JP2002291900A - Medical tool and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical tool that helps minimize the outside diameter of a tube portion to which a metal ring is attached and can be easily inserted into a celom, and a method for manufacturing the medical tool that can very easily manufacture the medical tool without causing a defect to the tube portion. SOLUTION: After forcibly reducing the outside diameter of a synthetic resin tube 12 of a prescribed length range including a position in which the metal ring 15 is mounted and forming a reduced diameter portion 58 having an outside diameter equal to or smaller than the inside diameter of the metal ring 15, by mounting the metal ring 15 to the reduced diameter portion 58 and heating, the outside diameter of the reduced diameter portion 58 is restored, and the metal ring 15 is fixed to a prescribed position of the tube 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical device such as a balloon catheter and a method for manufacturing the same, and more particularly, to a medical device to which a metal ring used as an electrode or a sensor is attached, or a method for X-ray imaging. The present invention relates to a medical device to which a contrast ring is attached and a method for manufacturing the same.

[0002]

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

[0003] In order to treat a stenosis in a blood vessel, the stenosis is inserted into the blood vessel, the balloon is inflated to expand the stenosis, and the blood flow on the peripheral side of the stenosis is improved.
As a so-called PTCA balloon catheter, an over-the-wire balloon catheter and a monorail balloon catheter (for example, JP-A-2000-21)
7923). In any of these types of balloon catheters, a guide wire is first passed through the stenosis in the blood vessel, and then the balloon catheter is sent to the stenosis along the guide wire, and the balloon is inflated to inflate the stenosis. To expand.

[0004] In many of the conventional balloon catheters including such a PTCA balloon catheter, an inner tube is arranged inside an outer tube constituting a catheter tube. The lumen of the inner tube is used as a guide wire insertion hole, and the distal end of the balloon is heat-sealed to the outer periphery of the distal end of the inner tube, thereby sealing the inside of the balloon.

In a conventional balloon catheter, in order to grasp the position of the PTCA balloon catheter inserted into a blood vessel, a contrast ring made of tungsten or the like is provided on the outer periphery of an inner tube located inside the balloon portion. Installed. In general, since the contrast ring is fitted from the outside of the inner tube, the outer diameter of that portion becomes larger than the outer diameter of the inner tube, and the shape of the inner tube becomes extremely convex. For this reason, it may be an obstacle when trying to pass a balloon catheter in a state where the balloon portion is folded to a stenotic portion of a blood vessel.

As disclosed in JP-A-8-289934, a structure has been proposed in which a concave groove is provided at a predetermined position of an inner tube by a processing means such as etching, and a contrast ring is attached to the concave groove. However, in the balloon catheter having this structure, when a concave groove is formed on the outer periphery of the extremely thin inner tube, the inner tube is too thin and a defect easily occurs in the inner tube. Also, it is difficult to attach a contrast ring to the groove after machining the groove in the inner tube.

In medical instruments other than balloon catheters, there are medical instruments in which a metal ring used as an electrode or a sensor is attached to the outer periphery of a synthetic resin tube in addition to a use such as a contrast ring. Have the same disadvantages as balloon catheters.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is an object of the present invention to minimize the outer diameter of a tube portion to which a metal ring is attached, and to improve the insertion into a body cavity. Excellent medical equipment and the medical equipment,
It is an object of the present invention to provide a method for manufacturing a medical device which can be manufactured very easily without causing a defect in a tube.

A second object of the present invention is to make it possible to easily insert the distal end of a balloon catheter even in a case where the degree of stenosis is severe or in a stenotic portion of a meandering blood vessel. An object of the present invention is to provide a balloon catheter having excellent insertion characteristics and a method for manufacturing the balloon catheter which can extremely easily manufacture the balloon catheter without causing a defect in the inner tube.

[0010]

In order to achieve the first object, a medical instrument according to the present invention forcibly regulates the outer diameter of a synthetic resin tube within a predetermined length range including a position where a metal ring is mounted. After reducing the diameter, forming a reduced diameter portion having an outer diameter equal to or less than the inner diameter of the metal ring, attaching a metal ring to the reduced diameter portion, and then, by heating, the reduced diameter portion of the The outer diameter is restored, and the metal ring is fixed to a predetermined position of the tube.

Preferably, the ratio of the outer diameter of the tube after restoration to the outer diameter of the metal ring is 0.7 to 1.

Preferably, the ratio of the outer diameter of the tube after restoration to the inner diameter of the metal ring is 1 to 1.2.

In the method for manufacturing a medical device according to the present invention, the outer diameter of the synthetic resin tube in a predetermined length range including the position where the metal ring is mounted is forcibly reduced, and is equal to or less than the inner diameter of the metal ring. After forming the reduced diameter portion having an outer diameter of, a metal ring is attached to the reduced diameter portion, and thereafter, the outer diameter of the reduced diameter portion is restored by heating, and the metal ring is fixed to the predetermined diameter of the tube. It is characterized by being fixed at a position.

[0014] Preferably, the heating temperature of the reduced diameter portion is in a range of about 5 to 20 ° C lower than the melting point of the synthetic resin constituting the tube.

Preferably, the reduced diameter portion is formed by axially pulling a distal end of the tube.

Preferably, the reduced diameter portion is formed with a mandrel inserted into the lumen of the tube.

In order to achieve the second object, a balloon catheter according to the present invention comprises an outer tube having at least one lumen for balloon expansion formed along a longitudinal direction, and a distal end of the outer tube. The proximal end sealing portion of the balloon portion is joined to the portion, the balloon portion communicating with the interior of the balloon expansion lumen, and the balloon portion so as to form a sealed expansion space inside the balloon portion. A distal end sealing portion is joined to the distal end of the inner tube;
An inner tube extending in the axial direction inside the balloon portion and inside the balloon expansion lumen of the outer tube,
A balloon catheter having at least one contrast ring attached to an outer peripheral portion of the inner tube located inside the balloon portion, wherein the inner tube has a predetermined length range including a position where the contrast ring is attached. By forcibly reducing the outer diameter of the, after forming a reduced diameter portion having an outer diameter equal to or less than the inner diameter of the imaging ring, by attaching a contrast ring to the reduced diameter portion, and then, by heating, The outer diameter of the reduced diameter portion is restored, and the contrast ring is fixed to a predetermined position of the inner tube.

Preferably, the ratio of the outer diameter of the inner tube after restoration to the outer diameter of the contrast ring is 0.7 to 1.

Preferably, the ratio of the outer diameter of the inner tube after restoration to the inner diameter of the contrast ring is 1 to 1.2.

A method of manufacturing a balloon catheter according to the present invention includes the steps of: providing an outer tube having at least one balloon inflation lumen formed along a longitudinal direction; and a distal end of the outer tube at a proximal end of the balloon portion. A balloon portion, to which a sealing portion is joined, and which communicates with the balloon expansion lumen, and a distal end sealing portion of the balloon portion are formed so as to form a sealed expansion space inside the balloon portion. An inner tube joined to a distal end of a tube and extending axially inside the balloon portion and inside a balloon expansion lumen of the outer tube; and an inner tube located inside the balloon portion. A method of manufacturing a balloon catheter having at least one contrast ring mounted on an outer peripheral portion, wherein the predetermined length range includes a position where the contrast ring is mounted. The outer diameter of the inner tube is forcibly reduced, and after forming a reduced diameter portion having an outer diameter equal to or less than the inner diameter of the contrast ring, at least one contrast ring is attached to the reduced diameter portion, By heating, the outer diameter of the reduced diameter portion is restored, and the contrast ring is fixed at a predetermined position of the inner tube.

Preferably, the heating temperature of the reduced diameter portion is 5 to 20 ° C. from the melting point of the synthetic resin forming the inner tube.
It is in the low temperature range.

[0022] Preferably, the reduced diameter portion is formed by axially pulling a distal end of the inner tube.

Preferably, the reduced diameter portion is formed with a mandrel inserted inside the lumen of the inner tube.

[0024]

In the method for manufacturing a medical device according to the present invention, the outer diameter of the synthetic resin tube in a predetermined length range including the position where the metal ring is mounted is forcibly reduced, and the outer diameter of the synthetic resin tube is equal to or less than the inner diameter of the metal ring. Since the reduced diameter portion having the outer diameter is formed, it is easy to attach the metal ring to the reduced diameter portion of the tube. By attaching a metal ring to the reduced diameter portion and then heating, the outer diameter of the reduced diameter portion is restored to near the original outer diameter. Therefore, the metal ring has a structure embedded in the outer periphery of the inner tube, and is fixed at a predetermined position.

The medical device thus manufactured has a structure in which the metal ring is embedded in the outer periphery of the inner tube, and the metal ring does not excessively protrude from the outer periphery of the tube at the mounting position of the metal ring. As a result, the outer diameter of the portion where the metal ring is mounted can be reduced, and the insertion characteristics of the medical device are improved.

In the method for manufacturing a medical device according to the present invention, the medical device according to the present invention can be manufactured relatively easily, the bonding strength between the metal ring and the tube is sufficient, and During the production, defects such as extremely thin tubes are unlikely to occur. Further, an adhesive or the like is not necessarily required for joining the metal ring and the tube.

In the method for manufacturing a balloon catheter according to the present invention, the outer diameter of the inner tube in a predetermined length range including the position where the contrast ring is mounted is forcibly reduced, and the inner diameter of the inner tube is equal to or less than the inner diameter of the contrast ring. Since the reduced diameter portion having the outer diameter is formed, the work of attaching the contrast ring to the reduced diameter portion of the inner tube is easy. By attaching a contrast ring to the reduced diameter portion and then heating, the outer diameter of the reduced diameter portion is restored to near the original outer diameter. Therefore, the contrast ring has a structure embedded in the outer periphery of the inner tube, and is fixed at a predetermined position.

The balloon catheter thus manufactured has a structure in which the contrast ring is embedded in the outer periphery of the inner tube, so that the contrast ring does not excessively protrude from the outer periphery of the inner tube at the mounting position of the contrast ring. . As a result, it is possible to reduce the outer diameter of the inner tube in a state where the balloon is folded around the inner tube. In particular, even when the degree of stenosis is severe or for a stenotic part of a tortuous blood vessel, a balloon catheter is used. Can be easily inserted. Therefore, the insertion characteristics of the balloon catheter are improved.

Further, in the method for manufacturing a balloon catheter according to the present invention, the balloon catheter according to the present invention can be manufactured relatively easily, the joint strength between the contrast ring and the inner tube is sufficient, and In the manufacture thereof, defects such as an extremely thin inner tube hardly occur. Also, an adhesive or the like is not necessarily required for joining the imaging ring and the inner tube.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings. The balloon catheter 2 according to the present embodiment shown in FIG. 1 is used for methods such as percutaneous coronary angioplasty (PTCA), dilation of a blood vessel such as a limb, dilation of an upper ureter, and renal vasodilation. It is used to dilate a stenosis formed in a blood vessel or other body cavity. In the following description, a case where the balloon catheter 2 of the present embodiment is used for PTCA will be described as an example.

The balloon catheter 2 for expansion according to the present embodiment
Is a so-called monorail type balloon catheter, which has a balloon portion 4, an outer tube 6 as a catheter tube, an inner tube 12, and a connector 8.

The balloon portion 4 shown in FIGS. 1 and 4 has a tubular portion 4a having an outer diameter larger than the outer diameter of the outer tube 6 in an expanded state. At both ends of the cylindrical portion 4a,
Contiguous tapered reduced diameter portions 4b and 4c and a proximal end sealing portion 5 and a distal end sealing portion 7 respectively following them are integrally formed. Proximal end seal 5
Has a smaller outer diameter than the tubular portion 4a so as to be connected to the outer peripheral portion of the distal end of the outer tube 6. Also, the distal end sealing portion 7 has a smaller outer diameter than the proximal end sealing portion 5 so as to be connected to the outer peripheral portion of the distal end of the inner tube 12.

The thickness of the balloon portion 4 is not particularly limited, but is 15 to 300 μm, preferably 30 to 150 μm. If the cylindrical portion 4a of the balloon portion 4 is cylindrical,
The shape is not particularly limited, and may be a cylinder or a polygonal cylinder. The outer diameter of the balloon portion 4 at the time of expansion is determined by factors such as the inner diameter of a blood vessel, and is usually about 1.5 to 10.0 mm, preferably 3 to 7 mm. This balloon part 4
The axial length of the cylindrical portion 4a is determined by factors such as the size of the intravascular stenosis, and is not particularly limited, but is 15 to 50 mm, preferably 20 to 40 mm. The balloon portion 4 before being expanded is folded and wound around the inner tube 12, and has an outer diameter as small as possible.

The material constituting the balloon portion 4 is preferably a material having a certain degree of flexibility. For example, ethylene and other α-olefins such as polyethylene, polyethylene terephthalate, polypropylene and ethylene-propylene copolymer are used. Copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride (PVC), cross-linked ethylene-vinyl acetate copolymer, polyurethane, polyamide,
Polyamide elastomer, polyimide, polyimide elastomer, silicone rubber, natural rubber, etc. can be used,
Preferred are polyethylene, polyethylene terephthalate and polyamide. The balloon portion 4 is made of a material and thickness that is more flexible than the tubes 6 and 12, so that the balloon portion 4 can expand and contract when a fluid is introduced therein.

As shown in FIG. 4, the proximal end sealing portion 5 of the balloon portion 4 has a first joint portion 5a which is overlapped and joined to the distal end portion of the outer tube 6, and the first joint portion 5a. A first non-joining portion 5b having substantially the same outer diameter as 5a and having no overlapping portion at the distal end of the outer tube 6 is provided. First joint portion 5a
Is joined to the outer periphery of the distal end portion of the outer tube 6 by means such as heat fusion or adhesion, so that the first lumen 10 of the outer tube 6 communicates with the internal expansion space of the balloon portion 4. ing. The distal end sealing portion 7 of the balloon portion 4 is joined to the outer periphery of the distal end portion of the inner tube 14 by means such as heat fusion or adhesion, and the internal expansion space of the balloon portion 4 is Other than the one lumen 10, it is sealed from the outside. The first lumen 10 of the outer tube 6 feeds fluid into the internal expansion space of the balloon portion 4 and
And a path for extracting fluid from the expansion space of the balloon section 4 and contracting the balloon section 4.

In the present embodiment, the axial length La of the first joint portion 5a in the proximal end sealing portion 5 of the balloon portion 4
Of the first non-joined portion 5b in the axial direction Lb (L
a: Lb) is 1: 1 to 1:10, more preferably,
It is in the range of 1: 2 to 1: 5. The axial length La of the first joint portion 5a is preferably 2 to 5 mm. Also, the first
The axial length Lb of the non-joined portion 5b is preferably 15 to
20 mm. If the axial length La of the first joining portion 5a is too short, joining tends to be insufficient, and if too long, the length of the overlapping portion tends to be long, and the flexibility at that portion tends to decrease. is there. Also, if the axial length Lb of the first non-joined portion 5b is too short, there is a tendency to have the same disadvantages as the conventional balloon catheter, and if it is too long, the strength of the balloon portion 4 tends to decrease. In addition, the total length Lc of the proximal end sealing portion 5 is preferably 17 to 25 mm.

As shown in FIG. 4, the inner tube 12 extends coaxially and axially in the expansion space of the balloon portion 4 and the inside of the distal end side first lumen 10 of the outer tube 6, and has a so-called coaxial catheter. It has a tube structure. A pair of contrast rings 15 are attached to the outer periphery of the inner tube 12 located inside the balloon portion 4, and when the balloon catheter 2 is inserted into a living body, X is applied from outside the living body.
The position of the contrast ring 15 can be contrasted with a line or the like. Examples of the material of the contrast ring 15 include metals such as gold, platinum, and tungsten.

The axial length L of each contrast ring 15
r is preferably 0.5 to 2 mm, more preferably 1
１．２1.2 mm. The distal end of the imaging ring 15 arranged on the distal end side of the balloon catheter 2 is located at a position corresponding to the intersection 4ac between the cylindrical portion 4a and the tapered reduced diameter portion 4c in the balloon portion 4. The proximal end of the imaging ring 15 disposed on the proximal end side of the balloon catheter 2 is located at a position corresponding to the intersection 4ab between the cylindrical portion 4a and the tapered reduced diameter portion 4b in the balloon portion 4. .

That is, the distance Ls from the distal end of the imaging ring 15 on the distal end side to the proximal end of the imaging ring 15 on the proximal end side corresponds to the length of the cylindrical portion 4a. Therefore,
By detecting the position of the pair of contrast rings 15 with X-rays or the like, the position of the cylindrical portion 4a in the balloon portion 4 can be accurately grasped. The cylindrical portion 4a is a portion that contributes to the expansion of a stenotic portion generated in a blood vessel or the like. These contrast rings 15 are embedded and fixed on the outer circumference of the inner tube 12 as shown in FIG. The embedding and fixing method will be described later.

As shown in FIG. 5, the distal end sealing portion 7 of the balloon portion 4 has a distal end tapered portion 7a whose outer diameter decreases toward the outer periphery of the distal end of the inner tube 12. It is. The distal end of the inner tube 12 protrudes in the axial direction further from the distal end of the tip taper portion 7a. A second joint portion 12a to which the distal end sealing portion 7 is joined and a second unjoined portion 12b which is not joined are formed.

In the present embodiment, the axial length L of the second joining portion 12a in the distal end sealing portion 7 of the balloon portion 4 is set.
The ratio (Ld: Le) of d to the axial length Le of the second non-joined portion 12b is in the range of 1: 2 to 4: 1, more preferably 1.5: 1 to 3: 1. . Second joint part 1
The axial length Ld of 2a is preferably 1.5 to 3 mm. The axial length Le of the second non-joined portion 12b is:
Preferably it is 0.5 to 1.5 mm. Second joint portion 12
If the axial length Ld of a is too short, the joining tends to be insufficient, and if it is too long, the length of the joining portion increases,
The flexibility in that part tends to decrease. Also, the second
If the axial length Le of the non-joining portion 12b is too short, it tends to have the same disadvantages as the conventional balloon catheter, and if it is too long, it tends to waste material and hinder the treatment. In addition, the total length Lf of the second joint portion 12a and the second non-joint portion 12b is preferably 3.5.
〜5.5 mm. In the present embodiment, a tapered tapered portion 12c is also formed on the outer periphery of the distal end of the inner tube 12.

A second lumen 14 is formed inside the inner tube 12, and a distal end opening 20 of the second lumen 14 opens on the distal end side of the distal end sealing portion 7 of the balloon portion 4. ing. As shown in FIGS. 1 and 2, the proximal end opening 22 of the inner tube 12 is opened to the outside through a through hole 21 in a tube wall located in the longitudinal direction of the outer tube 6. A periphery of the proximal end opening 22 of the inner tube 12;
The outer wall of the outer tube 6 is hermetically joined to the periphery of the through hole 21 in the tube wall by a heat sealing method. The shape of the proximal end opening 22 of the inner tube 12 is not particularly limited, and may take various shapes such as a circle and an ellipse. In the present embodiment, an elliptical shape obtained by cutting the opening end of the inner tube 12 obliquely. Shape. The second lumen 14 of the inner tube 12 is a guidewire insertion lumen through which a guidewire 42 shown in FIG. 4 for guiding the balloon catheter 2 into a body cavity is inserted. The guide wire 42 is made of, for example, stainless steel, copper,
It is composed of a single wire or a stranded wire such as a copper alloy, titanium, or a titanium alloy, and its outer diameter is not particularly limited, but is preferably 0.1 to 1 mm, more preferably 0.25 to 1
0.6 mm.

In this embodiment, the outer tube 6 includes a first outer tube member 6a having a circular cross section, and a second outer tube member 6b having a modified cross section joined to the proximal end of the first outer tube member 6a. And the proximal end opening 2 of the inner tube 12
2 is opened to the outside through a tube wall located in the longitudinal direction of the first outer tube member 6a. The axial length L2 of the first outer tube 6a is not particularly limited, but is preferably 100 to 400 mm, and more preferably 200 to 300 mm.

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

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

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

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

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

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

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

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

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

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

FIGS. 1, 2A-2C and 3
Is inserted over the entire length inside the fourth lumen 26 of the second outer tube member 6b, and the distal end thereof passes over the joint 9 with the first outer tube member 6a. It protrudes into the first lumen 10 of the first outer tube member 6a. The proximal end of the reinforcing rod 28 has a circular cross-section, tapers in the middle toward the distal end, and gradually has a cross-sectional shape at the distal end so as to have a flat cross-section. Has changed. As shown in FIGS. 1 and 4, the distal end portion 28a of the reinforcing rod 28 having a flat cross section slightly exceeds the proximal end opening portion 22 of the inner tube 12 (preferably about L3 = 1 to 10 cm). And the distal end 2a thereof is not fixed to the inner wall of the first outer tube member 6a.

In the present embodiment, the proximal end of the reinforcing rod 28 is inserted over the entire length into the fourth lumen 26 of the second outer tube member 6b, and a predetermined length L from the proximal end.
In the range of 5, it is fixed to the inner wall of the fourth lumen 26 by an adhesive. That is, in the present embodiment, the reinforcing rod 28 is not fixed to the inner wall of the fourth lumen 26 on the distal end side from the position of the predetermined length L4 from the tube joining portion 9 and the first outer tube member 6a It is not fixed to the inner wall of the first lumen 10. Predetermined length L4
And L5 are not particularly limited, but preferably L4 =
50 to 150 mm, preferably L5 = 1000 to 1
5000 mm.

The maximum outer diameter of the reinforcing rod 28 is the second outer diameter.
It is determined so that it can be inserted into the fourth lumen 26 of the outer tube member 6b, and is not particularly limited.
０．６0.6 mm. The reinforcing rod 28 is made of a metal material such as stainless steel, copper, copper alloy, titanium, and titanium alloy;
Alternatively, it is made of a synthetic resin such as polyimide, polyamide, or polyethylene terephthalate.

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

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

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

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

Next, a method for manufacturing the balloon catheter 2 according to the present embodiment will be described. First, the balloon part 4 shown in FIG. 4 is formed. The balloon portion 4 may be formed by a dipping method in which a mandrel for forming a balloon film is immersed in a solution, and may be formed by blow molding.

The thermoplastic resin in the solution used in the dipping method is not particularly limited, but examples thereof include a vinyl chloride resin, a urethane resin, an amide resin, an olefin resin, and an imide resin. it can. Among them, urethane resins having excellent flex fatigue resistance are preferable.

Suitable solvents for plasticizing the thermoplastic resin include tetrahydrofuran (THF) and methyl ethyl ketone (MEK) for vinyl chloride resins, and THF, MEK and MEK for urethane resins.
Dimethylacetamide, dimethylsulfoxide and the like are suitable. The solution solvent of the thermoplastic resin is a solution in which the above thermoplastic resin is dissolved by a solvent. For example, when polyurethane is used as the thermoplastic resin and THF is used as the solvent, a solution containing 5 to 20% by weight of the polyurethane is used. Preferably, it is used. The viscosity of this solvent solution is 100 to 10000 cp, preferably 1000 to 5 cp.
000 cp. At the distal end of the balloon portion 4 thus formed, as shown in FIG. 4, a tapered tapered portion 4c and a distal end sealing portion 7 tapering are integrally formed, and the balloon portion 4 is formed. As shown in FIG. 4, a tapered tapered portion 4b and a proximal end sealing portion 5 that are tapered are integrally formed at the proximal end.

Next, the first joining portion 5a of the proximal end sealing portion 5 of the balloon portion 4 is joined to the outer periphery of the distal end of the first outer tube member 6a. For this joining, a mandrel is inserted into the distal end of the first outer tube member 6a, and then the first joining of the proximal end sealing portion 5 of the balloon portion 4 to the outer periphery of the distal end of the member 6a. The part 5a is overlapped. Then, the outer periphery of the first joint portion 5a is covered with a heat-resistant film, and the heat-resistant film is heated with a mold or the like, so that the first joint portion 5a is connected to the first outer tube member 6a.
Heat fused to the distal end. The heating temperature is not particularly limited, but is preferably 100 to 300 ° C, particularly preferably 150 to 250 ° C.

As the heat-resistant film, for example, a fluororesin tube is used, and its axial length is preferably longer than the first joint portion 5a, for example, about 20 m.
m. At one end in the axial direction of the tube, a length of about 3m
A notch of about m may be formed. This is because the heat-resistant film can be easily removed after the heat-sealing.

Thereafter, as shown in FIG. 4, a through hole 21 is formed in the tube wall at a predetermined position in the axial direction of the first outer tube member 6a so that the inner tube 12 can pass therethrough.

Next, the inner tube 12 on which the contrast ring 15 is mounted is prepared. Contrast ring 1 on inner tube 12
In the present embodiment, first, as shown in FIG. 7, at a position separated from the distal end of the inner tube 12 by a predetermined distance Lt with the finger or the like via the non-slip sheet 50 in this embodiment,
The distal end of the inner tube 12 is pulled with a plier or the like in the direction of the arrow. As a result, the outer diameter of the inner tube 12 in the range of the predetermined distance Lt becomes slightly smaller. Note that a rubber sheet is used as the non-slip sheet 50. The predetermined distance Lt is, for example, 3 to 10 mm.

Next, the portion sandwiched by the pliers or the like is removed with a razor or the like, and a mandrel for shape restoration is inserted into the distal end of the inner tube 12, and the flattened portion of the inner tube is returned to a circular cross section. Thereafter, the shape restoring mandrel is pulled out, and instead, the drawing mandrel 54 shown in FIG. 8 is inserted into the distal end of the inner tube 12.
In this state, the distal end of the inner tube 12 is passed through the circular hole of the drawing die 52,
The distal end of the inner tube 12 is drawn. Die 5
2 is heated, for example, to 40-80 ° C.

As a result, the outer diameter of the inner tube 12 is reduced from the original outer diameter D1, and the reduced diameter portion 58 having the outer diameter D2 is formed. Note that the inner diameter of the reduced diameter portion 58 of the inner tube 12 maintains the original inner diameter of the inner tube 12 for the mandrel 54. The outer diameter D2 of the reduced diameter portion 58 shown in FIG.
Is D2 / D1 = 0.8 to .0 with respect to the original outer diameter D1.
It is preferably 95. The thickness T2 of the reduced diameter portion 58 is different from the original thickness T1 of the inner tube 12 shown in FIG.
It is preferable that T2 / T1 has a relationship of 0.6 to 0.9.

The outer diameter D 2 of the reduced diameter portion 58 is preferably equal to or less than the inner diameter of the contrast ring 15. As shown in FIG. 9, the reduced diameter portion 5 on which the mandrel 54 is mounted
This is because the contrast ring 15 is easily attached to the outer periphery of the reference numeral 8. In the present embodiment, one of the contrast rings 15 disposed on the proximal end side is connected to the reduced diameter portion 5 from the original outer diameter of the inner tube 12.
8 and the contrast ring 15
The other contrast ring 15 is attached to a position at a predetermined distance Ls shown in FIG.

In this state, the reduced diameter portion 58 of the inner tube 12 is heated at a predetermined temperature. It is preferable that the predetermined temperature is in the range of about 5 to 20 ° C., preferably about 7 to 15 ° C., lower than the melting point of the synthetic resin forming the inner tube 12. For example, when the inner tube 12 is made of polyethylene, the heating temperature is preferably 120 ± 5 ° C.

As a result of heating the reduced diameter portion 58 of the inner tube 12, as shown in FIG. 6, the outer diameter of the reduced diameter portion 58 is restored, and the contrast ring 15 can be fixed at a predetermined position of the inner tube 12. . Outer diameter D4 of inner tube 12 after restoration
Is substantially the same as the original outer diameter D1 of the inner tube 12. For example, D4 / D1 is in the range of 0.9 to 1,
The reduced diameter portion 58 can be restored.

The ratio D4 / D5 of the outer diameter D4 of the inner tube after restoration to the outer diameter D5 of the contrast ring 15 is preferably 0.7 to 1. The ratio D4 / D of the outer diameter D4 of the inner tube 12 after restoration to the inner diameter D3 of the contrast ring 15
3 is preferably 1 to 1.2.

After manufacturing the inner tube 12 having the pair of contrast rings 15 mounted at predetermined positions on the distal end of the inner tube 12 as described above, the inner tube 1 is manufactured as follows.
2 is mounted inside the balloon section 4 shown in FIG.

First, the lumen of the inner tube 12 is integrated through a wire-like mandrel. The inner tube 12 with the integrated mandrel is passed through the through-hole 21 into the inner lumen of the first outer tube member 6a.
2 protrudes from the distal end sealing portion 7 of the balloon portion 4, and each imaging ring 15 is connected to the intersection 4ab of the balloon portion 4.
And 4ac. Before and after that, the heat sealing tube is positioned on the outer periphery of the first outer tube member 6a.

Thereafter, a heat sealing mandrel is inserted into the inside from the proximal end of the first outer tube member 6a, and the tip of the mandrel is positioned near the through hole 21. The outer tube 6a is prevented from being crushed.
The base end of the mandrel has an outer diameter substantially equal to or less than the inner diameter of the first outer tube member 6 a, and an axial recess is formed at the distal end thereof to receive the outer circumference of the inner tube 12. It is. Next, the heat-sealing tube is
The tube is moved axially around the outer periphery of the outer tube member 6a so that the heat-sealing tube has the outer periphery of the first outer tube 6a near the through-hole 21 and the inner tube 1 that protrudes from the through-hole 21.
2 and the outside. Then, using a heat-sealing mold, heating is performed by pressing from the outside of the heat-sealing tube, so that the edge of the through-hole 21 and the inner tube 12 are heated.
The outer tube wall is heat-sealed. The heating temperature is not particularly limited, but is preferably 100 to 300 ° C, particularly preferably 150 to 250 ° C.

Thereafter, the mandrel is taken out and the heat sealing tube is removed. Thereafter, the outer tube wall of the inner tube 12 and the through-hole 21 which are heat-sealed in the heat-sealing process are formed.
The unnecessary portion of the inner tube 12 located outside from the heat-sealed portion is removed by cutting with a cutter or the like, leaving a heat-sealed portion with the inner edge of the inner tube. As a result, the proximal end opening 22 of the inner tube 12 is formed to open outside the tube wall of the first outer tube member 6a. The proximal end opening 22 has a substantially elliptical shape in this example.

Before or after these steps or simultaneously, the distal end of the inner tube 12 is heat-sealed to the distal end sealing portion 7 of the balloon 4 by the same heat sealing method. It is processed so that the tip taper portion 7a is formed. Details are shown below.

First, as shown in FIG.
2 is passed through the distal end sealing portion 7 of the balloon portion 4 and the mandrel 40 is inserted into the inner tube 12 from its distal end. Then, the second tube 12
The outer periphery of the distal end sealing portion 7 of the balloon portion 4 is covered with a heat-resistant film 41 at a position corresponding to the joint portion 12 a, and the heat-resistant film 41 is heated by a mold 43. As a result, the distal end sealing portion 7 of the balloon portion 4 is thermally fused to the outer periphery of the inner tube 12 at the fusion portion 44 corresponding to the axial length of the heat resistant film 41. At the time of heat fusion, the balloon 4 is wound around the inner tube 12 and folded, and its outer periphery is protected by a protective tube or the like. As the protective tube, a heat-resistant fluororesin tube is used.

The heating temperature at the time of heat fusion is not particularly limited, but is preferably 100 to 300 ° C., particularly preferably 150 to 250 ° C., similar to heat fusion at the proximal end sealing portion 5 of the balloon portion 4. ° C. In addition, heat-resistant film 4
As 1, for example, a fluororesin tube is used,
A cut having a length of about 3 mm may be formed at one end in the axial direction of the tube. After heat fusion, heat-resistant film 41
It is for making it easy to remove.

After the distal end sealing portion 7 is thermally fused to the outer periphery of the inner tube 12 at the fusion portion 44, the mold 43 is removed, the heat-resistant film 41 is removed, and the mandrel 40 is removed. The unnecessary portion 7b on the distal end side of the lower end sealing portion 7 is removed. When the unnecessary portion 7b is removed, an unfused portion 46 is formed at the distal end side of the fusion portion 44 in the distal end sealing portion 7, so that the unnecessary portion 7b can be easily removed with a cutter or the like. Then, the smooth tapered portion 7
In order to form a, the tip taper surface 7a of the distal end sealing portion 7 is pressed against, for example, a rotating surface of a polishing rotary disk to perform polishing. Thereafter, as shown in FIG. 5, the distal end of the inner tube 12 is cut into a predetermined length Lf, and the cut surface is chamfered to form a tapered surface 12c.

Thereafter, the distal end of the second outer tube portion 6b is joined to the proximal end of the first outer tube member 6a. At the time of the joining, first, a heat sealing tube is put on the outer periphery of the second outer tube member 6b,
a into the lumen at the proximal end of the second outer tube member 6b.
Press the distal end of the Then, the second outer tube member 6
A mandrel is inserted along the axial direction into the inside of the third lumen 24 of b, and its tip is projected to the inside of the first outer tube member 6a. Before or after or at the same time, a reinforcing rod 28 is inserted along the axial direction into the fourth lumen 26 of the second outer tube member 6b, and the distal end thereof is formed on the outer periphery of the first outer tube member 6a. It is positioned below the end opening 22.

Thereafter, the heat-sealing tube is moved in the axial direction, and the heat-sealing tube is used to connect the joint 9 between the first outer tube member 6a and the second outer tube member 6b.
And heat-sealing is performed using a mold under the same heat sealing conditions as those described above.

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

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

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

Next, only the guide wire for the guide catheter is withdrawn, a guide wire for a balloon catheter thinner than that is inserted along the guide catheter, and the distal end thereof is inserted until it passes through the stenosis.

Thereafter, the distal end of the guidewire is inserted into the distal open end 20 of the balloon catheter 2 shown in FIG. 1, passed through the first lumen 14 and withdrawn from the proximal end opening 22. Then, the balloon catheter 2 is passed through the guide catheter along the guide wire 42 in a state where the balloon portion 4 is folded. Then, as shown in FIG. 11, the balloon portion 4 of the balloon catheter 2 is inserted into the blood vessel 34 up to just before the stenosis portion 36.

Thereafter, the folded balloon portion 4 of the balloon catheter 2 is inserted between the stenotic portions along a guide wire. Next, while observing the position of the balloon portion 4 with an X-ray fluoroscope, the balloon portion 4 is accurately positioned at the center of the stenosis. By inflating the balloon portion 4 at that position, the stenotic portion of the blood vessel can be widened and good treatment can be performed. The balloon section 4 is inflated by injecting a liquid into the balloon section 4 from the port of the connector 8 shown in FIG. 1 through the third lumen 24 and the first lumen 10.

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

In the balloon catheter 2 according to the present embodiment, only the distal end of the balloon catheter 2 adopts a so-called coaxial catheter tube structure composed of the outer tube 6 and the inner tube 12. The lumen 14 is used as a guide wire insertion lumen. For this reason, a conventional balloon catheter having a so-called double-lumen catheter tube (Japanese Unexamined Patent Publication No.
The balloon catheter 2 according to the present embodiment is described in comparison with Japanese Patent Application Laid-Open Nos. 3-288167 and 2-307479.
Then, the outer diameter of the first outer tube member 6a can be easily reduced. Further, in the balloon catheter 2 according to the present embodiment, the proximal end opening 22 of the inner tube 12 serving as the proximal end side outlet of the guide wire penetrates the tube wall located in the longitudinal direction of the outer tube 6. In the opening 22, the inner tube 12 and the outer tube 6 have a double structure, and are hardly kinked.

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

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

Further, in the present embodiment, since the distal end portion 28a of the reinforcing rod 28 is not fixed to the inner wall of the first outer tube member 6a, the balloon catheter 2 has a large number of bifurcated portions like a coronary artery. Even when inserted into a thin blood vessel, the distal end of the first outer tube member 6a is flexibly deformed corresponding to the bent portion of the blood vessel. This is because the distal end 28a of the reinforcing rod 28 is not fixed to the inner wall of the first outer tube member 6a.
It is considered that the distal end of “a” can be freely deformed without being restricted by the reinforcing rod 28.

Further, in this embodiment, the balloon section 4
Has a first joined portion 5a that is overlapped and joined to the distal end of the outer tube portion 6, and a first non-joined portion 5b that does not overlap. The first non-joining portion 5b in the proximal end sealing portion 5 of the balloon portion 4 is a portion that hardly contributes to a therapeutic effect by expansion of the balloon portion 4, but by providing such a portion, the distal end of the balloon catheter 2 can be formed. The flexibility at the ends is improved. This is because the first non-joined portion 5b is a part of the balloon portion 4 and is more flexible than the outer tube portion 6.

Therefore, even when the balloon catheter 2 of the present embodiment is inserted into a thin blood vessel having many branches such as a coronary artery, the distal end of the balloon catheter 2 is flexible in correspondence with the bent part of the blood vessel. Deform to. That is, in the balloon catheter 2 of the present embodiment, the insertion characteristics and the pushing characteristics of the balloon catheter 2 are improved.

In this embodiment, the distal end sealing portion 7 of the balloon portion 4 joined to the distal end of the inner tube 12 has a smaller outer diameter toward the outer periphery of the distal end of the inner tube 12. Is formed. In addition, a second non-joining portion 12b to which the distal end sealing portion 7 of the balloon portion 4 is not joined is formed on the outer periphery of the distal end portion of the inner tube 12.

For this reason, as shown in FIG. 11, the outer diameter of the distal end of the balloon catheter 2 becomes equal to the outer diameter of the inner tube 12, particularly when the degree of stenosis is severe or when the stenosis of the winding blood vessel 34 is increased. The distal end of the balloon catheter 2 can be easily inserted into the portion 36 as well. Therefore, the insertion characteristics of the balloon catheter 2 are improved.

In particular, in the present embodiment, the outer diameter of the inner tube 12 in a predetermined length range including the position where the contrast ring 15 is mounted is forcibly reduced, and the outer diameter is equal to or less than the inner diameter of the contrast ring 15. Since the reduced diameter portion 58 having the shape is formed, the operation of attaching the contrast ring 15 to the reduced diameter portion 58 of the inner tube 12 is easy. The imaging ring 15 is attached to the reduced diameter portion 58, and thereafter, the outer diameter of the reduced diameter portion 58 is restored to near the original outer diameter by heating. Therefore, as shown in FIG. 6, the contrast ring 15 has a structure embedded in the outer periphery of the inner tube 12, and is fixed at a predetermined position.

The balloon catheter 2 manufactured as described above has a structure in which the contrast ring 15 is embedded in the outer periphery of the inner tube 12. At the position where the contrast ring 15 is mounted, the contrast ring 15 is excessively moved from the outer periphery of the inner tube 12. No longer protrude. As a result, it is possible to reduce the outer diameter of the balloon portion 4 in a state in which the balloon portion 4 is folded on the outer periphery of the inner tube 12, and particularly when the degree of stenosis is severe or for a stenotic portion of a meandering blood vessel.
The distal end of the balloon catheter 2 can be easily inserted. Therefore, the insertion characteristics of the balloon catheter 2 are improved.

In the method for manufacturing a balloon catheter according to the present embodiment, the balloon catheter is relatively
It can be easily manufactured, the joint strength between the imaging ring 15 and the inner tube 12 is sufficient, and in the manufacture thereof, defects such as an extremely thin inner tube hardly occur. In addition, when the contrast ring 15 and the inner tube 12 are joined, an adhesive or the like is not necessarily required.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, in the above-described embodiment, the outer tube 6 is configured by the first outer tube member 6a and the second outer tube member 6b, but in the present invention, the outer tube 6 is configured by a single tube that is continuous in the axial direction. It is also possible. Further, the use of the balloon catheter according to the present invention,
It is not limited to the use described above.

Further, the present invention is not limited to a balloon catheter, but includes a metal ring (such as a contrast ring 1 in the above embodiment) used as an electrode or a sensor on the outer periphery of a tube.
5 (corresponding to No. 5) can be applied to a medical device to which the device is attached. An example of a medical device in which an electrode is attached to the outer periphery of a tube is an electrode catheter.

[0104]

As described above, according to the present invention, it is possible to reduce the outer diameter of the tube portion to which the metal ring is attached as much as possible, and to provide a medical device excellent in insertability into a body cavity and a medical device. In addition, it is possible to provide a method for manufacturing a medical device that can be manufactured very easily without causing a defect in the tube.

Further, according to the present invention, the distal end of the balloon catheter can be easily inserted even in a case where the degree of stenosis is severe or in a narrowed portion of a tortuous blood vessel. It is possible to provide a balloon catheter having excellent characteristics and a method of manufacturing a balloon catheter that can extremely easily manufacture the balloon catheter without causing a defect in the inner tube.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a balloon catheter according to one embodiment of the present invention.

2A is a sectional view taken along the line IIB-IIB shown in FIG. 1, FIG. 2B is a sectional view taken along the line IIB-IIB shown in FIG. 1,
FIG. 2C is a sectional view taken along the line IIC-IIC shown in FIG.
FIG. 2D is a sectional view taken along line IID-IID shown in FIG. 1.

FIG. 3 is a side view of the reinforcing rod shown in FIG.

FIG. 4 is a longitudinal sectional view of a main part of the balloon catheter shown in FIG.

FIG. 5 is a sectional view of a main part showing details of a distal end of the balloon catheter shown in FIG. 4;

FIG. 6 is a cross-sectional view of an essential part showing a structure for attaching a contrast ring to an inner tube located in a balloon portion.

FIG. 7 is a main part side view showing a method of attaching a contrast ring to an inner tube.

FIG. 8 is a cross-sectional view of a main part showing a continuation of FIG. 7;

FIG. 9 is a cross-sectional view of a main part showing a step continued from FIG.

FIG. 10 is a fragmentary cross-sectional view showing a step of joining a distal end sealing portion of the balloon portion and a distal end portion of the inner tube.

FIG. 11 is a sectional view of a main part showing an example of use of the balloon catheter shown in FIG.

[Explanation of symbols]

 2 ... Balloon catheter 4 ... Balloon part 4a ... Cylindrical part 4b, 4c ... Tapered reduced diameter part 5 ... Proximal end sealing part 5a ... First joining part 5b ... First non-joining part 7 ... Distal end sealing Part 7a ... Tip taper part 7b ... Unnecessary part 6 ... Outer tube 6a ... First outer tube member 6b ... Second outer tube member 8 ... Connector 10 ... First lumen 12 ... Inner tube 12a ... Second joint part 12b ... Second Non-joined part 14 ... Second lumen 15 ... Contrast ring 20 ... Distal end opening 21 ... Through hole 22 ... Proximal end opening 24 ... Third lumen 26 ... Fourth lumen 28 ... Reinforcement rod 44 ... Fusion part 58 … Reduced diameter part

Claims (14)

[Claims] An outer diameter of a synthetic resin tube in a predetermined length range including a position where a metal ring is mounted is forcibly reduced, and a reduced diameter portion having an outer diameter equal to or less than the inner diameter of the metal ring is provided. After formation, a metal ring is attached to the reduced diameter portion, and thereafter, the outer diameter of the reduced diameter portion is restored by heating, and the metal ring is fixed to a predetermined position of the tube. And medical instruments. 2. The medical device according to claim 1, wherein the ratio of the outer diameter of the tube after restoration to the outer diameter of the metal ring is 0.7 to 1. 3. The medical device according to claim 1, wherein a ratio of an outer diameter of the tube after restoration to an inner diameter of the metal ring is 1 to 1.2. 4. An outer tube having at least one balloon inflation lumen formed along a longitudinal direction thereof, and a proximal end sealing portion of a balloon portion joined to a distal end of the outer tube. A balloon portion having an interior communicating with the expansion lumen, and a distal end sealing portion of the balloon portion joined to a distal end portion of the inner tube so as to form a sealed expansion space inside the balloon portion. An inner tube extending in the axial direction inside the balloon portion and inside the balloon expansion lumen of the outer tube; and at least one attached to an outer peripheral portion of the inner tube located inside the balloon portion. A contrast ring, wherein the outer diameter of the inner tube in a predetermined length range including a position where the contrast ring is attached is forcibly reduced in diameter, and the contrast ring is After forming a reduced diameter portion having an outer diameter equal to or less than the inner diameter of the, the contrast ring is attached to the reduced diameter portion, and then, by heating, the outer diameter of the reduced diameter portion is restored, the contrast ring Is fixed to a predetermined position of the inner tube. 5. The balloon catheter according to claim 4, wherein a ratio of an outer diameter of the inner tube after restoration to an outer diameter of the contrast ring is 0.7 to 1. 6. The balloon catheter according to claim 4, wherein a ratio of an outer diameter of the inner tube after restoration to an inner diameter of the contrast ring is 1 to 1.2. 7. A reduced diameter portion having an outer diameter equal to or less than the inner diameter of the metal ring is forcibly reduced in outer diameter of a synthetic resin tube in a predetermined length range including a position where the metal ring is mounted. After forming, a metal ring is attached to the reduced diameter portion, and thereafter, by heating, the outer diameter of the reduced diameter portion is restored, and the metal ring is fixed to a predetermined position of the tube. Manufacturing method of medical equipment. 8. The medical device according to claim 7, wherein a heating temperature of the reduced diameter portion is in a range of about 5 to 20 ° C. lower than a melting point of the synthetic resin forming the tube. Method. 9. The method for manufacturing a medical device according to claim 7, wherein the reduced diameter portion is formed by pulling a distal end of the tube in an axial direction. 10. The method for manufacturing a medical device according to claim 7, wherein the reduced diameter portion is formed in a state where a mandrel is inserted into a lumen of the tube. 11. An outer tube having at least one balloon inflation lumen formed along a longitudinal direction thereof, and a proximal end sealing portion of a balloon portion joined to a distal end of the outer tube. A balloon portion that communicates with the expansion lumen, and a distal end sealing portion of the balloon portion is joined to a distal end portion of the inner tube so as to form a sealed expansion space inside the balloon portion. An inner tube extending axially inside the balloon portion and inside the balloon expansion lumen of the outer tube; and at least one of the inner tubes attached to the outer peripheral portion of the inner tube located inside the balloon portion. Contrast ring, and a method for manufacturing a balloon catheter having, wherein the outer diameter of the inner tube of a predetermined length range including the position where the contrast ring is attached is forcibly reduced, After forming a reduced diameter portion having an outer diameter equal to or less than the inner diameter of the contrast ring, at least one contrast ring is attached to the reduced diameter portion, and then, by heating, the outer diameter of the reduced diameter portion is reduced. Restoring and fixing the contrast ring to a predetermined position of the inner tube. 12. The balloon catheter according to claim 11, wherein a heating temperature of the reduced diameter portion is in a range of about 5 to 20 ° C. lower than a melting point of a synthetic resin forming the inner tube. Production method. 13. The method according to claim 11, wherein the reduced diameter portion is formed by pulling a distal end of the inner tube in an axial direction. 14. The method according to claim 11, wherein the reduced diameter portion is formed in a state where a mandrel is inserted into the lumen of the inner tube.