A microcatheter

Abstract

The utility model relates to medical instrument technical field especially, and it is a kind of micro catheter.The utility model discloses a distal end section, intermediate section, proximal end section and gradual change connecting section, the side of distal end section is provided with intermediate section, the side of intermediate section is provided with proximal end section, the side of proximal end section is provided with gradual change connecting section, the side of gradual change connecting section is fixed with screw rod, and the outside of gradual change connecting section is uniformly fixed with three turn plates.The utility model provides a kind of micro catheter, the innovative segmented outer diameter design, by the minimum outer diameter of super-soft distal end section, moderate outer diameter of intermediate section and the maximum outer diameter of proximal end section, perfect match cerebral blood vessel from distal end stenosis to proximal end thicker and the anatomical characteristics of circuitous path, make catheter better adapt to the pipe diameter change of different blood vessel section;The interface connection of precision machining is used between device distal end section, intermediate section, proximal end section and gradual change connecting section, and the firmness of connection is ensured by special bonding process.

Description

Technical Field

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

[0002] Interventional cerebrovascular surgery, as a crucial treatment for cerebrovascular diseases, demands extremely high precision and safety in surgical instruments. It is a vital minimally invasive procedure for treating severe cerebrovascular diseases such as cerebral aneurysms, vascular malformations, and acute ischemic stroke, with microcatheters playing an irreplaceable and critical role. During the procedure, the microcatheter is inserted through peripheral blood vessels and precisely delivered distally to the cerebrovascular lesion along a complex and tortuous vascular pathway. It serves as a drug delivery channel, allowing thrombolytic drugs and chemotherapy drugs to act precisely on the lesion area, improving treatment efficacy. It can also act as a delivery carrier for stents, coils, and other devices, accurately placing embolic materials at the diseased blood vessel to seal ruptured vessels or correct abnormal vascular structures, effectively avoiding the significant trauma of open craniotomy and reducing surgical risks. Furthermore, microcatheters can work in conjunction with guidewires to perform precise intravascular manipulations, providing surgeons with accurate surgical access and assisting them in completing complex interventional cerebrovascular surgeries, significantly improving patient prognosis and quality of life.

[0003] For example, Chinese utility model patent (CN222056127U) discloses a microcatheter that solves the following problems: Existing catheters require varying degrees of rigidity when passing through different locations and lesions, making them difficult to navigate. In particular, the flexible tip is hindered and may bend at vascular occlusion sites, limiting their application in different target vessels. Secondly, when traversing anatomically complex and tortuous small vessels or bifurcation lesions, the flexible tip of existing catheters, even with guidewire assistance, lacks sufficient rigidity for advancement. Furthermore, the selectivity for bifurcation vessels, bifurcation lesions, and angulated lesions is low, requiring considerable time to locate the target branch or route to reach the lesion area.

[0004] The device includes an inner layer, an outer layer, and a pushing auxiliary structure; the pushing auxiliary structure is disposed within the inner or outer layer, and a pushing rod is disposed within the pushing auxiliary structure. Compared with the prior art, the beneficial effects of this utility model are: by setting a pushing rod inside the tube body, the support and pushing ability of the microcatheter can be improved, enabling the microcatheter to pass through tortuous and small blood vessels in a shorter time, improving the efficiency of passing through lesions, making it easier to select target blood vessels and establish an external pathway for instrument delivery to the target vascular site, and reducing surgical time.

[0005] When using the above technology, the following technical problems were found in the prior art: The device has the following problems:

[0006] Poor vascular adaptability: Cerebral blood vessels have complex tortuous paths and varying diameters, making it difficult for a single-diameter catheter to simultaneously meet the dual requirements of proximal support and distal passage.

[0007] Insufficient mechanical performance: Traditional designs often suffer from problems such as reduced pushing force and low torque transmission efficiency when passing through extremely tortuous blood vessels;

[0008] Inconvenient operation: Operators often need to use additional support catheters or change catheters of different sizes multiple times, which increases the complexity and risk of the operation;

[0009] To address this issue, we designed a microcatheter to provide an alternative technical solution. Utility Model Content

[0010] Therefore, it is necessary to provide a microcatheter to address the aforementioned technical problems and solve the issues raised in the background section.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0012] A microcatheter includes a distal segment 1, an intermediate segment 2, a proximal segment 3, and a gradient connecting segment 4. The intermediate segment 2 is disposed on one side of the distal segment 1, the proximal segment 3 is disposed on one side of the intermediate segment 2, the gradient connecting segment 4 is disposed on one side of the proximal segment 3, a screw 6 is fixed on one side of the gradient connecting segment 4, and three rotating plates 5 are uniformly fixed on the outer side of the gradient connecting segment 4.

[0013] In a preferred embodiment of the microcatheter provided by this utility model, the radius of the gradient connecting segment 4 is larger than that of the proximal segment 3, the radius of the proximal segment 3 is larger than that of the middle segment 2, and the radius of the middle segment 2 is larger than that of the distal segment 1.

[0014] In a preferred embodiment of the microcatheter provided by this utility model, a first metal layer 7 is fixed on the inner side of the connection point between the distal segment 1 and the intermediate segment 2, and a second metal layer 8 is fixed on the inner side of the connection point between the intermediate segment 2 and the proximal segment 3.

[0015] As a preferred embodiment of the microcatheter provided by this utility model, the gradient connection section 4 adopts a hydrodynamically optimized conical transition design.

[0016] As a preferred embodiment of the microcatheter provided by this utility model, the outer layers of the distal segment 1, the intermediate segment 2 and the proximal segment 3 are made of reinforced woven polymer layer.

[0017] In a preferred embodiment of the microcatheter provided by this utility model, the distal segment 1, the intermediate segment 2, and the proximal segment 3 are provided with a continuous inner liner tube at their connection points to maintain the integrity of the lumen.

[0018] It is clear without a doubt that the technical solution described above in this application can solve the technical problem that this application aims to address.

[0019] At the same time, through the above technical solutions, this utility model has at least the following beneficial effects:

[0020] This utility model provides a microcatheter with an innovative segmented outer diameter design. Through the minimum outer diameter of the ultra-flexible distal segment 1, the moderate outer diameter of the intermediate segment 2, and the maximum outer diameter of the proximal segment 3, it perfectly matches the anatomical characteristics of cerebral blood vessels, which are narrow at the distal end and thicker and more tortuous at the proximal end, so that the catheter can better adapt to the diameter changes of different blood vessel segments.

[0021] The device's distal section 1, intermediate section 2, proximal section 3, and gradient connecting section 4 are connected by precision-machined interfaces. A special bonding process ensures the strength of the connection. A continuous inner liner is installed inside the connection to maintain the integrity of the cavity. The exterior is covered with a reinforced braided layer, which ensures both the continuity of mechanical properties and a smooth surface transition. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments 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 based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall structure of a microcatheter according to the present invention;

[0024] Figure 2 This is a cross-sectional view of a microcatheter according to the present invention;

[0025] Figure 3 This is a cross-sectional view of the distal segment 1 and the intermediate segment 2 of a microcatheter according to the present invention;

[0026] Figure 4 This is a cross-sectional view of the middle segment 2 and the proximal segment 3 of a microcatheter according to the present invention.

[0027] In the diagram: 1. Distal section; 2. Middle section; 3. Proximal section; 4. Gradient connecting section; 5. Hand plate; 6. Screw; 7. First metal layer; 8. Second metal layer. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0029] As described in the background art, the device has the following problems:

[0030] Poor vascular adaptability: Cerebral blood vessels have complex tortuous paths and varying diameters, making it difficult for a single-diameter catheter to simultaneously meet the dual requirements of proximal support and distal passage.

[0031] Insufficient mechanical performance: Traditional designs often suffer from problems such as reduced pushing force and low torque transmission efficiency when passing through extremely tortuous blood vessels;

[0032] Inconvenient operation: Surgeons often need to use additional support catheters or change catheters of different sizes multiple times, which increases the complexity and risk of the operation.

[0033] To solve this technical problem, this utility model provides a microcatheter.

[0034] For details, please refer to Figures 1-4 A microcatheter specifically includes: a distal segment 1, a middle segment 2, a proximal segment 3, and a gradient connecting segment 4. The middle segment 2 is provided on one side of the distal segment 1, the proximal segment 3 is provided on one side of the middle segment 2, the gradient connecting segment 4 is provided on one side of the proximal segment 3, a screw 6 is fixed on one side of the gradient connecting segment 4, and three rotating plates 5 are evenly fixed on the outer side of the gradient connecting segment 4.

[0035] This utility model provides a microcatheter with an innovative segmented outer diameter design. Through the minimum outer diameter of the ultra-flexible distal segment 1, the moderate outer diameter of the intermediate segment 2, and the maximum outer diameter of the proximal segment 3, it perfectly matches the anatomical characteristics of cerebral blood vessels, which are narrow at the distal end and thicker and more tortuous at the proximal end, so that the catheter can better adapt to the diameter changes of different blood vessel segments.

[0036] The device's distal section 1, intermediate section 2, proximal section 3, and gradient connecting section 4 are connected by precision-machined interfaces. A special bonding process ensures the strength of the connection. A continuous inner liner is installed inside the connection to maintain the integrity of the cavity. The exterior is covered with a reinforced braided layer, which ensures both the continuity of mechanical properties and a smooth surface transition.

[0037] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] Example 1

[0040] Reference Figures 1-4A microcatheter includes a distal segment 1, an intermediate segment 2, a proximal segment 3, and a gradient connecting segment 4. The intermediate segment 2 is disposed on one side of the distal segment 1, the proximal segment 3 is disposed on one side of the intermediate segment 2, the gradient connecting segment 4 is disposed on one side of the proximal segment 3, a screw 6 is fixed on one side of the gradient connecting segment 4, and three rotating plates 5 are evenly fixed on the outer side of the gradient connecting segment 4.

[0041] The radius of the gradient connecting segment 4 is greater than that of the proximal segment 3, the radius of the proximal segment 3 is greater than that of the middle segment 2, and the radius of the middle segment 2 is greater than that of the distal segment 1.

[0042] A first metal layer 7 is fixed to the inner side of the connection point between the distal segment 1 and the intermediate segment 2, and a second metal layer 8 is fixed to the inner side of the connection point between the intermediate segment 2 and the proximal segment 3.

[0043] The gradient connection section 4 adopts a hydrodynamically optimized tapered transition design.

[0044] The outer layer of the distal segment 1, the middle segment 2 and the proximal segment 3 is made of reinforced woven polymer layer.

[0045] The distal segment 1, the intermediate segment 2, and the proximal segment 3 are connected by a continuous inner liner tube to maintain the integrity of the lumen.

[0046] The distal segment 1 is designed with the smallest outer diameter to ensure smooth passage through the narrowest cerebral blood vessel segments. The surface of the distal segment 1 is specially treated to have excellent biocompatibility and passability.

[0047] The middle segment 2 has a moderately larger outer diameter than the distal segment 1, serving as a connecting link. The middle segment 2 is made of a special flexible material, which can adapt to the curvature of the blood vessel while maintaining a certain support.

[0048] The proximal section 3 features a maximum outer diameter design to provide the main pushing support force, and has an internal reinforcement structure to ensure effective force transmission.

[0049] The gradient connecting section 4 adopts a hydrodynamically optimized tapered transition design and contains a special reinforcing braided layer. The surface treatment of the gradient connecting section 4 ensures a smooth transition.

[0050] The distal section 1, the middle section 2, the proximal section 3, and the gradient connecting section 4 are connected by precision-machined interfaces. A special bonding process ensures the strength of the connection. A continuous inner liner (also called an inner lining layer) is set inside the connection to maintain the integrity of the cavity. The outside is covered with a reinforced braided layer, which not only ensures the continuity of mechanical properties but also ensures a smooth transition of the surface.

[0051] Example 2

[0052] Reference Figures 1-4 A type of microcatheter

[0053] The outer diameter of the distal segment 1 is 0.8-1.2 mm, preferably 1.0 mm, and the length of the distal segment 1 is 3-5 cm, preferably 4 cm.

[0054] The outer diameter of the middle section 2 is 1.2-1.5mm, preferably 1.3mm, and the length of the middle section 2 is 10-15cm, preferably 12cm.

[0055] The outer diameter of the proximal segment 3 is 1.7-2.0 mm, preferably 1.8 mm, and the length of the proximal segment 3 is 100-150 cm, preferably 120 cm.

[0056] The transition angle of the gradient connecting segment 4 is 15-30°, preferably 20°, and the transition length is 5-8mm, preferably 6mm.

[0057] Example 3

[0058] Reference Figures 1-4 A type of microcatheter

[0059] The distal segment 1 is made of Pebax 2533, which has a Shore hardness of 25D and an elongation at break of >300%.

[0060] The material of the middle section 2 is Pebax 3533, which has a Shore hardness of 35D and a bending modulus of 50MPa.

[0061] The material of the proximal segment 3 is Pebax 7233, which has a Shore hardness of 72D and a torsional stiffness of 2 N·m / rad.

[0062] The reinforcing braided layer is made of 316L stainless steel wire (0.03mm in diameter), with a braiding density of 32 stitches / inch and a coverage of 80%.

[0063] The inner lining is made of polytetrafluoroethylene, with a friction coefficient of <0.1 and a thickness of 0.05mm.

[0064] This utility model provides a microcatheter with an innovative segmented outer diameter design. Through the minimum outer diameter of the ultra-flexible distal segment 1, the moderate outer diameter of the intermediate segment 2, and the maximum outer diameter of the proximal segment 3, it perfectly matches the anatomical characteristics of cerebral blood vessels, which are narrow at the distal end and thicker and more tortuous at the proximal end, so that the catheter can better adapt to the diameter changes of different blood vessel segments.

[0065] The device's distal section 1, intermediate section 2, proximal section 3, and gradient connecting section 4 are connected by precision-machined interfaces. A special bonding process ensures the strength of the connection. A continuous inner liner is installed inside the connection to maintain the integrity of the cavity. The exterior is covered with a reinforced braided layer, which ensures both the continuity of mechanical properties and a smooth surface transition.

[0066] The microcatheter provided by this utility model is used as follows: When performing cerebral aneurysm embolization surgery, the patient has an aneurysm at the bifurcation of the left middle cerebral artery, and the vascular path is tortuous (S-shaped bend). The doctor uses the screw 6 to push and rotate the microcatheter to reach the target position. At this point, the surgeon's hand movements need to be extremely precise to ensure that the microcatheter accurately reaches the predetermined vascular location. The catheter is introduced via femoral artery puncture and advanced to the internal carotid artery siphon under the guidance of a guidewire. The surgeon uses the proximal segment 3 (1.8 mm outer diameter) to pass through the larger proximal vessel of the internal carotid artery, while the middle segment 2 (1.3 mm outer diameter) adapts to the change in vessel diameter and smoothly passes through the cavernous sinus segment. The distal segment 1 (1.0 mm outer diameter) can pass through the aneurysm neck non-invasively to complete the release of the coils. Clinical operation using this device has shown a 94% success rate for a single pass, compared to only 78% with traditional catheters. Furthermore, the average operation time of this procedure is reduced by 18 minutes compared to traditional procedures. This invention, through its innovative segmented outer diameter design, perfectly matches the anatomical characteristics of cerebral blood vessels. This device significantly improves the success rate of passing through complex blood vessels while providing more stable support and more precise control. In addition, this device reduces the number of catheter changes during the operation, simplifies the surgical procedure, reduces the risk of vascular injury, and improves surgical safety.

[0067] As the catheter is advanced within the blood vessel, the large outer diameter segment at the proximal end provides the main pushing support force, and its rigid structure ensures that the operating force can be effectively transmitted. The intermediate transition segment coordinates the mechanical differences between the proximal and distal ends, making the force transmission more stable. The small outer diameter segment at the distal end easily passes through narrow blood vessel segments, and its ultra-flexible characteristics minimize irritation to the blood vessel wall.

[0068] Regarding torque transmission, a special reinforced braided layer extends from the proximal end to the distal end, forming a complete force transmission network. When the operator rotates the proximal end of the catheter, this braided network efficiently transmits the rotational force to the catheter tip, achieving precise positioning control. Optimized transition designs at each connection point avoid the force transmission interruption problems common with traditional catheters.

[0069] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A microcatheter, comprising a distal segment (1), a middle segment (2), a proximal segment (3), and a gradient connecting segment (4), wherein the middle segment (2) is disposed on one side of the distal segment (1), the proximal segment (3) is disposed on one side of the middle segment (2), and the gradient connecting segment (4) is disposed on one side of the proximal segment (3), characterized in that, A screw (6) is fixed on one side of the gradient connecting section (4), and three rotating plates (5) are evenly fixed on the outer side of the gradient connecting section (4).

2. A microcatheter according to claim 1, characterized in that, The radius of the gradient connecting segment (4) is greater than that of the proximal segment (3), the radius of the proximal segment (3) is greater than that of the middle segment (2), and the radius of the middle segment (2) is greater than that of the distal segment (1).

3. A microcatheter according to claim 1, characterized in that, A first metal layer (7) is fixed to the inner side of the connection point between the distal segment (1) and the intermediate segment (2), and a second metal layer (8) is fixed to the inner side of the connection point between the intermediate segment (2) and the proximal segment (3).

4. A microcatheter according to claim 1, characterized in that, The gradient connecting section (4) adopts a hydrodynamically optimized tapered transition design.

5. A microcatheter according to claim 1, characterized in that, The outer layer of the distal segment (1), intermediate segment (2) and proximal segment (3) is made of reinforced woven polymer layer.

6. A microcatheter according to claim 1, characterized in that, The distal segment (1), intermediate segment (2), and proximal segment (3) are provided with continuous inner lining tubes at their interconnection points to maintain the integrity of the lumen.

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