Catheter

Abstract

Provided is a catheter (1) having a longitudinal direction (x) and comprising a catheter body (2) that has a first lumen (11) and a second lumen (21), which has a proximal end (21A) located closer to the distal side than a proximal end (11A) of the first lumen (11) and is enclosed in the first lumen (11), the catheter body (2) having a twisted portion (40) twisted clockwise about the axial line in the longitudinal direction (x) in a section where the second lumen (21) is present in the longitudinal direction (x).

Description

Catheter

[0001] The present disclosure relates to a catheter.

[0002] Catheters that can be inserted into body lumens such as blood vessels and digestive tracts are used for examining and treating lesions in the human body. In order to make such catheters easily conform to the shape of body lumens, as disclosed in Patent Document 1, a bending habit is sometimes imparted to the portion inserted into the body.

[0003] Japanese Unexamined Patent Publication No. 2019-055041

[0004] Providing a catheter whose distal end is bent in a desired direction is extremely useful for meeting diverse needs in the medical field. In particular, for catheters, the twisted shape of the distal end is directly linked to operability and conformability to body lumens. Accordingly, an object of the present disclosure is to provide a catheter that can be smoothly delivered to a lesion by easily conforming to the shape of a body lumen.

[0005] A catheter according to an embodiment that can solve the above problems is as follows. [1] A catheter having a longitudinal direction, comprising: a catheter body having a first lumen, and a second lumen whose proximal end is located more distally than the proximal end of the first lumen and is enclosed in the first lumen, wherein the catheter body has a twisted portion twisted clockwise around the longitudinal axis in a section of the longitudinal direction where the second lumen is present.

[0006] Furthermore, the catheter according to the embodiment is preferably any of the following [2] to [9]. [2] The catheter according to [1], wherein when the catheter is placed on a horizontal surface, only a part of the catheter body in the longitudinal direction is in contact with the horizontal surface. [3] The catheter according to [2], wherein when the catheter is placed on a horizontal surface, the distal end of the catheter body is floating above the horizontal surface, and the remaining part of the catheter body in the longitudinal direction is in contact with the horizontal surface. [4] The catheter according to [2], wherein when the catheter is placed on a horizontal surface, the middle part of the catheter body in the longitudinal direction is floating above the horizontal surface, and the distal part of the catheter body and the proximal part of the catheter body are in contact with the horizontal surface. [5] The catheter according to [1] or [2], wherein when the catheter is placed on a horizontal surface, at the position of the proximal end of the second lumen, the second lumen is located vertically lower than the first lumen. [6] The catheter according to [1] or [2], wherein when the catheter is placed on a horizontal surface, the second lumen is located vertically above the first lumen at the position of the proximal end of the second lumen. [7] The catheter according to any one of [1] to [6], wherein the twisted portion is located within 30 cm from the distal end of the catheter body toward the proximal end. [8] The catheter according to any one of [1] to [7], wherein a balloon is disposed at the distal end of the catheter body, and the first lumen is in communication with the inside of the balloon. [9] The catheter according to any one of [1] to [8], which has a wire inserted into the second lumen from the distal end side of the catheter.

[0007] The presence of a twisted section in the catheter allows it to conform more easily to the shape of the internal lumen without the user having to twist it at the proximal end, thus enabling smoother delivery of the catheter to the lesion.

[0008] Figure 1 is a plan view of a catheter according to an embodiment of the present disclosure. Figure 2 is a schematic diagram of the catheter body of Figure 1 viewed from the side. Figure 3 is a cross-sectional view of the catheter of Figure 1 along its longitudinal direction, showing the balloon in a folded state and the curved portion extended along the longitudinal direction of the catheter. Figure 4 is an end view of the IV-IV section of the catheter of Figure 3. Figure 5 is an end view of the V-V section of the catheter of Figure 3. Figure 6 is a cross-sectional view showing the balloon of the catheter of Figure 3 in an inflated state, with the curved portion extended along the longitudinal direction of the catheter. Figure 7 is a schematic diagram showing a modified example of the catheter body of Figure 2. Figure 8 is a cross-sectional view showing a modified example of the catheter of Figure 5.

[0009] The contents of this disclosure will be described in more detail below based on the embodiments described below. However, the contents of this disclosure are not limited by the embodiments described below, and it is certainly possible to implement the disclosure with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of this disclosure. In addition, hatching and component reference numerals may be omitted in the drawings for convenience, in which case refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to helping to understand the features of this disclosure.

[0010] The catheter according to this embodiment is a catheter having a longitudinal direction, and has a catheter body having a first lumen and a second lumen whose proximal end is located distal to the proximal end of the first lumen and is enclosed within the first lumen, and the catheter body has a twisted portion in the longitudinal direction in the section where the second lumen is located, which is twisted clockwise around the longitudinal axis. With this catheter, the catheter can easily follow the three-dimensional shape of the body lumen without the user having to twist it at the proximal end, so that the catheter can be smoothly delivered to the lesion.

[0011] A catheter according to an embodiment will be described with reference to Figures 1 to 8. Figure 1 is a plan view of a catheter according to an embodiment of the present disclosure. Figure 2 is a schematic diagram of the catheter body of Figure 1 viewed from the side. Figure 3 is a cross-sectional view of the catheter of Figure 1 along the longitudinal direction, showing the balloon in a folded state and the curved portion extended along the longitudinal direction of the catheter. Figure 4 is an end view of the IV-IV section of the catheter of Figure 3. Figure 5 is an end view of the V-V section of the catheter of Figure 3. Figure 6 is a cross-sectional view showing the balloon of the catheter of Figure 3 in an inflated state, showing the curved portion extended along the longitudinal direction of the catheter. Figure 7 is a schematic diagram showing a modified example of the catheter body of Figure 2. Figure 8 is a cross-sectional view showing a modified example of the catheter of Figure 5. Note that in Figures 2 and 7, the structure of the catheter body is simplified in order to facilitate understanding of the structure of the twisted portion. The catheter 1 has a catheter body 2 having a first lumen 11 and a second lumen 21.

[0012] Catheter 1 is inserted into a body cavity such as a patient's blood vessels, digestive tract, or airway and used for treatment or examination. Examples of catheter 1 include balloon catheters. Preferably, the catheter is a so-called rapid exchange type balloon catheter.

[0013] An example of how to use catheter 1 is described below. Catheter 1 can be delivered to the lesion by inserting the catheter body 2 into the lumen of a guiding catheter that has been inserted into the body beforehand, and then moving the catheter body 2 distally. Insert the guiding catheter into the body and insert the guidewire from the proximal side of the guiding catheter. Then, insert the guidewire into the second lumen 21 and insert catheter 1 into the guiding catheter along the second lumen 21. Next, extend catheter 1 from the distal end of the guiding catheter. If catheter 1 is a balloon catheter, the balloon can be inflated by introducing fluid into the first lumen 11 of catheter 1. This allows for treatment and other procedures to be performed on the lesion.

[0014] As can be seen from Figure 1, the catheter 1 has a longitudinal direction x, and as can be seen from Figures 1, 3, 4, and 5, the catheter 1 preferably also has a radial direction y and a circumferential direction z. The longitudinal direction x can also be called the longitudinal axis direction. The catheter 1 preferably has a proximal end 3 and a distal end 4 in the longitudinal direction x. The proximal side of the catheter 1 refers to the direction toward the user or operator's proximal side with respect to the longitudinal direction x of the catheter, and the distal side refers to the opposite direction from the proximal side, i.e., the direction toward the target of treatment. The radial direction y of the catheter 1 refers to the radial direction of the catheter 1, and in the radial direction y, inward refers to the direction toward the longitudinal axis center of the catheter 1, and outward refers to the direction extending radially from the longitudinal axis center on the opposite side from inward. The circumferential direction z of the catheter 1 refers to the direction around the longitudinal axis. Hereinafter, in the longitudinal direction x of the catheter 1, when the length of each component is divided into two equal parts, the proximal side may be referred to as the proximal part, and the distal side as the distal part.

[0015] The catheter body 2 includes the portion of the catheter 1 that is inserted into the body. Preferably, the catheter body 2 is a tubular structure having at least two lumens. The catheter body 2 may be a portion of the catheter 1 other than the handle 60. Although not shown, the catheter body 2 may be provided with strain relief to prevent kinking of the proximal portion of the catheter body 2.

[0016] The catheter body 2 can be a resin tube; a metal tube; a hollow body formed by arranging wires in a predetermined pattern; a hollow body with at least one of its inner or outer surfaces coated with resin; or a combination thereof, for example, a combination of these connected in the longitudinal direction x. The resin tube can be manufactured, for example, by extrusion molding. Examples of hollow bodies with wires arranged in a predetermined pattern include cylindrical bodies having a mesh structure by simply crossing or weaving wires, and coils in which wires are wound. The wires may be one or more single wires, or one or more stranded wires. The type of mesh structure is not particularly limited, nor are the number of turns or density of the coils. The mesh structure or coil may be formed at a constant density over the entire longitudinal direction x of the catheter body 2, or it may be formed so that the density differs depending on the position in the longitudinal direction x.

[0017] The material constituting the catheter body 2 is preferably resin, metal, or a combination of resin and metal. Using resin makes it easier to impart flexibility and elasticity to the shaft. Using metal improves the ease of insertion of the catheter 1 into the body lumen.

[0018] Examples of resins that make up the catheter body 2 include polyamide resins such as polyamide, polyamide elastomer, and polyether polyamide; polyester resins such as polyethylene terephthalate and polyester elastomer; polyurethane resins such as polyurethane and polyurethane elastomer; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; fluorine resins such as PTFE, PFA, and ETFE; aromatic polyether ketone resins such as polyether ether ketone; polyphenylene sulfide resin; polystyrene resin; vinyl chloride resin; silicone resin; natural rubber; synthetic rubber; and polyimide resin. These may be used individually or in combination of two or more. Examples of polyamides include nylon 12 and nylon 11. Examples of polyamide elastomers include polyether ester amide elastomer and polyamide ether elastomer.

[0019] Examples of metals that make up the catheter body 2 include stainless steel such as SUS304 and SUS316, carbon steel, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, Ni-Ti alloy, and Co-Cr alloy. These may be used individually or in combination of two or more.

[0020] The catheter body 2 may have a single-layer structure or a multi-layer structure. If the catheter body 2 has a multi-layer structure, for example, a reinforcing material such as a wire made of metal such as stainless steel, carbon steel, or nickel-titanium alloy can be provided as an intermediate layer of the resin tube that constitutes the catheter body 2.

[0021] The length of the catheter body 2 in the longitudinal direction x is several to tens of times longer than the length of the handle 60 in the same direction, for example, about 500 mm to 1500 mm. The outer diameter of the catheter body 2 should be, for example, about 0.6 mm to 5.0 mm.

[0022] As shown in Figures 1, 3, and 4, the catheter body 2 has a first lumen 11 and a second lumen 21 whose proximal end 21A is located distal to the proximal end 11A of the first lumen 11 and which is enclosed within the first lumen 11.

[0023] As shown in Figure 3, it is preferable that the distal end 21B of the second lumen 21 is located distal to the distal end 11B of the first lumen 11. Although not shown, the distal end 21B of the second lumen 21 may be located proximal to the distal end 11B of the first lumen 11. As shown in Figure 1, the first lumen 11 may extend to the proximal end 3 of the catheter body 2.

[0024] As shown in Figure 3, the catheter body 2 may have a first inner surface 12 that defines the first lumen 11 and a second inner surface 22 that defines the second lumen 21.

[0025] The first lumen 11 is preferably extended in the longitudinal direction x. The second lumen 21 is preferably extended in the longitudinal direction x.

[0026] The second lumen 21 is preferably shorter in length x in the longitudinal direction than the first lumen 11.

[0027] It is preferable that the first lumen 11 does not move in the longitudinal direction x relative to the second lumen 21. The first lumen 11 may or may not move in the radial direction y relative to the second lumen 21.

[0028] The first lumen 11 is preferably a so-called over-the-wire type lumen. The second lumen 21 is preferably a so-called rapid-exchange type lumen.

[0029] As shown in Figure 3, a balloon 50 is positioned at the distal end of the catheter body 2, and it is preferable that the first lumen 11 communicates with the inside of the balloon 50. That is, it is preferable that the first lumen 11 is a flow path for the balloon expansion fluid. It is preferable that the second lumen 21 is an insertion passage for a guide wire that guides the advancement of the catheter body 2.

[0030] As shown in Figures 3 to 5, the catheter body 2 may have a first cylindrical portion 10 having a first lumen 11 and a second cylindrical portion 20 having a second lumen 21. Preferably, the first cylindrical portion 10 has a first inner circumferential surface 12 and the second cylindrical portion 20 has a second inner circumferential surface 22.

[0031] The first cylindrical portion 10 and the second cylindrical portion 20 may or may not be fixed to each other. Preferably, the outer surfaces of the first cylindrical portion 10 and the outer surfaces of the second cylindrical portion 20 are fixed directly or indirectly in the radial direction y. This makes it difficult for the second cylindrical portion 20 to twist or bend. Examples of fixing methods include welding and bonding. In Figures 3 and 5, the outer surface of the first cylindrical portion 10 is fixed to the outer surface of the second cylindrical portion 20 via a connecting tube 57. The connecting tube 57 is preferably, for example, a resin tube, but the structure and constituent materials of the connecting tube 57 can be found in the description of the structure and constituent materials of the catheter body 2.

[0032] As shown in Figure 3, it is preferable that the first cylindrical portion 10 has a distal opening 10G that communicates with the first lumen 11. It is preferable that the second cylindrical portion 20 has a distal opening 20G that communicates with the second lumen 21. The distal opening 20G can be used as the entrance and exit for the guide wire. It is preferable that the second cylindrical portion 20 has a proximal opening 20F that communicates with the second lumen 21. The proximal opening 20F can be used as the entrance and exit for the guide wire.

[0033] The structure of the first cylindrical portion 10 and / or the second cylindrical portion 20 can be described by referring to the description of the structure of the catheter body 2, but it is preferable that both the first cylindrical portion 10 and the second cylindrical portion 20 are made of resin tubing. The constituent materials of the first cylindrical portion 10 and / or the second cylindrical portion 20 can be described by referring to the description of the constituent materials of the catheter body 2. The first cylindrical portion 10 and the second cylindrical portion 20 may be made of the same material or of different materials.

[0034] The first cylindrical portion 10 and the second cylindrical portion 20 each preferably have one or more layers extending in the longitudinal direction x, and more preferably have multiple layers. The multiple layers preferably have an inner layer and an outer layer that encloses at least a part of the inner layer. The multiple layers may further have an intermediate layer located between the inner layer and the outer layer. The number of intermediate layers is not limited to one, but may be two or more. It is preferable that each of the multiple layers contains a different material from the adjacent layer.

[0035] The intermediate layer preferably contains a different material from the inner or outer layer, but it may also contain the same material as the inner or outer layer.

[0036] It is preferable that the inner layer, intermediate layer, and outer layer are fixed to the adjacent layer. This makes it less likely for each layer to twist or warp. Examples of fixing methods include welding and bonding. Although not shown in the figures, a reinforcing member may be placed as the intermediate layer.

[0037] In catheter 1, it is preferable that the first lumen 11 and the second lumen 21 are aligned radially y in at least a portion of the longitudinal direction x of the catheter body 2. More specifically, it is preferable that the first lumen 11 and the second lumen 21 are aligned radially as shown in Figure 5 at the most proximal position 2M (see Figure 3) where the first inner surface 12 and the second inner surface 22 are present around their entire circumference.

[0038] As shown in Figures 3 and 4, in the catheter body 2, it is preferable that the first lumen 11 is enclosed within the second lumen 21 at the most distal position 2N among the locations where the first inner surface 12 and the second inner surface 22 are present around the entire circumference.

[0039] As shown in Figure 3, the catheter body 2 has a distal shaft 45 and a proximal shaft 46, with a balloon 50 positioned at the distal end of the distal shaft 45. The distal shaft 45 may be composed of a first cylindrical portion 10 and a second cylindrical portion 20. Thus, the catheter body 2 may be a balloon catheter. The balloon catheter may be a balloon catheter for stent delivery. In that case, a stent may be mounted on the deflated balloon of the balloon catheter.

[0040] As shown in Figure 3, at position 2N, the second cylindrical portion 20 is positioned in the first lumen 11 of the first cylindrical portion 10. The second lumen 21 of the second cylindrical portion 20 can function as an insertion passage for a guidewire that guides the advancement of the catheter body 2. The space between the first cylindrical portion 10 and the second cylindrical portion 20 can function as a flow path for the balloon expansion fluid. When the catheter body 2 has a first cylindrical portion 10 and a second cylindrical portion 20, the second cylindrical portion 20 can extend from the distal end of the first cylindrical portion 10 and penetrate distal to the balloon 50, with the distal end of the balloon 50 joined to the second cylindrical portion 20 and the proximal end of the balloon 50 joined to the first cylindrical portion 10.

[0041] The first cylindrical portion 10 may constitute the proximal shaft 46. That is, the distal shaft 45 and the proximal shaft 46 may be made of the same material. On the other hand, the distal shaft 45 and the proximal shaft 46 may be made of different materials. If the distal shaft 45 and the proximal shaft 46 are made of different materials, the proximal shaft 46 may be made of resin or metal.

[0042] The balloon 50 has a longitudinal direction and a radial direction. The radial direction of the balloon 50 is the direction perpendicular to the longitudinal direction and means the direction extending radially from the center of the balloon 50. The balloon 50 also has a circumferential direction, which is the direction along the outer circumference of the expanded balloon 50 in a cross section perpendicular to the longitudinal direction of the balloon 50. In this document, the longitudinal, radial, and circumferential directions of the balloon 50 are described as coinciding with the longitudinal direction x, radial direction y, and circumferential direction z of the catheter body, but these directions may be different from each other.

[0043] As shown in Figure 3, it is preferable that the balloon 50 has a straight tube section 51, a distal tapered section 52 located distal to the straight tube section 51, and a proximal tapered section 53 located proximal to the straight tube section 51, in the longitudinal direction. The straight tube section 51 is formed in a substantially cylindrical shape extending in the longitudinal direction and has the largest radial length (outer diameter) in the balloon 50. The distal tapered section 52 is connected to the distal end of the straight tube section 51. The distal tapered section 52 is formed such that its outer diameter decreases as it moves distally away from the straight tube section 51. The proximal tapered section 53 is connected to the proximal end of the straight tube section 51. The proximal tapered section 53 is formed such that its outer diameter decreases as it moves proximal away from the straight tube section 51. Preferably, the balloon 50 further includes a distal sleeve portion 54 located distal to the distal tapered portion 52 and a proximal sleeve portion 55 located proximal to the proximal tapered portion 53. The distal sleeve portion 54 is connected to the distal end of the distal tapered portion 52. The proximal sleeve portion 55 is connected to the proximal end of the proximal tapered portion 53. The distal sleeve portion 54 and the proximal sleeve portion 55 are formed in a substantially cylindrical shape.

[0044] It is preferable that the second cylindrical portion 20 extends distally from the distal end of the first cylindrical portion 10, and the second cylindrical portion 20 extends through the inner space of the balloon 50 from the proximal sleeve portion 55 to the distal sleeve portion 54. It is preferable that an outer surface of the second cylindrical portion 20 is joined to an inner surface of the distal sleeve portion 54 of the balloon 50, and an outer surface of the first cylindrical portion 10 is joined to an inner surface of the proximal sleeve portion 55 of the balloon 50. By configuring the distal portion of the second cylindrical portion 20 in this manner, balloon expansion fluid can be supplied to the inner space of the balloon 50 through the space between the first cylindrical portion 10 and the second cylindrical portion 20.

[0045] The balloon 50 is preferably made of a resin, more preferably made of a thermoplastic resin. This facilitates manufacturing the balloon 50 by molding. Examples of the resin constituting the balloon 50 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; polyester resins such as polyethylene terephthalate and polyester elastomer; polyurethane resins such as polyurethane and polyurethane elastomer; polyphenylene sulfide resin; polyamide resins such as polyamide and polyamide elastomer; fluorine-based resins, silicone resins, and natural rubbers such as latex rubber. Only one of these may be used alone, or two or more thereof may be used in combination. Among these, polyamide resins, polyester resins and polyurethane resins are preferably used. In particular, an elastomer resin is preferably used from the viewpoints of thinning the balloon 50 and imparting flexibility thereto. For example, among polyamide resins, suitable materials for the balloon 50 include nylon 12, nylon 11 and the like, and nylon 12 is preferably used because it can be molded relatively easily during blow molding. Further, from the viewpoints of thinning the balloon 50 and imparting flexibility thereto, polyamide elastomers such as polyether ester amide elastomer and polyamide ether elastomer are preferably used. Among these, polyether ester amide elastomer is preferably used because of its high yield strength and good dimensional stability of the balloon 50.

[0046] A distal tip 56 may be disposed at the distal end portion of the distal shaft 45. The distal tip 56 may be provided as a separate member from the second cylindrical portion 20 on the distal side relative to the distal end of the second cylindrical portion 20, or the distal end portion of the second cylindrical portion 20 may function as the distal tip 56 by the second cylindrical portion 20 extending to the distal side beyond the distal end of the balloon 50. The distal tip 56 may have a through hole extending in the longitudinal direction x.

[0047] As shown in Figures 1, 3 and 4, a protective tube 70 enclosing the balloon 50 may be provided. The protective tube 70 is a member that protects the balloon 50 in a folded state to prevent damage to the balloon 50 before use. It is preferable that the protective tube 70 has a lumen in which the folded balloon 50 is disposed.

[0048] Examples of the material constituting the protective tube 70 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorine resins, vinyl chloride resins, silicone resins, natural rubber, and the like. Only one of these may be used alone, or two or more thereof may be used in combination.

[0049] In the longitudinal direction x, the protective tube 70 is preferably longer than the balloon 50. Since the entire balloon 50 can be accommodated in the protective tube 70, damage to the balloon 50 can be easily prevented.

[0050] As shown in Figures 1, 3 to 5, the catheter 1 preferably has a wire 75 inserted into the second lumen 21 from the distal end 4 side. It is preferable that the wire 75 is inserted into the second lumen 21 in the pre-use state of the catheter 1, for example, in a packaged state. By inserting the wire 75, the shapes of the balloon 50 and the second lumen 21 can be protected. The wire 75 is pulled out from the distal end 4 side before the catheter 1 is used.

[0051] The wire 75 is preferably inserted from the distal end 21B to the proximal end 21A of the second lumen 21, and more preferably from the distal end 4 of the catheter body 2 to the proximal end 21A of the second lumen 21. For this reason, the wire 75 is preferably long. The wire 75 may have a solid shape or a hollow shape, and a part of the wire 75 in the longitudinal direction may have a solid shape and the other part may have a hollow shape.

[0052] The wire 75 may be a metal wire or a resin wire. A metal wire is a wire made of metal, and examples of metals include copper, iron, stainless steel, tungsten, nickel-titanium alloy, and carbon steel. Among these, stainless steel is preferred from the viewpoint of strength. A resin wire is a wire made of resin, and examples of resins include polyamide resins such as nylon, polyimide resins, polyester resins such as PET, and aromatic polyetherketone resins such as PEEK.

[0053] As shown in Figures 1 and 2, the catheter body 2 has a twisted portion 40 that is twisted clockwise around the axis of the longitudinal direction x in the section of the longitudinal direction x where the second lumen 21 is located. Because the catheter 1 has a twisted portion 40, the catheter 1 can easily follow the shape of the internal lumen without the user having to twist it at the proximal end, thus allowing the catheter 1 to be smoothly delivered to the lesion. Furthermore, since internal lumens such as blood vessels and the digestive tract may have a clockwise spiral shape depending on the location, the presence of the clockwise twisted portion 40 of the catheter body 2 makes it even easier to conform to the shape of the internal lumen. Here, the axis of the longitudinal direction x can also be called the central axis of the longitudinal direction x.

[0054] In this specification, "twisted portion 40" or "twisted" refers to a portion or state in which the direction of extension along the longitudinal axis x of the catheter body 2 has changed due to a rotational operation applied to a part of the catheter body 2. In other words, the direction of extension of the twisted portion 40 of the catheter body 2 is deflected relative to the direction of extension of the portion in which the twisted portion 40 is not formed. The twisted portion 40 may be formed by twisting and heating the catheter body. For example, when inserting a straight or flatly curved catheter body into the lumen of a tubular body for shaping or packaging, the catheter body may be twisted by adjusting the insertion direction of the catheter body or by bringing the tip of the catheter body into contact with the inner wall surface of the tubular body, and then the twisted portion 40 may be formed by sterilizing and / or heating the tubular body. Note that cooling may be performed after sterilization and / or heating. The curved tubular body may be, for example, an arc-shaped or spiral-shaped tubular body.

[0055] A clockwise twist means that, when the catheter body 2 is viewed from the distal or proximal side, it is formed so that, with respect to the longitudinal axis x of the catheter body 2, the catheter body 2 rotates clockwise in the circumferential direction z as it moves toward the distal or proximal side. Preferably, the distal end 4 of the catheter body 2 is twisted clockwise relative to the proximal end 3. Here, a clockwise twist of the distal end 4 of the catheter body 2 relative to the proximal end 3 means that, with respect to any position in the longitudinal x of the catheter body 2 as a reference point, the portion on the distal end 4 side of the reference point is twisted clockwise around the axis of the catheter body 2 relative to the portion on the proximal end 3 side of the reference point.

[0056] In the longitudinal direction x of the catheter body 2, the twisted portion 40 may be located at only one location or at multiple locations.

[0057] Preferably, the twisted portion 40 is located only on a part of the longitudinal direction x of the catheter body 2. Preferably, the twisted portion 40 extends along the longitudinal direction x of the catheter body 2 and has a predetermined length.

[0058] The twisted portion 40 may have a constant twist angle from its distal end to its proximal end, or the twist angle may change linearly toward the distal or proximal side, or it may change exponentially or nonlinearly toward the distal or proximal side. A change in the twist angle includes both an increase and a decrease in the twist angle. The twist angle is the rotation angle of the twisted portion 40 and means the rotation angle of the cross-section of the catheter body 2 at a different position in the longitudinal direction x relative to a reference position which is any position in the longitudinal direction x of the catheter body 2. Here, the cross-section is the cross-section of the catheter body 2 perpendicular to the longitudinal direction x. Hereafter, the cross-section of the catheter body 2 perpendicular to the longitudinal direction x may simply be referred to as the cross-section of the catheter body 2.

[0059] The twist angle (rotation angle) is preferably 90° or less, more preferably 85° or less, and even more preferably 80° or less. Furthermore, the twist angle is preferably 5° or more, more preferably 10° or more, and even more preferably 15° or more.

[0060] The twisted portion 40 is preferably located in a section of the longitudinal direction x where both the first lumen 11 and the second lumen 21 exist. The twisted portion 40 may also be located in a section of the longitudinal direction x where only the first lumen 11 exists. The twisted portion 40 may also be located in a section of the longitudinal direction x where only the second lumen 21 exists. The twisted portion 40 may also be located only in a section of the longitudinal direction x where both the first lumen 11 and the second lumen 21 exist.

[0061] In the longitudinal direction x, the length of the twisted portion 40 may be the same as the length of the section in which the second lumen 21 exists, or it may be longer or shorter than this.

[0062] The twisted portion 40 is preferably located within 30 cm proximally from the distal end 4 of the catheter body 2, but may also be located within 25 cm or within 20 cm. That is, the proximal end of the twisted portion 40 is preferably located 30 cm proximally from the distal end 4 of the catheter body 2, or distal to this position. The distal end of the twisted portion 40 is preferably coinciding with the distal end 4 of the catheter body 2.

[0063] The twisted portion 40 may overlap with the balloon 50 in the longitudinal direction x. The twisted portion 40 may be located in the range from the proximal end of the balloon 50 to the proximal end 21A of the second lumen 21. The twisted portion 40 does not have to overlap with the balloon 50 in the longitudinal direction x.

[0064] The distal end of the twisted portion 40 may overlap with the distal end 21B of the second lumen 21 in the longitudinal direction x. In the longitudinal direction x, the distal end of the twisted portion 40 may be located distal to the distal end 21B of the second lumen 21. In the longitudinal direction x, the distal end of the twisted portion 40 may be located between the distal end 21B of the second lumen 21 and the distal end 11B of the first lumen 11. In the longitudinal direction x, the distal end of the twisted portion 40 may be located proximal to the distal end 11B of the first lumen 11.

[0065] The proximal end of the twisted portion 40 may overlap with the proximal end 21A of the second lumen 21 in the longitudinal direction x. In the longitudinal direction x, the proximal end of the twisted portion 40 may be located distal to the proximal end 21A of the second lumen 21. In the longitudinal direction x, the proximal end of the twisted portion 40 may be located distal to the proximal end 11B of the first lumen 11. In the longitudinal direction x, the proximal end of the twisted portion 40 may be located between the distal end 21B of the second lumen 21 and the distal end 11B of the first lumen 11.

[0066] In the longitudinal direction x, the length of the twisted portion 40 may be the same as the length of the balloon 50, or it may be longer or shorter. In the longitudinal direction x, the length of the twisted portion 40 may be the same as the length of the second lumen 21, or it may be longer or shorter.

[0067] Preferably, the catheter body 2 has a curved portion 30 in at least a part of its longitudinal direction x. The curved portion 30 is a part formed by the curving or bending of at least a part of the catheter body 2. Preferably, the curved portion 30 is a part of the catheter body 2 that is curved. This allows the extending direction of the catheter 1 to change smoothly.

[0068] The catheter body 2 preferably has a bent portion 30 at its distal end, but it may also have a bent portion 30 at its proximal end, or it may have a bent portion 30 along its entire longitudinal direction x.

[0069] The curved portion 30 of the catheter body 2 may have a planar shape or a three-dimensional shape. The curved portion 30 having a planar shape has a shape that follows a specific plane. The curved portion 30 having a three-dimensional shape is formed to trace a trajectory that continuously changes in multiple directions in space. In such a curved portion 30 having a three-dimensional shape, it may have a shape that includes twisting in addition to bending in a single plane. That is, as can be seen from Figure 1, the curved portion 30 may have a twisted portion 40. This makes it easier for the extending direction of the catheter body 2 to follow the shape of the lumen inside the body, so that the catheter 1 can be smoothly transported to the lesion.

[0070] The curved portion 30 is preferably a part that curves along a specific plane while having a constant curvature. The curved portion 30 is preferably a specific radius of curvature. The radius of curvature R is, for example, 5 cm or more and 50 cm or less.

[0071] In the curved section 30, the radius of curvature may change locally. The minimum radius of curvature of the curved section 30 can be, for example, 5 cm or more and 50 cm or less. The average radius of curvature of the curved section 30 can be, for example, 5 cm or more and 100 cm or less. The minimum radius of curvature is the radius of curvature of the most strongly curved part of the catheter body 2. The average radius of curvature is the average value of the overall radius of curvature of the catheter body 2.

[0072] The curved portion 30 may have an arc shape. That is, at least a part of the curved portion 30 may be curved in an arc along an arbitrarily placed plane. Alternatively, the curved portion 30 may have a spiral shape. That is, the catheter body 2 may be wound in a planar manner in the curved portion 30. In that case, the overall shape of the wound portion may be bent to be annular, preferably circular or oval. The oval shape includes elliptical, egg-shaped, and rounded rectangular shapes. The same applies in the following description.

[0073] In the longitudinal direction x, the twisted portion 40 may be arranged over the entire curved portion 30, but it is preferable that the twisted portion 40 is arranged over only a part of the curved portion 30.

[0074] The curved portion 30 may be distributed along the entire longitudinal direction x of the catheter body 2, or it may be distributed along only a part of the longitudinal direction x. In other words, the rest of the catheter body 2 in the longitudinal direction may have a straight shape.

[0075] As shown in Figures 2 and 7, when the catheter is placed on a horizontal plane p, it is preferable that only a portion of the longitudinal direction x of the catheter body is in contact with the horizontal plane p. The horizontal plane p is a plane perpendicular to the vertical direction q. Because a portion of the longitudinal direction x of the catheter body 2 is in contact with the horizontal plane p in this way, the catheter 1 can be said to have a three-dimensional structure. This makes it easier to conform to the shape of the lumen inside the body, allowing the catheter 1 to be smoothly transported to the lesion.

[0076] As shown in Figure 2, when the catheter 1 is placed on a horizontal plane p, it is preferable that the distal end of the catheter body 2 is floating above the horizontal plane p, and the remaining portion of the catheter body 2 in the longitudinal direction x is in contact with the horizontal plane p. Having a three-dimensional structure in this way makes it easier for the catheter 1 to conform to the shape of the body lumen, thus allowing the catheter 1 to be smoothly transported to the lesion.

[0077] As shown in Figure 7, when the catheter 1 is placed on a horizontal plane p, it is preferable that the middle portion 9 in the longitudinal direction x of the catheter body 2 is floating above the horizontal plane p, and that the portion distal to the middle portion 9 and the portion proximal to the middle portion 9 of the catheter body 2 are in contact with the horizontal plane p. In Figure 7, at least the proximal end 3 and distal end 4 of the catheter body 2 are in contact with the horizontal plane p. Even with such a three-dimensional structure, the catheter 1 can easily conform to the shape of the internal lumen, so that the catheter 1 can be smoothly transported to the lesion.

[0078] As shown in Figure 5, when the catheter 1 is placed on a horizontal plane p, it is preferable that the second lumen 21 is located below the first lumen 11 in the vertical direction q at the position of its proximal end 21A. This makes it easier for the guidewire inserted into the second lumen 21 to float above the horizontal plane p, thereby improving the operability when inserting the guidewire into the second lumen 21. Note that the upper side of Figure 5 is above the vertical direction q, and the lower side of Figure 5 is below the vertical direction q, and the same applies to Figure 8.

[0079] As shown in Figure 8, when the catheter 1 is placed on a horizontal plane p, it is preferable that the second lumen 21 is located above the first lumen 11 in the vertical direction q at the position of its proximal end 21A. This makes it easier for the guidewire inserted into the second lumen 21 to come into contact with the horizontal plane p, and for the guidewire to follow the horizontal plane p. Therefore, it becomes easier to perform the guidewire insertion operation into the second lumen 21 stably.

[0080] As shown in Figure 1, it is preferable that a handle 60 is connected to the proximal end of the catheter body 2. The handle 60 is the part that the user grasps with their hand when operating the catheter 1, and by grasping and pressing the handle 60, the catheter 1 can be inserted into the body. The handle 60 may also function as a hub or manifold. A hub is used to connect the catheter body 2 to external equipment. A manifold is used for the distribution and control of fluid pathways.

[0081] The handle 60 should have a shape and size that is easy for the user to grasp. The handle 60 may, for example, have a cylindrical shape. The handle 60 may have a hollow portion extending in the longitudinal direction x. Preferably, the hollow portion is in communication with the first lumen 11. The handle 60 may have a fluid injection portion in communication with the hollow portion. A syringe or the like may be connected to the fluid injection portion for injecting fluids such as fluid for expanding the balloon 50 via the first lumen 11, contrast agent, or drug solution.

[0082] The handle 60 may have a bifurcated structure. In that case, it is preferable that a fluid injection section is provided on one of the bifurcated ends.

[0083] The handle 60 is preferably a resin molded product obtained by injection molding or the like. The resin can be, for example, a polyolefin resin such as polyethylene or polypropylene, a polyamide resin such as nylon, a polyester resin such as PET, an aromatic polyetherketone resin such as PEEK, a polyetherpolyamide resin, a polyurethane resin, a polyimide resin, a fluororesin such as PTFE, PFA, or ETFE, a polyvinyl chloride resin, a carbonate resin, a styrene resin, or a (meth)acrylic resin. Among these resins, transparent resins such as polycarbonate and polymethyl methacrylate are preferred.

[0084] The proximal end of the catheter body 2 is preferably located within the handle 60. This improves pushability.

[0085] The handle 60 may have a cross-sectional shape with a minor axis and a major axis in a cross-section perpendicular to the longitudinal direction x. In that case, the angle θ between the direction SD of the minor axis of the handle 60 and the alignment direction 2P of the first lumen 11 and the second lumen 21 in the radial direction y at position 2M is preferably 45° or less, more preferably 30° or less, even more preferably 20° or less, and even more preferably 0°. The alignment direction 2P of the first lumen 11 and the second lumen 21 is more preferably the direction of extension of the straight line connecting the centroid 11C of the first lumen and the centroid 21C of the second lumen at position 2M.

[0086] The major axis of the cross-sectional shape of the handle 60 refers to the length of the major axis direction LD of the outer circumference of the handle 60 (the maximum outer diameter of the outer edge), and the minor axis refers to the length of the minor axis direction SD of the outer circumference of the handle 60, which is perpendicular to the major axis of the handle 60. Here, it is preferable that the cross-sectional shape is the cross-sectional shape at the position where the outer diameter of the handle 60 is maximum. Here, the outer diameter of the handle 60 refers to the diameter equivalent to a circle. If there are multiple positions where the outer diameter of the handle 60 is maximum, or if the outer diameter of the handle 60 is maximum within a predetermined range in the longitudinal direction x, it is more preferable that the cross-sectional shape is the cross-sectional shape at the central position in the longitudinal direction within the range where the outer diameter of the handle 60 is maximum. The position where the outer diameter of the handle 60 is maximum may be an intermediate point in the longitudinal direction x from the proximal end to the distal end of the handle 60, the central position of the handle 60 in the longitudinal direction x, or the position of the proximal end of the handle 60.

[0087] This application claims the benefit of priority based on Japanese Patent Application No. 2025-38553, filed on 11 March 2025. The entire specification of Japanese Patent Application No. 2025-38553, filed on 11 March 2025, is incorporated herein by reference.

[0088] 1: Catheter 2: Catheter body 3: Proximal end 4: Distal end 10: First tube 11: First lumen 11A: Proximal end of first lumen 11B: Distal end of first lumen 12: First inner surface 20: Second tube 20F: Proximal opening of second lumen 20G: Distal opening of second lumen 21: Second lumen 21A: Proximal end of second lumen 21B: Distal end of second lumen 22: Second inner surface 30: Curved section 40: Twisted section 45: Distal shaft 46: Proximal shaft 50: Balloon 51: Straight section 52: Distal tapered section 53: Proximal tapered section 54: Distal sleeve section 55: Proximal sleeve section 56: Tip 60: Handle 70: Protective tube 75: Wire 2M: The most proximal position where the first inner surface and the second inner surface are present around the entire circumference 2N: The most distal position where the first inner surface and the second inner surface are present around the entire circumference x: Longitudinal direction y: Radial direction z: Circumferential direction p: Horizontal plane q: Vertical direction SD: Short axis direction

Claims

1. A catheter having a longitudinal direction, the catheter body having a first lumen and a second lumen whose proximal end is located distal to the proximal end of the first lumen and which is enclosed within the first lumen, wherein the catheter body has a torsion portion in the longitudinal direction in the section where the second lumen is located, which is twisted clockwise around the axis of the longitudinal direction.

2. The catheter according to claim 1, wherein when the catheter is placed on a horizontal surface, only a portion of the catheter body in the longitudinal direction is in contact with the horizontal surface.

3. The catheter according to claim 2, wherein when the catheter is placed on a horizontal surface, the distal end of the catheter body is floating above the horizontal plane, and the remaining longitudinal portion of the catheter body is in contact with the horizontal plane.

4. The catheter according to claim 2, wherein when the catheter is placed on a horizontal surface, the midpoint of the catheter body in the longitudinal direction is floating above the horizontal plane, and the distal portion of the catheter body and the proximal portion of the catheter body are in contact with the horizontal plane.

5. The catheter according to claim 1 or 2, wherein when the catheter is placed in a horizontal plane, the second lumen is located vertically lower than the first lumen at the position of its proximal end.

6. The catheter according to claim 1 or 2, wherein, when the catheter is placed in a horizontal plane, the second lumen is located vertically above the first lumen at the position of its proximal end.

7. The catheter according to claim 1 or 2, wherein the twisted portion is located within 30 cm from the distal end of the catheter body toward the proximal end.

8. The catheter according to claim 1 or 2, wherein a balloon is disposed at the distal end of the catheter body, and the first lumen is in communication with the inside of the balloon.

9. The catheter according to claim 1 or 2, having a wire inserted into the second lumen from the distal end of the catheter.

Images