JP2022132890A - balloon catheter - Google Patents

Abstract

To improve torque transmissibility of a balloon catheter.SOLUTION: A balloon catheter includes: a balloon; a cylindrical outer shaft with a proximal end of the balloon fixed to a tip end; a cylindrical inner shaft housed in the hollow part of the balloon and the outer shaft, and having the tip end of the balloon fixed to the tip end; and a coil body arranged in a space formed between an outer circumferential surface of the inner shaft and an inner circumferential surface of the outer shaft, having the tip end fixed to the inner shaft, and having the proximal end fixed to the outer shaft or the inner shaft. The coil body is arranged separately from the inner circumferential surface of the outer shaft. The coil body has a first intermediate part being not fixed to the outer circumferential surface of the inner shaft between the outer circumferential surface of the inner shaft and the inner circumferential surface of the outer shaft.SELECTED DRAWING: Figure 1

Description

The technology disclosed herein relates to balloon catheters.

A balloon catheter is an elongated medical device that is inserted into a body cavity such as a blood vessel in order to spread and dilate a lesion (stenosis or occlusion) in the body cavity. A balloon catheter includes a balloon, a tubular outer shaft, and a tubular inner shaft housed in a hollow portion of the balloon and the outer shaft. The distal end of the balloon is fixed to the distal end of the inner shaft, and the proximal end of the balloon is fixed to the distal end of the outer shaft. A hollow portion of the inner shaft functions as a guide wire lumen for passing a guide wire. In addition, the space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft supplies fluid (contrast medium, physiological saline, etc.) for expanding the balloon toward the inner space of the balloon. Acts as an extended fluid lumen for

Conventionally, in order to improve the ability of a technician such as a doctor to transmit the force that pushes the proximal end of the balloon catheter in the axial direction to the distal end of the balloon catheter (hereinafter referred to as "pushing force transmissibility"), an inner shaft A balloon catheter is known in which a metallic net-like body is embedded inside the side wall of the catheter (see, for example, Patent Document 1).

JP-A-10-57495

In the balloon catheter, in addition to the pushing force transmissibility described above, the ability to transmit the force of the operator rotating the proximal end of the balloon catheter around the axial direction to the distal end of the balloon catheter (hereinafter referred to as "rotational force transmissibility") ) is useful. For example, when the distal end of the balloon catheter is caught in a relatively hard lesion and the balloon catheter cannot be advanced any further, the operator rotates the proximal end of the balloon catheter in the axial direction to move the distal end of the balloon catheter. If the direction of the portion can be changed, the catching can be eliminated and there is a possibility that there will be no hindrance to advancement of the balloon catheter.

In the configuration of the conventional balloon catheter described above, the mesh-like body made of metal is embedded inside the side wall of the inner shaft, and the mesh-like body cannot deform independently of the inner shaft. cannot be effectively transmitted to the distal end, and the rotational force transmission of the balloon catheter cannot be improved.

This specification discloses a technology capable of solving the above-described problems.

The technology disclosed in this specification can be implemented, for example, in the following forms.

(1) The balloon catheter disclosed in the present specification comprises a balloon, a cylindrical outer shaft having a proximal end portion of the balloon fixed to a distal end portion, and a hollow portion of the balloon and the outer shaft. The balloon is arranged in a space formed between a tubular inner shaft having a distal end portion to which the distal end portion of the balloon is fixed, an outer peripheral surface of the inner shaft, and an inner peripheral surface of the outer shaft. a coil body having a portion fixed to the inner shaft and a base end portion fixed to the outer shaft or the inner shaft. The coil body is spaced apart from the inner peripheral surface of the outer shaft. The coil body has a first intermediate portion, which is not fixed to the outer peripheral surface of the inner shaft, between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft.

Thus, the present balloon catheter comprises a coil body having a distal end fixed to the inner shaft and a proximal end fixed to the outer shaft or the inner shaft. The coil body is disposed apart from the inner peripheral surface of the outer shaft, and is not fixed to the outer peripheral surface of the inner shaft between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft. has an intermediate portion of Therefore, the first intermediate portion of the coil body can deform independently of the outer shaft and the inner shaft. Therefore, in the present balloon catheter, the rotation of the proximal end of the balloon catheter can be effectively transmitted to the inner shaft due to the presence of the first intermediate portion of the coil body, thereby improving the rotational force transmissibility of the balloon catheter. can be done. In addition, since the coil body is spaced apart from the inner peripheral surface of the outer shaft, even if the outer shaft is bent and pressed against the inner wall of the blood vessel and becomes difficult to move, the outer shaft allows the coil body to move. is restrained, the deformation of the coil body is prevented from being hindered by the outer shaft, and the rotational force transmissibility of the balloon catheter can be effectively improved.

(2) In the above balloon catheter, the outer shaft includes a distal outer shaft to which the proximal end of the balloon is fixed at the distal end, and a proximal outer shaft connected to the proximal end of the distal outer shaft. and , and the proximal end of the coil body may be fixed to the distal end of the proximal-side outer shaft. In the present balloon catheter, since the proximal end of the coil body is fixed to the distal end of the proximal outer shaft, the joint strength between the coil body and the outer shaft can be easily improved. The presence of the first intermediate portion of the can effectively improve the rotational force transmissibility of the balloon catheter.

(3) In the above balloon catheter, the proximal outer shaft may be made of metal. According to the present balloon catheter, the joint strength between the coil body and the outer shaft can be more easily improved, and the presence of the first intermediate portion of the coil body makes the rotational force transmissibility of the balloon catheter more effective. can be improved to

(4) In the above balloon catheter, the coil body may have the first intermediate portion over the entire length of the distal outer shaft. According to the present balloon catheter, in the coil body, the length of the first intermediate portion that can be deformed independently of the outer shaft and the inner shaft can be sufficiently secured, and the rotational force transmissibility of the balloon catheter can be improved. can be effectively improved.

(5) In the above balloon catheter, a first portion positioned distally of the proximal outer shaft; and a first portion positioned distally of the first portion and proximally of the balloon; A second portion having a lower rigidity than the first portion may be provided. According to this balloon catheter, the rigidity of the balloon catheter can be gradually changed on the distal side of the proximal outer shaft so that the rigidity decreases toward the distal side. Therefore, according to the present balloon catheter, it is possible to alleviate the rigidity gap of the balloon catheter caused by the outer shaft being composed of the distal outer shaft and the proximal outer shaft.

(6) In the above balloon catheter, the number of turns per unit length of the coil body in the first portion may be greater than the number of turns per unit length of the coil body in the second portion. . According to the present balloon catheter, it is possible to reduce the rigidity gap of the balloon catheter while suppressing an increase in the number of parts.

(7) The balloon catheter further includes a core wire disposed in the first portion, having a proximal end fixed to the distal end of the proximal outer shaft, and extending along the axial direction of the distal outer shaft. It is good also as a structure provided. According to the present balloon catheter, even when using a coil body having a simple configuration in which the number of turns per unit length is substantially constant, the stiffness gap of the balloon catheter can be alleviated.

(8) In the above balloon catheter, the distal end portion of the coil body may be fixed to the distal end portion of the inner shaft. According to this balloon catheter, the rotation of the proximal end of the balloon catheter can be effectively transmitted to the distal end of the inner shaft by the coil body, and the rotational force transmissibility of the balloon catheter can be effectively improved. .

(9) In the above balloon catheter, the coil body has a second intermediate portion, which is not fixed to the outer peripheral surface of the inner shaft, between the outer peripheral surface of the inner shaft and the inner peripheral surface of the balloon. may be In this balloon catheter, the second intermediate portion of the coil body can be deformed independently of the inner shaft and the balloon. The torque can be transmitted to the inner shaft more effectively, and the torque transmission of the balloon catheter can be effectively improved.

(10) In the above balloon catheter, the coil body may have the second intermediate portion over the entire length of the internal space of the balloon. According to the present balloon catheter, in the coil body, it is possible to secure a sufficient length of the second intermediate portion that can be deformed independently of the inner shaft and the balloon, thereby improving the rotational force transmissibility of the balloon catheter. can be substantially improved.

(11) In the above balloon catheter, the distal end portion of the coil body may be fixed at a position on the inner shaft that is aligned with the proximal end portion of the balloon or at a position closer to the proximal end than the position. According to the present balloon catheter, since the coil body is not arranged in the internal space of the balloon, it is possible to avoid an increase in the outer diameter of the deflated balloon due to the presence of the coil body. Passability can be improved.

(12) In the above balloon catheter, the coil body may have a structure in which a single wire is helically wound. According to the present balloon catheter, the ease of deformation of the coil body can be improved, and the presence of the coil body can further effectively improve the rotational force transmissibility of the balloon catheter. In addition, according to the present balloon catheter, even if the coil body is arranged between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft, it is possible to effectively suppress the obstruction of the expansion fluid flow by the coil body. can do.

(13) In the above balloon catheter, the coil body may have a structure in which a plurality of wires are spirally wound. According to the present balloon catheter, the presence of the coil body enables the rotation of the proximal end portion of the balloon catheter to be more effectively transmitted to the inner shaft, thereby further effectively improving the rotational force transmissibility of the balloon catheter. can.

(14) In the above balloon catheter, the coil body may be a loosely wound coil body. According to the present balloon catheter, the ease of deformation of the coil body can be improved, and the presence of the coil body can more effectively transmit the rotation of the proximal end portion of the balloon catheter to the inner shaft. It is possible to further effectively improve the rotational force transmissibility. In addition, according to the present balloon catheter, even if the coil body is arranged between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft, it is possible to effectively suppress the obstruction of the expansion fluid flow by the coil body. can do.

(15) In the above balloon catheter, the coil body may be a tightly wound coil body. According to the present balloon catheter, the durability of the coil body can be improved, and thus the durability of the balloon catheter can be improved.

(16) In the above balloon catheter, the wire may be composed of a single wire. According to the present balloon catheter, simplification of the configuration and facilitation of manufacturing can be achieved.

(17) In the above balloon catheter, the wire may be a twisted wire obtained by twisting a plurality of strands. According to the present balloon catheter, the durability of the coil body can be improved, and thus the durability of the balloon catheter can be improved.

(18) In the above balloon catheter, the inner shaft may have a shaft body and a tip provided at the distal end of the shaft body. According to the present balloon catheter, it is possible to improve the rotational force transmissibility of the balloon catheter while improving the flexibility of the distal end portion of the balloon catheter.

The technology disclosed in this specification can be implemented in various forms, for example, in the form of a balloon catheter and a manufacturing method thereof.

Explanatory drawing schematically showing the configuration of the balloon catheter 100 in the first embodiment. Explanatory drawing schematically showing the configuration of the balloon catheter 100a in the second embodiment. Explanatory drawing schematically showing the configuration of a balloon catheter 100b in the third embodiment. Explanatory drawing schematically showing the configuration of a balloon catheter 100c according to the fourth embodiment.

A. First embodiment:
A-1. Configuration of balloon catheter 100:
FIG. 1 is an explanatory diagram schematically showing the configuration of a balloon catheter 100 according to the first embodiment. FIG. 1 shows the configuration of the longitudinal section (YZ section) of the balloon catheter 100. As shown in FIG. However, for convenience of illustration, the configuration of part of the balloon catheter 100 is shown in the side configuration rather than the cross-sectional configuration, and the configuration of part of the balloon catheter 100 is omitted. FIG. 1 shows a balloon 30, described below, in an inflated state. In FIG. 1, the Z-axis positive direction side is the tip side (distal side) inserted into the body, and the Z-axis negative direction side is the proximal side (proximal side) operated by an operator such as a doctor. . Although FIG. 1 shows the balloon catheter 100 as a whole in a straight line parallel to the Z-axis direction, the balloon catheter 100 has flexibility to the extent that it can be curved. In this specification, with respect to the balloon catheter 100 and its components, the distal end is referred to as the "distal end", the distal end and its vicinity as the "distal end", and the proximal end as the "proximal end". The base end and the vicinity thereof are referred to as the "base end".

A balloon catheter 100 is an elongated medical device that is inserted into a body cavity such as a blood vessel in order to spread and dilate a lesion (stenosis or occlusion) in the body cavity. The total length of the balloon catheter 100 is, for example, approximately 1500 mm. A balloon catheter 100 includes an inner shaft 10 , an outer shaft 20 , a balloon 30 and a coil body 40 .

The outer shaft 20 is a tubular (for example, cylindrical) member with an open distal end and a proximal end. In this specification, the term “cylindrical (cylindrical)” is not limited to a complete cylindrical shape (cylindrical shape), but generally a substantially cylindrical shape (substantially cylindrical shape, for example, a slightly conical shape, a partial It means that it is a shape with unevenness, etc.). In this embodiment, the outer shaft 20 is composed of a distal outer shaft 23 and a proximal outer shaft 27 . The proximal outer shaft 27 is connected to the proximal end of the distal outer shaft 23 so as to be substantially coaxial with the distal outer shaft 23 . Further, in the present embodiment, the distal outer shaft 23 has a small diameter portion 21 and a large diameter portion 22 connected to the base end of the small diameter portion 21 and having an outer diameter and an inner diameter larger than the small diameter portion 21. . The outer diameter of each portion of the outer shaft 20 is, for example, approximately 0.2 mm to 2.0 mm.

The distal end side outer shaft 23 is made of a material that can be heat-sealed and has a certain degree of flexibility. As the material for forming the distal end side outer shaft 23, for example, a resin can be used. More specifically, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or these can be used. Polyolefins, polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, thermoplastic polyurethanes, etc., such as mixtures of two or more thereof, can be used. In addition, the proximal-side outer shaft 27 is made of a hypotube. As a material for forming the base end side outer shaft 27, for example, metal can be used, and more specifically, stainless steel (SUS302, SUS304, SUS316, etc.) or the like can be used.

The inner shaft 10 is a cylindrical (for example, cylindrical) member having open ends and base ends. In this embodiment, the inner shaft 10 has a shaft body 11 and a tip 12 connected to the tip of the shaft body 11 .

The outer diameter of the inner shaft 10 is smaller than the inner diameter of the outer shaft 20 , and the inner shaft 10 is housed in the hollow portion of the outer shaft 20 so as to be substantially coaxial with the outer shaft 20 . The distal end portion of the inner shaft 10 (the distal end portion of the shaft body 11 and the tip 12 ) protrudes from the distal end of the outer shaft 20 toward the distal end side (Z-axis positive direction side). In addition, the proximal end of the inner shaft 10 extends to the proximal end of the outer shaft 20 (the proximal outer shaft 27). That is, the balloon catheter 100 of this embodiment is a so-called over-the-wire (OTW) type balloon catheter.

The inner shaft 10 is made of a material that can be heat-sealed and has a certain degree of flexibility. As the material for forming the inner shaft 10, the same material as the material for forming the distal end side outer shaft 23 described above can be used.

A hollow portion of the inner shaft 10 functions as a guide wire lumen S1 for inserting a guide wire (not shown). The guide wire lumen S1 communicates with a guide wire port 62 in a Y connector 60 connected to the proximal end of the proximal outer shaft 27 . A guide wire inserted into the guide wire lumen S1 through the guide wire port 62 is led out from an opening formed at the distal end of the inner shaft 10 (the distal end of the tip 12). A protective tube 70 made of a flexible resin such as elastomer or polyurethane is arranged at the connecting portion between the Y connector 60 and the base end side outer shaft 27 .

In addition, the space formed between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 26 of the outer shaft 20 is filled with a fluid (contrast agent or physiological fluid) for expanding the balloon 30 toward the inner space S3 of the balloon 30. function as an expansion fluid lumen S2 that supplies saline solution). The expansion fluid lumen S2 communicates with an expansion fluid port 64 in a Y connector 60 connected to the proximal end of the proximal outer shaft 27 .

The balloon 30 is a hollow member in which an internal space S3 is formed, and can be expanded and contracted as fluid is supplied and discharged. The balloon 30 covers a portion of the inner shaft 10 protruding from the tip of the outer shaft 20 . The distal end of the balloon 30 is fixed to the distal end of the inner shaft 10 by, for example, welding. tip), for example by welding.

As a material for forming the balloon 30, for example, resin or rubber can be used. More specifically, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or these can be used. Polyolefins such as mixtures of two or more kinds, soft polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, thermoplastic resins such as fluororesins, silicone rubbers, latex rubbers, and the like can be used.

A-2. Configuration of coil body 40:
Next, the configuration of the coil body 40 will be described. The coil body 40 has a structure in which a wire 44 is spirally wound. In the present embodiment, the coil body 40 has a structure in which a wire rod 46 is spirally wound, which is composed of a plurality of (specifically, three) wires 44 each composed of a single wire. is doing. In this embodiment, each wire 44 has a substantially rectangular cross section perpendicular to the axial direction (the long side is substantially parallel to the axial direction of the balloon catheter 100 and the short side is substantially parallel to the radial direction of the balloon catheter 100). It is composed of flat lines that are rectangles).

Further, in the present embodiment, the coil body 40 is a loosely wound coil body. That is, the wire rod 46 made up of the three wires 44 described above is wound around the coil body 40 in such a manner that portions adjacent to each other in the axial direction are spaced apart from each other.

As a material for forming the coil body 40, for example, metal can be used, and more specifically, stainless steel (SUS302, SUS304, SUS316, etc.) or the like can be used.

The coil body 40 is arranged in the space formed between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 26 of the outer shaft 20, that is, the expansion fluid lumen S2. In other words, the coil body 40 has a structure in which the wire rod 46 is wound around the inner shaft 10 . The distal end of the coil body 40 protrudes from the distal end of the outer shaft 20 toward the distal end (positive direction of the Z axis) into the internal space S3 of the balloon 30, and is fixed to the distal end of the inner shaft 10 by, for example, brazing. It is Further, the proximal end portion of the coil body 40 is fixed to the distal end portion of the proximal-side outer shaft 27 constituting the outer shaft 20 by, for example, welding or brazing.

The coil body 40 is arranged apart from the inner peripheral surface 26 of the outer shaft 20 (more specifically, the distal end side outer shaft 23). That is, the coil body 40 is not in contact with the inner peripheral surface 26 of the distal outer shaft 23 . Further, the coil body 40 has a first intermediate portion 41 that is not fixed to the outer peripheral surface 14 of the inner shaft 10 between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 26 of the distal outer shaft 23 . . In the present embodiment, between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 26 of the distal outer shaft 23, the entire coil body 40 is a first coil body that is not fixed to the outer peripheral surface 14 of the inner shaft 10. It constitutes an intermediate portion 41 . That is, the coil body 40 has the first intermediate portion 41 over the entire length of the distal outer shaft 23 . In addition, in the present embodiment, the first intermediate portion 41 is separated from the outer peripheral surface 14 of the inner shaft 10 .

In addition, the coil body 40 is not fixed to the outer peripheral surface 14 of the inner shaft 10 between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 36 of the balloon 30 (that is, the internal space S3 of the balloon 30). 2 intermediate portions 42 . In this embodiment, between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 36 of the balloon 30 , the entire coil body 40 except for the tip end is not fixed to the outer peripheral surface 14 of the inner shaft 10 . An intermediate portion 42 is constructed. That is, the coil body 40 has the second intermediate portion 42 over the entire length of the internal space S3 of the balloon 30 .

A-3. How to use the balloon catheter 100:
The operator manipulates the proximal end of the balloon catheter 100 with the balloon 30 deflated, and moves the balloon catheter 100 to the affected area in the body cavity under the guidance of a guide wire (not shown). Next, by supplying fluid from the expansion fluid port 64 of the Y connector 60 to the internal space S3 of the balloon 30 through the expansion fluid lumen S2, the balloon 30 is expanded, and the expanded balloon 30 spreads the lesion.

Also, when moving the balloon catheter 100, for example, if the distal end of the balloon catheter 100 is caught in a relatively hard lesion and the balloon catheter 100 cannot be advanced any further, the operator should move the base of the balloon catheter 100. The end portion (the base end portion of the outer shaft 20 in this embodiment) is rotated around the axial direction. When the outer shaft 20 rotates in the axial direction, the rotational force is transmitted to the balloon 30 fixed to the distal end of the outer shaft 20 . Since the distal end portion of the balloon 30 is fixed to the distal end portion of the inner shaft 10 , the rotational force transmitted to the balloon 30 is transmitted to the distal end portion of the inner shaft 10 . However, since the balloon 30 is very flexible, it is not highly transmissible through such pathways. On the other hand, in the balloon catheter 100 of the present embodiment, the coil body 40 is fixed to the outer shaft 20 (more specifically, the distal end portion of the proximal outer shaft 27). Therefore, when the outer shaft 20 rotates in the axial direction, the rotational force is also transmitted to the coil body 40 fixed to the outer shaft 20 . Since the tip of the coil body 40 is fixed to the tip of the inner shaft 10 , the rotational force transmitted to the coil body 40 is transmitted to the tip of the inner shaft 10 . Since such a rotational force transmission path is a path that does not pass through the balloon 30, the rotational force transmissibility through this path is high. Therefore, the orientation of the distal end of the balloon catheter 100 is changed by the rotational force transmitted to the distal end of the inner shaft 10 through the path, and the catching is eliminated, so that the balloon catheter 100 can be advanced smoothly.

A-4. Effect of the first embodiment:
As described above, the balloon catheter 100 of this embodiment includes the balloon 30 , the tubular inner shaft 10 , the tubular outer shaft 20 and the coil body 40 . A proximal end of a balloon 30 is fixed to the distal end of the outer shaft 20 . The inner shaft 10 is housed in the hollow portions of the balloon 30 and the outer shaft 20 . A distal end portion of a balloon 30 is fixed to the distal end portion of the inner shaft 10 . The coil body 40 is arranged in a space formed between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 26 of the outer shaft 20 . A distal end portion of the coil body 40 is fixed to the inner shaft 10 , and a proximal end portion of the coil body 40 is fixed to the outer shaft 20 . The coil body 40 is arranged apart from the inner peripheral surface 26 of the outer shaft 20 . The coil body 40 also has a first intermediate portion 41 that is not fixed to the outer peripheral surface 14 of the inner shaft 10 between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 26 of the outer shaft 20 .

As described above, the balloon catheter 100 of this embodiment includes the coil body 40 having the distal end fixed to the inner shaft 10 and the proximal end fixed to the outer shaft 20 . The coil body 40 is spaced apart from the inner peripheral surface 26 of the outer shaft 20 , and is located between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 26 of the outer shaft 20 . It has a first intermediate portion 41 that is not fixed to surface 14 . Therefore, the first intermediate portion 41 of the coil body 40 can deform independently of the outer shaft 20 and the inner shaft 10 . Therefore, in the balloon catheter 100 of the present embodiment, the rotation of the proximal end of the balloon catheter 100 (the proximal end of the outer shaft 20 ) is effectively caused by the inner shaft 10 due to the presence of the first intermediate portion 41 of the coil body 40 . The torque can be transmitted, and the rotational force transmissibility of the balloon catheter 100 can be improved. In addition, since the coil body 40 is spaced apart from the inner peripheral surface 26 of the outer shaft 20, even if the outer shaft 20 is bent and pressed against the inner wall of the blood vessel and becomes difficult to move, the outer shaft 20 will not move. The restraint of the coil body 40 by the shaft 20 is suppressed, the deformation of the coil body 40 is prevented from being hindered by the outer shaft 20, and the rotational force transmissibility of the balloon catheter 100 can be effectively improved. .

Further, in the balloon catheter 100 of the present embodiment, the outer shaft 20 is connected to the distal end side outer shaft 23 to which the proximal end portion of the balloon 30 is fixed at the distal end portion, and to the proximal end portion of the distal end side outer shaft 23 to form a hypo. It has a base end side outer shaft 27 configured by a tube. A proximal end portion of the coil body 40 is fixed to a distal end portion of the proximal-side outer shaft 27 . As described above, in the balloon catheter 100 of the present embodiment, the proximal end of the coil body 40 is fixed to the distal end of the proximal-side outer shaft 27 made of a hypotube. 20 can be easily improved, and the presence of the first intermediate portion 41 of the coil body 40 can effectively improve the rotational force transmissibility of the balloon catheter 100 . In the present embodiment, since the proximal-side outer shaft 27 is made of metal, the joint strength between the coil body 40 and the outer shaft 20 can be further easily improved. The presence of one intermediate portion 41 can further effectively improve the rotational force transmissibility of the balloon catheter 100 .

Moreover, in the balloon catheter 100 of the present embodiment, the coil body 40 has the first intermediate portion 41 over the entire length of the distal outer shaft 23 . Therefore, according to the balloon catheter 100 of the present embodiment, in the coil body 40, the length of the first intermediate portion 41 that can be deformed independently of the outer shaft 20 and the inner shaft 10 can be sufficiently ensured. It is possible to effectively improve the rotational force transmissibility of the balloon catheter 100 .

Moreover, in the balloon catheter 100 of the present embodiment, the distal end portion of the coil body 40 is fixed to the distal end portion of the inner shaft 10 . Therefore, according to the balloon catheter 100 of the present embodiment, the rotation of the proximal end portion of the balloon catheter 100 (the proximal end portion of the outer shaft 20) can be effectively transmitted to the distal end portion of the inner shaft 10 by the coil body 40. It is possible to effectively improve the rotational force transmissibility of the balloon catheter 100 .

Further, in the balloon catheter 100 of the present embodiment, the coil body 40 is a second coil body that is not fixed to the outer peripheral surface 14 of the inner shaft 10 between the outer peripheral surface 14 of the inner shaft 10 and the inner peripheral surface 36 of the balloon 30 . has an intermediate portion 42 of . The second intermediate portion 42 of the coiled body 40 can deform independently from the inner shaft 10 and the balloon 30 . Therefore, according to the balloon catheter 100 of the present embodiment, the rotation of the proximal end of the balloon catheter 100 (the proximal end of the outer shaft 20 ) is further controlled by the inner shaft 10 due to the presence of the second intermediate portion 42 of the coil body 40 . The torque can be effectively transmitted, and the rotational force transmissibility of the balloon catheter 100 can be effectively improved. In addition, in the balloon catheter 100 of the present embodiment, the coil body 40 has the second intermediate portion 42 over the entire length of the internal space S3 of the balloon 30. A sufficient length of the second intermediate portion 42 that can be deformed independently can be ensured, and the rotational force transmissibility of the balloon catheter 100 can be effectively improved.

In addition, in the balloon catheter 100 of the present embodiment, the coil body 40 has a structure in which a plurality of wires 44 are spirally wound. Therefore, according to the balloon catheter 100 of the present embodiment, the rotation of the proximal end portion of the balloon catheter 100 (the proximal end portion of the outer shaft 20) can be more effectively transmitted to the inner shaft 10 due to the presence of the coil body 40. It is possible to further effectively improve the rotational force transmissibility of the balloon catheter 100 .

Further, in the balloon catheter 100 of the present embodiment, the coil body 40 is a loosely wound coil body. Therefore, according to the balloon catheter 100 of the present embodiment, the ease of deformation of the coil body 40 can be improved. can be more effectively transmitted to the inner shaft 10, and the rotational force transmissibility of the balloon catheter 100 can be more effectively improved. Further, according to the balloon catheter 100 of the present embodiment, even if the coil body 40 is arranged in the inflation fluid lumen S2, it is possible to effectively prevent the coil body 40 from obstructing the flow of the inflation fluid.

Moreover, in the balloon catheter 100 of the present embodiment, the wire 44 forming the coil body 40 is composed of a single wire. Therefore, according to the balloon catheter 100 of the present embodiment, simplification of the configuration and facilitation of manufacturing can be achieved.

Further, in the balloon catheter 100 of this embodiment, the inner shaft 10 has a shaft body 11 and a tip 12 provided at the distal end of the shaft body 11 . Therefore, according to the balloon catheter 100 of the present embodiment, it is possible to improve the rotational force transmissibility of the balloon catheter 100 while improving the flexibility of the distal end portion of the balloon catheter 100 .

B. Second embodiment:
FIG. 2 is an explanatory diagram schematically showing the configuration of the balloon catheter 100a in the second embodiment. In the following, among the configurations of the balloon catheter 100a of the second embodiment, the same configurations as those of the balloon catheter 100 of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the balloon catheter 100a of the second embodiment, the number of turns per unit length of the base end portion of the coil body 40a is greater than that of the other portions. As a result, the balloon catheter 100a has a first portion 110 and a second portion 120 with different rigidity on the distal side of the proximal outer shaft 27. As shown in FIG. The first portion 110 is a portion of the balloon catheter 100a that includes a portion having a relatively large number of turns per unit length in the coil body 40a. The second portion 120 is a portion of the balloon catheter 100a that includes a portion in which the coil body 40a has a relatively small number of turns per unit length. The second portion 120 is located distal to the first portion 110 and proximal to the balloon 30 and has a lower stiffness than the first portion 110 .

Thus, the balloon catheter 100 a of the second embodiment has a first portion 110 positioned distally of the proximal outer shaft 27 and a distal portion of the first portion 110 positioned distally of the balloon 30 . and a second portion 120 positioned on the side and less rigid than the first portion 110 . Therefore, in the balloon catheter 100a of the second embodiment, the rigidity of the balloon catheter 100a on the distal side of the proximal outer shaft 27 can be gradually changed so that the rigidity decreases toward the distal side. Therefore, according to the balloon catheter 100a of the second embodiment, the rigidity gap of the balloon catheter 100a caused by the outer shaft 20 being composed of the distal outer shaft 23 and the proximal outer shaft 27 is alleviated. can do.

In the balloon catheter 100a of the second embodiment, the number of turns per unit length of the coil body 40a in the first portion 110 is greater than the number of turns per unit length of the coil body 40a in the second portion 120. . Therefore, according to the balloon catheter 100a of the second embodiment, it is possible to reduce the rigidity gap of the balloon catheter 100a while suppressing an increase in the number of parts.

C. Third embodiment:
FIG. 3 is an explanatory diagram schematically showing the configuration of a balloon catheter 100b according to the third embodiment. In the following, among the configurations of the balloon catheter 100b of the third embodiment, the same configurations as those of the balloon catheter 100 of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

A balloon catheter 100b of the third embodiment comprises a core wire 80. As shown in FIG. The core wire 80 is made of metal, for example. The proximal end of the core wire 80 is fixed to the distal end of the proximal outer shaft 27 by welding, for example. The core wire 80 extends from the portion fixed to the proximal outer shaft 27 to the distal side along the axial direction of the distal outer shaft 23 to a position closer to the proximal side than the proximal end of the balloon 30 . In this embodiment, core wire 80 is positioned in expansion fluid lumen S2.

A balloon catheter 100b of the third embodiment has a first portion 110 and a second portion 120 having different rigidity on the distal side of the proximal outer shaft 27. As shown in FIG. The first portion 110 is the portion of the balloon catheter 100b that includes the core wire 80 . The second portion 120 is that portion of the balloon catheter 100b that does not include the core wire 80 . The second portion 120 is located distal to the first portion 110 and proximal to the balloon 30 and is less rigid than the first portion 110 .

As described above, the balloon catheter 100b of the third embodiment includes the first portion 110 positioned distally from the proximal outer shaft 27 and the distal portion distally from the first portion 110 and proximally from the balloon 30. and a second portion 120 positioned on the side and less rigid than the first portion 110 . Therefore, in the balloon catheter 100b of the third embodiment, the rigidity of the balloon catheter 100b on the distal side of the proximal outer shaft 27 can be gradually changed so that the rigidity decreases toward the distal side. Therefore, according to the balloon catheter 100b of the third embodiment, the stiffness gap of the balloon catheter 100b caused by the outer shaft 20 being composed of the distal outer shaft 23 and the proximal outer shaft 27 is alleviated. can do.

In addition, in the balloon catheter 100b of the third embodiment, the presence of the core wire 80 forms the first portion 110 and the second portion 120 having different rigidity. Therefore, according to the balloon catheter 100b of the third embodiment, the rigidity gap of the balloon catheter 100b is relaxed even when the coil body 40 having a simple configuration in which the number of turns per unit length is substantially constant is used. can be realized.

D. Fourth embodiment:
FIG. 4 is an explanatory diagram schematically showing the configuration of a balloon catheter 100c according to the fourth embodiment. In the following, among the configurations of the balloon catheter 100c of the fourth embodiment, the same configurations as those of the balloon catheter 100 of the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

In the balloon catheter 100c of the fourth embodiment, the distal end portion of the coil body 40c is fixed not to the distal end portion of the inner shaft 10 but to a position radially aligned with the proximal end portion of the balloon 30 on the inner shaft 10 . That is, in the balloon catheter 100c of the fourth embodiment, the coil body 40c is not arranged inside the internal space S3 of the balloon 30. As shown in FIG.

As described above, in the balloon catheter 100c of the fourth embodiment, since the coil body 40c is not arranged in the internal space S3 of the balloon 30, the presence of the coil body 40c increases the outer diameter of the deflated balloon 30. It is possible to avoid this phenomenon and improve the passageability of the balloon catheter 100c.

In addition, in the balloon catheter 100c of the fourth embodiment, it is preferable to improve the torsional rigidity of the inner shaft 10 by, for example, selecting the material for the inner shaft 10 and using a reinforcing member such as a braid. With this configuration, even if the distal end portion of the coil body 40c is fixed to the portion of the inner shaft 10 that is joined to the proximal end portion of the balloon 30, the presence of the coil body 40c allows the coil body 40c to be attached to the outer shaft 20. The resulting rotational force can be effectively transmitted to the distal end portion of the balloon catheter 100c, and the rotational force transmissibility of the balloon catheter 100c can be effectively improved.

E. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the scope of the invention. For example, the following modifications are possible.

The configuration of the balloon catheter 100 in the above embodiment is merely an example, and various modifications are possible. For example, in the above-described embodiment, the tip-side outer shaft 23 of the outer shaft 20 is composed of the small-diameter portion 21 and the large-diameter portion 22 having different diameters. It may have other portions with different diameters, or the tip-side outer shaft 23 may have the same diameter over its entire length. Further, in the above embodiment, the outer shaft 20 is composed of the distal outer shaft 23 and the proximal outer shaft 27, but the outer shaft 20 may have other parts in addition to them. Alternatively, the outer shaft 20 may be an integral member.

In the above embodiment, the inner shaft 10 is composed of the shaft main body 11 and the tip 12, but the inner shaft 10 may have other parts in addition to them, or the inner shaft 10 may be integrated. It may be a member.

In the above-described embodiment, the distal end portion of the coil body 40 is fixed at the distal end portion of the inner shaft 10 or at a position aligned with the proximal end portion of the balloon 30 on the inner shaft 10 . The position is not limited to this. For example, the distal end portion of the coil body 40 is located at an intermediate position between the distal end portion of the inner shaft 10 and the position aligned with the proximal end portion of the balloon 30 on the inner shaft 10 (that is, the position facing the internal space S3 of the balloon 30). ), or may be fixed at a position closer to the proximal end than the position aligned with the proximal end portion of the balloon 30 on the inner shaft 10 . In addition, in the above-described embodiment, the proximal end of the coil body 40 is fixed to the distal end of the proximal-side outer shaft 27, but the fixed position of the proximal end of the coil body 40 is not limited to this. For example, the proximal end of the coil body 40 may be fixed to a portion other than the distal end of the proximal outer shaft 27 or may be fixed to the distal outer shaft 23 . Even with such a configuration, the rotation of the proximal end of the balloon catheter 100 (the proximal end of the outer shaft 20) can be effectively transmitted to the inner shaft 10 due to the presence of the coil body 40, and the balloon catheter 100 can effectively improve the rotational force transmissibility of the Also, the proximal end portion of the coil body 40 may be fixed to the inner shaft 10 . Even with such a configuration, the presence of the coil body 40 can effectively transmit the rotation of the proximal end portion of the balloon catheter 100 (the proximal end portion of the inner shaft 10) to the distal end portion of the inner shaft 10. The rotational force transmissibility of the balloon catheter 100 can be effectively improved.

In the above-described embodiment, the coil body 40 has the first intermediate portion 41 over the entire length of the distal outer shaft 23 , but the coil body 40 extends over only part of the entire length of the distal outer shaft 23 . may have an intermediate portion 41 of In addition, in the first to third embodiments, the coil body 40 has the second intermediate portion 42 over the entire length of the internal space S3 of the balloon 30. It is also possible to have the second intermediate portion 42 over only a portion of the total length. Alternatively, the coil body 40 may not have the second intermediate portion 42 .

In the above-described embodiment, the coil body 40 has a structure in which the wire rod 46 composed of three wires 44 each composed of a single wire is loosely wound spirally. Not limited. For example, the coil body 40 may have a structure in which a wire rod 46 composed of two or four or more wires 44 each composed of a single wire is loosely wound spirally. Note that the cross-sectional shape of the wire 44 perpendicular to the axial direction is not limited to a rectangle, and may be a square, a circle, an ellipse, or another shape.

Alternatively, the coil body 40 may have a structure in which a single wire 44 is spirally loosely wound. With such a configuration, the ease of deformation of the coil body 40 can be improved, and the presence of the coil body 40 can more effectively transmit the rotation of the outer shaft 20 to the inner shaft 10, and the balloon can be rotated. The rotational force transmissibility of the catheter 100 can be further effectively improved. Further, with such a configuration, even if the coil body 40 is arranged in the expansion fluid lumen S2, it is possible to effectively suppress the obstruction of the flow of the expansion fluid by the coil body 40 .

Moreover, each wire 44 that constitutes the coil body 40 may be composed of a twisted wire obtained by twisting a plurality of strands. With such a configuration, the durability of the coil body 40 can be improved, and thus the durability of the balloon catheter 100 can be improved.

Also, the coil body 40 may be wound tightly. With such a configuration, the durability of the coil body 40 can be improved, and thus the durability of the balloon catheter 100 can be improved.

Also, as the coil body 40, a two-layer coil (the inner layer and the outer layer are not woven together) in which two coils having different winding directions are laminated may be used. With such a configuration, it is possible to improve the rotational force transmissibility with respect to rotation of the balloon catheter 100 in both directions around its axis.

In the second embodiment, the core wire 80 is arranged in the expansion fluid lumen S2, but the core wire 80 is arranged in another lumen formed in the outer shaft 20 (for example, a dedicated lumen provided for the core wire 80). may have been

10: Inner shaft 11: Shaft main body 12: Tip 14: Outer peripheral surface 20: Outer shaft 21: Small diameter portion 22: Large diameter portion 23: Distal side outer shaft 26: Inner peripheral surface 27: Base side outer shaft 30: Balloon 36: inner peripheral surface 40: coil body 41: first intermediate portion 42: second intermediate portion 44: wire 46: wire rod 60: Y connector 62: guide wire port 64: expansion fluid port 70: protective tube 80: core wire 100: Balloon Catheter 110: First Section 120: Second Section S1: Guidewire Lumen S2: Expansion Fluid Lumen S3: Interior Space

Claims (18)

a balloon catheter,
a balloon;
a cylindrical outer shaft to which the proximal end of the balloon is fixed to the distal end;
a cylindrical inner shaft housed in a hollow portion of the balloon and the outer shaft and having a distal end portion of the balloon fixed to the distal end portion;
Disposed in the space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft, the distal end portion is fixed to the inner shaft, and the base end portion is attached to the outer shaft or the inner shaft. a fixed coil body;
with
The coil body is spaced apart from the inner peripheral surface of the outer shaft,
The coil body has a first intermediate portion, which is not fixed to the outer peripheral surface of the inner shaft, between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft.
balloon catheter. A balloon catheter according to claim 1, wherein
The outer shaft is
a distal outer shaft having a proximal end portion of the balloon fixed to the distal end portion;
a proximal-side outer shaft connected to the proximal end of the distal-side outer shaft;
has
The proximal end of the coil body is fixed to the distal end of the proximal outer shaft,
balloon catheter. A balloon catheter according to claim 2, wherein
The proximal outer shaft is made of metal,
balloon catheter. The balloon catheter according to claim 2 or 3,
The coil body has the first intermediate portion over the entire length of the tip-side outer shaft,
balloon catheter. A balloon catheter according to any one of claims 2 to 4,
a first portion located on the distal side of the proximal outer shaft;
a second portion located distal to the first portion and proximal to the balloon and having a lower rigidity than the first portion;
balloon catheter. A balloon catheter according to claim 5, wherein
the number of turns per unit length of the coiled body in the first portion is greater than the number of turns per unit length of the coiled body in the second portion;
balloon catheter. The balloon catheter of claim 5, further comprising:
a core wire disposed in the first portion, having a proximal end fixed to a distal end of the proximal-side outer shaft, and extending along the axial direction of the distal-side outer shaft;
balloon catheter. A balloon catheter according to any one of claims 1 to 7,
The tip of the coil body is fixed to the tip of the inner shaft,
balloon catheter. A balloon catheter according to claim 8, wherein
The coil body has a second intermediate portion, which is not fixed to the outer peripheral surface of the inner shaft, between the outer peripheral surface of the inner shaft and the inner peripheral surface of the balloon,
balloon catheter. A balloon catheter according to claim 9, wherein
The coil body has the second intermediate portion over the entire length of the interior space of the balloon,
balloon catheter. A balloon catheter according to any one of claims 1 to 7,
The distal end portion of the coil body is fixed at a position on the inner shaft that is aligned with the proximal end portion of the balloon or at a position on the proximal side of the position.
balloon catheter. A balloon catheter according to any one of claims 1 to 11,
The coil body has a structure in which a single wire is spirally wound,
balloon catheter. A balloon catheter according to any one of claims 1 to 11,
The coil body has a structure in which a plurality of wires are spirally wound,
balloon catheter. A balloon catheter according to claim 12 or claim 13,
The coil body is a loosely wound coil body,
balloon catheter. A balloon catheter according to claim 12 or claim 13,
The coil body is a tightly wound coil body,
balloon catheter. A balloon catheter according to any one of claims 12 to 15,
The wire is composed of a single strand,
balloon catheter. A balloon catheter according to any one of claims 12 to 15,
The wire is composed of a stranded wire in which a plurality of strands are twisted together,
balloon catheter. A balloon catheter according to any one of claims 1 to 17,
The inner shaft has a shaft body and a tip provided at the tip of the shaft body,
balloon catheter.

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