JP6847567B2 - Balloon catheter - Google Patents

Description

The present invention relates to a balloon catheter used for the treatment of aneurysms.

In recent years, stent-graft interpolation has attracted attention as a treatment method for aortic aneurysm.
In stent graft insertion, indwelling stent grafts are usually crimped with an occlusion balloon catheter for the purpose of avoiding end leaks, and a balloon divided into three lobes is provided as such a balloon catheter. A Tri-Love balloon catheter has been introduced (see Non-Patent Document 1 below).
According to this Tri-Love balloon catheter, it is said that a part of blood flow to the periphery can be maintained even when the balloon is dilated in the aorta.

However, the blood flow that can be secured from the gaps between the three balloons constituting the Tri-Love balloon catheter is not sufficient.
Further, the expanding force of these balloons is not sufficient for crimping the stent graft, and the crimping force of the three balloons on the stent graft varies in the circumferential direction.

On the other hand, in Patent Document 1 below, a bag-like object having elasticity is attached to the tip portion of the catheter, and when the bag-like object does not accept a fluid inside, a flattened film-like object is provided. A dissecting aortic aneurysm treatment tool has been proposed, which is tubular when a fluid is received and in which the inner and outer membranes that make up this bag are partially joined. ing.
According to this treatment tool, since the bag-shaped object (balloon) when the fluid is received inside becomes tubular, it is possible to sufficiently secure the blood flow to the periphery.

However, even in the treatment tool described in Patent Document 1, it cannot be said that the expanding force due to the bag-shaped object (substantially cylindrical balloon) when the fluid is received is sufficient.
Further, in the treatment tool described in Patent Document 1, as shown in FIG. 16, the proximal edge 2a of the bag-shaped object 2 (balloon) after contraction is perpendicular to the axial direction of the catheter 1 (catheter shaft). Therefore, when the bag-shaped object 2 is pulled back to the lumen of the guiding catheter or the like by being wrapped around the catheter 1, the base end of the bag-shaped object 2 is easily caught in the opening of the guiding catheter, and the bag-shaped object is easily caught. There is also a problem that the pull-back operation of 2 is difficult.

Stent Graft Interpolation for Chest Aneurysm: Indications and Procedures Artificial Organ Vol. 38, No. 1, 2009

Japanese Unexamined Patent Publication No. 2001-61968

The present invention has been made based on the above circumstances.
An object of the present invention is to ensure sufficient blood flow to the periphery when the balloon is expanded in the aneurysm, and to pull the balloon in the contracted state back to a lumen such as a guiding catheter. The purpose is to provide a balloon catheter capable of smoothly performing the above.
Another object of the present invention is to provide a balloon catheter having a high degree of roundness in the cross section and capable of uniformly expressing a high diastolic pressure in the circumferential direction.

(1) The balloon catheter of the present invention has a catheter shaft having a lumen for circulating a fluid (hereinafter, referred to as "expansion lumen"), a hub connected to the proximal end side of the catheter shaft, and the catheter. It is equipped with a tubular balloon connected to the tip side of the shaft.
The tip of the catheter shaft is inserted into the lumen of the balloon while being in contact with the inside of the tube wall of the balloon or the inner peripheral surface of the balloon.
The central axis of the catheter shaft is twisted with the tube axis of the balloon, and the angle formed with the tube axis is 45 ° or less.

Here, the "balloon tube wall" refers to a portion surrounding the lumen of the balloon, and includes a space sandwiched between the outer peripheral surface and the inner peripheral surface of the balloon (for example, the inside of a convex portion described later).

(2) In the balloon catheter of the present invention, the angle formed by the central axis of the catheter shaft and the tube axis of the balloon is preferably 15 to 30 °.

Here, the angle formed by the central axis of the catheter shaft and the tube axis of the balloon means the angle formed by the vector extending in the tip direction on the central axis and the vector extending in the tip direction on the tube axis.

According to the balloon catheter having the above configuration, since the balloon constituting the balloon is tubular, the stent graft placed in the aneurysm can be crimped to the inner wall surface of the aneurysm, and the blood flow to the periphery can be increased. It can be secured sufficiently.
Further, the tip of the catheter shaft is inserted into the lumen of the balloon while being in contact with the inside of the tube wall of the balloon or the inner peripheral surface of the balloon, and the central axis of the catheter shaft and the tube axis of the balloon are aligned with each other. By being in a twisted positional relationship (not in a parallel positional relationship), the base end edge of the contracted balloon can be tilted with respect to the virtual plane perpendicular to the central axis of the catheter shaft. When pulling this balloon back to the lumen of a guiding catheter or the like by wrapping it around the catheter shaft, the base end of the balloon does not get caught in the opening of the guiding catheter or the like, and the pulling back operation of the balloon can be performed smoothly. it can.

(3) In the balloon catheter of the present invention, it is preferable that the balloon has a smooth outer peripheral surface.
According to the balloon catheter having such a configuration, the stent graft placed in the aneurysm can be fitted to the inner wall surface of the aneurysm and crimped reliably.

(4) In the balloon catheter of the present invention, on the inner circumference of the balloon, convex portions having the same shape as each other, which are formed so as to incline and extend in the direction of the tube axis and can accommodate a fluid inside, have a circumference. At least four are placed along the direction,
The insides of the convex parts communicate with each other,
When the fluid supplied from the expansion lumen of the catheter shaft flows into the inside, each of the convex portions expands, and the adjacent convex portions come into contact with each other and press against each other. It is preferable that the balloon expands.
Here, the number of convex portions arranged on the inner circumference of the balloon is preferably 6 to 12, and particularly preferably 8.
According to the balloon catheter having such a configuration, each of the convex portions arranged along the circumferential direction on the inner circumference of the balloon expands and presses against each other to expand the balloon, so that the balloon expands. Has a high degree of roundness in the cross section, and can uniformly express an expansion pressure higher than that of a balloon constituting a conventionally known balloon catheter in the circumferential direction.

(5) In the balloon catheter of the above (4), it is preferable that the catheter shaft is composed of an inner tube having a guide wire lumen and an outer tube forming the expansion lumen together with the inner tube.

(6) In the balloon catheter of the above (5), the tip end portion of the catheter shaft is inserted into the inside of any one of the convex portions (inside the tube wall of the balloon), and the expansion is made inside the convex portion. It is preferable that the fluid flowing through the lumen is supplied.

According to the balloon catheter having such a configuration, the fluid flowing through the expansion lumen is supplied to the inside of the convex portion through which the tip portion of the catheter shaft is inserted through the side hole formed in the tube wall of the outer tube. Further, the fluid can be supplied to the inside of the other convex portion communicating with the convex portion.

(7) Further, in the balloon catheter of the above (5), the tip end portion of the catheter shaft is inserted into the lumen of the balloon while contacting the convex surface of any one of the convex portions, and the inside of the convex portion is inserted. May be supplied with a fluid flowing through the expansion lumen.

According to the balloon catheter having such a configuration, the fluid flowing through the expansion lumen is passed through the communication hole that communicates the expansion lumen with the inside of the convex portion, and the inside of the convex portion where the tip of the outer tube is in contact with the fluid. And further, the fluid can be supplied to the inside of other convex parts communicating with this convex part.

(8) In the balloon catheter of the above (4), it is preferable that the convex surface of the convex portion is formed substantially flat.

According to the balloon catheter having such a configuration, the blood flow to the periphery can be further secured, and the force when each of the convex portions expands and pushes against each other, and by extension, the expanding force of the balloon. Can be increased.

(9) In the balloon catheter of the above (4), a tip convex portion having a height lower than that of the convex portion, which can accommodate a fluid inside, is formed in the inner circumference of the tip portion of the balloon along the circumferential direction. The inside of the tip convex portion is formed so as to extend, and communicates with each inside of the convex portion via a narrow flow path.
The inner circumference of the rear end portion of the balloon is formed so that a rear end convex portion having a height lower than that of the convex portion extends along the circumferential direction so as to be able to accommodate a fluid inside, and the rear end convex portion is formed. The inside of the portion communicates with the inside of each of the convex portions via a narrow flow path.
It is preferable that the insides of the convex portions communicate with each other.

According to the balloon catheter having such a configuration, the tip convex portion and the rear end convex portion, which are lower in height than the convex portion, are formed so as to extend along the circumferential direction, whereby the tip portion and the rear end portion of the balloon are formed. The balloon can be expanded without the end portion being deformed or overinflated, and the roundness of the cross section at the front end portion and the rear end portion of the balloon at the time of expansion is also high.

(10) The balloon catheter of the present invention is suitably used for the treatment of aneurysms by stent graft interpolation.

According to the balloon catheter of the present invention, when the balloon constituting the balloon is expanded in the aneurysm, sufficient blood flow to the periphery can be secured, and the balloon in the contracted state can be used as a guiding catheter. The operation of pulling back to the lumen can be performed smoothly.
Further, according to the balloon catheter of the above (3), the roundness of the cross section is high, and a high diastolic pressure can be uniformly expressed in the circumferential direction.

It is a front view of the balloon catheter which concerns on 1st Embodiment of this invention. It is a top view of the balloon catheter shown in FIG. FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 1 is a sectional view taken along line IV-IV of FIG. FIG. 5 is a sectional view taken along line VV of FIG. It is a figure which shows the state which expanded the balloon in the balloon catheter shown in FIG. In the balloon catheter shown in FIG. 1, it is a cross section showing a state in which each of the convex portions of the balloon is expanded by the inflow of fluid. It is explanatory drawing which shows typically the shape of the balloon in a contracted state which is pulled back to the lumen of a guiding catheter in the balloon catheter shown in FIG. It is a front view of the balloon catheter which concerns on 2nd Embodiment of this invention. It is a top view of the balloon catheter shown in FIG. FIG. 9 is a cross-sectional view taken along the line XI-XI of FIG. 9 is a cross-sectional view taken along the line XII-XII of FIG. 9 is a cross-sectional view taken along the line XIII-XIII of FIG. It is a figure which shows the state which expanded the balloon in the balloon catheter shown in FIG. It is explanatory drawing which shows the modification of the balloon catheter which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the connection state of a catheter shaft and a balloon in a conventional balloon catheter.

<First Embodiment>
The balloon catheter 100 of the present embodiment shown in FIGS. 1 to 8 is used for stent graft interpolation which is a treatment method for aortic aneurysm.
The balloon catheter 100 includes a catheter shaft 10, a hub 20 connected to the proximal end side of the catheter shaft 10, and a tubular balloon 30 connected to the distal end side of the catheter shaft 10 and having a smooth outer peripheral surface. The tip of the catheter shaft 10 is inserted into the tube wall of the balloon 30 (inside the convex portion 334 described later), and the central axis 10A of the catheter shaft 10 and the tube axis 30A of the balloon 30 are in a twisted positional relationship. is there.

As shown in FIGS. 3 to 5, the catheter shaft 10 constituting the balloon catheter 100 is a shaft having a double tube structure including an inner tube 11 and an outer tube 13.

As shown in FIG. 3, a guide wire lumen 12 for inserting a guide wire is formed in the inner tube 11.
Further, an expansion lumen 14 for flowing a fluid is formed by the outer peripheral surface of the inner tube 11 and the inner peripheral surface of the outer tube 13.

A side hole 19 is formed at the tip of the catheter shaft 10 so as to penetrate the tube wall of the outer tube 13 and open to the outer peripheral surface, and the fluid flowing through the expansion lumen 14 passes through the side hole 19. It is discharged to the outside of the catheter shaft 10.
Here, physiological saline can be exemplified as the fluid.

The inner diameter of the inner tube 11 is preferably 0.5 to 1.1 mm, and a suitable example is 0.95 mm.
The outer diameter of the inner tube 11 is preferably 0.7 to 1.3 mm, and a suitable example is 1.15 mm.
Suitable materials constituting the inner tube 11 include PEEK, PEBAX, polyurethane, nylon and the like.

The inner diameter of the outer tube 13 is preferably 0.8 to 3.8 mm, and a suitable example is 1.8 mm.
The outer diameter of the outer tube 13 (outer diameter of the catheter shaft 10) is preferably 2 to 5 mm, and a suitable example is 3 mm.
Suitable materials constituting the outer tube 13 include PEBAX, polyurethane, nylon and the like.

A hub 20 is connected to the proximal end side of the catheter shaft 10.
The hub 20 constituting the balloon catheter 100 is provided with a guide wire port 22 which is an opening of the guide wire lumen 12 of the catheter shaft 10 and an inflation port 24 which is an opening of the expansion lumen 14.

A balloon 30 is connected to the distal end side of the catheter shaft 10.
The balloon 30 constituting the balloon catheter 100 is a tubular balloon having a smooth outer peripheral surface without unevenness, and by expanding the balloon 30, the stent graft placed in the aneurysm is crimped to the inner wall surface of the aneurysm. At the same time, sufficient blood flow to the periphery can be secured.

As shown in FIG. 3, the outer circumference of the balloon 30 is formed by a smooth surface without unevenness. As a result, the stent graft crimped by the balloon 30 can be adapted to the inner wall surface of the aneurysm.
Here, the outer diameter of the balloon 30 is preferably 20 to 40 mm, and a suitable example is 32 mm.

As shown in FIGS. 3 and 6, on the inner circumference of the balloon 30, convex portions 331 to 338 having the same shape as each other, which are formed so as to extend in a direction inclined by 30 ° with respect to the tube axis direction, are circumferential. They are arranged at 45 ° intervals along the direction.

The protrusions 331 to 338 are so-called small balloons that expand by accommodating a fluid inside each of them.
Each convex surface of the convex portions 331 to 338 is formed to be substantially flat. As a result, the blood flow to the periphery when the balloon 30 is expanded can be increased more than the convex portion having a curved convex surface (kamaboko-shaped convex portion), and each of the convex portions 331 to 338 can be increased. The force when expanding and pushing against each other, and by extension, the expanding force of the balloon 30 can be increased.

In the formed portion of the convex portions 331 to 338, the film thickness (t ₁ ) on the outer peripheral side of the balloon 30 is preferably 50 to 180 μm, and a suitable example is 120 μm.
When the film thickness (t ₁ ) on the outer peripheral side is too small, the outer circumference of the balloon at the time of expansion is partially overinflated, impairing the roundness of the cross section, and a uniform expansion force in the circumferential direction. May not be able to be expressed. On the other hand, when this film thickness (t ₁ ) is excessive, it may be difficult to process the balloon into a tubular shape, or the balloon may not be sufficiently expanded.

_{The film thickness (t 2} ) on the inner peripheral side of the balloon 30 is preferably 50 to 180 μm, and a suitable example is 120 μm.
When the film thickness (t ₂ ) on the inner circumference side is too small, the inner circumference of the balloon at the time of expansion is partially overinflated, the roundness of the cross section is impaired, and the balloon is uniform in the circumferential direction. It may not be possible to develop diastolic power. On the other hand, when this film thickness (t ₂ ) is excessive, it becomes difficult to process the balloon into a tubular shape, or the expansion of the convex portion is suppressed, so that the balloon can be sufficiently expanded. It may not be there.

The ratio (t ₁ / t _{2 ) of the film thickness (t 1} ) on the outer peripheral side and the film thickness (t ₂ ) on the inner peripheral side in the formed portion of the convex portions 331 to 338 is 0.1 to 3.0. A suitable example is preferably 1.0.
When this ratio (t ₁ / t ₂ ) is 0.1 or more, a higher expansion pressure (compression resistance) can be uniformly expressed in the circumferential direction.
Further, when the ratio (t ₁ / t ₂ ) is 3.0 or less, it is possible to prevent overexpansion in the inner circumference.

As shown in FIGS. 4 and 6, a tip convex portion 31 having a height lower than that of the convex portions 331-338 is formed on the inner circumference of the tip portion of the balloon 30 (the tip side of the formation position of the convex portions 331-338). It is formed so as to extend along the circumferential direction.
The tip convex portion 31 can accommodate a fluid inside thereof, and expands when the fluid flows in. The inside of the tip convex portion 31 communicates with each of the convex portions 331 to 338 via a narrow flow path 321 to 328.

As shown in FIGS. 5 and 6, the inner circumference of the rear end portion of the balloon 30 (the rear end side of the formation position of the convex portions 331-338) is lower in height than the convex portions 331-338 (tip convex). The rear end convex portion 35 (at the same height as the portion 31) is formed so as to extend along the circumferential direction.
The rear end convex portion 35 can accommodate a fluid inside the convex portion 35, and expands when the fluid flows in. The inside of the rear end convex portion 35 communicates with each of the convex portions 331 to 338 via a narrow flow path 341 to 348.
As a result, the insides of the convex portions 331 to 338 communicate with each other with the tip convex portion 31 as the communication flow path on the front end side and the rear end convex portion 35 as the communication flow path on the rear end side.

According to such a structure, the balloon 30 can be expanded without deformation or overexpansion at the tip and the rear end of the balloon 30, and the true on the tip side and the rear end of the balloon 30 at the time of expansion. The degree of yen will also be high.

As the constituent material of the balloon 30, the same resin material as the balloon constituting the conventionally known balloon catheter can be used, and polyurethane can be mentioned as a suitable material.

As shown in FIGS. 3 and 6, the tip of the catheter shaft 10 is inserted into the convex portion 334 forming the tube wall of the balloon 30.
The tip of the catheter shaft 10 is completely sealed at the tip and back of the balloon 30 by the constituent material of the balloon 30, whereby the interior of the convex 334 is airtight and liquidtight. It is secured.

As a result, the fluid that flows through the expansion lumen 14 of the catheter shaft 10 and is discharged to the outside through the side hole 19 formed in the tube wall of the outer tube 13 is a convex through which the tip end portion of the catheter shaft 10 is inserted. It is supplied to the inside of the portion 334 (inside the tube wall of the balloon 30).
Next, the fluid that has flowed into the convex portion 334 flows into the other convex portions (convex portions 331 to 333 and 335 to 338) through the front end convex portion 31 or the rear end convex portion 35.

The balloon 30 is shown in FIG. 6 in which a smooth first resin sheet and a second resin sheet formed into an inner peripheral side shape after completion (a region in which a convex portion of the sheet is not formed) are bonded together. Such a laminated sheet having a fluid accommodating space is produced, and both sides of the obtained laminated sheet are laminated so that the first resin sheet is located on the outer peripheral side and processed into a tubular shape. can do.
When the first resin sheet and the second resin sheet are attached to each other, the tip end portion of the catheter shaft 10 is positioned inside the convex portion 334 formed.

In the balloon catheter 100 of this embodiment, fluid flows in from the expansion lumen 14 of the catheter shaft 10 and each of the convex portions 331 to 338 expands, so that the adjacent convex portions come into contact with each other and press each other. As a result, a strong expanding force that tries to expand the balloon 30 in its radial direction is exhibited.

FIG. 7 is a cross-sectional view of the balloon 30 showing a state in which each of the convex portions 331 to 338 is expanded by the inflow of the fluid, and FIG. 7A is a state before the fluid flows into the convex portions 331 to 338. , (B) is a state in which the fluid flows into each of the insides and the convex portions 331 to 338 are expanded, but the adjacent convex portions are not in contact with each other, and in (C), the convex portions 331 to 338 are in contact with each other. Further expanded, it is a state in which adjacent convex portions are in contact with each other and press against each other.

In FIGS. 7A to 7C, the convex portions 331 to 338 are expanded in a state where the balloon 30 is housed in a tube (a tube simulating a blood vessel) (not shown) that suppresses the expansion of the balloon 30. Although the outer diameter of the balloon 30 has not changed, the pressing force (expansion pressure) on the inner peripheral surface of the tube is shown in FIGS. (A) <(B) <(C).

As described above, the balloon 30 which expands by pressing the convex portions formed on the inner circumference of the balloon 30 against each other has a high degree of roundness of the cross section at the time of expansion (the shape is close to a true cylinder). Also, the expanding power expressed is sufficiently high and uniform.
It is considered that the reason is that the forces that stick to each other act to make it less likely to be distorted by the pressure from the outside, and the convex portions having the same shape are used to expand evenly.

According to the balloon catheter 100 of the present embodiment, when the balloon 30 is expanded in the aneurysm and the stent graft is crimped to the inner wall of the aneurysm, sufficient blood flow to the periphery can be sufficiently secured, and at the time of expansion. In the balloon 30, the roundness of the cross section is high, a high expansion pressure can be uniformly expressed in the circumferential direction, and the indwelling stent graft can be reliably crimped.

Further, since the tip end portion of the catheter shaft 10 is inserted into the inside of the convex portion 334 extending in the direction inclined with respect to the tube axis direction of the balloon 30, the central axis 10A of the catheter shaft 10 and the tube of the balloon 30 are inserted. The shaft 30A has a twisting positional relationship, and the angle formed by the two is 30 ° (corresponding to the inclination angle of the convex portion 334 with respect to the tube axis direction of the balloon 30).

As a result, as shown in FIG. 8A, the proximal edge 38 of the flat balloon 30 after contraction is tilted with respect to the virtual plane P perpendicular to the central axis 10A of the catheter shaft 10 (tilt angle θ). ≈30 °), and as shown in FIG. 8B, when the balloon 30 is pulled back to the lumen of the guiding catheter 50 while being wound around the catheter shaft 10, the balloon is opened in the opening of the guiding catheter 50. The base end of the balloon 30 is not caught, so that the pull-back operation of the balloon 30 can be smoothly performed.

<Second Embodiment>
The balloon catheter 200 of the present embodiment shown in FIGS. 9 to 14 is used for stent graft interpolation which is a treatment method for aortic aneurysm.
9 to 14, the components shown by the same reference numerals as those in FIGS. 1 to 8 are the same components as those in the first embodiment, and the description thereof will be omitted.

The balloon catheter 200 includes a catheter shaft 10, a hub 20 connected to the proximal end side of the catheter shaft 10, and a tubular balloon 30 connected to the distal end side of the catheter shaft 10 and having a smooth outer peripheral surface. The tip of the catheter shaft 10 is inserted into the lumen of the balloon 30 while in contact with the inner peripheral surface of the balloon 30 (the convex surface of the convex portion 334), and the central axis 10A of the catheter shaft 10 and the tube of the balloon 30. The shaft 30A is in a twisted positional relationship.

In the balloon catheter 200, the tip of the catheter shaft 10 is in contact with the inner peripheral surface of the balloon 30 (convex surface of the convex portion 334) instead of the inside of the tube wall of the balloon 30 (convex portion 334 described later). It differs from the balloon catheter 100 of the first embodiment in that it is inserted into the lumen of the first embodiment.

As shown in FIG. 11, the fluid from the expansion lumen 14 flows into the convex portion 334 of the balloon 30 in accordance with the position of the side hole 19 that opens on the outer peripheral surface of the catheter shaft 10 (outer tube 13). A hole 39 is formed to allow the hole 39 to be formed.

As a result, the fluid that flows through the expansion lumen 14 of the catheter shaft 10 and is discharged to the outside of the catheter shaft 10 through the side hole 19 formed in the tube wall of the outer tube 13 passes through the hole 39 and the convex portion 334. It is supplied to the inside of the balloon 30 (inside the tube wall of the balloon 30).
Next, the fluid that has flowed into the convex portion 334 flows into the convex portions 331 to 333 and 335 to 338 through the front end convex portion 31 or the rear end convex portion 35.

According to the balloon catheter 200 of the present embodiment, when the balloon 30 is expanded in the aneurysm and the stent graft is crimped to the inner wall of the aneurysm, sufficient blood flow to the periphery can be sufficiently secured, and at the time of expansion. In the balloon 30, the roundness of the cross section is high, a high expansion pressure can be uniformly expressed in the circumferential direction, and the indwelling stent graft can be reliably crimped.

Further, the tip of the catheter shaft 10 is inserted into the lumen of the balloon 30 while being in contact with the convex surface of the convex portion 334 extending in the direction inclined with respect to the tube axis direction of the balloon 30, so that the catheter shaft 10 is inserted. The central axis 10A of the balloon 30 and the tube axis 30A of the balloon 30 have a twisted positional relationship, and the angle formed by the two is 30 ° (corresponding to the inclination angle of the convex portion 334 with respect to the tube axis direction of the balloon 30).

As a result, the proximal edge of the flat balloon 30 after contraction can be tilted with respect to the virtual plane perpendicular to the central axis 10A of the catheter shaft 10 (tilt angle ≈30 °), and the catheter shaft 10 can be tilted. When the balloon 30 is pulled back to the lumen of the guiding catheter while being wrapped around the balloon 30, the base end of the balloon 30 does not get caught in the opening of the guiding catheter, whereby the pulling back operation of the balloon 30 can be performed smoothly. be able to.

Although one embodiment of the present invention has been described above, the present invention is not limited to these, and various biases are possible.
For example, the number of convex portions arranged inside the balloon is not limited to eight as long as it is four or more. However, since the expanding force tends to decrease as the number of convex portions increases, the number of convex portions is preferably 6 to 12.

Further, the inclination angle of the convex portion with respect to the tube axis direction of the balloon (the angle formed by the central axis of the catheter shaft and the tube axis of the balloon) is not limited to 30 °, but is usually 45 ° or less, preferably 45 ° or less. It is set to 15 to 30 °.
If this inclination angle exceeds 45 °, the base end of the balloon is likely to be caught in the opening of the guiding catheter, and it becomes difficult to smoothly pull back the balloon.

Further, as a modification of the first embodiment, as shown in FIG. 15, the tip portion of the catheter shaft 10 that inserts the inside of the convex portion 334 of the balloon 30 has an intermediate region (a region located inside the convex portion 334). ), A part of the outer tube 13 may be removed and only the inner tube 11 may be formed.

100 Balloon catheter 10 Catheter shaft 10A Central axis of catheter shaft 11 Inner tube 12 Guide wire lumen 13 Outer tube 14 Expansion lumen 19 Side hole 20 Hub 22 Guide wire port 24 Inflation port 30 Balloon 30A Balloon tube shaft 31 Tip convex 321 ~ 328 Narrow flow path 331-338 Convex part 341-348 Narrow flow path 35 Rear end convex part 39 hole 200 Balloon catheter

Claims (10)

It comprises a catheter shaft having lumens for circulating fluid, a hub connected to the proximal end side of the catheter shaft, and a tubular balloon connected to the distal end side of the catheter shaft.
The tip of the catheter shaft is inserted into the lumen of the balloon while being in contact with the inside of the tube wall of the balloon or the inner peripheral surface of the balloon.
A balloon catheter characterized in that the central axis of the catheter shaft is twisted with the tube axis of the balloon and the angle formed with the tube axis is 45 ° or less. The balloon catheter according to claim 1, wherein the angle formed by the central axis of the catheter shaft and the tube axis of the balloon is 15 to 30 °. The balloon catheter according to claim 1 or 2, wherein the balloon has a smooth outer peripheral surface. On the inner circumference of the balloon, at least four convex portions having the same shape, which are formed so as to be inclined with respect to the tube axis direction and can accommodate the fluid, are arranged along the circumferential direction.
The insides of the convex parts communicate with each other,
When the fluid supplied from the lumen of the catheter shaft flows into the inside, each of the convex portions expands, and the adjacent convex portions come into contact with each other and press each other, whereby the balloon is formed. The balloon catheter according to any one of claims 1 to 3, wherein the balloon catheter is expanded. The catheter shaft includes an inner tube having a guide wire lumen and
The balloon catheter according to claim 4, further comprising the inner tube and an outer tube forming the lumen for flowing a fluid. The claim is characterized in that a tip end portion of the catheter shaft is inserted into the inside of any one of the convex portions, and a fluid flowing through the lumen of the catheter shaft is supplied to the inside of the convex portion. 5. The balloon catheter according to 5. The tip of the catheter shaft is inserted into the lumen of the balloon while in contact with any one of the convex surfaces of the convex portion, and a fluid flowing through the lumen of the catheter shaft is supplied to the inside of the convex portion. The balloon catheter according to claim 5, wherein the balloon catheter is made. The balloon catheter according to claim 4, wherein the convex surface of the convex portion is formed substantially flat. A fluid can be accommodated inside the inner circumference of the tip of the balloon, and a tip convex portion having a height lower than that of the convex portion is formed so as to extend along the circumferential direction, and the inside of the tip convex portion is formed. Communicates with the inside of each of the convex portions through a narrow flow path.
The inner circumference of the rear end portion of the balloon is formed so that a rear end convex portion having a height lower than that of the convex portion extends along the circumferential direction so as to be able to accommodate a fluid inside, and the rear end convex portion is formed. The inside of the portion communicates with the inside of each of the convex portions via a narrow flow path.
The balloon catheter according to claim 4, wherein the insides of the convex portions communicate with each other. The balloon catheter according to any one of claims 1 to 9, which is used for treating an aneurysm by stent graft interpolation.

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