Microcatheter and interventional system

Abstract

This invention provides a microcatheter and interventional system. The microcatheter includes a composite welded inner layer and an outer layer. The composite welded inner layer includes a support core and a filling portion. The support core extends tubularly along the axial direction of the microcatheter and has a permeable structure along the radial direction of the microcatheter. The filling portion covers the inner side of the support core and fills the permeable structure. The outer layer covers the outer side of the composite welded inner layer. This configuration, through the composite welded inner layer covering the inner side of the support core and filling the permeable structure, eliminates the need for winding or braiding the inner tube in existing technologies, avoids wrinkles in the inner tube, simplifies the process, and improves the forming quality of the microcatheter. The microcatheter and interventional system provided by this invention are particularly suitable for irregularly shaped or variable-diameter microcatheters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a microcatheter and an interventional system. BACKGROUND

[0002] Percutaneous coronary intervention (PCI) is mainly used for the treatment of obstructive coronary artery disease. About 15% of obstructive coronary artery disease is chronic total occlusion (CTO), and CTO surgery often requires the use of a microcatheter.

[0003] The existing microcatheter production process is complicated, and the inner tube of the microcatheter is prone to wrinkle deformation during the forming process. The wrinkle deformation of the inner tube not only affects the forming of the outer tube, but also causes gaps that are difficult to fill inside, which further reduces the passability of the guide wire in the microcatheter cavity. In addition, the existing microcatheter production process has great difficulty in forming special-shaped microcatheters or variable-diameter microcatheters. SUMMARY

[0004] The purpose of the present application is to provide a microcatheter and an interventional system to solve the problem of existing microcatheters that are prone to inner tube wrinkles, resulting in forming defects.

[0005] To solve the above technical problems, the present application provides a microcatheter, which comprises: a composite fusion inner layer and an outer layer; the composite fusion inner layer comprises a support core and a filling part; the support core extends in a tubular shape along the axial direction of the microcatheter, and the support core has a through structure along the radial direction of the microcatheter, the filling part is wrapped on the inner side of the support core and filled in the through structure; the outer layer is wrapped on the outer side of the composite fusion inner layer.

[0006] Optionally, the filling part is filled in the through structure by melting and wrapped on the inner side of the support core by melting.

[0007] Optionally, the composite fusion inner layer is knitted and / or coiled based on a composite wire material.

[0008] Optionally, the composite wire material comprises a metal core material and a polymer layer wrapped outside the metal core material;

[0009] The metal core material constitutes the support core;

[0010] The polymer layer constitutes the filling part by melting.

[0011] Optionally, the metal core material constitutes the through structure based on the gap formed by knitting and / or coiling of the composite wire material.

[0012] Optionally, the composite wire material is configured to be knitted and / or coiled on a core, and is melted and formed into the composite fusion inner layer.

[0013] Optionally, the microcatheter is an integral variable diameter catheter, or the microcatheter includes a variable diameter section.

[0014] Optionally, the microcatheter includes a main section and an irregular section, and the cross-section of the composite welded inner layer at the irregular section is different from the cross-section of the composite welded inner layer at the main section.

[0015] Optionally, the outer layer is overlaid on the composite welded inner layer by reflow soldering.

[0016] To address the aforementioned technical problems, the present invention provides an interventional system comprising the microcatheter as described above.

[0017] In summary, in the microcatheter and interventional system provided by the present invention, the microcatheter includes: a composite fused inner layer and an outer layer; the composite fused inner layer includes a support core and a filling portion; the support core extends in a tubular shape along the axial direction of the microcatheter, and the support core has a permeable structure along the radial direction of the microcatheter; the filling portion covers the inner side of the support core and fills the permeable structure; the outer layer covers the outer side of the composite fused inner layer.

[0018] This configuration, through the addition of a composite welded inner layer, which covers the inside of the support core and incorporates a permeable structure, eliminates the need for winding or braiding the inner tube in existing technologies. This avoids the wrinkling problem inherent in the inner tube, simplifies the process, and improves the molding quality of the microcatheter. The microcatheter and interventional system provided by this invention are particularly suitable for irregularly shaped or variable-diameter microcatheters. Attached Figure Description

[0019] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:

[0020] Figure 1 This is a schematic cross-sectional view of a microcatheter involved in the present invention;

[0021] Figure 2 yes Figure 1 A schematic diagram showing the formation of wrinkles in the inner tube of the microcatheter.

[0022] Figure 3 This is a schematic cross-sectional view of the microcatheter according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the composite filament material according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a variable diameter microcatheter according to an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of an irregularly shaped microcatheter according to an embodiment of the present invention.

[0026] In the attached image:

[0027] 01-Inner tube; 02-Intermediate layer; 03-Outer layer;

[0028] 10-Composite fusion inner layer; 20-Outer layer; 30-Composite wire; 31-Metal core material; 32-Polymer layer; 41-Main body section; 42-Irregular shape section. Detailed Implementation

[0029] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0030] As used in this invention, the singular forms “a,” “an,” “one,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature; “one end” and “the other end,” and “proximal end” and “distal end” generally refer to two corresponding parts, which include not only endpoints. Furthermore, the terms "installed," "connected," and "attached," as used in this invention, and the term "set" on one element from another, should be interpreted broadly. They generally only indicate a connection, coupling, cooperation, or transmission relationship between the two elements, which can be direct or indirect through an intermediate element. They should not be construed as indicating or implying a spatial relationship between the two elements, meaning one element can be located inside, outside, above, below, or to one side of another element, unless otherwise explicitly stated. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Additionally, directional terms such as above, below, up, down, upward, downward, left, and right are used relative to exemplary embodiments as shown in the figures, with upward or upper directions pointing towards the top of the corresponding figure, and downward or lower directions pointing towards the bottom of the corresponding figure.

[0031] The purpose of this invention is to provide a microcatheter and interventional system to solve the problem that existing microcatheters are prone to inner tube wrinkles, leading to molding defects. The following description refers to the accompanying drawings.

[0032] Please refer to Figure 1 The diagram shows a cross-section of a microcatheter. The microcatheter comprises an inner tube 01, an intermediate layer 02, and an outer layer 03 arranged sequentially from the inside out. During production, the inner tube 01 is first nested within a liner, and then metal wire is braided or coiled around the inner tube 01 to form the intermediate layer 02. Finally, the outer layer 03 is formed by reflow soldering or similar processes around the intermediate layer 02. However, during the braiding or coiling of the intermediate layer 02, the tension generated by the metal wire acts on the inner tube 01 nested within the liner. This can easily damage the surface of the inner tube 01; furthermore, if the tension is too high, it can cause the inner tube 01 to slide on the liner, resulting in wrinkles. Figure 2 As shown. The wrinkles in the inner tube 01 not only affect the reflow soldering process of the outer layer 03, but also prevent the internal gaps of the intermediate layer 02 from being fully filled. This results in a loose bond between the three layers of the inner tube 01, intermediate layer 02, and outer layer 03, reducing the quality of the microcatheter, and also reducing the permeability of the guidewire within the microcatheter lumen.

[0033] Please refer to Figure 3 To overcome the problems existing in the above-mentioned microcatheters, this embodiment of the invention provides a microcatheter comprising: a composite welded inner layer 10 and an outer layer 20; the composite welded inner layer 10 includes a support core and a filling portion; the support core extends in a tubular shape along the axial direction of the microcatheter, and the support core has a permeable structure along the radial direction of the microcatheter; the filling portion covers the inner side of the support core and fills the permeable structure; the outer layer 20 covers the outer side of the composite welded inner layer 10.

[0034] The microcatheter provided in this embodiment is actually equivalent to having only two layers. The inner tube 01 is eliminated, which naturally eliminates the nesting process of the inner tube 01 and the braiding or spring winding process of the intermediate layer 02. On the one hand, it simplifies the process, and on the other hand, it avoids a series of problems caused by the wrinkles of the inner tube 01, thus improving the forming quality of the microcatheter.

[0035] However, the inventors discovered that the inner wall of the inner tube 01 in the prior art is relatively smooth, resulting in low internal friction and ensuring good passage of the guidewire within the microcatheter lumen. If the inner tube 01 is simply eliminated, and the intermediate layer 02 is constructed directly using braided or spring-wound metal wire, its inner wall is relatively rough, making it difficult for the guidewire to pass through smoothly. To eliminate the inner tube 01 while maintaining a smooth inner wall for easy guidewire passage, this embodiment incorporates a composite welded inner layer 10. The composite welded inner layer 10 includes a support core and a filling portion. The support core primarily provides torsional control and support for the entire microcatheter, while the filling portion, on one hand, covers the inner side of the support core, improving the smoothness of the microcatheter lumen wall; on the other hand, it fills the permeable structure of the support core, ensuring the integrity and sealing of the entire composite welded inner layer 10. This achieves the effect of eliminating the inner tube 01 while maintaining a smooth inner wall for easy guidewire passage.

[0036] Furthermore, the filling portion is melt-filled into the permeable structure and melt-coated onto the inner side of the support core. To ensure sufficient filling and coating, heating and melting are preferred. In some embodiments, the filling portion may be additionally attached to the outside of the support core before melting; after the support core is formed, the filling portion is heated to melt it, thus filling the permeable structure and coating the inner side of the support core. Optionally, the support core with the permeable structure can be formed, for example, by weaving and / or coiling metal wire, or by forming multiple permeable holes or grooves in a metal tube. The structure of the support core is not limited in this invention.

[0037] To simplify the process, please refer to... Figure 4 In one example, the composite welded inner layer 10 is formed by weaving and / or coiling a composite filament 30. Further, the composite filament 30 is configured to be woven and / or coiled on a core and melt-formed into the composite welded inner layer 10.

[0038] Optionally, the composite filament 30 includes a metal core 31 and a polymer layer 32 covering the metal core 31; the metal core 31 constitutes the support core; the polymer layer 32 forms the filling portion by melting. The metal core 31 can be a metal wire such as stainless steel wire, and the polymer layer 32 can be made of materials with good lubricity such as PTFE, PVC, Pebax, HDPE, or nylon. Preferably, the polymer layer 32 uniformly covers the metal core 31. Further, the gaps formed by the weaving and / or winding of the composite filament in the metal core 31 constitute the permeable structure.

[0039] The polymer layer 32 is thermoplastic after heating, and it can be melted by heat to produce fluidity, so that it can automatically fill the gaps (i.e., through structure) between the metal core 31 after the composite filament 30 is woven and / or coiled, and can also fill the gap between the metal core 31 and the lining core, thus automatically forming a relatively uniform and smooth inner wall layer.

[0040] Furthermore, after the composite welded inner layer 10 is prepared, and the filling part is cooled, the outer layer 20 can be wrapped around the composite welded inner layer 10 by reflow soldering, and then the liner can be removed, thus completing the preparation of the microcatheter.

[0041] The microcatheter provided in this embodiment is particularly suitable for variable diameter microcatheters (see Figure 5 (as shown) or irregularly shaped microcatheters (see) Figure 6 As shown in the figure, this can greatly simplify the processing technology of variable diameter microcatheters or irregularly shaped microcatheters.

[0042] Please refer to Figure 5 This invention illustrates a variable-diameter microcatheter. In traditional manufacturing processes, the inner tube 01 with a variable diameter is difficult to form, and it is difficult to fit it snugly against the liner during nesting, easily creating gaps between them. This leads to wrinkles during the weaving or coiling of the intermediate layer 02. However, the microcatheter provided in this embodiment, when applied to variable-diameter applications, can be directly woven and / or coiled onto the variable-diameter liner using composite filaments 30, ensuring a tight fit between the composite filaments 30 and the liner without deformation. The variable-diameter microcatheter is then prepared by heating and melting the polymer layer 32 of the composite filaments 30. It is understood that the variable-diameter microcatheter mentioned here can be a single variable-diameter conduit, or a microcatheter including variable-diameter sections, where a portion of the microcatheter is a variable-diameter conduit while the remaining portion can be a constant-diameter conduit.

[0043] Please refer to Figure 6 This illustrates an irregularly shaped microcatheter, comprising a main body segment 41 and an irregularly shaped segment 42, wherein the cross-section of the composite welded inner layer 10 at the irregularly shaped segment 42 differs from the cross-section of the composite welded inner layer 10 at the main body segment 41. For example, in... Figure 6 In the illustrated example, the irregular section 42 is mainly located at the tip (i.e., distal end) of the microcatheter, and its cross-section narrows along one radial side. Due to the variation in its cross-section, the irregular microcatheter is not easy to fit the liner when the inner tube 01 is nested, and it is also difficult to form using conventional manufacturing processes. Often, due to the tension variation of the intermediate layer 02, the inner tube 01 or the intermediate layer 02 shrinks or springs back after forming, resulting in the actual shape not matching the expected shape.

[0044] The microcatheter provided in this embodiment, when applied to irregularly shaped microcatheters, can be directly woven and / or coiled on a core with irregularly shaped segments using composite filaments 30, and then the polymer layer 32 of the composite filaments 30 can be heated and melted to complete the preparation of the irregularly shaped microcatheter. Furthermore, after the core is removed, since the filling part and the support core are fused together, they will not shrink or spring back, thus ensuring the shape of the irregularly shaped segment 42.

[0045] This invention also provides an interventional system comprising the microcatheter as described above. The structure and principles of other components of the interventional system can be found in existing technologies, and will not be elaborated upon here.

[0046] In summary, in the microcatheter and interventional system provided by this invention, the microcatheter includes: a composite welded inner layer and an outer layer; the composite welded inner layer includes a support core and a filling portion; the support core extends tubularly along the axial direction of the microcatheter, and the support core has a permeable structure along the radial direction of the microcatheter; the filling portion covers the inner side of the support core and fills the permeable structure; the outer layer covers the outer side of the composite welded inner layer. This configuration, through the setting of the composite welded inner layer, eliminates the step of winding or braiding the inner tube in the prior art by covering the inner side of the support core with the filling portion and filling the permeable structure, avoiding the wrinkling problem of the inner tube, simplifying the process, and improving the forming quality of the microcatheter. The microcatheter and interventional system provided by this invention are particularly suitable for irregularly shaped microcatheters or variable-diameter microcatheters.

[0047] It should be noted that the above embodiments can be combined with each other. The above description is only a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the present invention.

Claims

1. A microcatheter, characterized in that, include: The composite welded inner layer and outer layer; the composite welded inner layer includes a support core and a filler portion; the support core extends in a tubular shape along the axial direction of the microcatheter and has a permeable structure along the radial direction of the microcatheter; the filler portion covers the inner side of the support core and fills the permeable structure; the outer layer covers the outer side of the composite welded inner layer. The filling portion is filled into the permeable structure by melting and is also wrapped around the inner side of the support core by melting; the composite welded inner layer is formed by weaving and / or coiling composite filaments.

2. The microcatheter according to claim 1, characterized in that, The composite filament includes a metal core and a polymer layer covering the metal core. The metal core material constitutes the support core; The polymer layer is formed into the filling part by melting.

3. The microcatheter according to claim 2, characterized in that, The metal core material forms the permeable structure based on the gaps created by the weaving and / or coiling of the composite filament.

4. The microcatheter according to claim 1, characterized in that, The composite filament is configured to be woven and / or coiled on a core and melt-formed into the composite welded inner layer.

5. The microcatheter according to claim 1, characterized in that, The microcatheter is an integral variable diameter catheter, or the microcatheter includes a variable diameter section.

6. The microcatheter according to claim 1, characterized in that, The microcatheter includes a main section and an irregular section, and the cross-section of the composite welded inner layer at the irregular section is different from the cross-section of the composite welded inner layer at the main section.

7. The microcatheter according to claim 1, characterized in that, The outer layer is wrapped around the composite welded inner layer by reflow soldering.

8. An intervention system, characterized in that, Includes the microcatheter according to any one of claims 1 to 7.

Images