JP2000217923A - Balloon catheter and its fabrication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon catheter which makes easily, being easy to thin out the outer diameter of a catheter tube, having no step in the outer form from a near position end to a distant position end of the catheter tube, and being excellent in the characteristics of inserting the balloon catheter and in the characteristics of pushing, which is hard to kink. SOLUTION: A balloon catheter 2 has an outer tube 6, a balloon part 4 and an inner tube 12. In the outer tube 6, at least one of the lumens for balloon expansion 10 is formed along the longer direction, and the distant position end part of outer tube 6 is joined with the near position end part of balloon part 4. The lumen for balloon expansion 10 is connected to the inside of the balloon part 4. As the space for expansion, which is sealed, is formed inside the balloon part 4, the distant positional end part of the balloon part 4 is joined to a distant position end part of the inner tube 12. The inner tube 12 stretches in the inside of the balloon part 4 and the inside of the lumen for balloon expansion in the outer tube 6. A near position end opening part 22 of the inner tube 12 goes through the tube wall that locates at part of the way in the longer direction of the outer tube 6 and opens to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a balloon catheter suitably used as, for example, a balloon catheter for dilating blood vessels, and more particularly to an improvement of a so-called monorail type balloon catheter.

[0002]

2. Description of the Related Art In recent years, medical technology has tended to move toward minimally invasive treatment. For example, stenosis of the coronary arteries is increasingly being treated with a vasodilating balloon catheter, replacing previous coronary artery bypass surgery. This method of treatment is becoming increasingly applicable in order to greatly reduce the burden on the patient, together with its economic advantages.
At the same time, there is a need for a more efficient and simple structure of a balloon catheter used for simple dilation of coronary stenosis.

[0003] In order to treat a stenosis in a blood vessel, the stenosis is inserted into the blood vessel, the balloon is inflated to expand the stenosis, and the blood flow on the peripheral side of the stenosis is improved.
As a so-called PTCA balloon catheter, there are an over-the-wire balloon catheter and a monorail balloon catheter. In any of these types of balloon catheters, a guide wire is first passed through the stenosis in the blood vessel, and then the balloon catheter is sent to the stenosis along the guide wire, and the balloon is inflated to inflate the stenosis. To expand. At that time, the dilation of the stenosis needs to be performed stepwise so as not to damage the blood vessel, and at first, insert a balloon catheter with a balloon part with a small outer diameter along the guide wire,
The balloon catheter is sequentially replaced with a balloon catheter having a larger outer diameter balloon portion.

In an over-the-wire balloon catheter, a guide wire lumen is formed over the entire length of the catheter tube, a guide wire is inserted through the lumen, and a balloon portion is formed along the guide wire. Guide to the stenosis. Then, after performing a blood vessel dilation with a balloon catheter having a balloon portion having a smaller outer diameter, the balloon catheter is replaced with a balloon catheter having a balloon portion having a larger outer diameter. At that time, since the balloon catheter is withdrawn along the guide wire, it is necessary that the proximal end of the guide wire extends to the outside of the body for more than the entire length of the catheter tube. Otherwise, the balloon catheter cannot be replaced while leaving the distal end of the guidewire in the stenosis.

On the other hand, for example, Japanese Patent Application Laid-Open No. Sho 63-28
In the monorail type balloon catheter disclosed in JP-A-8167 and JP-A-2-307479, an opening is formed in the middle of the catheter tube, and the opening is formed from the opening through the guide wire insertion lumen to the distal end of the balloon. Leading. Therefore, in this type of balloon catheter, the length of the guide wire extending outside the body for replacement of the balloon catheter may be slightly longer than the length corresponding to the length from the opening to the distal end of the balloon. , Compared to other systems. Therefore, the operability is excellent.

Further, such a monorail type balloon catheter is disclosed in US Pat. No. 4,762,129, US Pat.
No. 276411 and JP-A-6-506124.

[0007]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open
In the balloon catheter disclosed in JP-A-288167 and JP-A-2-307479, a portion from the proximal end to the distal end of the catheter tube is constituted by a double-lumen tubular member having two lumens, and in the middle of one lumen. Is sealed with an adhesive or the like, and a side hole is opened at a distal end side of the sealing portion to form a monorail type guide wire insertion lumen. Therefore, there is an unnecessary lumen that does not pass through the guide wire inside the catheter tube at the proximal end side of the side hole, which causes an increase in the outer diameter of the catheter tube.

Further, the sealing portion near the side hole formed in the middle of the double-lumen catheter tube needs to be sealed by injecting an adhesive or by pushing in an appropriate plug or the like. Not easy to manufacture.
Further, the catheter tube has a problem that the catheter tube is hard at the sealing portion, and the bending rigidity changes abruptly at the opening portion of the adjacent side hole, so that the catheter tube is easily kinked (bent). Such a phenomenon becomes more pronounced when the reinforcing rod is inserted into the inside of the catheter tube from the sealing portion toward the proximal end, and the catheter tube is more likely to kink. This is because stress tends to concentrate on the notch opening.

In the balloon catheter disclosed in US Pat. No. 4,762,129, an expansion tubular member formed with a balloon expansion lumen and a wire tubular member formed with a guide wire insertion lumen are axially connected. The proximal end neck portion of the balloon portion is joined so as to overlap at a predetermined distance along and along a part of the overlapping portion. But,
In the balloon catheter disclosed in this publication, the outer diameter of the expanding tubular member extending from the proximal end to the proximal end of the balloon portion is extremely thin as compared with the overlapping portion with the wire tubular member, and the kink is easily kinked. Have.

In the balloon catheter disclosed in US Pat. No. 5,061,273, an expansion tubular member having a balloon expansion lumen formed at a position closer to the proximal end than the proximal end of the balloon portion. And a tubular member for a wire, on which a guide wire insertion lumen is formed, is overlapped at a predetermined distance in the axial direction. For this reason, the outer diameter of the overlapping portion becomes large, and there is a problem in the insertion characteristics. If the outer diameter of the expansion tubular member located at a position closer to the proximal end than the overlapping portion is reduced in order to reduce the outer diameter of the overlapping portion, there is a problem in that kink is also likely to occur.

Further, in the balloon catheter disclosed in JP-A-9-276411 and JP-A-6-506124, the ends of two tubular members constituting a catheter tube are covered with another tubular member. As a result, the outer diameter of the portion becomes large in a step-like manner, and there is a problem in ease of insertion of the balloon catheter.

[0012] Furthermore, Japanese Patent Publication No. 9-503411 discloses that a reinforcing rod is disposed between the proximal end of the catheter tube and the proximal end of the balloon portion in order to improve the pushing characteristics of the catheter tube. A balloon catheter having a distal end fixed to a catheter tube has been proposed. However, this balloon catheter has a problem that it is difficult to push the balloon catheter into a complicated and meandering blood vessel because the flexibility of the distal end portion of the catheter tube is reduced.

The present invention has been made in view of such circumstances, is easy to manufacture, easily reduces the outer diameter of the catheter tube, and has no step in the outer shape from the proximal end to the distal end of the catheter tube. An object of the present invention is to provide a balloon catheter having excellent insertion characteristics of a balloon catheter and excellent push-in characteristics that are not easily kinked.

[0014]

In order to achieve the above object, a balloon catheter according to the present invention comprises an outer tube having at least one lumen for expanding a balloon formed along a longitudinal direction, and A proximal end portion of the balloon portion joined to the distal end portion, a balloon portion communicating with the balloon inflation lumen, and a balloon portion so as to form a sealed inflation space inside the balloon portion; A distal end of the inner tube joined to a distal end of the inner tube, the inner tube having an inner tube extending axially inside the balloon portion and inside the balloon expansion lumen of the outer tube; A proximal end opening of the tube is characterized by being open to the outside through a tube wall located halfway in the longitudinal direction of the outer tube.

A proximal end opening of the inner tube, wherein the proximal end opening of the inner tube is open to the outside through a tube wall positioned halfway in the longitudinal direction of the outer tube; It is preferable that the outer tube and the tube wall are heat-sealed airtightly.

[0016] The outer tube may have a circular cross section over its entire length in the longitudinal direction. In this case, in the present invention, the outer diameter does not necessarily have to be uniform along the longitudinal direction of the outer tube, and may be uneven. For example, the outer tube may be a tapered tube whose outer diameter decreases from any position on the proximal end side to any position on the distal end side of the outer tube.

Alternatively, the outer tube has a first outer tube member and a second outer tube member joined to a proximal end of the first outer tube member, and a proximal end opening of the inner tube is provided. The portion may be open to the outside through a tube wall positioned in the longitudinal direction of the first outer tube member. In this case, the second outer tube member is made of a different material or a different material such that the flexural rigidity (EI; E is the Young's modulus of the material, I is the second moment of area) is higher than that of the first outer tube member. Preferably, they have different cross-sectional shapes.

For example, the second outer tube member may be made of a material having a higher hardness than the first outer tube member, or only the second outer tube member may contain a reinforcing material (including adherence). Is also good. Alternatively, the second outer tube member may be a tapered tube in which the outer diameter is tapered from the distal end toward the proximal end. Further, only the second outer tube member may have an irregular cross section other than the circular cross section. In this case, in the joint portion between the first outer tube member and the second outer tube member, the second outer tube member is made to have a second outer tube member having the same cross-sectional shape as the first outer tube member. The cross-sectional shape of the tube member is such that it gradually changes from a deformed cross section to a circular cross section toward the joint.

[0019] The method for manufacturing a balloon catheter according to the present invention includes the step of: attaching the proximal end of the balloon portion to the distal end of an outer tube having at least one lumen for balloon expansion formed along the longitudinal direction. A balloon portion proximal end joining step of joining the balloon inflation lumen and the inside of the balloon portion so as to communicate with each other, and axially moving the inner tube to the inside of the balloon portion and the inside of the balloon inflation lumen of the outer tube. Drawing out a proximal end portion of the inner tube to the outside of the outer tube through a through hole formed in a tube wall positioned in the axial direction of the outer tube, and a tube of the outer tube. A heat welding step of heat-sealing an outer tube wall of the inner tube located at a portion passing through a through-hole formed in a wall and an inner edge of the through-hole; Removing an unnecessary portion of the inner tube located outside from the heat-sealed portion, leaving a heat-sealed portion between the outer tube wall of the inner tube and the inner edge of the through hole, which are heat-sealed in the step; Removing the proximal end opening of the inner tube to the tube wall of the outer tube; and forming the distal end of the inner tube to form a sealed expansion space inside the balloon portion. Joining to the distal end of the part.

In the method of manufacturing a balloon catheter according to the present invention, it is preferable that, in the heat-sealing step, a heat-sealing tube is used, a portion to be heat-sealed be covered with the heat-sealing tube, and heated. After heat fusion, it is preferable to remove the heat sealing tube. The heat seal tube is not particularly limited, but for example, a fluorine resin tube or the like is used.

[0021]

In the balloon catheter according to the present invention, only the distal end of the balloon catheter adopts a so-called coaxial catheter tube structure composed of an outer tube and an inner tube, and the lumen of the inner tube is inserted through a guide wire. We use as lumen. For this reason, the balloon catheter according to the present invention has an outer diameter of the catheter tube in comparison with a conventional balloon catheter having a so-called double-lumen catheter tube (Japanese Patent Laid-Open Nos. 63-288167 and 2-307479). Is easy to make thin. Further, in the balloon catheter according to the present invention, compared to a balloon catheter having a double-lumen catheter tube, there is no need to form a sealing portion for closing one lumen near the side hole, so that the manufacture is easy. . Furthermore, in the balloon catheter according to the present invention, the proximal end opening of the inner tube serving as the proximal end side outlet of the guide wire is opened to the outside through the tube wall located in the middle of the outer tube in the longitudinal direction. The opening has a double structure of an inner tube and an outer tube, and has a structure that is difficult to kink.

Further, in the balloon catheter according to the present invention, the proximal end opening of the inner tube, which serves as the proximal end side outlet of the guide wire, penetrates the tube wall located in the middle of the outer tube in the longitudinal direction and is connected to the outside. Since there is no need to make a step over the entire length of the catheter tube, the balloon catheter has excellent insertion characteristics. In addition, since it has a structure that does not easily kink, the balloon catheter has excellent pushing characteristics.

If necessary, a reinforcing rod extending to the vicinity of the proximal end opening of the inner tube may be arranged on the proximal end side of the outer tube constituting the catheter tube. In this case, it is preferable that the distal end of the reinforcing rod is disposed at a position of about 1 to 10 cm on the distal end side beyond the opening. With this configuration, the catheter tube
The structure becomes difficult to kink.

Alternatively, the rigidity of the outer tube constituting the catheter tube is made higher in the range from the vicinity of the opening of the proximal end of the inner tube to the proximal end of the outer tube than the rigidity of the other distal end of the outer tube. As described above, a reinforcing material may be incorporated, ions may be implanted, or a polymer resin may be precipitated. Further, the outer tube includes a relatively flexible distal end first outer tube member and a relatively rigid proximal end second outer tube member joined to the first outer tube. May be. In these cases, the push-in characteristics of the balloon catheter are further improved, and the distal end side of the catheter tube becomes flexible, so that the insertion characteristics in a body cavity such as a meandering blood vessel are further improved.

In the present invention, when the outer tube is constituted by a first outer tube member having a circular cross section and a second outer tube member having a modified cross section joined to a proximal end portion of the first outer tube member. Has the following effects. That is,
When the cross section of the outer tube on the proximal end side becomes an elliptical cross section, for example, when inserting two or more balloon catheters into a blood vessel at the same time, as in the kissing method,
The balloon catheter according to the present invention can be conveniently inserted into a narrow blood vessel without imposing a burden on the blood vessel.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings. FIG. 1A is an overall configuration diagram of a balloon catheter according to one embodiment of the present invention, and FIG.
Is a sectional view taken along the line IB-IB shown in FIG.
Is a cross-sectional view taken along the line IC-IC shown in FIG.
1 is a sectional view taken along the line ID-ID shown in FIG.
FIG. 3 is a longitudinal sectional view of a main part of the balloon catheter shown in FIG.
FIG. 3A is a perspective view of an outer tube and a balloon portion showing a manufacturing process of the balloon catheter according to the present embodiment, and FIG.
(B) is a perspective view of the tube for heat sealing used in the manufacturing process of the balloon catheter, FIG. 4 (A), FIG. 4 (B),
5 (A) and 5 (B) are perspective views of a main part showing a manufacturing process of the balloon catheter, and FIGS. 6 and 7 (A) to 7 (C).
FIG. 2 is a schematic perspective view and a cross-sectional view of a main part showing a use state of the balloon catheter.

First Embodiment A balloon catheter 2 according to this embodiment shown in FIG.
For example, percutaneous coronary angioplasty (PTCA), dilation of blood vessels such as limbs, dilation of the upper ureter, renal vasodilation, etc. are used to dilate a stenosis formed in a blood vessel or other body cavity. Used to In the following description,
A case where the balloon catheter 2 of the present embodiment is used for PTCA will be described as an example.

The balloon catheter 2 for expansion according to the present embodiment
Is a so-called monorail type balloon catheter, which has a balloon portion 4, an outer tube 6 as a catheter tube, and a connector 8.

The balloon portion 4 shown in FIGS. 1 and 2 is formed of a cylindrical film having both ends reduced in diameter.
Although not particularly limited, 15 to 300 μm, preferably 3
0 to 150 μm. The balloon portion 4 is not particularly limited as long as it is cylindrical, and may have a cylindrical or polygonal cylindrical shape.
The outer diameter of the balloon portion 4 at the time of expansion is determined by factors such as the inner diameter of a blood vessel, and is usually about 1.5 to 10.0 mm, preferably 3 to 7 mm. The length of the balloon portion 4 in the axial direction is determined by factors such as the size of the intravascular stenosis, and is not particularly limited.
m, preferably 20 to 40 mm. The balloon portion 4 before being expanded is folded and wound around the inner tube 12, and has an outer diameter as small as possible.

The material constituting the balloon portion 4 is preferably a material having a certain degree of flexibility. For example, ethylene such as polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer and other α-olefins may be used. Copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride (PVC), cross-linked ethylene-vinyl acetate copolymer, polyurethane, polyamide,
Polyamide elastomer, polyimide, polyimide elastomer, silicone rubber, natural rubber, etc. can be used,
Preferred are polyethylene, polyethylene terephthalate and polyamide.

As shown in FIG. 2, a proximal end 5 of the balloon portion 4 is joined to the outer periphery of the distal end of the outer tube 6 by means such as heat fusion or adhesion. The first lumen 10 communicates with the internal expansion space of the balloon section 4. The distal end portion 7 of the balloon portion 4 is joined to the outer periphery of the distal end portion of the inner tube 14 by means such as heat fusion or adhesion, and the internal expansion space of the balloon portion 4 is the first lumen. Other than 10, it is sealed to the outside. The first lumen 10 of the outer tube 6 feeds a fluid into the internal expansion space of the balloon portion 4 to expand the balloon portion 4 or to extract fluid from the expansion space of the balloon portion 4 to contract the balloon portion 4. It is a passage.

As shown in FIG. 2, the inner tube 12 extends coaxially and axially in the expansion space of the balloon portion 4 and the inside of the distal end side first lumen 10 of the outer tube 6, and has a so-called coaxial catheter. It has a tube structure. A contrast ring 15 is attached to the outer periphery of the inner tube 12 located inside the balloon portion 4. When the balloon catheter 2 is inserted into a living body, the position of the contrast ring 15 is detected by X-rays or the like from outside the living body. Imaging is possible. Examples of the material of the contrast ring 15 include metals such as gold, platinum, and tungsten.

A second lumen 14 is formed inside the inner tube 12, and its distal end opening 20 opens at the distal end 7 of the balloon portion 4. The proximal end opening 22 of the inner tube 12 is opened to the outside through a through-hole 21 of a tube wall located in the middle of the outer tube 6 in the longitudinal direction. The peripheral edge of the proximal end opening 22 of the inner tube 12 and the peripheral edge of the through hole 21 in the tube wall of the outer tube 6 are hermetically joined by a heat fusion method described later. The shape of the proximal end opening 22 of the inner tube 12 is not particularly limited, and may take various shapes such as a circle and an ellipse. In the present embodiment, as shown in FIG. It is an elliptical shape with the part cut diagonally. Inner tube 12
The second lumen 14 is a guide wire insertion lumen through which a guide wire 42 shown in FIG. 2 for guiding the balloon catheter 2 into a body cavity is inserted. Guide wire 4
2 is composed of a single wire or a stranded wire of, for example, stainless steel, copper, copper alloy, titanium, titanium alloy, etc., and its outer diameter is not particularly limited.
mm, more preferably 0.25 to 0.6 mm.

In the present embodiment, the outer tube 6 is provided as shown in FIG.
As shown in (A) to (D), the first outer tube member 6a has the same outer diameter and inner diameter with a circular cross section all over the entire length.

The first outer tube member 6a may be made of, for example, the same material as that of the balloon portion 4, but is preferably made of a material having flexibility, for example, polyethylene, polyethylene terephthalate, polypropylene, ethylene-ethylene. Uses propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride (PVC), cross-linked ethylene-vinyl acetate copolymer, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, silicone rubber, natural rubber, etc. Preferably, it is made of polyethylene, polyamide, or polyimide.

The soft synthetic resin constituting the first outer tube member 6a is preferably a polyurethane, polyamide, polyimide, polyethylene or the like having a JIS hardness of 50.
About A to 90 A can be used.

The inner tube 12 can be made of a soft synthetic resin of the same material as the first outer tube 6a.
The first outer tube 6a may be made of a synthetic resin that is harder than the first outer tube 6a. The position where the proximal end opening 22 of the inner tube 12 opens outside the first outer tube member 6a is preferably a position of a length L1 from the distal end of the first outer tube member 6a, and the length L1 Is preferably 150 to 350 mm, more preferably 200 to 300 mm. Also, the first
The outer diameter of the outer tube member 6a is not particularly limited, but is preferably 0.5 to 5 mm, and more preferably 0.5 to 1 mm.
mm. The thickness of the first outer tube member 6a is not particularly limited, but is preferably 0.05 to 0.5 mm, and more preferably 0.1 to 0.2 mm.

The outer diameter of the inner tube 12 is determined so that a gap is formed between the inner tube 12 and the first outer tube member 6a, and is not particularly limited, but is preferably 0.3 to 3 mm, more preferably 0.3 to 3 mm. 0.8 mm. Inner tube 12
Is not particularly limited as long as it can penetrate the guide wire 42, and is, for example, 0.15 to 1.0 mm, and preferably 0.25 to 0.6 mm.

The pressure fluid introduced into the first lumen 10 through the port of the connector 8 is not particularly limited.
A 0/50 mixed aqueous solution is used. The reason for including the radiopaque medium is to image the positions of the balloon portion 4 and the outer tube 6 using radiation when the balloon catheter 2 is used. The pressure of the pressure fluid for inflating the balloon portion 4 is not particularly limited, but is about 3 to 12 atm, preferably about 4 to 18 atm in absolute pressure.

In this embodiment, in order to reinforce the strength of the first outer tube member 6a from the vicinity of the opening 22 to the proximal end side, as shown in FIG.
It may be disposed inside the first outer tube member 6a from the vicinity to the proximal end side. The proximal end of the reinforcing rod 28 has a circular cross-section, tapers from the middle toward the distal end, and has a cross-sectional shape at the distal end such that the reinforcing rod 28 has a flat cross-sectional shape. It is changing gradually. The distal end of the reinforcing rod 28, which has a flat cross-section, slightly (preferably 1) with the proximal end opening 22 of the inner tube 12, as shown in FIG.
(About 10 cm) at a position over the inner wall of the first outer tube member 6a by means of heat fusion or adhesion.

The reinforcing rod 28 is made of stainless steel,
It is made of a metal material such as copper, copper alloy, titanium, and titanium alloy, or a synthetic resin such as polyimide, polyamide, and polyethylene terephthalate. The maximum outer diameter of the reinforcing rod 28 is determined so as not to block the lumen 10 of the first outer tube member 6a, and is not particularly limited, but is preferably 0.3 to 0.6 mm.

In this embodiment, the first outer tube member 6a
It is preferable that a coating material made of a hydrophilic polymer substance having lubricity in a wet state is coated on the outer periphery of the outer tube 6 composed of the following. By covering the outer periphery of the outer tube 6 with such a covering material, it is possible to reduce insertion resistance when the balloon catheter 2 is inserted into a blood vessel or the like. The outer periphery of the balloon 4 may be covered with a coating material. However, the balloon portion 4 expands a stenotic portion such as a blood vessel. When the stenotic portion is expanded, the balloon portion slides on the stenotic portion. Is not always preferred. Therefore, in the present embodiment, only the outer periphery of the outer tube 6 is covered with a coating material made of a hydrophilic polymer substance.

As the hydrophilic polymer, there are a natural polymer and a synthetic polymer. Examples of natural polymers include starch, cellulose, tannin / nignin, polysaccharide, and protein. Synthetic polymers include PVA, polyethylene oxide, acrylic acid, maleic anhydride,
Examples include phthalic acid-based, water-soluble polyester, ketone aldehyde resin, (meth) acrylamide-based, vinyl heterocyclic, polyamine-based, polyelectrolyte, water-soluble nylon-based, and glycidyl acrylate-based.

Among these, hydrophilic polymer substances that can be suitably used as a coating material for the outer tube 6 include, in particular, cellulose-based polymer substances (eg, hydroxypropylcellulose) and polyethylene oxide-based polymer substances (eg, Polyethylene glycol), maleic anhydride-based polymer (for example, maleic anhydride copolymer such as methyl vinyl ether-maleic anhydride copolymer), acrylamide-based polymer (for example, polydimethylacrylamide), water-soluble nylon (for example, Toray) AQ-nylon P-70) or a derivative thereof is preferred because a low coefficient of friction can be stably obtained.

Next, a method for manufacturing the balloon catheter 2 according to this embodiment will be described. As shown in FIG. 3A, first, a first outer tube member 6a and a balloon portion 4 are prepared, and a cylindrical proximal end portion of the balloon portion 4 is provided on the outer periphery of a distal end of the first outer tube 6a. 5 and heat-sealing the portion. Next, a through-hole 21 is formed in the tube wall at a predetermined position in the axial direction of the first outer tube member 6a so that the inner tube 12 described later can pass through. Also, a heat sealing tube 50 shown in FIG. 3B is prepared. The inner diameter of the heat sealing tube 50 is slightly larger than the outer diameter of the first outer tube member 6a. As the tube 50 for heat sealing, for example, a fluororesin tube is used, and its axial length is, for example, about 20 mm. At one axial end of the heat sealing tube 50,
A cut 52 having a length of about 3 mm is formed.

Next, as shown in FIG. 4A, the inner tube 12 to which the contrast ring 15 is attached is prepared, and the inner tube 12 is integrated into the lumen of the inner tube 12 through the wire-shaped mandrel 54. The inner tube 12 with the mandrel 54 integrated therethrough is passed through the through-hole 21 into the inner lumen of the first outer tube member 6a, and the distal end of the inner tube 12 is projected from the distal end 7 of the balloon portion 4 to enhance contrast. The ring 15 is located at the center of the balloon section 4. Before and after that, the heat sealing tube 50 is positioned on the outer periphery of the first outer tube member 6a.

Thereafter, a heat sealing mandrel 56 is inserted into the inside from the proximal end of the first outer tube member 6a.
The distal end of the mandrel 56 is positioned near the through hole 21 to prevent the first outer tube 6a from being crushed near the through hole 21. The proximal end of the mandrel 56 has an outer diameter that is substantially equal to or less than the inner diameter of the first outer tube member 6a,
An axial recess 57 is formed at the distal end so as to receive the outer periphery of the inner tube 12. Next, the heat-sealing tube 50 is moved in the axial direction around the outer periphery of the first outer tube member 6 a, and the heat-sealing tube 50 is moved to the outer periphery of the first outer tube 6 a near the through hole 21 and the through hole 2.
The outer surface of the inner tube 12 that protrudes from the outer tube 1 is integrally covered. Then, using a mold for heat sealing,
Pressing and heating is performed from the outside of the heat sealing tube 50 to thermally fuse the hole edge of the through hole 21 and the outer tube wall of the inner tube 12. The heating temperature is not particularly limited, but is preferably 1
00 to 300 ° C, particularly preferably 150 to 250 ° C
It is.

Thereafter, the mandrels 54 and 56 are taken out, and the notches 5 of the heat sealing tube 50 are cut out.
2 to tear the tube 50 in the axial direction,
Is removed from the outer periphery of the first outer tube 6a. After that, as shown in FIGS. 5A and 5B, the heat-sealed portion between the outer tube wall of the inner tube 12 and the inner edge of the through-hole 21 that has been heat-sealed in the heat-sealing step is left. Unnecessary portions of the inner tube 12 located outside the fused portion are cut and removed with a cutter or the like. As a result, the proximal end opening 22 of the inner tube 12
Are formed outside the tube wall of the first outer tube member 6a. The proximal end opening 22 has a substantially elliptical shape in this example. However, in FIG. 5, although the ellipse is quite flat, it is actually an ellipse close to a circle. In addition,
Before or after these steps, or at the same time, the distal end of the inner tube 12 shown in FIG. 4A is heat-sealed to the distal end of the balloon 4 by a similar heat sealing method.
It is cut to a predetermined length.

Thereafter, the connector 8 shown in FIG. 1 is joined to the proximal end of the first outer tube member 6a by means such as heat fusion. Thereafter, if necessary, the outer peripheral surface of the outer tube 6 is coated with a coating material made of a hydrophilic polymer substance having lubricity in a wet state, and the balloon catheter 2 shown in FIG. 1 is obtained.

Next, a method of performing PTCA treatment using the balloon catheter 2 of the embodiment shown in FIG. 1 will be described. First, air in the balloon catheter 2 is removed as much as possible. Therefore, a suction / injection means such as a syringe is attached to the port of the connector 8, a liquid such as a blood contrast agent (for example, containing iodine) is put into the syringe, and suction and injection are repeated, and the third lumen 24, the first lumen The air in 10 and the balloon section 4 is replaced with a liquid.

In order to insert the balloon catheter 2 into the arterial blood vessel, first, a guide wire for a guide catheter (not shown) is inserted into the blood vessel by the Seldinger method or the like so that the distal end thereof reaches, for example, near the heart. I do. Then, along the guide wire for the guide catheter, FIG.
Is inserted into the arterial blood vessel 34 and the distal end thereof is positioned at the coronary artery entrance 40 of the heart 38 having the stenosis 36. The stenosis part 36 is formed by, for example, thrombus or arteriosclerosis.

Next, only the guide wire for the guide catheter is withdrawn, a guide wire 42 for the balloon catheter thinner than that is inserted along the guide catheter 32, and the distal end thereof is inserted to a position where it passes through the stenosis portion 36.

Thereafter, the distal end of the guide wire 42 is inserted into the distal open end 20 of the balloon catheter 2 shown in FIG. 1, passed through the first lumen 14, and pulled out from the proximal end opening 22. Then, with the balloon section 4 folded, the balloon catheter 2 is passed through the guide catheter 32 shown in FIG. Then, as shown in FIG. 6, the balloon portion 4 of the balloon catheter 2 is inserted to a position just before the stenosis portion 36.

Thereafter, as shown in FIGS. 7A and 7B, the folded balloon portion 4 of the balloon catheter 2 is inserted between the stenotic portions 36 along the guide wire 42.

Next, as shown in FIG. 7C, the balloon portion 4 is accurately positioned at the center of the stenosis portion 36 while observing the position of the balloon portion 4 with an X-ray fluoroscope or the like. By inflating the balloon portion 4 at that position, the stenotic portion 36 of the blood vessel 32 can be widened, and good treatment can be performed. In order to inflate the balloon portion 4, the third lumen 24 and the first lumen 1 are connected through the port of the connector 8 shown in FIG.
This is performed by injecting a liquid into the balloon portion 4 through the “0”.

The expansion time is not particularly limited, but is, for example, about 1 minute. Thereafter, the liquid is quickly drained from the balloon portion 4 to deflate the balloon portion, thereby securing the blood flow on the peripheral side of the dilated stenosis portion 36. The expansion of the stenosis part 36 must be performed stepwise so as not to damage the blood vessel 34. First, the balloon catheter 2 having the balloon part 4 with a small outer diameter is inserted along the guide wire 42, and then the balloon catheter 2 is sequentially enlarged. The balloon catheter 2 having a balloon portion 4 having a diameter is exchanged. At that time, since the balloon catheter 2 according to the present embodiment is a monorail type balloon catheter, the proximal end of the guide wire 42 is slightly longer than a portion corresponding to the length of the inner tube 12. The balloon catheter can be exchanged simply by extending it outward.

In the balloon catheter 2 according to the present embodiment, only the distal end of the balloon catheter 2 adopts a so-called coaxial catheter tube structure composed of the outer tube 6 and the inner tube 12. The lumen 14 is used as a guide wire insertion lumen. For this reason, a conventional balloon catheter having a so-called double-lumen catheter tube (Japanese Unexamined Patent Publication No.
The balloon catheter 2 according to the present embodiment is compared with Japanese Patent Application Laid-Open No. 3-288167 and Japanese Patent Application Laid-Open No. 2-307479.
Then, the outer diameter of the outer tube 6 can be easily reduced. Further, in the balloon catheter 2 according to the present embodiment, compared to a balloon catheter having a double-lumen catheter tube, there is no need to form a sealing portion for closing one lumen near the side hole, so that its manufacture is easy. It is. further,
In the balloon catheter 2 according to the present embodiment, the proximal end opening portion 22 of the inner tube 12 serving as the proximal end side outlet of the guide wire penetrates a tube wall located in the longitudinal direction of the outer tube 6. It is open to the outside, and the opening 22 has a double structure of the inner tube 12 and the outer tube 6, and has a structure that is difficult to kink.

Further, in the balloon catheter 2 according to the present embodiment, the proximal end opening 22 of the inner tube 12 serving as the proximal end side outlet of the guide wire 42 is connected to the outer tube 6.
Only penetrates the tube wall located in the middle of the longitudinal direction of the catheter tube 2 and is opened to the outside. There is no need to make a step over the entire length of the catheter tube 2, and the balloon catheter 2 has excellent insertion characteristics. In addition, since it has a structure that does not easily kink, the balloon catheter 2 has excellent pushing characteristics.

In this embodiment, as shown in FIG. 2, the reinforcing rod 28 is disposed inside the first outer tube member 6a on the proximal end side from the vicinity of the opening 22. The pushing characteristics are further improved, and the distal end side of the catheter tube becomes flexible, so that the insertion characteristics in a body cavity such as a meandering blood vessel are further improved.

In this embodiment, the reinforcing rod 28
Although it is not always necessary, it is better to improve the insertion characteristic (push-in characteristic) in a body cavity such as a meandering blood vessel. From the same point of view, without arranging the reinforcing rod 28, in the range from the vicinity of the proximal end opening 22 of the inner tube 12 to the proximal end of the outer tube 6, the other distal end portion of the outer tube 6 In order to increase the rigidity of the first outer tube member 6a, a reinforcing material may be built in the proximal end side of the first outer tube member 6a, ions may be implanted, or a polymer resin may be precipitated. Alternatively, when the first outer tube member 6a is formed by extrusion or the like, the hardness is increased toward the proximal end side so that the hardness is increased at the proximal end side even if the cross-sectional shape is the same in the axial direction. May be realized. As described above, by using the outer tube 66 having a higher rigidity on the proximal end side of the outer tube 6, the pushing characteristics of the balloon catheter 2 are improved, and the distal end side of the catheter tube becomes flexible, so that the tortuous blood vessel is formed. For example, the insertion characteristics in a body cavity, such as the above, are further improved.

Second Embodiment In the above-described embodiment, the outer tube 6 is constituted by a single first outer tube member 6a along the axial direction. However, in the present invention, the outer tube 6 is formed along the axial direction. You may comprise two or more tubes.

FIGS. 8A to 8D show a balloon catheter 2B according to still another embodiment, in which the outer tube 6B is a relatively flexible first outer tube member 6a.
And a second outer tube member 6c having relatively high rigidity which is joined to the first outer tube 6a at the joining portion 9.

In this embodiment, the first outer tube 6a is
It is made of the same material, outer diameter and inner diameter as the first outer tube 6a of the first embodiment, but differs only in its axial length. The axial length L2 of the first outer tube 6a is not particularly limited, but is preferably 100 to 400 mm, and more preferably 200 to 300 mm.

The second outer tube member 6c may be made of the same material as the first outer tube member 6a, but is preferably made of another material. For example, the first outer tube member 6a is preferably made of a synthetic resin softer than the second outer tube member 6c.

The soft synthetic resin constituting the first outer tube member 6a is preferably a polyurethane, polyamide, polyimide, polyethylene or the like having a JIS hardness of 50.
About A to 90A can be used, and as the hard synthetic resin constituting the second outer tube member 6c, those having a JIS hardness of 50D to 75D such as polyurethane, polyamide, polyimide, and polyethylene can be used. .

The cross-sectional shape and size of the second outer tube 6c are the same as the cross-sectional shape and size of the first outer tube member 6a. Other configurations are the same as those of the balloon catheter 2 according to the first embodiment.
The same reference numerals are given, and the detailed description is omitted.

The balloon catheter 2B according to the present embodiment
In the first embodiment, compared to the balloon catheter 2 according to the first embodiment, except that the push-in characteristic and the insertion characteristic of the balloon catheter can be improved without mounting the reinforcing rod 28 in the catheter tube,
The same operation and effect as those of the balloon catheter 2 of the embodiment can be obtained.

Third Embodiment FIGS. 9A to 9D show a balloon catheter 2C according to another embodiment of the present invention, wherein the outer tube 6C has a relatively flexible first outer tube member 6a. And a second outer tube member 6d having relatively high rigidity that is joined to the first outer tube 6a at the joining portion 9. In the present embodiment, as shown in FIG. 9B, the second outer tube member 6d includes the reinforcing member 2 inside the tube wall of the tube member 6d.
8a is constituted by a reinforcing tube embedded therein. As the reinforcing member 28a to be embedded, for example, a metal fiber or an organic fiber is exemplified, and is uniformly embedded in the circumferential direction when the tube is formed by extrusion. After the tube member 6d is formed, the reinforcing member 28a may be attached to the outer peripheral wall or the inner peripheral wall of the tube member 6d by means such as adhesion or fusion. In the present embodiment, the joint 9
The first outer tube member 6a and the second outer tube member 6d
The outer tube 6C is integrally formed with the first outer tube 6a over the entire length without being joined, and only on the proximal end side thereof.
The reinforcing member 28a may be embedded or attached. Other configurations are the same as those of the balloon catheter 2 according to the first embodiment. Therefore, common members are denoted by common reference numerals, and detailed description thereof will be omitted.

The balloon catheter 2C according to the present embodiment
Thus, the same operation and effect as those of the balloon catheter 2B of the second embodiment can be obtained.

Fourth Embodiment FIGS. 10A to 10D show a balloon catheter 2D according to still another embodiment, in which an outer tube 6D is
It comprises a relatively flexible first outer tube member 6a and a tapered second outer tube member 6e joined to the first outer tube 6a at a joint 9. In the present embodiment, the second outer tube member 6e is formed of the same material as the first outer tube member 6a, but is formed of a tapered tube whose outer diameter gradually increases toward the proximal end. .

The inner diameter of the second outer tube member 6e may increase in proportion to the outer diameter, or may be the same along the axial direction. When the inner diameter of the second outer tube member 6e is the same along the axial direction, the thickness increases toward the proximal end, and the second moment of area increases further toward the proximal end. And the bending rigidity is improved. In addition,
Even when the inner diameter of the second outer tube member 6e increases in proportion to the outer diameter, the cross-sectional area of the second outer tube member becomes smaller toward the proximal end than when the outer diameter is uniform in the axial direction. The next moment increases, and the bending rigidity improves.

In the present embodiment, the first portion is formed at the joint 9.
Without joining the outer tube member 6a and the second outer tube member 6e, the entire length of the outer tube 6D is integrally formed of the same material as the first outer tube 6a, and only the proximal end side is formed of a tapered tube. Is also good. Or, outer tube 6D
May be constituted by an integrally molded taper tube. Other configurations are the same as those of the balloon catheter 2 according to the first embodiment. Therefore, common members are denoted by common reference numerals, and detailed description thereof will be omitted.

The balloon catheter 2D according to the present embodiment
Then, the balloon catheter 2B according to the second embodiment is described.
, Only the second outer tube 6e is a tapered tube,
Except for the function and effect resulting from the outer tube 6D having a full length or a part formed of a tapered tube, the same function and effect as those of the balloon catheter 2B of the second embodiment are exerted.

Fifth Embodiment As shown in FIG. 11, in a balloon catheter 2A according to this embodiment, a catheter tube 6A has a first outer tube member 6a having a circular cross section and the first outer tube member 6A.
a second outer tube member 6b of irregular cross-section joined to the proximal end of the inner tube 12;
2 is opened to the outside through a tube wall located in the longitudinal direction of the first outer tube member 6a.

The first outer tube 6a has the same configuration as the first outer tube 6a shown in FIG. Second outer tube member 6
b may be made of the same material as the first outer tube member 6a, but is preferably made of another material. For example, the first outer tube member 6a is preferably made of a synthetic resin that is softer than the second outer tube member 6b.

The soft synthetic resin constituting the first outer tube member 6a is preferably a polyurethane, polyamide, polyimide, polyethylene or the like having a JIS hardness of 50 or more.
About A to 90A can be used, and as the hard synthetic resin constituting the second outer tube member 6b, those having a JIS hardness of 50D to 75D such as polyurethane, polyamide, polyimide, and polyethylene can be used. .

In the present embodiment, as shown in FIG. 11C, the outer cross-sectional shape of the second outer tube member 6b has an elongated elliptical shape in the Y-axis direction. The ratio of the maximum cross-sectional width xm of the catheter tube in the X-axis direction perpendicular to the Y-axis to the maximum cross-sectional width ym in the Y-axis direction (x
m / ym) is in the range of 0.8 to 0.1, and the third lumen 24 having a semicircular cross section and the fourth lumen 2 having a circular cross section are provided.
6 are formed separately along the Y-axis direction.

The semicircular cross-sectional area of the third lumen 24 is
It is sufficient that the cross-sectional area is sufficient to allow the balloon expansion pressure fluid to flow, and is not particularly limited.
08 to 0.20 mm ² . Also, the fourth lumen 2
The circular cross-sectional area of No. ⁶ is not particularly limited as long as it is a sufficient area for inserting the reinforcing rod 28 therein, but is preferably 0.05 to 0.5 mm ² , and more preferably 0.1 to 0.5 mm ² . 0.2 mm ² .

In this embodiment, the second outer tube member 6b
, The maximum cross-sectional width ym in the Y-axis direction is 0.6
It is preferably about 1.2 mm. Second outer tube member 6b
Is joined to the proximal end of the first outer tube member 6a having a circular cross section, so that the cross-sectional shape near the joint 9 is the same as the circular cross-sectional shape with the first outer tube member 6a. In order to make them coincide with each other, the cross-sectional shape gradually changes from the deformed cross section to the circular cross section toward the joint 9.

The third lumen 24 formed along the longitudinal direction of the second outer tube member 6b communicates with the first lumen 10 of the first outer tube member 6a, and passes therethrough through the expansion space of the balloon portion 4. To take fluid in and out. The fourth lumen 26 of the second outer tube 6b is a lumen for inserting the reinforcing rod 28, and communicates with the first lumen 10 of the first outer tube member 6a. It is closed at 8 and does not allow fluid to enter or exit. The connector 8 is connected to the proximal end of the second outer tube member 6b, and has a port formed to communicate with the third lumen 24 of the second outer tube 6b. The port is a portion through which the pressurized fluid flows in and out, and does not communicate with the fourth lumen 26.

The reinforcing rod 28 shown in FIGS. 11 (B), 11 (C) and 11 (F) is inserted into the fourth lumen 26 of the second outer tube member 6b over its entire length. , Over the joint 9 with the first outer tube member 6a and protruding into the first lumen 10 of the first outer tube member 6a. The proximal end of the reinforcing rod 28 is circular in cross section, tapered from the middle toward the distal end, and further has a flat cross section at the distal end.
Its cross-sectional shape is gradually changing. As shown in FIGS. 11D and 2, the distal end of the reinforcing rod 28 having a flat cross section slightly crosses (preferably about 1 to 10 cm) the opening 22 at the proximal end of the inner tube 12. In the position
It is joined to the inner wall of the first outer tube member 6a by means such as heat fusion or adhesion.

The maximum outer diameter of the reinforcing rod 28 is the second
It is determined so that it can be inserted into the fourth lumen 26 of the outer tube member 6b, and is not particularly limited.
０．６0.6 mm.

The balloon catheter 2A according to the present embodiment
Is the same as the method for manufacturing the balloon catheter 2 according to the first embodiment shown in FIGS. 3 to 5, but differs in the following points.

That is, as shown in FIGS. 5A and 5B, a heat-sealed portion between the outer tube wall of the inner tube 12 and the inner edge of the through hole 21 which has been heat-sealed in the heat-sealing step is left. After the unnecessary portion of the inner tube 12 located outside from the heat-sealed portion is cut and removed with a cutter or the like, the process shown in FIG. As shown in FIG. 12A, the outer periphery of the second outer tube member 6b is covered with another heat sealing tube 58 having the same material and structure as the heat sealing tube 50 shown in FIG. The distal end of the second outer tube member 6b is pushed into the lumen at the proximal end of the outer tube 6a. Thereafter, as shown in FIG.
The mandrel 60 is inserted into the third lumen 24 of the outer tube member 6b along the axial direction, and its tip projects to the inside of the first outer tube member 6a. Before, after or at the same time, the fourth lumen 26 of the second outer tube member 6b
The reinforcing rod 28 is inserted along the axial direction into the inside of the first outer tube member 6a, and its distal end is positioned below the proximal end opening 22 formed on the outer periphery of the first outer tube member 6a.

Thereafter, as shown in FIG. 12C, the heat-sealing tube 58 is moved in the axial direction, and the heat-sealing tube 58 is used to connect the first outer tube member 6a and the second outer tube member 6b. The joint 9 is covered, and heat fusion is performed using a mold under the same heat sealing conditions as those described in the first embodiment.

Thereafter, the heat-sealing tube 58 is removed, the mandrel 60 is removed, and the connector 8 shown in FIG. 11 is joined to the proximal end of the second outer tube member 6b by means such as heat fusion. Then, if necessary,
An outer peripheral surface of the outer tube 6A is coated with a coating material made of a hydrophilic polymer substance having lubricity in a wet state, thereby obtaining a balloon catheter 2A shown in FIG.

The other structure and the manufacturing process of the balloon catheter 2A are the same as those of the balloon catheter 2 according to the first embodiment. Therefore, common members are denoted by common reference numerals, and detailed description thereof will be omitted.

The balloon catheter 2A according to the present embodiment
Then, in addition to the same operation and effect as the balloon catheter 2 of the first embodiment, the following operation and effect are obtained.

That is, in the present embodiment, the outer tube 6A constituting the catheter tube is constituted by the relatively soft first outer tube member 6a and the relatively rigid second outer tube member 6b. The pushing characteristics of the catheter are further improved, and the distal end side of the catheter tube is made flexible, so that the insertion characteristics in a body cavity such as a meandering blood vessel are further improved.

In this embodiment, the outer tube 6A
Is constituted by the first outer tube member 6a having a circular cross section and the second outer tube member 6b having a deformed cross section joined to the proximal end of the first outer tube member 6a. It also has an effect. That is, the cross section of the outer tube 6A on the proximal end side becomes an elliptical cross section, and this embodiment is used when two or more balloon catheters 2 are simultaneously inserted into a blood vessel such as a kissing method. In the balloon catheter 2 according to the above, even in a narrow blood vessel, the balloon catheter 2 can be inserted conveniently without imposing a load on the blood vessel.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention.

[0092]

As described above, according to the present invention, the manufacturing is easy, the outer diameter of the catheter tube is easily reduced, and the outer shape from the proximal end to the distal end of the catheter tube has a step. Thus, it is possible to provide a balloon catheter having excellent insertion characteristics of the balloon catheter and excellent push-in characteristics that are not easily kinked.

[Brief description of the drawings]

1 (A) is an overall configuration diagram of a balloon catheter according to one embodiment of the present invention, and FIG. 1 (B) is FIG. 1 (A)
FIG. 1C is a cross-sectional view taken along the line IB-IB shown in FIG.
1D is a cross-sectional view along the IC-IC line shown in FIG.
FIG. 3 is a cross-sectional view taken along a line ID-ID shown in FIG.

FIG. 2 is a longitudinal sectional view of a main part of the balloon catheter shown in FIG. 1 (A).

FIG. 3A is a perspective view of an outer tube and a balloon portion showing a manufacturing process of the balloon catheter according to the present embodiment, and FIG. 3B is a perspective view of a heat sealing tube used in the manufacturing process of the balloon catheter. FIG.

4 (A) and 4 (B) are perspective views of a main part showing a process of manufacturing a balloon catheter.

5 (A) and 5 (B) are perspective views of a main part showing a manufacturing process of a balloon catheter.

FIG. 6 is a schematic view showing a use state of the balloon catheter.

FIGS. 7A to 7C are schematic cross-sectional views showing the use state of the balloon catheter.

8 (A) is an overall configuration diagram of a balloon catheter according to another embodiment of the present invention, and FIG. 8 (B) is FIG.
FIG. 8C is a cross-sectional view taken along the line VIIIB-VIIIB shown in FIG.
8 is a sectional view taken along the line VIIIC-VIIIC shown in FIG.
FIG. 8D is a sectional view taken along line VIIID-VIIID shown in FIG.

9A is an overall configuration diagram of a balloon catheter according to another embodiment of the present invention, and FIG.
9A is a sectional view taken along the line IXB-IXB, FIG. 9C is a sectional view taken along the line IXC-IXC shown in FIG. 9A, and FIG. 9D is an IXD shown in FIG. It is sectional drawing which follows the IXD line.

10A is an overall configuration diagram of a balloon catheter according to another embodiment of the present invention, FIG. 10B is a cross-sectional view taken along line XB-XB shown in FIG. (C)
FIG. 10 is a sectional view taken along the line XC-XC shown in FIG.
FIG. 11D is a sectional view taken along line XD-XD shown in FIG.

11 (A) is an overall configuration diagram of a balloon catheter according to one embodiment of the present invention, and FIG. 11 (B) is FIG.
FIG. 11C is a cross-sectional view taken along line XIB-XIB shown in FIG.
FIG. 11 is a sectional view taken along the line XIC-XIC shown in FIG.
(D) is a sectional view taken along the line XID-XID shown in FIG.
FIG. 11E is a sectional view taken along line XIE-XIE shown in FIG. 11A, and FIG. 11F is a side view of a reinforcing rod inserted into a catheter tube of a balloon catheter.

12 (A) to 12 (C) are perspective views of a main part showing a process of manufacturing the balloon catheter shown in FIG. 11;

[Explanation of symbols]

 2, 2A, 2B, 2C, 2D Balloon catheter 4 Balloon section 6, 6A, 6B, 6C, 6D Outer tube 6a First outer tube member 6b, 6c, 6d, 6e Second outer tube member 8 Connector 10 First lumen 12 Inner tube 14 Second lumen 20 Distal end opening 21 Through hole 22 Proximal end opening 24 Third lumen 26 Fourth lumen 28 Reinforcing rod 28a Reinforcing Member 32 ... Guide catheter 34 ... Blood vessel 36 ... Stenosis 42 ... Guide wire 50, 58 ... Heat sealing tube 54, 56, 60 ... Mandrel

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shinichi Miyata 2-4-1 Shiba Park, Minato-ku, Tokyo Inside Zeon Medical Co., Ltd. (72) Inventor Takashi Kawabata 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Sun Zeon Corporation

Claims (5)

[Claims] 1. An outer tube having at least one balloon inflation lumen formed along a longitudinal direction, and a proximal end of a balloon portion joined to a distal end of the outer tube. A balloon portion that communicates with the lumen, and a distal end portion of the balloon portion is joined to a distal end portion of the inner tube so as to form a sealed expansion space inside the balloon portion; And an inner tube extending in the axial direction in the inside of the balloon expansion lumen of the outer tube, and a proximal end opening of the inner tube is located in the middle of the outer tube in the longitudinal direction. A balloon catheter, which is open to the outside through a tube wall. 2. A proximal end opening of the inner tube, wherein the proximal end opening of the inner tube is open to the outside through a tube wall positioned halfway in the longitudinal direction of the outer tube. The balloon catheter according to claim 1, wherein the outer tube and the tube wall of the outer tube are air-sealed and heat-sealed. 3. The balloon catheter according to claim 1, wherein the outer tube has a circular cross section over the entire length in the longitudinal direction. 4. The outer tube has a first outer tube member and a second outer tube member joined to a proximal end of the first outer tube member, wherein a proximal end opening of the inner tube is provided. The balloon catheter according to any one of claims 1 to 3, wherein the portion penetrates a tube wall positioned in the longitudinal direction of the first outer tube member and opens to the outside. 5. The balloon of claim 1, further comprising a distal end of an outer tube having at least one balloon inflation lumen formed longitudinally, a proximal end of the balloon portion and an interior of the balloon inflation lumen and the balloon portion. And a balloon portion proximal end portion joining step of joining so as to communicate with each other, and extending the inner tube in the axial direction inside the balloon portion and inside the balloon expansion lumen of the outer tube,
A withdrawal step of pulling out the proximal end of the inner tube to the outside of the outer tube through a through hole formed in a tube wall located in the axial direction of the outer tube; A heat fusion step of thermally fusing the outer tube wall of the inner tube located at a portion passing through a certain through hole and an inner edge of the through hole; and the inner tube thermally fused in the heat fusion step Leaving the heat-sealed portion of the outer tube wall and the inner edge of the through-hole, removing unnecessary portions of the inner tube located outside from the heat-sealed portion,
Removing the proximal end opening of the inner tube to the tube wall of the outer tube; and forming the distal end of the inner tube to form a sealed expansion space inside the balloon portion. Joining the balloon to the distal end of the balloon.