WO2013122002A1

WO2013122002A1 - Balloon catheter

Info

Publication number: WO2013122002A1
Application number: PCT/JP2013/053065
Authority: WO
Inventors: 達也川瀬
Original assignee: テルモ・クリニカルサプライ株式会社
Priority date: 2012-02-16
Filing date: 2013-02-08
Publication date: 2013-08-22

Abstract

Provided is a balloon catheter (1) comprising an inner tube (3), an outer tube (2), and a balloon (4) having a tip section (42) that is fixed to the inner tube (3) and a rear end section (44) that is attached to the external tube (2). The balloon (4) comprises an expandable section (41), a cylindrical section (43) that is positioned between the expandable section (41) and the rear end section (44) and that extends to a predetermined length, and an inclined rear end surface (45) that is inclined with respect to the central axis of the cylindrical section (43). The tip section of the outer tube (2) comprises an inclined tip surface (21) that is inclined with respect to the central axis of the outer tube (2). The tip section of the outer tube (2) and the rear end section of the balloon (4) are fixed together by means of an inclined annular fixing section (6) that is formed on the parts of the two sections that overlap with one another, is inclined with respect to the central axis of the outer tube, and is formed to have a band shape that is airtight.

Description

Balloon catheter

The present invention relates to a balloon catheter, and more particularly to a balloon catheter that is inserted into a small-diameter body cavity such as a blood vessel or a bile duct.

The balloon catheter is used for angiography, injection of a chemical solution such as a chemotherapeutic agent, embolization, percutaneous coronary artery dilatation (PTCA), percutaneous arterial dilatation (PTA) and the like.
As a balloon catheter, there is JP-A-2005-103120 proposed by the applicant of the present application.
The balloon catheter 1 of Patent Document 1 includes a double-tube catheter main body 3 including an inner tube 9 and an outer tube 21. A balloon 7 is attached to the distal end portion of the catheter body, and an infusate passage 23 formed between the inner tube and the outer tube is communicated with the balloon 7 through the distal end opening 22 of the outer tube.

JP-A-2005-103120

Balloon catheters such as Patent Document 1 have recently been required to be inserted into thinner blood vessels, and in order to improve blood vessel insertion, changes in physical properties at the distal end are gentle. It is desirable that

Accordingly, an object of the present invention is to provide an inner tube, an outer tube that is provided coaxially with the inner tube, protrudes from the distal end of the inner tube, a balloon having a distal end fixed to the inner tube and a rear end fixed to the outer tube. A balloon catheter that has a gentle change in physical properties at the fixing portion between the balloon and the outer tube, prevents kinking caused by the two, and improves the operability of insertion into the body cavity A catheter is provided.

What achieves the above object is as follows.
An inner tube having a first lumen and a second lumen provided coaxially with the inner tube, having a tip at a position retracted by a predetermined length from the tip of the inner tube, and the outer surface of the inner tube A balloon catheter comprising: an outer tube having a distal end fixed to the inner tube; a rear end fixed to the distal end of the outer tube; and an expandable balloon having an interior communicating with the second lumen The balloon has an expandable portion formed on the rear end side from the tip portion, and a tubular shape formed between the expandable portion and the rear end portion and extending a predetermined length in the rear end direction. And the rear end portion includes an inclined rear end surface that is inclined with respect to the central axis of the cylindrical portion, and the distal end portion of the outer tube is positioned on the central axis of the outer tube. An inclined tip surface that is slanted with respect to the tip of the outer tube and the balloon The end portion has a portion that overlaps in the axial direction of the balloon catheter, and the distal end portion of the outer tube and the rear end portion of the balloon are provided in the overlapping portion, and are arranged on the central axis of the outer tube. A balloon catheter fixed by a band-shaped inclined annular fixing portion that is inclined and airtight.

FIG. 1 is a partially omitted external view of an embodiment of a balloon catheter according to the present invention. FIG. 2 is an enlarged external view of the distal end portion of the balloon catheter shown in FIG. FIG. 3 is a longitudinal sectional view of FIG. 4 is an enlarged longitudinal sectional view of a proximal end portion of the balloon catheter shown in FIG. FIG. 5 is an explanatory view for explaining a fixing portion between the balloon rear end portion and the outer tube front end portion of the balloon catheter of the present invention. FIG. 6 is an explanatory view for explaining a fixing portion between the balloon rear end portion and the outer tube front end portion of the balloon catheter of the present invention. FIG. 7 is an explanatory view for explaining a fixing portion between the balloon rear end portion and the outer tube front end portion of the balloon catheter of the present invention. FIG. 8 is an enlarged external view of the vicinity of a fixing portion between a balloon rear end portion and an outer tube front end portion of a balloon catheter according to another embodiment of the present invention. FIG. 9 is a longitudinal sectional view of FIG. FIG. 10 is an enlarged external view of the vicinity of a fixing portion between a balloon rear end portion and an outer tube front end portion of a balloon catheter according to another embodiment of the present invention. FIG. 11 is a longitudinal sectional view of FIG. FIG. 12 is an enlarged cross-sectional view of the vicinity of a fixing portion between a balloon rear end portion and an outer tube front end portion of a balloon catheter according to another embodiment of the present invention. FIG. 13 is an enlarged external view of the vicinity of a fixing portion between a balloon rear end portion and an outer tube front end portion of a balloon catheter according to another embodiment of the present invention. FIG. 14 is a longitudinal sectional view of FIG. FIG. 15 is an enlarged external view of the vicinity of a fixing portion between a balloon rear end portion and an outer tube front end portion of a balloon catheter according to another embodiment of the present invention. 16 is a longitudinal sectional view of FIG. FIG. 17 is an explanatory diagram for explaining a fixing portion between a balloon rear end portion and an outer tube front end portion of a balloon catheter according to another embodiment of the present invention.

The balloon catheter of the present invention will be described with reference to the embodiments shown in the drawings.
The balloon catheter 1 of the present invention is provided with an inner tube 3 having a first lumen 11, and coaxially with the inner tube 3, and has a distal end at a position retracted by a predetermined length from the distal end of the inner tube 3. The outer tube 2 forming the second lumen 12 between the outer tube 2 and the outer tube 2, the front end 42 is fixed to the inner tube 3, the rear end 44 is fixed to the outer tube 2, and the inner portion is connected to the second lumen 12. And an expandable balloon 4 in communication therewith. The balloon 4 has an expandable portion 41 formed on the rear end side of the front end portion 42, and a tubular portion (between the expandable portion 41 and the rear end portion 44 and extending a predetermined length in the rear end direction. Sleeve) 43, and the rear end portion 44 includes an inclined rear end surface 45 that is inclined with respect to the central axis of the cylindrical portion 43. The distal end portion of the outer tube 2 includes an inclined distal end surface 21 that is inclined with respect to the central axis of the outer tube 2. The distal end portion of the outer tube 2 and the rear end portion 44 of the balloon 4 have a portion overlapping in the axial direction of the balloon catheter 1, and the distal end portion of the outer tube 2 and the rear end portion 44 of the balloon 4 overlap each other. It is fixed by a belt-like inclined annular fixing portion 6 provided in the portion, inclined with respect to the central axis of the outer tube 2 and formed airtight.

The balloon catheter 1 of this embodiment is formed by an outer tube 2, an inner tube 3, a balloon 4 and a branch hub 5.
The inner tube 3 is a tube body having a first lumen 11 whose tip is open. The first lumen 11 is used for insertion of a guide wire, injection of a chemical solution, and the like. In the balloon catheter 1 of this embodiment, the first lumen 11 of the inner tube 3 communicates with the first opening 54 provided in the branch hub 5.

The inner tube 3 preferably has an outer diameter of 0.60 to 1.63 mm, particularly preferably 0.62 to 0.68 mm, and an inner diameter of 0.40 to 1.33 mm. And particularly preferably 0.43 to 0.50 mm.
The inner tube 3 is inserted into the outer tube 2, and the tip of the inner tube 3 protrudes from the outer tube 2. A second lumen (balloon expansion lumen) 12 is formed between the outer surface of the inner tube 3 and the inner surface of the outer tube 2 and has a sufficient volume.

In the inner tube 3, a contrast marker 32 is fixed to the distal end (slightly proximal side of the distal end 31, near the distal end 42 of the balloon 4). The contrast marker is preferably formed of a radiopaque material (for example, gold, platinum, tungsten, or an alloy thereof, or a silver-palladium alloy, a platinum-iridium alloy, or the like). By doing in this way, the front-end | tip part of the balloon catheter 1 can be confirmed by X-ray contrast.
Further, in this embodiment, as shown in FIG. 1, the inner tube 3 is continuous with the first flexible region 3a and the first region 3a from the distal end side, and is flexible, but the first flexible region. A second flexible region 3b having a hardness higher than 3a and a third region 3c that is continuous with the second flexible region 3b and has a hardness higher than that of the second flexible region 3b. In particular, in this embodiment, as shown in FIG. 1, the most flexible first flexible region 3a extends from the distal end of the inner tube 3 in the rear end direction, and the rear end of the first flexible region 3a is an outer portion to be described later. It passes over the belt-like inclined annular fixing portion 6 between the tube 2 and the cylindrical portion of the balloon 4 and is located on the rear end side of a predetermined length. The length of the first region 3a is preferably 100 to 350 mm, and particularly preferably 200 to 300 mm. The hardness of the first region 3a is preferably 30 to 40D (Shore D hardness). The length of the second flexible region 3b that is continuous with the first flexible region 3a is preferably 100 to 350 mm, and particularly preferably 200 to 300 mm. The hardness of the second region 3a is preferably 40 to 55D (Shore D hardness), and preferably 5 to 15D (Shore D hardness) higher than the first flexible region. Further, the length of the third region 3c continuous with the second flexible region 3b is preferably 500 to 1500 mm, and particularly preferably 800 to 1200 mm. The hardness of the third region 3c is preferably 55 to 85D (Shore D hardness), and preferably 15 to 40D (Shore D hardness) hardness higher than that of the second flexible region.

The outer tube 2 is a tube body that is inserted in the inner tube 3 and located at a portion (predetermined length base end side) whose tip is retracted by a predetermined length from the tip of the inner tube 3. The distal end of the second lumen 12 communicates with the rear end portion of the balloon 4 to be described later, and the rear end of the second lumen 12 is provided on the branch hub 5 and is a fluid for inflating the balloon (for example, the balloon It communicates with the second opening 55 of the injection port 53 for injecting an expansion liquid (specifically, an angiographic agent).
The outer tube 2 preferably has an outer diameter of 0.85 to 2.03 mm, particularly preferably 0.87 to 0.95 mm, and an inner diameter of 0.70 to 1.83 mm. And particularly preferably 0.72 to 0.80 mm.
The outer tube 2 includes an inclined distal end surface 21 that is inclined with respect to the central axis of the outer tube 2 at the distal end.

The material for forming the outer tube 2 and the inner tube 3 is preferably a material having a certain degree of hardness and a certain degree of flexibility. For example, polyolefins such as polyethylene and polypropylene, polyamides such as polyamide and polyethylene terephthalate, PTFE, Fluorine-based polymers such as ETFE, PEEK (polyetheretherketone), polyimide, olefin-based elastomer (for example, polyethylene elastomer, polypropylene elastomer), polyamide elastomer, styrene-based elastomer (for example, styrene-butadiene-styrene copolymer, styrene) -Isoprene-styrene copolymer, styrene-ethylenebutylene-styrene copolymer), polyurethane, urethane elastomer, fluororesin elastomer, etc. Synthetic resin elastomer, urethane rubber, silicone rubber, synthetic rubbers such as butadiene rubber, a rubber such as natural rubber, such as latex rubber is used.
Further, the outer tube 2 and the inner tube 3 may be provided with a rigidity imparting body 35. As the rigidity imparting body, a blade formed of a metal wire or a synthetic resin wire is preferable. And when providing a rigidity imparting body in the inner tube 3, it is desirable to provide it in the whole except a front-end | tip part, as shown in FIG. Specifically, it is preferable to provide from the contrast marker 32 to the base end.

As the balloon 4, an expandable one, a foldable one, an expandable and foldable one, or the like is used. In the catheter of this embodiment, the balloon can be folded on the outer periphery of the inner tube 3 and can be restored to a molded form and expanded (expanded) by the balloon expanding fluid. It is used.
Examples of the material for forming the balloon 4 include polyolefin, polyvinyl chloride, polyamide, polyester, polyarylene sulfide, and the like, and synthetic resin elastomers such as polyamide elastomer, polyester elastomer, and urethane elastomer, silicone rubber, latex rubber, and the like. The rubber material can be used. In particular, polyurethane-based thermoplastic elastomers (for example, aromatic polyurethane-based thermoplastic elastomers, aliphatic polyurethane-based thermoplastic elastomers, etc. are preferred. Examples of polyurethane-based thermoplastic elastomers include aromatic and aliphatic thermoplastic elastomer polyurethanes. It is done.
The balloon 4 has higher flexibility and flexibility than the outer tube 2. In particular, the balloon 4 is preferably higher in flexibility and flexibility than the inner tube 3 and the outer tube 2.

The balloon 4 has an expandable part 41 formed on the rear end side from the front end part 42, and a cylindrical part (in other words, formed between the expandable part 41 and the rear end part 44 and extending a predetermined length in the rear end direction. ), And the rear end portion 44 includes an inclined rear end surface 45 that is inclined with respect to the central axis of the cylindrical portion 43. The rear end portion 44 of the balloon 4 and the distal end portion of the outer tube 2 are fixed by a band-shaped inclined annular fixing portion 6 that is inclined with respect to the central axis of the outer tube 2 and is hermetically formed.
The distal end portion 42 of the balloon 4 is a cylindrical portion that extends a predetermined length from the distal end of the expandable portion 41 and is fixed to the distal end portion of the inner tube 3. The distal end portion 42 of the balloon 4 has a smaller outer diameter than the cylindrical portion (sleeve) 43 provided on the rear end side from the expandable portion 41. In addition, it is preferable that the tip end of the distal end portion 42 of the balloon 4 is located at the rear end of the contrast marker 32 or close without reaching the rear end. Further, it is preferable that the distal end portion 42 of the balloon 4 does not cover the contrast marker 32. The distal end portion 42 of the balloon 4 is preferably fixed to the inner tube 3 by heat sealing.
The expandable portion 41 is expanded by the injected liquid and can be in close contact with the inner wall of a body cavity (specifically, a blood vessel). The distal end portion 42 is a short cylindrical portion extending with substantially the same outer diameter. The cylindrical portion 43 formed between the expandable portion 41 and the rear end portion 44 extends with substantially the same outer diameter, and has a length longer in the axial direction than the front end portion 42. The cylindrical portion 43 forms a passage 13 that communicates with the second lumen 12 by the inner surface and the inner surface of the inner tube 3. By providing such a cylindrical portion 43 extending in the predetermined long axis direction between the expandable portion 41 and the rear end portion 44, the portion is more flexible than the outer tube 2, and thus is easily deformed. Low profile (thinning at the time of in vivo insertion) becomes possible, and insertion into a smaller body cavity (for example, blood vessel) becomes easier.

As the balloon 4, the outer diameter of the expandable portion 41 at the time of maximum expansion is preferably 3.0 to 15.0 mm, and particularly preferably 4.0 to 8.0 mm. Further, the length of the expandable portion 41 is preferably 3.5 to 14.5 mm, and particularly preferably 4.0 to 5.5 mm. The outer diameter of the tip 42 is preferably 0.77 to 1.85 mm, particularly preferably 0.80 to 0.90 mm, and the length is 1.0 to 3.0 mm. It is preferably 1.5 to 2.5 mm. The outer diameter of the cylindrical portion 43 is preferably 0.90 to 2.10 mm, particularly preferably 0.93 to 1.00 mm, and the length is preferably 10 to 60 mm. Particularly preferred is 15 to 30 mm.
Moreover, the expandable part 41 of the balloon 4 is thinner than the tip part 42 and the cylindrical part 43, and is easy to expand and expand with the expansion liquid to be injected. The wall thickness of the expandable portion 41 is preferably 0.03 to 0.18 mm thinner than the tubular portion 43 and the tip portion 42, and particularly preferably 0.04 to 0.11 mm thinner. Further, the thickness of the cylindrical portion 43 and the tip portion 42 is preferably 0.07 to 0.20 mm, and particularly preferably 0.08 to 0.15 mm.

The inclined annular fixing portion 6 (in other words, the inclined annular joint portion) for joining the rear end portion 44 of the balloon 4 and the distal end portion of the outer tube 2 in the balloon catheter of this embodiment will be described with reference to FIGS. To do.
As described above, the distal end portion of the outer tube 2 includes the inclined distal end surface 21 that is inclined with respect to the central axis of the outer tube 2, and the balloon 4 is disposed at the rear end portion 44 with respect to the central axis of the tubular portion 43. And an inclined rear end face 45 that is slanted. And the front-end | tip part of the outer tube | pipe 2 and the rear-end part 44 of the balloon 4 have a part which overlaps with the axial direction of a balloon catheter. Further, a belt-shaped inclined annular fixing portion 6 provided at an overlapping portion of the distal end portion of the outer tube 2 and the rear end portion 44 of the balloon 4 and inclined with respect to the central axis of the outer tube 2 and formed airtight. I have. The outer tube 2 and the balloon 4 are fixed by the inclined annular fixing portion 6. Since the cylindrical portion 43 and the rear end portion 44 of the balloon 4 are more flexible and flexible than the distal end portion of the outer tube 2, the inclined annular fixing portion 6 is formed from the rear end side to the distal end side. Flexibility toward the side increases. Therefore, a sharp property change point in the vicinity of the distal end portion of the outer tube 2 is not formed, and the occurrence of kinks is prevented and the film has good deformability.

In particular, in the balloon catheter 1 of this embodiment, the rear end portion 44 of the balloon 4 is an enlarged diameter portion (in other words, an inclined enlarged diameter portion, an inclined bulging portion), and the rear end face 45 is a cylindrical portion. It is an inclined rear end face inclined by a predetermined angle with respect to the central axis of 43 (outer tube 2). In addition, the distal end portion of the outer tube 2 enters the rear end portion 44 whose diameter has been increased, and this entering portion forms a portion where the distal end portion of the outer tube 2 and the rear end portion 44 of the balloon 4 overlap. The outer tube 2 has substantially the same outer diameter as the cylindrical portion 43 of the balloon 4, and the rear end portion 44 of the balloon 4 is in a bulged state.

In the balloon catheter 1 of this embodiment, as shown in FIG. 6, the inclined rear end surface 45 of the balloon 4 and the inclined front end surface 21 of the outer tube 2 are substantially parallel or have different inclination angles with respect to the central axis of the outer tube. 44 degrees or less, preferably 20 degrees or less. As shown in FIG. 6, an inclination angle A with respect to the central axis of the cylindrical portion 43 (outer tube 2) of the inclined rear end surface 45 of the balloon 4 is relative to the central axis of the outer tube 2 of the inclined distal end surface 21 of the outer tube 2. It is preferable that the inclination angle B is large. The inclination angle A of the inclined rear end face 45 of the balloon 4 with respect to the central axis of the tubular portion 43 (outer tube 2) is preferably 20 degrees to 30 degrees, and more preferably 22 degrees to 28 degrees. In addition, the inclination angle B of the inclined tip surface 21 of the outer tube 2 with respect to the central axis of the outer tube 2 is preferably 30 to 45 degrees, and particularly preferably 35 to 43 degrees.

And the front-end | tip part of the outer tube | pipe 2 which entered into the rear-end part 44 which the diameter of the balloon 4 expanded is airtightly fixed to the balloon 4, and forms the strip | belt-shaped inclined annular fixing part 6. FIG. The inclined annular fixing portion 6 has an annular fixing surface 61. The annular fixing portion 61 is formed on the entire inner surface of the proximal end portion 44 of the balloon 4 that contacts the outer surface of the distal end portion of the outer tube 2 of the inclined annular fixing portion 6. In addition, as will be described later, a non-fixed portion that does not affect the airtightness between the two may be included.
It is preferable that the annular fixing portion 61 has substantially the same width or gradually becomes wider toward the rear end. In the balloon catheter 1 of this embodiment, as shown in FIG. 6, the annular fixing portion 61 is gradually widened toward the rear end.

Further, in the balloon catheter 1 shown in FIG. 6, the imaginary line connecting the tip 22 of the inclined distal end surface 21 of the outer tube 2 and the tip 46 of the inclined rear end surface 45 of the balloon 4 is substantially parallel to the central axis of the outer tube 2. It has become. In other words, the distal end 22 of the inclined distal end surface 21 of the outer tube 2 is positioned substantially in front of the distal end 46 of the inclined rear end surface 45 of the balloon 4. Similarly, an imaginary line connecting the rear end 23 of the inclined distal end surface 21 of the outer tube 2 and the rear end 47 of the inclined rear end surface 46 of the balloon 4 is substantially parallel to the central axis of the outer tube 2. That is, the rear end 23 of the inclined front end surface 21 of the outer tube 2 is positioned substantially in front of the rear end 47 of the rear end surface 45 of the balloon 4 in the front end direction. For this reason, a narrow portion is not formed in the annular fixing portion 61.

Furthermore, in this embodiment, the tip 46 of the inclined rear end surface 45 of the balloon 4 is located on the front end side from the rear end 23 of the inclined front end surface 21 of the outer tube 2. For this reason, the physical property of the inclined annular fixing portion 6 continuously changes. Since the cylindrical portion 43 and the rear end portion 44 of the balloon 4 are more flexible and flexible than the distal end portion of the outer tube 2, the inclined annular fixing portion 6 is formed from the rear end side to the distal end side. Flexibility and softness gradually increase toward the side. In particular, in the inclined annular fixing portion 6 of this embodiment, the portion where the rear end portion of the balloon 4 covers the front end portion of the outer tube 2 is increased from the rear end side, and the rear end of the inclined front end surface 21 of the outer tube 2 is increased. Beyond the end 23, the rear end portion 44 of the balloon 4 continues to increase in cross-sectional area perpendicular to the axial direction, but decreases in cross-sectional area perpendicular to the axial direction of the distal end portion of the outer tube 2. And in the front-end | tip 46 of the inclined surface 45 of the rear-end part 44 of the balloon 4, the cross section of the rear-end part 44 becomes cyclic | annular, Furthermore, the front-end | tip part of the outer tube 2 reduces the cross-sectional area in the front, Terminate at the tip 22. In other words, in the present embodiment, the inclined annular fixing portion 6 is entirely formed on the cutting surface orthogonal to the central axis of the outer tube 2 so that the rear end portion 44 of the balloon 4 and the distal end portion of the outer tube 2 are both annular. It is something that has no part.

The distance P between the distal end 22 of the outer tube 2 and the distal end 46 of the inclined rear end face 45 of the balloon 4 in FIG. 6 is preferably 0.50 to 1.50 mm, particularly 0.6 to 1.0 mm. It is preferable that The distance N between the rear end 23 of the inclined front end surface 21 of the outer tube 2 and the rear end 47 of the inclined rear end surface 45 of the balloon 4 is preferably 0.50 to 4.0 mm, particularly 0.6. It is preferable that the thickness is ˜1.0 mm. The axial length L of the inclined annular fixing portion 6 (in other words, the distance L between the distal end 22 of the outer tube 2 and the rear end 47 of the inclined rear end face 45 of the balloon 4) is 2.0 to 8.0 mm. In particular, the thickness is preferably 2.3 to 3.5 mm. The distance M between the rear end 23 of the inclined front end surface 21 of the outer tube 2 and the front end 46 of the inclined rear end surface 45 of the balloon 4 is preferably 0.6 to 2.5 mm, particularly 0.8 to It is preferable that it is 1.5 mm.
The distance M between the rear end 23 of the inclined distal end surface 21 of the outer tube 2 and the distal end 46 of the inclined rear end surface 45 of the balloon 4 is 0, that is, the inclined distal end of the outer tube 2 as in the embodiment shown in FIG. The rear end 23 of the surface 21 and the tip 46 of the inclined rear end surface 45 of the balloon 4 may be located at the same position in the axial direction of the outer tube 2. The rear end 23 of the inclined front end surface 21 of the outer tube 2 is preferably not located on the front end side of the front end 46 of the inclined rear end surface 45 of the balloon 4.

In addition, as shown in FIG. 7, for example, the inclined annular fixing portion 6 is heated to an overlapped portion and about 2 mm before and after the end portion of the outer tube 2 is inserted into the rear end portion 44 of the balloon 4. The shrinkable tube is fitted, and the heat shrinkable tube is heated from the outer surface by the heat mold 7 so as to be fused together. And the outer edge of the inclined front end surface of the outer tube 2 is rounded with no edges due to melting. Moreover, in this fusion | melting process, as shown in FIG. 7, you may carry out so that the front-end | tip part of the inclination front end surface 21 of the outer tube 2 may not be heated directly. By doing in this way, the non-fusion | fusion part 71 or the weak melt | fusion part with the rear-end part of the balloon 4 can be formed in the front-end | tip of the outer tube | pipe 2. By forming such a weakly fused portion, in other words, the rear end portion of the balloon 4 where the outer tube 2 does not exist (the portion that does not overlap) is not heated and compressed by the heat-shrinkable tube, The formation of a thin portion in the seal portion is prevented.

Further, the joining form of the rear end portion of the balloon 4 and the front end portion of the outer tube 2 is not limited to the above-described one, but the type provided in the balloon catheter 10 of the embodiment shown in FIGS. 8 and 9. It may be.
In the balloon catheter 10 of this embodiment, the distal end portion of the outer tube 2 is an inclined small diameter portion 25, and an inclined distal end surface 21 is formed at the distal end thereof. Further, the outer diameter of the rear end portion 44 of the balloon 4 is substantially the same as the outer diameter of the outer tube main body portion on the proximal end side from the inclined small diameter portion of the outer tube 2. The inclined small-diameter portion of the outer tube 2 is inserted and fixed in the inclined rear end portion 44 of the balloon 4 to form the inclined annular fixing portion 6a. In this balloon catheter 10, the rear end portion 44 of the balloon 4 is an inclined bulging portion, and the rear end side thereof extends to the rear end portion of the outer tube 2 with substantially the same outer diameter. It has become. Further, the joint end of the balloon 4 and the outer tube 2 exposed on the outer surface of the catheter 10 does not have a step.
Further, the joining form of the rear end portion of the balloon 4 and the distal end portion of the outer tube 2 may be of the type provided in the balloon catheter 20 of the embodiment shown in FIGS. 10 and 11.

In the balloon catheter 20 of this embodiment, the rear end portion of the balloon 4 is not an inclined diameter-expanded portion, and is formed by extending the tubular portion 43 as it is and terminating obliquely. And the front-end | tip part of the outer tube | pipe 2 is equipped with the inclination small diameter part 25 and the thick part 24 following it. An inclined tip surface 21 is formed at the tip of the inclined small diameter portion 25. In addition, the outer diameter of the outer tube main body portion on the proximal end side from the inclined small diameter portion of the outer tube 2 is substantially the same as the outer diameter of the cylindrical portion 43 and the rear end portion of the balloon 4. The inclined small-diameter portion 25 of the outer tube 2 is inserted and fixed in the inclined rear end portion of the balloon 4 to form the inclined annular fixing portion 6b. In the balloon catheter 20, the rear end side of the expandable portion 41 of the balloon 4 extends to the rear end portion of the outer tube 2 with substantially the same outer diameter. And also in this catheter 20, there is no level | step difference in the junction end of the balloon 4 exposed to the outer surface, and the outer tube | pipe 2. FIG.
In addition, like the balloon catheter 30 shown in FIG. 12, the outer tube 2 may have an entire inner diameter extending to the rear end portion with the inner diameter of the inclined small diameter portion 25. Also in the balloon catheter 30 of this embodiment, the inclined distal end portion of the outer tube 2 is inserted into the inclined rear end portion of the balloon 4 and fixed, thereby forming the inclined annular fixing portion 6c.

Further, the joining form of the rear end portion of the balloon 4 and the distal end portion of the outer tube 2 may be of the type provided in the balloon catheter 40 of the embodiment shown in FIGS. 13 and 14.
In the balloon catheter 40 of this embodiment, the rear end portion of the balloon 4 is not an inclined diameter-expanded portion, and is formed by extending the tubular portion 43 as it is and terminating obliquely. The outer tube 2 extends to the rear end with an outer diameter that can be inserted into the rear end of the balloon 4. Then, the inclined tip end portion of the outer tube 2 is inserted into the inclined rear end portion of the balloon 4 and fixed, thereby forming the inclined annular fixing portion 6d. In this balloon catheter 40, the inclined annular fixing portion 6d has an inclined step, but the outer diameter of the outer tube 2 is small.

Further, the joining form of the rear end portion of the balloon 4 and the distal end portion of the outer tube 2 may be of the type provided in the balloon catheter 50 of the embodiment shown in FIGS. 15 and 16.
In the balloon catheters of all the embodiments described above, the distal end portion of the outer tube 2 is inserted into the rear end portion of the balloon 4, but in the balloon catheter 50 of this embodiment, the outer tube is conversely arranged. The inclined rear end portion of the balloon 4 is inserted into the two inclined front end portions, and this insertion portion forms a portion where the front end portion of the outer tube 2 and the rear end portion 44 of the balloon 4 overlap. And the inclined annular fixing | fixed part 6e is formed by fixing this overlapping part. And the outer edge of the inclined front end surface of the outer tube 2 is rounded with no edges.
Also in the balloon catheter 50 of this embodiment, the distal end portion of the outer tube 2 includes an inclined distal end surface 21 that is inclined with respect to the central axis of the outer tube 2, and the balloon 4 has a tubular portion 43 at the rear end portion 44. An inclined rear end face 45 that is inclined with respect to the central axis is provided. And the front-end | tip part of the outer tube | pipe 2 and the rear-end part 44 of the balloon 4 are being fixed with the belt-shaped inclined cyclic | annular fixing | fixed part 6e inclined with respect to the center axis | shaft of the outer tube | pipe 2 and airtightly formed. Since the cylindrical portion 43 and the rear end portion 44 of the balloon 4 are higher in flexibility and flexibility than the distal end portion of the outer tube 2, the inclined annular fixing portion 6e is formed from the rear end side to the front end portion. Flexibility toward the side increases. Therefore, a sharp property change point in the vicinity of the distal end portion of the outer tube 2 is not formed, preventing the occurrence of kinks and maintaining good deformability. The outer diameter of the outer tube 2 is substantially the same as the outer diameter of the cylindrical portion 43 of the balloon 4, and the catheter 50 is expanded in diameter at the outer tube portion.

Also in the balloon catheter 50 of this embodiment, as shown in FIG. 17, the inclined rear end surface 45 of the balloon 4 and the inclined front end surface 21 of the outer tube 2 are substantially parallel or have different inclination angles with respect to the central axis of the outer tube. However, it is 44 degrees or less, preferably 20 degrees or less. As shown in FIG. 17, an inclination angle C with respect to the central axis of the cylindrical portion 43 (outer tube 2) of the inclined rear end surface 45 of the balloon 4, relative to the central axis of the outer tube 2 of the inclined distal end surface 21 of the outer tube 2. It is preferable that the inclination angle D is large. The inclination angle C of the inclined rear end face 45 of the balloon 4 with respect to the central axis of the tubular portion 43 (outer tube 2) is preferably 35 degrees to 65 degrees, and particularly preferably 40 degrees to 50 degrees. In addition, the inclination angle D of the inclined distal end surface 21 of the outer tube 2 with respect to the central axis of the outer tube 2 is preferably 15 degrees to 35 degrees, and more preferably 20 degrees to 30 degrees.
The rear end portion of the balloon 4 that has entered the front end portion of the outer tube 2 is airtightly fixed to the outer tube 2 and forms a belt-like inclined annular fixing portion 6e. The inclined annular fixing part 6 e has an annular fixing surface 61. The annular fixing portion 61 is formed on the entire inner surface of the base end portion 44 of the balloon 4 that contacts the outer surface of the distal end portion of the outer tube 2 of the inclined annular fixing portion 6e.

It is preferable that the annular fixing portion 61 has substantially the same width or gradually becomes wider toward the rear end. In the balloon catheter 50 of this embodiment, as shown in FIG. 17, the annular fixing portion 61 is gradually widened toward the rear end. Also in the balloon catheter 50 of this embodiment, as shown in FIG. 17, the phantom line connecting the tip 22 of the inclined front end surface 21 of the outer tube 2 and the tip 46 of the inclined rear end surface 45 of the balloon 4 is 2 is almost parallel to the central axis. In other words, the distal end 22 of the inclined distal end surface 21 of the outer tube 2 is positioned substantially in front of the distal end 46 of the inclined rear end surface 45 of the balloon 4. Similarly, an imaginary line connecting the rear end 23 of the inclined distal end surface 21 of the outer tube 2 and the rear end 47 of the inclined rear end surface 46 of the balloon 4 is substantially parallel to the central axis of the outer tube 2. That is, the rear end 23 of the inclined front end surface 21 of the outer tube 2 is positioned substantially in front of the rear end 47 of the rear end surface 45 of the balloon 4 in the front end direction. For this reason, a narrow portion is not formed in the annular fixing portion 61.

Furthermore, in this embodiment, the tip 46 of the inclined rear end surface 45 of the balloon 4 is located on the front end side from the rear end 23 of the inclined front end surface 21 of the outer tube 2. The rear end 23 of the inclined front end surface 21 of the outer tube 2 and the front end 46 of the inclined rear end surface 45 of the balloon 4 may be located at the same position in the axial direction of the outer tube 2. For this reason, the physical property of the inclined annular fixing portion 6e continuously changes. Since the cylindrical portion 43 and the rear end portion 44 of the balloon 4 are higher in flexibility and flexibility than the distal end portion of the outer tube 2, the inclined annular fixing portion 6e is formed from the rear end side to the front end portion. Flexibility and softness gradually increase toward the side. In particular, in the inclined annular fixing portion 6e of this embodiment, the portion where the distal end portion of the outer tube 2 covers the rear end portion of the balloon 4 increases from the rear end side, and the rear end of the inclined distal end surface 21 of the outer tube 2 increases. Beyond the end 23, the rear end portion 44 of the balloon 4 continues to increase in cross-sectional area perpendicular to the axial direction, but decreases in cross-sectional area perpendicular to the axial direction of the distal end portion of the outer tube 2. And in the front-end | tip 46 of the inclined surface 45 of the rear-end part 44 of the balloon 4, the cross section of the rear-end part 44 becomes cyclic | annular, Furthermore, the front-end | tip part of the outer tube 2 reduces the cross-sectional area in the front, Terminate at the tip 22. In other words, in this embodiment, the inclined annular fixing portion 6e is entirely annular on the cut surface perpendicular to the central axis of the outer tube 2 so that the rear end portion 44 of the balloon 4 and the distal end portion of the outer tube 2 are both annular. It is something that has no part.

The distance S between the distal end 22 of the outer tube 2 and the distal end 46 of the inclined rear end face 45 of the balloon 4 in FIG. 17 is preferably 0.5 to 7.0 mm, particularly 0.6 to 1.0 mm. It is preferable that The distance T between the rear end 23 of the inclined front end surface 21 of the outer tube 2 and the rear end 47 of the inclined rear end surface 45 of the balloon 4 is preferably 0.5 to 2.5 mm, particularly 0.65. It is preferably ˜1.00 mm. The axial length Q of the inclined annular fixing portion 6e (in other words, the distance between the distal end 22 of the outer tube 2 and the rear end 47 of the inclined rear end face 45 of the balloon 4) is 2.0 to 11.6 mm. In particular, the thickness is preferably 2.2 to 3.5 mm. Further, the distance R between the rear end 23 of the inclined front end face 21 of the outer tube 2 and the front end 46 of the inclined rear end face 45 of the balloon 4 is preferably 0.7 to 2.1 mm, particularly 0.9 to It is preferable that it is 1.5 mm.

As shown in FIG. 4, the branch hub 5 includes a first opening 54 that communicates with the first lumen 11, an inner tube hub 52 fixed to the rear end portion of the inner tube 3, and a second The outer tube hub 51 and the inner tube hub 52 are provided with an outer tube hub 51 that has a second opening 55 that communicates with the lumen 12 and forms an injection port 53 and is fixed to the rear end of the outer tube 2. , Has been fixed. The outer tube hub 51 and the inner tube hub 52 are fixed by inserting and joining the inner tube 3 from the rear end of the outer tube hub 51 attached to the base end portion of the outer tube 2. Further, the branch hub 5 is provided with a bending prevention tube 56 that encloses the proximal end portion of the outer tube 2 and the distal end portion of the branch hub 5. The injection port 53 is formed by a branch port 53a extending from the side wall of the outer pipe hub 51, an injection port hub 53b, and a connection tube 53c that connects the branch port 53a and the injection port hub 53b. As a material for forming the branch hub, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be preferably used. As the connection tube, a flexible or soft synthetic resin tube is used.

The structure of the balloon catheter is not limited to the one described above, and has a guide wire insertion port that communicates with the guide wire lumen in the middle portion of the balloon catheter (the rear end side from the inclined annular fixing portion 6). It may be a thing.
The balloon catheter of the present invention is preferably applied to a catheter for drug administration with a vascular occlusion function, but is not limited thereto, and can be applied to a PTCA catheter, a balloon expandable stent delivery system, and the like. it can.

The balloon catheter of the present invention is as follows.
(1) An inner tube having a first lumen, and provided coaxially with the inner tube, having a tip at a position retracted by a predetermined length from the tip of the inner tube, and between the outer surface of the inner tube An outer tube forming two lumens, an expandable balloon having a distal end fixed to the inner tube, a rear end fixed to the distal end of the outer tube, and an interior communicating with the second lumen. The balloon catheter includes an expandable portion formed on the rear end side of the tip portion, and formed between the expandable portion and the rear end portion, and has a predetermined length in the rear end direction. And the rear end portion includes an inclined rear end surface that is inclined with respect to the central axis of the cylindrical portion, and the front end portion of the outer tube is formed of the outer tube. An inclined distal end surface that is inclined with respect to a central axis, and the distal end portion of the outer tube and the balloon The rear end portion of the balloon catheter has a portion overlapping in the axial direction of the balloon catheter, and the distal end portion of the outer tube and the rear end portion of the balloon are provided in the overlapping portion, A balloon catheter which is fixed by a belt-like inclined annular fixing portion which is inclined with respect to the central axis and is formed airtight.
In the above balloon catheter, since the balloon has a cylindrical portion extending in the predetermined long axis direction between the expandable portion and the rear end portion, the distal end side of the outer tube is made low profile (the diameter is reduced when inserted into the living body). This makes it easy to insert into a smaller body cavity (for example, a blood vessel), and the physical properties of the fixed part between the rear end of the balloon and the distal end of the outer tube change gradually. A portion where the physical properties change suddenly near the distal end of the tube and near the proximal end of the balloon is not formed, and kinks due to the change in physical properties are less likely to occur, and the insertion into the body cavity is easy.

And as an embodiment of the present invention, the following may be sufficient.
(2) The balloon catheter according to (1), wherein a portion overlapping in the axial direction of the balloon catheter is formed by entering the distal end portion of the outer tube into the rear end portion of the balloon.
(3) In the above (1) or (2), the inclined rear end surface of the balloon and the inclined front end surface of the outer tube are substantially parallel or have a difference in inclination angle with respect to the central axis of the outer tube of 44 degrees or less. The balloon catheter described.
(4) The inclination angle of the inclined front end surface of the outer tube with respect to the central axis of the outer tube is larger than the inclination angle of the inclined rear end surface of the balloon with respect to the central axis of the outer tube. Thru | or the balloon catheter in any one of (3).
(5) The balloon catheter according to any one of (1) to (4), wherein the inclined annular fixing portion has substantially the same width or gradually becomes wider toward the rear end.
(6) The imaginary line connecting the tip of the inclined front end surface of the outer tube and the tip of the inclined rear end surface of the balloon is substantially parallel to the central axis of the outer tube (1) to (5) The balloon catheter according to any one of the above.
(7) The imaginary line connecting the rear end of the inclined front end surface of the outer tube and the rear end of the inclined rear end surface of the balloon is substantially parallel to the central axis of the outer tube. (6) The balloon catheter according to any one of the above.
(8) The tip of the inclined rear end surface of the balloon is located at the same position in the axial direction as the rear end of the inclined distal end surface of the outer tube or the tip end side in the axial direction (1) to (7) The balloon catheter according to any one of the above.
(9) Any of (1) to (8) above, wherein the balloon catheter includes a first opening communicating with the first lumen and a second opening communicating with the second lumen. The balloon catheter according to 1.
(10) The balloon catheter includes a hub fixed to proximal ends of the inner tube and the outer tube, and the hub includes the first opening and the second opening. The balloon catheter according to).

Claims

An inner tube having a first lumen and a second lumen provided coaxially with the inner tube, having a tip at a position retracted by a predetermined length from the tip of the inner tube, and the outer surface of the inner tube A balloon catheter comprising: an outer tube having a distal end fixed to the inner tube; a rear end fixed to the distal end of the outer tube; and an expandable balloon having an interior communicating with the second lumen Because
The balloon includes an expandable part formed on the rear end side from the tip part, and a cylindrical part formed between the expandable part and the rear end part and extending a predetermined length in the rear end part direction. And the rear end portion includes an inclined rear end surface that is inclined with respect to the central axis of the cylindrical portion,
The distal end portion of the outer tube includes an inclined distal end surface that is inclined with respect to the central axis of the outer tube,
The distal end portion of the outer tube and the rear end portion of the balloon have a portion overlapping in the axial direction of the balloon catheter, and the distal end portion of the outer tube and the rear end portion of the balloon are A balloon catheter characterized in that it is fixed by a belt-like inclined annular fixing portion provided in an overlapping portion, inclined with respect to the central axis of the outer tube and formed in an airtight manner.
The balloon catheter according to claim 1, wherein a portion overlapping in the axial direction of the balloon catheter is formed by the distal end portion of the outer tube entering the rear end portion of the balloon.
The balloon catheter according to claim 1 or 2, wherein the inclined rear end surface of the balloon and the inclined front end surface of the outer tube are substantially parallel or have a difference in inclination angle of 44 degrees or less with respect to the central axis of the outer tube.
The inclination angle of the inclined front end surface of the outer tube with respect to the central axis of the outer tube is larger than the inclination angle of the inclined rear end surface of the balloon with respect to the central axis of the outer tube. A balloon catheter according to claim 1.
The balloon catheter according to any one of claims 1 to 4, wherein the inclined annular fixing portion has substantially the same width or gradually becomes wider toward the rear end.
6. The imaginary line connecting the tip of the inclined front end surface of the outer tube and the tip of the inclined rear end surface of the balloon is substantially parallel to the central axis of the outer tube. Balloon catheter.
The imaginary line that connects the rear end of the inclined front end surface of the outer tube and the rear end of the inclined rear end surface of the balloon is substantially parallel to the central axis of the outer tube. The balloon catheter according to 1.
The tip of the inclined rear end surface of the balloon is located at the same position as the rear end of the inclined tip surface of the outer tube in the axial direction or at the distal end side in the axial direction. Balloon catheter.
The balloon catheter according to any one of claims 1 to 8, wherein the balloon catheter includes a first opening communicating with the first lumen and a second opening communicating with the second lumen.
The balloon catheter includes a hub fixed to proximal ends of the inner tube and the outer tube, and the hub includes the first opening and the second opening. Balloon catheter.