Intermediate conduit
By setting an adjustment balloon in the second bend of the intermediate catheter, the stiffness can be dynamically adjusted, which solves the problem of insufficient stiffness of the intermediate catheter, improves the stability and controllability of the catheter in curved blood vessels, and avoids vascular deformation and damage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-22
- Publication Date
- 2026-03-13
AI Technical Summary
Existing intermediate catheters lack sufficient rigidity and have limited support performance, making it impossible to form a stable anchor point. This results in unreliable access establishment, and the catheters are prone to retraction or displacement when the blood vessel is bent, which may even cause vascular deformation or damage.
Design an intermediate conduit, including a first curved section, an intermediate isolation section and a second curved section arranged sequentially from distal to proximal. The second curved section is provided with an adjustment bladder, into which a pressure-adjustable medium can be introduced to achieve a filling and contraction state. When the adjustment bladder is in the filling state, it increases the stiffness of the second curved section, and when it is in the contraction state, it restores the preset curvature. The stiffness of the second curved section is dynamically adjusted by the state transition of the adjustment bladder.
It improves the controllability and path stability of the intermediate catheter, reduces the risk of kinking and vascular injury in tortuous blood vessels, and ensures that the aspiration catheter has stable path guidance in complex anatomical structures, reducing backtracking or positional deviation.
Smart Images
Figure CN121648441A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of medical device technology, and more particularly to an intermediate catheter. Background Technology
[0002] In thrombectomy, aspiration catheters are typically used in conjunction with long sheaths or intermediate catheters. The long sheath or intermediate catheter provides propulsion and support for the aspiration catheter. Compared to long sheaths, intermediate catheters have the advantage of a smaller outer diameter, allowing for some degree of flexible navigation. However, the support performance of intermediate catheters is limited. During advancement, they often fail to form stable anchor points, resulting in unreliable pathway establishment. This leads to a lack of stable path guidance for the aspiration catheter, making it difficult to navigate curved anatomical structures and prone to regression or positional deviation. If the overall rigidity of the intermediate catheter is designed to be too high, it can cause kinking and loss of pathway capability within curved vessels, potentially leading to vascular deformation or even damage when entering complex vascular anatomy. Summary of the Invention
[0003] The purpose of this invention is to provide an intermediate conduit that can solve the problems of insufficient rigidity, limited support performance, inability to form stable anchor points, and unreliable passage establishment of existing intermediate conduits.
[0004] To achieve this objective, the present invention adopts the following technical solution: An intermediate catheter is provided, comprising a first curved section, an intermediate isolation section, and a second curved section arranged sequentially from distal to proximal. The stiffness of the intermediate isolation section is less than the stiffness of the first curved section and the stiffness of the second curved section. At least a portion of the first curved section has a curvature, and at least a portion of the second curved section has a curvature. The second curved section is provided with an adjustment bladder, the length of which extends along the length direction of the second curved section and covers at least a portion of the circumference of the second curved section. The adjustment bladder is capable of being circulated with a pressure-adjustable medium to have a filled state and a contracted state. In the filled state, the adjustment bladder is configured to reduce the curvature of the second curved section.
[0005] In one embodiment, the regulating bladder is connected to the outer wall of the second curved section; or, The second curved section includes a second polymer layer and at least one second inner tube layer arranged radially from the outside to the inside, and the regulating bladder is sandwiched between the second polymer layer and the second inner tube layer.
[0006] In one embodiment, the intermediate catheter further includes a media injection tube communicating with the proximal end of the regulating balloon. The media injection tube is used to inject media into the regulating balloon or to drain media from the regulating balloon. The intermediate catheter also includes a straight section connected to the proximal end of the second curved section. Wherein, the regulating bladder is connected to the outer wall of the second curved section, and the medium injection pipe is connected to the outer wall of the straight section; or, The second curved section includes a second polymer layer and at least one second inner tube layer arranged radially from the outside to the inside. The straight section includes a third polymer layer and at least one third inner tube layer arranged radially from the outside to the inside. The regulating bladder is sandwiched between the second polymer layer and the second inner tube layer. The medium injection tube is sandwiched between the third polymer layer and the third inner tube layer.
[0007] In one embodiment, the second curved segment has an outer curved side and an inner curved side located on both sides of the central axis, and the adjusting bladder is disposed on the outer curved side. Along the circumference of the second curved segment, the central angle of the adjusting bladder is 90°~180°; and / or, The difference between the length of the second curved section and the length of the adjusting bladder is 0.5 mm to 1 mm; and / or, Along the central axis perpendicular to the second curved segment, the cross-sectional thickness of the adjusting bladder is 0.1 mm to 0.2 mm; and / or, Along the central axis perpendicular to the second curved section, the wall thickness of the regulating bladder is 0.02mm to 0.1mm.
[0008] In one embodiment, the material of the regulating capsule is a semi-permeable membrane, and the medium is a hypotonic solution.
[0009] In one embodiment, the outer surface of the regulating bladder is coated with a hydrophilic coating; and / or, The concentration of the hypotonic solution can be varied.
[0010] In one embodiment, the regulating bladder is a solid bladder, and the material of the regulating bladder is hydrogel.
[0011] In one embodiment, the second curved segment has an outer curved side and an inner curved side located on both sides of the central axis, and the intermediate conduit further includes two first radiopaque rings disposed on the second curved segment. The length of the first radiopaque ring extends circumferentially along the second curved segment, and the central angle of the first radiopaque ring is not greater than 180°. The two first radiopaque rings are symmetrically arranged with respect to the central axis of the first radiopaque ring, and the two first radiopaque rings are respectively disposed on the outer curved side and the inner curved side. The widths of the two first radiopaque rings are different; and / or, The intermediate conduit also includes at least one second radiopaque ring, which is disposed at the distal end of the first curved section and / or the second curved section.
[0012] In one embodiment, the first curved segment includes a first polymer layer, at least one reinforcing layer, and a first inner liner layer arranged radially from the outside to the inside, wherein the reinforcing layer is a spring layer or a braided layer; and / or, The first curved segment is formed by thermoplastic molding to achieve a first preset curvature.
[0013] In one embodiment, the ratio of the stiffness of the intermediate isolation section to the stiffness of the second bending section is 0.5 to 0.7.
[0014] In one embodiment, the second curved segment includes a second polymer layer and a second inner tube layer arranged radially from the outside to the inside, the second inner tube layer including at least one reinforcing layer and a second inner liner layer, the reinforcing layer being a spring layer or a braided layer; and / or The second curved segment is formed into a second preset curvature by thermoforming.
[0015] The beneficial effects of this invention are: The intermediate conduit provided by this invention includes a first curved section, an intermediate isolation section, and a second curved section arranged sequentially from distal to proximal. The stiffness of the intermediate isolation section is less than the stiffness of the first and second curved sections. At least a portion of the first and second curved sections have a curvature, and at least a portion of the second curved section also has a curvature. The second curved section is provided with an adjustment bladder, the length of which extends along the length direction of the second curved section and covers at least a portion of its circumference. The adjustment bladder can be circulated with a pressure-adjustable medium to have both a filled and a contracted state. In the filled state, the adjustment bladder is configured to reduce the curvature of the second curved section. Through this configuration, the intermediate isolation section reduces the coupling effect of bending moment and torque, allowing the stiffer first and second curved sections to respond independently during pushing or rotating operations of the intermediate conduit, thereby improving the controllability and path stability of the intermediate conduit. In its inflated state, the regulating balloon increases the local wall thickness and membrane tension in the second curved segment, thereby improving the bending stiffness of the second curved segment and straightening it to a certain extent, facilitating its insertion. In its contracted state, the membrane tension of the regulating balloon disappears, and the second curved segment returns to its preset curvature, achieving reversible adjustment of its bending stiffness. This avoids setting the bending stiffness of the second curved segment too high, preventing the intermediate catheter from becoming kinked within the curved vessel due to excessive stiffness, and reducing the risk of vascular deformation or even damage when the intermediate catheter enters complex vascular anatomy. During the insertion of the intermediate catheter, the first curved segment continuously provides guidance and path positioning. The inflated regulating balloon provides high stiffness to the second curved segment, offering stable support and facilitating insertion. After insertion, the regulating balloon contracts, and the second curved segment returns to its preset curvature, achieving compliance and better automatically adapting to the curved shape of the vessel. This provides stable support during the positioning phase, establishing a reliable pathway and ensuring the aspiration catheter has stable path guidance, enabling it to better navigate curved anatomical structures and reducing the risk of regression or positional deviation. Attached Figure Description
[0016] Figure 1 This is a cross-sectional view of the intermediate conduit described in Embodiment 1 of the present invention; Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle; Figure 3 yes Figure 1 A cross-sectional view of the intermediate conduit along a structure perpendicular to the central axis; Figure 4 This is a cross-sectional structural schematic diagram of another intermediate conduit in Embodiment 1 of the present invention; Figure 5 yes Figure 4 A magnified view of a portion of point B in the middle; Figure 6 yes Figure 4A cross-sectional view of the intermediate conduit along a structure perpendicular to the central axis; Figure 7 yes Figure 1 The second curved section is shown in a cross-sectional view of the structure when the regulating bladder is in a contracted state; Figure 8 yes Figure 1 A cross-sectional view of the second curved section in the structure when the regulating bladder is in a fully inflated state; Figure 9 yes Figure 4 The second curved section is shown in a cross-sectional view of the structure when the regulating bladder is in a contracted state; Figure 10 yes Figure 4 A cross-sectional view of the second curved section in the structure when the regulating bladder is in a fully inflated state; Figure 11 This is a schematic diagram of the structure of the first developing ring and the second developing ring as described in Embodiment 1 of the present invention; Figure 12 This is a schematic diagram of the method of using the intermediate conduit described in Embodiment 4 of the present invention. Figure 1 ; Figure 13 This is a schematic diagram of the method of using the intermediate conduit described in Embodiment 4 of the present invention. Figure 2 .
[0017] In the picture: 10. First curved section; 11. First polymer layer; 12. Reinforcing layer; 121. First reinforcing layer; 122. Second reinforcing layer; 13. First inner liner layer; 20. Intermediate isolation section; 30. Second curved section; 31. Outer curved side; 32. Inner curved side; 33. Second polymer layer; 34. Second inner tube layer; 341. Reinforcing layer; 3411. First reinforcing layer; 3412. Second reinforcing layer; 342. Second inner liner layer; 40. Adjustment bladder; 50. Media injection tube; 60. Straight tube section; 61. Third polymer layer; 62. Third inner tube layer; 71. First developing ring; 72. Second developing ring; 100. Aspiration catheter. Detailed Implementation
[0018] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0019] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0023] Example 1 like Figures 1 to 6As shown, an embodiment of the present invention provides an intermediate conduit, which includes a first curved section 10, an intermediate isolation section 20, and a second curved section 30 arranged sequentially from distal to proximal. The stiffness of the intermediate isolation section 20 is less than the stiffness of the first curved section 10 and the second curved section 30. At least a portion of the first curved section 10 and at least a portion of the second curved section 30 have a curved arc. The second curved section 30 is provided with an adjustment bladder 40, the length of which extends along the length direction of the second curved section 30 and covers at least a portion of the circumferential direction of the second curved section 30. The adjustment bladder 40 can be filled with a pressure-adjustable medium to have a filled state and a contracted state. The adjustment bladder 40 in the filled state is configured to reduce the curvature of the second curved section 30.
[0024] Through the above configuration, the intermediate isolation section 20 reduces the coupling effect of bending moment and torque, allowing the first bending section 10 and the second bending section 30, which have greater stiffness, to respond independently during the pushing or rotating operation of the intermediate catheter, thereby improving the controllability and path stability of the intermediate catheter. In the inflated state, the regulating balloon 40 generates a local increase in wall thickness and membrane tension in the second bending section 30, thereby increasing the bending stiffness of the second bending section 30 and straightening it to a certain extent, facilitating pushing. In the contracted state, the membrane tension of the regulating balloon 40 disappears, and the second bending section 30 returns to the second preset bending arc, better conforming to the curved shape of the blood vessel, providing stable fixation and support. Through the reversible adjustment of the bending stiffness of the second bending section 30, it is not necessary to set the bending stiffness of the second bending section 30 too high, avoiding the intermediate catheter from becoming kinked in the curved blood vessel due to excessive stiffness, and also reducing the risk of vascular deformation or even damage when the intermediate catheter enters complex vascular anatomy. During the insertion of the intermediate catheter, the first curved segment 10 continuously provides guidance and path positioning functions; the adjustment balloon 40 in the inflated state makes the second curved segment 30 more rigid and provides a stable support state, which facilitates insertion; after insertion is completed, the adjustment balloon 40 contracts, and the second curved segment 30 returns to the second preset curvature, achieving compliance and better automatically adapting to the curved shape of the blood vessel, thereby providing stable support during the positioning stage, establishing a reliable pathway, and enabling the aspiration catheter 100 to have stable path guidance, better pass through curved anatomical structures, and reduce the risk of regression or positional deviation.
[0025] In this embodiment, the regulating bladder 40 is connected to the outer wall of the second curved section 30, such as... Figure 3 and Figure 4 As shown, the regulating bladder 40 is fixed to the outer wall of the second curved section 30 by bonding or welding. The processing technology is simple and the maintainability is good.
[0026] In another embodiment, the second curved section 30 includes a second polymer layer 33 and at least one second inner tube layer 34 arranged radially from the outside to the inside. Figure 1 and Figure 2 As shown, the regulating bladder 40 is sandwiched between the second polymer layer 33 and the second inner tube layer 34, and a bladder is formed on the inner tube wall of the second polymer layer 33 by integral molding.
[0027] To facilitate the state transition of the regulating balloon 40, the intermediate catheter also includes a media injection tube 50, which is connected to the proximal end of the regulating balloon 40. The distal end of the regulating balloon 40 is heat-sealed, and the proximal end is used to inject media into the regulating balloon 40 through the media injection tube 50, or the media injection tube 50 is used to discharge media from the regulating balloon 40, thereby facilitating the transition of the regulating balloon 40 between an inflated and a contracted state.
[0028] In this embodiment, the intermediate catheter further includes a straight tube section 60, which is connected to the proximal end of the second curved section 30. The adjustment bladder 40 is connected to the outer wall of the second curved section 30, and the media injection tube 50 is connected to the outer wall of the straight tube section 60, which provides support for the media injection tube 50.
[0029] Alternatively, in another embodiment, the straight pipe section 60 includes a third polymer layer 61 and at least one third inner tube layer 62 arranged radially from the outside to the inside. For the structure in which the regulating bladder 40 is sandwiched between the second polymer layer 33 and the second inner tube layer 34, the medium injection pipe 50 is also sandwiched between the third polymer layer 61 and the third inner tube layer 62 to ensure the smooth flow of the medium.
[0030] The media injection tube 50 can be made of materials such as PI (polyimide) or nylon. The inner diameter of the media injection tube 50 is 0.05mm to 0.3mm. For example, the inner diameter of the media injection tube 50 is 0.1mm. The proximal end of the media injection tube 50 is connected to a Y-type valve or a Luer connector to control the discharge and inlet of the regulating bladder 40, thereby realizing the switching between the inflated and contracted states of the regulating bladder 40.
[0031] The second curved section 30 has an outer curved side 31 and an inner curved side 32 located on both sides of the central axis, with the adjusting bladder 40 disposed on the outer curved side 31. The central angle of the adjusting bladder 40 is 90°~180° along the circumference of the second curved section 30. When inflated, the adjusting bladder 40 generates a membrane tension F along the outer arc direction, which extends along the outer curved side 31, effectively applying an axial preload to the outer curved side 31 of the intermediate conduit. This preload generates a reverse additional bending moment, thereby resisting the bending deformation of the outer curved side 31 and producing a "straightening support" effect. Therefore, when the adjusting bladder 40 is inflated, the overall stiffness of the second curved section 30 is significantly improved, the intermediate conduit tends to straighten, and it can be used as a support structure, such as... Figure 8 and Figure 10 As shown; when the regulating bladder 40 is in the contracted state, the bending stiffness of the second bending segment 30 is restored, and the second bending segment 30 returns to the preset plastic bending shape. The second bending segment 30 is used for guiding and positioning, as shown. Figure 7 and Figure 9 As shown.
[0032] By adjusting the state of the bladder 40, the stiffness of the second curved section 30 can be dynamically adjusted without changing the structure of the intermediate catheter. In the inflated state, it forms a straight support, and in the contracted state, it returns to its plastic bending shape. During operation, the first curved section 10 continuously provides guidance and path positioning functions, while the second curved section 30 is supported and fixed when necessary by adjusting the inflated state of the bladder 40. Thus, with the bending radius of the second curved section 30 controllable, the stability of the pathway and the support effect during the pushing of the aspiration catheter 100 are significantly improved. During the use of the intermediate catheter, when the first curved segment 10 is used for guidance of the aortic arch or proximal tortuous structures, the bending angle of the second curved segment 30 can be straightened from the initial second preset bending arc to 15° by adjusting the inflation state of the balloon 40. This reduces the moment transmission and mutual interference between the first curved segment 10 and the second curved segment 30, facilitating arch crossing and guidance operations. After the first curved segment 10 completes its guidance function, the adjusting balloon 40 is contracted, and the second curved segment 30 returns to the second preset bending arc of 60°~90°, providing stable support for the outer curved side 31 during the positioning phase.
[0033] Furthermore, the inflated regulating bladder 40 causes a local bulge on the outer bending side 31 of the second bending section 30, effectively increasing the effective wall thickness of the second bending section 30. Since the outer bending side 31 is far from the central axis, the influence factor of the regulating bladder 40 on the bending stiffness of the second bending section 30 exhibits a square or even cubic relationship. Therefore, even a small increase in thickness can significantly improve the bending resistance of the second bending section 30. Taking an intermediate conduit with an outer diameter of 2.5 mm as an example, when the local wall thickness on the outer bending side 31 increases by 0.2 mm, the theoretical bending stiffness can be increased by approximately 30% to 35%.
[0034] The difference between the length of the second bending section 30 and the length of the adjusting bladder 40 is 0.5mm~1mm. In the length direction, the length of the second bending section 30 is slightly greater than the length of the adjusting bladder 40. The adjusting bladder 40 covers the second bending section 30 more comprehensively, ensuring that the adjusting bladder 40 in the inflated state causes the entire second bending section 30 to change stiffness, and does not affect the adjacent intermediate isolation section 20.
[0035] Along the direction perpendicular to the central axis of the second curved section 30, the cross-sectional thickness of the regulating bladder 40 is 0.1 mm to 0.2 mm. This thickness range includes both the contracted and inflated states. That is, the cross-sectional thickness of the regulating bladder 40 in the contracted state is not less than 0.1 mm, and the cross-sectional thickness of the regulating bladder 40 in the inflated state is not greater than 0.2 mm.
[0036] Along the direction perpendicular to the central axis of the second curved section 30, the wall thickness of the regulating bladder 40 is 0.02mm~0.1mm. The bladder material of the regulating bladder 40 can be any of TPU (thermoplastic polyurethane elastomer), TPE (thermoplastic polyester elastomer), polyamide, polyimide, elastic polyurethane, nylon, PET (polyethylene terephthalate), polytetrafluoroethylene, perfluoroethylene propylene copolymer, and polyetheretherketone, preferably polyurethane film (PU) or Pebax film.
[0037] The first curved section 10 includes a first polymer layer 11, at least one reinforcing layer 12, and a first inner liner layer 13 arranged radially from the outside to the inside. The reinforcing layer 12 is either a spring-loaded layer or a braided layer. The first polymer layer 11 can be made of any one of TPU (thermoplastic polyurethane), TPE (thermoplastic elastomer), polyamide, polyimide, elastic polyurethane, nylon, PET (polyethylene terephthalate), polytetrafluoroethylene, perfluoroethylene-propylene copolymer, or polyetheretherketone; preferably, TPU (thermoplastic polyurethane) is used as the material for the first polymer layer 11. The length of the first curved section 10 is 2cm to 10cm, preferably 2cm to 5cm.
[0038] Figure 1 and Figure 4 The diagram shows two reinforcing layers 12, namely a first reinforcing layer 121 and a second reinforcing layer 122. The first reinforcing layer 121 is a spring-loaded layer, and the second reinforcing layer 122 is a braided layer. The braided layer can be formed by weaving NiTi (nickel-titanium alloy) wire, stainless steel wire, or high-strength polymer wire, etc. The braided wire can be flat or round. For flat wire, the preferred width is 0.02mm~0.05mm and the thickness is 0.01mm~0.04mm; for round wire, the preferred diameter is 0.02mm~0.08mm; the braiding angle is 35°~55°, and the braiding angle can be adjusted according to the required flexibility of the second reinforcing layer 122, with a preferred braiding angle of 45°. The spring layer can be made of stainless steel wire or nickel-titanium alloy wire with a diameter of 0.05mm~0.08mm and a pitch of 0.05mm~0.10mm to ensure the bending resistance of the first reinforcing layer 121 while taking into account its flexibility; the spring layer can be wound clockwise or counterclockwise to form good anti-torsion and anti-kink properties.
[0039] In other embodiments, three or more reinforcing layers 12 may be used; or, where stiffness permits, the wall thickness of the first bending section 10 may be reduced by using only one reinforcing layer 12 and reducing the thickness of the reinforcing layer 12, thereby improving the passage of the intermediate conduit. The first inner liner 13 may be made of materials such as PTFE (polytetrafluoroethylene), FEP (fluorinated ethylene propylene copolymer), TPE (thermoplastic polyester elastomer), TPU (thermoplastic polyurethane elastomer), PEBAX (polyetheramide elastomer), PEEK (polyether ether ketone), etc., and preferably uses polymer materials such as PTFE film to reduce the wall thickness of the first bending section 10.
[0040] After the rheological processing of the first curved segment 10 is completed, a thermoforming mold (a mandrel of a specified shape) is inserted into the first curved segment 10 for shaping, forming the first preset curvature through thermoforming. Specifically, the shaping temperature is 150℃~250℃, and the shaping time is 2min~8min. The first curved segment 10 can be shaped into different shapes to meet the access and vascular anatomy requirements of various surgeries. Depending on the use requirements of the intermediate catheter, the first curved segment 10 can be shaped into the following typical shapes and similar shapes: SIM shape (Simons 1, 2, 3 types), suitable for different aortic arch anatomy, commonly used in intracranial thrombectomy; MP shape (Multipurpose), a small bend at the distal end of the first curved segment 10, facilitating access to multi-branch vessels; H1 shape (Headhunter 1 type), suitable for carotid arch and vertebral artery access; BER shape (Bern shape), suitable for vertebral artery and vascular anatomy with special curvature angles; and trans-curve shape (J-curve, etc.), suitable for different access methods such as transradial / transfemoral approaches. By changing the shape of the heat-setting mold, the first bending section 10 can be molded into the above-mentioned different shapes.
[0041] The ratio of the stiffness of the intermediate isolation section 20 to the stiffness of the second bending section 30 is 0.5 to 0.7. With a relatively low stiffness, the intermediate isolation section 20, while maintaining flexural strength and channel integrity, structurally dampens the moment transmission between the first bending section 10 and the second bending section 30, reducing moment and torque coupling between them. This ensures that the second bending section 30 is not prematurely bent due to the influence of the first bending section 10 during the introduction phase of the intermediate conduit. The intermediate isolation section 20 has a multi-layered structure arranged radially from the outside to the inside, including at least an outer polymer layer, an intermediate reinforcing layer, and an inner layer. The stiffness of the intermediate isolation section 20 is reduced to achieve flexibility, which can be achieved through one or more of the following methods: controlling the material hardness of the outer polymer layer, for example, using a block polyether phthalamide polymer with a Shore hardness of 35D~40D; reducing the wall thickness, for example, reducing the wall thickness relative to the first bending section 10 or the second bending section 30 by 0.02mm~0.04mm; and reducing the braiding coverage density, for example, reducing the braiding density PPI by 15%–30%.
[0042] A smaller coiled spring pitch can be provided in the intermediate reinforcing layer of the intermediate isolation section 20 to prevent cavity collapse; alternatively, an intermediate reinforcing layer with axial continuity or directional support capabilities, such as heat-treated shaping wire, can be provided in the intermediate isolation section 20 to form the necessary rigidity and stability. The intermediate reinforcing layer helps the intermediate isolation section 20 remain stable during bending and rotation, ensuring its precise guidance and shape retention, especially in complex paths and torsional operations. In one embodiment, the length of the intermediate isolation section 20 is 3 to 6 times its outer diameter.
[0043] The second curved section 30 includes a second polymer layer 33 and a second inner tube layer 34 arranged radially from the outside to the inside. The second inner tube layer 34 includes at least one reinforcing layer 341 and a second inner liner layer 342. For the structure where the adjusting bladder 40 is disposed inside the second polymer layer 33, the adjusting bladder 40 is sandwiched between the second polymer layer 33 and the reinforcing layer 341. The length of the second curved section 30 is 1cm to 6cm; this embodiment does not impose a specific limitation and can be adjusted according to usage requirements. The material of the second polymer layer 33 can be the same as the material of the first polymer layer 11, or the material of the second polymer layer 33 can be a polymer material with higher hardness. For example, the material of the first polymer layer 11 has a Shore hardness of 40D or 55D, and the material of the second polymer layer 33 has a Shore hardness of 63D, 72D, or 74D. Exemplarily, the reinforcing layer 341 includes a first reinforcing layer 3411 and a second reinforcing layer 3412 arranged sequentially from the outside to the inside. Similar to the first bending section 10, the first reinforcing layer 3411 is a spring-wound layer, and the second reinforcing layer 3412 is a braided layer. The braided layer can be formed by weaving NiTi (nickel-titanium alloy) wire, stainless steel wire, or high-strength polymer wire; the braided wire can be flat wire or round wire; the spring-wound layer can be made of stainless steel wire or nickel-titanium alloy wire.
[0044] After the rheological processing of the second curved segment 30 is completed, it is also shaped by inserting a thermoforming mold (a mandrel of a specified shape) into the second curved segment 30, forming the second preset curvature through thermoforming. Specifically, the shaping temperature is 150℃~250℃, and the shaping time is 2min~8min. Depending on the size of the second preset curvature, the second curved segment 30 can be shaped into three forms: a regular small curve (30°~45°), a medium curve (60°~75°), and a large curve (90°), which can be configured according to different anatomical needs. In addition, the second curved segment 30 can also be shaped into any of the following: a single-segment curve, which is more common and can form a clear support point; a double curve (S-shaped, J-shaped), which has two continuous curved segments and can be used for special anatomy (vertebral artery, stenotic bifurcation, etc.). By changing the mold shape, the second curved segment 30 can be shaped into the above different forms. For the double-curvature shape, each curved segment is individually equipped with an adjustment bladder 40, and the adjustment bladder 40 is set on the outer curved side 31 of the curved segment.
[0045] To distinguish the outer curved side 31 and the inner curved side 32, the second curved section 30 has an outer curved side 31 and an inner curved side 32 located on both sides of the central axis, respectively. The intermediate conduit also includes two first radiopaque rings 71, which are disposed in the second curved section 30. The length of the first radiopaque ring 71 extends circumferentially along the second curved section 30, and the central angle of the first radiopaque ring 71 is not greater than 180°. The two first radiopaque rings 71 are symmetrically arranged with respect to the central axis of the first radiopaque ring 71, and are respectively disposed on the outer curved side 31 and the inner curved side 32. The widths of the two first radiopaque rings 71 are different. For example, in this embodiment, the wider first radiopaque ring 71 is disposed on the outer curved side 31, and the narrower first radiopaque ring 71 is disposed on the inner curved side 32. Since the central angle of the first radiopaque ring 71 is not greater than 180°, there is a gap between the ends of the two first radiopaque rings 71. Figure 11 When observing the intermediate catheter, by rotating the intermediate catheter, if the lengths of the two first imaging rings 71 are the same within the line of sight, it indicates that the outer curved side 31 is on the upper side and the inner curved side 32 is on the lower side, thereby determining the direction of curvature and better fitting the target blood vessel.
[0046] The intermediate catheter also includes at least one second imaging ring 72, which is disposed at the distal end of the first curved segment 10 and / or the second curved segment 30. The first curved segment 10 may have one or more second imaging rings 72 to facilitate the operator in determining the specific location of the distal end of the first curved segment 10. The second curved segment 30 may also have one or more second imaging rings 72. When two second imaging rings 72 are provided, one second imaging ring 72 can be provided at both the proximal and distal ends of the second curved segment 30 to clearly show the spatial extent of the second curved segment 30 and the coverage area of the capsule. The second imaging ring 72 can be a whole ring or a strip.
[0047] Example 2 Embodiment 2 of the present invention provides an intermediate conduit, which has the same first curved section 10, intermediate isolation section 20 and second curved section 30 as in Embodiment 1. The stiffness of the intermediate isolation section 20 is less than the stiffness of the first curved section 10 and the second curved section 30. At least a portion of the first curved section 10 has a curvature, and at least a portion of the second curved section 30 has a curvature. The second curved section 30 is provided with an adjustment bladder 40, the length of which extends along the length direction of the second curved section 30 and covers at least a portion of the circumferential direction of the second curved section 30. The adjustment bladder 40 can be filled with a pressure-adjustable medium to have a filled state and a contracted state. The adjustment bladder 40 in the filled state is configured to reduce the curvature of the second curved section 30.
[0048] The beneficial effects of the first curved section 10, the intermediate isolation section 20, and the second curved section 30 are as described in Embodiment 1. This Embodiment 2 will not repeat the similarities. The difference in Embodiment 2 is that the material of the regulating capsule 40 is a semi-permeable membrane, and the medium inside the capsule is a hypotonic solution. The hypotonic solution permeates through the semi-permeable membrane to achieve the filling and contraction states of the regulating capsule 40. For example, the hypotonic solution is distilled water or a solution containing trace amounts of glycerol, and the osmotic pressure of the hypotonic solution is less than 100 mosm / kg. In an in vitro environment, such as in air, the regulating capsule 40 is filled through injection or permeation. At this time, the overall bending stiffness of the intermediate conduit is high, facilitating insertion and positioning. After entering the blood vessels, the regulating capsule 40 comes into contact with the blood. Since the osmotic pressure of blood is approximately 300 mosm / kg, which is higher than the osmotic pressure of the hypotonic solution inside the regulating capsule 40, water molecules in the hypotonic solution permeate outwards through the semi-permeable membrane. The pressure of the regulating capsule 40 gradually decreases, its volume shrinks, and it enters a contracted state. The second curved section 30 then returns to its original second preset curvature, thereby achieving compliance and automatic adaptation to blood vessel curvature within the body. In this embodiment, the filling and contracting states of the regulating capsule 40 do not require external control or a liquid injection device; the state transition is an adaptive control process, which is simpler.
[0049] The outer surface of the regulating capsule 40 is coated with a hydrophilic coating, such as a PTFE (polytetrafluoroethylene) microporous layer, to control the permeation rate of the hypotonic solution. The hydrophilic coating can increase the water flux of the regulating capsule 40 during permeation, so that the formation time of the contraction state is controlled within 1 min to 3 min, which meets the requirements of the intermediate catheter introduction speed and ensures that the second curved segment 30 will form a contraction state only when it reaches the target blood vessel.
[0050] In another embodiment, the formation time of the contraction state can also be controlled by changing the concentration of the hypotonic solution.
[0051] Example 3 Embodiment 3 of the present invention provides an intermediate conduit, which has the same first curved section 10, intermediate isolation section 20 and second curved section 30 as in Embodiment 1. The stiffness of the intermediate isolation section 20 is less than the stiffness of the first curved section 10 and the second curved section 30. At least a portion of the first curved section 10 has a curvature, and at least a portion of the second curved section 30 has a curvature. The second curved section 30 is provided with an adjustment bladder 40, the length of which extends along the length direction of the second curved section 30 and covers at least a portion of the circumferential direction of the second curved section 30. The adjustment bladder 40 can be filled with a pressure-adjustable medium to have a filled state and a contracted state. The adjustment bladder 40 in the filled state is configured to reduce the curvature of the second curved section 30.
[0052] The beneficial effects of the first curved section 10, the intermediate isolation section 20, and the second curved section 30 are as described in Example 1. This Example 3 will not repeat the similarities. The difference in this Example 3 is that the regulating bladder 40 is a solid bladder, and the material of the regulating bladder 40 is a hydrogel, such as PNIPAM (poly(N-isopropylacrylamide)) hydrogel. The hydrogel utilizes temperature changes to trigger swelling and contraction. The regulating bladder 40 expands at room temperature outside the body to form a full state, and can contract and release air at an ambient temperature of approximately 37°C inside the body to form a contracted state.
[0053] Example 4 This fourth embodiment provides a method for using an intermediate catheter, employing any of the intermediate catheters from embodiments one to three, and the intermediate catheter is used for path guidance in the aortic arch. For example... Figure 12 and Figure 13 As shown in the diagram, DA represents the descending aorta, AA represents the aortic arch, RCC represents the right coronary valve tip, LCC represents the left main coronary artery, and LSA represents the left subclavian artery.
[0054] First, the operator pre-inserts a guidewire into the target vascular access and, guided by the guidewire, advances the first curved segment 10 of the intermediate catheter along the aortic arch. Due to its pre-set curvature and flexibility, the first curved segment 10 can smoothly pass through the arch with guidewire assistance, achieving initial access establishment. Figure 12 As shown. Subsequently, the aspiration catheter 100 is advanced along the established pathway, with the soft segment of the aspiration catheter 100 entering the left subclavian artery (LSA) or its corresponding branch. At this point, the operator continues to advance the intermediate catheter, using the second imaging ring 72 for positioning and fluoroscopic guidance, advancing the second curved segment 30 along the guidewire to the aortic arch. Once the second curved segment 30 reaches the predetermined position, the operator releases the fluid pressure within the regulating balloon 40 (including release via the media injection tube 50 or osmotic self-release of a hypotonic solution), and the second curved segment 30 returns to its second preset curvature, with the outer curved side 31 naturally conforming to the outer wall of the aortic arch, thus forming a stable anchoring support in the arch. Because the second curved segment 30 has higher bending stiffness and deformation resistance than the first curved segment 10, it can provide continuous axial and radial support in the arch, preventing catheter retraction or dislodgement, such as... Figure 13 As shown. Under this stable support, the aspiration catheter 100 can continue to advance along the established pathway to the distal target lesion site for aspiration. Because the second curved section 30 of the intermediate catheter has formed a reliable arch support structure, the aspiration catheter 100 will not fall off the arch, retract, or collapse during the pushing and aspiration process, significantly improving pathway stability and operational safety.
[0055] Through the above-described method of use, the intermediate catheter provided by this invention can achieve a two-stage operation strategy of "guidance first, support later" in complex and tortuous vascular pathways such as the aortic arch. In the first stage, the first tortuous segment 10 provides compliant guidance and pathway establishment; in the second stage, the second tortuous segment 30 restores the second preset curvature and forms stable support after the adjustment balloon 40 is released. Thus, a reliable support point can be established in the aortic arch without the need for a long sheath, ensuring smooth advancement and stable operation of the aspiration catheter 100. The intermediate catheter in any of Embodiments 1 to 3 can effectively avoid the problems of "arc drop" and "retraction" in the aortic arch region, while reducing the risk of vascular damage caused by the use of a long sheath, and improving intraoperative pushing stability and aspiration efficiency.
[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. An intermediate conduit, characterized in that, The device includes a first curved section (10), an intermediate isolation section (20), and a second curved section (30) arranged sequentially from the distal end to the proximal end. The stiffness of the intermediate isolation section (20) is less than the stiffness of the first curved section (10) and the stiffness of the second curved section (30). At least a portion of the first curved section (10) has a curvature, and at least a portion of the second curved section (30) has a curvature. The second curved section (30) is provided with an adjustment bladder (40). The length of the adjustment bladder (40) extends along the length direction of the second curved section (30) and covers at least a portion of the circumference of the second curved section (30). The adjustment bladder (40) can be filled with a pressure-adjustable medium to have a filled state and a contracted state. In the filled state, the adjustment bladder (40) is configured to reduce the curvature of the second curved section (30).
2. The intermediate conduit according to claim 1, characterized in that, The regulating bladder (40) is connected to the outer wall of the second curved section (30); or, The second curved section (30) includes a second polymer layer (33) and at least one second inner tube layer (34) arranged radially from the outside to the inside, and the regulating bladder (40) is sandwiched between the second polymer layer (33) and the second inner tube layer (34).
3. The intermediate conduit according to claim 1, characterized in that, The intermediate conduit also includes a media injection tube (50), which is connected to the proximal end of the regulating bladder (40). The media injection tube (50) is used to inject media into the regulating bladder (40) or to discharge media from the regulating bladder (40). The intermediate conduit also includes a straight tube section (60), which is connected to the proximal end of the second curved section (30). Wherein, the regulating bladder (40) is connected to the outer wall of the second curved section (30), and the medium injection pipe (50) is connected to the outer wall of the straight section (60); or, The second curved section (30) includes a second polymer layer (33) and at least one second inner tube layer (34) arranged radially from the outside to the inside. The straight section (60) includes a third polymer layer (61) and at least one third inner tube layer (62) arranged radially from the outside to the inside. The regulating bladder (40) is sandwiched between the second polymer layer (33) and the second inner tube layer (34). The medium injection tube (50) is sandwiched between the third polymer layer (61) and the third inner tube layer (62).
4. The intermediate conduit according to claim 1, characterized in that, The second curved segment (30) has an outer curved side (31) and an inner curved side (32) located on both sides of the central axis, respectively. The adjusting bladder (40) is disposed on the outer curved side (31). Along the circumference of the second curved segment (30), the central angle of the adjusting bladder (40) is 90°~180°; and / or, The difference between the length of the second curved segment (30) and the length of the adjusting bladder (40) is 0.5 mm to 1 mm; and / or, Along the central axis perpendicular to the second curved segment (30), the cross-sectional thickness of the adjusting bladder (40) is 0.1 mm to 0.2 mm; and / or, Along the central axis perpendicular to the second curved section (30), the wall thickness of the regulating bladder (40) is 0.02 mm to 0.1 mm.
5. The intermediate conduit according to claim 1, characterized in that, The regulating capsule (40) is made of a semi-permeable membrane, and the medium is a hypotonic solution.
6. The intermediate conduit according to claim 5, characterized in that, The outer surface of the regulating bladder (40) is coated with a hydrophilic coating; and / or, The concentration of the hypotonic solution can be varied.
7. The intermediate conduit according to claim 1, characterized in that, The regulating bladder (40) is a solid bladder, and the material of the regulating bladder (40) is hydrogel.
8. The intermediate conduit according to any one of claims 1-7, characterized in that, The second curved section (30) has an outer curved side (31) and an inner curved side (32) located on both sides of the central axis. The intermediate conduit also includes two first imaging rings (71). The first imaging rings (71) are disposed in the second curved section (30). The length of the first imaging rings (71) extends circumferentially along the second curved section (30), and the central angle of the first imaging rings (71) is not greater than 180°. The two first imaging rings (71) are symmetrically arranged with respect to the central axis of the first imaging rings (71), and the two first imaging rings (71) are respectively disposed on the outer curved side (31) and the inner curved side (32). The widths of the two first imaging rings (71) are different; and / or, The intermediate conduit also includes at least one second radiopaque ring (72), which is disposed at the distal end of the first curved segment (10) and / or the second curved segment (30).
9. The intermediate conduit according to any one of claims 1-7, characterized in that, The first curved section (10) includes a first polymer layer (11), at least one reinforcing layer (12), and a first inner lining layer (13) arranged radially from the outside to the inside, wherein the reinforcing layer (12) is a spring-loaded layer or a braided layer; and / or, The first curved segment (10) is formed by thermoplastic molding to form a first preset curvature.
10. The intermediate conduit according to any one of claims 1-7, characterized in that, The ratio of the stiffness of the intermediate isolation section (20) to the stiffness of the second bending section (30) is 0.5 to 0.
7.
11. The intermediate conduit according to any one of claims 1-7, characterized in that, The second curved section (30) includes a second polymer layer (33) and a second inner tube layer (34) arranged radially from the outside to the inside. The second inner tube layer (34) includes at least one reinforcing layer (341) and a second inner lining layer (342). The reinforcing layer (341) is a spring-wound layer or a braided layer; and / or, The second curved segment (30) is formed into a second preset curved arc by thermoplastic molding.