阅读说明：本技术 球囊导管 (Balloon catheter ) 是由 茂木健 于 2015-12-10 设计创作，主要内容包括：本发明涉及球囊导管,其目的是即使在推拉球囊导管的基端部的情况下,也确保将该推拉力从芯线向外侧管和内侧管这两者传递的功能,并且即使在球囊导管弯曲的情况下,也使芯线适度地移动来确保球囊导管的柔软性。球囊导管(10)具备：球囊(30)；外侧管(20),其连接于该球囊(30)的基端；内侧管(40),其配置于该外侧管(20)的内部,内侧管(40)的顶端连接于球囊(30)的顶端；在该内侧管(40)的外周形成的凹凸部(45)；以及芯线(60),其配置于外侧管(20)与内侧管(40)之间,其中,芯线(60)具备被夹持在外侧管(20)与凹凸部(45)的凹部(45b)之间的膨隆部(80)。(The present invention relates to a balloon catheter, and an object of the present invention is to ensure a function of transmitting a push-pull force from a core wire to both an outer tube and an inner tube even when a proximal end portion of the balloon catheter is pushed or pulled, and to ensure flexibility of the balloon catheter by appropriately moving the core wire even when the balloon catheter is bent. A balloon catheter (10) is provided with: a balloon (30); an outer tube (20) connected to the proximal end of the balloon (30); an inner tube (40) disposed inside the outer tube (20), the distal end of the inner tube (40) being connected to the distal end of the balloon (30); a concave-convex part (45) formed on the outer periphery of the inner pipe (40); and a core wire (60) disposed between the outer tube (20) and the inner tube (40), wherein the core wire (60) has an expanded portion (80) that is sandwiched between the outer tube (20) and a recessed portion (45b) of the uneven portion (45).)

1. A catheter, comprising:

an outer tube;

an inner tube disposed inside the outer tube;

a concave-convex portion provided on an outer periphery of the inner pipe and including a plurality of convex portions and a plurality of concave portions along a longitudinal direction of the inner pipe; and

a core wire disposed between the outer tube and the inner tube,

wherein the core wire is provided with an expanded portion that is sandwiched between the outer tube and one of the plurality of concave portions.

2. The catheter according to claim 1, wherein the concavo-convex portion includes a wire wound around the outer periphery of the inner tube, and a spiral body in which adjacent windings of the wire are separated from each other is formed when the catheter is in an unbent state.

3. The catheter of claim 2,

the surface of the spiral body is covered with resin so that the surfaces of the plurality of projections and the plurality of recesses are smooth,

the bulge is sandwiched between the outer tube and the one recess.

4. The catheter of any one of claims 1-3,

da represents a distance between an inner wall of the outer tube and a bottom of the one recess in a radial direction of the guide tube;

db represents a distance between an inner wall of the outer tube and apexes of the plurality of convex portions in a radial direction of the catheter;

dc represents the outer diameter of the bulge;

satisfies the relationship of Dc > Da > Db.

5. The catheter of any of claims 1-3, wherein the bulge is disposed at a distal end of the core wire.

6. The catheter of any of claims 1-3, wherein the bulge is freely movable relative to the outer tube and the plurality of recesses.

7. The catheter of any one of claims 1-3,

the bulging portion is connected to the distal end of the core wire,

the bulge has a diameter greater than a diameter of the distal end of the core wire.

8. The catheter of any one of claims 1-3, wherein the catheter further has a balloon,

the proximal end of the balloon is connected to the outer tube, and the distal end of the balloon is connected to the inner tube.

9. A balloon catheter having:

a balloon;

an outer tube connected to a proximal end of the balloon;

an inner tube disposed inside the outer tube and connected to a distal end of the balloon;

a concave-convex portion provided on an outer periphery of the inner pipe and including a plurality of convex portions and a plurality of concave portions along a longitudinal direction of the inner pipe; and

a core wire disposed between the outer tube and the inner tube,

wherein the core wire includes an expanded portion sandwiched between the outer tube and one of the plurality of concave portions.

Technical Field

The invention relates to a balloon catheter.

Background

Conventionally, there is known a balloon catheter for dilating a stenosis portion or the like in a lumen of a blood vessel or the like.

The balloon catheter mainly comprises: a balloon as an expansion body; an outer tube attached to a proximal end portion of the balloon; and an inner tube disposed in the lumen of the outer tube, wherein a distal end portion of the inner tube is attached to a distal end portion of the balloon.

The outer tube is a tube for passing an inflation liquid such as a physiological saline solution through an inner lumen provided between the outer tube and the inner tube in order to inflate the balloon, and the inner tube is a tube for passing a guide wire (guide wire) therethrough in order to guide the balloon catheter to the lesion site.

Generally, balloon catheters are used in the following manner: since an operator such as a physician grasps the proximal portion of the balloon catheter and pushes the distal portion into the blood vessel, excellent pushing-in performance for reaching the lesion and excellent operability for the distal portion are required for positioning the balloon at a desired position of the lesion.

As such a balloon catheter, for example, patent document 1 discloses a balloon catheter configured such that, in addition to the above-described configuration, a core wire (core wire) is inserted between a catheter shaft (outer tube) and an inner shaft (inner tube) and the core wire is sandwiched between the outer tube and the inner tube.

According to the balloon catheter described in patent document 1, since only the core wire is clamped between the outer tube and the inner tube,

therefore, the pushing performance of the balloon catheter can be improved without requiring a complicated process.

Patent document 1: japanese patent laid-open publication No. 2012-20077

Disclosure of Invention

Problems to be solved by the invention

However, the balloon catheter described in patent document 1 has the following problems: although the pushability can be improved, when the proximal end portion of the balloon catheter is pulled, the pulling force cannot be transmitted to the balloon catheter via the core wire, and when the pushing force to the proximal end of the balloon catheter is very strong, the core wire moves further to the distal end side between the outer tube and the inner tube, and the core wire is fixed between the outer tube and the inner tube, which impairs the flexibility of the balloon catheter.

The present invention has been made to solve the above-described problems, and an object of the present invention is to ensure a function of transmitting a push-pull force to both of an outer tube and an inner tube via a core wire even when a proximal end portion of a balloon catheter is pushed and pulled, and to ensure flexibility of the balloon catheter by appropriately moving the core wire even when the balloon catheter is bent.

Means for solving the problems

In order to solve the above problem, the balloon catheter according to the invention of claim 1 is characterized by comprising: a balloon; an outer tube connected to a proximal end of the balloon; an inner tube disposed inside the outer tube, a distal end of the inner tube being connected to a distal end of the balloon; a concave-convex part formed on the outer circumference of the inner pipe; and a core wire disposed between the outer tube and the inner tube, wherein the core wire includes an expanded portion sandwiched between the outer tube and the concave portion of the uneven portion.

In the invention according to claim 2, according to the invention according to claim 1, the uneven portion is formed by increasing a pitch (pitch) of a wire of a coil (coil) wound around the outer periphery of the inner pipe.

Further, according to the invention of claim 3, in the invention of claim 2, a surface of the spiral body is covered with a resin so that the surface has a streamline-shaped unevenness along a shape of the wire of the spiral body.

In the invention according to claim 4, according to any one of the inventions of claims 1 to 3, when Da is a distance from the inner wall of the outer tube to the concave portion, Db is a distance from the inner wall of the outer tube to the convex portion, and Dc is an outer diameter of the expanded portion, Dc > Da > Db is set.

ADVANTAGEOUS EFFECTS OF INVENTION

The invention according to claim 1 is a balloon catheter including: a balloon; an outer tube connected to the proximal end of the balloon; an inner tube disposed inside the outer tube, a distal end of the inner tube being connected to a distal end of the balloon; a concave-convex part formed on the outer circumference of the inner pipe; and a core wire disposed between the outer tube and the inner tube, wherein the core wire includes an expanded portion sandwiched between the outer tube and the concave portion of the concave-convex portion, so that even when the proximal end portion of the balloon catheter is pushed or pulled, the push-pull force can be transmitted from the core wire to both the outer tube and the inner tube, and even when the balloon catheter is bent, the core wire can be appropriately moved between the concave-convex portions to secure flexibility of the balloon catheter.

Further, according to the invention of claim 2, in addition to the effect of the invention of claim 1, since the uneven portion is formed by enlarging the pitch of the wire material of the spiral wound around the outer periphery of the inner tube, the push-pull force can be transmitted from the core wire to both the outer tube and the inner tube with a simple structure, and the kink (kink) of the inner tube can be prevented.

Further, according to the invention of claim 3, in the invention of claim 2, since the surface of the spiral body is covered with the resin so that the surface has linear irregularities along the shape of the wire of the spiral body, in addition to the effect of the invention of claim 2,

the bulge portion can be moved smoothly (Smooth).

Further, according to the invention of claim 4, in the case where Da is the distance from the inner wall of the outer tube to the concave portion, Db is the distance from the inner wall of the outer tube to the convex portion, and Dc is the outer diameter of the swollen portion, Dc > Da > Db is set according to any one of the inventions of claims 1 to 3, and therefore, in addition to the effect of any one of the inventions of claim 1 to 3, it is possible to more favorably transmit the push-pull force from the core wire to both the outer tube and the inner tube when the proximal end portion of the balloon catheter is pushed and pulled.

Drawings

Fig. 1 is an overall view schematically showing a balloon catheter of a first embodiment of the present invention.

Fig. 2 is a partially enlarged view of the area a of fig. 1.

Fig. 3 is an overall view schematically showing a balloon catheter of a second embodiment.

Fig. 4 is a partially enlarged view of the region B of fig. 3.

Fig. 5 is an overall view schematically showing a balloon catheter of a third embodiment.

Fig. 6 is a partially enlarged view of the region C of fig. 5.

Fig. 7 is an enlarged view of a main portion of the balloon catheter of the fourth embodiment.

Fig. 8 is an explanatory view for explaining a moving state of the bulge portion.

Description of the reference numerals

10. 100, 200, 300: a balloon catheter; 20: an outer tube; 28: an inner lumen of the outer tube; 30: a balloon; 34: an inner lumen of the balloon; 40. 140, 240: an inner tube; 45. 145, 245: a concave-convex portion; 45a, 145a, 245 a: a convex portion; 45b, 145b, 245 b: a recess; 60: a core wire; 60 a: a top end portion of the core wire; 60 b: a base end portion of the core wire; 150. 250: metal wire

Detailed Description

(first embodiment)

The structure of the balloon catheter according to the present embodiment will be described below with reference to the drawings.

Fig. 1 is an overall view schematically showing a balloon catheter according to a first embodiment of the present invention, and fig. 2 is a partially enlarged view of a region a of fig. 1.

In fig. 1 and 2, the left side is a distal side (distal side) to be inserted into the body, and the right side is a proximal side (proximal side) to be operated by an operator such as a doctor.

The balloon catheter 10 shown in fig. 1 includes: a balloon 30; an outer tube 20 connected to a proximal end portion of the balloon 30; an inner tube 40 inserted into the outer tube 20, and having a distal end of the inner tube 40 joined to a distal end of the balloon 30; a hypotube (hypotube)23 joined to the base end of the outer tube 20; a core wire 60 inserted between the outer tube 20 and the inner tube 40, a proximal end of the core wire 60 being joined to a distal end portion of the hypotube 23; and a connector (connector)70 engaged with the base end of the hypotube 23.

The balloon 30 is composed of an expanding portion 31, a distal end mounting portion 32, and a rear end mounting portion 33, wherein the expanding portion 31 is expanded by the pressure of the liquid injected inside, the distal end mounting portion 32 is joined to the distal end of the distal end portion 40a of the inner tube 40, the rear end mounting portion 33 is joined to the outer peripheral surface of the distal end of the outer tube 20, and the expanding portion 31 is expanded by the pressure of the liquid injected inside, whereby the inner cavity 34 is formed into a bag shape. Also, the lumen 34 of the balloon 30 communicates with the lumen 28 of the outer tube 20.

The outer tube 20 is a tubular body having: a distal end outer tube 21 located on the distal end side, a proximal end outer tube 22 located on the proximal end side, and an inner cavity 28 continuous from the distal end outer tube 21 to the proximal end outer tube 22. In addition, a liquid for expanding the balloon 30 can be flowed through the lumen 28 of the outer tube 20.

The distal-end outside tube 21 and the proximal-end outside tube 22 are formed of, for example, a resin such as polyamide (polyamide), polyamide elastomer (polyamide elastomer), polyolefin (polyolefin), polyester (polyester), or polyester elastomer (polyester elastomer).

The distal end outer tube 21 is composed of a main tube 21a positioned on the distal end side and a port tube (tube) 21b positioned on the proximal end side, and a rear end attachment portion 33 of the balloon 30 is joined to the outer peripheral surface of the distal end of the main tube 21 a.

The mouthpiece 21b has an inner cavity communicating with the inner cavity 28, and a base end portion 40b of the inner tube 40 described later has an opening portion (rear end side opening portion) 44 opened. The mouthpiece 21b may be made of a resin harder than the main body tube 21 a.

The inner tube 40 is a tubular body of one of the following types: the distal end portion 40a and the rear end portion 40b are provided, and are inserted coaxially with the outer tube 20 into the lumen 28 of the distal end outer tube 21 of the outer tube 20, and have a lumen 41 formed so as to be inserted by a guide wire, not shown.

In addition, an uneven portion 45 composed of a spiral or annular convex portion 45a and a concave portion 45b is formed on the outer periphery of the inner tube 40 over the entire length in the longitudinal direction.

The inner tube 40 may be formed of the same resin as the distal end outer tube 21 and the proximal end outer tube 22.

The inner tube 40 has a distal end portion 40a protruding from the distal end of the distal end outer tube 21, and a tip (tip)42 made of a flexible resin is attached to the distal end of the distal end portion 40 a.

The hypotube 23 is a tubular body made of metal, and has a distal end portion to which the proximal end outside tube 22 is joined on the outer peripheral surface, and a proximal end portion to which the connector 70 is attached.

A proximal end portion 60b of a core wire 60, which will be described later, is joined to the inside of the distal end of the hypotube 23.

As a material of the hypotube 23, for example, super elastic alloy such as stainless steel and Ni — Ti alloy can be used.

The core wire 60 is composed of a distal end portion 60a, a proximal end portion 60b, and a bulge portion 80, wherein the bulge portion 80 is joined to the distal end of the distal end portion 60a and has a larger diameter than the wire diameter of the distal end portion 60 a.

The proximal end portion 60b of the core wire 60 is joined to the inside of the distal end of the hypotube 23 by welding or joining means such as an adhesive, and the bulging portion 80 as the distal end portion of the core wire 60 is sandwiched between the outer tube 20 and the concave portion 45b of the concave-convex portion 45.

The connector 70 is a tubular member made of resin, and when a liquid is supplied from a not-shown pressurizing device (introducer) attached to the proximal end of the connector 70, the liquid enters the lumen 34 of the balloon 30 from the hypotube 23 via the lumen 28, and expands the balloon 30.

The tip 42 is a tapered cylindrical member having an outer diameter gradually decreasing toward the distal end, and has a distal end side opening 43 at the distal end. The tip 42 may be formed of a resin softer than the resin forming the distal end portion 40a of the inner tube 40.

Two radiopaque markers (markers) 35a and 35b are attached to the distal end portion 40a of the inner tube 40 at a predetermined distance inside the dilating portion 31 of the balloon 30.

Based on the above configuration, a case where the balloon catheter 10 of the present embodiment is used in a procedure for dilating a stenosed portion of a coronary artery of a heart will be described.

In a coronary artery of a heart where a stenosis is present as a treatment target, a guide wire is inserted in advance, and first, the operator inserts the proximal end of the guide wire from the distal end side opening 43 of the balloon catheter 10, passes the guide wire through the lumen 41 of the inner tube 40, takes out the guide wire from the rear end side opening 44, then pushes the proximal end of the balloon catheter 10 in the axial direction toward the distal end side while holding the guide wire, and advances the balloon catheter 10 in a blood vessel of a patient.

The pushing force of the operator is first transmitted from the hypotube 23 to the outer tube 20 and the core wire 60. Here, since the bulge portion 80 which is the tip end portion of the core wire 60 is sandwiched between the outer tube 20 and the concave portion 45b of the concave-convex portion 45, the pushing force transmitted to the outer tube 20 and the core wire 60 is transmitted to the inner tube 40 and the outer tube 20.

Further, since the bulge portion 80 is sandwiched between the outer tube 20 and the concave portion 45b of the concave-convex portion 45 and is not fixed, when the balloon catheter 10 needs to be bent toward the core wire 60 side in accordance with the meandering state of the blood vessel of the patient, the bulge portion 80 can move toward the concave portion 45b adjacent to the distal end side, and the flexibility of the balloon catheter is ensured. On the other hand, when the balloon catheter 10 needs to be bent to the side opposite to the core wire 60 side, the bulging portion 80 can move to the concave portion 45b adjacent to the proximal end side, and the flexibility of the balloon catheter 10 is ensured.

If the bulging portion 80 is sandwiched and fixed between the outer tube 20 and the concave portion 45b of the concave-convex portion 45, for example, even if the balloon catheter 10 needs to be bent toward the core wire 60 side or the side opposite to the core wire 60 side in accordance with the meandering state of the blood vessel of the patient, the balloon catheter 10 becomes difficult to be bent due to the rigidity of the core wire 60 or the like. In contrast, in the balloon catheter 10 of the present embodiment, the rigidity of the core wire 60 does not inhibit the change of the balloon catheter 10 to the curved state, and the balloon catheter 10 is flexibly curved in accordance with the meandering state of the blood vessel of the patient.

When the force for pushing the core wire 60 exceeds a predetermined value, the bulging portion 80 moves toward the concave portion 45b adjacent to the distal end side, so that an excessive force is not transmitted to the distal end of the balloon catheter 10, and the operator can safely operate the balloon catheter 10.

Thereafter, the operator confirms the markers 35a and 35b under fluoroscopy, positions the balloon 30 at the target site, that is, the stricture, and supplies liquid from a pressurizing device, not shown, connected to the connector 70. At this time, the liquid flows into the lumen 28 of the outer tube 20, flows out into the lumen 34 of the balloon 30 from the distal end of the distal end outer tube 21, and expands the balloon 30 and the stricture portion.

After the operator dilates the stricture portion with the balloon 30, the liquid is discharged from the balloon 30 with the pressurizing device. That is, the liquid flows out of the balloon 30 and is discharged through the lumen 28 of the outer tube 20. Thereafter, the balloon catheter 10 is pulled out of the patient, and the operation is terminated.

When the operator pulls out the balloon catheter 10 to the outside of the patient, the pulling force is first transmitted to the outer tube 20 and the core wire 60 via the hypotube 23. Here, since the bulge portion 80 which is the distal end portion of the core wire 60 is sandwiched between the outer tube 20 and the concave portion 45b of the concave-convex portion 45, the pulling-out force transmitted to the outer tube 20 and the core wire 60 is transmitted to the inner tube 40 and the outer tube 20, and the balloon catheter 10 can be smoothly pulled out to the outside of the patient.

The balloon catheter 10 of the present embodiment can achieve the following operational effects.

(1) The balloon catheter 10 of the present embodiment includes: a balloon 30; an outer tube 20 connected to the proximal end of the balloon 30; an inner tube 40 disposed inside the outer tube 20, a distal end of the inner tube 40 being connected to a distal end of the balloon 30; a concave-convex portion 45 formed on the outer periphery of the inner tube 40; and a core wire 60 disposed between the outer tube 20 and the inner tube 40, wherein the core wire 60 includes an expanded portion 80 sandwiched between the outer tube 20 and the concave portion 45b of the concave-convex portion 45, and therefore, even when the proximal end portion of the balloon catheter 10 is pushed or pulled, the push-pull force thereof can be transmitted from the core wire 60 to both the outer tube 20 and the inner tube 40.

(2) Even when the balloon catheter 10 is bent, the bulge portion 80 of the core wire 60 can be moved appropriately between the concave portions 45b of the concave-convex portion 45, and the flexibility of the balloon catheter 10 can be ensured.

(second embodiment)

Fig. 3 is an overall view schematically showing a balloon catheter of a second embodiment, and fig. 4 is a partially enlarged view of a region B of fig. 3.

In fig. 3 and 4, the left side is a distal side (distal side) to be inserted into the body, and the right side is a proximal side (proximal side) to be operated by an operator such as a doctor.

In fig. 3 and 4, the same reference numerals are given to portions common to those of embodiment 1.

The balloon catheter 100 shown in fig. 3 is different from the inner tube of the balloon catheter 10 of embodiment 1. That is, the inner tube 140 of the present embodiment is a tubular body of: has a distal end portion 140a and a rear end portion 140b, and is inserted coaxially with the outer tube 20 into the lumen 28 of the distal end outer tube 21 of the outer tube 20, and the inner tube 140 has a lumen 141 formed so as to be capable of being inserted by a guide wire, not shown.

Further, on the outer periphery of the inner tube 140, a metal wire 150 having a circular cross section is spirally wound in the longitudinal direction over the entire length of the inner tube 140 to increase the pitch, thereby forming a concave-convex portion 145 composed of a convex portion 145a and a concave portion 145 b.

In addition, in the present embodiment, in order to form the concave-convex portion 145, a metal wire rod having a circular cross section is spirally wound in the longitudinal direction and the pitch is expanded, but the concave-convex portion 145 may be formed by spirally winding a resin wire rod having a circular cross section in the longitudinal direction and the pitch is expanded, or the concave-convex portion 145 may be formed by spirally winding a metal wire rod having a rectangular cross section or a resin wire rod having a rectangular cross section in the longitudinal direction and the pitch is expanded.

The uneven portion 145 may be formed by spirally winding a plurality of metal wires having a circular cross section or a rectangular cross section or a plurality of resin wires having a circular cross section or a rectangular cross section in the longitudinal direction and enlarging the pitch, or the uneven portion 145 may be formed by twisting a plurality of metal wires having a circular cross section or a plurality of resin wires having a circular cross section into one twisted wire and spirally winding the twisted wire in the longitudinal direction and enlarging the pitch.

The uneven portion 145 may be formed by spirally winding a plurality of twisted wires formed by twisting a plurality of metal wires having a circular cross section or a plurality of resin wires having a circular cross section in the longitudinal direction and enlarging the pitch.

The bulge portion 80, which is the tip end portion of the core wire 60, is sandwiched between the outer tube 20 and the concave portion 145b of the concave-convex portion 145.

When the balloon catheter 100 of the present embodiment including the above configuration is used in a procedure for dilating a stenosed portion existing in a coronary artery of the heart, since the concave-convex portion 145 is formed by enlarging the pitch of the metal wire 150 wound around the outer periphery of the inner tube 140, the push-pull force can be transmitted from the core wire 60 to both the outer tube 20 and the inner tube 140 with a simple configuration, and the kinking of the inner tube 140 can be prevented.

(third embodiment)

Fig. 5 is an overall view schematically showing a balloon catheter of a third embodiment, and fig. 6 is a partially enlarged view of a region C of fig. 5.

In fig. 5 and 6, the left side is a distal side (distal side) to be inserted into the body, and the right side is a proximal side (proximal side) to be operated by an operator such as a doctor.

In fig. 5 and 6, the same reference numerals are given to portions common to embodiment 1.

The balloon catheter 200 shown in fig. 5 is different from the inner tube of the balloon catheter 10 of embodiment 1. That is, in the inner tube 240 of the present embodiment, the metal wire 250 having a rectangular cross section is spirally wound in the longitudinal direction over the entire length of the inner tube 240 at the outer periphery thereof, and the pitch is increased, and the resin 260 is coated so that the surface thereof has streamline irregularities along the shape of the metal wire having a rectangular cross section, thereby forming the uneven portion 245 composed of the convex portion 245a and the concave portion 245 b.

As the resin material covered with the linear irregularities along the shape of the metal wire rod having the rectangular cross section, for example, resins such as polyamide, polyamide elastomer, polyolefin, polyester, and polyester elastomer can be used.

In the present embodiment, in order to form the uneven portion 245, the metal wire material 250 having a rectangular cross section is spirally wound in the longitudinal direction and the pitch is increased, but the uneven portion 245 may be formed by spirally winding the resin wire material having a rectangular cross section in the longitudinal direction and increasing the pitch, or the uneven portion 245 may be formed by spirally winding the metal wire material having a circular cross section or the resin wire material having a circular cross section in the longitudinal direction and increasing the pitch.

Further, the uneven portion 245 may be formed by spirally winding a plurality of metal wires having a circular cross section or a rectangular cross section or a plurality of resin wires having a circular cross section or a rectangular cross section in the longitudinal direction and enlarging the pitch, or the uneven portion 245 may be formed by spirally winding a single twisted wire formed by twisting a plurality of metal wires having a circular cross section or a plurality of resin wires having a circular cross section in the longitudinal direction and enlarging the pitch.

Further, the uneven portion 245 may be formed by spirally winding a plurality of twisted wires formed by twisting a plurality of metal wires having a circular cross section or a plurality of resin wires having a circular cross section in the longitudinal direction and enlarging the pitch.

The bulge portion 80, which is the tip end portion of the core wire 60, is sandwiched between the outer tube 20 and the concave portion 245b of the concave-convex portion 245.

When the balloon catheter 200 of the present embodiment having the above-described configuration is used in a procedure for dilating a stenosed portion existing in a coronary artery of the heart, since the resin 260 is coated so as to form the uneven portion 245 composed of the convex portion 245a and the concave portion 245b in such a manner that the surface thereof has a streamline uneven shape along the shape of the metal wire rod having the rectangular cross section, the balloon catheter 80 can be smoothly moved in addition to the effect of the invention of embodiment 2.

(fourth embodiment)

Fig. 7 is an enlarged view of a main portion of a balloon catheter 300 according to a fourth embodiment, and fig. 8 is an explanatory view for explaining movement of a bulge 82. In the present embodiment, when Da is the distance from the inner wall of the outer tube 20 to the concave portion 245b, Db is the distance from the inner wall of the outer tube 20 to the convex portion 245a, and Dc is the outer diameter of the bulge portion 82, Dc > Da > Db is set.

According to the balloon catheter 300 of the present embodiment, when Da is the distance from the inner wall of the outer tube 20 to the concave portion 245b, Db is the distance from the inner wall of the outer tube 20 to the convex portion 245a, and Dc is the outer diameter of the bulge portion 82, Dc > Da > Db can be set, and therefore the pushing performance (pushability) from the core wire 60 to both the inner tube 240 and the outer tube 20 can be further improved.

As shown in fig. 8, when the balloon catheter 300 needs to be bent toward the core wire 60a in accordance with the meandering state of the blood vessel of the patient, the bulging portion 82 can move toward the concave portion 245b adjacent to the distal end side (left side in the drawing), and flexibility of the balloon catheter 300 is ensured. On the other hand, when the balloon catheter 300 needs to be bent to the side opposite to the core wire 60a side, the bulging portion 82 can move to the concave portion 245b adjacent to the proximal end side (right side in the drawing), and the flexibility of the balloon catheter 10 is ensured.

Although the point at which the swollen portion 82 moves toward the concave portion 245b adjacent to the tip end side (left side in the drawing) and the base end side (right side in the drawing) is described in fig. 8, it is understood that the swollen portion 80 in the first to third embodiments also moves in the same manner.

The balloon catheters according to the first to fourth embodiments are described as means for treatment of a cardiac blood vessel, but may be used in various operations such as an operation for expanding a blood vessel of a lower limb or a shunt (shunt) for dialysis.