Blood flow diverting devices and blood flow diverting systems

Abstract

The application provides a blood flow guiding device and a blood flow guiding system. The blood flow guiding device comprises a stent body formed by interlacing a plurality of braided wires; the stent body has mesh holes; the stent body comprises a distal end region, a middle region and a proximal end region; the mesh hole density of the distal end region and the proximal end region is lower than that of the middle region; the length of the end part of the braided wire which does not form the mesh hole in the distal end region and the proximal end region is smaller than the size of the mesh hole in the distal end region and the proximal end region, so that the radial force and the wall adhesion of the middle region of the stent body are ensured, the radial force of the distal end region and the proximal end region of the stent body to the microcatheter is reduced, the friction between the distal end region and the proximal end region of the stent body and the inner wall of the microcatheter is reduced, the conveying smoothness and the control precision of the stent body in the microcatheter are improved, and the smoothness of the stent body in the recovery process is improved.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and more specifically, to a blood flow diversion device and a blood flow diversion system. Background Technology

[0002] Intracranial aneurysms are abnormal, tumor-like protrusions that occur locally in cerebral arteries under the influence of various factors, and are a relatively common clinical condition. Rupture of an intracranial aneurysm can lead to subarachnoid hemorrhage, with high mortality and disability rates. Currently, the main treatment for anterior intracranial aneurysms is interventional therapy involving the implantation of a dense mesh stent. This method utilizes the dense metal wires of the stent to block blood flow from the parent artery into the aneurysm, accelerating thrombus formation within the aneurysm and ultimately causing occlusion and achieving a cure. The purpose of healing.

[0003] However, during the delivery of the mesh stent, there is significant friction between the distal end of the mesh stent and the inner wall of the microcatheter, which not only affects the smoothness of delivery but may also damage the inner wall of the microcatheter or the distal structure of the mesh stent. During the retrieval of the mesh stent, there is also significant friction between its proximal end and the inner wall of the microcatheter, leading to difficulties in retrieval, prolonged operation time, and increased surgical risks. Summary of the Invention

[0004] This application addresses the shortcomings of existing methods by proposing a blood flow guiding device and system to solve the technical problem that, during the delivery or retrieval of the mesh stent, there is significant friction between the distal or proximal end of the mesh stent and the inner wall of the microcatheter, resulting in high delivery and retrieval resistance.

[0005] In a first aspect, embodiments of this application provide a blood flow guiding device, comprising: a support body formed by interlacing multiple braided filaments; the support body having mesh openings; the support body including a distal region, an intermediate region, and a proximal region; the mesh density of the distal region and the proximal region is lower than the mesh density of the intermediate region, and is configured such that the length of the ends of the braided filaments in the distal region and the proximal region where the mesh openings are not formed is smaller than the size of the mesh openings in the distal region and the proximal region.

[0006] In some embodiments, the mesh openings in the distal and proximal regions are rhomboid in the axial plane of the support body.

[0007] In some embodiments, the blood flow diversion device further includes at least one of the following: The number of braiding threads includes at least one of the following: 32, 36, 40, 44, 48, 64, or 72. The diameter of the braided yarns ranges from 0.0006 to 0.003 inches.

[0008] Secondly, embodiments of this application provide a blood flow guiding system, including: a delivery device and a blood flow guiding device as described in any of the above embodiments; the delivery device is used to deliver the blood flow guiding device.

[0009] In some embodiments, the conveying device includes: a core wire, and a first marking ring, a distal end protector, a second marking ring, a friction pad, a third marking ring, and a proximal end protector arranged sequentially from the distal end to the proximal end of the core wire; With the stent body of the blood flow guiding device sleeved on the outer periphery of the distal end of the core wire, the second marking ring, the friction pad, and the third marking ring are located inside the stent body.

[0010] In some embodiments, the distal protective member is sleeved on the outer periphery of the distal end of the core wire and is fixedly connected to the core wire; when the stent body of the blood flow guiding device is sleeved on the outer periphery of the distal end of the core wire, the distal protective member is located between the first marking ring and the stent body.

[0011] In some embodiments, the distal protective member includes a fixed portion and an extended portion connected together; the fixed portion is sleeved on the outer periphery of the distal end of the core wire and is fixedly connected to the core wire; the extended portion is configured to extend or retract depending on the rotation direction of the core wire, and in the extended state, the maximum dimension of the extended portion along the radial direction of the support body is greater than the radial dimension of the support body.

[0012] In some embodiments, the friction pad is located between the second marking ring and the third marking ring, and the friction pad is movably sleeved on the outer periphery of the core wire; both the second marking ring and the third marking ring are sleeved on the outer periphery of the core wire and are fixedly connected to the core wire.

[0013] In some embodiments, the blood flow diversion system further includes a microcatheter; the delivery device is movably disposed within the microcatheter.

[0014] In some embodiments, the proximal protective member is sleeved on the outer periphery of the distal end of the core wire and is fixedly connected to the core wire; with the support body sleeved on the outer periphery of the distal end of the core wire, the proximal protective member is located on the proximal end of the support body near the proximal end of the core wire. With the stent body recovered, at least a portion of the proximal protection element is located between the proximal end of the stent body and the inner wall of the microcatheter.

[0015] The beneficial technical effects of the technical solutions provided in this application include: In this embodiment, multiple braided filaments are interwoven to form a cylindrical stent body. The mesh density (i.e., the number of mesh holes per unit area) of the distal and proximal regions of the stent body is lower than that of the middle region. This results in the radial support force of the distal and proximal regions of the stent body being less than that of the middle region. This ensures the radial support force and wall adhesion of the middle region of the stent body while reducing the radial force exerted on the microcatheter by the distal and proximal regions of the stent body. Consequently, the friction between the distal region of the stent body and the inner wall of the microcatheter, as well as between the proximal region and the inner wall of the microcatheter, is reduced. This improves the smoothness of stent delivery and control precision within the microcatheter, and enhances the smoothness of stent retrieval.

[0016] Furthermore, during the delivery of the stent body, the distal region of the stent body expands into a trumpet shape. In the distal region of the stent body, the ends of the excess braided filaments that do not form a mesh are cut short to prevent the ends of the braided filaments that do not form a mesh from piercing the inner wall of the microcatheter. This reduces the friction between the distal region of the stent body and the inner wall of the microcatheter, thereby improving the smoothness of the stent body delivery and the control precision within the microcatheter.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of a blood flow diversion system provided in an embodiment of this application; Figure 2 This is a schematic diagram of the process by which a delivery device transports a blood flow guiding device to a predetermined position and retracts a remote protective component in a blood flow guiding system provided in an embodiment of this application. Figure 3 This application provides a schematic diagram of a blood flow guiding system in which the blood flow guiding device is detached from the delivery device. Figure 4 A schematic diagram of the structure of a blood flow guiding device in a blood flow guiding system provided in this application embodiment; Figure 5 This is a schematic diagram of the structure of a blood flow guiding device provided in an embodiment of this application; Figure 6 A schematic flowchart illustrating a method for manufacturing a blood flow diversion device according to an embodiment of this application; Figure 7 A schematic diagram showing the implantation of an untreated scaffold body into the device and its removal from the device; Figure 8 This is a schematic diagram showing the surface-treated scaffold body, as provided in this embodiment, after being implanted into the body and removed from the body. Figure label: 1-Flow diverting device; 11-Stent body; 111-Braided wire; 112-Mesh; 113-Distal region; 114-Intermediate region; 115-Proximal region; 2-Conveying device; 21-Core wire; 22-First marking ring; 23-Distal protection element; 25-Friction pad; 26-Third marking ring; 27-Proximal protection element; 28-Microcatheter; 29-Fourth marking ring. Detailed Implementation

[0019] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0020] Those skilled in the art will understand that, unless specifically stated otherwise, the terms "described" and "the" as used herein may also include plural forms. It should be further understood that the term "comprising" as used in the specification of this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by the art. The term "and / or" as used herein refers to at least one of the items defined by the term; for example, "A and / or B" can be implemented as "A," or as "B," or as "A and B."

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0022] Intracranial aneurysms are abnormal, tumor-like protrusions that occur locally in cerebral arteries under the influence of various factors, and are a relatively common clinical condition. Rupture of an intracranial aneurysm can lead to subarachnoid hemorrhage, with high mortality and disability rates. Currently, the main treatment for anterior intracranial aneurysms is interventional therapy involving the implantation of a dense mesh stent. This method utilizes the dense metal wires of the stent to block the shunting of blood from the parent artery into the aneurysm, accelerating thrombus formation within the aneurysm, and ultimately causing aneurysm occlusion and achieving a cure.

[0023] However, during the delivery of the mesh stent, there is significant friction between the distal end of the mesh stent and the inner wall of the microcatheter, which not only affects the smoothness of delivery but may also damage the inner wall of the microcatheter or the distal structure of the mesh stent. During the retrieval of the mesh stent, there is also significant friction between its proximal end and the inner wall of the microcatheter, leading to difficulties in retrieval, prolonged operation time, and increased surgical risks.

[0024] The technical solution of this application and how it solves the above-mentioned technical problems are described in detail below with specific embodiments. It should be noted that the following embodiments can be referenced, borrowed, or combined with each other, and the same terms, similar features, and similar implementation steps in different embodiments will not be described again.

[0025] This application provides a blood flow guiding device 1, such as... Figures 1 to 5 As shown, the blood flow guiding device 1 includes: a stent body 11 formed by interlacing multiple braided filaments 111; the stent body 11 has mesh openings 112; the stent body 11 includes a distal region 113, an intermediate region 114 and a proximal region 115; the mesh density of the distal region 113 and the proximal region 115 is lower than that of the intermediate region 114, and is configured such that the length of the ends of the braided filaments 111 in the distal region 113 and the proximal region 115 that do not form mesh openings 112 is smaller than the size of the mesh openings 112 in the distal region 113 and the proximal region 115.

[0026] In this embodiment, multiple braided filaments 111 are interwoven to form a cylindrical stent body 11. The mesh density (i.e., the number of mesh holes 112 per unit area) of the distal region 113 and proximal region 115 of the stent body 11 is lower than that of the middle region 114 of the stent body 11. This results in the radial support force of the distal region 113 and proximal region 115 of the stent body 11 being less than that of the middle region 114 of the stent body 11. This ensures the radial support force and wall adhesion of the middle region 114 of the stent body 11 while reducing the radial force exerted by the distal region 113 and proximal region 115 of the stent body 11 on the microcatheter 28. This reduces the friction between the distal region 113 and the inner wall of the microcatheter 28, as well as between the proximal region 115 and the inner wall of the microcatheter 28. This improves the smoothness of the stent body 11's delivery and the control precision within the microcatheter 28, and also improves the smoothness of the stent body 11 during the retrieval process.

[0027] Furthermore, during the delivery of the stent body 11, the distal region 113 of the stent body 11 expands into a trumpet shape. In the distal region 113 of the stent body 11, the ends of the excess braided filaments 111 that do not form mesh 112 are cut short to prevent the ends of the braided filaments 111 that do not form mesh 112 from piercing the inner wall of the microcatheter 28. This reduces the friction between the distal region 113 of the stent body 11 and the inner wall of the microcatheter 28, thereby improving the smoothness of the delivery and the control precision of the stent body 11 within the microcatheter 28.

[0028] Similarly, during the retrieval process of the stent body 11, the proximal region 115 of the stent body 11 expands into a trumpet shape. In the proximal region 115 of the stent body 11, the ends of the excess braided filaments 111 that do not form mesh 112 are cut short to prevent the ends of the braided filaments 111 that do not form mesh 112 from piercing the inner wall of the microcatheter 28. This reduces the friction between the proximal region 115 of the stent body 11 and the inner wall of the microcatheter 28, thereby improving the smoothness of the stent body 11 during the retrieval process.

[0029] In some embodiments, in the distal region 113 and the proximal region 115, the length of the end of the braided filament 111 that does not form a mesh 112 is less than the length of the mesh 112 in the distal region 113 and the proximal region 115 or the size of the mesh 112 along the radial direction of the support body 11.

[0030] Alternatively, in one possible implementation of this application, such as Figure 5 As shown, in the axial plane of the support body 11, the mesh 112 of the distal region 113 and the proximal region 115 is rhomboid.

[0031] In this embodiment, the long axis of the mesh 112 of the distal region 113 and the proximal region 115 is parallel to the axial direction of the stent body 11, making it easier for the distal region 113 and the proximal region 115 to undergo controllable deformation under axial force. This results in better flexibility and compliance when passing through tortuous blood vessel segments. At the same time, it can reduce the radial force exerted by the distal region 113 and the proximal region 115 on the inner wall of the microcatheter 28, thereby improving the smoothness, stability and safety of the stent body 11 during delivery and retrieval.

[0032] Optionally, in some embodiments, the angle between the major axis of the mesh 112 of the distal region 113 and the proximal region 115 and the axial direction of the support body 11 is an acute angle.

[0033] Optionally, in this embodiment, along the axial direction of the stent body 11, the distal region 113 is a region with a length of 1 mm from the distal end of the stent body 11; the proximal region 115 is a region with a length of 1 mm from the proximal end of the stent body 11. The size design of the distal region 113 and the proximal region 115 can effectively reduce the friction between the distal region 113 and the proximal region 115 of the stent body 11 and the inner wall of the microcatheter 28, while taking into account the radial support force and wall adhesion of the intermediate region 114, thereby improving the overall performance of delivery and retrieval.

[0034] Alternatively, in one possible implementation of this application, such as Figure 5 As shown, the blood flow diversion device further includes: the number of braided filaments 111 includes at least one of 32, 36, 40, 44, 48, 64, or 72; the diameter of the braided filaments 111 includes 0.0006-0.003 inches. The blood flow diversion device can be delivered within a microcatheter 28 with an inner diameter of 0.017 inches.

[0035] In related technologies, a stent body formed by interlacing at least 64 braided filaments is used. The high mesh density of the stent body leads to risks such as branch vessel occlusion, ischemic stroke, and neurological damage when using this stent body for interventional treatment of anterior intracranial aneurysms. If only the mesh density of the stent body is reduced, the radial support of the stent body will be insufficient, and the stent body will not be able to fully deploy in tortuous or bifurcated vessels, resulting in poor wall apposition and incomplete coverage of the aneurysm neck. This not only affects the aneurysm occlusion effect but may also lead to serious complications such as thrombosis and distal embolism due to the gap between the stent body and the vessel wall.

[0036] In this embodiment, the support body 11 is a self-expanding support body.

[0037] Optionally, in one specific embodiment of this application, the stent body 11 is made of 40 braided wires 111, which are braided by a special 40-wire braiding machine. The braided wires are relatively thick metal wires, and the diameter of the braided wires 111 includes 0.0012-0.0015 inches. This makes the mesh density on the stent body 11 moderate, taking into account both radial support and wall adhesion. This ensures that the stent body 11 can be stably deployed and closely adhered to the wall in tortuous or bifurcated blood vessels, thereby achieving complete coverage of the aneurysm neck and efficient blood flow guidance. At the same time, it can effectively avoid obstruction of branch blood vessels, reducing the risk of ischemic stroke, neurological damage, and stenosis within the stent body.

[0038] Optionally, in this embodiment, the porosity of the stent body 11 is 65%-75%, with 15-20 pores per square millimeter of stent area; this ensures both blood flow guidance and avoids obstruction of branch vessels. Porosity refers to the ratio of the mesh area per unit area to the total surface area of ​​the stent body 11. The diameter of the stent body 11 is not less than 1.75 mm, and the length of the stent body 11 (the dimension along the axial direction of the stent body 11) ranges from 10-30 mm to accommodate small blood vessels with a diameter less than 2 mm.

[0039] Optionally, in some embodiments, the 40 braided filaments 111 are composed of a portion of cobalt-chromium alloy braided filaments 111 and a portion of platinum-tungsten alloy braided filaments 111 interwoven, so that the braided support body 11 takes into account both radial support force and development performance.

[0040] Optionally, in some embodiments, all 40 braided filaments 111 are nickel-titanium alloy wires. It should be noted that, in the embodiments of this application, the material selection for the braided filaments 111 is not limited to the above examples, and other medical metal materials with biocompatibility, mechanical property matching, and radiometric properties can be flexibly selected according to clinical needs.

[0041] Based on the same inventive concept, this application provides a method for manufacturing a blood flow guiding device, used to manufacture any of the blood flow guiding devices described in the above embodiments, such as... Figure 6 As shown, the manufacturing method includes the following steps: S101: Multiple braided filaments 111 are interwoven to form a tubular structure with mesh 112. The tubular structure includes a distal region 113, a middle region 114 and a proximal region 115. The ends of the braided filaments 111 in the distal region 113 and the proximal region 115 that do not form mesh 112 are cut short.

[0042] S102: The surface of the cylindrical structure is processed to obtain the support body 11; the mesh density of the distal region 113 and the proximal region 115 of the support body 11 is lower than that of the middle region 114; in the distal region 113 and the proximal region 115, the length of the end of the braided filament 111 that does not form a mesh 112 is smaller than the size of the mesh 112 in the distal region 113 and the proximal region 115.

[0043] In this embodiment, multiple braided filaments 111 are interwoven to form a cylindrical stent body 11. The mesh density (i.e., the number of mesh holes 112 per unit area) of the distal region 113 and proximal region 115 of the stent body 11 is lower than that of the middle region 114 of the stent body 11. This results in the radial support force of the distal region 113 and proximal region 115 of the stent body 11 being less than that of the middle region 114 of the stent body 11. This ensures the radial support force and wall adhesion of the middle region 114 of the stent body 11 while reducing the radial force exerted by the distal region 113 and proximal region 115 of the stent body 11 on the microcatheter 28. This reduces the friction between the distal region 113 and the inner wall of the microcatheter 28, as well as between the proximal region 115 and the inner wall of the microcatheter 28. This improves the smoothness of the stent body 11's delivery and the control precision within the microcatheter 28, and also improves the smoothness of the stent body 11 during the retrieval process.

[0044] Furthermore, during the delivery of the stent body 11, the distal region 113 of the stent body 11 expands into a trumpet shape. In the distal region 113 of the stent body 11, the ends of the excess braided filaments 111 that do not form mesh 112 are cut short to prevent the ends of the braided filaments 111 that do not form mesh 112 from piercing the inner wall of the microcatheter 28. This reduces the friction between the distal region 113 of the stent body 11 and the inner wall of the microcatheter 28, thereby improving the smoothness of the delivery and the control precision of the stent body 11 within the microcatheter 28.

[0045] Similarly, during the retrieval process of the stent body 11, the proximal region 115 of the stent body 11 expands into a trumpet shape. In the proximal region 115 of the stent body 11, the ends of the excess braided filaments 111 that do not form mesh 112 are cut short to prevent the ends of the braided filaments 111 that do not form mesh 112 from piercing the inner wall of the microcatheter 28. This reduces the friction between the proximal region 115 of the stent body 11 and the inner wall of the microcatheter 28, thereby improving the smoothness of the stent body 11 during the retrieval process.

[0046] Optionally, in one possible embodiment of this application, step S102 above, which processes the surface of the cylindrical structure to obtain the support body 11, includes: The surface of the cylindrical structure is treated with a mixed oxide layer.

[0047] The surface of the cylindrical structure is polished.

[0048] A passivation film is formed on the surface of the cylindrical structure.

[0049] A phosphoric acid choline antithrombotic coating is formed on the passivation membrane to obtain the stent body 11.

[0050] In this embodiment, firstly, the surface of the cylindrical structure is treated with a mixed oxide layer to remove the uncontrollable, thick, and mixed-component oxide layer. Next, the surface of the cylindrical structure is electrochemically polished to optimize its surface roughness. Further, a uniform passivation film is formed on the surface of the cylindrical structure, giving the stent body 11 made from the cylindrical structure good biocompatibility and corrosion resistance. Finally, a phosphocholine antithrombotic coating is formed on the passivation film to initially improve the biocompatibility of the stent body 11. This achieves multi-level, multi-angle comprehensive treatment of the surface of the stent body 11, thereby comprehensively optimizing the physicochemical properties of the surface material of the stent body 11. Moreover, the synergistic effect of this series of surface treatment processes results in the braided filaments 111 forming the stent body 11 having high smoothness and excellent corrosion resistance, so that the stent body 11 is not recognized as a foreign body by the body during implantation, thus avoiding triggering inflammatory or abnormal coagulation reactions. Moreover, in this embodiment, the combination of the structural design of the stent body 11 and the surface treatment of the stent body 11 can significantly reduce the potential for thrombus formation on the surface of the stent body 11, thereby improving the safety and stability of the stent body 11 in clinical use.

[0051] also, Figure 7 This is a schematic diagram of a stent body implanted into the body without the aforementioned series of surface treatments and then removed from the body. As can be seen from the diagram, the stent body is contaminated with blood and the entire stent body is deformed, indicating that the stent body has poor antithrombotic performance. Figure 8 This is a schematic diagram of the surface-treated stent body 11 implanted into the body and removed from the body according to an embodiment of this application. As can be seen from the figure, the surface of the stent body 11 is clean and the overall shape of the stent body 11 has not changed, indicating that the stent body 11 provided in this embodiment of the application has good antithrombotic performance.

[0052] In this embodiment of the application, the treatment of the surface of the cylindrical structure with a mixed oxide layer refers to the use of chemical pickling to remove the uncontrollable, thick, and mixed oxide layer on the cylindrical structure; the oxide layer in the mixed oxide layer treatment includes, but is not limited to, chromium trioxide, cobalt oxide, nickel oxide, etc.

[0053] In this embodiment of the application, the specific process of forming a passivation film on the surface of the cylindrical structure includes: placing the polished cylindrical structure in a controlled environment, and using a selective corrosion plus surface self-passivation film reconstruction process to naturally generate an extremely pure passivation film on the surface of the cylindrical structure, which is only a few nanometers thick and is composed entirely of chromium trioxide, thereby improving the biocompatibility and corrosion resistance of the support body 11 made of the cylindrical structure.

[0054] In the embodiments of this application, a phosphoric acid choline antithrombotic coating is formed on the passivation film by a dip-coating process.

[0055] Based on the same inventive concept, embodiments of this application provide a blood flow guidance system, such as... Figures 1 to 5 As shown, the blood flow guiding system includes: a delivery device 2 and a blood flow guiding device 1 of any of the above embodiments; the delivery device 2 is used to deliver the blood flow guiding device 1.

[0056] It should be noted that since the blood flow guiding system of this application embodiment includes the blood flow guiding device 1 of this application embodiment, the blood flow guiding system of this application embodiment also has the above-mentioned beneficial effects of the blood flow guiding device 1 of this application embodiment, which will not be repeated here.

[0057] Alternatively, in one possible implementation of this application, such as Figures 1 to 5 As shown, the conveying device 2 includes: a core wire 21, and a first marking ring 22, a distal end protection member 23, a second marking ring 24, a friction pad 25, a third marking ring 26 and a proximal end protection member 27 arranged sequentially from the distal end to the proximal end of the core wire 21.

[0058] With the stent body 11 of the blood flow guiding device 1 sleeved on the outer periphery of the distal end of the core wire 21, the second marking ring 24, the friction pad 25 and the third marking ring 26 are located inside the stent body 11.

[0059] In this embodiment, the components of the delivery device 2 work together to ensure stable delivery and precise release of the blood flow guiding device 1 within the microcatheter 28. The first marking ring 22, the second marking ring 24, and the third marking ring 26 together constitute a high-precision imaging and positioning system. Under DSA (Digital Subtraction Angiography) imaging, all three components are clearly visualized, providing accurate reference data to assist the surgeon in real-time judgment of the axial position and release status of the stent body 11 within the blood vessel, reducing surgical difficulty. The second marking ring 24, the friction pad 25, and the third marking ring 26 jointly limit the radial movement of the stent body 11, preventing radial deformation or displacement during delivery. The distal protective element 23 and the proximal protective element 27 respectively constrain the distal and proximal ends of the stent body 11, effectively preventing axial displacement or radial collapse during delivery, thereby significantly improving release accuracy and operational safety.

[0060] Alternatively, in one possible implementation of this application, such as Figures 1 to 5As shown, the distal protective member 23 is sleeved on the outer periphery of the distal end of the core wire 21 and is fixedly connected to the core wire 21; when the stent body 11 of the blood flow guiding device 1 is sleeved on the outer periphery of the distal end of the core wire 21, the distal protective member 23 is located between the first marking ring 22 and the stent body 11.

[0061] In this embodiment, with the stent body 11 of the blood flow guiding device 1 sleeved on the outer periphery of the distal end of the core wire 21, the distal end protection member 23 is located between the first marking ring 22 and the distal end of the stent body 11, and is used to provide axial constraint on the distal end of the stent body 11 to prevent it from moving forward or dislodging during delivery due to blood flow impact or the advancement of the delivery device 2, thereby ensuring that the stent body 11 maintains a stable configuration in complex and tortuous vascular paths.

[0062] In this embodiment of the application, the maximum dimension of the first marking ring 22 along the radial direction of the support body 11 is smaller than the radial dimension of the support body 11.

[0063] Alternatively, in one possible implementation of this application, such as Figures 1 to 5 As shown, the distal protective member 23 includes a fixed part and an extended part connected to each other; the fixed part is sleeved on the outer periphery of the distal end of the core wire 21 and is fixedly connected to the core wire 21; the extended part is configured to extend or retract depending on the rotation direction of the core wire 21. In the extended state, the maximum dimension of the extended part along the radial direction of the support body 11 is greater than the radial dimension of the support body 11.

[0064] In this embodiment, the fixing part of the distal protective member 23 is only fixedly connected to the distal end of the core wire 21, and is not directly connected to the stent body 11, thus avoiding deformation of the stent body 11 caused by direct connection. The unfolding part is connected to the outer periphery of the fixing part, forming an umbrella-shaped or petal-shaped structure. During delivery by the blood flow guiding device 1, the unfolding part is radially unfolded by rotating the core wire 21, forming a flexible limit and protection for the distal end of the stent body 11; when the target position is reached and the stent body 11 is released, the core wire 21 is rotated in the opposite direction, causing the unfolding part to retract radially, releasing the limit on the distal end of the stent body 11, facilitating the smooth release of the stent body 11 and its separation from the delivery device 2. The distal protective member 23 of this embodiment can be smoothly opened in vivo without external pre-opening, and the unfolding and retraction process is completely controllable, avoiding the risk of vascular damage caused by insufficient pre-opening or excessive unfolding of traditional distal protective members.

[0065] Alternatively, in one possible implementation of this application, such as Figures 1 to 4 As shown, the friction pad 25 is located between the second marking ring 24 and the third marking ring 26, and the friction pad 25 is movably sleeved on the outer periphery of the core wire 21; the second marking ring 24 and the third marking ring 26 are both sleeved on the outer periphery of the core wire 21 and are fixedly connected to the core wire 21.

[0066] In this embodiment, the inner diameter of the friction pad 25 is increased so that the friction pad 25 can be movably sleeved on the outer periphery of the core wire 21. The second marking ring 24 and the third marking ring 26 are arranged at an axial distance along the core wire 21. The friction pad 25 is disposed between the second marking ring 24 and the third marking ring 26. The support body 11 is sleeved on the outer periphery of the second marking ring 24, the friction pad 25 and the third marking ring 26 to realize the conveying or recycling of the support body 11.

[0067] Alternatively, in one possible implementation of this application, such as Figures 1 to 4 As shown, the blood flow diversion system also includes a microcatheter 28; the delivery device 2 is movably disposed in the microcatheter 28.

[0068] In this embodiment, when the blood flow guiding device 1 needs to be delivered, the microcatheter 28 is punctured into the target blood vessel to establish an external to internal delivery channel. The blood flow guiding device 1 is installed on the delivery device 2 in a preset manner, and the delivery device 2 delivers the blood flow guiding device 1 to the target position along the delivery channel in the microcatheter 28. When the blood flow guiding device 1 needs to be retrieved, the delivery device 2 is operated in reverse so that the stent body 11 is withdrawn from the body along the microcatheter 28.

[0069] Alternatively, in one possible implementation of this application, such as Figures 1 to 4 As shown, the proximal protection member 27 is sleeved on the outer periphery of the distal end of the core wire 21 and is fixedly connected to the core wire 21; when the support body 11 is sleeved on the outer periphery of the distal end of the core wire 21, the proximal protection member 27 is located on the proximal end of the support body 11 on the side close to the proximal end of the core wire 21.

[0070] With the stent body 11 recovered, at least a portion of the proximal protection element 27 is located between the proximal end of the stent body 11 and the inner wall of the microcatheter 28.

[0071] In this embodiment, a proximal protection member 27 is provided between the proximal end of the delivery device 2 and the fourth marking ring 29. During stent body 11 retraction, the proximal protection member 27, located at least a portion near the proximal end of the stent body 11 and between the proximal end of the stent body 11 and the inner wall of the microcatheter 28, eliminates frictional resistance between the proximal end of the stent body 11 and the inner wall of the microcatheter 28. This improves the smoothness and controllability of the stent body 11 during retraction within the microcatheter 28, thereby reducing operational risks during stent body 11 retraction. Furthermore, experiments have shown that adding the proximal protection member 27 reduces the resistance during stent body 11 retraction by at least 60% compared to when the proximal protection member 27 is not added.

[0072] Optionally, in one specific embodiment of this application, 40 nickel-titanium alloy braided wires with a diameter of 0.0012 inches are used to braid the support body 11. The resulting support body 11 has a diameter of 1.75 mm and a length of 8 mm. The porosity of the mesh 112 of the support body 11 is 70%. The mesh 112 of the proximal region 113 and the distal region 115 of the support body 11 is rhomboid in shape. The ends of the excess winding wires 111 (i.e., the unbraided parts) in the distal region 113 and the distal region 115 of the support body 11 are shortened. The mesh density of the distal region 113 and the proximal region 115 is lower than that of the middle region 114. The delivery device 2 includes: a core wire 21, and a first marking ring 22, a distal protection member 23, a second marking ring 24, a friction pad 25 and a third marking ring 26 arranged sequentially from the distal end to the proximal end of the core wire 21. The friction pad 25 is movably sleeved on the core wire 21. A microcatheter 28 with a diameter of 0.017 inches is selected.

[0073] When the above-mentioned blood flow diversion system is used to deliver blood flow diversion device 1 to aneurysms of small vessels with a diameter of 1.75 mm distal to the anterior cerebral artery and distal to the posterior circulation, the distal protective component 23 can be opened relatively easily in the body, and the stent body 11 is tested to have no risk of obstructing branch vessels.

[0074] Optionally, in one specific embodiment of this application, 40 nickel-titanium alloy braided wires with a diameter of 0.0013 inches are used to weave a support body 11. The resulting support body 11 has a diameter of 2 mm and a length of 12 mm. The porosity of the mesh 112 of the support body 11 is 68%. The mesh 112 of the proximal region 113 and the distal region 115 of the support body 11 is rhomboid in shape. The ends of the excess winding wires 111 (i.e., the unwoven parts) in the distal region 113 and the distal region 115 of the support body 11 are shortened, and the mesh density of the distal region 113 and the proximal region 115 is lower than that of the middle region 114. The conveying device 2 includes: a core wire 21, and a first marking ring 22, a distal protection member 23, a second marking ring 24, a friction pad 25, and a third marking ring 26 arranged sequentially from the distal end to the proximal end of the core wire 21. The friction pad 25 is movably sleeved on the core wire 21.

[0075] The blood flow guidance system described above can be used to deliver blood flow guidance device 1 to aneurysms at the bifurcation of the middle cerebral artery (i.e., a ring structure at the bottom of the brain composed of multiple arteries). The delivery process is smooth, and the stent body 11 has high radial force, ensuring that the stent body 11 adheres to the wall at the bifurcation.

[0076] Optionally, in one specific embodiment of this application, 40 nickel-titanium alloy braided wires with a diameter of 0.0015 inches are used to braid the support body 11. The resulting support body 11 has a diameter of 2.5 mm and a length of 15 mm. The porosity of the mesh 112 of the support body 11 is 65%. The mesh 112 of the proximal region 113 and the distal region 115 of the support body 11 is rhomboid in shape. The ends of the excess winding wires 111 (i.e., the unbraided parts) in the distal region 113 and the distal region 115 of the support body 11 are shortened. The mesh density of the distal region 113 and the proximal region 115 is lower than that of the middle region 114. The conveying device 2 includes: a core wire 21, and a first marking ring 22, a distal end protection member 23, a second marking ring 24, a friction pad 25, a third marking ring 26 and a proximal end protection member 27 arranged sequentially from the distal end to the proximal end of the core wire 21. The friction pad 25 is movably sleeved on the core wire 21.

[0077] The blood flow diversion system described above can be used for the delivery and retrieval of blood flow diversion device 1 for aneurysms with a diameter slightly larger than that of the Circle of Willis (i.e., a ring structure at the base of the brain composed of multiple arteries). During delivery, the stent body 11 automatically detaches from the proximal protective member 27, and the deployment of the proximal protective member 27 does not affect the detachment of the stent body 11. During retrieval, the proximal protective member 27 can eliminate the frictional resistance between the proximal end of the stent body 11 and the inner wall of the microcatheter 28, thereby improving the smoothness of retrieval.

[0078] By applying the embodiments of this application, at least the following beneficial effects can be achieved: 1. In this embodiment, multiple braided filaments 111 are interwoven to form a cylindrical support body 11. The mesh density (i.e., the number of mesh openings 112 per unit area) of the distal region 113 and proximal region 115 of the support body 11 is lower than that of the middle region 114 of the support body 11. This results in the radial support force of the distal region 113 and proximal region 115 of the support body 11 being less than that of the middle region 114 of the support body 11, thereby ensuring that the support body 11... While improving the radial support and wall adhesion of the middle region 114, the radial force exerted by the distal region 113 and proximal region 115 of the stent body 11 on the microcatheter 28 is reduced. This reduces the friction between the distal region 113 and the inner wall of the microcatheter 28, as well as between the proximal region 115 and the inner wall of the microcatheter 28. As a result, the smoothness of the stent body 11 in delivery and the control precision within the microcatheter 28 are improved, and the smoothness of the stent body 11 during retrieval is also improved.

[0079] Furthermore, during the delivery of the stent body 11, the distal region 113 of the stent body 11 expands into a trumpet shape. In the distal region 113 of the stent body 11, the ends of the excess braided filaments 111 that do not form mesh 112 are cut short to prevent the ends of the braided filaments 111 that do not form mesh 112 from piercing the inner wall of the microcatheter 28. This reduces the friction between the distal region 113 of the stent body 11 and the inner wall of the microcatheter 28, thereby improving the smoothness of the delivery and the control precision of the stent body 11 within the microcatheter 28.

[0080] Those skilled in the art will understand that the steps, measures, and solutions in the various operations, methods, and processes discussed in this application can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and solutions in the various operations, methods, and processes discussed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and solutions in related technologies that are similar to those disclosed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted.

[0081] In the description of this application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate directions or positional relationships based on the exemplary directions or positional relationships shown in the accompanying drawings. They are used to facilitate the description or simplification of the embodiments of this application and are not intended to indicate or imply that the device or component referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0082] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0083] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0084] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0085] The above description is only a partial implementation of this application. It should be noted that for those skilled in the art, other similar implementation methods based on the technical concept of this application, without departing from the technical concept of this application, also fall within the protection scope of the embodiments of this application.

Claims

1. A blood flow guiding device, characterized in that, include: A support body is formed by interlacing multiple braided filaments; the support body has mesh openings; the support body includes a distal region, a middle region, and a proximal region; the mesh density of the distal region and the proximal region is lower than that of the middle region, and the length of the ends of the braided filaments in the distal region and the proximal region where no mesh openings are formed is smaller than the size of the mesh openings in the distal region and the proximal region.

2. The blood flow guiding device according to claim 1, characterized in that, In the axial plane of the support body, the mesh of the distal region and the proximal region is rhomboid.

3. The blood flow guiding device according to claim 1, characterized in that, It also includes at least one of the following: The number of braiding threads includes at least one of the following: 32, 36, 40, 44, 48, 64, or 72. The diameter of the braided yarns ranges from 0.0006 to 0.003 inches.

4. A blood flow diversion system, characterized in that, include: The delivery device and the blood flow guiding device according to any one of claims 1-3; the delivery device is used to deliver the blood flow guiding device.

5. The blood flow diversion system according to claim 4, characterized in that, The conveying device includes: a core wire, and a first marking ring, a distal end protection member, a second marking ring, a friction pad, a third marking ring, and a proximal end protection member arranged sequentially from the distal end to the proximal end of the core wire; With the stent body of the blood flow guiding device sleeved on the outer periphery of the distal end of the core wire, the second marking ring, the friction pad, and the third marking ring are located inside the stent body.

6. The blood flow diversion system according to claim 5, characterized in that, The distal protective component is sleeved on the outer periphery of the distal end of the core wire and is fixedly connected to the core wire; when the stent body of the blood flow guiding device is sleeved on the outer periphery of the distal end of the core wire, the distal protective component is located between the first marking ring and the stent body.

7. The blood flow diversion system according to claim 6, characterized in that, The distal protective component includes a fixed part and an extended part connected together; the fixed part is sleeved on the outer periphery of the distal end of the core wire and is fixedly connected to the core wire; the extended part is configured to extend or retract depending on the rotation direction of the core wire, and in the extended state, the maximum dimension of the extended part along the radial direction of the support body is greater than the radial dimension of the support body.

8. The blood flow diversion system according to claim 5, characterized in that, The friction pad is located between the second marking ring and the third marking ring, and the friction pad is movably sleeved on the outer periphery of the core wire; the second marking ring and the third marking ring are both sleeved on the outer periphery of the core wire and fixedly connected to the core wire.

9. The blood flow diversion system according to claim 5, characterized in that, It also includes a microcatheter; the delivery device is movably disposed in the microcatheter.

10. The blood flow diversion system according to claim 9, characterized in that, The proximal protective member is sleeved on the outer periphery of the distal end of the core wire and is fixedly connected to the core wire; when the support body is sleeved on the outer periphery of the distal end of the core wire, the proximal protective member is located on the proximal end of the support body on the side close to the proximal end of the core wire. With the stent body recovered, at least a portion of the proximal protection element is located between the proximal end of the stent body and the inner wall of the microcatheter.

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