1, the elastic ring 13 cannot be pushed away from the proximal limiting ring 8.11 due to the blocking of the step structure. However, when the protective sheath 9 is pulled towards the distal end, the open end of the first bending portion 14 will contact the elastic ring 13, and its C-shaped configuration can pull the elastic ring 13 towards the distal end. Thus, the elastic ring 13 is driven to the opening of the proximal V-shaped portion 12.1 and is stuck and stays there, that is, it enters the limiting position, such as Figure 15 As shown, thus the elastic ring 13 will be limited at the opening of the proximal V-shaped portion 12.1. At this time, the elastic ring has two functions. One is that its part directly presses against the bracket to complete the limitation. The other is that its whole limits a plurality of elastic limiting members 12 to realize the limitation of the bracket, reducing the moving resistance of the elastic limiting members 12 to the microcatheter 10. That is, at this time, the elastic ring 13 and the distal V-shaped portion 12.2 form a double limitation on the bracket. During the release process of the bracket 1, the distal opening of the microcatheter 10 bends inward to form a second bending portion 15. The second bending portion 15 is a J-shaped configuration. Different from the C-shaped configuration of the protective sheath 9, the end of the second bending portion 15 inclines towards the inner wall of the microcatheter 10 instead of being parallel to the inner wall of the microcatheter 10, such as Figure 14As shown, since the bending degree of the second bending portion 15 is relatively large, when the microcatheter 10 is retracted (moved toward the proximal end), the arc-shaped bending portion of the second bending portion 15 will squeeze and abut against the stent 1 and move proximally along the surface of the stent 1, and the situation where the second bending portion 15 pulls the stent 1 backward will not occur. That is, the bending structure of the second bending portion 15 will avoid hooking the entire stent. A plurality of through grooves 16 are provided through the second bending portion 15 in the circumferential direction, and the number of through grooves 16 should be not less than 10. When the microcatheter 10 is retracted to the elastic limiting member 12, since the end of the second bending portion 15 is lower than the proximal V-shaped portion 12.1, thus, some of the through grooves 16 will be aligned with the region of the elastic ring 13 sleeved on the proximal V-shaped portion 12.1. In this way, the elastic ring 13 will be sleeved into at least one of the through grooves 16. Then the microcatheter 10 continues to move, and its second bending portion 15 hooks the elastic ring 13 out of the elastic limiting member 12. In this way, the limitation on the stent 1 is released. By adding the elastic ring 13, it and the elastic limiting member 12 form a double limitation on the stent 1, so that when the microcatheter 10 and the push wire 7 are retracted proximally as a whole during the release process of the stent 1, it can drive the stent 1 to retract synchronously. In this way, the stent can be slightly retracted and adjusted so that the stent has a better position covering the aneurysm 11.1.

[0046] Only some exemplary embodiments of the present invention have been described by way of illustration above. Undoubtedly, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A coil embolization-assisted stent system, comprising a stent and a delivery system for delivering the stent, characterized in that: The stent includes a connected main section and a head section, the head section includes a plurality of rhombus-shaped closed loops connected in sequence in the circumferential direction, the main section includes a plurality of thick and long rod groups and thin and short rod groups spaced apart in the axial direction, the thick and long rod groups and the thin and short rod groups are connected by four connecting rods arranged in the circumferential direction, the conveying system includes a push wire and a conveying section, the conveying section includes a proximal support spring and a distal support spring, the proximal support spring is provided with a proximal limiting ring, the distal support spring is provided with a distal limiting ring, the stent is located on the conveying section, the radial dimension of the proximal support spring is greater than the radial dimension of the distal support spring, the conveying system also includes a protective sheath, the protective sheath is used for preloading the stent and transferring the stent to a microcatheter, thereby releasing the stent in the tumor-bearing blood vessel, the proximal limiting ring is provided with a plurality of elastic limiting members along its circumference, the elastic limiting member is a V-shaped structure, and its V-shaped structure includes a V-shaped The V-shaped portion is located at the outer side of the distal support spring and the V-shaped portion faces the distal support spring with its sharp end. One of the two extension portions is a connecting section and the other is an open section. The connecting section is connected to the proximal limiting ring. The elastic limiting member includes a tilted state and a limiting state. When the conveying system and the stent have not been assembled, the elastic limiting member is in a tilted state, and the tilted state is also the initial state of the elastic limiting member. At this time, the elastic limiting member is tilted as a whole in a direction away from the distal support spring. When the stent is assembled in vitro, the doctor can manually press the open section downward in the direction of the distal support spring so that the protective sheath is inserted into the distal end of the conveying section. This state is also a limiting state. When the stent is released, the proximal end of the stent will be squeezed by the elastic limiting member and the distal limiting ring to limit the stent on the conveying section. The microcatheter and the push wire are withdrawn toward the proximal end as a whole, which can drive the stent to withdraw synchronously.

2. The coil embolization-assisted stent system according to claim 1, characterized in that: The thick and long rod group includes a plurality of thick and long rods, and the thin and short rod group includes a plurality of thin and short rods.

3. The coil embolization-assisted stent system according to claim 2, characterized in that: The four thin short rods are connected end to end to form a diamond-shaped closed loop.

4. The coil embolization-assisted stent system according to claim 3, characterized in that: The angle formed by the thick and long rod and the central axis is 30°-40°, and the angle formed by the thin and short rod and the central axis is 30°-40°.

5. The coil embolization-assisted stent system according to claim 1, characterized in that: Two adjacent thick and long rod groups and thin and short rod groups are connected by connecting rods to form a flower-shaped grid unit. The bracket includes a plurality of flower-shaped grid units, and the flower-shaped grid units are arranged according to a cosine wave.

6. The coil embolization-assisted stent system according to claim 1, characterized in that: A flared portion is respectively arranged on the distal end of the main body section and the proximal end of the head section, and a plurality of platinum-iridium developing rings are arranged on the flared portion.

7. The coil embolization-assisted stent system according to claim 6, characterized in that: The flaring angle of the flaring portion is 0.1-20°.

Images