JP2003320032A - Balloon catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a balloon catheter of satisfactory operability excellent in followability while securing torque transmission performance and press-in performance. <P>SOLUTION: This balloon catheter has a tube-like catheter main body 2 constituted of a metal material. A groove 21 for storing the whole or one portion of a guide wire 100 is formed along a longitudinal direction on an outer circumferential face of the catheter main body 2. The groove 21 is formed by plastic-working a tube wall of the catheter main body 2 to be plastically deformed. A wall thickness of the tube wall of the catheter main body 2 is substantially constant over the whole circumference of the tube including a portion formed with a groove 21. Flexural rigidity of the catheter main body 2 when bent to bring the portion formed with a groove 21 into an inside is smaller than that when bent to other direction. The catheter main body 2 is bent easily by rotating the catheter to follow bending in a blood vessel, so as to provide the excellent followability. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balloon catheter having a balloon at its tip, and more particularly to a rapid exchange type balloon catheter.

[0002]

2. Description of the Related Art PTCA (Percutaneous Translumina)
l Coronary Angioplasty: A catheter used for percutaneous coronary angioplasty (hereinafter referred to as "PTCA catheter"), which is a balloon catheter for vascular insertion, in addition to a balloon lumen for dilating a balloon. , The guide wire lumen for inserting the guide wire is formed over the entire length of the catheter, and the guide wire is inserted into the guide wire inserting lumen before insertion of the catheter into the blood vessel so that the tip of the guide wire precedes. Then, the distal end of the guide wire together with the catheter is guided to the target site (near the blood vessel stenosis).

A wide variety of PTCA catheters are available, suitable for cases such as the size of the stenosis and the diameter of the blood vessel, or different balloon sizes for the gradual expansion of the stenosis. However, there is a case where it is necessary to replace the PTCA catheter after inserting the blood vessel. In addition, even when a plurality of indwelling devices called stents for securing the inner diameter of the blood vessel are installed, the catheter may be removed / inserted from the blood vessel several times.

It is preferable to replace the catheter with the guide wire left in the blood vessel in order to reduce the burden on the patient, the operation time and labor, the prevention of infection and the like.

However, in the conventional catheter, as described above, since the lumen for inserting the guide wire is formed over the entire length of the catheter, the guide wire is left in the blood vessel while the guide wire is placed outside the body end side ( In order to exchange the catheter from the proximal side, the extracorporeal end of the guide wire must protrude from the proximal end of the catheter by a length equal to or longer than the entire length of the catheter, that is, the guide wire length is at least twice the catheter length. Is required, and there is a problem that the long protruding guide wire deteriorates operability.

[0006] Therefore, a lumen for inserting a guide wire is formed only at the distal end of the catheter, that is, a rapid-exchange type catheter, that is, a distal end opening of the catheter and a number from the distal end opening to the proximal side. There is proposed a catheter which is formed so as to communicate with a side hole provided at a position separated by about cm, and which is configured so that the short lumen and the guide wire are engaged with each other (Japanese Patent Publication No. 4-9548). In this catheter, the catheter can be exchanged while the guide wire is left in the blood vessel without the extracorporeal end of the guide wire protruding from the proximal end of the catheter.

[0007]

By the way, when guiding the catheter with the guide wire inserted into the guide wire insertion lumen to the target site in the body, the guide wire and the catheter are removed because the blood vessel meanders. It is necessary to match the bending of the meandering blood vessel. In order to match this bend, the operation of advancing and retracting and rotating the guide wire and the catheter is performed on the external end side, but such an operation needs to be reliably transmitted to the distal end side of the catheter. Torque transmission, pushability, and kink resistance are required.

In a catheter having a relatively small diameter applied to a thin blood vessel, the body of the catheter (catheter body)
If it is made of a synthetic resin material, the so-called stiffness becomes weak and it becomes easy to kink, or it becomes impossible to obtain sufficient torque transmission and pushability. Therefore, a metal tube having bending elasticity is used as a catheter body of a catheter having a relatively small diameter.

However, when the catheter main body is made of a metal tube, the bending rigidity is too high especially at the distal end side of the catheter main body to lack flexibility, so that the catheter body can be smoothly and reliably guided along the preceding guide wire in a curved blood vessel. However, there is a drawback in that the following ability (following ability) that can proceed to (2) is poor.

An object of the present invention is to provide a balloon catheter which has excellent operability and excellent followability while ensuring torque transmission and pushability.

[0011]

These objects are achieved by the present invention described in (1) to (7) below.

(1) A tubular catheter main body made of a metal material, an expandable / contractible balloon installed on the distal end side of the catheter main body, and an inner cavity of the catheter main body. A balloon lumen communicating with the balloon lumen, which is opened to the distal end side of the balloon and is formed so as to be surrounded by a tube wall in the balloon,
A balloon catheter having a guide wire lumen for inserting a guide wire from the distal end side of the balloon to the outside of the catheter main body, wherein the catheter main body has a tube wall depressed at least on the outer peripheral surface of the distal end side portion thereof. A balloon having a groove formed along the longitudinal direction in such a manner that the wall thickness of the tube wall of the catheter body is substantially constant over the entire circumference including the groove forming portion. catheter.

(2) The balloon catheter according to (1), wherein the groove is formed over substantially the entire length of the catheter body.

(3) The balloon catheter according to (1) or (2) above, which has a portion where the depth of the groove decreases continuously or stepwise toward the proximal direction.

(4) The balloon catheter according to any one of (1) to (3), wherein at least a part of the guide wire can be inserted into the groove.

(5) The balloon catheter according to any of (1) to (4) above, wherein the proximal end opening of the guide wire lumen is formed so as to be continuous with the distal end of the groove.

(6) In any one of the above (1) to (5), which has an inner tube inserted through the balloon and has the guide wire lumen formed by an inner cavity of the inner tube. The balloon catheter described.

(7) The balloon catheter according to any one of (1) to (6), wherein the catheter body is made of stainless steel or pseudoelastic alloy.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The balloon catheter of the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

<First Embodiment> FIG. 1 shows a balloon catheter according to a first embodiment of the present invention (hereinafter simply referred to as "catheter").
2) is a perspective view showing a state in which the catheter is inserted into the inner cavity of the guiding catheter, FIG. 2 is a longitudinal sectional view of the distal end portion of the catheter shown in FIG. 1, and FIG. 3 is a sectional view taken along line XX in FIG. FIG. 4 is a cross-sectional view (cross-sectional view) taken along the line YY in FIG. 2, and FIG. 5 is a perspective view of the catheter body of the catheter shown in FIG. In the following description, the right side in FIGS. 1 and 2 is referred to as the “base end” and the left side is referred to as the “tip”.

A catheter 1 shown in FIG. 1 is a rapid exchange type balloon catheter, and comprises a catheter body 2 having bending elasticity and an expandable / contractible balloon (expandable body) installed on the distal end side of the catheter body 2. )
3 and a hub 4 installed on the proximal end side of the catheter body 2. The configuration of each unit will be described below.

The catheter body 2 is made of a metal material and has a tubular shape. Thereby, the catheter body 2
Has higher rigidity (bending rigidity, torsional rigidity) than those made of various synthetic resin materials (plastics). Therefore, the catheter main body 2 has a so-called strong elasticity even if its outer diameter is relatively small. as a result,
The catheter 1 has a torque transmissibility that allows the rotational force applied at the proximal end side to be reliably transmitted to the distal end side, and the force pushed by the operator to advance the inside of the blood vessel from the proximal end side to the distal end side. The pushability that can be transmitted is excellent.

That is, the catheter 1 of the present invention has excellent operability even when the outer diameter of the catheter body 2 is comparatively small, and therefore can be inserted into a comparatively thin blood vessel. Are especially suitable. From this, the outer diameter (average outer diameter) of the catheter body 2 is not particularly limited, but is preferably about 0.2 to 3 mm,
More preferably, it is about 0.3 to 2 mm. The inner and outer diameters of the catheter body 2 may change along the longitudinal direction thereof.

The length of the catheter body 2 is not particularly limited and may be appropriately determined according to the site of use of the catheter 1, the case, etc., but is usually about 100 to 200 cm.

Various metal materials can be used as the constituent material of the catheter body 2, but a pseudoelastic alloy (superelastic alloy) such as Ni-Ti alloy or stainless steel is used from the viewpoint of physical properties and safety. preferable. That is, the pseudo-elastic alloy or stainless steel easily returns to its original shape by unloading stress. It should be noted that the pseudo-elastic alloy includes those subjected to hot working, cold working, or a combination thereof, and includes those subjected to other working as long as it returns to its original shape after deformation. Therefore, in the stress-strain curve, not only the stress is almost constant even if the strain increases, but also the stress increases as the stress increases.

As shown in FIG. 2, this catheter body 2
The lumen of the above constitutes a balloon lumen 11 communicating with the below-mentioned balloon 3. The balloon lumen 11 functions as a flow path that supplies a working fluid for expanding and contracting the balloon 3 to the internal space of the balloon 3.

As shown in FIGS. 3 to 5, one groove (recess) 21 is formed on the outer peripheral surface (side surface) of the catheter body 2 along the longitudinal direction (axial direction) of the catheter body 2. Is formed so as to be depressed. The whole or a part of the guide wire 100 can be housed (inserted) in the groove 21.

As shown in FIG. 3, the cross-sectional shape of the groove 21 is
In the present embodiment, the shape is substantially arcuate, but the shape is not limited to this, and may be, for example, V-shaped, U-shaped, rectangular, elliptical (semi-elliptical), or the like.

The groove 21 is formed by subjecting the tube wall of the catheter body 2 having a circular cross section to plastic working and plastic deformation. This plastic working can be easily performed by the following method, for example. (1) Insert the unprocessed catheter body 2 into a mold having a semicircular cross section having an inner surface having the same curvature as the outer peripheral surface (side surface) of the catheter body 2,
A jig (for example, a pin) having a protrusion having a shape corresponding to the groove 21 is provided at a position facing the mold, and the mold and the jig are fixed with the jig being pressed against the catheter body 2. A method in which the catheter body 2 is relatively moved so as to be pulled out in the longitudinal direction (axial direction) from between the tool and the groove 21 is gradually formed along the longitudinal direction. (2) A male type having a ridge having a shape corresponding to the groove 21 is pressed on the outer peripheral surface of the catheter body 2 supported by the mold to form the groove 21 for the length of the ridge at a time. Method.

In such plastic working, the projection wall of the jig or the tube wall of the portion pressed by the male ridge escapes to the inner lumen side of the catheter body 2 to form the protruding portion 22. The wall thickness of the tube wall of the main body 2 is substantially constant over the entire circumference of the tube including the portion where the groove 21 is formed. As a result, there is no reduction in strength in the portion where the groove 21 is formed, and even if the wall thickness of the catheter body 2 is relatively thin, it is possible to effectively prevent deformation and damage in the portion where the groove 21 is formed. it can.

When the catheter body 2 is made of a pseudoelastic alloy, the groove 21 may be formed at the same time as or before and after cold working and hot working.

Since the catheter body 2 is formed with such a groove 21, the catheter body 2 has the property (characteristic) that its bending rigidity varies depending on the bending direction. That is, the bending rigidity of the catheter body 2 when curved so that the formation portion of the groove 21 is on the inside (state shown by A in FIG. 5) is curved so that the formation portion of the groove 21 is on the outside. When (the state shown by B in FIG. 5), the groove 2
The inner part (or outer part) is different from the formation part of 1 by 90 °
It is smaller than the bending rigidity when it is bent so as to be (state shown by C and D in FIG. 5). As a result, the catheter body 2 in the portion where the groove 21 is formed becomes easily bendable selectively in the direction indicated by A in FIG.

Since the catheter body 2 has such a property, the catheter 1 can be smoothly and reliably inserted into the curved blood vessel along the preceding guide wire 100 (hereinafter referred to as "followability"). ) Will be excellent. This is because when the catheter body 2 is inserted / advanced along the guide wire 100, the guide wire 100 first precedes the guide wire 100 in accordance with the bend of the blood vessel that is complicatedly branched / curved, and the blood vessel is selected as the target site. By inserting and rotating the catheter 1 along the bend of the guide wire 100 so that the formation site of the groove 21 is on the inner side of the curve, the catheter body 2 easily bends following the bend of the blood vessel. This is because it can be inserted and moved forward smoothly and reliably.

As described above, the catheter 1 exhibits excellent followability. In addition, as described above, the catheter 1
The catheter body 2 has a relatively high rigidity and a high rigidity, and has excellent torque transmission and pushability. That is, the catheter 1 of the present invention has both excellent torque transmission and pushability and excellent followability,
The operability is extremely good.

Here, the inventor of the present invention uses the groove 2 as described above.
In order to demonstrate that the bending rigidity of the catheter body 2 varies depending on the bending direction, the three-point bending test of a metal tube as described below was performed. In this 3-point bending test, the amount of bending when the metal tube was 3-point bent under the following conditions was measured. <Metal tube> Material: SUS304, outer diameter: 0.55 mm, inner diameter: 0.
33 mm, wall thickness: 0.11 mm, groove 21 depth: 0.0
9 mm <Bending conditions> Punch diameter of fulcrum: 5 mm, Distance between fulcrums: 10 mm, Bending speed: 1 mm / min, Maximum load: 0.98 kgf

FIG. 8 is a graph showing the measured data of the load and the bending amount in the above-described three-point bending test on the vertical axis and the horizontal axis, respectively. In FIG. 8, when bent above the groove (state indicated by A in FIG. 5), bent below the groove (state indicated by B in FIG. 5), and bent sideways (C in FIG. 5). Or the data shown in D) and the case without a groove (normal: before forming a groove) are shown. As can be seen from FIG. 8, the loads 0.
The flexure amounts at 98 kgf were as follows (the larger the flexure amount, the smaller the bending rigidity). Above groove: 0.45mm Below groove: 0.33mm Next to groove: 0.30mm Without groove: 0.29mm

From the results of this three-point bending test, the bending rigidity when the metal tube is bent so that the formation portion of the groove 21 is on the inside (on the groove) is smaller than when bending in other directions. It became clear. It was also found that the bending rigidity when curved in the groove below and laterally of the groove retains almost the same rigidity as in the case without the groove.

In the present invention, the provision of the groove 21 also contributes to the reduction of the diameter of the guiding catheter 200. That is, as shown in FIG. 3, in the catheter 1, since the guide wire 100 is housed in the groove 21,
Outer peripheral surface of catheter body 2 and guiding catheter 2
It is not necessary to provide a gap for inserting the guide wire 100 between the guiding catheter 100 and the inner peripheral surface of the guide wire 00, so that the guiding catheter 200 can be used even if its inner diameter is as small as the outer diameter of the catheter body 2. can do. Thereby, the guiding catheter 200 and the catheter 1 can be inserted (introduced) into a thinner blood vessel.

Further, since the guide wire 100 is housed in the groove 21, the lateral movement of the guide wire 100 with respect to the catheter 1 is fixed, and the play can be eliminated. Accordingly, when the catheter 1 is operated, the guide wire 100 is displaced together with the catheter 1,
The above-mentioned torque transmissibility and pushability are more excellent.

The groove 21 also has a function as a guide path for moving the guide wire 100 along the groove 21.

In the present embodiment, the groove 21 is formed over substantially the entire length of the catheter body 2, but in the present invention, the groove 21 is formed only at the distal end side portion of the catheter body 2. It may be.

The cross-sectional shape, the maximum depth, the width, etc. of the groove 21 may be the same or may change along the longitudinal direction of the catheter body 2.

Further, it is preferable that a layer (not shown) made of a hydrophilic polymer substance having lubricity in a wet state is formed on the outer peripheral surface of the catheter body 2. Thereby, when inserting the catheter 1, friction is reduced, the insertion can be performed smoothly, and operability and safety are improved.

As shown in FIG. 2, the balloon 3 is composed of a tubular membrane member, and is connected (fixed) to the distal end of the catheter body 2 via a tubular connecting member 12. The balloon lumen 11 communicates with the inside of the balloon 3 from the lumen of the catheter body 2 through the lumen of the connecting member 12.

The base end portion of the balloon 3 is airtightly or liquid-tightly fixed to the outer peripheral surface of the distal end portion of the connecting member 12, and the distal end portion of the balloon 3 is the outer peripheral surface of the distal end portion of the inner tube 5 described later. Is fixed in an airtight or liquid-tight manner. These are fixed by, for example, fusion bonding or adhesion with an adhesive.

Each of the balloons 3 is in a state of being collapsed and folded before being expanded (at the time of contraction), but it is expanded by supplying a working fluid therein (FIG. 1).
And the state shown in FIG. 2).

The constituent material of the balloon 3 is composed of various polymer materials (in particular, thermoplastic resin). In this case, the balloon 3 has flexibility as a whole,
It is preferably composed of a material having a relatively small elasticity (elongation).

As the constituent material of the balloon 3, for example,
Polyester resins or polyester elastomers such as polyethylene terephthalate and polybutylene terephthalate, olefin resins such as polyethylene and polypropylene, or those subjected to a crosslinking treatment (particularly those which are crosslinked by electron beam irradiation), vinyl chloride resin, nylon 11, Polyamide resins or polyamide elastomers such as nylon 12, nylon 610, polyurethane resins, ethylene-vinyl acetate copolymers or those obtained by subjecting these to crosslinking treatment, or polymer blends, polymer alloys containing at least one of these Materials include.

Further, the balloon 3 may be constituted by a laminated body in which a plurality of films made of these materials are laminated. In this case, for example, a laminate can be obtained by a method such as coextrusion molding each layer, bonding each layer by adhesion, fusion bonding, or forming another layer by coating on one layer. . Further, a soft resin layer, a layer of a lubricating material, a layer of an antithrombotic material, or the like may be provided on the outside or inside of the layer made of the above material.

The constituent material of the balloon 3 may be mixed with an antithrombotic material such as heparin, prostaglandin, urokinase and arginine derivative.

Inside the balloon 3 and the connecting member 12 (inside), a tubular inner tube 5 is installed and inserted. A guide wire lumen 51 for inserting the guide wire 100 is formed by the inner lumen of the inner tube 5.

The tip portion of the guide wire lumen 51 (inner tube 5) is open at the tip side (tip portion) of the balloon 3, and the base end portion of the guide wire lumen 51 (inner tube 5) is
It is open near the joint between the catheter body 2 and the connecting member 12. That is, the guide wire lumen 51 communicates with the distal end side and the proximal end side of the balloon 3.

The guide wire 100 is inserted into the guide wire lumen 51, the distal end side of the guide wire 100 protrudes from the distal end opening 53 of the guide wire lumen 51, and the proximal end side of the guide wire 100 is guided by the guide wire. It is exposed to the outside of the catheter 1 through the proximal end opening 52 of the lumen 51, and is disposed in the groove 21 substantially parallel to the catheter body 2.

An X-ray opaque marker 6 is provided on the outer peripheral surface of the inner tube 5 to indicate the boundary between the cylindrical portion and the conical portion of the balloon 3 when the balloon 3 is expanded. The X-ray opaque marker 6 is composed of, for example, a fine wire such as gold, silver, platinum, or tungsten, a band, or the like.

Further, as shown in FIG. 4, the base end portion of the inner tube 5 is installed in a state of being inserted into the tip end portion of the groove 21, and the base end portion of the inner tube 5 and the tip end portion of the catheter body 2 are connected to each other. The inner peripheral surface of the base end portion of the connecting member 12 is airtightly or liquid-tightly fixed to the outer peripheral surface of the. With this configuration, the proximal end opening 52 of the guide wire lumen 51 is formed so as to be continuous with the distal end of the groove 21. Thereby, as shown in FIG. 2, the guide wire 100 is arranged so as to extend linearly from the inside of the guide wire lumen 51 into the groove 21, so that the sliding resistance with respect to the catheter 1 is small,
A relative advance / retreat operation between the catheter 1 and the guide wire 100 can be smoothly performed.

The length of the guide wire lumen 51 is not particularly limited, but considering the operability of catheter exchange,
It is preferably about 3 to 30 cm, and more preferably about 7 to 20 cm.

Although the constituent materials of the connecting member 12 and the inner pipe 5 are not particularly limited, a flexible polymer material is preferable, and examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer and ethylene-.
Polyvinyl acetate copolymers, cross-linked ethylene-vinyl acetate copolymers and other polyolefins, polyesters, polyvinyl chloride, polyurethanes, polyamides, polyimides, polyamide elastomers, polyurethane elastomers, polyester elastomers, polyfluororesin and other thermoplastics,
Alternatively, a thermosetting resin or the like may be used.

As shown in FIG. 1, a hub 4 is attached to the proximal end of the catheter body 2. The lumen of the hub 4 communicates with the proximal end of the balloon lumen 11, and a balloon expansion device (not shown) such as a syringe is connected to the hub 4 and the working fluid supplied from the balloon expansion device is connected. Is sent to the inside of the balloon 3 via the balloon lumen 11 or the working fluid is extracted to expand and contract the balloon 3.

A liquid is used as the working fluid for expanding the balloon. This is because the volume of gas decreases when pressure is applied, but the volume of liquid does not change even when pressure is applied. . In addition, the liquid is used from the viewpoint of reducing the pressure loss and safety in case the balloon should burst. Among the liquids, a liquid having an X-ray contrast property is more preferable. For example, a liquid obtained by diluting an X-ray contrast agent such as an arterial contrast agent with physiological saline several times can be used.

The constituent material of the hub 4 is not particularly limited, and examples thereof include resin materials such as polyvinyl chloride, polyethylene, polypropylene, polycarbonate, polymethylmethacrylate, acrylonitrile-styrene-butadiene copolymer, or stainless steel, titanium. Can be made of various metal materials such as

The guide wire 100 is a wire material having bending elasticity, and its constituent material is not particularly limited. For example, various plastics and pseudoelastic (superelastic) alloys (example:
Various metal materials such as Ni-Ti alloy) and stainless steel can be used.

It is preferable that the whole or a part of the surface of the guide wire 100 is subjected to a treatment for imparting lubricity, and the tip end portion thereof is tapered according to the characteristics such as contact resistance and bending resistance. Preferably, the outer diameter is gradually reduced toward the tip. As a result, when the guide wire 100 is inserted into the blood vessel from the distal end side and reaches the target site (coronary artery or the like), the guide wire 100 can be smoothly inserted, and a complicated blood vessel shape such as a curved or branched blood vessel is formed. It is flexible and can be inserted easily and safely.

The catheter 1 and the guide wire 100 as described above are inserted into the guiding catheter 200 for use. As shown in FIG. 3, the guiding catheter 200 is a tubular member whose inner diameter is greater than the outer diameter of the catheter body 2. The constituent material of the guiding catheter 200 is not particularly limited, but, for example, the same constituent materials as those mentioned as the constituent materials of the connecting member 12 and the inner tube 5 can be used.

As shown in FIG. 1, a Y connector 300 is mounted on the proximal end side of the guiding catheter 200. An inner lumen is formed inside the Y connector 300 along the longitudinal direction thereof, the inner lumen communicates with the inner lumen of the guiding catheter 200, and the catheter 1 and the guide wire 100 are guided. It passes through the catheter 200 and the lumen of the Y connector 300 and projects from the proximal end of the Y connector 300.

Further, the Y connector 300 is formed with a tubular branch portion 310. The branch unit 310 is, for example,
It is used to inject an X-ray contrast agent into a desired target site in a blood vessel. The X-ray contrast agent injected from the branch portion 310 is used for the lumen of the Y connector 300 and the guiding catheter 20.
It is discharged from the tip opening of the guiding catheter 200 through the 0 lumen.

Next, a method of using the catheter 1 when applied to the PTCA operation will be described.

[1] The femoral artery (or brachial artery) was punctured with the catheter introducer by the Seldinger method, and the guiding catheter 200 having a guide wire (not shown) inserted through the sheath of the catheter introducer was inserted into the artery. The catheter is inserted into the incision and the guide wire is advanced, and the advancing / retreating and the rotation are repeated until the distal end reaches the coronary artery entrance and is placed.

[2] After removing the guide wire,
The catheter 1 with the guide wire 100 inserted through the groove 21 and the guide wire lumen 51 is attached to the Y connector 30.
0 through the hemostasis valve provided at the proximal opening of the guide wire 100 along the lumen of the guiding catheter 200.
While advancing in the forward direction, the distal end portion of the catheter 1 is projected from the distal end opening of the guiding catheter 200. At this time, in the present invention, as described above,
The catheter 1 can be smoothly and quickly advanced by rotating the catheter 1 as necessary according to the bending condition of the guiding catheter 200 and the blood vessel.

[3] When the tip of the catheter 1 reaches the inside of the coronary artery, the guide wire 100 is rotated and advanced as necessary to pass the tip through the coronary artery stenosis which is the target site. In the present invention, since the guide wire 100 is housed in the groove 21, the guide wire 100 also rotates following the rotation operation of the catheter 1 and does not become entangled with the outer circumference of the catheter body 2 when the catheter 1 is rotated as described above. The operability of the guide wire 100 is also improved. Therefore,
The operation of passing such a guide wire 100 through the coronary artery stenosis can be performed easily and reliably.

During this time, an X-ray contrast agent is injected from the branch portion 310 of the Y connector 300 and supplied into the coronary artery via the Y connector 300 and the lumen of the guiding catheter 200 to perform position confirming contrast.

[4] When the tip of the guide wire 100 passes through the coronary artery stenosis, the advancement of the guide wire 100 is stopped, and then the catheter 1 is slowly advanced along the guide wire 100 to make the radiopaque marker 6 With the clue, the balloon 3 is positioned at the coronary artery stenosis.

Next, the working fluid is injected from the hub 4 and supplied into the balloon 3 through the lumen of the hub 4 and the balloon lumen 11, and the balloon 3 is supplied at 4 to 18 atm, although it depends on the size of the balloon 3. To expand. As a result, the coronary artery stenosis is expanded.

[5] From this state, the already inserted catheter is exchanged with a catheter having a larger balloon suitable for expanding the coronary artery stenosis, for example.

When replacing the catheter 1 inserted in the coronary artery with a new catheter, the guide wire 10
0 and the guiding catheter 200 are left indwelling, the balloon 3 is deflated, the hub 4 is pulled toward the proximal end side, the catheter 1 is retracted, and the catheter 1 is withdrawn. Further, since the proximal end of the guide wire 100 is fixed with fingers or the like, the catheter 1 can be extracted with the guide wire 100 left in the body.

The proximal end of the guide wire 100 is inserted into the distal end hole of a new catheter (balloon catheter or the like) to be replaced, and the catheter is advanced along the guide wire 100. As described above, the Y connector 300 and The target site is reached through the lumen of the guiding catheter 200. This completes the exchange of the catheter. Then, an operation is performed according to the purpose of the exchanged catheter.

<Second Embodiment> FIG. 6 is a perspective view showing a catheter body in a second embodiment of the balloon catheter of the present invention. In the following description, the right side in FIG. 6 is referred to as the “base end” and the left side is referred to as the “tip end”. Further, in FIG. 6, the length of the catheter body 2a in the longitudinal direction is shortened for easy understanding.

The second embodiment of the balloon catheter of the present invention will be described below with reference to this drawing, but the description will focus on the differences from the above-mentioned embodiment, and the description of the same items will be omitted.

In this embodiment, the groove 2 of the catheter body 2a is used.
The depth (maximum depth) of 1 is the same as that of the first embodiment except that the depth (maximum depth) of 1 continuously decreases (gradually decreases) toward the base end direction.

In the catheter body 2a of this embodiment, the depth of the groove 21 is relatively deeper toward the distal end side and relatively shallower toward the proximal end side. As a result, the catheter body 2a
Has a smaller bending rigidity when bent so that the portion where the groove 21 is formed is curved toward the distal end side, and the direction in which the groove 21 is curved toward the inside toward the proximal end side. There is no difference in ease of bending from other directions. As a result, superior followability can be obtained on the distal end side of the catheter main body 2, and excellent torque transmission and pushability can be obtained on the proximal end side of the catheter main body 2a. That is, in this embodiment, more excellent operability can be obtained.

The depth of the groove 21 of the catheter body 2a may be constant along the longitudinal direction.
Further, the depth of the groove 21 may be zero in the middle of the catheter body 2a. That is, the groove 21 may be eliminated in the middle of the catheter body 2a.

<Third Embodiment> FIG. 7 is a perspective view showing a catheter body of a balloon catheter according to a third embodiment of the present invention. In the following description, the right side in FIG. 7 is referred to as the “base end” and the left side is referred to as the “tip end”. Further, in FIG. 7, the length of the catheter body 2b in the longitudinal direction is shortened for easy understanding.

The third embodiment of the balloon catheter of the present invention will be described below with reference to this figure, but the description will be focused on the differences from the above-mentioned embodiment, and the description of the same items will be omitted.

In this embodiment, the groove 2 of the catheter body 2b is used.
1 is the same as that of the first embodiment except that the depth (maximum depth) of 1 gradually decreases (gradually decreases) toward the base end direction.

In the catheter body 2b of this embodiment, the depth of the groove 21 is reduced in a plurality of steps (three steps in the illustrated configuration) toward the proximal direction. That is, the depth of the groove 21 is relatively deep on the distal end side of the catheter body 2b, the depth of the groove 21 is relatively shallow on the proximal end side, and the groove depth is medium at the intermediate portion thereof. As a result, in this embodiment, the same effect as in the second embodiment can be obtained.

The balloon catheter of the present invention has been described above with reference to the illustrated embodiment, but the present invention is not limited to this, and each part constituting the balloon catheter can exhibit any desired function. It can be replaced with that of the configuration.

[0086]

As described above, according to the present invention, with a simple structure, excellent torque transmission and pushability, and
A balloon catheter having excellent operability and excellent followability can be obtained.

When at least a part of the guide wire can be inserted into the groove of the catheter body, it can be used in combination with a guiding catheter having a smaller diameter, so that it can be inserted into a thinner blood vessel. it can.

When the groove of the catheter body is formed by plastically deforming the tube wall of the catheter body, the manufacturing is easy and the above effect can be achieved at a lower manufacturing cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a balloon catheter according to a first embodiment of the present invention is inserted into an inner cavity of a guiding catheter.

FIG. 2 is a vertical cross-sectional view of the distal end portion of the catheter shown in FIG.

3 is a sectional view (transverse sectional view) taken along line XX in FIG.

FIG. 4 is a sectional view (transverse sectional view) taken along line YY in FIG.

5 is a perspective view of a catheter body of the catheter shown in FIG. 1. FIG.

FIG. 6 is a perspective view showing a catheter body in a second embodiment of the balloon catheter of the present invention.

FIG. 7 is a perspective view showing a catheter body in a third embodiment of the balloon catheter of the present invention.

FIG. 8 is a graph showing measured data of load and bending amount in a three-point bending test of a metal tube on the vertical axis and the horizontal axis, respectively.

[Explanation of symbols]

1 catheter 11 balloon lumens 12 Connection member 2, 2a, 2b catheter body 21 groove 22 Projection 3 balloons 4 hubs 5 inner tube 6 X-ray opaque marker 51 guide wire lumen 52 Base end opening 53 Tip opening 100 guide wire 200 guiding catheter 300 Y connector 310 Branch

Claims (7)

[Claims] 1. A tubular catheter main body made of a metal material, an expandable / contractible balloon installed on the distal end side of the catheter main body, and an inner cavity of the catheter main body, which communicates with the inside of the balloon. And a guide wire lumen that is formed so as to be opened to the distal end side of the balloon and surrounded by a tube wall inside the balloon, and that inserts a guide wire from the distal end side of the balloon to the outside of the catheter body. In the balloon catheter, the catheter body has a groove formed along the longitudinal direction on the outer peripheral surface of at least the distal end side portion thereof so as to dent the tube wall, The balloon catheter, wherein the wall thickness of the tube wall is substantially constant over the entire circumference including the groove forming portion. 2. The balloon catheter according to claim 1, wherein the groove is formed over substantially the entire length of the catheter body. 3. The balloon catheter according to claim 1, wherein the groove has a portion in which the depth of the groove decreases continuously or stepwise in the proximal direction. 4. The balloon catheter according to claim 1, wherein at least a part of the guide wire can be inserted into the groove. 5. The balloon catheter according to claim 1, wherein the proximal end opening of the guide wire lumen is formed so as to be continuous with the distal end of the groove. 6. The balloon catheter according to claim 1, wherein the balloon has an inner tube inserted through the balloon, and the guide wire lumen is formed by the inner lumen of the inner tube. . 7. The balloon catheter according to claim 1, wherein the catheter body is made of stainless steel or pseudoelastic alloy.