JP2010220760A - Balloon catheter and manufacturing method thereof - Google Patents

Abstract

Disclosed is a balloon catheter that has a sufficient diameter and a sufficient pressure resistance at a guide wire insertion port, and has a good operability and a manufacturing method thereof.
In the balloon catheter 1, the cross-sectional shape of the balloon-expanding lumen 23 is a crescent shape at the wire port fusion portion 50. Thereby, while ensuring sufficient cross-sectional area to the balloon expansion lumen 23 and the guide wire lumen 43, the surrounding side wall can be made thick enough.
[Selection] Figure 1

Description

  The present invention relates to a balloon catheter used as, for example, a balloon catheter for vasodilation, and more particularly to a so-called monorail type balloon catheter.

  In order to treat the stenosis in the blood vessel, it is inserted into the blood vessel and the balloon is inflated to expand the stenosis, so that the so-called PTCA balloon catheter for improving blood flow at the peripheral side of the stenosis is over. There are the wire type balloon catheter and the monorail type balloon catheter. In any of these types of balloon catheters, the guide wire is first passed through the stenosis part in the blood vessel, and then the balloon catheter is fed along the guide wire to the stenosis part, and the balloon part is inflated to expand the stenosis part. To expand. At that time, the stenosis part needs to be expanded step by step so as not to damage the blood vessel. At first, a balloon catheter having a balloon part with a small outer diameter is inserted along the guide wire, and the outer diameter is sequentially increased. Replace the balloon catheter with a balloon part.

  In the over-the-wire type balloon catheter, a guide wire lumen is formed over the entire length of the catheter tube, the guide wire is inserted along the lumen, and the balloon portion is guided to the stenosis portion along the guide wire. I will guide you. Then, after performing blood vessel dilation using a balloon catheter having a balloon portion having a small outer diameter, the balloon catheter is replaced with a balloon catheter having a balloon portion having a larger outer diameter. At that time, since the balloon catheter is pulled out along the guide wire, the proximal end of the guide wire needs to extend outside the body more than the entire length of the catheter tube. Otherwise, the balloon catheter cannot be replaced while leaving the distal end of the guidewire in the stenosis.

On the other hand, in the monorail type balloon catheter, an opening as a guide wire insertion opening is formed in the middle of the catheter tube, and the guide wire is inserted from the opening to the distal end of the balloon portion through the guide wire insertion lumen. Yes. Therefore, in this type of balloon catheter, the length of the guide wire extending outside the body for replacement of the balloon catheter may be slightly longer than the length corresponding to the length from the opening to the distal end of the balloon. Compared with other systems, it can be shortened and has excellent operability.
As a monorail type balloon catheter, for example, those disclosed in Patent Document 1 or Patent Document 2 are known.

JP 2000-217923 A JP 2004-350901 A

This type of balloon catheter is required to have a smaller diameter in order to widen the treatment target and improve the operability. In the conventional monorail type balloon catheter, the outer diameter of the catheter is required. When the width of the inner tube is reduced, there is a problem in that it is impossible to sufficiently secure the pressure-resistant strength at the portion where the guide wire insertion port through which the inner tube penetrates the side wall of the outer tube is formed.
On the other hand, when the thickness of the tube side wall of this portion is increased in order to improve the strength of the portion where the guide wire insertion opening is formed, the cross-sectional areas of the balloon expansion lumen and the guide wire lumen are reduced when the outer diameter is maintained. There is a problem that the operability of the balloon catheter is deteriorated.

  Therefore, in order to ensure both strength and the cross-sectional areas of the balloon dilating lumen and the guide wire lumen, the balloon catheter must be thickened after all, and there is a limit to reducing the diameter of the balloon catheter. In other words, conventionally, a sufficiently thin balloon catheter cannot be manufactured, and there is a demand for a balloon catheter that is small in diameter, good in operability, and safe.

  The present invention has been made in view of such problems, and the object thereof is a balloon that has a small diameter but has sufficient pressure-resistant strength at the guide wire insertion port, and has good operability and safety. It is providing the catheter and its manufacturing method.

  In order to solve the above problems, a balloon catheter according to the present invention includes an outer tube having a balloon dilating lumen formed along the axial direction and a guide wire lumen formed therein, and the outer tube. A balloon portion having an inner tube extending in the axial direction inside the balloon expanding lumen, and an expansion space communicating with the balloon expanding lumen, the distal portion of the outer tube having the balloon portion A balloon portion in which a proximal end portion is joined and a distal end portion of the balloon portion is joined to a distal end portion of the inner tube, and a proximal end portion of the inner tube is in the longitudinal direction of the outer tube A balloon catheter having a wire port fused portion formed with a guide wire insertion opening that penetrates the tube wall and opens to the outside. The outer diameter of the outer tube in the wire port fusion part is 0.86 mm or less, and the inner tube forming the guide wire lumen in the wire port fusion part on the side where the outer tube is fused. The wall thickness is 0.015 mm or more.

  The inner tube disposed inside the balloon-expanding lumen is bent from the state of being coaxially extended with the outer tube in the vicinity of the guide wire insertion hole, and the outer tube on the side where the guide wire insertion hole is formed. It extends so as to be unevenly distributed on the side wall (tube wall) side, contacts the inner periphery of the side wall of the outer tube in the vicinity of the guide wire insertion hole, and opens at the proximal end through the region fused with the outer tube. Is exposed to the outer surface of the outer tube as a guide wire insertion hole. Conventionally, the inner tube on the side where the inner tube and the outer tube are fused is thinned, for example, when the overall outer diameter is small, such as the pressure resistance of this portion. The strength was not enough. In the balloon catheter according to the present invention, even when the outer diameter of the outer tube is as small as 0.86 mm or less, at least the portion where the inner tube and the outer tube are fused is fused. The inner tube is formed to have a wall thickness of 0.015 mm or more.

  As a preferable specific example of the balloon catheter of the present invention, the outer tube, that is, the outer diameter of the balloon catheter is 0.80 to 0.86 mm, and the outer tube of the inner tube of the wire port fusion portion at that time is The thickness of the fused side wall is 0.015 to 0.055 mm.

Preferably, the balloon catheter of the present invention is characterized in that a cross-sectional shape of the balloon expansion lumen in the wire port fusion part is formed in a substantially crescent shape.
Also preferably, in the balloon catheter of the present invention, in the wire port fusion part, the cross-sectional area of the balloon expansion lumen is 24 to 37% of the total catheter cross-sectional area of the wire port fusion part. Features.
Also preferably, in the balloon catheter of the present invention, in the wire port fusion portion, a cross-sectional area ratio between the balloon dilating lumen and the guide wire lumen, (cross-sectional area of the balloon dilating lumen) / (guide wire lumen) ) Is 1.05 to 1.41.

Also preferably, in the balloon catheter of the present invention, the thickness of the side wall of the inner tube forming the guide wire lumen in the wire port fused portion opposite to the side fused to the outer tube is thick. It is formed to be 0.05 mm or more.
Also preferably, the balloon catheter of the present invention is such that the thickness of the side wall of the outer tube forming the balloon dilating lumen in the wire port fused portion on the side opposite to the side fused with the inner tube. Is formed to be 0.06 mm or more.

  The balloon catheter manufacturing method according to the present invention includes a step of inserting the inner tube member into the lumen of the distal outer tube member, and one end side of which is substantially the same as the inner side of the lumen of the proximal outer tube member. A notch mandrel formed in a circular cross section with a diameter and a notch portion having a substantially crescent cross section on the other end side, and the notch portion of the notch mandrel is connected to the outer peripheral surface of the inner tube member. And inserted into the lumen of the distal outer tube member from the proximal end of the distal outer tube member so as to enter the gap between the inner peripheral surface of the distal outer tube member and the notched mandrel Bending the inner tube member in the vicinity of the proximal end of the distal outer tube member along the proximal end of the notch, and the distal end of the proximal outer tube member at the distal end. Cutout Insert the end of the side where the cross-section of the dodrel is formed into a circular shape, push the proximal outer tube member toward the distal outer tube member, and An overlapping portion is formed between the end portion and the distal end portion of the proximal outer tube member; and a peripheral edge of the proximal end portion of the distal outer tube member and a distal end portion of the proximal outer tube member Forming an opening surrounded by a peripheral edge of the upper end, exposing the proximal end of the inner tube member outwardly from the formed opening, the proximal end of the inner tube member, and the Fusing and integrating the peripheral edge of the opening and the overlapping portion of the distal outer tube member and the proximal outer tube member.

  According to the present invention, it is possible to provide a balloon catheter that is sufficiently thin and has sufficient pressure-resistant strength at the guide wire insertion port, has good operability, and a safe manufacturing method thereof.

FIG. 1 is a diagram showing a configuration of a balloon catheter according to an embodiment of the present invention, (A) is an overall view of the balloon catheter, (B) is a cross-sectional view at a position B in (A), (C) is sectional drawing in the location of C of (A), (D) is sectional drawing in the location of D of (A). FIG. 2 is a diagram showing the configuration of the wire port fusion part of the balloon catheter shown in FIG. 1, and is an enlarged view of the axial section of the region A in FIG. 1 (A). FIG. 3 is an enlarged view of a radial sectional view of the wire port fusion part of the balloon catheter shown in FIG. 4A to 4C are views for explaining a method for manufacturing the balloon catheter shown in FIG. 5 (A) and 5 (B) are diagrams for explaining the method for manufacturing the balloon catheter shown in FIG. 1 following FIG. 4, and FIGS. 5 (C) and 5 (D) are views of FIGS. It is a figure explaining the example of the other manufacturing method corresponding to the manufacturing method shown to (B). FIG. 6 is a diagram for explaining a method of manufacturing the balloon catheter shown in FIG. 1 following FIG. FIGS. 7A to 7C are views for explaining a method of manufacturing the balloon catheter shown in FIG. 1 following FIG. FIG. 8 is a diagram for explaining a method of manufacturing the balloon catheter shown in FIG. 1 following FIG. FIGS. 9A to 9C are diagrams showing another embodiment of the balloon catheter according to the present invention. FIG. 10 is a diagram showing the relationship between the outer diameter and the body pressure in the balloon catheter. FIG. 11 is a diagram showing the relationship between the outer diameter and the pressure strength of the balloon catheter.

A balloon catheter and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the present invention will be described by exemplifying a PTCA balloon catheter (hereinafter simply referred to as a balloon catheter) used for dilating a stenosis occurring in a coronary artery in percutaneous coronary angioplasty (PTCA). To do.

  As shown in FIG. 1, the balloon catheter 1 of this embodiment is a so-called monorail type balloon catheter, and includes a balloon unit 10, an outer tube (outer shaft) 20 as a catheter tube, an inner tube (guide wire shaft) 40, and A connector 60 is provided.

  The balloon part 10 is a cylindrical film body having both ends reduced in diameter. The balloon portion 10 is guided to the stenosis portion of the blood vessel in a state where the balloon portion 10 is folded and has a small outer diameter, and is expanded at the stenosis portion, thereby expanding the stenosis portion of the blood vessel.

The proximal end portion 11 of the balloon portion 10 is joined to the outer periphery of the distal end portion 22 of the outer tube 20 by means such as heat fusion or adhesion, and the balloon expansion lumen 23 of the outer tube 20 is connected to the balloon portion 10. It communicates with the internal expansion space 13. The distal end portion 12 of the balloon portion 10 is joined to the outer periphery of the distal end portion 42 of the inner tube 40 by means such as heat fusion or adhesion. With such a configuration, the internal expansion space 13 of the balloon unit 10 is configured to be sealed with respect to the outside except for the balloon expansion lumen 23.
The balloon unit 10 is not particularly limited as long as it is cylindrical, and may be cylindrical or polygonal.

  Although the film thickness of the cylindrical film | membrane body which comprises the balloon part 10 is not specifically limited, Usually, it is about 15-300 micrometers, Preferably it is about 30-150 micrometers. The outer diameter of the balloon portion 10 when it is expanded is determined by conditions such as the inner diameter of the blood vessel, but is usually about 1.25 to 10.0 mm, preferably about 1.25 to 7 mm. The axial length of the balloon part 10 is also determined by conditions such as the size of the intravascular stenosis part, and is usually about 5 to 50 mm, preferably about 9 to 40 mm. In addition, the balloon part 10 before expansion is folded around the inner tube 40 and wound so that the outer diameter is as small as possible.

  The material constituting the balloon portion 10 is preferably a material having a certain degree of flexibility. For example, a copolymer of ethylene such as polyethylene, polyethylene terephthalate, polypropylene, ethylene-propylene copolymer and other α-olefins. Polymer, 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, preferably Are polyethylene, polyethylene terephthalate, and polyamide.

  The outer tube 20 is a tubular body in which a balloon expanding lumen 23 is formed along the inner central axis. The balloon-expanding lumen 23 feeds fluid into the internal expansion space 13 of the balloon unit 10 to expand the balloon unit 10 or draws fluid from the internal expansion space 13 of the balloon unit 10 to contract the balloon unit 10. Is the lumen. The proximal end 21 of the outer tube 20 is joined to the connector 60, and the distal end 22 of the outer tube 20 is joined to the proximal end 11 of the balloon part 10. As a result, the inside of the connector 60, the balloon expansion lumen 23, and the internal expansion space 13 of the balloon portion 10 communicate with each other.

As shown in FIGS. 1 (B) to (D), the outer tube 20 is composed of tube members having substantially the same outer diameter and inner diameter with a substantially circular cross section over the entire length.
Although the length of the outer tube 2 may be arbitrary length, it is about 500-2000 mm, for example, Preferably it is about 1000-1500 mm. The outer diameter of the outer tube 20 is not particularly limited, but in the balloon catheter 1 of the present embodiment, the outer diameter is as small as 0.86 mm or less, preferably 0.80 to 0.86 mm. Moreover, although the internal diameter of the outer tube 20 is not specifically limited, For example, it is 0.73 mm or less, Preferably it is 0.68-0.71 mm. Moreover, although the thickness of the outer tube 20 is not specifically limited, For example, it is 0.06-0.09 mm, Preferably it is 0.065-0.085 mm.

  The material constituting the outer tube 20 may be the same material as that of the balloon part 10, and is preferably composed of a flexible polymer material. For example, polyethylene, polyethylene terephthalate, polypropylene, ethylene-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. can be used, preferably Consists of polyethylene, polyamide, and polyimide.

The inner tube 40 is a tubular body in which a guide wire 70 for guiding the balloon catheter 1 into the body cavity is inserted (see FIG. 2), and a guide wire lumen 43 is formed along the inner central axis. It extends inside the lumen for balloon expansion 23 on the distal end 22 side of the inner expansion space 13 and the outer tube 20.
The distal end portion 42 of the inner tube 40 is located further on the distal side than the distal end portion 22 of the outer tube 20, and opens at the distal end portion 12 of the balloon portion 10.

The proximal end portion 41 of the inner tube 40 penetrates the side wall (wire port fused portion tube wall 26) in the wire port fused portion 50 in the longitudinal direction of the outer tube 20 and serves as a guide wire insertion hole 27. 20 is open to the outer surface.
The peripheral edge of the opening 44 of the proximal end 41 of the inner tube 40 and the peripheral edge of the through-hole 27 of the wire port fused part tube wall 26 of the outer tube 20 are airtightly joined by the method according to the present invention described later. It is. The shape of the proximal end opening 44 of the inner tube 40 is not particularly limited, and may take various shapes such as a circle and an ellipse. In this embodiment, the proximal end 41 of the inner tube 40 is cut obliquely. It is elliptical.

  A contrast ring 61 is attached to the outer periphery of a portion of the inner tube 40 that is located in the space for internal expansion 13 of the balloon portion 10. Thus, the contrast ring 61 can be contrasted. Examples of the material of the contrast ring 61 include metals such as gold, platinum, and tungsten.

Although the length of the inner tube 40 may be arbitrary length, it is about 100-500 mm, for example, Preferably it is about 250-350 mm.
In addition, the guide wire insertion hole 27 may be at an arbitrary position of the outer tube 20, but as an example, the guide wire insertion hole 27 is preferably formed within a range of 50 to 450 mm from the distal end portion 22 of the outer tube 20. More preferably, it is in the range of 300 mm.
The outer diameter of the inner tube 40 is determined so that a gap is formed between the inner tube 40 and the inner tube 40, and is not particularly limited. For example, the outer diameter is 0.48 to 0.53 mm, preferably 0.49 to 0.51 mm. is there. Moreover, the inner diameter of the inner tube 12 will not be specifically limited if it is a diameter which can penetrate the guide wire 70, for example, 0.26-0.44mm, Preferably it is 0.30-0.42mm.

  The material constituting the inner tube 40 is preferably composed of a flexible polymer material similar to the balloon portion 10 and the outer tube 20, for example, polyethylene, polyethylene terephthalate, polypropylene, ethylene-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. can be used, preferably Polyethylene, polyamide, and polyimide.

Here, the structure of the wire port fusion | melting part 50 comprised by joining the outer tube 20 and the inner tube 40 is demonstrated in detail.
The wire port fusion part 50 of the balloon catheter 1 of this embodiment is formed in such a form as shown in its axial cross-sectional view in FIG. 2 and in its radial cross-sectional view in FIG.
That is, in the wire port fusion part 50, the balloon expansion lumen 23 formed inside the outer tube 20 is formed in a crescent shape as shown in FIG. 3, and the guide wire lumen formed inside the inner tube 40. 43 is formed in a form having a sufficiently thick side wall around it.

  As described above, the outer shape of the balloon catheter 1 of the present embodiment is formed to 0.86 mm or less, preferably 0.80 to 0.86 mm. Under this condition, the thickness (length a in FIGS. 2 and 3) of the peripheral side wall of the wire port fusion part 50 on the side to be fused with the outer tube 20 of the guide wire lumen 43 should be 0.015 mm or more. Preferably, it is formed to be about 0.026 to 0.06 mm.

The crescent moon shape of the balloon-expanding lumen 23 is a cross-sectional shape defined as follows. The balloon expanding lumen 23 has a cross-sectional shape from a circle (outer circle) drawn with a radius ro with the center co as a center point, to a circle (inner side) with a radius ci smaller than the radius ro with a center ci different from the center co Circle), and the inner circle is cut from the outer circle.
In this embodiment, the center co of the outer circle is the axial center of the outer tube 20, the radius ro of the outer circle is the inner peripheral radius of the outer tube 20, and the center ci of the inner circle is the axial center of the inner tube 40. The radius ri of the circle is the outer radius of the inner tube 40. The center of the outer circle and the center of the inner circle are separated by a radius difference (ri-ro).
Further, in the balloon expanding lumen 23 of the present embodiment, the two end portions 48 are planarly shaped in accordance with the center line of the outer tube 20 in addition to the shape defined by assuming two circles as described above. It has a shape cut into two.

Specifically, in the present embodiment, the radius ri of the inner circle is 0.24 mm or more, preferably 0.25 to 0.30 mm, and the radius ro of the outer circle is 0.365 mm or less, preferably 0.8. The distance ri-ro between the centers of both circles is 0.1 mm or more, and preferably 0.13 to 0.17 mm.
The shape of the balloon-expanding lumen 23 is notched mandrel 73 having a notch 74 that is substantially the same as the cross-sectional shape of the balloon-expanding lumen 23 when the balloon catheter 1 is manufactured, as will be described later. Can be easily formed.

In the balloon catheter 1 of the present embodiment, the shapes of the balloon expansion lumen 23 and the guide wire lumen 43 of the wire port fusion part 50 are further defined as follows.
First, the balloon-expanding lumen 23 is formed so that its cross-sectional area is 24 to 37% of the total cross-sectional area (including the outer diameter) of the catheter 1 in the wire port fusion part 50.
Alternatively, the ratio of the cross-sectional area of the balloon expanding lumen 23 and the guide wire lumen 43 is (the cross sectional area of the balloon expanding lumen 23) / (the cross sectional area of the guide wire lumen 43) = 1.05 to 1.41. Thus, each shape of the balloon expanding lumen 23 and the guide wire lumen 43 is defined.

In the wire port fusion part 50, the thickness of the side wall opposite to the side where the outer tube 20 and the inner tube 40 of the balloon expansion lumen 23 are fused (lower thickness in FIG. 3) is The thickness of the outer tube 20 is substantially equal to, for example, about 0.06 to 0.09 mm, and preferably 0.065 to 0.085 mm.
Moreover, in the wire port fusion | melting part 50, the thickness (thickness of the lower side in FIG. 3) of the side wall on the opposite side to the side by which the outer tube 20 and the inner tube 40 of the guide wire lumen 43 are fuse | melted is It is substantially equal to the thickness of the inner tube 40, for example, about 0.05 to 0.08 mm, and preferably 0.06 to 0.07 mm.

  The connector 60 is a cylindrical body provided with a port therein, and the distal end of the connector 60 is bonded or fused to the proximal end portion 21 of the outer tube 20 so that the port communicates with the balloon expansion lumen 23. Joined by means such as wearing. The proximal end side of the connector 60 is formed in a shape that can be connected to another medical instrument such as a medical tube by screwing or the like. A fluid such as physiological saline is sent from the port of the connector 60 into the internal expansion space 13 of the balloon unit 10 through the balloon expansion lumen 23 of the outer tube 20.

  The material of the connector 60 is not particularly limited. For example, it is preferable to use a thermoplastic resin such as a polypropylene resin, an ABS resin, a polycarbonate resin, a polyamide resin, or a polyacrylate resin.

  The pressure fluid introduced into the balloon expansion lumen 23 of the outer tube 20 and the internal expansion space 13 of the balloon portion 10 through the port of the connector 60 is not particularly limited, but is, for example, physiological saline or radiopaque. A 50/50 mixed aqueous solution of an organic medium and physiological saline is used. The reason why the radiopaque medium is included is to image the positions of the balloon portion 10 and the outer tube 20 using radiation when the balloon catheter 1 is used. The pressure of the pressure fluid for inflating the balloon portion 20 is not particularly limited, but is 3 to 25 atm in absolute pressure, preferably about 4 to 22 atm.

The guide wire 70 is a wire that is inserted into the guide wire lumen 43 of the inner tube 40 in order to guide the balloon catheter 1 into the body cavity.
The guide wire 70 is made of, for example, a single wire or a stranded wire such as stainless steel, copper, copper alloy, titanium, titanium alloy, and the outer diameter is not particularly limited, but is preferably 0.25 to 0.38 mm. More preferably. It is 0.25 to 0.36 mm.

  Moreover, it is preferable that the outer tube 20 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 20 with such a covering material, it is possible to reduce the insertion resistance when the balloon catheter 1 is inserted into a blood vessel or the like. Although the outer periphery of the balloon part 10 may be covered with a covering material, the balloon part 10 expands a stenosis part such as a blood vessel, and the balloon part slides with respect to the stenosis part when the stenosis part is expanded. Is not necessarily preferred. Therefore, in this embodiment, only the outer periphery of the outer tube 20 is covered with a covering material made of a hydrophilic polymer substance.

  The hydrophilic polymer substance includes a natural polymer type and a synthetic polymer type. Examples of the natural polymer type include starch type, cellulose type, tannin / ignin type, polysaccharide type, and protein type. Synthetic polymers include PVA, polyethylene oxide, acrylic acid, maleic anhydride, phthalic acid, water-soluble polyester, ketone aldehyde resin, (meth) acrylamide, vinyl heterocycle, polyamine Examples thereof include a system, a polyelectrolyte, a water-soluble nylon system, and a glycidyl acrylate acrylate system.

  Among these, as the hydrophilic polymer material that can be suitably used as a covering material for the outer tube 20, in particular, a cellulose polymer material (for example, hydroxypropyl cellulose), a polyethylene oxide polymer material (for example, polyethylene glycol). , Maleic anhydride polymer materials (eg, maleic anhydride copolymers such as methyl vinyl ether maleic anhydride copolymer), acrylamide polymer materials (eg, polydimethylacrylamide), water-soluble nylon (eg, manufactured by Toray Industries, Inc.) AQ-nylon P-70) or a derivative thereof. These materials are preferable because a low coefficient of friction can be obtained stably.

  When the monorail balloon catheter 1 is used to expand a stenosis of a blood vessel, first, the guide wire lumen 43 of the inner tube 40 is placed along the guide wire 70 inserted to the stenosis of the blood vessel, so that the balloon portion 10 is guided to the stenosis portion of the blood vessel, and fluid such as physiological saline is sent to the internal expansion space 13 of the balloon portion 10 through the connector 60 and the balloon expansion lumen 23 of the outer tube 20 to expand the balloon portion 10. The stenosis of the blood vessel is expanded.

  Next, a method for manufacturing the balloon catheter 1 having such a configuration will be described with reference to FIGS.

First, a distal outer tube member 31 and a proximal outer tube member 32 that become the outer tube 20 of the balloon catheter 1 and an inner tube member 46 that becomes the inner tube 40 of the balloon catheter 1 are prepared.
The distal outer tube member 31, the proximal outer tube member 32, and the inner tube member 46 all have a lumen along the central axis direction, and each has an outer diameter, an inner diameter, and a thickness as described above. It is a tubular body. Among these, it is preferable that especially the distal outer tube member 31 and the proximal outer tube member 32 have substantially the same outer diameter and thickness. Each of the tube members is made of a flexible polymer material as described above, but is preferably formed of the same material so as to be easily fused to each other.

  With respect to the distal outer tube member 31 and the proximal outer tube member 32, in the present embodiment, a single tube 30 as shown in FIG. 4 (A) is replaced with a central axis as shown in FIG. 4 (B). The distal outer tube member 31 and the proximal outer tube member 32 are obtained by cutting obliquely and dividing.

  The distal outer tube member 31 and the proximal outer tube member 32 are centered on at least one of the proximal end 33 of the distal outer tube member 31 and the distal end 34 of the proximal outer tube member 32. It is preferable to have a shape cut obliquely with respect to the axis, and it is more preferable that both of them have a shape cut obliquely with respect to the central axis. With such a shape, these superpositions can be easily performed. In the present embodiment, as shown in FIG. 4C, the end on the side obliquely cut with respect to the central axis is used as the proximal end portion 33 of the distal outer tube member 31 and the proximal outer tube. The distal end 34 of the member 32 is used.

  In addition, at least one of the proximal end portion 33 of the distal outer tube member 31 and the distal end portion 34 of the proximal outer tube member 32 is shown in FIGS. 4 (C), 5 (A), and 5 (B). ), It is preferable to have the slit 35 along the central axis direction from the peripheral edge. If such a slit 35 is formed, when the proximal end 33 of the distal outer tube member 31 and the distal end 34 of the proximal outer tube member 32 are overlapped, the overlapping region is widened. Therefore, the strength of the periphery of the guide wire insertion opening 27 after fusion can be greatly improved. In the present embodiment, as shown in the drawing, a slit 35 is formed in the distal end portion 34 of the proximal outer tube member 32 along the central axis direction from the peripheral edge of the distal end located closest to the proximal end. The peripheral edge of the slit 35 is a part of the peripheral edge of the distal end 34 of the proximal outer tube member 32.

Such a slit 35 inserts a core rod having an outer diameter slightly smaller than the lumen diameter of the outer tube members 31, 32 into the lumen of the outer tube members 31, 32, It can be easily formed by putting a blade such as a razor in the gap between the tube members 10 and 13 and the core rod and pushing the blade along the core rod. The width of the slit 35 is preferably 0.1 to 1.0 mm, and the length of the slit 35 is preferably 1 to 10 mm.
As shown in FIGS. 5C and 5D, when the slit 35 is formed by narrowing the angle of cutting with respect to the central axis, the same effect can be exhibited.

  As shown in FIG. 4C, the proximal end portion 11 of the balloon portion 10 is previously joined to the distal end portion 36 of the distal outer tube member 31 by means such as fusion or adhesion. Is preferred. However, this joining can also be performed during the formation of the guide wire insertion port or after the formation of the guide wire insertion port.

  When the distal outer tube member 31 and the proximal outer tube member 32 are prepared, the inner tube member 46 is inserted into the lumen of the distal outer tube member 31 as shown in FIG. Before inserting the inner tube member 46 into the lumen of the distal outer tube member 31, a wire-shaped mandrel 71 is inserted into the lumen of the inner tube member 46 to prevent the lumen from being blocked during fusion. It is preferable. The wire-shaped mandrel 71 is a linear body having a substantially circular cross section having an outer diameter substantially equal to the lumen diameter of the inner tube member 46, and is made of a material such as stainless steel, for example. The length of the wire mandrel 71 is not particularly limited as long as it can prevent the lumen from being blocked, but is preferably 10 to 50 mm longer than the inner tube member 46.

  Next, the inner tube member 46 into which the wire-shaped mandrel 71 is inserted is inserted into the lumen of the distal outer tube member 31. At this time, it is preferable to position the proximal end portion 47 of the inner tube member 46 so as to protrude from the proximal end portion 33 of the distal outer tube member 31 by 1 to 5 mm. Further, the proximal end portion 72 of the wire-shaped mandrel 71 is preferably positioned so as to protrude 10 to 20 mm from the proximal end portion 47 of the inner tube member 46.

  Next, as shown in FIG. 7C, an opening 37 surrounded by the periphery of the proximal end 33 of the distal outer tube member 31 and the periphery of the distal end 34 of the proximal outer tube member 32 is formed. As shown in FIG. 7B, the proximal end portion 33 of the distal outer tube member 31 and the distal end portion 34 of the proximal outer tube member 32 are overlapped as shown in FIG. The proximal end 47 of the tube member 46 is exposed outward from the opening 37.

  At this time, before overlapping the proximal end 33 of the distal outer tube member 31 and the distal end 34 of the proximal outer tube member 32, first, as shown in FIG. It is preferable to insert a notch mandrel 73 into the lumen of the side outer tube member 31.

  The notch mandrel 73 is obtained by notching one end side of a round bar having an outer diameter substantially equal to the lumen diameter of the outer tube members 31 and 32, and in this embodiment, a cross section of a portion 74 where the notch is formed. The shape is a substantially crescent shape that is the same as the cross-sectional shape of the balloon-expanding lumen 23 as shown in FIG. The material of the notch mandrel 73 is not particularly limited, but stainless steel or the like is preferable. Further, the length of the notch mandrel 73 is preferably about 100 to 150 mm longer than the proximal outer tube member 32, and the notch is preferably formed with a length of 5 to 20 mm.

  The notch mandrel 73 has a lumen of the distal outer tube member 31 from the end on the notch portion 74 side so as to enter the gap between the outer circumferential surface of the inner tube member 46 and the inner circumferential surface of the distal outer tube member 31. Insert into. Then, the inner tube member 46 is bent in the vicinity of the proximal end portion 33 of the distal outer tube member 31 along the base end of the notch portion 74 of the notch mandrel 73, and the outer peripheral surface of the inner tube member 46 is The proximal end peripheral edge of the distal outer tube member 31 is brought into contact.

  Next, as shown in FIG. 7B, the end of the round bar 75 of the notch mandrel 73 inserted into the lumen of the distal outer tube member 31 is moved far from the lumen of the proximal outer tube member 32. Inserting from the distal end 34 side, the proximal outer tube member 32 is pushed toward the distal outer tube member 31. When the distal end 34 of the proximal outer tube member 32 and the proximal end 33 of the distal outer tube member 31 abut, the distal end 34 of the proximal outer tube member 32 is moved distally. As shown in FIG. 7C, the proximal outer tube member 32 is further pushed forward so as to cover the proximal end portion 33 of the lateral outer tube member 31, and the proximal end portion of the distal outer tube member 31 is pushed forward. 33 and the distal end 34 of the proximal outer tube member 32 form an overlap 38.

  At this time, the inner tube member 46 is positioned in the slit 35 of the proximal outer tube member 32. When the proximal outer tube member 32 is pushed forward until the outer peripheral surface of the inner tube member 46 comes into contact with the proximal end of the slit 35, the peripheral edge of the proximal end portion 33 of the distal outer tube member 31 and the proximal outer tube member 32. An opening 37 surrounded by the periphery of the distal end 34 (the periphery of the slit 35) is formed, and the proximal end 47 of the inner tube member 46 is exposed outward from the opening 37. At this time, as shown in FIG. 7B, the proximal end portion 47 of the inner tube member 46 contacts both the inner peripheral surface of the distal outer tube member 31 and the outer peripheral surface of the proximal outer tube member 32. It is preferable to be in contact.

  The step of inserting the inner tube member 46 into the lumen of the distal outer tube member 31 precedes the step of forming the opening 37 by overlapping the distal outer tube member 31 and the proximal outer tube member 32. It is not necessary to carry out simultaneously. That is, after forming the opening 37 by overlapping the proximal end 33 of the distal outer tube member 31 and the distal end 34 of the proximal outer tube member 32, the wire-shaped mandrel 71 was inserted. The inner tube member 46 may be inserted into the lumen of the distal outer tube member 31 to expose the proximal end portion 47 of the inner tube member 46 outward from the opening 37.

  Next, the proximal end 47 of the inner tube member 46 and the periphery of the opening 37 and the overlapping portion 38 of the distal outer tube member 31 and the proximal outer tube member 32 are fused and integrated. Let The method of fusing is not particularly limited, and various fusing methods such as heat fusing with hot air or a light beam or ultrasonic fusing can be employed. Hereinafter, an example in the case of performing the fusion by heat fusion with hot air will be described.

  For example, in the case where the fusion is performed by hot air, it is preferable to cover the portion to be fused with a heat shrinkable tube 78 as shown in FIG. When using the heat-shrinkable tube 78, the distal-side outer tube member 31 and the proximal-side outer tube member 32 are overlapped with each other before the step of forming the opening 37 is performed. When the step of forming the opening 37 by overlapping the distal outer tube member 31 and the proximal outer tube member 32 is completed, the heat-shrinkable tube 78 is moved to the proximal end 33 side. Shift and cover the part to be fused.

At this time, it is preferable that the distal end of the heat-shrinkable tube 78 is aligned with the proximal end of the notch portion 74 of the notch mandrel 73.
The material of the heat-shrinkable tube 78 is not particularly limited, but a material having relatively excellent heat resistance is preferable. For example, a heat-shrinkable tube made of a fluororesin is preferably used. The length of the heat-shrinkable tube 78 is usually 10 to 30 mm, and the inner diameter of the heat-shrinkable tube 78 is preferably 0.1 to 0.5 mm larger than the outer diameter of the outer tube members 10 and 13. Moreover, the thickness of the heat-shrinkable tube 78 is usually 0.1 to 1.0 mm.

  After the heat-shrinkable tube 78 is put on the part to be fused, for example, the outer tube members 31 and 32 are mounted on a mounting table 80 as shown in FIG. 8, and hot air generated by a hot air generator (not shown) or the like is generated. Is sprayed toward the heat shrinkable tube 78. The inner tube member 46 and the outer tube members 31 and 32 are softened by the hot air, and the heat-shrinkable tube 78 is contracted to contact the inner tube member 46 and the outer tube members 31 and 32 and the distal outer tube member 31. An external force is applied to the overlapping portion 38 of the proximal outer tube member 32. The temperature of the hot air and the injection time vary depending on the material of the inner tube member 46 and the outer tube members 31 and 32 and the type of the heat shrinkable tube 78, but the temperature is usually 150 to 250 ° C. and the injection time is 10 to 60. Seconds.

  When the hot air injection is completed, cooling is performed by, for example, injecting the cold air toward the heat shrinkable tube 78, and then the heat shrinkable tube 78 is cut and removed, and the wire-shaped mandrel 71 and the notched mandrel 73 are extracted. If there is an unnecessary portion such as a portion in which the inner tube member 46 protrudes outward from the outer tube members 31 and 32, the unnecessary portion is cut off with a razor or the like. By this operation, the proximal end portion 47 of the inner tube member 46 and the 37 edge of the opening, and the overlapping portion 38 of the distal outer tube member 31 and the proximal outer tube member 32 are fused and integrated. Thus, a guide wire insertion opening 27 as shown in FIG. 2 is formed.

  After the guide wire insertion port 27 is formed in this way, the distal end portion 12 of the balloon portion 10 is joined to the distal end portion 42 of the inner tube 40 by means such as fusion or adhesion, and the proximal end The monorail balloon catheter 1 can be manufactured by joining the connector 60 to the proximal end portion of the lateral tube member 32 by means such as fusion or adhesion.

The wall thickness and pressure strength of the balloon catheter 1 of this embodiment configured as described above are shown in FIGS. 10 and 11 in comparison with a conventional balloon catheter.
For example, in a balloon catheter manufactured to have an outer diameter of 0.86 mm or less by a conventional manufacturing method, the thickness of the upper portion of the guide wire lumen 43 (the inner side on the side where the inner tube 40 and the outer tube 20 are fused) As shown in FIG. 10, the thickness of the tube 40 was as thin as an average of 0.009 mm. For this reason, the pressure strength is drastically lowered as shown in FIG.
On the contrary, when the thickness of the upper part of the guide wire lumen 43 is secured to some extent and the pressure strength is maintained to some extent, the outer diameter of the balloon catheter 1 is 0.92 to 1. He had to be as thick as 03 mm.

On the other hand, in the balloon catheter 1 according to the present invention manufactured by the manufacturing method according to the present invention, the thickness of the upper portion of the guide wire lumen 43 is as shown in FIG. 10 even when the outer diameter is 0.86 mm or less. As shown in FIG. 11, the average pressure is 0.03 mm or more, and the pressure strength is low in proportion to the thickness as shown in FIG. 11, and is not drastically reduced.
Thus, the balloon catheter 1 according to the present invention manufactured by the manufacturing method according to the present invention is a balloon catheter 1 having a high pressure resistance but a small diameter.

  As described above, the balloon catheter 1 of the present embodiment is a balloon catheter in which the wire port fusion portion 50 (guide wire insertion hole 27) has a sufficient pressure resistance while being small in diameter. Further, the balloon expanding lumen 23 and the guide wire lumen 43 also have a sufficient cross-sectional area, so that the balloon catheter 1 has good operability.

  Moreover, in the manufacturing method of the balloon catheter 1 of this embodiment, the wire port fusion | melting part 50 is used by using the notch mandrel 73 which has the notch part 74 of the substantially same cross-sectional shape as the cross-sectional shape of the lumen 23 for balloon expansion. It can be easily formed in the form as described above.

  The above-described embodiments are described for facilitating understanding of the present invention, and do not limit the present invention. Each element disclosed in the present embodiment includes all design changes and equivalents belonging to the technical scope of the present invention, and various suitable modifications can be made.

For example, the cross-sectional shape of the balloon expansion lumen 23 in the wire port fusion part 50 is not limited to the shape shown in FIG. 3, but is arbitrary.
For example, in the balloon catheter 1 of the above-described embodiment, the balloon expanding lumen 23 has a cross-sectional shape that is defined by assuming two circles as shown in FIG. Both ends are cut into a planar shape according to the center line. However, for example, as shown in FIG. 9 (A), both ends may be left sharp without being cut, or both ends are chamfered as shown in FIG. 9 (B). It may be a shape. In the case of R chamfering, in the example of dimensions of the above-described embodiment, for example, it is preferable that both ends are R chamfered at r = 0.01 to 0.1 mm.

  Further, the sectional shape of the balloon-expanding lumen 23 is not defined by assuming two circles, but an effective angle θ of one circle (outer circle) is defined as shown in FIG. 9C. By doing so, you may prescribe | regulate as a fan shape of desired center angle (theta).

  In any of these cases, as described above, the cross-sectional area of the balloon-expanding lumen 23 is 24 to 37% of the total cross-sectional area (including the outer diameter) of the catheter 1 in the wire port fusion part 50, or The ratio of the cross-sectional area between the balloon-expanding lumen 23 and the guidewire lumen 43 (the cross-sectional area of the balloon-expanding lumen 23) / (the cross-sectional area of the guidewire lumen 43) is set to 1.05 to 1.41. The effects of the present invention can be sufficiently obtained.

  The present invention expands a narrowed portion formed in a blood vessel or other body cavity in, for example, percutaneous coronary angioplasty (PTCA), dilation of blood vessels such as extremities, upper ureter dilation or renal vasodilatation. The present invention can be used in a balloon catheter used for manufacturing and a manufacturing method thereof.

DESCRIPTION OF SYMBOLS 1 ... PTCA balloon catheter 10 ... Balloon part 11 ... Proximal end part 12 ... Distal end part 13 ... Space for internal expansion 20 ... Outer tube (outer shaft)
DESCRIPTION OF SYMBOLS 21 ... Proximal end part 22 ... Distal end part 23 ... Lumen for balloon expansion 26 ... Wire port fusion part tube wall 27 ... Through-hole (guide wire insertion hole)
31 ... Distal outer tube member
33 ... Proximal end
36 ... Distal end 32 ... Proximal outer tube member
34 ... Distal end
35 ... slit 37 ... opening 38 ... overlapping part 40 ... inner tube (guide wire shaft)
41 ... Proximal end 42 ... Distal end 43 ... Guide wire lumen 44 ... Proximal end opening 45 ... Distal end opening 46 ... Inner tube member
47 ... Proximal end portion 48 ... Both end portions 50 ... Wire port fused portion 50
DESCRIPTION OF SYMBOLS 60 ... Connector 61 ... Contrast ring 70 ... Guide wire 71 ... Wire-shaped mandrel 72 ... Proximal end part 73 ... Notch mandrel 74 ... Notch side (notch part)
75 ... Round bar side 78 ... Heat shrink tube 80 ... Place

Claims (7)

An outer tube having a balloon expansion lumen formed therein along the axial direction;
A guide wire lumen is formed inside, an inner tube extending in an axial direction inside the balloon expanding lumen of the outer tube;
A balloon portion having an expansion space communicating with the balloon expansion lumen, wherein a proximal end portion of the balloon portion is joined to a distal end portion of the outer tube, and a distal end portion of the inner tube A balloon part to which the distal end of the balloon part is joined;
A balloon catheter having a wire port fused portion in which a proximal end portion of the inner tube penetrates the tube wall in the longitudinal direction of the outer tube and is opened to the outside; ,
At least the outer diameter of the outer tube in the wire port fusion part is 0.86 mm or less, and the inner tube forming the guide wire lumen in the wire port fusion part is fused to the outer tube. A balloon catheter having a side wall thickness of 0.015 mm or more.   2. The balloon catheter according to claim 1, wherein a cross-sectional shape of the balloon expansion lumen in the wire port fusion part is formed in a substantially crescent shape.   The balloon according to claim 1 or 2, wherein a cross-sectional area of the balloon dilating lumen is 24 to 37% of a total catheter cross-sectional area of the wire port fusion part in the wire port fusion part. catheter.   In the wire port fusion part, the cross-sectional area ratio of the balloon dilating lumen and the guide wire lumen, (the cross-sectional area of the balloon dilating lumen) / (the cross-sectional area of the guide wire lumen) is 1.05 to 1.41. The balloon catheter according to any one of claims 1 to 3, wherein   The thickness of the side wall of the inner tube forming the guide wire lumen in the wire port fused portion on the side opposite to the side fused with the outer tube is 0.05 mm or more. The balloon catheter according to any one of claims 1 to 4.   The thickness of the side wall of the outer tube that forms the balloon expansion lumen in the wire port fused portion on the side opposite to the side fused with the inner tube is 0.06 mm or more. The balloon catheter according to any one of claims 1 to 5. Inserting the inner tube member into the lumen of the distal outer tube member;
Using a notch mandrel in which one end side is formed in a circular cross-section having the same diameter as the inside of the lumen of the proximal outer tube member, and the other end side is formed in a cutout portion having a substantially crescent-shaped cross section The proximal end of the distal outer tube member so that the notched portion of the notched mandrel enters the gap between the outer peripheral surface of the inner tube member and the inner peripheral surface of the distal outer tube member. The inner tube member is bent near the proximal end of the distal outer tube member along the proximal end of the notched portion of the notched mandrel. Process,
The distal end of the proximal outer tube member is inserted into the distal end of the cutout mandrel, and the proximal outer tube member is inserted into the distal outer side. Pushing toward the tube member to form an overlap between the proximal end of the distal outer tube member and the distal end of the proximal outer tube member; and the distal outer tube member Forming an opening surrounded by the periphery of the proximal end of the proximal end and the periphery of the distal end of the proximal outer tube member, and the proximal end of the inner tube member is outwardly formed from the formed opening. Exposing to
A step of fusing and integrating the proximal end portion of the inner tube member and the peripheral edge of the opening, and the overlapping portion of the distal outer tube member and the proximal outer tube member. A method for manufacturing a catheter.

Images