JPH02271873A - Catheter with expanding body and production thereof - Google Patents

Abstract

PURPOSE:To prevent the inside wall of a blood tube to be flawed at the time of insertion by projecting the front end of an expanding body mounted to an inside tube to the front end side from the inside tube, thereby forming the front end part of the catheter with the expanding body. CONSTITUTION:The catheter is formed of the catheter body having the inside tube 1, an outside tube 2 and the expanding body 3 and a branch hub 20. The expanding body 3 has an approximately cylindrical part 3a of nearly the same diameter partly having an approximately cylindrical shape and is foldable. The front end part 7 thereof projects to the front end side from the end of the inside tube 1 and further the front end thereof forms a round part 7a to form the front end part of the catheter. The fixing distance between the front end part 7 of the expanding body 3 and the inside tube 1 can be decreased and the fixing area can be increased by this shape, by which the peeling between both is prevented. Since the fixing end between the front end part 7 and the inside tube 1 is not exposed to the outside surface of the catheter, the peeling of the expanding body 3 at the time of the insertion of the catheter is prevented. The flawing of the inside wall of the blood tube by the front end of the catheter at the time of the progression in the blood tube is, therefore, prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a catheter with an expandable body that is used by being inserted into a body cavity, particularly a blood vessel, and a method for manufacturing the same. More specifically, the present invention relates to a catheter with an expandable body for expanding the stenosis and improving blood flow on the distal side of the stenosis in order to treat a stenosis in a blood vessel, for example, and a method for manufacturing the same.

[Prior Art] In order to treat a stenosis in a blood vessel, a catheter with an expandable body for expanding the stenosis and improving blood flow on the distal side of the stenosis is disclosed, for example, in International Publication W 08g/646.
As shown in Publication No. 5, it has an inner tube, an outer tube coaxially provided with the inner tube, a distal end and a proximal end, the proximal end is attached to the outer tube, and the distal end is attached to the outer tube. There are dilator catheters that have a collapsible dilator attached to an inner tube.

[Problems to be Solved by the Invention] The above catheter has excellent effects in terms of operability. The tip of this catheter is tapered by polishing, solvent, etc. in order to avoid damaging the inner wall of the blood vessel when advancing through the meandering blood vessel.

Generally, in a catheter with an expandable body, it is preferable that the expandable body be located closer to the distal end of the catheter. For this purpose, it is preferable that the fixed portion between the inner tube and the expansion body be short. On the other hand, in order to ensure a secure state of fixation between the expansion body and the inner tube, it is necessary to secure a fixed length of a predetermined length.

Therefore, by fixing the expansion body to the inner tube as described above and then tapering the corners, the area where the inner tube and the expansion body are fixed is reduced, albeit slightly, and the state of attachment of both is reduced. I will let you do it. For this reason, when the catheter is used, a liquid for expanding the expandable body (for example, a contrast medium) leaks from the separation part between the expandable body and the inner tube, and there is a possibility that sufficient dilation of the blood vessel cannot be achieved.

Further, in the above-mentioned catheter, the distal end of the expandable body fixed to the inner tube (the joint end of the inner tube and the expandable body) is exposed on the outer surface of the catheter. Therefore, when inserting the catheter, there is a risk that the tip of the expandable body may partially peel off and damage the inner wall of the blood vessel.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to position the expandable body sufficiently close to the distal end of the catheter, and to further reduce the length of the fixed portion between the inner tube and the expandable body. An object of the present invention is to provide a catheter with an expandable body that can be maintained and that does not cause damage to the inner wall of a blood vessel during insertion of the catheter, and a method for manufacturing the same.

[Means for solving the above problems] A device that achieves the second objective is the first one with an open end.
an inner tube having a lumen, and an outer tube provided coaxially with the inner tube and at a position set back from the tip of the inner tube by a predetermined distance, and forming a second lumen between the inner tube and the outer surface of the inner tube. tube and
a collapsible tube having a distal end and a proximal end, the proximal end attached to the outer tube, the distal end attached to the inner tube, and communicating with a second lumen near the proximal end; an expansion body, the distal end of the expansion body attached to the inner tube protrudes further toward the distal end than the inner tube, and forms the distal end of the catheter with the expansion body; It is a catheter attached to the body.

Further, it is preferable that the distal end portion of the expansion body covers the outer surface and the distal end surface of the distal end portion of the inner tube. Furthermore, it is preferable that the tip of the expansion body has a rounded shape.

In addition, the method for achieving the above purpose includes a process of forming an inner tube having a lumen that is open from the tip to the rear end, and the inner tube has a lumen that is open from the tip to the rear end, and the inner diameter is smaller than the outer diameter of the inner tube. forming an outer tube that is larger and shorter than the inner tube by a predetermined length; forming a contractible or foldable expanded body having a distal end and a proximal end; and inserting the inner tube into the outer tube. fixing the proximal end of the expandable body to the distal end of the outer tube; fixing the distal end of the expandable body to the distal end of the inner tube; A step of cutting the inner tube by a predetermined length longer than the tip thereof, and heat-processing the portion longer than the inner tube by the predetermined length, and covering the outer surface and the tip surface of the tip of the inner tube with the tip of the expansion body. This method of manufacturing a catheter with an expandable body includes a step of forming a distal end portion of the catheter.

Therefore, the catheter with an expandable body of the present invention will be explained using an embodiment shown in the drawings.

FIG. 1 is an enlarged cross-sectional view of the distal end of an embodiment of a catheter with an expandable body of the present invention, FIG. 2 is a diagram showing the proximal end of the catheter, and FIG. FIG.

The catheter with an expandable body of the present invention includes an inner tube 1 having a first lumen 4 with an open tip, and a catheter disposed coaxially with the inner tube 1 at a position set back from the tip of the inner tube 1 by a predetermined length. has an outer tube 2 which forms a second lumen 6 between it and the outer surface of the inner tube l, a distal end 7 and a proximal end 8, the proximal end 7 is attached to the outer tube 2, and the distal end 7 is attached to the inner tube 1 and includes a collapsible expandable body 3 communicating with the second lumen 6 near the proximal end, the expandable body 3 being attached to the inner tube 1. The distal end portion 7 projects further toward the distal end than the inner tube 1, and forms the distal end portion of the catheter with an expandable body.

This will be explained below using the drawings.

The catheter of the present invention is formed by a catheter body having an inner tube 1, an outer tube 2, and an expansion body 3, and a branch knob 20.

The inner tube 1 has a first lumen 4 with an open end. The first lumen 4 is a lumen for inserting a guide wire, and communicates with a first opening 9 forming a guide wire port provided in a branch hub 20, which will be described later.

The inner tube 1 preferably has a smaller diameter than either the distal end or the proximal end. Therefore, in this embodiment, the inner tube 1 is formed of a distal inner tube 1a and a proximal inner tube 1b, as shown in FIG. In this way, the outer tube 2, which will be described later, is formed by two inner tubes; the outer tube 2, which will be described later, is also formed by the distal outer tube 2a and the proximal outer tube 2b, and the distal inner tube 1a and the distal outer tube 2a. However, by making the outer diameter smaller than that of the proximal inner tube 1b and the proximal outer tube 2b, it is possible to easily insert the tube into a more distal blood vessel. The length of the small-diameter portion at the tip should be close to the length from the coronary artery entrance to the target lesion site, and particularly preferably slightly longer than the length from the coronary artery entrance to the target lesion site. stomach. Specifically, 50R11~
It is about 700H, more preferably 80R order to 400x shoulder, and particularly preferably 100 to 300 order L.

And, both the inner tube and the outer tube have their distal ends 1a.

It is preferable to provide a portion of the taper at or near the connecting portion between 2a and the proximal end sides 1b, 2b to make the change in diameter gentle.

As for the inner tube 1, the outer diameter of the distal inner tube 1a is 0.30 to 2.
．． 00xx, preferably 0.40 to 18 ozm,
The inner diameter is 0.20~1.70cm, preferably 0.25~1
．． 60+x, and the outer diameter of the proximal inner tube 1b is 0.40~
2.5Oxz, preferably 0.55-2.40x*, and the inner diameter is 0.25-2,35y,x, preferably 03
0-180m shoulder.

In addition, the inner tube 1 is not formed by the distal inner tube 1a and the proximal inner tube 1b, but the diameter of the inner tube on the distal side is made smaller than the diameter on the proximal side by, for example, extrusion molding when forming the inner tube. Alternatively, the intermediate portion may be formed with a partially tapered portion.

The material for forming the inner tube 1 is preferably one that has some degree of flexibility, such as polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, Thermoplastic resins such as polyurethane and polyamide elastomer, silicone rubber, latex rubber, etc. can be used, preferably the above-mentioned thermoplastic resins, and more preferably,
It is a polyolefin.

The outer tube 2 has the inner tube 1 inserted therein, and its distal end is provided at a position slightly retracted from the distal end of the inner tube.

As shown in FIG. 4, which is a sectional view taken along line I-1 in FIG. 1, a second lumen 6 is formed by the inner surface of the outer tube 2 and the outer surface of the inner tube 1. Therefore, the lumen can have a sufficient volume. The second lumen 6 communicates with the inside of the expandable body 3, which will be described later, at its distal end, and the rear end of the second lumen 6 communicates with the inside of the expandable body 3, which will be described later. ) is in communication with the second opening 11 of the branching hub 20 forming an injection boat for injecting the .

As shown in FIG.
a and the proximal outer tube 2b. What is formed by the two outer tubes in this way is the distal outer tube 2a.
This is because the outer diameter of the proximal outer tube 2b is smaller than that of the proximal outer tube 2b, so that it can be easily inserted into a more distal blood vessel.

Here, as the outer tube 2, the outer diameter of the distal outer tube 2a is 0.5
0-4.00 shoulder 11 preferably 086θ-3.70xx
and the inner diameter is 0.40 to 3.50x, preferably 0.
．． 50 to 270zx, and the outer diameter of the proximal outer tube 2b is 0.
75-43021, preferably l, 00-400cm, and the inner diameter is 0.70-3.80xz, preferably 0.8
0-3. OOx*.

The outer tube 2 is formed of a distal outer tube 2a and a proximal outer tube 2b, and when the outer tube is formed, for example, by extrusion molding, a part of the taper is provided. It may be formed by making the diameter smaller than the diameter of the outer tube on the proximal end side.

The material for forming the outer tube 2 is preferably one having a certain degree of flexibility, such as polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, Thermoplastic resins such as polyamide elastomer, silicone rubber, latex rubber, etc. can be used, preferably the above-mentioned thermoplastic resins, and more preferably polyolefins.

The rigidity imparting body 13 is shown in FIGS. 1, 3, 4, and 5.
As shown in the figure, it is provided within a second lumen 6 formed by the inner surface of the outer tube 2 and the outer surface of the inner tube 1. The stiffening body 13 does not reduce the flexibility of the catheter too much (prevents the catheter body from being bent excessively at the bending part, and also facilitates pushing of the tip of the catheter.

The stiffening body 13 is preferably a linear body. The linear body is preferably a metal wire, with a wire diameter of 0.05 to 1.50zx, preferably 0.10 to 1.0
Oyx stainless steel, elastic metal, superelastic alloy, etc., and particularly preferred are high tensile stainless steel for springs, copper or Ni/Ti alloy wire. Although the rigidity imparting body 13 does not necessarily have to be fixed, it is important that the tip thereof eliminates the risk of damaging the expansion body 3, and that the force applied at the proximal end of the catheter is applied to the tip of the catheter. In order to improve the transferability to the parts, it is preferable to fix the tip part of the stiffening body 13. In the embodiment shown in FIG. 1, the tip of the stiffening body 13 has a diameter smaller than that of the pond part by, for example, polishing, and the small diameter part is in contact with the tip 7 of the expansion body 3. It is located between the tubes 1 and is fixed to the distal end of the inner tube together with the expansion body 3.

As described above, by making the tip portion of the stiffening body small in diameter, it is possible to prevent a step from being formed on the outer surface of the tip portion 7 of the expansion body 3 at the fixed portion thereof. The degree of thinness is preferably about 115 to 1710 of the outer diameter of other parts in the vicinity. Furthermore, it is preferable that the rigidity imparting body 13 has higher rigidity on the base side than on the tip side. For example,
This is possible by using a rigidity imparting body that has a larger cross-sectional area on the base side than on the tip side.

Further, it is preferable that the rigidity imparting body 13 is not fixed at any portion other than the distal end and the proximal end.

When the distal end of the catheter is curved by not fixing the intermediate portion of the rigidity imparting body 13, the rigidity imparting body 13
This is preferable because it does not interfere with the flexibility of the distal end of the catheter because it is displaced into the second lumen.

The expansion body 3 is foldable, and can be folded around the outer periphery of the inner tube 1 when not expanded. The expander 3 is foldable and has a substantially cylindrical portion 3a with substantially the same diameter, at least a portion of which is substantially cylindrical so that a narrowed portion of a blood vessel can be easily expanded. The above-mentioned substantially cylindrical portion does not need to be a perfect cylinder, and may be in the shape of a polygonal column. The rear end 8 of the expandable body 3 is liquid-tightly fixed to the distal end of the outer tube 2 by adhesive or heat fusion. The distal end portion 7 is also fixed to the distal end portion of the inner tube 1 in a liquid-tight manner.

Further, as shown in FIG. 1, the distal end portion 7 protrudes further toward the distal end than the distal end of the inner tube 1, and furthermore, the protruding distal end forms a rounded portion 7a.

This rounded portion 7a forms the tip of the catheter. To explain specifically, the distal end portion 7 of the expansion body 3
The distal end covers the outer surface and the distal end surface of the distal end of the inner tube, and in particular, the portion that covers the distal end surface of the inner tube l has a rounded shape. By having such a shape,
It is possible to reduce the adhesion distance and increase the adhesion area between the distal end 7 of the expandable body 3 and the inner tube 1, thereby preventing separation between the two. Since the fixed ends between the two are not exposed to the outer surface of the Jr. Chi Chil, the fixed ends of both can be prevented from peeling off when the expansion body 3 is turned over when the catheter is inserted. Therefore, when the catheter advances within the blood vessel, the tip of the catheter will not damage the inner wall of the blood vessel.

As will be described later, this rounded portion 7a is fixed liquid-tightly to the inner tube 1. After inserting the core frame into the inner tube 1, a mold with a rounded inner surface is inserted, and this mold is heated. Therefore, it can be easily formed.

Further, the shape of the tip portion 7 is preferably rounded as described above, but it may be tapered toward the tip, or the tip may be an end surface. It's okay.

This expansion body 3 forms an expansion space 15 between the inner surface of the expansion body 3 and the outer surface of the inner tube 1, as shown in FIG. 5, which is a sectional view taken along the line ■-■ in FIG. This expansion space 15 communicates with the second lumen 6 around its entire circumference at the rear end. In this way, since the second lumen having a relatively large volume is communicated with the rear end of the expansion body 3, it is easy to inject the inflation fluid into the expansion body 3 through the second lumen. The material for forming the expansion body 3 is preferably one having a certain degree of flexibility, such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-
Polyolefins such as vinyl acetate copolymers, polyvinyl chloride, crosslinked ethylene-vinyl acetate copolymers, polyurethanes, thermoplastic resins such as polyamide elastomers, silicone rubbers, latex rubbers, etc. can be used, and the above thermoplastic resins are preferably used. More preferably, it is a crosslinked ethylene-vinyl acetate copolymer.

Further, the expansion body 3 has a tapered portion in front and rear of the cylindrical portion 3a up to the fixing portions 7 and 8 with the inner tube 1 and the outer tube 2 described above. The size of the expansion body 3 is such that the outer diameter of the cylindrical portion when expanded is 1.
00-35.0Oxyi.

Preferably it is 1.50 to 30.00xx, and the length is 3
．． 00~g0.0Oyx, preferably 10.00~75
．． OOmx and the total length of extension body 3 is 5.00
~120.0Oxx, preferably 15.00-100.
It is 0Oxx.

Also, on the outer surface of the inner tube 1, a position near the rear end side of the part where the expansion body 3 is fixed to the inner tube 1, and a position near the front end side of the part where the expansion body 3 and the outer tube 2 are fixed, Cylindrical portion 3 of extension body 3
It is made of an X-ray opaque material (for example, gold, platinum, tungsten, or an alloy thereof, or It is preferable that a marker 14 made of a silver-palladium alloy (silver-palladium alloy, etc.) is provided. Furthermore, the shape of the marker 14 is preferably made of a coil spring, as shown in FIG.
It is more preferable that it is tightly wound. This is to enable easy confirmation of the position of the expansion body 3 under X-ray fluoroscopy, and the spring-like shape prevents the inner tube located inside the expansion body from bending or collapsing at the bending part. It is preferable to form a reinforcing body.

In particular, if the marker 14 is formed of a single spring coil and this is tightly wound around the outer circumference of the inner tube 1, the resistance against external forces will be stronger. Moreover, if the cross-sectional shape of this coiled linear body is made to be an ellipse, a rectangle, or an ellipse, the resistance against external forces becomes stronger.

The branching hub 20 has a first opening 9 that communicates with the first lumen 4 to form a guide wire port, and has an inner tube hub 22 fixed to the inner tube l, and a second lumen that communicates with the injector. It consists of an outer tube hub 23 which is fixed to the outer tube 2 and has a second opening 11 forming a 9-portion. Then, the tube hub 23 and the inner tube hub 22 are fixed.

The material for forming this branch hub is polycarbonate,
Thermoplastic resins such as polyamide, polysulfone, polyarylate, and methacrylate-phthylene-styrene copolymer can be suitably used.

A sectional view of one embodiment of the branch hub 20 is shown in FIG. In this embodiment, the outer tube 2 has a bend prevention tube 50 at its distal end.

The bending prevention tube 50 is heat-shrinkable and is formed so that the inner diameter after heat-shrinking is slightly smaller than the outer diameter of the outer tube 2. It can be easily attached by fitting onto the end portion and shrinking it by heating (for example, applying hot air). The bending prevention tube 50 is fixed to the outer tube hub 23 with a stopper pin 52. This fixing method involves inserting and tightening a retaining pin 52, which has a rear end portion with an enlarged diameter and whose outer diameter at a portion other than the rear end portion is approximately equal to the inner diameter of the outer tube 2, into the rear end of the outer tube 2. is inserted into the outer tube hub 23 from its tip, and the protrusion 5 provided on the inner surface of the outer tube hub 23 is inserted into the outer tube hub 23 from its tip.
4 is pushed in until the rear end of the stop pin 52 passes. Furthermore, an adhesive may be applied to the contact surfaces of the outer tube hub 23 and the bending prevention tube 50 to fix them. Materials for forming the outer tube hub include polycarbonate, polyamide, polysulfone, polyarylate,
Thermoplastic resins such as methacrylate-butylene styrene copolymer can be suitably used.

In addition, a bending prevention tube 6 is provided at the end of the inner tube 1.
It has 0. The tube 60 is heat-shrinkable and is formed so that the inner diameter after heat-shrinking is slightly smaller than the outer diameter of the inner tube l.
It can be easily attached by fitting the tube into the end of the inner tube 1 and shrinking it by heating (for example, applying hot air). The proximal end portion of the stiffening body 13 is fixed to the outer surface of the inner tube 1 by this shrinkable tube 60.

The rigidity imparting body 13 does not necessarily have to have its base end fixed. The inner tube l to which the bending prevention tube 60 is attached is fixed to the inner tube hub 22. In this fixing method, the outer diameter of the portion other than the rear end portion of the inner tube l is attached to the rear end of the inner tube l.
Insert a retaining pin 62 having an enlarged diameter rear end portion that is approximately equal to the inner diameter of the inner tube hub 22
This is done by inserting the pin into the inner tube hub 22 and pushing in the protrusion 64 provided on the inner surface of the inner tube hub 22 until the rear end of the stop pin 62 passes over it. Furthermore, a necking agent may be applied to the contact surface between the inner pipe hub 22 and the bending prevention tube 60 to fix them. As the material for forming the inner tube huff, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene co-ffl combination can be suitably used. As shown in FIG. 6, the inner pipe hub 22 and the outer pipe hub 23 are fixed. This fixation is performed by inserting and joining the inner tube 1 from the rear end of the outer tube hub 23 attached to the proximal end of the outer tube 2 from its tip. Further, at this time, by applying an adhesive to the joint between the inner pipe hub 22 and the outer pipe hub 23, it is possible to reliably fix the two.

Alternatively, the branch hub may not be provided, and a tube having a boat member having an opening at its rear end may be fluid-tightly attached to each of the first lumen and the second lumen.

Next, a method of manufacturing a catheter with an expandable body according to the present invention will be explained using an embodiment shown in the drawings.

FIG. 1 is an enlarged sectional view of one embodiment of a catheter with an expandable body manufactured according to the present invention.

The catheter with an expandable body is provided coaxially with an inner tube 1 having a first lumen 4 having an open tip and an inner tube l,
An outer tube 2 is provided at a position set back a predetermined distance from the distal end of the inner tube 1 and has a second lumen 6 between it and the outer surface of the inner tube 1, a distal end portion 7 and a proximal end portion 8. The end portion 8 is attached to the outer tube 2, and the distal end portion 7 is attached to protrude distally from the inner tube 1, forming the tip of the catheter, and communicating with the second lumen 6 near the proximal end.It is foldable. a first opening 9 provided at the proximal end of the inner tube l communicating with the first lumen 4; and a first opening 9 provided at the proximal end of the outer tube 2 communicating with the second lumen 6. a second opening 11 provided;
It has a rigidity imparting body 13 provided in the second lumen 6 that extends in the axial direction and imparts rigidity.

This will be explained below using the drawings.

Next, a method for manufacturing a catheter with an expandable body according to the present invention will be explained using the drawings.

The manufacturing method of the present invention includes a step of molding an inner tube having a lumen that is open from the tip to the rear end, and a lumen that is open from the tip to the rear end and has an inner diameter larger than the outer diameter of the inner tube. forming an outer tube that is shorter than the inner tube by a predetermined length; forming a contractible or foldable expandable body having a distal end and a proximal end; inserting the inner tube into the outer tube; and inserting the inner tube into the outer tube. fixing the proximal end of the expandable body to the distal end of the tube, fixing the distal end of the expandable body to the distal end of the inner tube, and heating the fixed distal end of the expandable body, forming the tip of the catheter.

Therefore, each step will be explained with reference to the expandable catheter shown in FIG.

The process of forming the inner tube 1 having the first lumen 4 communicating from the tip to the rear end is carried out by extrusion molding the thermoplastic resin constituting the inner tube and cutting it into a predetermined length, or by injection molding. Formed by law etc.

The process of forming the outer tube 2 includes a process of forming a distal outer tube 2a having a lumen penetrating from the distal end to the rear end, and a distal outer tube 2a having an outer diameter larger than the outer diameter of the distal outer tube 2a and a distal end A process of forming the proximal outer tube 2b having a lumen penetrating from the base to the rear end, forming one end of the proximal outer tube 2b into a tapered shape, and expanding the diameter of one end of the distal outer tube 2a. Process and tapered proximal outer tube outer tube 2b
and a step of fixing the tapered end of the outer tube 2a and the enlarged diameter end of the distal outer tube 2a whose diameter has been enlarged.

Next, a process for forming a contractible or foldable expandable body having a distal end and a proximal end will be described.

The expansion body 3 is preferably flexible, for example,
Polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer, etc., thermoplastic resins such as polyvinyl chloride, polyurethane, more preferably cross-linked ethylene - Can be formed using a vinyl acetate copolymer. For example, a tube made of thermoplastic resin for forming the expansion body 3 is formed, a tube holder is attached to the distal end of the tube, and the lumen of the tube is closed near the tube holder. Then, the occluded tube is pulled in the opposite direction by applying a load to the tube holder to remove the slack in the tube, and a heating device is used to heat the part that will form the expanded body to the melting point of the material forming the tube. Heat to around 100 ml. The tube is maintained in a heated state, the lumen is expanded with a mold formed in the tube, and gas is fed into the tube while being pressurized. Make sure that the part of the tube that is attached is in close contact with the inner wall of the mold. Then, the tube is left under pressure until it returns to room temperature, and then the inside of the tube is made negative pressure, the part that will become the expansion body is contracted, and the mold is removed. Then, by cutting the tube at the tip and rear ends of the tube, an expanded body can be formed.

Further, at least the distal end and the proximal end of the expansion body are
If it has heat shrinkability, the expansion body 3 can be easily attached to the outer tube 2 and the inner tube 1 by using its heat shrinkability. Methods for imparting heat shrinkability to at least the distal and proximal ends of the expandable body include a method of forming the expandable body from a cross-linked thermoplastic resin, a method using a cross-linked resin, and the above-mentioned methods of forming the expandable body. In the forming step, if the expansion body is formed by heating at a temperature at which strain remains in the expansion body, the expansion body can be made to have heat shrinkability.

Furthermore, after forming the inner diameter of the distal end of the expandable body to be slightly smaller than the outer diameter of the inner tube and the proximal end to be slightly smaller than the outer diameter of the outer tube, both ends of the expandable body are expanded in diameter (by stretching). It can be made to have heat shrinkability.

This process of forming the expanded body may be performed at any time (and may be performed in any order with the process of forming the inner tube and outer tube described above).

Next, a process of providing an opening 11 communicating with the lumen 6 of the outer tube at the proximal end of the outer tube 2 will be explained. The opening 11 is preferably formed by attaching an outer tube hub 23 having an opening to the proximal end of the outer tube 2. Taking this case as an example, it will be explained using FIG.

First, a bending prevention tube 50 is attached to the end of the outer tube 2.
Attach. This installation method uses a heat-shrinkable tube 50 for preventing bending, and the heat-shrinkable tube 50 is formed so that the inner diameter after heat shrinking is slightly smaller than the outer diameter of the outer tube 2. It can be attached by fitting it onto the end of the outer tube 2 and shrinking it by heating (for example, applying hot air). Then, the outer tube hub 23 is attached to the outer tube 2 to which the bending prevention tube 50 is attached. This installation method involves inserting a retaining pin 52 into the rear end of the outer tube 2, the outer diameter of which is approximately equal to the inner diameter of the outer tube 2 other than the rear end portion, and which has an enlarged diameter rear end portion. 2 into the outer tube hub 23 from its tip,
The protrusion 54 provided on the inner surface of the outer tube hub 23 is fixed to the pin 5.
Attach by pushing in until the rear end of 2 goes over. Furthermore, an adhesive may be applied to the contact surface between the outer tube hub 23 and the bending prevention tube 50 to fix them. As the material for forming the outer tube hub, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.

The step of providing the opening 11 communicating with the lumen 6 of the outer tube 2 at the proximal end of the outer tube 2 may be performed at any time after the outer tube 2 is formed. Preferably, this is carried out after performing a step of fixing the proximal end of the expansion body 3 to the distal end of the outer tube 2, which will be described later. Note that the process for forming the inner tube 1 may be performed in any order.

Next, a process of providing an opening 9 communicating with the lumen 4 of the inner tube 1 at the proximal end of the inner tube 1 will be explained. The opening 9 is
Inner tube knob 2 having a first opening 9 at the proximal end of the outer tube 1
It is preferable to do this by attaching 2. Taking this case as an example, it will be explained using FIG.

First, a bending prevention tube 60 is attached to the end of the inner tube 1.
Attach. This attachment method uses a heat-shrinkable tube 60, which is formed so that the inner diameter after heat-shrinking is slightly smaller than the outer diameter of the inner tube 1, at the end of the inner tube 1. This can be easily done by fitting the material onto the material and shrinking it by heating (for example, applying hot air). Furthermore, in the embodiment shown in FIG. 6, a rigidity imparting body 13 is provided between the inner tube 1 and the outer tube 2, and the ends of this rigidity imparting body 13 are connected to the prevention tube 60 and the inner tube 2. By performing the heat treatment described above after positioning the tube 60 between the inner tube 2 and the inner tube 2, the tube 60 can be attached to the inner tube 2 and fixed at the same time, as shown in FIG.

Then, the bending prevention tube 60 and the rigidity imparting body 1
Attach the inner tube hub 22 to the inner tube 1 to which the inner tube 3 is attached. This installation method involves inserting a retaining pin 62 into the rear end of the inner tube l, the outer diameter of which is approximately equal to the inner diameter of the inner tube 1 other than the rear end portion, and which has an enlarged rear end portion. is inserted into the inner tube hub 22 from its tip, and attached by pushing the protrusion 64 provided on the inner surface of the inner tube hub 22 until the rear end portion of the stopper pin 62 passes over it. Furthermore, an adhesive may be applied to the contact surface between the inner pipe hub 22 and the bending prevention tube 60 to fix them. The material for forming the inner tube hub is
Something similar to the outer tube hub can be suitably used.

The step of providing the opening 9 communicating with the lumen 4 of the inner tube at the proximal end of the inner tube may be performed at any time after the inner tube 1 is formed. What is the order of the step of forming the outer tube 2, the step of providing the second opening 11 communicating with the lumen 6 of the outer tube at the proximal end of the outer tube 2, and the step of forming the expansion body 3? Good too.

Next, the process of fixing the proximal end portion 8 of the expansion body 3 to the distal end portion of the outer tube 2 will be explained.

A method for fixing the proximal end 8 of the expandable body 3 to the distal end of the outer tube 2 is to use a cored metal having an outer diameter that is approximately equal to or slightly smaller than the inner diameter of the outer tube 2 than the distal or rear end of the outer tube 2. The expansion body 3 is inserted from the distal side of the core bar so that the distal end of the proximal end 8 of the expandable body 3 is aligned with the distal end of the outer tube 2. Then, a glass mold for bonding is fitted over the base end 8 of the expansion body 3, and this glass mold is heated by a heating device, and the expansion body 3 is heated.
The proximal end 8 of is fixed to the distal end of the outer tube 2. Furthermore, if the proximal end portion 8 of the expandable body 3 is formed to have heat-shrinkability, it can be easily fixed because it is thermally shrunk by heating with the glass mold. Proximal end 8 of expansion body 3
After fixing the glass mold to the distal end of the outer tube 2, the glass mold is left to reach room temperature, the glass mold is moved back from the joint, and the core bar is removed. The tip of No. 3 can be easily fixed.

Furthermore, although a glass mold is used in the above description, the present invention is not limited to this, and for example, a bonding mold may be used.

Alternatively, an electrode for high frequency transmission may be fitted onto the proximal end 8 of the expansion body 3 using a metal core, and the electrodes may be fixed by being fused by high frequency induction heating, or by using ultrasonic waves. It may also be fused.

Note that the step of fixing the proximal end portion 8 of the expansion body 3 to the distal end portion of the outer tube 2 may be performed at any time after the formation of the outer tube 1 and the expansion body 3. The order of the steps of forming the inner tube 1 and providing the opening 9 communicating with the lumen 4 of the inner tube at the proximal end of the inner tube 1 may be arbitrary.

Next, a process of fixing the inner tube hub 22 having an opening attached to the proximal end of the inner tube 1 and the outer tube hub 23 attached to the proximal end of the outer tube 1 will be described.

As shown in FIG. 6, the inner tube 1 is inserted from the rear end of the outer tube hub 23 attached to the proximal end of the outer tube 2 from its tip. At this time, in order to prevent the inner tube 1 from bending, a core metal is inserted into the inner tube l, and the tip of the inner tube hub 22 is inserted into the rear end of the outer tube hub 23, as shown in FIG. and join.

Further, at this time, by applying an adhesive to the joint between the inner tube hub 22 and the outer tube hub 23, it is possible to reliably fix them together.

Note that the process of fixing the inner tube hub 22 having an opening attached to the proximal end of the inner tube l and the outer tube hub 23 attached to the proximal end of the outer tube 1 forms the inner tube 1. A step and a step of providing an inner tube hub 22 at the proximal end of the inner tube I, and a step of forming an outer tube I and an outer tube hub 23 at the proximal end of the outer tube 2.
It is only necessary to perform the step of providing the above. Preferably, this is carried out after forming the expansion body 3 and fixing the expansion body 3 and the outer tube 1.

Next, a process of fixing the distal end 7 of the expansion body 3 to the distal end of the inner tube 1 and a process of heating the distal end of the fixed expansion body will be described.

As shown in FIG. 8, the method of fixing the distal end of the expandable body 3 to the distal end of the inner tube 1 includes fixing the expandable body 3 and the outer tube 2 and attaching the distal end of the expandable body 3 to the proximal end of the inner tube 1. An example will be described in which the process is performed after the inner tube hub 22 and the outer tube hub 23 attached to the proximal end of the outer tube 2 are fixed.

As shown in FIG. 7, a core frame 80 having an outer diameter approximately equal to or slightly smaller than the inner diameter of the inner tube 1 is protruded from the tip or rear end of the inner tube 1 by 10 to 15 zx. insert. Further, as shown in FIG. 8, the expansion body 3 is fixed to the distal end of the outer tube 2, and an outer tube hub 23 is attached to the proximal end of the outer tube 2, and the inner tube into which the core frame 80 is inserted is attached. The inner tube hub 22 inserted from the distal end of the inner tube 1 and attached to the proximal end of the inner tube 1 is fixed to the outer tube hub 23.
protrudes from the distal end of the outer tube 2 and further from the distal end of the expandable body 3, and is located within the distal end extension portion 77 of the expandable body 3. Next, as shown in FIG. 9, a glass mold 82 for bonding is positioned on the distal end side of the distal end extension portion 77 of the expandable body 3, and further on the distal end portion 7 of the expandable body 3 from the distal end side of the core frame 80. This glass mold 82 is heated by a heating device (not shown), and the distal end 7 of the expansion body 3 is fixed to the distal end of the inner tube l. Preferably, if the distal end portion 7 of the expandable body 3 is formed to have heat shrinkability,
By heating with the glass mold 82, the glass mold 82 naturally shrinks and can be easily fixed. In this way,
After fixing the distal end 7 of the expandable body 3 to the distal end of the inner tube 1, the glass mold 82 is left until it reaches room temperature, and the glass mold 82 is retreated from the joint and removed.
and the distal end of the inner tube 1 can be fixed together.

In addition, although a glass mold was used in the above explanation, it is not limited to this.
For example, a joining mold may be used, or a metal core frame 80 may be used, an electrode for high frequency transmission may be fitted onto the tip 7 of the expansion body 3, and the electrodes may be fixed by being fused by high frequency. Alternatively, ultrasonic waves may be used for fusing.

Then, the fixed expansion body is cut to a predetermined length longer than the tip of the catheter. This process, as shown in Figure 10,
The distal end extension portion 77 of the expansion body 3 is l+y from the distal end of the inner tube 1.
Cut at arrow A-A about x on the tip side. Clean cutting can be achieved by cutting along the circumferential direction of the core frame 80 using a cutting tool such as a razor.

Then, a portion longer than the catheter by a predetermined length is thermally processed. As mentioned above, the catheter whose distal end portion has been cut to a predetermined length is heated to a heat treatment type 96 as shown in FIG.
and push it in until it stops. The heat treatment mold 96 has a cylindrical recess 97 having an inner diameter approximately equal to the outer diameter of the joint between the distal end 7 of the expandable body 3 and the inner tube l, and a core frame is provided at the bottom of the center of the recess 97. Hole 9 through which 80 can be inserted
8 is provided. Further, the bottom portion of the cylindrical recess 97 has a portion longer than the catheter by a predetermined length that is heat-treated to have a desired shape (for example, a shape in which the corners are rounded to avoid rounding); The tip of the catheter after heat treatment is rounded. Then, by heating the heat treatment mold 96 and further pushing it lightly in the direction of the tip, the tip extension portion 77 corresponding to the predetermined long portion becomes molten, and the molten portion deforms to match the shape of the bottom of the recess 97. , and flows into the space formed between the distal end of the inner tube 1 and the distal end extension portion 77 to form a rounded portion 7a at the distal end portion of the catheter. Then, as shown in FIG. 12, the heat treatment mold 96 into which the distal end of the catheter is inserted is cooled. As for the cooling method,
The heated heat treatment mold 96 is placed in a cooling container 99 containing a refrigerant such as cold water, and the heat treatment mold 96 is heated.
This is done by leaving it as is until it is sufficiently cooled. After the heat treatment mold 96 has been sufficiently cooled, it is taken out from the cooling container 99 and the heat treatment mold 96 is removed.
By pulling out the core frame 80 from the inner tube 1, a catheter with an expandable body having a rounded portion 7a formed at the distal end as shown in FIG. 13 is manufactured.

[Function] Next, the function of the catheter with an expandable body of the present invention will be explained using the catheter with an expandable body of the embodiment shown in FIGS. 1 through 6 and with reference to FIGS. 14 to 18. do.

It is preferable to remove as much air as possible from the catheter with an expandable body before performing dilation treatment for a stenosis created in a blood vessel. Therefore, the second opening 1 of the catheter of the present invention
Attach a suction and injection means such as a syringe to 1, fill the syringe with a liquid (such as a vascular contrast agent), and repeat suction and injection to remove the air in the second lumen and the expansion body and replace it with liquid. .

To insert the expandable catheter, first secure the blood vessel using the Seldingo method or the like, place a guide wire for the guide catheter (not shown) in the blood vessel, and insert the guide catheter 30 into the blood vessel along the guide wire. 15th
As shown in the figure, a guide catheter 30 is placed in a coronary artery population 32 having a target lesion, and the guide wire for the guide catheter is removed. As shown in FIG. 14, the expandable body catheter 40 of the present invention, through which the expandable body catheter guide wire 34 is inserted, is inserted through the Y-shaped connector 50 provided at the rear end of the guide catheter 30, and the expandable body catheter 40 is inserted through the expandable body catheter guide wire 34. The catheter 40 is inserted into the blood vessel in a state in which the guide wire 34 for the catheter with an expandable body protrudes several ax from the distal end thereof.

The expandable catheter 40 advances within the guide catheter 30 and enters the blood vessel 35 having the target lesion from the distal end of the guide catheter 30, as shown in FIG. The tube is advanced to the stenosis section, passed through the stenosis section 36, and left in place. The expandable catheter 40 advances within the blood vessel 35 along the expandable catheter guide wire 34 . The catheter 40 with an expandable body that has reached the constriction 36 inserts the expandable body 3 into the constriction 36 under X-ray fluoroscopy using the X-ray opaque marker 14 provided on the inner tube 1 as a guide, as shown in FIG. 17J. position. Thereafter, the angiographic agent is injected with the injector 54 equipped with a pressure gauge connected to the second opening forming the injection boat of the catheter with expandable body 40 to a pressure of several atm to about 10-odd atm, as shown in FIG. The narrowed portion 36 is compressed and enlarged.

Then, the peripheral blood flow is confirmed by injecting a contrast medium from the contrast medium injection port 52 of the figure 7 connector 50 of the guide catheter 30 and using X-ray contrast. If the blood flow is improved, the expandable catheter 40 and the expandable catheter guide wire 34 are removed, and then the guide catheter is removed and the procedure is stopped by applying pressure.

[Effects of the Invention] The catheter with an expandable body of the present invention includes an inner tube having a first lumen with an open tip, and an inner tube provided coaxially with the inner tube and recessed by a predetermined length from the tip of the inner tube. set in position,
an outer tube forming a second lumen between the outer tube and the outer surface of the inner tube; and a distal end and a proximal end, the proximal end being attached to the outer tube, and the distal end attached to the inner tube. a collapsible expandable catheter attached to the inner tube and communicating with a second lumen near the proximal end, the distal end of the expandable body attached to the inner tube being in communication with the second lumen near the proximal end; Since it protrudes toward the distal end side of the tube and forms the distal end of the catheter, it is possible to reduce the adhesion distance and increase the adhesion area between the distal end of the expansion body and the inner tube, and to increase the adhesion area between the two. Furthermore, since the fixed end between the distal end of the expandable body and the inner tube is not exposed to the outer surface of the catheter, the expandable body can be peeled off at both fixed ends when the catheter is inserted. can be prevented. Therefore, when the catheter advances within the blood vessel, the tip of the catheter does not damage the inner wall of the blood vessel.

Further, the method for manufacturing a catheter with an expandable body of the present invention includes a step of molding an inner tube having a lumen that is open from the tip to the rear end, and a step of forming an inner tube that has the lumen that is open from the tip to the rear end. a step of forming an outer tube having a larger inner diameter and a predetermined length shorter than the inner tube; and a step of forming a contractible or foldable expandable body having a distal end and a proximal end;
a step of inserting the inner tube into the outer tube; a step of fixing the proximal end of the expansion body to the distal end of the outer tube; and a step of fixing one end of the fixed expansion body to a predetermined length beyond the tip of the inner tube. a step of cutting the inner tube into a long length; and a step of thermally processing the portion longer than the inner tube by a predetermined length to cover the outer surface and the distal end surface of the distal end of the inner tube with the distal end portion of the expansion body to form the distal end portion of the catheter. The above-mentioned catheter with an expandable body can be reliably used, and the distal end of the expandable body and the distal end of the catheter are integrated, without using a separate member.
It can be easily manufactured.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of the distal end of an embodiment of the catheter with an expandable body of the present invention, FIG. 2 is a drawing showing the proximal end of an embodiment of the catheter with an expandable body of the present invention, and FIG. The figure is a cross-sectional view of the intermediate part of one embodiment of the catheter with an expandable body of the present invention, FIG. 4 is a cross-sectional view taken along the line r-I in FIG. 1, and FIG. 5 is a cross-sectional view taken along the line A cross-sectional view, FIG. 6 is a cross-sectional view of the proximal end of an embodiment of the catheter with an expandable body of the present invention, and FIGS. 7 to 13 are for explaining the manufacturing method of the catheter with an expandable body of the present invention. 14 to 18 are diagrams showing the operation of the catheter with an expandable body of the present invention. l...Inner tube 3...Expansion body 6...Second lumen 11...Second opening 14...Marker 20...Branch hub 23...Outer tube hub 80... - Core frame 2...Outer tube 4...First lumen 9...First opening 13...Rigidity imparting body 22...Inner tube hub 77...Tip extension portion 96...・Heat treatment type Fig. 1 Fig. 2 Fig. 8 Fig. 15 Fig. 14

Claims (4)

[Claims] (1) An inner tube having a first lumen with an open tip, provided coaxially with the inner tube, provided at a position set back from the tip of the inner tube by a predetermined length, and connected to the outer surface of the inner tube. between the second
an outer tube forming a lumen, a distal end portion and a proximal end portion, the proximal end portion being attached to the outer tube, the distal end portion being attached to the inner tube, and a second tube near the proximal end portion; A catheter with an expandable body having a foldable expandable body that communicates with a lumen No. 2, wherein a distal end portion of the expandable body attached to the inner tube projects toward the distal end side of the inner tube, and the expandable body is attached to the inner tube. A catheter with an expandable body, characterized in that the distal end portion of the catheter with an expandable body is formed. (2) The catheter with an expandable body according to claim 1, wherein the distal end portion of the expandable body covers the outer surface and the distal end surface of the distal end portion of the inner tube. (3) Claim 1, wherein the distal end of the expansion body has a rounded shape.
or the catheter with an expandable body according to 2. (4) a process of forming an inner tube having a lumen open from the tip to the rear end, having an inner diameter larger than the outer diameter of the inner tube, and having a predetermined diameter than the inner tube; a step of forming a long and short outer tube; a step of forming a contractible or foldable expandable body having a distal end and a proximal end; a step of inserting the inner tube into the outer tube; and a distal end of the outer tube. fixing the proximal end of the expansion body to the inner tube; cutting one end of the fixed expansion body a predetermined length longer than the distal end of the inner tube; and thermally processing the portion longer than the inner tube by the predetermined length. A method for manufacturing a catheter with an expandable body, comprising the step of: covering the outer surface and the distal end surface of the distal end of the inner tube with the distal end of the expandable body to form a distal end of the catheter.