Medical multi-lumen shaft

Abstract

In a medical multi-lumen shaft, the present invention provides a design that is less susceptible to displacement or twisting of the sub-lumens due to external pressure loads applied during manufacturing. [Solution] A medical multi-lumen shaft 1 is provided with a sheath having a proximal end and a distal end, and between the proximal and distal ends there are main lumen sections 2, 5 and sub-lumen sections 3, 6 extending within the sheath, and the lumen section is covered with a braided layer 4. The main lumen section consists of a main lumen 2 with a shape that has a circular cross-section with a recess 8 formed by recessing inward from the outer circumference, and a main inner layer 5 that defines the cross-sectional shape thereof. The sub-lumen section consists of a sub-lumen 3 with a circular cross-section with an outer circumference, and a sub-inner layer 6 that defines the cross-sectional shape thereof. One or two sub-lumen sections fit into the recess of the main lumen section, and the sub-inner layer is in contact with the portion of the main inner layer that defines the recess.

Description

Technical Field

[0001] The present invention relates to a medical multi-lumen shaft including a main lumen and sub-lumens existing around it. In particular, the present invention relates to a medical multi-lumen shaft capable of suppressing the displacement of the position of the sub-lumen due to the resistance from a pulley or the like that runs during manufacturing, and the biting of the braided layer into the sub-lumen.

Background Art

[0002] Conventionally, various catheters have been used for vasodilation, angiography, and the like. In such a catheter, an operation performed at the proximal end (hand side, outside the body) is accurately transmitted to the distal end (tip side, inside the body), so that various treatment and diagnostic actions can be precisely performed in a narrow blood vessel or the like while avoiding damage to the body.

[0003] In a catheter, a shaft extending from the proximal end to the distal end is used, and a lumen (inner cavity) into which a wire operating instrument, a stent, a drug, or the like can be inserted and delivered is provided inside the shaft. Through this lumen, operations of a wire operating instrument and a guide wire, placement of a stent, delivery of a drug, and the like are performed.

[0004] In recent years, in order to realize these multiple actions with one catheter, many multi-lumen shafts having a plurality of lumens have been proposed (see Patent Documents 1 to 3). An example thereof is shown in FIG. 1. As shown in FIG. 1, a conventional multi-lumen shaft 1 generally has a plurality of lumens including a central main lumen 2 and small sub-lumens 3 existing around it, and has a configuration in which they are surrounded by a braided layer 4. For example, the main lumen is used for inserting a drug, an operating instrument, or the like, and the sub-lumen is used for inserting a wire or the like for catheter operation.

[0005] In the manufacturing of multi-lumen shafts, the intermediate product, in which the main lumen section containing the core material and the sub-lumen section are surrounded by a braided layer, is moved and wound up. At this time, as shown in Figure 2(a), it is necessary to use pulleys or the like. However, during the process of moving this intermediate product via pulleys P, as shown in Figures 2(b) and (c), the sub-inner layer 6 that forms the outer sub-lumen 3 sometimes experiences resistance from the groove surface of the pulley P, causing the sub-lumen section to shift position. Furthermore, in conventional multi-lumen shafts like the one shown in Figure 1, the structure is such that the sub-inner layer 6 that forms the circular cross-section sub-lumen 3 is arranged around the main inner layer 5 that forms the circular cross-section main lumen 2. When these are braided and fixed with a braided layer 4, the tightening force of the braided layer 4 is concentrated on the sub-inner layer 6 that forms the outer sub-lumen 3, and the braided layer 4 sometimes bites strongly into the sub-inner layer 6. As a result, it sometimes becomes difficult to pull the core material 11 out of the sub-lumen 3 in the later manufacturing process.

[0006] When catheters with such problems are used, the position of the sub-brum may be deviated from the design, or the insertion direction of the sub-brum may be twisted, making it difficult to accurately manipulate the operating instrument inserted into the sub-brum as intended. This could potentially prevent precise and safe treatment and diagnostic procedures in narrow blood vessels. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2008-92969 [Patent Document 2] Japanese Patent Publication No. 2018-143604 [Patent Document 3] Japanese Patent Publication No. 2020-18606 [Overview of the project] [Problems that the invention aims to solve]

[0008] The present invention was made to solve the problems of the prior art, and its purpose is to provide a medical multi-lumen shaft, which includes a main lumen and sub-lumens surrounding it, that ensures a sufficient usable cross-sectional area of ​​the main lumen, while also being less prone to displacement of the sub-lumens or core material extraction defects due to the braided layer biting into the sub-lumens, even when subjected to external pressure loads during manufacturing. [Means for solving the problem]

[0009] The inventors diligently studied means to suppress displacement of sub-lumines within the shaft and the intrusion of the braided layer into the sub-lumines in order to achieve the above objectives. As a result, they found that in a main lumen, which normally consists of an outer circumference with a circular cross-section, a recess is provided that is recessed inward from the outer circumference, and the sub-lumines are positioned to fit into this recess, thereby protecting the sub-lumines with the outer circumference of the main lumen. This prevents the sub-inner layer forming the outer sub-lumines from being subjected to concentrated pressure from the outside or concentrated tightening force from the braided layer. Consequently, they found that displacement of the sub-lumines from the originally intended design position and poor core material extraction due to the intrusion of the braided layer into the sub-inner layer forming the sub-lumines are substantially eliminated.

[0010] In other words, the present invention was completed based on the above findings and consists of the following configurations (1) to (10). (1) A medical multi-lumen shaft comprising a sheath having a proximal end and a distal end, wherein a plurality of independent lumen portions extending within the sheath between the proximal end and the distal end are present, and the lumen portions are covered with a braided layer, The lumen section comprises one main lumen section, The main lumen section It includes one or more independent sub-blumens surrounding it, The main lumen section has a shape in which one or more recesses are formed by recessing inward from the outer circumference of a substantially circular cross-section, The main lumen It consists of a main inner layer that defines the cross-sectional shape, The aforementioned sub-blumen portion has a sub-blumen with an outer circumference that has a substantially circular cross-section, The Sublumen It consists of a sub-inner layer that defines the cross-sectional shape, A medical multi-lumen shaft characterized in that one or two sub-lumen portions are fitted into the recess of the main lumen portion, and the sub-inner layer is in contact with the portion of the main inner layer that defines the recess. (2) The inner diameter of the circle that constitutes the outer periphery of the cross-section of the main lumen is the inner diameter of the circle that constitutes the outer periphery of the cross-section of the sub-lumen. of More than 3 times and The medical multi-lumen shaft according to (1), characterized in that both the main inner layer and the sub-inner layer are in contact with the braided layer. (3) The cross-section of the braided layer is approximately circular, The aforementioned approximately circular The medical multi-lumen shaft according to (1) or (2), characterized in that the center of the main lumen portion substantially coincides with the center of the circle that constitutes the outer periphery of the cross-section of the main lumen portion. (4) The recess in the main lumen section has a portion into which one of the sub-lumen sections fits, The aforementioned one goes inside A medical multi-lumen shaft according to (1) or (2), characterized in that, in a portion, the sub-inner layer is in contact with the main inner layer at the deepest part of the recess. (5) There is a portion in the recess of the main lumen portion into which two sub-lumen portions fit, The two mentioned above fit inside. In part 、2 individual The aforementioned The sub-inner layers of the sub-brume are in contact with each other. 、2 individual The aforementioned A medical multi-lumen shaft according to (1) or (2), characterized in that the sub-inner layer of the sub-lumen portion is in contact with the main inner layer located on both sides of the recess of the main lumen portion. (6) The medical multi-lumen shaft according to (1) or (2), characterized in that the recess is made in a symmetrical shape when viewed from a straight line connecting the deepest part of the recess of the main lumen section and the center of the circle that constitutes the outer circumference of the main lumen section. (7) The medical multi-lumen shaft according to (6), characterized in that the shape of the recess includes an arc 1 that includes the deepest part of the recess and two arcs 2 that are continuous with each end of the arc 1, the outer side of the bulging circle of the arc 1 is directed toward the center of the circle that constitutes the outer circumference of the main lumen, and the outer sides of the bulging circles of the two arcs 2 are directed toward the braided layer. (8) The medical multi-lumen shaft according to (1) or (2), characterized in that the number of recesses is 1 to 4. (9) The medical multi-lumen shaft according to (1) or (2), characterized in that the number of sub-lumen sections is 1 to 8. A medical catheter characterized by using a medical multi-lumen shaft as described in (10)(1) or (2). [Effects of the Invention]

[0011] The medical multi-lumen shaft of the present invention is configured such that a recess is provided in the main lumen, which has a circular cross-section formed by being recessed from the outer circumference, and a sub-lumen fits into the position of this recess. This allows for sufficient usable cross-sectional area of ​​the main lumen while significantly reducing the direct external pressure load on the sub-lumen. Furthermore, it prevents the sub-inner layer forming the sub-lumen from moving from its original design position due to resistance from pulleys and other components used during manufacturing, and prevents the braided layer from biting into the sub-inner layer forming the sub-lumen, resulting in defects in core material extraction. As a result, the positional accuracy of the sub-lumen in the shaft is improved, and manufacturing defects caused by the sub-lumen can be substantially eliminated. Therefore, the medical multi-lumen shaft of the present invention is extremely suitable for safely and accurately manipulating medical catheters. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a cross-sectional view of an example of a conventional multi-lumen shaft configuration. [Figure 2]FIG. 2 is a schematic diagram for explaining how the sub lumen of a conventional multi lumen shaft is strongly pressured by a pulley during conveyance. (a) is a schematic side view showing how an intermediate product of the shaft is conveyed by the pulley, (b) is a schematic front view showing how the intermediate product of the shaft is placed on the pulley and conveyed, and (c) is a schematic explanatory diagram obtained by enlarging the surrounded part of (b). [Figure 3] FIG. 3 is a cross-sectional view of an example of the configuration of the multi lumen shaft of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of an example of the configuration of the multi lumen shaft of the present invention when the number of sub lumens is one. [Figure 5] FIG. 5 is a cross-sectional view of three examples of the configuration of the multi lumen shaft of the present invention when the number of sub lumens is two. (a) shows the case where the interval between the centers of the sub lumens is 90° as seen from the center of the shaft, (b) shows the case where the interval between the centers of the sub lumens is 120° as seen from the center of the shaft, and (c) shows the case where the interval between the centers of the sub lumens is 180° as seen from the center of the shaft. [Figure 6] FIG. 6 is a cross-sectional view of two examples of the configuration of the multi lumen shaft of the present invention when the number of sub lumens is three. (a) shows the case where the interval between the centers of the sub lumens is 90° as seen from the center of the shaft, and (b) shows the case where the interval between the centers of the sub lumens is 120° as seen from the center of the shaft. [Figure 7] FIG. 7 is a cross-sectional view of three examples of the configuration of the multi lumen shaft of the present invention when the number of recesses in the main lumen part is four. (a) shows the case where one sub lumen part fits into each recess, (b) shows the case where one or two sub lumen parts fit into each recess, and (c) shows the case where two sub lumen parts fit into each recess. [Figure 8] FIG. 8 is a cross-sectional view of two examples of the shape of the recess in the multi lumen shaft of the present invention. (a) shows an example where the radius of curvature of the arc forming the recess is small, and (b) shows an example where the radius of curvature of the arc forming the recess is large. [Figure 9]Figure 9 is a schematic diagram illustrating a part of the process for manufacturing each lumen section in the manufacturing of the multi-lumen shaft of the present invention, where (a) shows the lumen section with the core material inserted, and (b) shows the state in which the core material is pulled from both ends in the lumen section of (a) and peeled off from the inner layer. [Modes for carrying out the invention]

[0013] Embodiments of the medical multi-lumen shaft of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments.

[0014] The medical multi-lumen shaft of the present invention has a large main lumen located in the center and smaller sub-lumens surrounding it, which serve as the internal lumen through which operating instruments, drugs, etc. are inserted. The main lumen typically has a circular outer cross-section, and a recess is formed in the outer circumference of the main lumen, extending toward approximately the center of the main lumen. The sub-lumens are positioned to fit into these recesses. Due to this characteristic configuration, even when subjected to resistance from pulleys or tightening forces from the braided layer during manufacturing, the sub-lumens are protected by the recess in the main lumen and receive almost no direct pressure. As a result, displacement of the outer sub-lumens from their designed positions and intrusion of the braided layer into the sub-inner layer forming the sub-lumens are less likely to occur, significantly improving the positional accuracy of the sub-lumens and substantially eliminating manufacturing defects caused by the sub-lumens. When the shapes of the main lumen and sub-lumens are referred to herein, they are basically based on their cross-sectional shapes.

[0015] Figure 3 is a schematic cross-sectional view of an example of the configuration of the multi-lumen shaft of the present invention. In Figure 3, 1 is the multi-lumen shaft, 2 is the main lumen, and 3 is the sub-lumen. The main lumen 2 has a cross-sectional shape with a recess 8 formed by the outer circumference of a circular cross-section inward. The sub-lumen 3 has a cross-sectional shape consisting of an outer circumference of a circular cross-section. 5 is the main inner layer defining the cross-sectional shape of the main lumen 2, and 6 is the sub-inner layer defining the cross-sectional shape of the sub-lumen 3. In the present invention, the main lumen 2 and the main inner layer 5 are collectively called the main lumen section, and the sub-lumen 3 and the sub-inner layer 6 are collectively called the sub-lumen section. 4 is a braided layer that contacts both the outside of the main inner layer 5 and the outside of the sub-inner layer 6, fixing the main lumen sections 2, 5 and the sub-lumen sections 3, 6 from the outside. The cross-section of the braided layer 4 is preferably approximately circular, and the center of the circle approximately coincides with the center of the circle that constitutes the outer periphery of the cross-section of the main lumen sections 2 and 5. 8 is a recess in the cross-section of the main lumen 2, which bulges toward the center of the main lumen 2. 10 is the outer layer 10 that covers the main lumen sections 2 and 5, the sub-lumen sections 3 and 6, and the braided layer 4.

[0016] The multi-lumen shaft of the present invention is configured to include, as an internal lumen, one main lumen section having one or more recesses formed by recessing from the outer circumference of a circular cross-section, and one or more independent sub-lumen sections with a circular cross-section that fit into the recesses of the main lumen section. The number of sub-lumen sections in one shaft is preferably 1 to 8, and more preferably 2 to 4, depending on the number of required functions. The number of recesses formed in one main lumen section is preferably 1 to 4, depending on the number of sub-lumen sections required. It is preferable that one or two sub-lumen sections are arranged in the recesses formed in the main lumen section so that one recess fits into one recess. In this case, it is preferable that the sub-inner layer 6 of the sub-lumen section is in contact with the portion of the main inner layer 5 that defines the cross-sectional shape of the recess 8. In Figure 3, one main lumen section 2,5 is located in the center of the shaft 1, and four recesses 8 of the main lumen section are provided at 90° intervals from the center of the shaft 1 (main lumen section), with the same shape and at equal distances in the radial direction. Then, one sub-blumen portion 3, 6 is positioned to fit into each of the recesses 8.

[0017] In the multi-lumen shaft of the present invention, it is preferable that the main lumen section and the sub-lumen section extend within a sheath (outer shell) having a proximal end (near end, outside the body) and a distal end (near end, outside the body), maintaining essentially the same cross-sectional shape and size from the proximal end to the distal end. The inner diameter of the circle constituting the outer periphery of the cross-section of the main lumen is preferably 3 times or more, more preferably 4 times or more, and more preferably 5 times or more, the inner diameter of the circle constituting the outer periphery of the cross-section of the sub-lumen, and there is no particular upper limit, but it is preferably 12 times or less. Furthermore, the inner diameter of the circle constituting the outer periphery of the cross-section of the main lumen is preferably 3 times or more, more preferably 4 times or more, and more preferably 5 times or more, the distance from the circle constituting the outer periphery of the cross-section of the main lumen to the deepest recess of the recess, and there is no particular upper limit, but it is preferably 12 times or less. By making the cross-sectional area of ​​the circular outer circumference, excluding the recess of the main lumen, larger, the usable insertion cross-sectional area of ​​the main lumen can be increased. However, if the deepest part of the recess of the main lumen is small, the inner diameter of the sub-lumen that can fit into the recess will be small.

[0018] In the multi-lumen shaft of the present invention, the shape of the recess in the main lumen section is not particularly limited as long as the sub-lumen section can stably fit into the recess. However, it is preferable that the recess is symmetrical, as shown in Figure 3, when viewed from a line connecting the deepest part of the recess (or the center of the deepest part if there is not a single deepest point) and the center of the circle that constitutes the outer circumference of the main lumen section. This is to improve the seating of the sub-lumen section in the recess of the main lumen section and to stabilize the position of the sub-lumen section. In order for the sub-lumen section with a circular cross-section to stably fit into the recess, the shape of the recess is preferably configured to include an arc 1 that includes the deepest part of the recess, and two arcs 2 that are continuous at both ends of arc 1, as shown in Figure 8. In this case, as shown in Figure 8, it is preferable that the outside of the bulging circle of arc 1 is directed toward the center of the circle that constitutes the outer circumference of the main lumen, and the outside of the bulging circles of the two arcs 2 at both ends are directed toward the braided layer. In Figure 8(a), arcs 1 and 2 have a smaller radius of curvature than arcs 1 and 2 in Figure 8(b). While a smaller radius of curvature in the arc, as in Figure 8(a), provides better protection for the sub-lumen from external pressure, it results in poor stability during transport, making the shaft prone to tipping and consequently twisting. On the other hand, a larger radius of curvature in the arc, as in Figure 8(b), makes the sub-lumen more susceptible to external pressure, but it tends to provide better stability for the main lumen and a larger, more usable insertion cross-sectional area within the main lumen.

[0019] Next, in the multi-lumen shaft of the present invention, when the number of recesses in the main lumen section is 1 to 3, cross-sectional views of an example configuration in which one sub-lumen section is fitted into each of the recesses are shown in Figures 4 to 6, and when the number of recesses in the main lumen section is 4, a cross-sectional view of an example configuration in which one or two sub-lumen sections are fitted into each of the recesses is shown in Figure 7. The reference numerals in Figures 4 to 7 basically refer to the same things as the reference numerals in Figure 3.

[0020] Figure 4 is a cross-sectional view of an example of a multi-lumen shaft in which both the number of sub-lumines in the shaft and the number of recesses in the main lumen section are one, with one sub-lumine fitting into the position of the one recess. In the multi-lumen shaft 1 of Figure 4, the main lumen sections 2 and 5 are provided with one recess 8 formed by recessing inward from the circular outer circumference, and one sub-lumine section 3 and 6 fit into the position of this recess 8. In that section, the sub-inner layer 6 is in contact with the main inner layer 5 at the deepest part of the recess 8. The braided layer 4 is then braided from the outside of the main lumen sections 2 and 5 into which the sub-lumine section 3 and 6 fit into the recess 8, fixing the main lumen section 2 and 5 and the sub-lumine section 3 and 6 in place. Furthermore, an outer layer 10 is provided to cover them. In the example shown in Figure 4, while maximizing the usable cross-sectional area of ​​the main lumen within the limited cross-sectional area of ​​the shaft, the pressure load from pulleys and other components that move during manufacturing, as well as the pressure load from the braided layer, are distributed to the large main lumen section without concentrating them in the small sub-lumen section. As a result, the sub-lumen section does not move under pressure during manufacturing, nor does it cause defects in the core material of the sub-lumen, effectively eliminating manufacturing defects caused by the sub-lumen section.

[0021] Figure 5 is a cross-sectional view of an example of a multi-lumen shaft in which both the number of sub-lumines in the shaft and the number of recesses in the main lumen section are two, with one sub-lumine fitting into each recess. Figure 5(a) shows a configuration where the distance between the centers of the circles forming the cross-section of the two sub-lumines is 90° when viewed from the center 9 of the shaft 1, (b) shows a 120° distance, and (c) shows a 180° distance. In the multi-lumen shaft 1 of Figure 5, the main lumen sections 2 and 5 are provided with two recesses 8 formed by recessing inward from the circular outer circumference, and one sub-lumine section 3 and 6 fits into each recess 8. In that section, the sub-inner layer 6 is in contact with the main inner layer 5 at the deepest part of the recess 8. The braided layer 4 is braided from the outside of the main lumen sections 2 and 5 into which the sub-lumines 3 and 6 fit into the recesses 8, fixing the main lumen sections 2 and 5 and the surrounding sub-lumines 3 and 6. Furthermore, an outer layer 10 is provided to cover them. In the example shown in Figure 5, while maximizing the usable cross-sectional area of ​​the main lumen within the limited cross-sectional area of ​​the shaft, the pressure load from pulleys and other components that move during manufacturing, as well as the pressure load from the braided layer, are distributed to the large main lumen section without concentrating them on the small sub-lumen section. As a result, the sub-lumen section does not move under pressure during manufacturing, nor does it cause defects in the core material of the sub-lumen, effectively eliminating manufacturing defects caused by the sub-lumen section.

[0022] Figure 6 is a cross-sectional view of an example of a multi-lumen shaft in which both the number of sub-lumines in the shaft and the number of recesses in the main lumen are three, with one sub-lumine fitting into each recess. Figure 6(a) shows a configuration where the distance between the centers of the circles forming the cross-section of the three sub-lumines is 90° when viewed from the center 9 of the shaft 1, and (b) shows a configuration where the distance is 120°. In the multi-lumen shaft 1 of Figure 6, the main lumen sections 2 and 5 are provided with three recesses 8 formed by recessing inward from the circular outer circumference, and one sub-lumine section 3 and 6 fits into each recess 8. In that section, the sub-inner layer 6 is in contact with the main inner layer 5 at the deepest part of the recess 8. The braided layer 4 is braided from the outside of the main lumen sections 2 and 5 into which the sub-lumines 3 and 6 fit into the recesses 8, fixing the main lumen sections 2 and 5 and the surrounding sub-lumines 3 and 6. Furthermore, an outer layer 10 is provided to cover them. In the example shown in Figure 6, while maximizing the usable cross-sectional area of ​​the main lumen within the limited cross-sectional area of ​​the shaft, the pressure load from pulleys and other components that move during manufacturing, as well as the pressure load from the braided layer, are distributed to the large main lumen section without concentrating them in the small sub-lumen section. As a result, the sub-lumen section does not move under pressure during manufacturing, nor does it cause defects in the core material of the sub-lumen, effectively eliminating manufacturing defects caused by the sub-lumen section.

[0023] Figure 7 is a cross-sectional view of an example of a multi-lumen shaft in which both the number of sub-lumines in the shaft and the number of recesses in the main lumen section are four, with one or two sub-lumines positioned in each recess. Figure 7(a) shows a configuration where one sub-lumine is positioned in each of the four recesses, (b) shows a configuration where one sub-lumine is positioned in three of the four recesses and two sub-lumines are positioned in the remaining one recess, and (c) shows a configuration where two sub-lumines are positioned in each of the four recesses. In the multi-lumen shaft 1 of Figure 7, the main lumen sections 2 and 5 are provided with four recesses 8 formed by recessing inward from the circular outer circumference, with one or two sub-lumines 3 and 6 positioned in each recess 8. In the section where one sub-blumen section 3,6 is inserted, the sub-inner layer 6 is in contact with the main inner layer 5 at the deepest part of the recess 8. In the section where two sub-blumen sections 3,6 are inserted, the sub-inner layer 6 is in contact with the main inner layer 5 on both sides of the recess 8 of the main lumen section 2,5. The braided layer 4 is then braided from the outside of the main lumen section 2,5 into which the sub-blumen sections 3,6 are inserted into the recess 8, fixing the main lumen section 2,5 and the surrounding sub-blumen sections 3,6. Furthermore, an outer layer 10 is provided to cover them. In the example in Figure 7, numerous sub-blumen sections are provided while maximizing the usable cross-sectional area of ​​the main lumen within the limited cross-sectional area of ​​the shaft. This allows pressure loads from pulleys and other components running during manufacturing, as well as pressure loads from the braided layer, to be distributed to the large main lumen section without concentrating them in the small sub-blumen sections. As a result, the sub-blumen portion does not shift under pressure during manufacturing, nor does it cause defects in the core material of the sub-blumen, effectively eliminating manufacturing defects caused by the sub-blumen portion.

[0024] The main inner layer, sub-inner layer, braided layer, and outer layer covering them that constitute the multi-lumen shaft of the present invention can be formed using materials conventionally used in this field. In addition to these, an intermediate layer such as a metal coil layer can be provided on the outside of the main inner layer or sub-inner layer to ensure kink resistance, bendability, and rigidity. This material can also be formed using materials conventionally used in this field. The material for the main inner layer or sub-inner layer is required to have properties such as chemical resistance, lubricity, heat resistance during part processing, and friction resistance during insertion, and thermoplastic resins are generally used accordingly. For example, fluororesins such as perfluoroalkoxy fluororesins (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and ethylene-tetrafluoroethylene copolymer (ETFE); polyolefins such as polypropylene, polyethylene, and ethylene acetate copolymer; polyamides; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyvinyl chloride, polyurethane polystyrene, and polyimide; and various elastomers such as fluorinated elastomers, polyamide elastomers, polyester elastomers, and polystyrene elastomers, as well as modified versions thereof, polymer alloys, and mixtures can be used. Among these, fluororesins are preferred because they suitably satisfy the above-mentioned properties.

[0025] The material required for the braided layer must provide sufficient reinforcement, and metal wires are commonly used. For example, various metallic materials such as stainless steel, copper, tungsten, nickel, titanium, piano wire, superelastic alloys such as Ni-Ti alloy, Ni-Ti-Co alloy, Ni-Al alloy, Cu-Zn alloy, and Cu-Zn-X alloy (X=Be, Si, Sn, Al, Ga), and amorphous alloys can be used. Furthermore, resin materials can also be used, such as polyesters like polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polymethylene terephthalate (PPT); polyolefins like polyethylene and polypropylene; rigid polyvinyl chloride; polyamide; polyimide; polystyrene; thermoplastic polyurethane; polycarbonate; ABS resin; acrylic resin; polymethyl methacrylate (PMMA); polyacetal (PA); polyarylate; polyoxymethylene (POM); high-tensile polyvinyl alcohol; fluororesin; polyvinylidene fluoride (PVdF); polytetrafluoroethylene; ethylene vinyl acetate saponify (EVOH); polysulfone; polyethersulfone; polyetherketone; polyphenylene oxide; polyphenylene sulfide; and aromatic polyaramid. Among these, stainless steel is preferred in terms of X-ray visibility, processability, and cost-effectiveness.

[0026] The outer layer material requires properties such as surface smoothness and flexibility to minimize resistance during insertion into blood vessels, and thermoplastic resins are generally used accordingly. For example, polyamides such as nylon 6, nylon 11, nylon 12, nylon 64, nylon 66, nylon 610, nylon 612, nylon 6T, nylon 6I, nylon 9T, and nylon 5MT; polyolefins such as polypropylene, polyethylene, and ethylene acetate copolymer; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyvinyl chloride, polyurethane polystyrene, and polyimide; as well as various elastomers such as fluorine-based elastomers, polyamide elastomers, polyester elastomers, and polystyrene elastomers, modified versions thereof, polymer alloys, and mixtures can be used. Among these, polyamide resins are preferred because they suitably satisfy the above properties.

[0027] The manufacturing method for the multi-lumen shaft of the present invention is not particularly limited, and conventionally known methods can be used as appropriate. For example, the following steps (i) to (v) are preferably employed as the manufacturing method: (i) A core material having the same cross-sectional shape as the main lumen is prepared, and the resin of the main inner layer is coated onto this core material to create a core-filled main lumen section. The core material used has 20-50% elasticity, and metal wires or resin wires can be used. (ii) A core material having the same cross-sectional shape as the sub-lumen is prepared, and the resin of the sub-inner layer is coated onto this core material to create a core-filled sub-lumen section. The core material can be made of the same material as the core material of the main lumen. (iii) The core-filled sub-lumen section formed in (ii) is placed into the recess of the core-filled main lumen section formed in (i), and the surrounding area is braided with metal wire to form a braided layer. (iv) The outer layer is formed by coating the braided layer with resin by extrusion molding. At this time, the resin constituting the outer layer is made to fit seamlessly between the braided layer and each inner layer. (v) As shown in Figures 9(a) and (b), the core material is peeled from the inner layer by pulling both ends of the elastic core material to reduce its diameter, and the core material is pulled out from the structure formed in (iv) in the same manner as pulling out the core material, thereby completing the lumens of the main lumen and sub-lumens and completing the multi-lumen shaft. In the multi-lumen shaft of the present invention, since the sub-lumens are positioned in the recesses of the main lumen, even if the above manufacturing method is adopted, the braided layer is less likely to bite into the sub-inner layers that form the sub-lumens, and the occurrence of core material extraction defects can be suppressed. [Examples]

[0028] The following examples illustrate the effects of the multi-lumen shaft of the present invention, but the present invention is not limited to these examples.

[0029] Example 1 An intermediate product of a multi-lumen shaft with the cross-sectional shape shown in Figure 3 was manufactured according to the processes (i) to (iii) described above. The inner diameter of the main lumen (assuming there are no recesses) was 2.5 mm, and the inner diameter of the sub-lumen was 0.3 mm. Furthermore, fluororesin was used for the main inner layer and sub-inner layer, nylon 6 was used for the outer layer, and stainless steel wire was used for the braided layer.

[0030] Comparative Example 1 An intermediate product of a multi-lumen shaft with the cross-sectional shape shown in Figure 1 was fabricated using the same materials and methods as in Example 1. The inner diameter of the main lumen was 2.5 mm, and the inner diameter of the sub-lumen was 0.3 mm.

[0031] Evaluation of Sublumen's positional accuracy Intermediate products of the multi-lumen shafts obtained in Example 1 and Comparative Example 1 were passed four times through a pulley as shown in Figure 2(a), and then subjected to the above steps (iv) to (v). Ten samples were obtained by cutting them into 1m lengths. Electron microscope images were taken of the cross-sections of the ends of these samples, and the angle between the centers of adjacent sub-lumens as viewed from the center of the main lumen (shaft) that deviated the most from the design of 90 degrees was extracted, and the angle deviation was measured. The measurement results are shown as the average of the measured values ​​of the ten samples.

[0032] [Table 1]

[0033] As can be seen from the results in Table 1, Example 1, which corresponds to the multi-lumen shaft of the present invention, has extremely high positional accuracy of the sub-lumen compared to Comparative Example 1, which corresponds to a conventional multi-lumen shaft. Medical catheters using the multi-lumen shaft of the present invention can safely and accurately manipulate instruments and the like inserted through the sub-lumen. [Industrial applicability]

[0034] The multi-lumen shaft of the present invention offers excellent positional accuracy in the small sub-lumens provided around the main lumen shaft, allowing for safe and precise manipulation of operating instruments inserted through the sub-lumens, making it suitable for use in medical catheters. [Explanation of symbols]

[0035] 1 Multi-lumen shaft 2 main lumens 3 Sub-Blumen 4 braided layers 5 Main Inner Layer 6. Sub-inner layer 8 recesses 9 center 10 outer layer 11 Core material P Pulley

Claims

1. A medical multi-lumen shaft comprising a sheath having a proximal end and a distal end, wherein a plurality of independent lumen sections extending within the sheath between the proximal end and the distal end are present, and the lumen sections are covered with a braided layer, The lumen section includes one main lumen section and one or more independent sub-lumen sections surrounding the main lumen section. The main lumen section comprises a main lumen having a shape in which one or more recesses are formed by recessing inward from the outer circumference of a substantially circular cross-section, and a main inner layer that defines the cross-sectional shape of the main lumen. The sub-blumen portion consists of a sub-blumen with an outer peripheral shape having a substantially circular cross-section, and a sub-inner layer that defines the cross-sectional shape of the sub-blumen. A medical multi-lumen shaft characterized in that one or two sub-lumen portions are fitted into the recess of the main lumen portion, and the sub-inner layer is in contact with the portion of the main inner layer that defines the recess.

2. The medical multi-lumen shaft according to claim 1, characterized in that the inner diameter of the circle constituting the outer periphery of the cross-section of the main lumen is three times or more the inner diameter of the circle constituting the outer periphery of the cross-section of the sub-lumen, and both the main inner layer and the sub-inner layer are in contact with the braided layer.

3. The medical multi-lumen shaft according to claim 1 or 2, characterized in that the cross-section of the braided layer is substantially circular, and the center of the substantially circular area substantially coincides with the center of the circle that constitutes the outer periphery of the cross-section of the main lumen section.

4. The medical multi-lumen shaft according to claim 1 or 2, characterized in that there is a portion in the recess of the main lumen portion into which one sub-lumen portion fits, and in the portion into which one sub-lumen portion fits, the sub-inner layer is in contact with the main inner layer at the deepest part of the recess.

5. The medical multi-lumen shaft according to claim 1 or 2, characterized in that there is a portion into which two sub-lumen portions fit in the recess of the main lumen portion, the sub-inner layers of the two sub-lumen portions are in contact with each other in the portion into which the two sub-lumen portions fit, and the sub-inner layers of the two sub-lumen portions are in contact with the main inner layer on both sides of the recess of the main lumen portion.

6. The medical multi-lumen shaft according to claim 1 or 2, characterized in that the recess is made symmetrically shaped when viewed from a straight line connecting the deepest part of the recess in the main lumen section and the center of the circle that constitutes the outer circumference of the main lumen section.

7. The medical multi-lumen shaft according to claim 6, characterized in that the shape of the recess includes an arc 1 that includes the deepest part of the recess, and two arcs 2 that are continuous with each end of the arc 1, the outer side of the bulging circle of the arc 1 is directed toward the center of the circle that constitutes the outer circumference of the main lumen, and the outer sides of the bulging circles of the two arcs 2 are each directed toward the braided layer.

8. The medical multi-lumen shaft according to claim 1 or 2, characterized in that the number of recesses is 1 to 4.

9. The medical multi-lumen shaft according to claim 1 or 2, characterized in that the number of sub-lumen sections is 1 to 8.

10. A medical catheter characterized by using a medical multi-lumen shaft as described in claim 1 or 2.

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