Guide catheter assembly

Abstract

The utility model relates to the technical field of medical instruments, in particular to a guide catheter assembly which comprises a plurality of layers of sleeve parts, the sleeve parts are thinned step by step from the first step to the Nth step and are sequentially nested, each sleeve part comprises a catheter body, the near end of each catheter body is provided with an operation handle used for controlling the corresponding sleeve part, and the operation handle is connected with the corresponding sleeve part. The far end of the catheter body is in a bent shape relative to the catheter body, and the far end of the catheter body from the first step to the Nth step has the same or different preset curvatures; and the interventional instrument can penetrate through the Nth-step sleeve piece so as to reach the target far-end blood vessel under the guidance of the multi-layer sleeve piece. According to the scheme, the defects that in the prior art, due to the fact that a guiding catheter is not matched with a pulmonary artery anatomical structure, the operation difficulty is large, time is long, and radiation exposure is large are overcome, and an interventional access is rapidly built in interventional therapy with complex and bent blood vessels.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a guide tube assembly. Background Technology

[0002] With the continuous advancement of interventional technology, interventional treatments for pulmonary vascular diseases have been widely applied and developed, including but not limited to pulmonary hypertension, pulmonary thrombectomy, and pulmonary stent thrombectomy. These techniques have become an important part of the clinical treatment of pulmonary vascular diseases. Pulmonary arterial hypertension (PAH) is a disease caused by abnormally high pulmonary artery pressure, which can lead to right heart failure. It can occur as an independent disease or as a complication or syndrome of other diseases. According to hemodynamic diagnostic criteria, pulmonary hypertension can be diagnosed if, at rest at sea level, a right heart catheterization detects a mean pulmonary artery pressure ≥25 mmHg, a pulmonary arteriole wedge pressure ≤15 mmHg, and a pulmonary vascular resistance >3 Wood units. This disease has a high incidence, disability, and mortality rate, thus requiring high attention from the medical field.

[0003] Chronic thromboembolic pulmonary hypertension (CTEPH) is a specific type of pulmonary hypertension caused by fibrotic remodeling of the pulmonary artery intima following a pulmonary embolism. This remodeling is not limited to the original embolic area but also causes varying degrees of remodeling in smaller pulmonary arteries in non-obstructive areas, ultimately leading to increased pulmonary artery pressure and pulmonary vascular resistance, which in turn causes progressive right heart failure, potentially resulting in disability or even death. Despite the large patient population of CTEPH, the number of medical institutions capable of providing accurate diagnosis, assessment, and treatment is extremely limited. In particular, for institutions capable of performing pulmonary endarterectomy (PEA), the number of patients who can undergo this procedure is extremely limited. Therefore, for most CTEPH patients, treatment primarily relies on balloon pulmonary angioplasty (BPA) and medication. However, drug treatments are inconsistent in their effectiveness and are expensive, especially drugs for CTEPH such as Leo Watermelon, whose high price limits patients' treatment options. This makes BPA one of the effective means of treating CTEPH.

[0004] BPA (Bleeding Perfusion) is a minimally invasive interventional technique aimed at improving pulmonary artery blood perfusion, reducing pulmonary artery pressure, and improving right ventricular function by dilating narrowed or occluded pulmonary arteries. Modified BPA techniques focus more on dilating distal arterioles, aiming to restore blood supply to areas with poor blood flow, thereby optimizing blood perfusion distribution, improving the ventilation / perfusion ratio, and increasing arterial oxygen saturation. Due to the characteristics of hemodynamics within the human body, blood flow in the lower lungs is generally higher than in the upper lungs. This means that BPA is more effective in improving hemodynamic levels by restoring blood perfusion in the lower lungs; while restoring blood perfusion in the upper lungs helps improve the ventilation / perfusion ratio, further increasing arterial oxygen saturation. With the improvement in hemodynamics and the increase in arterial oxygen saturation, the heart's pumping efficiency increases, the right ventricular volume decreases, cardiac function is restored, the patient's exercise tolerance increases, symptoms and signs gradually improve, and ultimately the treatment goal is achieved.

[0005] However, the balloon catheter used in BPA procedures needs to be inserted through the femoral vein puncture site and traverse a series of complex paths, including through the inferior vena cava, right atrium, right ventricle, and main pulmonary artery, to finally reach the target lesion. This process involves multiple sharp turns and large bifurcations, especially when the lesion is located in both upper lungs. Precisely guiding the treatment device to the target location becomes one of the key challenges for surgical success. Currently available guiding catheters for pulmonary vascular intervention, such as peripheral multifunctional catheters (e.g., MP catheters) or coronary artery catheters (e.g., JR3.5), are not designed to fully meet the requirements of pulmonary artery anatomy. This not only increases the difficulty and duration of the procedure but also increases radiation exposure for both doctors and patients. Given these circumstances, the development of an interventional guiding catheter specifically designed for the pulmonary artery and similar complex vascular structures is particularly urgent, aiming to significantly improve surgical success rates, reduce surgical time and radiation exposure risks, and ultimately improve patient prognosis and quality of life. Utility Model Content

[0006] This invention provides a guiding catheter assembly to address the shortcomings of existing technologies, such as high surgical difficulty, long operation time, and excessive radiation exposure caused by the mismatch between the guiding catheter and the pulmonary artery anatomy, thereby enabling rapid establishment of interventional access in interventional treatments involving complex and tortuous blood vessels.

[0007] This utility model provides a guiding catheter assembly, comprising: a multi-layered cannula, including multiple cannulas that are progressively thinner and nested from the first to the Nth layer, each cannula including a catheter body, the proximal end of which is provided with an operating handle for manipulating the cannula, and the distal end of which is curved relative to the catheter body, wherein the distal ends of the catheter bodies from the first to the Nth layer have the same or different preset curvatures; and an interventional device capable of passing through the Nth layer of the cannula to reach a target distal blood vessel under the guidance of the multi-layered cannula.

[0008] According to one embodiment of the present invention, among the sleeves from the first to the Nth stage, the inner diameter of the conduit body of any preceding sleeve is greater than the outer diameter of the conduit body of the following sleeve; in the multi-layer sleeves, each sleeve has an independent 360-degree rotational freedom relative to its internal or external adjacent sleeves.

[0009] According to one embodiment of the present invention, in the multi-layer sleeve, the distal end of the conduit body has a preset curvature of 1 to 99 degrees relative to the conduit body.

[0010] According to one embodiment of the present invention, the length of each of the multi-layer sleeves increases progressively from the first to the Nth layer.

[0011] According to one embodiment of the present invention, the end of the catheter body near the operating handle is provided with a scale mark; the total mark length of the scale mark on the catheter body is greater than or equal to the difference in length between the catheter body and the previous catheter body.

[0012] According to one embodiment of the present invention, the distal end of the catheter body is provided with a radiopaque mark; the radiopaque mark includes a ring-shaped mark that surrounds the distal end of the catheter body in a circular pattern, and / or the radiopaque mark includes an elongated mark that extends along the curved shape of the distal end of the catheter body.

[0013] According to one embodiment of the present invention, the catheter body has a multi-layer structure, including an inner layer, an outer layer, and an intermediate layer disposed between the inner layer and the outer layer, wherein the intermediate layer is provided with a mesh anti-torsion structure.

[0014] According to one embodiment of the present invention, the inner layer is a polytetrafluoroethylene coating, and the outer layer is made of polyethylene polymer material.

[0015] According to one embodiment of the present invention, the interventional device includes, but is not limited to, guidewire, balloon catheter, and stent.

[0016] According to one embodiment of the present invention, a locking device is included, the locking device being provided with a locking mechanism for respectively fixing a plurality of operating handles of the multi-layer sleeve fitting.

[0017] The guiding catheter assembly provided by this invention achieves rapid and precise establishment of interventional access in complex and tortuous vascular environments through the use of multi-layered pre-designed curved sheaths. Each layer of the sheath is designed with a pre-defined curvature that conforms to the typical anatomical features of the pulmonary artery and its branches. From the first to the Nth layer, the length of each sheath gradually increases. The distal end of the preceding catheter body provides guidance for the subsequent catheter body, helping it to accurately align with vascular bends or branches. Furthermore, with the aid of the operating handle, the surgeon can precisely control the forward and backward movement of the catheter body and the rotation direction of the distal curved structure, ensuring the catheter can move flexibly in different vascular pathways. This effectively reduces potential damage to the vascular wall during surgery, thereby improving the safety and success rate of the procedure. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of the guide tube assembly provided by this utility model.

[0020] Figure 2 This is an exploded structural diagram of the multi-layer sleeve of the guide tube assembly provided by this utility model.

[0021] Figure 3 This is a structural schematic diagram of the sleeve fitting of the guide tube assembly provided by this utility model.

[0022] Figure 4 This is a schematic diagram of the multi-layer structure of the guide tube body of the guide tube assembly provided by this utility model.

[0023] Figure label:

[0024] 11. Catheter body; 12. Operating handle; 13. Scale markings; 14. Imaging markers; 15. Inner layer; 16. Outer layer; 17. Intermediate layer; 18. Mesh anti-torsion structure; 20. Interventional device. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] In the description of the embodiments of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element 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 the embodiments of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that in the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0027] In existing technologies, the guide catheter is incompatible with the anatomical structure of the pulmonary artery, leading to increased surgical difficulty, longer operation time, and greater radiation exposure. To address these issues, this invention provides a guide catheter assembly. This guide catheter adopts a ladder-like design, featuring extendability and 360-degree rotational guidance, specifically designed for the rapid establishment of interventional access in interventional treatments of complex and tortuous blood vessels such as the pulmonary artery.

[0028] The following is combined with Figures 1 to 4 The following describes the specific implementation of the guide tube assembly of this utility model. It should be understood that the guide tube assembly is a long product in practice, and the accompanying drawings are abbreviated for clarity.

[0029] This invention provides a guiding catheter assembly designed for interventional treatment of the pulmonary artery. The assembly comprises multiple layers of cannulas, which taper progressively from the first to the Nth layer and are nested sequentially. Each cannulas includes a catheter body 11, the proximal end of which is equipped with an operating handle 12 for manipulating the cannulas; the distal end of the catheter body 11 is designed to be curved relative to the catheter body itself, and the distal ends of each catheter body from the first to the Nth layer have the same or different preset curvatures. Furthermore, the interventional device 20 can pass through the innermost layer, the Nth layer, and reach the target distal blood vessel with the assistance of the multi-layer cannulas assembly.

[0030] like Figure 1 and Figure 2 As shown, the guiding catheter assembly of this invention, through its multi-stage preset bending design and the forward / backward and rotation control functions provided by the operating handle 12, achieves the goal of rapidly and accurately establishing an interventional channel in complex and tortuous vascular environments. Each layer of the cannula is endowed with a specific curvature, which is customized according to the typical anatomical structure of the pulmonary artery and its branches to ensure optimal guiding performance. In this invention, from the first to the Nth layer, each cannula in the multi-layer cannula assembly not only decreases in diameter but also increases in length step by step, so that the distal end of the previous layer of the catheter body can effectively guide the next layer, helping it to accurately align with the bends or branches of the blood vessel.

[0031] During use, the doctor will select the appropriate guiding catheter model based on the patient's specific condition and the anatomical features of the pulmonary artery. During the procedure, the doctor will advance the guiding catheter from the femoral vein puncture point along the predetermined path until it reaches the pulmonary artery. Using the handle 12, the doctor can precisely adjust the position and angle of each layer of the catheter body 11, allowing it to smoothly traverse the various bends within the pulmonary artery and ultimately reach the lesion area. With the aid of a multi-level guidance mechanism, the interventional device 20 can reach the target distal vessel under the guidance of the multi-layer cannula assembly, preparing for subsequent treatment procedures such as balloon angioplasty or stent implantation.

[0032] Specifically, the guiding catheter assembly of this invention is preferably designed with a 3 to 5-layer structure, with the diameter of each layer gradually decreasing from the outside to the inside. The outermost layer (first stage) has the largest diameter and is mainly used for initial entry and directional guidance; while the inner layers (second to Nth stages, where N can be equal to 3, 4, or 5) have smaller diameters, enabling more precise turning under the guidance of the previous layer, thereby accurately guiding the interventional instrument 20 to the target distal blood vessel, while minimizing potential damage to the blood vessel wall and improving the safety and success rate of the operation.

[0033] The distal pre-designed curvature of each of the aforementioned cannula fittings can be customized based on the typical anatomical features of the pulmonary artery and its branches. For example, the distal end of the first-order cannula fitting can be designed with a larger curvature to accommodate the tortuosity of the main pulmonary artery; the distal end of the second-order cannula fitting can be designed with a medium curvature to accommodate the major branches of the pulmonary artery; and the distal ends of the third-order and deeper cannula fittings can be designed with a smaller curvature to accommodate smaller, more distal branches. These pre-designed curvatures help provide better guidance and support at vascular bends or branching points.

[0034] Furthermore, the catheter body 11 is preferably made of medical-grade materials with high flexibility and good biocompatibility, such as polyurethane or nylon, to ensure safety and comfort in complex vascular environments. Simultaneously, the catheter surface can be treated with a hydrophilic coating to reduce friction and improve delivery performance.

[0035] According to the present invention, in a guide tube assembly, from the first to the Nth stage of the cannula, the inner diameter of the catheter body 11 of any preceding stage cannula is larger than the outer diameter of the catheter body 11 of the following stage cannula; in the multi-layer cannula assembly, each cannula has an independent 360-degree rotational freedom relative to its internal or external adjacent stage cannula. Through the above-mentioned dimensional design, it is ensured that each layer of cannula can freely rotate and turn under the guidance of the preceding stage cannula, thereby more accurately aligning with the bends or branches of the blood vessel.

[0036] Specifically, in the first to Nth stage of the cannula, the inner diameter of the catheter body 11 of any preceding stage cannula is larger than the outer diameter of the catheter body 11 of the following stage cannula. This ensures that each layer of the cannula can be smoothly nested inside the preceding stage cannula, while leaving sufficient space for the following stage cannula to move and rotate freely. The independent 360-degree rotational freedom of each cannula layer allows the surgeon to precisely adjust the rotation angle of each layer using the operating handle 12, ensuring that the catheter can be accurately aligned with the bends or branches of the blood vessel. This precise guiding capability helps the guiding catheter smoothly navigate complex vascular pathways to reach the target lesion. Because each layer of the cannula can rotate independently, the guiding catheter can more gently adjust its direction when passing through bends or branches of the blood vessel, reducing friction and damage to the vessel wall and improving the safety of the procedure.

[0037] In a preferred embodiment, according to the present invention, in a multi-layered cannula assembly, the distal end of the catheter body 11 has a preset curvature of 1 to 99 degrees relative to the catheter body 11. Specifically, the pulmonary artery and its branches have complex anatomical structures, including multiple bends and bifurcations. The preset curvature of the distal end of the catheter body 11 is designed to be 1 to 99 degrees, which can better adapt to these complex vascular pathways according to actual application scenarios. For example, a smaller preset curvature (such as 1 to 30 degrees) is suitable for gentler bends, while a larger preset curvature (such as 60 to 99 degrees) is suitable for sharper bends or branches. Through the layer-by-layer guidance of the multi-layered cannula, the preset curvature of the distal end of each layer of the cannula can cooperate with each other to achieve precise navigation of complex vascular pathways. The multi-level guidance design allows the guiding catheter to more flexibly cope with various vascular morphologies, improving the accuracy and reliability of guidance.

[0038] Furthermore, preoperative imaging examinations (such as CTA or MRI) allow doctors to gain a detailed understanding of the patient's pulmonary artery anatomy, enabling them to pre-design and manufacture suitable cannulas. Cannulas with different pre-set curvatures can be customized based on each patient's specific condition and the anatomical characteristics of the pulmonary artery. For example, if the lesion is located in a specific branch of the pulmonary artery, doctors can customize a cannulas with a corresponding pre-set curvature based on the distal pre-set curvature of the catheter body 11 of that branch, ensuring the guiding catheter can reach the target location more precisely.

[0039] On the other hand, to meet the needs of different cases, multiple cannulas of the same size but different models can be prefabricated. Each model has the same dimensions but different distal curvatures. For example, cannulas with preset curvatures of 10 degrees, 30 degrees, 60 degrees, and 90 degrees can be prefabricated to cover common vascular bends and branches. In actual surgery, surgeons can quickly select the most suitable cannulas model based on the actual intraoperative situation. This prefabricated, standardized design not only saves surgical preparation time but also improves the flexibility and efficiency of the surgery.

[0040] like Figure 3As shown, according to a guide tube assembly of this utility model, a scale mark 13 is provided at one end of the catheter body 11 near the operating handle 12; the total length of the scale mark 13 on the catheter body 11 is greater than or equal to the difference in length between the catheter body 11 and the previous catheter body 11. Specifically, the scale mark 13 enables the doctor to more precisely control the advancement depth and position of each cannula during operation. Preferably, the total length of the scale mark 13 is greater than or equal to the difference in length between the catheter body 11 and the previous catheter body 11, ensuring that the doctor can clearly determine the relative position of each cannula through the scale mark 13, thereby performing multi-stage guidance more accurately. This precise control not only improves the accuracy and safety of the surgery but also reduces vascular damage and other complications caused by improper operation, improving the success rate of the surgery and the patient's treatment outcome.

[0041] Furthermore, according to a guiding catheter assembly of this utility model, a contrast-enhancing mark 14 is provided at the distal end of the catheter body 11; the contrast-enhancing mark 14 includes an annular mark that surrounds the distal end of the catheter body 11 in a ring shape, and / or the contrast-enhancing mark 14 includes an elongated mark extending along the curved shape of the distal end of the catheter body 11. Specifically, through the contrast-enhancing mark 14, the doctor can clearly observe the position and orientation of the distal end of the catheter during the operation using X-rays or other imaging equipment, thereby performing the operation more precisely. The annular mark helps the doctor determine the overall position of the distal end of the catheter, while the elongated mark can show the direction and degree of curvature of the distal end of the catheter, ensuring that the catheter can be accurately aligned with the bend or branch of the blood vessel. This embodiment not only improves the visualization of the operation, but also enhances the precision and safety of the operation, reduces vascular damage and other complications caused by inaccurate positioning, and improves the success rate of the operation and the treatment effect for the patient.

[0042] like Figure 4 As shown, according to a guide tube assembly of this utility model, the catheter body 11 has a multi-layer structure, including an inner layer 15, an outer layer 16, and an intermediate layer 17 disposed between the inner layer 15 and the outer layer 16. The intermediate layer 17 is provided with a mesh anti-torsion structure 18. The mesh anti-torsion structure 18 can significantly improve the torsional performance and overall stability of the guide tube, ensuring that the catheter will not lose control or be damaged due to torsion in complex vascular environments. Specifically, the mesh anti-torsion structure 18 is evenly distributed in the intermediate layer 17, ensuring that the torsional performance of the catheter is consistent in all directions. Based on the mesh anti-torsion structure 18, the pushing, pulling, and rotational forces applied by the doctor through the operating handle 12 can be effectively transmitted, ensuring that each layer of the cannula can be operated in the expected direction and with the expected force.

[0043] The mesh-like anti-torsion structure 18 can be a woven wire mesh, a polymer fiber mesh, or a composite material mesh. Among these, the woven wire mesh possesses excellent mechanical strength and torsional resistance, effectively preventing the catheter from twisting during advancement and rotation. The polymer fiber mesh offers good biocompatibility and flexibility, providing moderate torsional support. The composite material mesh combines the advantages of both wire and polymer fibers, exhibiting high strength and torsional resistance while also possessing good flexibility and biocompatibility.

[0044] Furthermore, according to the present invention, in a guiding catheter assembly, the inner layer 15 is coated with polytetrafluoroethylene (PTFE), and the outer layer 16 is made of polyethylene polymer material. Specifically, the PTFE coating of the inner layer 15 has an extremely low coefficient of friction, which can significantly reduce the friction inside the guiding catheter, making the catheter body 11 or interventional device 20 (such as guidewire, balloon catheter, or stent delivery system) pass through the guiding catheter more smoothly, reducing advancement resistance, and improving the convenience and efficiency of operation. The polyethylene polymer material of the outer layer 16 has good flexibility, can adapt to complex vascular pathways, reduce damage to the vascular wall, and has good biocompatibility, and will not cause immune response or inflammation in the body.

[0045] According to the present invention, a guiding catheter assembly includes, but is not limited to, any interventional device such as a guidewire, balloon catheter, or stent. Specifically, in conjunction with the guiding catheter assembly, the physician first selects a suitable guiding catheter model based on the patient's specific condition and the anatomical characteristics of the pulmonary artery. Starting from the femoral vein puncture point, the guiding catheter is gradually advanced along a predetermined path to the pulmonary artery. The operating handle 12 is used to finely adjust the advance and retreat positions and rotation angles of each layer of the catheter body 11, allowing the catheter to smoothly pass through the various bends of the pulmonary artery until it approaches the target lesion. Subsequently, the appropriate interventional device 20 is selected as needed: when inserting a guidewire, the guidewire is guided to the target lesion through the innermost sheath 15, ensuring accurate arrival at the target location; when using a balloon catheter, the balloon catheter is inserted through the innermost sheath 15, and after reaching the target location, it is inflated to dilate the narrowed or occluded vessel; when using a stent, the stent delivery system is inserted through the innermost sheath 15, and after reaching the target location, the stent is released to support the narrowed or occluded vessel. Throughout the procedure, doctors can monitor the position of the guiding tube and interventional device 20 in real time using X-rays or other imaging equipment to ensure the accuracy and safety of the operation.

[0046] According to this utility model, a guide tube assembly includes a locking device, which is equipped with a locking mechanism for respectively fixing multiple operating handles 12 of the multi-layered cannula. Specifically, the locking device ensures that each layer of the cannula remains fixed when needed, improving the stability and safety of the surgery. During operation, the surgeon can more precisely control the position and posture of each layer of the cannula through the locking device, preventing errors caused by accidental movement during the operation. The locking device may specifically include multiple clamps arranged in the arrangement direction of the multiple operating handles 12 of the multi-layered cannula. These clamps can firmly fix the operating handles 12 to the worktable when needed, ensuring that each layer of the cannula remains in a predetermined position during the operation, thereby improving the accuracy and safety of the surgery.

[0047] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A guide tube assembly, characterized in that, include: A multi-layered cannula includes multiple cannulas that are progressively thinner and nested from the first to the Nth layer. The cannula includes a catheter body (11), and the proximal end of the catheter body (11) is provided with an operating handle (12) for manipulating the cannula. The distal end of the catheter body (11) is curved relative to the catheter body (11), wherein the distal ends of the catheter bodies (11) from the first to the Nth layer have the same or different preset curvatures. Interventional device (20), which is capable of passing through the Nth layer of the cannula to reach the target distal blood vessel under the guidance of the multi-layer cannula.

2. The guide tube assembly according to claim 1, characterized in that, In the sleeves from the first to the Nth order, the inner diameter of the conduit body (11) of any previous order sleeve is greater than the outer diameter of the conduit body (11) of the subsequent order sleeve. In the multi-layered sleeve assembly, each sleeve assembly has an independent 360-degree rotational freedom relative to its internal or external adjacent sleeve assembly.

3. The guide tube assembly according to claim 1, characterized in that, In the multi-layered tubing, the distal end of the catheter body (11) has a preset curvature of 1 to 99 degrees relative to the catheter body (11).

4. The guide tube assembly according to claim 1, characterized in that, The length of each of the multi-layered sleeves increases progressively from the first to the Nth layer.

5. The guide tube assembly according to claim 4, characterized in that, The catheter body (11) has a scale mark (13) at one end near the operating handle (12); The total length of the scale markings (13) on the catheter body (11) is greater than or equal to the difference in length between the catheter body (11) and the previous catheter body (11).

6. The guide tube assembly according to claim 4, characterized in that, The distal end of the catheter body (11) is provided with a radiopaque marker (14). The imaging mark (14) includes a ring-shaped mark that is circular around the distal end of the catheter body (11), and / or the imaging mark (14) includes an elongated mark that extends in a curved shape along the distal end of the catheter body (11).

7. The guide tube assembly according to any one of claims 1 to 6, characterized in that, The catheter body (11) has a multi-layer structure, including an inner layer (15), an outer layer (16) and an intermediate layer (17) disposed between the inner layer (15) and the outer layer (16), wherein the intermediate layer (17) is provided with a mesh anti-torsion structure (18).

8. The guide tube assembly according to claim 7, characterized in that, The inner layer (15) is a polytetrafluoroethylene coating, and the outer layer (16) is made of polyethylene polymer material.

9. The guide tube assembly according to any one of claims 1 to 6, characterized in that, The interventional device (20) includes, but is not limited to, guidewire, balloon catheter, and stent.

10. The guide tube assembly according to any one of claims 1 to 6, characterized in that, It includes a locking device, which is provided with a locking mechanism for fixing multiple operating handles (12) of the multi-layer sleeve respectively.

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