JP2012152353A - Balloon catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter sufficiently transmitting a push-in force applied from a proximal side of the balloon catheter to a distal side of the balloon catheter, and preventing that a kink or the like occurs when pulling a balloon outside a body.SOLUTION: This balloon catheter 10 includes: an intermediate outer shaft part 35 connecting a front end outer shaft part 31 and a rear end outer shaft part 37, and having a yield point lower than the front end outer shaft part 31 and the rear end outer shaft part 37; an engagement part 33 provided in the front end outer shaft part 31; and a press member 70 having a rear end side joined to the rear end shaft 37 and inserted through the intermediate outer shaft part 35, and having an abutment face 70a capable of abutting on the engagement part 33 at the front end.

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 a lumen provided between the inner shaft and the inner shaft. Is.

Since such a balloon catheter is inserted into a blood vessel or the like and positioned at a desired position, a force such as a doctor or the like is applied to push the catheter from the proximal side toward the distal end. The balloon catheter is required to have a high force for pushing the catheter in the axial direction, that is, a so-called push force transmission property, that is, a push property is high.
Conventionally, in order to improve indentation characteristics, there is one in which a tubular member is inserted into the outer shaft of a balloon (see, for example, Patent Document 1 below).

  Some have a core wire in the outer shaft in order to improve the push-in characteristics and adjust the change in rigidity of the balloon catheter. Some balloon catheters having such a core wire have a distal end portion of the core wire fixed to a part of the catheter in order to further improve the push-in characteristics (see, for example, Patent Documents 2, 3, and 4 below). ).

JP-T-2005-110721 gazette JP 2008-1225897 A Japanese National Patent Publication No. 8-500505 Japanese National Patent Publication No. 9-503411

  The balloon catheter as described above is considered to have a certain effect in order to improve the pushing characteristics. However, when the distal end of the tubular member or the core wire is a free end, there is a problem that the pushing force is not sufficiently transmitted to the outer shaft.

  Conversely, when the tip of the core wire is fixed to the outer shaft or the like, the push-in characteristics are improved, but when the balloon catheter is pulled out from the body, an excessive pulling force acts on the outer shaft, so that a part of the outer shaft is crushed, so-called Kink may occur. When such a kink occurs, a part of the expansion lumen for expanding the balloon becomes narrow, so that it takes a long time to discharge the liquid expanding the balloon from the balloon. There is a problem that the shrinkage is slow.

  The present invention has been made in view of such circumstances, and can sufficiently transmit the pushing force applied from the proximal side of the balloon catheter to the distal side of the balloon catheter, and when pulling the balloon out of the body, An object of the present invention is to provide a balloon catheter that can prevent kinks and the like from occurring.

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

<1> A balloon, a cylindrical tip outer shaft portion to which at least a part of the balloon is attached, a cylindrical rear end outer shaft portion, and the tip outer shaft portion and the rear end outer shaft portion are connected. In addition, a cylindrical intermediate outer shaft portion having a lower yield point than the front end outer shaft portion and the rear end outer shaft portion, an engagement portion provided in the front end outer shaft portion, and a rear end side is the rear end A balloon catheter comprising: a pressing member that is connected to the outer shaft portion, is inserted through the intermediate outer shaft portion, and has a contact surface that can contact the engagement portion at a distal end.

<2> An inner shaft disposed inside the tip outer shaft portion and having a guide wire lumen for inserting a guide wire therein, a tip side guide wire port formed at a distal end of the inner shaft, A rear end side guide wire port formed at a portion where a proximal end of the inner shaft is joined to the front end outer shaft portion, and the engagement portion is the rear end side guide wire in the front end outer shaft portion. The balloon catheter according to aspect 1, wherein the balloon catheter is provided on the rear end side of the port.

<3> The balloon catheter according to aspect 1 or 2, wherein the pressing member is configured by a coil body including at least one element wire.

<4> The balloon catheter according to aspect 3, wherein the coil body is formed of a stranded coil body formed by twisting a plurality of strands.

<1> The balloon catheter of the present invention not only transmits the pushing force given by the operator from the proximal side of the outer shaft to the distal side in order, but also engages with the contact surface of the pressing member from the middle of the outer shaft. By pushing the joint portion, the pushing force can be effectively transmitted to the distal side.

  Moreover, even if an excessive pulling force is applied due to the extension of the intermediate outer shaft portion where the yield point is set low, it is possible to prevent a part of the balloon catheter from being crushed. Therefore, it is possible to smoothly discharge the expansion liquid from the balloon.

<2> In aspect 2 of the present invention, the inner shaft can be pressed by providing the engaging portion on the rear end side from the rear end side guide wire port of the front end outer shaft portion. Therefore, the pushing force can be transmitted also to the inner shaft.
Therefore, the pushing force given from the proximal side can be effectively transmitted to the tip of the balloon catheter. That is, the pushing characteristic of the balloon catheter can be improved.

<3> In aspect 3 of the present invention, the pressing member is constituted by a coil body made of at least one element wire. With this configuration, it is possible to prevent as much as possible the deterioration of the flexibility of the intermediate outer shaft portion.

<4> In aspect 4 of the present invention, the coil body is constituted by a stranded coil body formed by twisting a plurality of strands, thereby maintaining the flexibility of the coil body and improving the transmission of the pushing force. Can do.

FIG. 1 is an overall view of a balloon catheter according to the present embodiment. FIG. 2 is an enlarged view of a portion A in FIG. 3 is a cross-sectional 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 different from FIG. FIG. 6 is a cross-sectional view seen from the VI-VI direction of FIG.

The balloon catheter of the present embodiment will be described with reference to FIGS.
1 and 2, the left side in the figure is the distal side (front end side) inserted into the body, and the right side is the proximal side (rear end side, base 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, and a connector 60.

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 a tip portion of an extension portion 52 of the inner shaft 50 described later.
The rear end attachment portion 23 is fixed to the outer peripheral surface of the distal end of the outer shaft 30.

  The outer shaft 30 is a cylindrical member that constitutes an expansion lumen 36 for supplying a fluid for expanding the balloon 20. The outer shaft 30 includes a tip outer shaft portion 31, an intermediate outer shaft portion 35, and a rear end outer shaft portion 37 in order from the distal side. The distal outer shaft portion 31 and the intermediate outer shaft portion 35 are formed by welding resin tubes. As the resin, for example, polyamide, polyamide elastomer, polyolefin, polyester, polyester elastomer, or the like is used.

The front outer shaft portion 31 includes a main body shaft portion 31a located on the front end side and a port shaft portion 31b located on the rear end side.
A rear end attaching portion 23 of the balloon 20 is fixed to the outer periphery of the distal end of the main body shaft portion 31a. Further, the main body shaft portion 31a includes an inner shaft 50 described later coaxially. The outer diameter of the main body shaft portion 31a is set to be approximately the same as the outer diameter of the port shaft portion 31b, and is set to about 0.85 mm to about 0.95 mm. In the present embodiment, the outer diameter is about 0.94 mm. is there. The inner diameter h1 of the main body shaft portion 31a is set to about 0.69 mm to about 0.80 mm, and is about 0.78 mm in the present embodiment.

  The port shaft portion 31 b is a portion for attaching a rear end side guide wire port 54, which is a rear end of the inner shaft 50 described later, to the outer shaft 30. The port shaft portion 31b is formed of a resin that is harder than the main body shaft portion 31a. The axial length of the port shaft portion 31b is set to about 5.0 mm to about 10.0 mm, and is set to about 10.0 mm in the present embodiment.

  In order to form the rear end side guide wire port 54, the rear end of the inner shaft 50 is welded to the port shaft portion 31b. For this reason, the expansion lumen 36 in the port shaft portion 31b is biased downward with respect to the central axis as shown in FIG. Further, the cross-sectional shape of the expansion lumen 36 in the port shaft portion 31b is substantially semicircular. As a result, the inner diameter h2 (the length in the height direction in FIGS. 2 and 3) of the expansion lumen 36 in the port shaft portion 31b is smaller than the inner diameter h1 of the main body shaft portion 31a and the inner diameter h3 of the intermediate outer shaft portion 35. ing. In the present embodiment, the inner diameter h2 of the port shaft portion 31b is about 0.38 mm.

The intermediate outer shaft portion 35 is a portion for absorbing a tensile force by stretching when the tensile force acts on the outer shaft 30 and preventing a part of the outer shaft 30 from being crushed. For this reason, the intermediate outer shaft portion 35 is set to have a lower yield point than the distal outer shaft portion 31 and the port shaft portion 31b. In the case of the present embodiment, since the resin constituting the intermediate outer shaft portion 35 is the same as the resin constituting the main body shaft portion 31a of the tip outer shaft portion 31, the resin thickness of the intermediate outer shaft portion 35 is set to the main body shaft portion. The yield point of the intermediate outer shaft portion 35 is lowered by making it thinner than the thickness of the resin 31a.
As a method of reducing the yield point of the intermediate outer shaft portion 35, the resin material can be made flexible.

  The length of the intermediate outer shaft portion 35 in the axial direction is set in a range of about 160.0 mm to about 170.0 mm, and is set to about 160.0 mm in the present embodiment. The cross-sectional shape of the intermediate outer shaft portion 35 is circular, and the outer diameter of the intermediate outer shaft portion 35 is set smaller than the outer diameter of the distal end outer shaft portion 31. Specifically, the outer diameter of the intermediate outer shaft portion 35 is set to about 0.85 mm to about 0.90 mm, and is about 0.88 mm in the present embodiment. The inner diameter h3 of the intermediate outer shaft portion 35 is set larger than the inner diameter h2 of the port shaft portion 31b. In the case of this embodiment, the inner diameter h3 is set to about 0.70 mm to about 0.80 mm, and in the case of this embodiment, it is about 0.75 mm. Due to the difference in inner diameter between the port shaft portion 31b and the intermediate outer shaft portion 35, a step is formed between the intermediate outer shaft portion 35 and the port shaft portion 31b. This step constitutes the engaging portion 33. The height dh of the bottom portion, which is the smallest step portion formed between the intermediate outer shaft portion 35 and the port shaft portion 31b, is that of the strand wire 71 constituting the coil body 70 (pressing member) described later. It is set larger than the length in the radial direction.

  2 and 3 are shown with exaggerated dimensions so that the configurations of the distal outer shaft portion 31 and the outer outer shaft portion 35 can be easily understood. In FIG. 2, the engagement portion 33 that is a joint portion between the port shaft portion 31 b and the intermediate outer shaft portion 35 is illustrated in an arc shape because the joint portion is formed by welding, and therefore is not necessarily a right angle. This is because no significant step is formed.

The rear end outer shaft portion 37 is a metal tubular member called a so-called hypotube. The distal end portion of the rear end outer shaft portion 37 is inserted and fixed to the rear end portion of the intermediate outer shaft portion 35. The lumen of the rear end outer shaft portion 37 constitutes an expansion lumen 36 together with the lumens of the front outer shaft portion 31 and the intermediate outer shaft portion 35 described above.
A connector 60 is attached to the rear end of the rear end outer shaft portion 37. When a liquid such as a shadowing agent 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 this embodiment, the outer diameter of the rear end outer shaft portion 37 is set in a range of about 0.60 mm to about 0.65 mm, and in the case of this embodiment, it is about 0.64 mm. In this embodiment, the inner diameter is about 0.48 mm. The material of the rear end side outer shaft 40 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.

A coil body 70 (pressing member) is attached to the distal portion of the rear end outer shaft portion 37. The coil body 70 is manufactured by twisting a plurality of metal strands 71 on a cored bar, removing residual stress when twisted by a known heat treatment, and extracting the cored bar. is there.
In the present embodiment, six strands 71 are used for the coil body 70, and the strands 71 are so-called flat wires having a rectangular cross section. The length of the wire 71 in the height direction (radial direction) is about 0.05 mm, and the length in the axial direction is about 0.15 mm. The number and dimensions of the strands 71 are appropriately determined in consideration of the outer diameter necessary to be inserted into the intermediate outer shaft portion 35, the rigidity of the coil body 70, and the like. The number is not particularly limited.
The use of such a flat wire is advantageous for the coil body 70 to transmit the pushing force, but the strand 71 may be a so-called round wire having a substantially circular cross section.

  Although the material of the strand 71 is not specifically limited, In the case of this Embodiment, stainless steel is used. As a material other than this, a superelastic alloy such as a Ni-Ti alloy is used. Moreover, you may combine the strand of a different material.

The rear end of the coil body 70 is inserted into the distal end of the rear end outer shaft portion 37, and is fixed to the inner wall of the rear end outer shaft portion 37 by brazing or laser welding. As shown in FIG. 2, the coil body 70 is inserted into the intermediate outer shaft portion 35. That is, the outer peripheral surface of the coil body 70 is not fixed inside the intermediate outer shaft portion 35. In the present embodiment, the outer diameter of the coil body 70 is about 0.72 mm. Further, in a normal state, the contact surface 70a that is the end surface on the distal side of the coil body 70 is in contact with the engaging portion 33 formed by the inner diameter difference between the port shaft portion 31b and the intermediate outer shaft portion 35. .
The coil body 70 has an action of pushing the engaging portion 33 in the axial direction by the contact surface 70a. Therefore, when the pushing force from the proximal side to the distal side is applied, the contact surface It suffices if 70a and the engaging portion 33 are in contact with each other to transmit the pushing force. For this reason, if the abutting surface 70a and the engaging portion 33 come into contact with each other by compressing the intermediate outer shaft portion 35 and the like when a pushing force is applied, the abutting surface 70a and the engaging portion 33 in the normal state. Need not be in contact with each other and may have a slight gap.

The inner shaft 50 is coaxially disposed in the distal end outer shaft portion 31 of the outer shaft 30. The inner shaft 50 is a cylindrical member formed of the same resin as the distal outer shaft portion 31 and the intermediate outer shaft portion 35, and has a guide wire lumen 51 for inserting a guide wire therein. A gap between the inner peripheral surface of the distal end outer shaft portion 31 and the outer peripheral surface of the inner shaft 50 forms an expansion lumen 36 for circulating a liquid for expanding the balloon 20.
The proximal end of the inner shaft 50 is welded to the side surface of the port shaft portion 31 b of the front outer shaft portion 31 to form a rear end side guide wire port 54.

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, and a tip 59 is attached to the extending portion 52 at the distal end.
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 attaching portion 22 of the balloon 20 is fixed to the distal end of the extending portion 52 of the inner shaft 50.

  A pair of radiopaque markers 25 a and 25 b that are separated from each other by a predetermined distance are attached to a portion of the extended portion 52 of the inner shaft 50 that is located inside the expanded portion 21 of the balloon 20.

  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.

  A guide wire (not shown) is inserted in advance into the coronary artery of the heart where there is a stenosis that is the target of treatment, and the balloon catheter 10 is inserted into the body along this guide wire. 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 advanced in the blood vessel along the guide wire, an operator such as a doctor pushes the balloon catheter 10 in the axial direction from the proximal side, and this pushing force is a rear end outer shaft portion 37 which is a metal tube. To the intermediate outer shaft portion 35 made of resin and the distal outer shaft portion 31 are sequentially transmitted to the distal side.

  At the same time, the pushing force is transmitted from the rear end outer shaft portion 37 to the coil body 70 attached to the rear end outer shaft portion 37, and the contact surface 70 a of the coil body 70 presses the engagement portion 33, thereby The proximal end of the shaft portion 31b is pressed. That is, the pushing force is transmitted from the contact surface 70a of the coil body 70, which is a circumferential surface, to the engaging portion 33, which is a circumferential surface, and directly presses the distal end outer shaft portion 31. Therefore, the pushing force can be effectively transmitted to the distal side of the outer shaft 30.

  Further, the intermediate outer shaft portion 35 is configured by a resin tube having a small yield point in order to absorb the tensile force when it is stretched when an excessive tensile force is applied to the outer shaft 30. For this reason, there is a possibility that the transmission of the pushing force from the proximal side may be hindered by the intermediate outer shaft portion 35. However, the coil body 70 is not connected to the port shaft portion 31b via the intermediate outer shaft portion 35. Since the rear end side is directly pressed, the pushing force can be effectively transmitted to the outer end outer shaft portion 31.

  Furthermore, since the coil body 70 presses the rear end side of the port shaft portion 31b to which the proximal end of the inner shaft 50 is attached, the pushing force applied from the proximal side is also transmitted to the inner shaft 50. . For this reason, the pushing force can be transmitted to the distal side not only by the outer shaft 30 but also by the inner shaft 50. Therefore, the pushing force can be effectively transmitted to the tip 59 which is the tip of the balloon catheter 10.

  Furthermore, since the coil body 70 is a stranded coil composed of a plurality of strands 71, it has flexibility. Further, the abutting surface 70a of the coil body 70 and the engaging portion 33 of the port shaft portion 31b are not fixed only by contact, and the outer peripheral surface of the coil body 70 and the inner peripheral surface of the intermediate outer shaft portion 35 are also fixed. Not. For this reason, it is possible to prevent as much as possible the deterioration of the flexibility of the outer shaft 30. Therefore, even when the balloon catheter 10 passes through a bent blood vessel or the like, the balloon catheter 10 can be flexibly bent, and thus can pass through the bent blood vessel or the like satisfactorily.

Under the fluoroscopy, the operator positions the balloon 20 at the stenosis, which is the target site, using the markers 25a and 25b, and then expands the contrast agent, physiological saline, etc. from an indeflator (not shown) connected to the connector 60. Liquid 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 of the balloon 20 and is discharged through the expansion lumen 36 of the outer shaft 30. Thereafter, the balloon catheter 10 is pulled out of the body, and the procedure is completed.

  When the balloon catheter 10 is pulled out of the body or the like, an excessive load may act on the outer shaft 30 when the operator pulls the outer shaft 30 in a state where the balloon catheter 10 is captured by a bent blood vessel or a narrowed portion. . Even in such a case, since the contact surface 70a of the coil body 70 and the engaging portion 33 are in contact with each other and are not fixed, the intermediate outer shaft portion 35 having a low yield point extends in the axial direction. The load can be absorbed. Therefore, even when a load due to a pulling force is applied before discharging the expansion liquid from the balloon 20, it is possible to prevent the expansion liquid from being discharged by, for example, collapsing a part of the expansion lumen 36. Can be prevented.

As described above, the balloon catheter 10 according to the present embodiment not only transmits the pushing force given by the operator from the proximal end of the outer shaft 30 sequentially to the distal side, but also by the coil body 70. Pushing force can be transmitted by pressing the engaging portion 33 from the middle of the shaft 30. At this time, since the engaging portion 33 is pressed by surface contact by the circumferential contact surface 70a of the coil body 70, the pushing force can be transmitted effectively.
Further, by providing the engaging portion 33 on the proximal side of the port shaft portion 31 b and pressing the proximal end side of the inner shaft 50, the pushing force can be transmitted to the inner shaft 50. Therefore, the pushing force given from the proximal side can be effectively transmitted to the tip 59 which is the tip of the balloon catheter 10.

  Furthermore, even if an excessive tensile force is applied due to the extension of the intermediate outer shaft portion 35 where the yield point is set low, it is possible to prevent a part of the balloon catheter 10 from being crushed. Therefore, since the passage of the expansion lumen 36 is secured, the expansion liquid can be smoothly discharged from the balloon 20.

In the embodiment described above, the pressing member is constituted only by the coil body 70, and the coil body 70 is directly attached to the rear end outer shaft portion 37. Such a configuration is advantageous in transmitting the pushing force from the proximal rear end outer shaft portion 37 to the distal tip outer shaft 31.
On the other hand, as shown in FIG. 4, the pressing member can be constituted by a coil body 170 and a core wire 140. That is, the coil body 170 may be connected to the rear end outer shaft portion 37 by the core wire 140. In FIG. 4, the core wire 140 is a taper-shaped wire which becomes thinner toward the distal side. The core wire 140 is attached to the inner peripheral surface of the coil body 170. Further, the tip of the core wire 140 extends beyond the tip of the coil body 170 to the distal side.
Such a configuration using the core wire 140 is advantageous in that the intermediate outer shaft portion 35 is easily extended in the axial direction.

  Further, as shown in FIG. 4, extending the distal end of the core wire 140 to the distal side is advantageous for adjusting the longitudinal rigidity of the balloon catheter 10 by using the rigidity of the core wire 140. However, the distal end of the core wire 140 may be a tip of the coil body 170, that is, the proximal side from the contact surface 170a and may not extend to the distal side from the contact surface 170a.

Further, in the embodiment described above, the engaging portion 33 provided on the proximal end side of the rear end side guide wire port 54 is pressed by the coil body 70 to be pushed into the port shaft portion 31 b and the inner shaft 50. It is configured to transmit power.
On the other hand, as shown in FIG. 5, an engagement portion 233 may be provided on the inner peripheral surface on the distal side of the rear end side guide wire port 54, and the tip end portion of the outer shaft 30 may be pressed by the coil body 270. . The coil body 270 is attached to the rear end outer shaft portion 37 by the core shaft 240. As shown in FIG. 6, the engaging portion 233 is formed of a cylindrical body having six protruding portions 233 a that protrude in the radial direction from the inner peripheral surface of the outer shaft 30.

  As described above, when the outer shaft 30 is pressed on the distal side from the rear end of the inner shaft 50, transmission of the pressing force to the inner shaft 50 is reduced, but the outer shaft 30 is effectively pressed into the tip end portion. Can transmit power. Such a configuration can be applied not only to the so-called quick exchange type balloon catheter described above but also to a so-called over-the-wire type configuration. The rapid exchange type balloon catheter has a configuration in which the guide wire lumen is shortened by providing a rear end side guide wire port on the side of the outer shaft, like the balloon catheter 10 described above. The over-the-wire type balloon catheter has a configuration in which the inner shaft is disposed up to the proximal end of the balloon catheter.

  In the embodiment described above, the pressing member is the coil body 70 made of a stranded coil in which a plurality of strands 71 are twisted together. Since the stranded coil has flexibility and high torque transmission in the axial direction, it is advantageous in maintaining the flexibility of the intermediate outer shaft portion 35 and improving the transmission of the pushing force. However, the pressing member may be formed of a single-wire coil body, a cylindrical member made of a metal pipe or a resin tube. When such a cylindrical member is used, the rigidity can be adjusted by forming a slit in the cylindrical member.

  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 33 Engagement part 35 Middle 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 70 Coil body (Pressing Element)
70a Contact surface 71 Wire

Claims (4)

With balloons,
A cylindrical tip outer shaft portion to which at least a part of the balloon is attached;
A cylindrical rear end outer shaft portion;
A cylindrical intermediate outer shaft portion that connects the tip outer shaft portion and the rear end outer shaft portion and has a lower yield point than the tip outer shaft portion and the rear end outer shaft portion, and
An engagement portion provided on the tip outer shaft portion;
A rear end side is connected to the rear end outer shaft portion, and is provided with a pressing member that is inserted into the intermediate outer shaft portion and has a contact surface that can come into contact with the engagement portion at the front end. Balloon catheter. An inner shaft disposed inside the distal outer shaft portion and having a guide wire lumen for inserting a guide wire therein;
A distal guidewire port formed at the distal end of the inner shaft;
A rear end side guide wire port formed at a portion where the proximal end of the inner shaft is joined to the tip outer shaft portion;
The balloon catheter according to claim 1, wherein the engagement portion is provided on a rear end side of the rear end side guide wire port in the front end outer shaft portion. The balloon catheter according to claim 1 or 2, wherein the pressing member is configured by a coil body made of at least one element wire. The balloon catheter according to claim 3, wherein the coil body is constituted by a stranded coil body formed by twisting a plurality of strands.

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