Intracranial vein stent and conveying system thereof

Abstract

The invention provides an intracranial vein stent and a delivery system thereof.The intracranial vein stent comprises an inner-layer tube, the inner-layer tube is of a four-cavity structure, namely a first cavity, a second cavity, a third cavity and a fourth cavity, the first cavity is hollow, and the second cavity, the third cavity and the fourth cavity are full; the outer layer pipe is arranged on the inner layer pipe in a sleeving manner; and the woven stent is arranged between the inner-layer tube and the outer-layer tube. The four-cavity structure of the inner-layer tube is arranged, the hollow first cavity can contain a guide wire or a medicine delivery channel, the rigidity of the whole structure is reduced, the filled second cavity, the filled third cavity and the filled fourth cavity achieve staged or local pressure control through independent cavity design, and concentrated stress on the vein wall when the woven stent is unfolded is reduced. The outer-layer tube is sleeved on the inner-layer tube to form a sandwich structure, the braided stent is protected and the preset form of the braided stent is maintained in the conveying process, and meanwhile, the trafficability of the system in tortuous blood vessels is improved through sliding fit between the inner layer and the outer layer. The woven stent is arranged between the inner-layer tube and the outer-layer tube, the non-unfolded state of the woven stent is restrained through interlayer space, controllable release is achieved in combination with the self-expansion characteristic, and mechanical damage of a traditional rigid woven stent to the thin-wall vein is avoided.

Description

Technical Field

[0001] This invention relates to medical devices, specifically an intracranial venous stent and its delivery system. Background Technology

[0002] Currently, non-dedicated carotid artery stents present significant problems in intracranial venous therapy. These stents typically use laser-cut nickel-titanium alloy or cobalt-chromium alloy tubing, which has high radial support and is suitable for muscular vessels such as the carotid artery. However, these stents are too rigid, with an elastic modulus in the range of 80-100 GPa, which can easily lead to venous wall perforation, especially in areas like cerebral veins where the walls are thin and lack muscle and elastic tissue. Using such rigid stents increases the risk of surgical bleeding. In addition, existing carotid artery stent delivery systems mostly use the traditional OTW (overhead thorax) design, with a large outer diameter, making it difficult to pass through small and tortuous intracranial vessels, thus limiting their ability to reach distal lesion sites. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an intracranial venous stent and its delivery system to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an intracranial venous stent and its delivery system comprising: The inner tube has a four-chamber structure, namely a first chamber, a second chamber, a third chamber, and a fourth chamber. The first chamber is hollow, while the second, third, and fourth chambers are filled. An outer tube, which is sleeved on the inner tube; A braided support is disposed between the inner tube and the outer tube.

[0005] In the intracranial venous stent and delivery system provided by the present invention, the braided stent is a self-expanding braided stent, the diameter of the braided filaments of the braided stent ranges from 50μm to 200μm, the pitch of the braided filaments of the braided stent ranges from 0.2mm to 5mm, and the metal coverage of the braided stent ranges from 15% to 40%.

[0006] In an intracranial venous stent and its delivery system provided by the present invention, a first balloon, a second balloon and a third balloon are disposed on the inner tube, and the first balloon, the second balloon and the third balloon are arranged axially and sequentially on the inner tube.

[0007] In an intracranial venous stent and its delivery system provided by the present invention, the length of the first balloon is one-third of the length of the braided stent, the length of the second balloon is one-quarter of the length of the braided stent, and the length of the third balloon is one-quarter of the length of the braided stent.

[0008] In an intracranial venous stent and its delivery system provided by the present invention, the outer tube has a stacked structure at the end away from the first balloon.

[0009] In the intracranial venous stent and delivery system provided by the present invention, the maximum outer diameter of the first balloon, the second balloon and the third balloon in the inflated state is smaller than the inner diameter of the outer tube, and there is an axial gap between the first balloon, the second balloon and the third balloon.

[0010] In the intracranial venous stent and delivery system provided by the present invention, the stacked structure is formed by stacking multiple annular thin sheets in sequence.

[0011] In the intracranial venous stent and its delivery system provided by the present invention, the inner tube and the outer tube are made of polymer materials.

[0012] In an intracranial venous stent and its delivery system provided by the present invention, the surface of the braided stent is provided with a drug coating.

[0013] The intracranial venous stent and its delivery system provided by the present invention also include an operating handle, which is detachably connected to the inner tube and the outer tube.

[0014] The beneficial effects of this invention are: This application employs a four-lumen structure for the inner tube. The hollow first chamber accommodates the guidewire or drug delivery channel, reducing the overall structural rigidity. The filled second, third, and fourth chambers, through independent chamber design, achieve staged or localized pressure control, reducing concentrated stress on the vein wall during stent deployment. The outer tube, fitted over the inner tube, forms a sandwich structure that protects the stent and maintains its pre-positioned shape during delivery. Simultaneously, the sliding cooperation between the inner and outer layers improves the system's permeability in tortuous vessels. The stent, positioned between the inner and outer tubes, utilizes the sandwich space to constrain its undeployed state. Combined with its self-expanding properties, it achieves controlled release, avoiding mechanical damage to thin-walled veins caused by traditional rigid stents. Attached Figure Description

[0015] Figure 1 This is an overall schematic diagram of an intracranial venous stent and its delivery system provided in an embodiment of this application; Figure 2A schematic diagram illustrating the stent release process of an intracranial venous stent and its delivery system provided in this application embodiment: Figure 3 A schematic diagram of the structure of an intracranial venous stent and its delivery system after the braided stent has been deployed, as provided in this application embodiment: Figure 4 A schematic diagram of the balloon distribution of an intracranial venous stent and its delivery system provided in this application embodiment; Figure 5 A schematic diagram of the balloon diameter of an intracranial venous stent and its delivery system provided in this application embodiment; Figure 6 A schematic diagram of the balloon width of an intracranial venous stent and its delivery system provided in this application embodiment; 10. Outer tube; 11. Stacked structure; 20. Inner tube; 21. First balloon; 22. Second balloon; 23. Third balloon; 24. First chamber; 25. Second chamber; 26. Third chamber; 27. Fourth chamber; 30. Braided support frame. Detailed Implementation

[0016] The following description provides numerous specific details to offer a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with this application.

[0017] It should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0018] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0020] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms as defined in commonly used dictionaries shall be interpreted as having a meaning consistent with their meaning in the relevant field and / or the context of this specification, and not as in an ideal or overly formal sense, unless expressly defined herein.

[0021] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of this application, and not all of the embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein. Based on the embodiments of this application described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of this application.

[0022] To address the aforementioned problems, the applicant proposes an intracranial venous stent and its delivery system. Please see [link to relevant documentation]. Figure 1 , Figure 1The present application provides an overall schematic diagram of an intracranial venous stent and its delivery system, which includes: an inner tube 20, an outer tube 10, and a braided stent 30.

[0023] The outer tube 10 is fitted over the inner tube 20, and the braided stent 30 is compressed between the inner tube 20 and the outer tube 10. The inner tube 20 has a four-chamber structure, namely the first chamber 24, the second chamber 25, the third chamber 26, and the fourth chamber 27. The first chamber 24 is hollow. The design of the first chamber 24 as a cavity can reduce the rigidity of the delivery system, improve its flexibility, and ensure that the entire delivery system reaches the lesion location. The second chamber 25, the third chamber 26, and the fourth chamber 27 are filled. The second chamber 25, the third chamber 26, and the fourth chamber 27 serve as filling channels to fill the first balloon 21, the second balloon 22, and the third balloon 23 on the distal inner tube 20 of the system, making them appear bulging, which is used to assist the braided stent 30 in opening and adhering to the wall.

[0024] First, the doctor pushes the delivery system to the lesion site through the first chamber 24. Then, the outer tube 10 is withdrawn to release the braided stent 30. During the withdrawal of the outer tube 10, a certain pressure is applied proximally, causing the balloon structure distal to the inner tube 20 to bulge, assisting in the opening and apposition of the braided stent 30. Its proximal portion is stacked, and the self-expanding braided stent 30 begins to expand and gradually adhere to the vessel wall. If the braided stent 30 fails to fully expand or achieves poor apposition, [further steps can be taken]. The expansion and apposition of the braided stent 30 are assisted through the inflation channels of the second chamber 25, the third chamber 26, and the fourth chamber 27. The first balloon 21, the second balloon 22, and the third balloon 23 are sequentially arranged at the proximal, middle, and distal ends of the braided stent 30 to specifically assist the apposition of the braided stent 30 to the wall at different locations. After the braided stent 30 is fully released, the first balloon 21, the second balloon 22, and the third balloon 23 need to be inflated again to ensure that the braided stent 30 achieves a good fit with the blood vessel wall.

[0025] In the above-described embodiment, this application employs a four-chamber structure for the inner tube 20. The hollow first chamber 24 can accommodate guidewires or drug delivery channels, reducing the overall structural rigidity. The filled second, third, and fourth chambers 27, through independent chamber design, achieve staged or localized pressure control, reducing concentrated stress on the vein wall when the braided stent 30 deploys. The outer tube 10 is fitted onto the inner tube 20 to form a sandwich structure, protecting the braided stent 30 and maintaining its pre-positioned shape during delivery. Simultaneously, the sliding cooperation between the inner and outer layers improves the system's permeability in tortuous blood vessels. The braided stent 30 is positioned between the inner tube 20 and the outer tube 10, utilizing the sandwich space to constrain its undeployed state. Combined with its self-expanding characteristics, it achieves controllable release, avoiding mechanical damage to thin-walled veins caused by traditional rigid braided stents 30.

[0026] In addition, the outer tube 10 is designed with a wrapping and locking structure at the proximal end. The braided support 30 is released by retracting the outer tube 10. Before release, the braided support 30 and the conveying system form a recyclable connection. This means that even after being pushed out 100%, it can still be retrieved into the conduit. The folded part at the proximal end of the outer tube 10 will not increase the length of the conveying system. Specifically, the braided stent 30 can be a self-expanding braided stent 30. The self-expanding braided stent 30 refers to a braided stent 30 structure that achieves autonomous expansion by utilizing the shape memory properties of materials. Specifically, it can be implemented using nickel-titanium alloy as the base material. Its phase transformation temperature is set to be lower than the human body temperature. When in the body environment, the material transforms from the martensitic phase to the austenitic phase, thereby restoring the preset tubular shape. This characteristic allows the braided stent 30 to provide support at the target location through gradual expansion, avoiding mechanical damage to the blood vessel wall caused by instantaneous high pressure release.

[0027] In addition, the diameter of the braided filaments ranges from 50μm to 200μm, the pitch of the braided filaments ranges from 0.2mm to 5mm, and the metal coverage of the braided filaments ranges from 15% to 40%.

[0028] Regarding the parameters of the braided wires, the diameter of the braided wires in the braided stent ranges from 50μm to 200μm. This range ensures that the braided wires have sufficient strength to support the blood vessel while avoiding damage to the vessel due to excessive diameter. Simultaneously, the pitch of the braided wires ranges from 0.2mm to 5mm. This reasonable pitch design allows the stent to form a uniform mesh structure after expansion, effectively blocking thrombi and other substances without excessively hindering normal blood flow. The metal coverage of the braided stent ranges from 15% to 40%. This optimized parameter balances the stent's support performance and biocompatibility, ensuring effective support for the blood vessel while minimizing stimulation and damage to vascular endothelial cells, thus improving the long-term safety and effectiveness of the stent.

[0029] Specifically, after being delivered to the target location, the self-expanding braided stent 30 undergoes a material phase change triggered by body temperature, gradually restoring its preset shape and generating radial support force. Compared to the rigid deployment of traditional rigid braided stents 30, the expansion process of the self-expanding braided stent 30 is time-dependent, with its radial force exhibiting a gradient-increasing characteristic, thus adapting to the thin-layered structure of the vein wall and the anatomical characteristics of lacking elastic tissue. During this process, the contact pressure between the braided stent 30 and the vessel wall is buffered through gradual release, avoiding the risk of vascular perforation caused by localized stress concentration.

[0030] In addition, in this embodiment, a first balloon 21, a second balloon 22 and a third balloon 23 may be provided on the inner tube 20, and the first balloon 21, the second balloon 22 and the third balloon 23 are arranged axially on the inner tube 20 in sequence (from right to left).

[0031] The axial sequential arrangement refers to the three balloons being distributed sequentially along the length of the inner tube 20, specifically using a fixed spacing of 10-15 mm. This arrangement forms physically separated expansion units. The right-to-left arrangement refers to the proximal-to-distal distribution order of the balloon array, specifically using a gradient layout that matches the anatomical direction of intracranial veins. This direction is set in accordance with the blood flow direction and the movement trajectory of the operating handle.

[0032] Specifically, the axial arrangement of three balloons on the inner tube 20 establishes a hierarchical control mechanism. When the delivery system enters a tortuous blood vessel, the balloons can be sequentially inflated from distal to proximal, forming a progressive channel through staged vascular dilation. Each balloon is independently connected to the chamber of the inner tube 20, allowing the operator to achieve local vascular dilation and positioning of the braided stent 30 by selectively applying pressure. The three-balloon structure replaces the traditional monolithic dilation mechanism, transforming a single high-pressure impact into three low-pressure actions, avoiding damage to thin-walled veins due to sudden pressure changes. The spaced arrangement of the balloon array disperses the dilation force across three independent areas, reducing pressure per unit area while maintaining adaptability to vascular bends.

[0033] like Figure 4 As shown. The first balloon 21, the second balloon 22, and the third balloon 23 are distributed at the far end of the overall structure of the conveying system. The first balloon 21 is distributed at the proximal end of the braided support 30, the second balloon 22 is distributed at the middle of the braided support 30, and the third balloon 23 is distributed at the far end of the braided support 30. They are used to assist the opening and wall contact of the braided support 30 respectively. The braided support 30 can be opened and wall contacted without adjusting the position of the conveying system.

[0034] Furthermore, the number and distribution of balloons can be adjusted according to actual needs, such as increasing or decreasing the number of balloons. The configuration of the balloon system can be flexibly adjusted according to lesion characteristics and treatment requirements. Specific options are as follows: Option 1 adopts a single-balloon modular design, with the balloon centrally positioned in the middle of the braided stent 30. The balloon length covers 60%~80% of the working section of the braided stent 30, and precise wall apposition assistance is achieved through graded pressure control (4~12 atm). This design simplifies the operation process and is suitable for short lesions or straight vessel segments. Option 2 adopts a dual-balloon synergistic layout. The proximal and distal balloons form a dynamic support force field through alternating inflation (pressure difference ≤2 atm), effectively overcoming poor wall apposition caused by vessel tortuosity or calcification. The dual-balloon design can improve the wall apposition uniformity of the braided stent 30 in complex lesions by up to 35% (clinical data), while reducing the risk of marginal dissection, providing technical support for personalized interventional treatment.

[0035] refer to Figure 5 The length of the first balloon 21 is one-third the length of the braided stent 30, the length of the second balloon 22 is one-quarter the length of the braided stent 30, and the length of the third balloon 23 is one-quarter the length of the braided stent 30. For example, the length of the braided stent 30 is L, the length of the balloons is L1, L2, and L3, where L1 = 1 / 3L, L2 = 1 / 4L, and L3 = 1 / 4L. This helps the proximal, middle, and distal ends of the braided stent 30 to better adhere to the wall.

[0036] The first balloon 21 refers to the basic expansion unit located at the proximal end, which can be implemented using a segmented polymer balloon, with its length proportions configured to establish the initial support region. The second balloon 22 and the third balloon 23 refer to independent control units located in the middle and distal ends, respectively, which can be implemented using a variable-diameter folding structure, arranged axially at intervals to form a graded expansion zone.

[0037] Specifically, the length ratio of the three balloons forms a proximal concentrated distribution pattern, with the proximal balloon occupying one-third of the length area and providing the main support during the initial deployment of the braided stent 30. The mid- and distal balloons each occupy one-quarter of the length area, maintaining an independent working state during advancement. When the braided stent 30 reaches the tortuous vein, the mid- and distal balloons can achieve phased sequential expansion. This design results in a gradient distribution of the contact area between the balloon and the vein wall, with the area larger at the front and smaller at the back. While ensuring overall support, the local pressure in the distal area is dispersed, avoiding stress concentration caused by a single long balloon in the tortuous segment of the vessel.

[0038] In addition, the proximal end of the outer tube 10 is specially designed with a wrap-around locking structure, which allows the braided support 30 to be released by retracting the outer tube 10. Before release, the braided support 30 is fixed to the delivery system via a retractable connection, ensuring that the braided support 30 can be safely retracted into the catheter even after it has been fully pushed to the target position. It is worth noting that the folding design at the proximal end of the outer tube 10 does not increase the overall length of the delivery system.

[0039] When the retraction operation is performed, the end of the outer tube 10 furthest from the first balloon 21 adopts a stacked structure design. This stacked structure is composed of multiple annular thin sheets stacked sequentially along the axial direction to form a deformable component. Specifically, it is manufactured by using nickel-titanium alloy sheets that are precision-cut by laser and then assembled through a stacking process. This structure, through the gap design between the annular thin sheets, allows for localized and controllable folding of the end during the push-out process, thereby significantly reducing the overall rigidity of the delivery system end and improving the compliance and passability of the device.

[0040] Specifically, when the delivery system traverses the tortuous path of an intracranial vein, the gaps between the annular sheets of the stacked structure 11 allow each sheet to undergo independent axial compression or radial deflection. When the end of the outer tube 10 contacts the bend in the blood vessel, the concentrated stress applied to the tube wall is decomposed into local folds of multiple deformation units, changing the contact mode between the tube and the inner wall of the blood vessel from surface contact to multi-point discrete contact. This discrete contact mode reduces the peak pressure exerted by the tube on the blood vessel wall, while consuming part of the pushing force through sliding friction between the sheets, avoiding the accumulation of shear stress caused by the inability of the rigid tube to deform.

[0041] Furthermore, the maximum outer diameter of the first balloon 21, the second balloon 22, and the third balloon 23 in their inflated state is smaller than the inner diameter of the outer tube 10, and there is an axial gap between the first balloon 21, the second balloon 22, and the third balloon 23. For example, refer to... Figure 6 The braided stent 30 is deployed onto the inner wall of the blood vessel, where the inner diameter of the vessel is D5, the diameter of the braided stent 30 is D1, the maximum height of the first balloon 21, the second balloon 22, and the third balloon 23 is D1~D3, and the diameter of the inner tube 20 is D4. The balloon structure helps the braided stent 30 adhere to the vessel wall, i.e., D4 + 2D1 = D. Because the inner diameter of the distal vessel is smaller than that of the proximal vessel, the maximum height of the first balloon 21, the second balloon 22, and the third balloon 23 is D3. <D2<D1。

[0042] The maximum outer diameter in the inflated state refers to the maximum radial dimension of the balloon when it is fully inflated. This can be achieved by controlling the elastic modulus of the balloon material or by using a folded structure. This dimensional limitation ensures that the balloon does not generate frictional resistance with the inner wall of the outer tube 10 when moving within the lumen. The axial spacing refers to the straight-line distance between the center points of adjacent balloons. This can be achieved by setting spacer rings between balloons or adjusting the position of the balloon fixing points. This spacing forms a discontinuous contact area, resulting in a phased contact mechanical distribution during balloon inflation.

[0043] Specifically, when the balloon is uninflated, its outer diameter allows the entire delivery system to move smoothly within the blood vessel. During inflation, the balloon's outer diameter is limited by the inner diameter of the outer tubing 10, preventing over-inflation and damage to the vessel wall. The axial spacing creates a gradient pressure distribution among the three balloons during inflation. As the outer tubing 10 retracts to release the braided stent 30, the balloons contact the vessel wall sequentially according to their spacing, and the braided stent 30 gradually unfolds. This staged release mechanism reduces the instantaneous pressure impact on thin-walled veins while minimizing frictional resistance between the delivery system and the blood vessel.

[0044] In addition, the inner tube 20 and the outer tube 10 are made of polymer materials.

[0045] The polymer material refers to a deformable and biocompatible polymer material, specifically polyurethane, nylon, or polytetrafluoroethylene. These materials reduce the overall rigidity of the delivery system through the flexibility of their molecular chains. The inner tube 20 refers to the core catheter that wraps around the braided stent 30 to form a multi-lumen structure. It can be achieved through extrusion molding, and its polymer properties can disperse localized stress generated during intravascular delivery. The outer tube 10 refers to the sheath that covers the inner tube 20, forming a restraint layer. It can be achieved through heat-shrink molding, and its polymer material allows for axial bending deformation while maintaining structural integrity.

[0046] Specifically, by replacing traditional metal materials with polymer materials, the inner tube 20 and outer tube 10 undergo elastic deformation rather than rigid displacement during intravascular delivery. When the delivery system passes through the tortuous anatomical structure of intracranial veins, the tube material absorbs bending stress through the extension and retraction of molecular chains, avoiding tube wall penetration caused by excessively high elastic modulus. The low coefficient of friction of the polymer material further reduces contact damage with the vascular intima, while the synergistic deformation capability of the multi-layered tube structure allows the braided stent 30 to conform more closely to the natural curvature of the vein during release.

[0047] A drug coating can also be applied to the surface of the braided scaffold 30. This drug coating is a functional covering layer adhered to the surface of the braided scaffold 30. Specifically, polylactic acid-glycolic acid copolymer or polyurethane can be used as the carrier material, and the antiproliferative drug is bonded to the carrier to form the coating through electrospinning or impregnation. This coating degrades upon contact with body fluids, enabling controlled drug release.

[0048] Antiproliferative drugs are compounds that can inhibit excessive cell proliferation. Specifically, they can use paclitaxel or rapamycin as active ingredients to exert their effects by interfering with the cell cycle or inhibiting the secretion of inflammatory factors.

[0049] Specifically, after the braided stent 30 is implanted into an intracranial vein, the drug coating gradually releases anti-proliferative drugs into the intravascular environment, inhibiting the abnormal proliferation of vascular endothelial cells. Because the vein wall lacks a muscular layer and elastic tissue, the drug covers the contact area between the braided stent 30 and the vein wall through a local sustained-release mechanism, reducing inflammatory responses caused by mechanical stimulation. Simultaneously, the drug release cycle matches the endothelial repair process, with rapid release in the initial stage of stent 30 deployment to inhibit acute thrombosis, followed by continuous release to maintain vascular patency.

[0050] In some specific embodiments, the drug coating can be designed as a multilayer structure, with the inner layer containing the anticoagulant heparin sodium to inhibit platelet aggregation, and the outer layer loaded with rapamycin to control smooth muscle cell migration. The molecular weight of the carrier material can be adjusted to match the release rate of different drugs.

[0051] To facilitate operation by medical staff, an operating handle can also be provided, which can be detachably connected to the inner tube 20 and the outer tube 10.

[0052] The operating handle is a device used to control the movement of the inner tube 20 and the outer tube 10. Specifically, it can be implemented using a mechanical interface with a locking buckle. Its function is to provide a control mode for independent or coordinated operation of the two tubes. The detachable connection refers to a structure that allows the handle to be physically separated from the inner tube 20 and the outer tube 10. Specifically, it can be implemented using a threaded connection or a slide rail plug-in structure. Its function is to realize the modular design of the delivery system, which facilitates the adjustment of the system configuration according to the path conditions during the operation.

[0053] Specifically, the operating handle is detachably connected to the inner tube 20 and outer tube 10 to form an integrated delivery system. When entering narrow or tortuous intracranial vessels, the relative positions of the two tubes can be adjusted by separating the handle, or one tube can be operated individually, thereby improving the system's path-following capability. Once the braided stent 30 reaches the target position, the operating handle can be quickly detached to reduce the system's outer diameter and avoid compression damage to the vein wall due to excessive space occupation. This solution decomposes the traditional integrated delivery system into independently operable components through a modular structure, retaining the force transmission function while reducing the overall rigidity of the system.

[0054] Specifically: The physician pushes the delivery system to the lesion site through the first chamber 24, and then withdraws the outer tube 10 to release the braided stent 30. During the withdrawal of the outer tube 10, a certain pressure is applied proximally to cause the balloon structure distal to the inner tube 20 to bulge, which assists in the opening and apposition of the braided stent 30 to the vessel wall. Its proximal portion is stacked, and the self-expanding braided stent 30 begins to expand and gradually adhere to the inner wall of the blood vessel. If the braided stent 30 fails to fully deploy or achieves poor adhesion to the vessel wall, the deployment and adhesion of the braided stent 30 can be assisted through the inflation channels of the second chamber 25, the third chamber 26, and the fourth chamber 27. The first balloon 21, the second balloon 22, and the third balloon 23 are sequentially positioned at the proximal, middle, and distal ends of the braided stent 30 to specifically assist in the adhesion of the braided stent 30 to different parts of the vessel wall. After the braided stent 30 is fully deployed, the first balloon 21, the second balloon 22, and the third balloon 23 need to be inflated again to ensure that the braided stent 30 achieves a good adhesion to the vessel wall.

[0055] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0056] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0057] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0058] Similarly, it should be understood that, in order to simplify this application and aid in understanding one or more aspects of the application, various features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, the point of application is that the corresponding technical problem can be solved with fewer features than all of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0059] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or elements of any method or apparatus so disclosed may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0060] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0061] It should be noted that the above embodiments are illustrative of this application and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0062] The above description is merely a specific embodiment or illustration of the embodiments of this application. The scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. The scope of protection of this application shall be determined by the scope of the claims.

Claims

1. An intracranial venous stent and its delivery system, characterized in that, include: The inner tube has a four-chamber structure, namely a first chamber, a second chamber, a third chamber, and a fourth chamber. The first chamber is hollow, while the second, third, and fourth chambers are filled. An outer tube, which is sleeved on the inner tube; A braided support is disposed between the inner tube and the outer tube.

2. The intracranial venous stent and its delivery system according to claim 1, characterized in that, The braided support is a self-expanding braided support. The diameter of the braided filaments ranges from 50μm to 200μm, the pitch of the braided filaments ranges from 0.2mm to 5mm, and the metal coverage of the braided support ranges from 15% to 40%.

3. The intracranial venous stent and its delivery system according to claim 1, characterized in that, The inner tube is provided with a first balloon, a second balloon, and a third balloon, which are arranged axially and sequentially on the inner tube (from right to left).

4. The intracranial venous stent and its delivery system according to claim 3, characterized in that, The length of the first balloon is one-third of the length of the woven stent, the length of the second balloon is one-quarter of the length of the woven stent, and the length of the third balloon is one-quarter of the length of the woven stent.

5. An intracranial venous stent and its delivery system according to claim 3, characterized in that, The outer tube has a stacked structure at the end away from the first balloon.

6. The intracranial venous stent and its delivery system according to claim 4, characterized in that, The maximum outer diameter of the first, second, and third balloons in their inflated state is smaller than the inner diameter of the outer tube, and there is an axial gap between the first, second, and third balloons.

7. An intracranial venous stent and its delivery system according to claim 5, characterized in that, The stacked structure is composed of multiple annular thin sheets stacked sequentially.

8. The intracranial venous stent and its delivery system according to claim 1, characterized in that, The inner tube and the outer tube are made of polymer materials.

9. An intracranial venous stent and its delivery system according to claim 1, characterized in that, The surface of the braided scaffold is coated with a drug.

10. An intracranial venous stent and its delivery system according to claim 1, characterized in that, It also includes an operating handle, which is detachably connected to the inner tube and the outer tube.

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