Etching pipe and preparation method and application thereof

Abstract

The invention provides an etching tube and a preparation method and application thereof, and belongs to the technical field of medical instruments. The etching tube comprises an etching tube body, a plurality of rows of through holes are formed in the etching tube body from the leading-in end to the leading-out end in the axial direction of the etching tube body, and each row is provided with a plurality of through holes used for improving flexibility and compliance. According to the preparation method, the metal core rod matched with the size of the inner wall of the etching pipe body is inserted into the etching pipe body, the metal core rod is tightly attached to the inner wall of the etching pipe body, and then the outer wall of the etching pipe body is perforated. When the etching tube is used in a micro-catheter, the problem of poor passing ability caused by a traditional continuous tubular etching tube can be solved; meanwhile, the stress effect on the blood vessel wall in the pushing process is reduced, the blood vessel penetration and interlayer risks and the occurrence rate of vasospasm are reduced, the hemodynamic stability in the operation is improved, the smooth performance is finely controlled, the pushing performance and the size stability are both considered, and the controllability and safety of the operation are improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to etched tubes, their preparation methods, and applications. Background Technology

[0002] Cerebral aneurysms and arteriovenous malformations (AVMs) are two common intracranial vascular abnormalities with high risks of disability and death. Cerebral aneurysms usually result from congenital weakness of the vessel wall, long-term hypertension, or arteriosclerosis, leading to local vascular dilation and the formation of aneurysmal protrusions. Rupture can cause subarachnoid hemorrhage, which can lead to sudden death in severe cases. Cerebral arteriovenous malformations, on the other hand, are congenital vascular developmental abnormalities characterized by the lack of a normal capillary network between arteries and veins, forming abnormal blood flow channels that can easily induce clinical symptoms such as epilepsy, headache, or cerebral hemorrhage.

[0003] With the development of interventional neurosurgery techniques, the mainstream treatment for the aforementioned lesions is currently minimally invasive embolization via a transvascular approach. This procedure requires establishing an access through the femoral or radial artery, guiding the patient to the lesion area with a guidewire and microcatheter system, and then releasing coils, liquid embolic agents, or flow diversion devices through the microcatheter to seal the aneurysm or malformed lesion.

[0004] In this process, the microcatheter system serves as a crucial carrier for instrument delivery and positioning. Its flexibility, throughput, delivery performance, and directional controllability directly impact the success rate and safety of the surgery. An ideal microcatheter must possess excellent flexibility to adapt to the tortuous intracranial vascular pathways, while maintaining sufficient support to carry various therapeutic instruments.

[0005] Most commercially available microcatheters currently employ a composite structure design to balance flexibility, force transmission, and channel stability. Our product's microcatheter consists of a three-layer structure: an inner PTFE etched tube, which reduces the internal friction coefficient to enhance device delivery smoothness and provides basic structural support; a middle braided metal layer, typically made of stainless steel or nickel-titanium alloy wire mesh, designed to improve the catheter's pressure resistance and overall delivery force; and an outer polymer elastomer sheath, providing morphological protection and a biocompatible contact interface. While the PTFE etched tube possesses excellent chemical inertness and a low coefficient of friction, its continuous tubular structure can easily create a rigid transition zone within the microcatheter, resulting in greater overall rigidity and potentially causing the following clinical problems: 1. Catheters have difficulty passing through tortuous intracranial blood vessels, especially when entering branches of the middle cerebral artery and the vertebrobasilar artery system, where their permeability is significantly reduced; 2. The pushing process applies significant stress to the blood vessel wall, increasing the risk of blood vessel perforation or dissection; 3. Insufficient flexibility can easily induce vasospasm, affecting intraoperative hemodynamic stability and surgical controllability; 4. Insufficient catheter stability may cause the release position to deviate when releasing the spring coil or embolization material.

[0006] Therefore, how to effectively improve the flexibility of microcatheters while maintaining catheter delivery performance and dimensional stability has become a key technical challenge that urgently needs to be overcome in the field of microcatheter design. Summary of the Invention

[0007] In view of this, in order to improve the flexibility of microcatheters, the present invention provides an etched tube, its preparation method and application. By opening multiple rows of through holes on the etched tube, the axial stiffness of the tube body is significantly reduced while maintaining the unobstructed inner lumen and structural integrity of the catheter, thereby effectively improving the overall flexibility and conformability of the microcatheter.

[0008] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides an etched tube, comprising: The etched tube body has multiple rows of through holes along its axial direction from the inlet end to the outlet end, with each row having multiple through holes to improve flexibility and conformability.

[0009] Preferably, at least four rows of through holes are provided.

[0010] Preferably, four rows of through holes are provided.

[0011] Preferably, each row of through holes is straight, spiral, or staggered.

[0012] Preferably, the material of the etched tube body is polytetrafluoroethylene.

[0013] Secondly, the present invention provides a method for preparing the above-mentioned etched tube, comprising the following steps: Step (1): Insert a metal core rod that matches the inner wall size into the etched tube body and fit it tightly against the inner wall of the etched tube body. Step (2): Make holes in the outer wall of the etched tube body.

[0014] Preferably, in step (2), a laser cutting device is used to make the hole.

[0015] Thirdly, the present invention provides a microcatheter, comprising an outermost sheath, a middle metal braided layer, and an outermost etched tube, wherein the etched tube is the etched tube according to any one of claims 1-5.

[0016] Fourthly, the present invention also provides the application of the above-mentioned etched tube in microcatheters.

[0017] The etched tube, its preparation method, and its application provided by this invention significantly reduce the axial stiffness of the tube body by creating multiple rows of through holes in the etched tube, while maintaining the unobstructed inner lumen and structural integrity of the catheter, thereby effectively improving the overall flexibility and conformability of the microcatheter. Compared with the prior art, it has the following beneficial effects: The etched tube provided by this invention can be specifically applied to the optimization of microcatheter structures in neurointerventional or vascular interventional therapies. As the innermost structure of the microcatheter, its core is to form a thiocyanate tube structure by creating multiple rows and multiple through holes on the outer wall of a hollow etched tube made of polytetrafluoroethylene (PTFE), thereby improving the flexibility and adaptability of the microcatheter. During the processing of this etched tube, a metal mandrel of matching size is inserted into the tube to provide structural support and thermal stability. Then, a high-precision laser cutting device is used to pattern and open holes on the outer wall of the tube, forming a flexible area with at least four rows of through holes. This allows for flexible adjustment of the microcatheter in multiple directions, while ensuring a smooth and unobstructed inner lumen, maintaining the low coefficient of friction of the PTFE material, and ensuring the smoothness of instrument delivery and structural support.

[0018] The etched tube provided by this invention primarily addresses the technical problem of rigid transition zones easily formed in the continuous tubular structure of existing microcatheters. Specifically, this manifests as difficulties in passing through tortuous intracranial vessels (such as branches of the midbrain artery and the vertebrobasilar artery system), high stress on the vessel wall during advancement leading to perforation or dissection risks, insufficient flexibility inducing vasospasm, and insufficient stability during device release causing deviations. By using patterned perforations on the outer wall of the etched tube, the axial stiffness of the tube can be significantly reduced, improving the overall flexibility and adaptability of the microcatheter. This allows it to travel more closely along vessel walls in complex vascular pathways, reducing stimulation and operational risks. Simultaneously, the length and density of the perforations can be adjusted according to different interventional pathways and surgical procedures, achieving precise control of flexibility while balancing advancement and dimensional stability.

[0019] Compared to traditional methods that alter flexibility by adjusting material hardness or overall wall thickness, the etched tube provided by this invention has significant advantages: Laser cutting offers high precision, and when combined with a metal mandrel support, it can prevent tube deformation, collapse, or thermal damage, resulting in strong product consistency and repeatability. The structured flexible adjustment method offers greater design freedom, balancing flexibility and support while maintaining the patency of the internal cavity and structural integrity, providing a safer and more controllable instrument delivery channel for neurointerventional surgery. Attached Figure Description

[0020] Figure 1 A schematic diagram of the overall structure of the linear etching tube provided by the present invention; Figure 2 This is a schematic diagram of the overall structure of the spiral etching tube provided by the present invention; Figure 3 This is a schematic diagram of the overall structure of the staggered etching tube provided by the present invention; In the diagram, 1 is the etched tube body; 2 is the through hole. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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 this invention.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" 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 an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] like Figure 1-3 As shown, the present invention provides an etched tube, comprising: The etched tube body 1 has multiple rows of through holes 2 along its axial direction from the inlet end to the outlet end, with each row having multiple through holes 2 to improve flexibility and conformability. Preferably, the etched tube body 1 has at least four rows of through holes 2. More preferably, it has four rows of through holes 2. Further, as... Figure 1-3As shown, each row of through holes 2 is preferably linear, spiral, or staggered. In this invention, the material of the etched tube body 1 is preferably polytetrafluoroethylene (PTFE). The etched tube body 1 is a hollow PTFE tube, serving as the innermost structure of the microcatheter. By opening multiple rows of through holes 2 on its outer wall, a flexible region of the thiocyanate tube structure is formed, breaking the rigid transition zone of the traditional continuous tubular structure, significantly reducing the axial stiffness of the tube body, thereby effectively improving the overall flexibility and compliance of the microcatheter. This makes it easier for the microcatheter to travel along the wall in curved blood vessels (such as branches of the cerebral arteries and the vertebrobasilar artery system), solving the technical problem of "poor passability" and improving the accessibility of distal blood vessels. It reduces the stress on the blood vessel wall during the pushing process, reducing the risk of blood vessel wall penetration or dissection, while also reducing the incidence of vasospasm and improving the dynamic stability of blood flow during the operation.

[0025] In this invention, the length, density, and layout of the through holes 2 can be adjusted according to the requirements of the intervention path. The through holes 2 provided above are in the form of straight lines, spirals, or staggered lines. These are merely preferred embodiments given by way of example. Those skilled in the art can also choose other layout forms according to actual needs, and there are no special requirements for this.

[0026] In this invention, flexible regions are customized for different surgical procedures (such as coil release and liquid embolization delivery) to improve the controllability of surgical operations. For example, the density of through-holes 2 is increased in vascular segments with sharp turns to enhance local compliance, while the number of through-holes 2 is reduced in areas requiring support to ensure delivery performance, which can be selected according to actual needs.

[0027] Secondly, the present invention provides a method for preparing the above-mentioned etched tube, comprising the following steps: First, a metal core rod matching the inner wall size is inserted into the etching tube body 1 and tightly fitted to the inner wall of the etching tube body 1. Then, an opening is made in the outer wall of the etching tube body 1. Specifically: First, a metal core rod of the same size as the inner wall is inserted into an etched tube made of polytetrafluoroethylene (PTFE) to provide structural support and thermal stability. The metal core rod fits tightly against the inner wall of the etched tube body 1. Then, a high-precision laser cutting device is used to pattern and create openings on the outer wall of the etched tube, forming a flexible area structure of the thiocyanate tube. The metal core rod helps ensure the smooth delivery of medical devices (such as guidewires and coils), avoiding device jamming or release deviations caused by roughness in the inner lumen. The etched tube body 1 maintains its structural integrity after the opening, avoiding the risk of channel collapse due to increased flexibility and ensuring catheter stability during the release of embolic material. Laser cutting only acts on the outer wall, ensuring a smooth and unobstructed inner lumen. Laser cutting can precisely control the structural parameters of the through-hole 2, such as length and width. Compared with the traditional method of "adjusting material hardness or wall thickness", the processing accuracy is higher, the repeatability is stronger, the product flexibility difference is smaller in mass production, and the stability in clinical use is better.

[0028] In summary, the preparation method provided by this invention can effectively control the shape and layout of the through-hole 2, avoiding deformation, collapse, or thermal damage to the etched tube body 1 during processing. This results in an etched tube with good flexibility, structural integrity, and a smooth inner lumen, providing a reliable means for the overall flexibility design of microcatheters. Through the synergy of "flexible region of the thiopancreatography tube structure + high-precision processing technology," the problem of "rigid transition" in existing microcatheters is solved, while achieving a balance between "flexibility, support force, and delivery performance." This significantly improves the safety and controllability of neurointerventional surgery and provides a structured solution for personalized vascular treatment plans.

[0029] This invention provides a microcatheter, comprising an outermost sheath, a middle metal braided layer, and an outermost etched tube, wherein the etched tube is the aforementioned etched tube. In this microcatheter, the sheath, as the outermost layer, is made of a high-molecular-weight elastomer material and directly contacts the blood vessel wall, its main functions including: Provides shape protection to prevent damage to the middle metal braided layer and the inner etched tube from external friction or compression; It imparts good biocompatibility to microcatheters, reduces irritation to vascular endothelium, and lowers the risk of thrombosis; Maintain the integrity of the overall morphology of the catheter to ensure stable connection of each layer of structure during delivery and operation.

[0030] The intermediate braided metal layer is preferably made of stainless steel or nickel-titanium alloy wire mesh. Its main function is to improve the microcatheter's pressure resistance and overall pushing force. The braided metal structure further enhances the catheter's structural stability when bent or under pressure, preventing catheter collapse. At the same time, it effectively transmits the operator's pushing force to the distal end, ensuring the microcatheter's maneuverability and passage through complex vascular pathways, and balancing the potential decrease in support force that might result from the increased flexibility of the inner etched tube.

[0031] The innermost etched tube, as the innermost structure of the microcatheter, is made of polytetrafluoroethylene (PTFE) and has multiple rows of through holes 2 along the axial direction from the inlet to the outlet. Its core function is to form a flexible region of the thiocyanate tube structure through the patterned openings on the outer wall, breaking the rigid transition zone of the traditional continuous tubular structure, significantly reducing the axial stiffness of the tube, and thus improving the overall flexibility and adaptability of the microcatheter.

[0032] Fourthly, the present invention also provides the application of the above-mentioned etched tube in microcatheters. The etched tube used in microcatheters can solve the problem of "poor permeability" caused by traditional continuous tubular etched tubes; at the same time, it reduces the stress on the blood vessel wall during the push process, reduces the risk of blood vessel penetration, dissection and vasospasm, and improves intraoperative hemodynamic stability; its inner lumen remains smooth and unobstructed, ensuring the smoothness of instrument delivery and structural support; the length, density and layout of the through holes 2 can be adjusted according to the interventional path and surgical procedure requirements, achieving precise control of compliance performance, taking into account both pushability and dimensional stability, and improving the controllability and safety of surgical operation.

[0033] The above description is merely a preferred embodiment of the present invention. However, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention should be covered within the scope of protection of the present invention.

Claims

1. An etched tube, characterized in that, include: The etched tube body has multiple rows of through holes along its axial direction from the inlet end to the outlet end, with each row having multiple through holes to improve flexibility and conformability.

2. The etched tube according to claim 1, characterized in that, At least four through holes should be opened.

3. The etched tube according to claim 1, characterized in that, Four through holes are made.

4. An etched tube according to claim 1, characterized in that, Each row of through holes can be straight, spiral, or staggered.

5. An etched tube according to any one of claims 1-4, characterized in that, The material of the etched tube body is polytetrafluoroethylene.

6. A method for preparing an etched tube according to any one of claims 1-5, characterized in that, Includes the following steps: Step (1): Insert a metal core rod that matches the inner wall size into the etched tube body and fit it tightly against the inner wall of the etched tube body. Step (2): Make holes in the outer wall of the etched tube body.

7. The method for preparing an etched tube according to claim 6, characterized in that, In step (2), a laser cutting device is used to make the hole.

8. A microcatheter, characterized in that, It includes an outermost sheath, a middle metal braided layer, and an outermost etched tube, wherein the etched tube is the etched tube according to any one of claims 1-5.

9. The application of the etched tube according to any one of claims 1-5 in a microcatheter.

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