JP2012223207A - Balloon catheter - Google Patents

Abstract

【Task】
An object of the present invention is to provide a balloon catheter having a high kink resistance that can ensure a desired rigidity in both the axial direction and the circumferential direction of the outer shaft.
[Solution]
The balloon catheter 10 is provided with at least a part of the balloon 20 and a tubular outer shaft 30 constituting an expansion lumen for supplying a fluid for expanding the balloon 20, and at least a part of the balloon catheter 10 is disposed inside the outer shaft 30. In addition, a tubular inner shaft 50 for inserting a guide wire and a linear member extending in the axial direction in the outer shaft 30 and arranged at a predetermined interval, at least one of which is different from the others. First, second, and third core wires 81, 82, and 83 are provided.
[Selection] Figure 1

Description

  The present invention relates to a balloon catheter used for dilating a stenosis in a body cavity such as a blood vessel.

  Conventionally, a balloon catheter is used to dilate a stenosis portion in a body cavity such as a blood vessel. The balloon catheter is mainly composed of a balloon as an expansion body, an outer shaft, and an inner shaft arranged inside the balloon. The inner shaft is for inserting a guide wire, and the outer shaft is for circulating a liquid such as a contrast medium or physiological saline for expanding the balloon through an expansion lumen provided between the inner shaft and the inner shaft. belongs to.

  Such a balloon catheter needs to be adjusted in rigidity so as to be flexible toward the tip. Further, in order to improve kink resistance, which is a property that the outer shaft is not easily crushed or twisted when an external force or the like is applied, the outer shaft needs to have rigidity in the circumferential direction.

  Conventionally, in order to change the rigidity of the balloon catheter in the axial direction, there is one having a core wire in the outer shaft (for example, see Patent Documents 1 to 5 below).

JP 2002-291899 A Japanese translation of PCT publication No. 2002-505166 Special table 2003-517901 gazette Japanese National Patent Publication No. 8-500505 Japanese National Patent Publication No. 9-503411

  In the balloon catheter provided with the above core wire, although there is a certain effect in adjusting the axial rigidity of the outer shaft, it is not sufficient to improve the rigidity of the outer shaft in the circumferential direction. There is a demand for further improvement.

  The present invention has been made in view of such circumstances, and a balloon catheter having high kink resistance that can secure desired rigidity in both the axial direction and the circumferential direction of the outer shaft. The purpose is to provide.

  In the present invention, the above problems are solved by the means listed below.

<1> A balloon, a tubular outer shaft that is attached to at least a part of the balloon and forms an expansion lumen that supplies a fluid for expanding the balloon, and at least a part of the balloon is disposed inside the outer shaft. In addition, a tubular inner shaft for inserting a guide wire and a linear member extending in the axial direction within the outer shaft and arranged at a predetermined interval, at least one of which is different from the others. A balloon catheter comprising: a core wire.

<2> The balloon catheter according to aspect 1, wherein the number of the core wires is at least three and the interval between the adjacent core wires is different from each other.

<3> A guide wire port formed by connecting a rear end of the inner shaft is connected to a side of the outer shaft, and at least one of the plurality of core wires is the outer shaft. Aspect 1 or 2, wherein the distal end portion extends from the rear end side of the outer shaft to the distal end side beyond the guide wire port while being disposed on the opposite side to the guide wire port with respect to the central axis. 2. The balloon catheter according to 2.

<4> The aspect according to any one of aspects 1 to 3, wherein at least one tip portion of the plurality of core wires is fixed to at least one of the outer shaft and the inner shaft. Balloon catheter.

<5> The balloon catheter according to any one of aspects 1 to 4, wherein at least one of the plurality of core wires is a stranded wire formed by twisting a plurality of strands.

<1> Since the balloon catheter of the present invention is provided with a plurality of core wires arranged at predetermined intervals in the outer shaft, not only the axial direction but also circumferential rigidity is ensured. For this reason, the kink resistance of the balloon catheter is improved. Moreover, since each core wire consists of a linear member, even if it arranges multiple, it can prevent that a softness | flexibility deteriorates.

In the balloon catheter of the present invention, at least one of the plurality of core wires is different from the others. That is, at least one core wire is different from other core wires in at least one element such as length, thickness, shape, and material. For this reason, the balance of the balloon catheter can be improved while increasing the rigidity of the outer shaft in the circumferential direction in consideration of the positional relationship between the inner shaft and the core wire in the outer shaft. Further, the rigidity can be adjusted so that the balloon catheter can be easily bent in a desired direction.
Furthermore, since a plurality of core wires are provided, it is possible to improve the transmission of the pushing force by which an operator such as a doctor pushes the balloon catheter from the rear end side toward the front end side.

<2> In the second aspect of the present invention, not only at least one of the plurality of core wires is different from the other core wires, but also the number of core wires is at least three, and the interval between adjacent core wires is different from each other. It is supposed to be. Therefore, in more detail, it is possible to create a balloon catheter having a desired rigidity in both the axial direction and the circumferential direction in consideration of the balance with other members such as the inner shaft in the outer shaft. it can. Therefore, the operability of the balloon catheter is further improved. Further, the rigidity can be adjusted so that the balloon catheter can be easily bent in a desired direction.

<3> In the aspect 3 of the present invention, at least one of the plurality of core wires is disposed on the side opposite to the guide wire port with respect to the central axis of the outer shaft, and the front end portion is the rear end side of the outer shaft. Extends beyond the guide wire port to the distal end. For this reason, when the balloon catheter is operated with the guide wire inserted into the inner shaft, even if the inner shaft is biased toward the guide wire port by the guide wire, the inner shaft and the core wire are balanced and the operability is improved. Will improve.

<4> In aspect 4 of the present invention, at least one tip portion of the plurality of core wires is fixed to at least one of the outer shaft and the inner shaft. For this reason, not only can the rigidity in the circumferential direction of the outer shaft be increased, but also the transmission of the pushing force when the operator pushes the balloon catheter in the axial direction from the proximal side can be further enhanced.

<5> In aspect 5 of the present invention, at least one of the plurality of core wires is formed of a stranded wire formed by twisting a plurality of strands. For this reason, since the flexibility of the core wire can be increased, the kink resistance can be improved while maintaining the flexibility of the balloon catheter. That is, flexibility is improved as compared with the case of having a plurality of core wires made of one wire, and even when an external force acts on the outer shaft during use of the balloon catheter, the outer shaft can be prevented from being crushed or bent.

FIG. 1 is an overall view of a balloon catheter according to the present embodiment. FIG. 2 is a view as seen from the direction II-II in FIG. 3 is a view as seen from the direction of III-III in FIG. FIG. 4 is a diagram showing another embodiment. FIG. 5 is a diagram showing another embodiment relating to a combination of a plurality of core wires. FIG. 6 is a view showing still another embodiment relating to a combination of a plurality of core wires. FIG. 7 is a view showing another embodiment of the core wire.

  The balloon catheter of the present embodiment will be described with reference to FIGS. 1 and 3, the left side in the figure is the distal end side (distal side) inserted into the body, and the right side is the rear end side (proximal side, proximal end side) operated by an operator such as a doctor.

The balloon catheter 10 is used, for example, for treating a blockage or stenosis of a heart blood vessel, and has a total length of about 1500 mm.
The balloon catheter 10 mainly includes a balloon 20, an outer shaft 30, an inner shaft 50, a connector 60, and first, second, and third core wires 81, 82, and 83.

  The balloon 20 is a resin member, and has an expansion part 21 for expanding the balloon 20 in the center in the axial direction, a front end attachment part 22 on the front end side, and a rear end attachment part 23 on the rear end side.

The tip attachment portion 22 is fixed to the tip portion (including the tip 59) of the inner shaft 50.
The rear end mounting portion 23 is fixed to the outer peripheral surface of the front end portion of the outer shaft 30.

  The outer shaft 30 is a tubular member that forms an expansion lumen 36 for supplying a fluid for expanding the balloon 20. The outer shaft 30 includes a front end outer shaft portion 31 positioned on the front end side and a rear end outer shaft portion 37 positioned on the rear end side. The distal end outer shaft portion 31 is a resin tube. For example, polyamide, polyamide elastomer, polyolefin, polyester, polyester elastomer, or the like is used as the resin constituting the distal end outer shaft portion 31.

  A rear end attaching portion 23 of the balloon 20 is fixed to the outer periphery of the distal end of the distal end outer shaft portion 31. In the case of the present embodiment, the rear end mounting portion 23 is fixed to the outer peripheral surface of the front end of the front outer shaft portion 31, but may be fixed to the inner peripheral surface of the front end of the front outer shaft portion 31.

  The distal outer shaft portion 31 houses the inner shaft 50. The rear end of the inner shaft 50 is attached to the side surface of the front outer shaft portion 31, and a rear end side guide wire port 54 is formed in this attachment portion. A space between the distal outer shaft portion 31 and the inner shaft 50 is a distal expansion lumen 36 a that constitutes the distal end portion of the expansion lumen 36.

  First, second, and third core wires 81, 82, and 83, which will be described later, are inserted into the expansion lumen 36a.

  In the present embodiment, the outer diameter of the distal end outer shaft portion 31 is set to about 0.80 mm to about 0.95 mm, and is about 0.84 mm. In the present embodiment, the inner diameter of the distal outer shaft portion 31 is set to about 0.70 mm to about 0.85 mm, and is about 0.73 mm.

  The rear end outer shaft portion 37 is a metal tubular member called a so-called hypotube. The front end portion of the rear end outer shaft portion 37 is inserted and fixed to the rear end portion of the front end outer shaft portion 31. The rear end expansion lumen 36b formed inside the rear end outer shaft portion 37 constitutes the expansion lumen 36 together with the above-described front end expansion lumen 36a.

  A connector 60 is attached to the rear end of the rear end outer shaft portion 37. When liquid such as a contrast medium or physiological saline for expanding the balloon 20 is supplied from an indeflator (not shown) attached to the connector 60, the liquid expands the balloon 20 through the expansion lumen 36. ing.

  In the case of the present embodiment, the outer diameter of the rear end outer shaft portion 37 is set in a range of about 0.60 mm to about 0.70 mm, and is about 0.69 mm. The inner diameter is set in the range of about 0.45 mm to about 0.50 mm, and is about 0.48 mm. The material of the rear end outer shaft portion 37 is not particularly limited, but in the case of the present embodiment, stainless steel is used. As a material other than this, a superelastic alloy such as a Ni-Ti alloy is used.

  The inner shaft 50 is housed in the distal end outer shaft portion 31. The inner shaft 50 is a tubular member formed of the same resin as the distal outer shaft portion 31 and has a guide wire lumen 51 for inserting a guide wire therein.

  In the case of the present embodiment, the outer diameter of the inner shaft 50 is set in the range of about 0.50 mm to about 0.60 mm, and is about 0.53 mm. The inner diameter is set in a range of about 0.36 mm to about 0.45 mm, and is about 0.41 mm.

  A rear end side guide wire port 54 is formed by welding the rear end of the inner shaft 50 to the side surface of the front outer shaft portion 31.

The distal end of the inner shaft 50 has an extending portion 52 that extends from the distal end of the distal outer shaft portion 31. The extending part 52 has a tip 59 at the tip.
The chip 59 is a member having a tapered outer shape whose outer diameter gradually decreases toward the tip, and is formed of a flexible resin. The tip 59 is a cylindrical member that forms the distal end portion of the guide wire lumen 51, and has a distal end side guide wire port 53 at the distal end.

  The distal end mounting portion 22 of the balloon 20 is fixed to the distal end portion (including the tip 59) of the extending portion 52 of the inner shaft 50.

  A pair of radiopaque markers 70 spaced apart from each other by a predetermined distance are attached to a portion of the extended portion 52 of the inner shaft 50 positioned inside the expanded portion 21 of the balloon 20.

First, second, and third core wires 81, 82, and 83 are inserted into the distal end outer shaft portion 31. The first, second, and third core wires 81, 82, and 83 are linear members that have a circular cross-sectional shape and are reduced in diameter toward the tip. The front ends of the core wires 81, 82, 83 are free ends, and the rear ends are fixed to the front end portions of the rear end outer shaft portion 37. The first core wire 81 is different from the second and third core wires 82 and 83, and the second core wire 82 and the third core wire 83 are substantially the same. Specifically, the first, second, and third core wires 81, 82, and 83 are made of the same material, but the first core wire 81 is different in length and thickness from the second and third core wires 82 and 83. ing.
The number of core wires 81, 82, 83 is not limited to three, and a plurality of core wires is sufficient.

  The material of the first, second, and third core wires 81, 82, and 83 is not particularly limited, but in the case of the present embodiment, it is a metal wire. The type of metal is not particularly limited, but in the case of the present embodiment, stainless steel (SUS304) is used. As other materials, a super elastic alloy such as a Ni-Ti alloy, a piano wire, or the like is used. In addition to the metal, a resin wire can be used. In the present embodiment, the first, second, and third core wires 81, 82, and 83 are made of the same material, but different materials can be used for each core wire.

  As shown in FIG. 2, the first, second, and third core wires 81, 82, and 83 are arranged at an equal angle θ <b> 1 (= 120 °) with the central axis A of the outer shaft 30 as the center.

  The first core wire 81 is disposed between the second and third core wires 82 and 83 at a position facing the rear end side guide wire port 54 with respect to the central axis A of the outer shaft 30. The first core wire 81 is longer and thicker than the second and third core wires 82 and 83. The length of the first core wire 81 is set so as to extend to the front end side beyond the rear end side guide wire port 54, and is 190 mm in the present embodiment. In the case of the present embodiment, the diameter D1 of the first core wire 81 decreases from about 0.20 mm to about 0.10 mm in the distal direction.

  The second and third core wires 82 and 83 have the same length and thickness. The lengths of the second and third core wires 82 and 83 are set as long as possible within a range that does not exceed the rear end side guide wire port 54. In the present embodiment, the length is 115 mm. In the present embodiment, the diameters D2 and D3 of the second and third core wires 82 and 83 are both reduced from about 0.15 mm to about 0.08 mm in the distal direction.

  As described above, by arranging the first, second, and third core wires 81, 82, and 83, the rigidity is increased when the guide wire is inserted, and tends to be biased toward the rear end side guide wire port 54 side. A certain inner shaft 50 and a first core wire 81 arranged at a position facing the inner shaft 50 are balanced in the distal end outer shaft portion 31. In addition, the second and third core wires 82 and 83 are present behind the rear end side guide wire port 54 where the inner shaft 50 is not present, and the circumferential direction of the front outer shaft portion 31 is increased. It is designed to increase rigidity. As described above, the first, second, and third core wires 81, 82, and 83 are evenly arranged in the circumferential direction in consideration of the positional relationship with the inner shaft 50, so that the center of gravity of the balloon catheter 10 is stabilized. The operability is improved, and the kink resistance of the distal outer shaft portion 31 can be improved.

  The rear ends of the first, second, and third core wires 81, 82, and 83 are fixed to the front end portion of the rear end outer shaft portion 37 by brazing, welding by laser, or the like. As shown in FIG. 3, a rectangular cutout 90 is formed at the distal end of the rear outer shaft portion 37 to which the first, second, and third core wires 81, 82, and 83 are attached. With the rear ends of the first, second, and third core wires 81, 82, and 83 fitted in the notches 90, brazing, laser welding, or the like is performed. This not only facilitates the joining of the first, second and third core wires 81, 82 and 83 and the rear end outer shaft portion 37, but also the first, second and third core wires 81, 82 and 83. The rear end portion prevents the opening area of the rear end outer shaft portion 37 from being reduced.

In addition, as a method of ensuring the opening area of the rear end outer shaft portion 37, as described above, instead of forming the rectangular cutout portion 90 in the rear end outer shaft portion 37, the first, second, third The rear end portions of the core wires 81, 82, and 83 may be joined to the rear end outer shaft portion 37 as a thin wall by polishing.
Further, if the opening area of the rear outer shaft portion 37 can be secured even if a plurality of core wires are joined, the rear end of the core wire is directly processed without processing the rear end of the core wire or the front end portion of the rear outer shaft portion 37. The end may be joined to the front end portion of the rear end outer shaft portion 37.

  Based on the above configuration, a case will be described in which the balloon catheter 10 of the present embodiment is used for a procedure for expanding a stenosis in a coronary artery of the heart.

  When the operation of the balloon catheter 10 to the heart is started, a medical device such as a catheter called a sheath introducer (not shown) is inserted into the body in advance at a place where the balloon catheter 10 such as the wrist or thigh is inserted. An instrument for guiding is installed. Further, a guide wire (not shown) is inserted into the body through the sheath introducer, and the distal end of the guide wire reaches the coronary artery of the heart where the stenosis is the target of treatment. The balloon catheter 10 is inserted into the body along this guide wire. The rear end of the guide wire is inserted from the distal end side guide wire port 53 of the tip 59 of the balloon catheter 10, passes through the guide wire lumen 51 in the inner shaft 50, and extends from the rear end side guide wire port 54.

  When the balloon catheter 10 is pushed into the body along the guide wire, the distal outer shaft portion 31 may bend near the entrance of the sheath introducer. Even in such a case, since the first, second, and third core wires 81, 82, and 83 are disposed in the circumferential direction of the distal outer shaft portion 31, the circumferential rigidity of the distal outer shaft portion 31 is increased. Therefore, it is possible to prevent the distal end outer shaft portion 31 from being bent or crushed. That is, kink resistance can be improved.

  Further, when the balloon catheter 10 advances in the blood vessel, the axial force applied by the operator from the proximal side of the rear end outer shaft portion 37, that is, the pushing force is applied from the rear end outer shaft portion 37 to the front end. It is transmitted to the outer shaft portion 31.

  At the same time, the pushing force is transmitted from the rear end outer shaft portion 37 to the first, second, and third core wires 81, 82, and 83 attached to the rear end outer shaft portion 37. With the plurality of core wires 81, 82, 83, it is possible to improve the transferability of the pushing force.

  At this time, even when an external force is applied to the balloon catheter 10 such as when the balloon catheter 10 passes through a bent blood vessel or the like, the first, second, and third core wires 81, 82, and 83 are connected to the inner end of the distal outer shaft portion 31. Since the positional relationship with the shaft 50 is taken into consideration, the balance of the balloon catheter 10 is good. For this reason, the operability of the balloon catheter 10 is good, and the balloon catheter 10 can be favorably passed through a blood vessel or the like that bends.

  Further, since a plurality of core wires 81, 82, 83 are present in the circumferential direction of the distal outer shaft 31, the circumferential rigidity of the distal outer shaft 31 is increased, and a blood vessel or the like in which the distal outer shaft 31 is bent. It can be prevented from being crushed or bent by an external force that is received when passing through the door. That is, kink resistance can be improved.

  Under the fluoroscopy, the operator positions the balloon 20 at the stenosis, which is the target site, using the marker 70, and then expands liquid such as a contrast medium or physiological saline from an indeflator (not shown) connected to the connector 60. Is supplied. At this time, the expansion liquid flows into the expansion lumen 36 of the outer shaft 30. Then, the expansion liquid flows out from the distal end of the distal end outer shaft portion 31 of the outer shaft 30 to expand the balloon 20.

When the procedure for expanding the stenosis with the balloon 20 is completed, the operator discharges the expansion liquid from the balloon 20 by the inflator. That is, the expansion liquid flows out from the inside of the balloon 20 and is discharged from the front end expansion lumen 36a of the front end outer shaft portion 31 and the rear end expansion lumen 36b of the rear end outer shaft portion 37 to the inflator.
Thereafter, the balloon catheter 10 is pulled out of the body, and the procedure is completed.

  As described above, since the first, second, and third core wires 81, 82, and 83 are provided in the circumferential direction of the outer shaft 30, the balloon catheter 10 of the present embodiment is not only in the axial direction but also in the circumferential direction. Directional rigidity is also ensured. Moreover, since each core wire 81, 82, 83 consists of a wire, even if it arranges multiple, it can prevent that a softness | flexibility deteriorates.

  Furthermore, since the plurality of core wires 81, 82, and 83 are provided, it is possible to improve the transmission of the pushing force. Further, the first, second, and third core wires 81, 82, and 83 are determined in length, thickness, material, shape, and the like in consideration of the positional relationship with the inner shaft 50 in the distal end outer shaft portion 31. And is arranged. That is, the first core wire 81 is disposed on the opposite side to the central axis A of the inner shaft 50 and the outer shaft 30 into which the guide wire is inserted. The second and third core wires 82 and 83 are disposed on the same side with respect to the inner shaft 50 and the central axis A on the rear side from the rear end side guide wire port 54 where the inner shaft 50 does not exist. With such a configuration, the balance of the balloon catheter 10 during the procedure is improved, and the operability is improved.

  In the embodiment described above, the first, second, and third core wires 81, 82, and 83 all have free ends. However, as shown in FIG. 4, the tip of at least one core wire may be fixed to at least one of the outer shaft 30 and the inner shaft 50. In the example of FIG. 4, the case where the front-end | tip part of the 1st core wire 81 is welded and fixed to both the front-end | tip outer shaft part 31 and the inner shaft 50 by the junction part 100 is shown. By adopting such a configuration, not only can the rigidity in the circumferential direction of the outer shaft 30 be increased, but also the ability to transmit the pushing force when the operator pushes the balloon catheter 10 in the axial direction from the proximal side. It can be further enhanced. In particular, in this case, since the first core wire 81 is fixed to the inner shaft 50, the pushing force can be transmitted to the tip 59 which is the tip of the inner shaft 50.

  In the embodiment described above, the first, second, and third core wires 81, 82, 83 are arranged at equal intervals in the circumferential direction so as to equally divide the periphery of the rear end outer shaft portion 37. . That is, the first, second, and third core wires 81, 82, and 83 are arranged at 120 ° intervals. Such an arrangement is effective in stabilizing the operability of the balloon catheter 10 because the first, second, and third core wires 81, 82, and 83 are arranged in a balanced manner in the distal outer shaft portion 31. In particular, in the case of the above-described embodiment, since the longest first core wire 81 is disposed at a position facing the rear end side guide wire port 54, the inner shaft 50 and the first core wire 81 are connected to the distal end outer shaft portion 31. Since the balance is maintained in the inside, the operability of the balloon catheter 10 is improved.

  However, the arrangement of the plurality of core wires is not limited to this, and various modes can be adopted. For example, in the embodiment of FIG. 5, the two core wires 181 and 182 are arranged on the opposite side of the rear end side guide wire port 54 with respect to the central axis A of the outer shaft 30 and the rear end side guide wire port 54 is arranged. The angle θ2 formed by the two core wires 181 and 182 is equally 120 °. Further, the diameter of the core wire 181 is made larger than the diameter of the core wire 182. In such a case, the distal end outer shaft portion 31 can have a tendency to bend in a certain direction.

  In addition, as shown in FIG. 6, the three core wires 281, 282, and 283 have different thicknesses, and the core wires 281, 282, and 283 have different angles θ 3 and θ 4 with respect to the central axis A of the outer shaft 30. , Θ5 may be arranged. Since the plurality of core wires are arranged at different distances in the circumferential direction of the rear end outer shaft portion 37 in this manner, the circumferential rigidity of the balloon catheter 10 can be changed. 10 can be manufactured. For example, as described above, when the distal end portion of one core wire is welded to form the joint portion 100, or when the deviation of the center of gravity occurs in the distal end outer shaft portion 31, a plurality of core wires are thus connected. It is effective to arrange them at different angles with respect to the central axis A.

  4 to 6, the substantially same configuration as that of the embodiment shown in FIGS. 1 to 3 is denoted by the same reference numeral.

  As described above, as a method for making at least one core wire different from other core wires among a plurality of core wires, there is a method of changing the length, thickness and material of the core wire. In addition, the shape of the core wire may be different from the shape of other core wires. For example, each of the first, second, and third core wires 81, 82, and 83 has a shape that is reduced in diameter toward the tip, but one core wire is made of a wire having a constant diameter. You may do it.

  Further, the cross-sectional shape of the core wire is not limited to a round shape as described above, but can take various forms such as a rectangle, a square, and an oval.

  Furthermore, in the above-described embodiment, the first, second, and third core wires 81, 82, and 83 are each composed of one wire. However, as shown in FIG. 7, you may comprise from the strand wire which put together the some strand. In the example of FIG. 7, one core wire 380 shown in FIG. 7 (a) is composed of three strands 380a as shown in the cross-sectional view of FIG. 7 (b). Thus, by comprising a core wire from a strand wire, kink resistance can be improved, maintaining a softness | flexibility. That is, the flexibility is improved as compared with the case of having a plurality of core wires made of one wire, and the distal outer shaft portion 31 is crushed even if an external force acts on the distal outer shaft portion 31 when the balloon catheter 10 is used. , Can prevent bending.

  In the embodiment described above, the balloon catheter 10 is used for treatment of the blood vessels of the heart, but can be used for various procedures such as a procedure for expanding the blood vessels of the lower limbs and the shunt for dialysis.

DESCRIPTION OF SYMBOLS 10 Balloon catheter 20 Balloon 30 Outer shaft 31 Front end outer shaft part 36 Expansion lumen 37 Rear end outer shaft part 50 Inner shaft 51 Guide wire lumen 54 Rear end side guide wire port 81 First core wire 82 Second core wire 83 Third core wire 380 Core wire 380a Wire

Claims (5)

With balloons,
A tubular outer shaft which is attached to at least a part of the balloon and forms an expansion lumen for supplying a fluid for expanding the balloon;
A tubular inner shaft for inserting a guide wire, at least part of which is disposed inside the outer shaft;
A balloon catheter comprising: a plurality of core wires extending in the axial direction within the outer shaft and arranged at predetermined intervals, at least one of which is different from the other core wires. The plurality of core wires is at least three;
The balloon catheter according to claim 1, wherein an interval between the adjacent core wires is different from each other. On the side of the outer shaft, it has a guide wire port formed by connecting the rear end of the inner shaft,
At least one of the plurality of core wires is disposed on the side opposite to the guide wire port with respect to the central axis of the outer shaft, and a tip portion of the core wire extends from the rear end side of the outer shaft to the guide wire port. The balloon catheter according to claim 1, wherein the balloon catheter extends beyond the distal end.   4. The balloon catheter according to claim 1, wherein at least one distal end portion of the plurality of core wires is fixed to at least one of the outer shaft and the inner shaft. 5. .   The balloon catheter according to any one of claims 1 to 4, wherein at least one of the plurality of core wires is a stranded wire formed by twisting a plurality of strands.

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