Microcatheter and preparation method thereof

Abstract

The invention provides a microcatheter and a preparation method thereof, and relates to the technical field of medical instruments. The microcatheter comprises a catheter body, a first developing ring, a second developing ring and a reinforcing tube, the catheter body comprises an inner layer assembly, a middle layer assembly and an outer layer assembly which are sequentially arranged from inside to outside, the middle layer assembly at the far end of the catheter body comprises a spring winding wire, and the first developing ring and the second developing ring are both arranged between the middle layer assembly and the outer layer assembly at the far end of the catheter body; the first developing ring is closer to the far end of the tube body than the second developing ring, and the reinforcing tube is arranged between the middle layer assembly and the second developing ring. The reinforcing tube is arranged between the middle layer assembly and the second developing ring, the far end of the tube body is used for stretching into the human body, and the near end of the tube body is used for being connected with a therapeutic device or conveying a diagnostic preparation to the far end of the tube body. Therefore, the risk that the catheter body is broken at the second developing ring in the use process of the micro catheter is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a microcatheter and a method for preparing the same. Background Art

[0002] Neurointerventional microcatheters are new medical devices used for cardiovascular and cerebrovascular diseases that cannot be treated surgically due to high risk. According to reports, the brain and spinal cord are the nerve centers of the human body, deep or complex lesions such as intracranial aneurysms, carotid sinus fistulas and vascular malformations are often not treatable surgically, or the surgery is difficult and has serious sequelae. In recent years, the continuous development of neurointerventional radiology and the emergence of high-performance polymer catheters have opened up a new era of intravascular treatment of intracranial aneurysms. At present, neurointerventional microcatheters are mainly used in clinical practice to infuse diagnostic agents - such as contrast agents and therapeutic devices - such as coils into neurovascular vessels.

[0003] The microcatheter is mainly composed of a catheter seat, a tube body and a developing ring. The distal end of the tube body is provided with a first developing ring and a second developing ring. The proximal end of the tube body is fixedly connected to the catheter seat. The tube body often breaks at the second developing ring during use. Summary of the invention

[0004] The present application provides a micro-catheter and a method for preparing the same, which can increase the tension at the second developing ring, thereby avoiding or improving the problem of the tube body breaking at the second developing ring.

[0005] In a first aspect, an embodiment of the present application provides a microcatheter, comprising: a tube body, a first developing ring, a second developing ring and a reinforcing tube, the tube body comprising an inner layer component, a middle layer component and an outer layer component arranged in sequence from the inside to the outside, the tube body having a proximal end and a distal end, the middle layer component at the distal end of the tube body comprising a spring wire, the first developing ring and the second developing ring are both arranged between the middle layer component and the outer layer component at the distal end of the tube body, and the first developing ring is closer to the distal end of the tube body than the second developing ring, and the reinforcing tube is arranged between the middle layer component and the second developing ring.

[0006] In the above implementation process, the distal end of the tube body of the microcatheter is used to extend into the human body, and the proximal end of the tube body is used to connect a therapeutic device or deliver a diagnostic agent to the distal end of the tube body. The microcatheter of the present application is capable of increasing the tension at the second developing ring of the microcatheter by providing a reinforcing tube between the intermediate layer assembly and the second developing ring, thereby reducing the risk of the tube body of the microcatheter breaking at the second developing ring during use.

[0007] In a possible implementation manner, the reinforcing tube is connected to the outer layer component, and the second developing ring is embedded between the reinforcing tube and the outer layer component.

[0008] In the above implementation process, the microcatheter of the present application can further increase the tension at the second developing ring of the microcatheter by embedding the second developing ring between the reinforcing tube and the outer layer component, thereby reducing the risk of the microcatheter body breaking at the second developing ring during use.

[0009] In a possible implementation manner, the distances at which both ends of the reinforcing tube extend beyond the corresponding ends of the second developing ring are 0 to 1 cm.

[0010] In the above implementation process, by making the distances at both ends of the reinforcing tube respectively exceed the corresponding ends of the second developing ring within the above range, the pulling force at the second developing ring of the microcatheter can be further increased, thereby reducing the risk of the microcatheter body breaking at the second developing ring during use.

[0011] In a possible embodiment, the material of the reinforcing tube includes at least one of polyamide, nylon and polyurethane.

[0012] In the above implementation process, the microcatheter of the present application selects the above material to make the reinforcement tube, which is beneficial to improving the fusion effect of the reinforcement tube and the outer layer component, and can connect the reinforcement tube and the outer layer component by fusion.

[0013] In a possible implementation manner, the material of the reinforcing tube is the same as that of the outer layer component.

[0014] In the above implementation process, the microcatheter of the present application makes the material of the reinforcing tube and the outer layer component the same, which is beneficial to improving the fusion effect of the reinforcing tube and the outer layer component, and can connect the reinforcing tube and the outer layer component by fusion.

[0015] In a possible embodiment, the material of the inner layer component includes polytetrafluoroethylene.

[0016] In one possible embodiment, the intermediate layer component at the proximal end of the tube body includes braided wires;

[0017] Optionally, the material of the middle layer component includes a metal material;

[0018] Optionally, the metal material includes at least one of stainless steel, nickel titanium and tungsten.

[0019] In a possible embodiment, the hardness of the outer layer component at the distal end of the tube body is smaller than the hardness of the outer layer component at the proximal end of the tube body.

[0020] In a possible embodiment, the tube body further comprises a hydrophilic coating, and the hydrophilic coating is disposed on the outer surface of the outer layer component;

[0021] Optionally, the material of the hydrophilic coating includes polyvinyl pyrrolidone and / or polyacrylamide.

[0022] In the second aspect, an embodiment of the present application provides a method for preparing a microcatheter, including: winding a spring wire around the outer surface of an inner layer component to form an intermediate layer component, then disposing a heat shrink tube outside the intermediate layer component for rheological molding, removing the heat shrink tube, and welding a reinforcing tube to the second developing ring position of the intermediate layer component by hot melting, and then fixing the first developing ring and the second developing ring to the distal end of the outer surface of the intermediate layer component by respectively pressing and gripping, so that the reinforcing tube is arranged between the intermediate layer component and the second developing ring, and then the outer layer component is sleeved on the outside of the inner layer component.

[0023] In the above implementation process, the preparation method of the present application is simple, the prepared micro-catheter structure is stable, and especially the tension at the second developing ring is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic diagram of the structure of a microcatheter according to an embodiment of the present application;

[0026] Figure 2 A perspective view of a tube body according to an embodiment of the present application;

[0027] Figure 3 A schematic diagram of a three-layer structure of a tube body according to an embodiment of the present application;

[0028] Figure 4 for Figure 1 or a radial cross-sectional view at position AA of 2;

[0029] Figure 5 for Figure 1 or 2 radial section view of the BB position.

[0030] Icon: 10-microcatheter; 100-tube body; 101-proximal end; 102-distal end; 110-inner layer component; 111-inner cavity; 120-middle layer component; 121-spring wire; 122-braided wire; 130-outer layer component; 140-hydrophilic coating; 200-catheter seat; 201-main cavity; 300-protective cover; 310-first protective cover; 320-second protective cover; 400-first developing ring; 500-second developing ring; 600-reinforcement tube. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0035] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0036] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] At present, the body of the microcatheter includes an inner layer, a middle layer and an outer layer arranged in sequence from the inside to the outside. The middle layer at the distal end of the body is a coiled spring structure, which can make the distal end of the body have better compliance.

[0038] However, the present applicant has found that the stability of the spring winding structure is poor, which may lead to insufficient tension at the second developing ring of the tube body, which in turn manifests as the tube body breaking at the second developing ring during the use of the microcatheter.

[0039] Based on the above questions, please refer to Figure 1 The present application provides a microcatheter 10 , which includes: a tube body 100 , a catheter seat 200 , a protective sleeve 300 , a first developing ring 400 , a second developing ring 500 and a reinforcing tube 600 .

[0040] The tube body 100 is connected to the catheter seat 200 via a protective sleeve 300 , and the protective sleeve 300 is used to ensure a stable connection between the catheter seat 200 and the tube body 100 .

[0041] Optionally, one end of the protective sleeve 300 is sleeved on the tube body 100 , and the other end of the protective sleeve 300 is connected to the catheter seat 200 by snapping.

[0042] Optionally, the protective cover 300 includes a first protective cover 310 and a second protective cover 320 , one end of the first protective cover 310 is connected to one end of the second protective cover 320 , the other end of the first protective cover 310 is connected to the end of the tube body 100 , and the other end of the second protective cover 320 is connected to the catheter seat 200 .

[0043] Optionally, catheter adapter 200 has a main lumen 201 that can be used to accommodate microguidewires, injected drugs, and therapeutic devices such as coils.

[0044] Optionally, the material of the catheter hub 200 includes nylon and / or polycarbonate.

[0045] See also Figures 1 to 4 The tube body 100 has a proximal end 101 close to the catheter seat 200 and a distal end 102 away from the catheter seat 200. The tube body 100 includes an inner layer component 110, a middle layer component 120 and an outer layer component 130 arranged in sequence from the inside to the outside. The inner layer component 110, the middle layer component 120 and the outer layer component 130 can be fused and formed by rheoforming.

[0046] See also Figures 2 to 5 The inner layer component 110 is a tubular structure, and the inner layer component 110 has an inner cavity 111, and the inner cavity 111 is connected to the main cavity 201 of the catheter seat 200. The inner cavity 111 of the inner layer component 110 is formed as a delivery channel for delivering injection drugs or instruments.

[0047] Optionally, the material of the inner layer component 110 includes polytetrafluoroethylene.

[0048] The middle layer component 120 includes a spring wire 121 and a braided wire 122 , which are fixed on the outer surface of the inner layer component 110 .

[0049] The middle layer component 120 close to the proximal end 101 of the tube body 100 includes a braided wire 122 , and the middle layer component 120 close to the distal end 102 of the tube body 100 includes a spring wire 121 .

[0050] Among them, the braided wire 122 is formed by braiding metal wires, and the spring wire 121 is formed by winding metal wires. The connection between the braided wire 122 and the spring wire 121 is a transition section, and in the transition section, the braided wire 122 and the spring wire 121 overlap, and the intermediate layer component 120 includes the overlapping braided wire 122 and the spring wire 121.

[0051] Optionally, the material of the spring wire 121 and the braided wire 122 includes metal material.

[0052] Optionally, the material of the spring wire 121 and the braided wire 122 includes at least one of stainless steel, nickel titanium and metal tungsten.

[0053] It should be noted that the materials of the spring wire 121 and the braided wire 122 can be the same or different. For example, the materials of the spring wire 121 and the braided wire 122 are both stainless steel, nickel-titanium alloy or metal tungsten; or the spring wire 121 is stainless steel and the braided wire 122 is nickel-titanium alloy; or the spring wire 121 is metal tungsten and the braided wire 122 is nickel-titanium alloy; or the spring wire 121 is nickel-titanium alloy and the braided wire 122 is stainless steel.

[0054] The outer layer component 130 is a tubular structure, which is sleeved on the inner layer component 110, and the outer layer component 130 and the inner layer component 110 are coaxially connected. The inner surface of the outer layer component 130 abuts against the middle layer component 120, and a spiral channel for conveying contrast agent is formed between the inner layer component 110 and the outer layer component 130.

[0055] The hardness of the outer layer component 130 at the distal end 102 of the tube body 100 is smaller than the hardness of the outer layer component 130 at the proximal end 101 of the tube body 100 .

[0056] Optionally, the outer layer component 130 of the tube body 100 includes a first section, a second section, a third section and a fourth section extending sequentially from the proximal end 101 to the distal end 102, and the hardness of the first section is greater than the hardness of the second section, which is greater than the hardness of the third section, which is greater than the hardness of the fourth section. The first section, the second section, the third section and the fourth section of the outer layer component 130 of the tube body 100 can be welded by hot melting, laser welding or a combination thereof to form the entire outer layer component 130.

[0057] Optionally, the hardness of the first section of the outer layer component 130 of the tube body 100 is 72D, the hardness of the second section is 55D, the hardness of the third section is 40D, and the hardness of the fourth section is 35D.

[0058] The material of the outer layer component 130 includes at least one of polyamide, nylon and polyurethane.

[0059] The outer surface of the outer layer component 130 is provided with a hydrophilic coating 140 , and the hydrophilic coating 140 can be formed on the outer surface of the outer layer component 130 by photocuring, thermal curing, etc.

[0060] Optionally, the material of the hydrophilic coating 140 includes polyvinyl pyrrolidone and / or polyacrylamide.

[0061] The first developing ring 400 and the second developing ring 500 are both arranged between the middle layer component 120 and the outer layer component 130 of the distal end 102 of the tube body 100, and the first developing ring 400 is closer to the distal end 102 of the tube body 100 than the second developing ring 500, and the reinforcing tube 600 is arranged between the middle layer component 120 and the second developing ring 500.

[0062] Optionally, the first developing ring 400 and the second developing ring 500 are both made of platinum-iridium alloy.

[0063] Optionally, the hardness of the outer layer component 130 against which the second developing ring 500 abuts is 35D.

[0064] The reinforcing tube 600 can be welded between the middle layer component 120 and the second developing ring 500 by hot melt. During this welding process, the reinforcing tube 600 is fused with the outer layer component 130 by rheology, which can not only connect the tube bodies 100 to each other and play a circulation role during rheology, but also enable the second developing ring 500 to be embedded between the reinforcing tube 600 and the outer layer component 130, which can further increase the tension at the second developing ring 500 of the microcatheter 10, thereby reducing the risk of the tube body 100 breaking at the second developing ring 500 during use of the microcatheter 10.

[0065] Optionally, both ends of the reinforcing tube 600 are respectively aligned with or extend beyond the corresponding ends of the second developing ring 500 .

[0066] The corresponding relationship between the two ends of the reinforcing tube 600 and the corresponding ends of the second developing ring 500 is as follows:

[0067] The end of the reinforcing tube 600 away from the proximal end 101 of the tube body 100 (i.e., close to the distal end 102 of the tube body 100) corresponds to the end of the second developing ring 500 away from the proximal end 101 of the tube body 100 (i.e., close to the distal end 102 of the tube body 100), and the end of the reinforcing tube 600 close to the proximal end 101 of the tube body 100 (i.e., away from the distal end 102 of the tube body 100) corresponds to the end of the second developing ring 500 close to the proximal end 101 of the tube body 100 (i.e., away from the distal end 102 of the tube body 100).

[0068] Optionally, the distances at which both ends of the reinforcing tube 600 exceed the corresponding ends of the second developing ring 500 are 0 to 1 cm.

[0069] As an example, the distances by which both ends of the reinforcing tube 600 extend beyond the corresponding ends of the second developing ring 500 may be 0, 0.1 cm, 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm or 1 cm.

[0070] It should be noted that when the distance between the two ends of the reinforcing tube 600 and the corresponding ends of the second developing ring 500 is 0, the two ends of the reinforcing tube 600 are respectively aligned with the corresponding ends of the second developing ring 500.

[0071] By making the distances at both ends of the reinforcing tube 600 respectively beyond the corresponding ends of the second developing ring 500 within the above range, the tension at the second developing ring 500 of the microcatheter 10 can be further increased, thereby reducing the risk of the tube body 100 of the microcatheter 10 breaking at the second developing ring 500 during use.

[0072] Optionally, the material of the reinforcing tube 600 includes at least one of polyamide, nylon and polyurethane.

[0073] The microcatheter 10 of the present application selects the above-mentioned material to make the reinforcing tube 600, which is beneficial to improving the fusion effect of the reinforcing tube 600 and the outer layer component 130, and can connect the reinforcing tube 600 and the outer layer component 130 by fusion.

[0074] Optionally, the material of the reinforcing tube 600 is the same as the material of the outer layer component 130 .

[0075] For example, when the material of the outer layer component 130 is polyamide, the material of the reinforcing tube 600 is also polyamide; when the material of the outer layer component 130 is nylon, the material of the reinforcing tube 600 is also nylon; when the material of the outer layer component 130 is polyurethane, the material of the reinforcing tube 600 is also polyurethane; when the material of the outer layer component 130 is a mixture of polyurethane and nylon, the material of the reinforcing tube 600 is also a mixture of polyurethane and nylon; when the material of the outer layer component 130 is a mixture of polyamide and nylon, the material of the reinforcing tube 600 is also a mixture of polyamide and nylon.

[0076] The microcatheter 10 of the present application makes the material of the reinforcing tube 600 and the material of the outer layer component 130 the same, which is beneficial to improving the fusion effect of the reinforcing tube 600 and the outer layer component 130, and can connect the reinforcing tube 600 and the outer layer component 130 by fusion.

[0077] The present application also provides a method for preparing a microcatheter, which comprises the following steps:

[0078] S1, forming inner layer component 110

[0079] The inner layer component 110 is formed into a tubular shape using polytetrafluoroethylene as a raw material.

[0080] S2. Forming an intermediate layer component 120

[0081] The inner layer component 110 is straightened, and the metal wire is firstly mesh-woven on the outer surface of the proximal end 101 of the inner layer component 110 to form a braided wire 122, and spot welding is performed during the braiding process so that the braided wire 122 is stably and tightly attached to the outer surface of the inner layer component 110. After the braiding of the braided wire 122 is completed, the metal wire is spirally wound on the outer surface of the inner layer component 110 at a position where the braided wire 122 is close to the distal end 102 of the inner layer component 110 to form a spring wire 121, until it is wound to the distal end 102 of the inner layer component 110, and the braided wire 122 and the spring wire 121 overlap in the transition section between the spring wire 121 and the braided wire 122. After the winding is completed, a heat shrink tube is arranged outside the middle layer component 120 for flow molding, so that part of the braided wire 122 and / or the spring wire 121 are embedded in the inner layer component 110.

[0082] S3, fixing the first developing ring 400 and the second developing ring 500

[0083] Remove the heat shrink tube, determine the position of the first developing ring 400 and the second developing ring 500, first weld the reinforcing tube 600 to the position of the second developing ring 500 of the middle layer component 120 by hot melting, and then fix the first developing ring 400 and the second developing ring 500 to the distal end 102 of the outer surface of the middle layer component 120 by pressing and gripping, and the first developing ring 400 is closer to the distal end 102 of the outer layer component 130 than the second developing ring 500, and the two ends of the reinforcing tube 600 exceed the corresponding ends of the second developing ring 500 by 0 to 1 cm.

[0084] S4. Preparation of tube body 100

[0085] The outer layer component 130 is sleeved on the inner layer component 110, and the tube body 100 is placed in a heat shrink tube and subjected to rheological melting in a rheometer. During this process, the reinforcing tube 600 is fused with the outer layer component 130 by rheology, which not only connects the tube bodies 100 to each other and plays a circulation role during rheology, but also enables the second developing ring 500 to be embedded between the reinforcing tube 600 and the outer layer component 130 to obtain the tube body 100.

[0086] S5, forming a hydrophilic coating 140

[0087] The hydrophilic coating 140 slurry is coated on the outer surface of the outer layer component 130 , and then the hydrophilic coating 140 is formed on the outer surface of the outer layer component 130 by photocuring, thermal curing or the like.

[0088] S6. Assembly

[0089] The catheter seat 200 , the protective cover 300 and the prepared tube body 100 are sequentially connected and assembled to form a micro-catheter 10 .

[0090] The present application provides a microcatheter 10, which includes a tube body 100, a catheter seat 200, a protective sleeve 300, a first developing ring 400, a second developing ring 500 and a reinforcing tube 600; the protective sleeve 300 includes a first protective sleeve 310 and a second protective sleeve 320, one end of the first protective sleeve 310 is connected to one end of the second protective sleeve 320, the other end of the first protective sleeve 310 is connected to the end of the tube body 100, and the other end of the second protective sleeve 320 is connected to the catheter seat 200; the catheter seat 200 has a main cavity 201, and the main cavity 201 can be used for compatibility with micro guide wires, injection drugs and therapeutic devices-such as spring coils, and the material of the catheter seat 200 is polycarbonate; the tube body 100 has a proximal portion close to the catheter. The proximal end 101 of the seat 200 and the distal end 102 away from the catheter seat 200, the tube body 100 includes an inner layer component 110, an intermediate layer component 120 and an outer layer component 130 arranged in sequence from the inside to the outside, the inner layer component 110 is a tubular structure, the inner layer component 110 has an inner cavity 111, the inner cavity 111 is connected to the main cavity 201 of the catheter seat 200, the inner cavity 111 of the inner layer component 110 is formed as a delivery channel for delivering injection drugs or instruments, the material of the inner layer component 110 is polytetrafluoroethylene, the intermediate layer component 120 includes a braided wire 122 located at the proximal end 101 and a spring wire 121 located at the distal end 102, the connection between the braided wire 122 and the spring wire 121 is a transition section, in the transition section, the braided wire The outer layer component 130 is a tubular structure, and the outer layer component 130 is sleeved outside the inner layer component 110, and the outer layer component 130 and the inner layer component 110 are coaxially connected. The inner surface of the outer layer component 130 abuts against the middle layer component 120, and a spiral channel for conveying contrast agent is formed between the inner layer component 110 and the outer layer component 130. The outer layer component 130 of the tube body 100 includes a first section, a second section, a third section and a fourth section extending from the proximal end 101 to the distal end 102 in sequence. The hardness of the first section is 72D, the hardness of the second section is 55D, the hardness of the third section is 40D, and the hardness of the fourth section is 35D. The component 130 is made of nylon, and the outer surface of the outer layer component 130 is also provided with a hydrophilic coating 140 including polyvinyl pyrrolidone; the first developing ring 400 and the second developing ring 500 are both arranged between the middle layer component 120 and the outer layer component 130 at the distal end 102 of the tube body 100, and the first developing ring 400 is closer to the distal end 102 of the tube body 100 than the second developing ring 500, and the reinforcing tube 600 is arranged between the middle layer component 120 and the second developing ring 500, and the material of the first developing ring 400 and the second developing ring 500 are both platinum-iridium alloy, and the two ends of the reinforcing tube 600 respectively exceed the corresponding ends of the second developing ring 500 by 0.5 cm, and the material of the reinforcing tube 600 is nylon.

[0091] In summary, the distal end 102 of the tube body 100 of the microcatheter 10 is used to extend into the human body, and the proximal end 101 of the tube body 100 is used to connect a therapeutic device or deliver a diagnostic agent to the distal end 102 of the tube body 100. The microcatheter 10 of the present application is capable of increasing the tension at the second developing ring 500 of the microcatheter 10 by providing a reinforcing tube 600 between the intermediate layer component 120 and the second developing ring 500, thereby reducing the risk of the tube body 100 breaking at the second developing ring 500 during use of the microcatheter 10.

[0092] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A microcatheter, characterized in that: The microcatheter includes: a tube body, a first developing ring, a second developing ring and a reinforcing tube, the tube body includes an inner layer component, a middle layer component and an outer layer component arranged in sequence from the inside to the outside, the tube body has a proximal end and a distal end, the middle layer component at the distal end of the tube body includes a spring wire, the first developing ring and the second developing ring are both arranged between the middle layer component and the outer layer component at the distal end of the tube body, and the first developing ring is closer to the distal end of the tube body than the second developing ring, and the reinforcing tube is arranged between the middle layer component and the second developing ring.

2. The microcatheter according to claim 1, characterized in that: The reinforcing tube is connected to the outer layer component, and the second developing ring is embedded between the reinforcing tube and the outer layer component.

3. The microcatheter according to claim 1, characterized in that: The distances at which both ends of the reinforcing tube exceed the ends corresponding to the second developing ring are 0 to 1 cm.

4. The microcatheter according to claim 1, characterized in that: The material of the reinforcement tube includes at least one of polyamide, nylon and polyurethane.

5. The microcatheter according to claim 1, characterized in that: The material of the reinforcement tube is the same as that of the outer layer component.

6. The microcatheter according to any one of claims 1 to 5, characterized in that: The material of the inner layer component includes polytetrafluoroethylene.

7. The microcatheter according to any one of claims 1 to 5, characterized in that: The intermediate layer component of the proximal end of the tube body includes a braided wire; Optionally, the material of the intermediate layer component includes metal material; Optionally, the metal material includes at least one of stainless steel, nickel titanium and tungsten.

8. The microcatheter according to any one of claims 1 to 5, characterized in that: The hardness of the outer layer component at the distal end of the tube body is smaller than the hardness of the outer layer component at the proximal end of the tube body.

9. The microcatheter according to any one of claims 1 to 5, characterized in that: The tube body further comprises a hydrophilic coating, and the hydrophilic coating is disposed on the outer surface of the outer layer component; Optionally, the material of the hydrophilic coating includes polyvinyl pyrrolidone and / or polyacrylamide.

10. A method for preparing a microcatheter according to any one of claims 1 to 9, characterized in that: The preparation method of the microcatheter includes: winding the spring wire around the outer surface of the inner layer component to form the middle layer component, then arranging a heat shrink tube outside the middle layer component for rheological molding, removing the heat shrink tube, welding the reinforcing tube to the second developing ring position of the middle layer component by hot melting, and then fixing the first developing ring and the second developing ring to the distal end of the outer surface of the middle layer component by pressing and gripping, so that the reinforcing tube is arranged between the middle layer component and the second developing ring, and then the outer layer component is sleeved outside the inner layer component.

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