JPH0798064B2 - Catheter with expandable body and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a catheter with an expandable body which is used by inserting it into a body cavity, particularly a blood vessel, and a method for producing the same. More specifically, the present invention relates to a dilatation catheter for expanding a stenosis and improving blood flow on the peripheral side of the stenosis, for example, for treating a stenosis in a blood vessel, and a manufacturing method thereof.

[Prior Art] A catheter with an expandable body for expanding a stenosis and improving blood flow on the peripheral side of the stenosis in order to treat the stenosis in the blood vessel is disclosed in, for example, International Publication WO88 / 6465. As shown in Fig. 2, the inner pipe, the outer pipe coaxially provided with the inner pipe, the tip portion and the base end portion, the base end portion is attached to the outer pipe, the tip portion to the inner pipe There are catheters with expanders that have a foldable expander attached.

[Problems to be Solved by the Invention] The catheter described above has an excellent effect in terms of operability. The tip of this catheter is tapered in a tapered shape by a method such as polishing or solvent so as not to damage the inner wall of the blood vessel when advancing a meandering blood vessel.

In general, it is preferable that the dilator in the catheter with the dilator be located on the distal side of the catheter. For that purpose, it is preferable that the fixed portion between the inner tube and the expansion body is short. On the other hand, it is necessary to secure a fixed portion of a predetermined length in order to secure a reliable fixed state of the expansion body and the inner tube. Therefore, if the expansion body is fixed to the inner tube as described above and then the corner is tapered, the adhesion portion between the inner tube and the expansion body is reduced, but the fixation state of both is reduced. I will let you. For this reason, when the catheter is used, the dilating liquid (for example, the contrast agent) is used to dilate the dilator into the dilator.
There is a possibility that leakage may occur from the separation portion between the expansion body and the inner tube, and sufficient expansion of the blood vessel may not be realized.

Further, in the above catheter, the tip of the expansion body fixed to the inner tube (the joint end between the inner tube and the expansion body) is exposed on the outer surface of the catheter. Therefore, at the time of inserting the catheter, there is a risk that the distal end of the expandable body is partially peeled off to damage the inner wall of the blood vessel.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to allow the position of the dilating body to be sufficiently on the distal side of the catheter, and further to lengthen the fixed portion between the inner tube and the dilating body. (EN) It is possible to provide a catheter with an expandable body that can be maintained and does not damage the inner wall of a blood vessel when inserting the catheter, and a method for manufacturing the catheter.

[Means for Solving the Problems] The object to achieve the above object is to provide an inner tube having a first lumen with an open distal end, and to provide the inner tube coaxially with the inner tube.
An outer tube provided at a position retracted by a predetermined length from the tip of the inner tube and forming a second lumen between the inner tube and the outer surface of the inner tube, and a tip section and a base section. A catheter having a foldable expander attached to the outer tube, the distal end portion being attached to the inner tube, and the second lumen being in communication with the second lumen near the proximal end portion. The distal end portion of the attached expansion body is a catheter with an expansion body that protrudes further toward the tip side than the inner tube to form the tip portion of the catheter with an expansion body.

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

Further, what achieves the above-mentioned object is a step of molding an inner pipe having a lumen opened from the front end to the rear end, and a lumen opened from the front end to the rear end, the inner diameter of which is larger than the outer diameter of the inner pipe. And a step of forming an outer tube that is shorter than the inner tube by a predetermined length, a step of forming a contractable or foldable expansion body having a distal end portion and a proximal end portion, and a step of inserting the inner tube into the outer tube. A step of fixing a base end portion of the expansion body to a distal end portion of the outer tube, a step of fixing a tip end portion of the expansion body to a distal end portion of the inner tube, and a step of fixing one end of the fixed expansion body to the inner pipe A step of cutting for a predetermined length longer than the tip of
With an expandable body, which comprises the step of heat-processing the portion that is longer than the inner tube by a predetermined length, and coating the outer surface and the distal end surface of the inner tube with the distal end of the expandable body to form the distal end of the catheter. It is a manufacturing method of a catheter.

Therefore, the catheter with an expandable body of the present invention will be described with reference to an embodiment shown in the drawings.

FIG. 1 is an enlarged cross-sectional view of a distal end portion of an embodiment of a catheter with an expandable body of the present invention, FIG. 2 is a drawing showing a proximal end portion of the catheter, and FIG. 3 is an intermediate portion of the catheter. It is a sectional view of a part.

INDUSTRIAL APPLICABILITY The catheter with an expandable body of the present invention is provided coaxially with an inner tube 1 having a first lumen 4 whose tip is open, and is provided at a position retracted from the tip of the inner tube 1 by a predetermined length. And an outer tube 2 forming a second lumen 6 between the outer tube 2 and the outer surface of the inner tube 1, and a distal end portion 7 and a proximal end portion 8. The proximal end portion 7 is attached to the outer tube 2, and the distal end portion is attached. 7 is a catheter having a foldable expansion body 3 attached to the inner tube 1 and communicating with the second lumen 6 in the vicinity of the proximal end of the expansion body 3 attached to the inner tube 1. The distal end portion 7 projects toward the distal end side with respect to the inner tube, and forms the distal end portion of the catheter with an expandable body.

Hereinafter, description will be given with reference to the drawings.

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

The inner tube 1 has a first lumen 4 having an open tip. The first lumen 4 is a lumen for inserting a guide wire, and communicates with a first opening 9 which forms a guide wire port provided in a branch hub 20 described later. The inner tube 1 preferably has a tip end portion having a smaller diameter than the base end portion. Therefore, in this embodiment, as shown in FIG. 3, the inner pipe 1 is formed by the distal end inner pipe 1a and the proximal end inner pipe 1b. In this way, the two inner pipes are formed so that the outer pipe 2 described later is also formed by the distal end outer pipe 2a and the proximal end outer pipe 2b, and the distal end inner pipes 1a and 2a are This is because by making the outer diameter smaller than that of the lateral inner tube 1b and the proximal outer tube 2b, it is possible to easily insert a blood vessel on the more distal side. And, the length of the portion where the tip portion has a small diameter is preferably a length close to the length from the coronary artery entrance to the target lesion site, particularly preferably slightly longer than the length from the coronary artery entrance to the target lesion site. Yes. Specifically, it is about 50 mm to 700 mm, more preferably 80 mm to 400 mm, and particularly preferably 100 to 300 mm.
Is.

It is preferable that both the inner pipe and the outer pipe are provided with a taper portion at or near the connection portion between the tip end side 1a, 2a and the base end side 1b, 2b to make the diameter change gentle.

As the inner pipe 1, the outer diameter of the tip-side inner pipe 1a is 0.30 to 2.00 mm,
It is preferably 0.40 to 1.80 mm, the inner diameter is 0.20 to 1.70 mm,
It is preferably 0.25 to 1.60 mm, and the outer diameter of the proximal end side inner tube 1b is
0.40 ~ 2.50 mm, preferably 0.55 ~ 2.40 mm, with an inner diameter
It is 0.25 to 2.35 mm, preferably 0.30 to 1.80 mm.

Further, the inner pipe 1 is not formed by the inner pipe 1a on the distal end side and the inner pipe 1b on the proximal end side, and the inner pipe on the distal end side is made smaller than the diameter on the proximal end side by, for example, extrusion molding when molding the inner pipe. Alternatively, it may be formed by providing a taper portion in the intermediate portion.

As a material for forming the inner tube 1, a material having a certain degree of flexibility is preferable, and examples thereof include polyolefin 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 and the like can be used, preferably the above-mentioned thermoplastic resins, and more preferably polyolefin.

The outer tube 2 is provided at a position where the inner tube 1 is inserted into the outer tube 2 and the tip is slightly retracted from the tip of the inner tube. As shown in FIG. 4 which is a sectional view taken along the line I-I in FIG.
A second lumen 6 is formed by the inner surface of the inner tube 1 and the outer surface of the inner tube 1. Therefore, a lumen having a sufficient volume can be obtained. Then, the second lumen 6 communicates with the inside of the expansion body 3 described later at the tip thereof and at the rear end thereof, and the rear end of the second lumen 6 has a fluid for expanding the expansion body (for example, a blood vessel contrast agent). ) Is in communication with the second opening 11 of the branch hub 20 forming an injection port.

The outer tube 2 is, as shown in FIG.
And the proximal outer tube 2b. The two outer tubes are thus formed, because the outer tube 2a on the distal end side has a smaller outer diameter than the outer tube 2b on the proximal end side, so that even a blood vessel on the more distal side can be easily inserted. is there.

Here, as the outer tube 2, the outer diameter of the tip-side outer tube 2a is 0.50 to 4.
00 mm, preferably 0.60-3.70 mm, with an inner diameter of 0.40-3.
50 mm, preferably 0.50 to 2.70 mm, the outer diameter of the proximal end outer tube 2b is 0.75 to 4.30 mm, preferably 1.00 to 4.00 mm,
The inner diameter is 0.70 to 3.80 mm, preferably 0.80 to 3.00 mm.
Further, the outer tube 2 is formed of the outer tube 2a on the distal end side and the outer tube 2b on the proximal end side. May be made smaller than the diameter of the outer tube on the base end side. As a material for forming the outer tube 2, a material having a certain degree of flexibility is preferable, and examples thereof include polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, A thermoplastic resin such as a polyamide elastomer, silicon rubber, latex rubber or the like can be used, preferably the above-mentioned thermoplastic resin, more preferably polyolefin.

The rigidity imparting body 13 is provided inside the second lumen 6 formed by the inner surface of the outer tube 2 and the outer surface of the inner tube 1, as shown in FIGS. 1, 3, 4, and 5. Has been. The rigidity imparting body 13 prevents the catheter body from being excessively bent at the bent portion and facilitates the pushing of the catheter tip end without significantly reducing the flexibility of the catheter.

The rigidity imparting body 13 is preferably a linear body.
The linear body is preferably a metal wire and has a wire diameter of 0.
05-1.50 mm, preferably 0.10-1.00 mm stainless steel,
Elastic metals, superelastic alloys, etc. are particularly preferable, and high-strength stainless steel for springs, copper or Ni / Ti alloy wire is preferable. The rigidity imparting body 13 does not necessarily have to be fixed, but the tip portion thereof eliminates the risk of damaging the dilation body 3, and the catheter tip of the force given at the proximal end portion of the catheter. In order to improve the transmissibility to the portion, it is preferable to fix the tip of the rigidity imparting body 13. In the embodiment shown in FIG. 1, the tip end portion of the rigidity imparting body 13 has a smaller diameter than the other portion by, for example, a method such as polishing, and the thin diameter portion is located inside the tip end portion 7 of the expansion body 3. It is located between the pipes 1 and is fixed to the distal end of the inner pipe together with the expansion body 3. As described above, by making the tip end portion of the rigidity imparting body thin, it is possible to prevent a step from being formed on the outer surface of the tip end portion 7 of the expansion body 3 at the fixing portion. The degree of the small diameter is preferably about 1/5 to 1/10 of the outer diameter of other portions in the vicinity thereof. Furthermore, the rigidity imparting body 13 preferably has a higher rigidity on the base side than on the tip side. This can be achieved, for example, by using a rigidity imparting body having a larger cross-sectional area at the base end portion than at the tip end portion.

Furthermore, it is preferable that the rigidity imparting body 13 is not fixed except for the distal end portion and the proximal end portion. By not fixing the intermediate portion of the rigidity imparting body 13, when the distal end portion of the catheter bends, the rigidity imparting body 13 shifts into the second lumen and does not hinder the flexibility of the distal end portion of the catheter, which is preferable.

The expansion body 3 is foldable, and can be folded around the outer circumference of the inner tube 1 when it is not expanded. The expandable body 3 is a foldable body having a substantially cylindrical portion 3a of substantially the same diameter, at least a part of which has a substantially cylindrical shape so that the narrowed portion of the blood vessel can be easily expanded. The above-mentioned substantially cylindrical portion does not have to be a perfect cylinder, and may be a polygonal prism. The rear end 8 of the expansion body 3 is liquid-tightly fixed to the front end of the outer tube 2 by an adhesive or heat fusion. The tip portion 7 is also liquid-tightly fixed to the tip portion of the inner tube 1.

Further, as shown in FIG. 1, the tip end portion 7 projects toward the tip end side from the tip end of the inner tube 1, and the protruding tip end forms a rounded portion 7a. And this rounded portion 7a is
It forms the tip of the catheter. More specifically, the distal end of the distal end portion 7 of the expansion body 3 covers the outer surface and the distal end surface of the distal end portion of the inner pipe, and particularly the portion that covers the distal end face of the inner pipe 1 has a rounded shape. ing. With such a shape, the fixing distance between the distal end portion 7 of the expansion body 3 and the inner tube 1 can be reduced and the fixing area can be increased, peeling between the two can be prevented, and further the expansion body can be prevented. Since the fixed end between the tip part 7 of 3 and the inner tube 1 is not exposed on the outer surface of the catheter, it is possible to prevent the expansion body 3 from peeling off like the flipped end at both fixed ends when the catheter is inserted. Therefore, this prevents the catheter tip from damaging the inner wall of the blood vessel when the catheter advances in the blood vessel. As will be described later, the rounded portion 7a is formed by inserting a core rod into the inner tube 1 with a tip portion 7 that is liquid-tightly fixed to the inner tube 1, and then inserting a mold having a rounded inner surface to heat the mold. Therefore, it can be easily formed. Further, as the shape of the tip portion 7,
The shape having the roundness described above is preferable, but the diameter may be tapered toward the tip, or the tip may be the end face.

The 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 II-II of FIG. The expansion space 15 communicates with the second lumen 6 at the entire rear end thereof. 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 from the second lumen.
As a material for forming the expansion body 3, a material having a certain degree of flexibility is preferable, and examples thereof include polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, and cross-linking type. Ethylene-vinyl acetate copolymer, polyurethane, thermoplastic resin such as polyamide elastomer, silicone rubber, latex rubber and the like can be used, preferably the above-mentioned thermoplastic resin, more preferably cross-linked ethylene-vinyl acetate copolymer It is united.

Further, the expandable body 3 is tapered in the front and rear of the cylindrical portion 3a up to the above-mentioned fixed portions 7 and 8 with the inner pipe 1 and the outer pipe 2. Regarding the size of the expansion body 3, the outer diameter of the cylindrical portion when expanded is 1.00 to 3
5.00 mm, preferably 1.50-30.00 mm, length 3.00
~ 80.00mm, preferably 10.00 ~ 75.00mm, the total length of the expansion body 3 is 5.00 ~ 120.00mm, preferably 15.00 ~ 1
It is 00.00 mm.

The outer surface of the inner pipe 1, a position near the rear end side of the fixed portion of the expansion body 3 with the inner pipe 1, and a position near the distal end side of the fixed portion of the expansion body 3 and the outer pipe 2, Cylindrical part 3a of the expansion body 3
X-ray opaque material (for example, gold, platinum, tungsten or alloys thereof, or silver) having a length equal to that of the cylindrical portion 3a of the expansion body 3 at both ends. -Palladium alloy or the like) is preferably provided with the marker 14. Further, as shown in FIG. 1, the shape of the marker 14 is preferably a coil spring, and it is more preferable that the marker 14 is tightly wound by 1 to 4 mm, preferably 2 to 3 mm from both ends. . This is because it is possible to easily confirm the position of the expansion body 3 under X-ray fluoroscopy, and by using a spring shape, it is possible to prevent the bending and crushing of the bending portion of the inner tube located in the expansion body. A reinforcing body is formed, which is preferable.

In particular, if the marker 14 is formed of one spring coil and wound around the outer circumference of the inner tube 1 by tight winding, the proof strength against external force becomes stronger. Further, if the cross-sectional shape of the coil-shaped linear body is elliptical, rectangular or elliptical, the proof stress against external force becomes stronger.

The branch hub 20 has a first opening 9 that communicates with the first lumen 4 and forms a guide wire port, and communicates with the inner tube hub 22 fixed to the inner tube 1 and the second lumen for injection. It has a second opening 11 forming a port and is composed of an outer tube hub 23 fixed to the outer tube 2. The outer tube hub 23 and the inner tube hub 22 are fixed to each other. As a material for forming this branch hub, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be preferably used. A sectional view of one embodiment of the branch hub 20 is shown in FIG. In this embodiment, a bend preventing tube 50 is provided at the end of the outer tube 2. The bending prevention tube 50 is heat-shrinkable, and is formed such that the inner diameter after heat shrinkage is slightly smaller than the outer diameter of the outer tube 2, and the heat-shrinkable tube 50 is formed into the outer tube 2. It can be easily attached by fitting it on the end portion and heating (for example, applying hot air) to shrink the end portion. The bending prevention tube 50 is fixed to the outer tube hub 23 by a stop pin 52. In this fixing method, the outer diameter of the portion other than the rear end portion is approximately equal to the inner diameter of the outer pipe 2 at the rear end of the outer pipe 2, and a stop pin 52 having an enlarged rear end portion is inserted to fix the outer pipe 2 to the outer pipe 2. It is carried out by inserting it from the tip into the outer tube hub 23 and pushing the protrusion 54 provided on the inner surface of the outer tube hub 23 until the rear end portion of the stop pin 52 is crossed. Further, an adhesive may be applied to the contact surface between the outer tube hub 23 and the bending preventing tube 50 to fix the tube. As a material for forming the outer tube hub, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be preferably used.

At the end of the inner pipe 1, a bend prevention tube 60
have. 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 1, and the heat-shrinkable tube 60 is attached to the end portion of the inner tube 1. It can be easily attached by fitting, heating (for example, applying hot air) and contracting. Then, the base end portion of the rigidity imparting resistance 13 is fixed to the outer surface of the inner pipe 1 by the contraction tube 60. Providing rigidity
The base end of 13 does not necessarily have to be fixed. The inner pipe 1 to which the bending preventing tube 60 is attached is fixed to the inner pipe hub 22. In this fixing method, the outer diameter of the portion other than the rear end portion is substantially equal to the inner diameter of the inner pipe 1 at the rear end of the inner pipe 1, and a stopper pin 62 having a rear end portion having an enlarged diameter is inserted,
Insert the inner pipe 1 from its tip into the inner pipe hub 22,
The projection 64 provided on the inner surface of the stopper pin 62 is pushed in until the rear end portion of the stopper pin 62 crosses over. Further, an adhesive may be applied to the contact surface between the inner tube hub 22 and the bending preventing tube 60 to fix the tube. As a material for forming the inner tube hub, polycarbonate, polyamide, polysulfone,
Thermoplastic resins such as polyarylate and methacrylate-butylene-styrene copolymer can be preferably used. Then, as shown in FIG. 6, the inner pipe hub 22 and the outer pipe hub 23 are fixed. This fixing is performed by inserting the inner pipe 1 from the rear end of the outer pipe hub 23 attached to the base end portion of the outer pipe 2 and joining the inner pipe 1 from the rear end thereof. Further, at this time, by applying an adhesive to the joint portion between the inner pipe hub 22 and the outer pipe hub 23, it is possible to surely fix the both.

Alternatively, instead of providing the branch hub, a tube having a port member having an opening at the rear end may be liquid-tightly attached to each of the first lumen and the second lumen.

Next, a method for manufacturing the catheter with an expandable body of the present invention will be described with reference to the embodiments shown in the drawings.

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

The catheter with an expandable body is provided coaxially with the inner tube 1 having a first lumen 4 whose tip is open,
An outer tube 2 which is provided at a position retracted from the tip of the inner tube 1 by a predetermined length and forms a second lumen 6 between the inner tube 1 and the outer surface thereof;
A proximal end portion 8 having a distal end portion 7 and a proximal end portion 8 is attached to the outer pipe 2, and the distal end portion 7 is attached so as to project from the inner pipe 1 toward the distal end side to form the distal end of the catheter, near the proximal end portion. Foldable expansion body 3 communicating with the second lumen 6 at
And a first opening 9 provided at the base end of the inner pipe 1 communicating with the first lumen 4, and a first opening 9 provided at the base end of the outer pipe 2 communicating with the second lumen 6. Second opening 11 and second
And a rigidity imparting body 13 which is provided in the lumen 6 and extends in the axial direction to impart rigidity.

Hereinafter, description will be given with reference to the drawings.

Next, a method for manufacturing the catheter with an expandable body of the present invention will be described with reference to the drawings.

The manufacturing method of the present invention comprises a step of molding an inner tube having a lumen opened from the front end to the rear end, and a lumen opened from the front end to the rear end, and the inner diameter is larger than the outer diameter of the inner pipe, and A step of forming an outer tube shorter than the inner tube by a predetermined length, a step of forming a contractable or foldable expansion body having a distal end portion and a proximal end portion, a step of inserting the inner tube into the outer tube, The step of fixing the base end portion of the expansion body to the tip end portion of the outer tube, the step of fixing the tip end portion of the expansion body to the tip end portion of the inner tube, and the heat processing of the tip end portion of the fixed expansion body , Forming the tip of the catheter.

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

The step of forming the inner tube 1 having the first lumen 4 communicating from the front end to the rear end is performed by a method of cutting the extruded thermoplastic resin forming the inner tube into a predetermined length or by injection molding. It is formed by the method.

Then, the step of molding the outer tube 2 has a step of molding the front end side outer tube 2a having a lumen penetrating from the front end to the rear end, an outer diameter larger than the outer diameter of the front end side outer tube 2a, and A proximal outer tube 2b having a lumen extending from the front end to the rear end
, A step of forming one end of the proximal end side outer tube 2b in a taper shape, a step of expanding one end of the tip end side outer tube 2a, and a base end outer tube outer tube 2b formed in a taper shape. And a step of fixing the tapered end portion and the diameter-expanded end portion of the diameter-increased tip-side outer tube 2a.

Next, a step of forming a contractable or foldable expansion body having a distal end portion and a proximal end portion will be described.

The expansion body 3 preferably has flexibility, for example,
Polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer and other polyolefins, polyvinyl chloride, thermoplastic resins such as polyurethane, more preferably cross-linked ethylene -Can be formed using a vinyl acetate copolymer. For example, a tube made of a thermoplastic resin for forming the expansion body 3 is formed, a tube holder is attached to the end of the tube, and the lumen of the tube is closed in the vicinity of the tube holder. Then, the closed tube is pulled in the opposite direction by applying a load to the tube holder to remove the slack of the tube, and the portion forming the expansion body is heated by the heating device in the vicinity of the melting point of the material forming the tube. Heat up to. Keeping the tube heated, fit the lumen into the mold tube formed with the expanded body expanded, send gas into the tube while pressurizing it, and heat it in the mold The part of the tube is attached to the inner wall of the mold. Then, the tube is left in a pressurized state until it returns to room temperature, then the inside of the tube is made a negative pressure, the portion to be the expansion body is contracted, and the mold is removed. Then, the expansion body can be formed by cutting the tube at the front end portion and the rear end portion of the tube.

Further, at least the distal end portion and the proximal end portion of the expansion body are
If the expansion body 3 is heat-shrinkable, it can be easily attached to the outer tube 2 and the inner tube 1 by using the heat-shrinkable body. As a method of imparting heat shrinkability to at least the distal end portion and the proximal end portion of the expansion body, it is not limited to a method of forming the expansion body with a crosslinkable thermoplastic resin, or a method using a crosslinkable resin, In the forming step, if the expansion body is formed by heating at a temperature at which strain remains, the expansion body can have heat shrinkability.
Furthermore, after forming the inner diameter of the distal end of the expander slightly smaller than the outer diameter of the inner pipe, and further forming the base end slightly smaller than the outer diameter of the outer pipe, expand both ends of the expander (by stretching). It can be made to have heat shrinkability.

The step of forming the expansion body may be performed at any time, and the order of the step of forming the inner tube and the outer tube may be arbitrary.

Next, the step of providing the opening 11 communicating with the lumen 6 of the outer tube at the base end of the outer tube 2 will be described. The opening 11 is preferably made by attaching an outer tube hub 23 having an opening to the base end of the outer tube 2. This case will be described as an example with reference to FIG.

First, the bending preventing tube 50 is attached to the end portion of the outer tube 2. As this attachment method, a bend-preventing tube 50 having heat shrinkability is used, and the heat shrinkable tube 50 formed so that the inner diameter after heat shrinkage is slightly smaller than the outer diameter of the outer tube 2 is removed. The tube 2 can be attached by being fitted on the end portion of the tube 2 and heated (for example, hot air is blown) to shrink the tube. Then, the outer pipe hub 23 is attached to the outer pipe 2 to which the bending preventing tube 50 is attached. In this mounting method, the outer diameter of the portion other than the rear end portion is substantially equal to the inner diameter of the outer tube 2 at the rear end of the outer tube 2,
A stopper pin 52 having an enlarged rear end portion is inserted, the outer pipe 2 is inserted into the outer pipe hub 23 from its tip, and a projection 54 provided on the inner surface of the outer pipe hub 23 is attached to the rear end of the stop pin 52. Install by pushing in until the part crosses. In addition, the outer tube hub
An adhesive may be applied to the contact surface between 23 and the bending preventing tube 50 to fix the tube. As a material for forming the outer tube hub, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be preferably used.

The step of providing the opening 11 communicating with the lumen 6 of the outer tube 2 at the base end portion of the outer tube 2 may be performed at any time after the outer tube 2 is formed. Preferably, it is performed after performing the step of fixing the proximal end portion of the expansion body 3 to the distal end portion of the outer tube 2 described later. The inner tube 1 may be formed in any order.

Next, the step of providing the opening 9 communicating with the lumen of the inner pipe 1 at the base end of the inner pipe 1 will be described. The opening 9 is
It is preferable to attach the inner pipe hub 22 having the first opening 9 to the base end of the outer pipe 2. This case will be described as an example with reference to FIG.

First, the bending preventing tube 60 is attached to the end portion of the inner tube 1. As this attachment method, a heat shrinkable tube is used, and the shrinkable tube is formed such that the inner diameter after heat shrinkage is slightly smaller than the outer diameter of the inner tube 1.
This can be easily performed by fitting 60 onto the end portion of the inner pipe 1 and heating (for example, applying hot air) to shrink the inner pipe 1. Further, in the embodiment shown in FIG. 6, a stiffness imparting body 13 is provided between the inner pipe 1 and the outer pipe 2, and the end portion of this stiffness imparting body 13 has a prevention tube 60 and an inner pipe 2. By performing the above-mentioned heat treatment after the tube 60 is placed 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 inner tube hub 22 is attached to the inner tube 1 to which the bending preventing tube 60 and the rigidity imparting body 13 are attached. In this mounting method, the outer diameter of the portion other than the rear end portion is substantially equal to the inner diameter of the inner pipe 1 at the rear end of the inner pipe 1, and a stop pin 62 having an enlarged rear end portion is inserted to fix the inner pipe 1 Inner tube hub from the tip 22
Then, the projection 64 provided on the inner surface of the inner tube hub 22 is pushed in until the rear end portion of the stop pin 62 is pushed over to attach the hub. Furthermore, an adhesive may be applied to the contact surface between the inner tube hub 22 and the bending prevention tube 60 to fix the tube 60. As a material for forming the inner tube hub, the same material as the outer tube hub can be preferably used.

The step of providing the opening 9 communicating with the lumen 4 of the inner pipe 1 at the base end portion of the inner pipe 1 may be performed at any time after the inner pipe 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 portion of the outer tube 2, and the step of forming the expansion body 3? Good.

Next, a process of fixing the base end portion 8 of the expansion body 3 to the tip end portion of the outer tube 2 will be described.

As a method of fixing the base end portion 8 of the expansion body 3 to the distal end portion of the outer tube 2, a cored bar having an outer diameter that is substantially equal to or slightly smaller than the inner diameter of the outer tube 2 than the front end or the rear end of the outer tube 2 is used. The core body is inserted so that the end portion of the base end portion 8 of the expansion body 3 on the tip end side of the core 3 is aligned with the tip of the outer tube 2. Then, the glass mold for joining is fitted so as to be located on the base end portion 8 of the expansion body 3, and the glass mold is heated by the heating device to expand the expansion body 3
The base end portion 8 of is fixed to the tip end portion of the outer tube 2. If the base end portion 8 of the expansion body 3 is formed so as to have a heat shrinkability, the expansion body 3 is heat-shrinked by heating by the above glass mold, so that it can be easily fixed. Base part 8 of the expansion body 3
After fixing the glass mold to the tip of the outer tube 2, the glass mold is left to reach room temperature, the glass mold is retracted from the joint, and the core metal is removed to remove the base metal 8 and the outer tube. The tip end of 3 can be easily fixed.

Further, although the glass mold is used in the above description, the invention is not limited to this,
For example, a die for joining may be used. Alternatively, a metal cored bar may be used to fit an electrode for high frequency transmission on the base end portion 8 of the expansion body 3, and the electrode may be fixed by fusing by high frequency induction heating. You may fuse together.

The step of fixing the base 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 outer tube 1 and the expansion body 3 are formed. The step of forming the inner tube 1 and the step of providing the opening 9 communicating with the lumen 4 of the inner tube at the base end portion of the inner tube 1 may be performed in any order.

Next, an inner pipe hub 22 having an opening attached to the base end of the inner pipe 1 and an outer pipe hub attached to the base end of the outer pipe 1.
The step of fixing 23 and 23 will be described.

As shown in FIG. 6, the inner pipe 1 is inserted from the tip end thereof from the rear end of the outer pipe hub 23 attached to the base end portion of the outer pipe 2.
At this time, in order to prevent the inner pipe 1 from being bent, a core metal is inserted into the inner pipe 1, and as shown in FIG.
The front end portion of is inserted into the rear end of the outer tube hub 23 and joined. Further, at this time, by applying an adhesive to the joint portion between the inner pipe hub 22 and the outer pipe hub 23, it is possible to surely fix the both.

An inner pipe hub 22 having an opening attached to the base end of the inner pipe 1 and an outer pipe hub 23 attached to the base end of the outer pipe 1.
The steps of fixing and are the steps of forming the inner tube 1, the step of providing the inner tube hub 22 at the base end of the inner tube 1, the step of forming the outer tube 1 and the outer tube hub at the base end of the outer tube 2. It may be after performing the step of providing 23. It is preferable to carry out after forming the expansion body 3 and fixing the expansion body 3 to the outer tube 1.

Next, a description will be given of a step of fixing the distal end portion 7 of the expansion body 3 to the distal end portion of the inner pipe 1 and a step of heating the distal end portion of the fixed expansion body.

As a method of fixing the tip of the expansion body 3 to the tip of the inner tube 1, as shown in FIG. 8, the expansion body 3 and the outer tube 2 are fixed to each other and attached to the base end of the inner tube 1. The inner tube hub 22,
An example will be described below after the outer tube hub 23 attached to the base end of the outer tube 2 is fixed.

As shown in FIG. 7, a core rod having an outer diameter that is substantially equal to or slightly smaller than the inner diameter of the inner pipe 1 than the front or rear end of the inner pipe 1.
Insert 80 so that it projects 10 to 15 mm from the tip of the inner tube 1. Further, as shown in FIG. 8, the expansion body 3 is fixed to the distal end portion of the outer tube 2, the outer tube hub 23 is attached to the proximal end portion of the outer tube 2, and the inner tube into which the core rod 80 is inserted is inserted. Since the inner pipe hub 22 that is inserted from the distal end side of the inner pipe 1 and attached to the base end portion of the inner pipe 1 is fixed to the outer pipe hub 23, the inner pipe 1 is the distal end of the outer pipe 2 and further the expansion body 3 Is protruding from the tip of
It is adapted to be located in the tip extension portion 77 of the expansion body 3. Next, as shown in FIG. 9, the glass mold 82 for joining is located on the tip end side of the extension body 3 from the tip end side of the tip extension part 77 of the extension body 3 and further from the tip end side of the core rod 80. As described above, the glass mold 82 is heated by a heating device (not shown) to fix the distal end portion 7 of the expansion body 3 to the distal end portion of the inner tube 1.
Preferably, if the tip end portion 7 of the expansion body 3 is formed so as to have a heat-shrinking property, it is naturally heat-shrinked by the heating by the above-mentioned glass mold 82, so that it can be easily fixed. In this way, after the distal end portion 7 of the expandable body 3 is fixed to the distal end portion of the inner tube 1, the glass mold 82 is left to reach room temperature, and the glass mold 82 is retracted and removed from the joint portion to expand the expandable body. The tip 7 of the inner tube 1 and the tip 7 of the inner tube 3 can be fixed to each other.

Further, although the glass mold is used in the above description, the invention is not limited to this,
For example, a die for joining may be used, or a metal rod may be used for the core rod 80, an electrode for high frequency transmission may be fitted to the distal end portion 7 of the expansion body 3, and the core rod 80 may be fixed by fusion by high frequency. Alternatively, ultrasonic waves may be used for fusion.

Then, the fixed expansion body is cut by a predetermined length longer than the tip of the catheter. In this step, as shown in FIG. 10, the distal end extension portion 77 of the expandable body 3 is cut at an arrow AA on the distal end side about 1 mm from the distal end of the inner tube. The cutting can be performed neatly by using a cutting tool such as a razor along the circumferential direction of the core rod 88.

Then, next, a portion longer by a predetermined length than the catheter is heat-processed. As described above, the catheter whose tip portion has been cut to a predetermined length is inserted into the heat treatment mold 96 and pushed until it hits, as shown in FIG. The heat treatment mold 96 has a cylindrical recess 97 having an inner diameter approximately equal to the outer diameter of the joint portion between the distal end portion 7 of the expansion body 3 and the inner pipe 1, and the core rod is provided on the bottom surface of the center portion of the recess 97. A hole portion 98 through which 80 can be inserted is provided. Furthermore, the bottom surface of the cylindrical recess 97 has a required shape (for example, a shape with rounded corners for roundness) by heat-treating a portion that is longer than the catheter by a predetermined length. After the heat treatment, the catheter tip is rounded. And heat treatment type
By heating 96 and further pressing it in the direction toward the tip, the tip extension portion 77 corresponding to a portion having a predetermined long length becomes in a molten state, the molten portion is deformed according to the shape of the bottom surface of the recess 97, and the inner pipe 1 Flows into a space formed between the tip of the catheter and the tip extension portion 77 to form a rounded portion 7a at the tip of the catheter. Then, as shown in FIG. 12, the heat treatment mold 96 having the distal end portion of the catheter inserted therein is cooled. As a cooling method, a heat treatment mold 96 that has been heated and warmed is placed in a cooling container 99 that stores a coolant such as cold water, and the heat treatment mold 96 is left as it is until it is sufficiently cooled. Then, after the heat treatment mold 96 is sufficiently cooled, it is taken out from the cooling container 99, and the heat treatment mold 96 is
By removing and pulling out the core rod 80 from the inner pipe 1,
As shown in FIG. 13, a catheter with a dilator having a rounded portion 7a formed at its tip is manufactured.

[Operation] Next, the operation of the catheter with an expandable body of the present invention will be described with reference to FIGS. 14 to 18 using the catheter with an expandable body of the embodiment shown in FIGS. 1 to 6. To do.

It is preferable to remove as much air as possible from the catheter with the dilator before performing the dilatation treatment of the stenosis generated in the blood vessel. Therefore, the second opening 11 of the catheter of the present invention
A suction or injection means such as a syringe is attached to the syringe, a liquid (vascular contrast agent) is put into the syringe, suction and injection are repeated to remove the air in the second lumen and the dilator and replace it with the liquid.

When inserting the catheter with an expandable body, first secure the blood vessel by the Seldinger method or the like, then pay attention to the guide wire for the guide catheter (not shown) inside the blood vessel, and insert the guide catheter 30 into the blood vessel along it. As shown in FIG. 15, pay attention to the guide catheter 30 at the coronary artery entrance 32 having the target lesion and remove the guide wire for the guide catheter. As shown in FIG. 14, the catheter 40 with an expandable body of the present invention in which the guide wire 34 for a catheter with an expandable body is inserted through the Y-shaped connector 50 provided at the rear end of the guide catheter 30, and the expandable body is inserted. With catheter 40
Number of guide wires for catheter with dilator 34 from the tip of
Insert it into the blood vessel while protruding cm. The catheter 40 with the expandable body advances through the guide catheter 30, enters the blood vessel 35 having the target lesion area from the tip of the guide catheter 30 as shown in FIG. And pass it through the constriction 36 and take note. The catheter 40 with an expandable body advances in the blood vessel 35 along the guide wire 34 for a catheter with an expandable body. The catheter with a dilator 40 that has reached the stenosis 36 is
As shown in the figure, the X-ray opaque marker 14 provided on the inner tube 1 is used as a mark to locate the expansion body 3 in the stenosis 36 under fluoroscopy. After that, an angiographic agent is injected at a pressure of several atmospheres to several tens of atmospheres with an injector 54 having a pressure gauge connected to the second opening forming the injection port of the catheter 40 with an expandable body, as shown in FIG. Then, the narrowed portion 36 is compressed and opened. Then, the peripheral blood flow is confirmed by injecting a contrast agent from the contrast agent injection port 52 of the Y-shaped connector 50 of the guide catheter 30 and performing X-ray imaging. If improvement of blood flow is recognized, the catheter with dilator 40 and the guide wire for catheter with dilator 34 are removed, and then the guide catheter is removed, and the hemostasis by compression is completed to complete the procedure.

[Effects of the Invention] A catheter with an expandable body of the present invention is provided coaxially with an inner tube having a first lumen whose tip is open, and is retracted by a predetermined length from the tip of the inner tube. Is provided in the position
An outer tube forming a second lumen between the inner tube and an outer surface of the inner tube, a distal end portion and a proximal end portion, the proximal end portion being attached to the outer pipe, and the distal end portion being attached to the inner pipe. A catheter with an expander attached to the inner tube, wherein the expandable body has a foldable expander communicating with the second lumen in the vicinity of the proximal end, and the distal end of the expander attached to the inner tube is the inner tube. Since it projects more toward the distal end than the distal end side and forms the distal end portion of the catheter, the fixing distance between the distal end portion of the expansion body and the inner tube can be reduced and the fixing area can be increased. The peeling can be prevented, and the fixed end between the distal end of the dilator and the inner tube is not exposed on the outer surface of the catheter.
When the catheter is inserted, peeling can be prevented so that the expansion body turns over at the fixed ends of both. Therefore, when the catheter advances in 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 comprises a step of forming an inner tube having a lumen opened from the front end to the rear end, and a lumen opening from the front end to the rear end, and the outer diameter of the inner pipe. 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 contractable or foldable expansion body having a distal end portion and a proximal end portion,
Inserting the inner pipe into the outer pipe, fixing the base end of the expansion body to the distal end of the outer pipe, and fixing one end of the fixed expansion body to a predetermined length from the tip of the inner pipe. A step of cutting long, and a step of heat-processing the portion longer than the inner tube by a predetermined length, and forming the tip of the catheter by coating the outer surface and the tip of the inner tube with the tip of the expander. Therefore, the catheter with the expandable body can be reliably manufactured, and the distal end portion of the expandable body and the distal end portion of the catheter are integrated, and can be easily manufactured without using another member. You can

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a distal end portion of an embodiment of a catheter with an expandable body of the present invention, and FIG. 2 is a drawing showing a base end portion of an embodiment of a catheter with an expandable body of the present invention. 1 is a sectional view of an intermediate portion of an embodiment of the catheter with an expandable body of the present invention, FIG. 4 is a sectional view taken along the line I-I in FIG. 1, and FIG. 5 is a line II-II in FIG. Sectional views, FIG. 6 is a sectional view of a proximal end portion of an embodiment of the catheter with an expandable body of the present invention, and FIGS. 7 to 13 are for explaining a method for manufacturing the catheter with an expandable body of the present invention. FIGS. 14 to 18 are views showing the operation of the catheter with an expandable body of the present invention. 1 ... Inner tube, 2 ... Outer tube, 3 Expander, 4 ... First lumen, 6 ... Second lumen, 9 ... First opening, 11 ... Second opening, 13 ...... Stiffener 14 ...... Marker 20 ...... Branch hub, 22 …… Inner tube hub 23 …… Outer tube hub, 77 …… Tip extension 80 …… Core rod, 96 …… Heat treatment type

Claims (4)

[Claims] 1. An inner pipe having a first lumen whose tip is open, and an inner pipe provided coaxially with the inner pipe and at a position retracted from the tip of the inner pipe by a predetermined length. An outer tube forming a second lumen between the outer tube and the outer surface; a distal end portion and a proximal end portion, the proximal end portion being attached to the outer pipe, the distal end portion being attached to the inner pipe; A catheter with an expander having a foldable expander communicating with the second lumen near the proximal end, wherein the distal end of the expander attached to the inner tube is more distal than the inner tube. A catheter with an expander, wherein the catheter with an expander is formed so as to project into a portion to form a tip of the catheter with an expander. 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. The catheter with an expandable body according to claim 1, wherein the distal end of the expandable body has a rounded shape. 4. A step of molding an inner tube having a lumen opened from the front end to the rear end, and a lumen having an lumen opened from the front end to the rear end, the inner diameter being larger than the outer diameter of the inner pipe, A step of forming an outer tube having a shorter predetermined length, a step of forming a contractable or foldable expansion body having a distal end portion and a base end portion, a step of inserting the inner tube into the outer tube, A step of fixing the base end portion of the expansion body to the distal end portion, a step of cutting one end of the fixed expansion body longer than the tip end of the inner pipe by a predetermined length, and a portion longer by the predetermined length than the inner pipe. A method of manufacturing a catheter with an expandable body, which comprises the step of performing heat processing to cover the outer surface and the distal end surface of the inner tube with the distal end portion of the expandable body to form the distal end portion of the catheter.