WO2014064977A1

WO2014064977A1 - Balloon catheter

Info

Publication number: WO2014064977A1
Application number: PCT/JP2013/069330
Authority: WO
Inventors: 靖洋大川
Original assignee: 日本ライフライン株式会社
Priority date: 2012-10-24
Filing date: 2013-07-16
Publication date: 2014-05-01
Also published as: JP2014083233A; JP6103878B2; CN104755125A; CN104755125B

Abstract

Provided is a double-tube structure balloon catheter, having an outer tube (10), and an inner tube (30), wherein the inner tube (30) is attached to the inner wall of the outer tube (10) at a site away from the rear end of a balloon (20) toward the base end side thereof. With the diameter of the balloon (20) in mm designated D, the length of the balloon (20) in mm designated L, and the distance from the rear end of the balloon (20) to the attachment site of the inner tube (30) in mm designated G, either formula 1A, G≥45(L/D)−292 (where L/D≤8.0), or formula 1B, G≥70(L/D)−495 (where L/D≥8.0), and formula 2, 30≤G≤150, are satisfied. With this balloon catheter, it is possible to alleviate to a degree the relative misalignment between the outer tube and the inner tube, and it is also possible to maintain the linearity of the balloon shape even if high pressure is applied to the interior of the balloon.

Description

Balloon catheter

The present invention relates to a balloon catheter having a double tube structure.

Conventionally, a double-tube balloon catheter having an outer tube and an inner tube is known (see, for example, Patent Document 1 and Patent Document 2).
In the balloon catheter as shown in Patent Document 1 and Patent Document 2, the rear end portion of the balloon is fixed to the front end portion of the outer tube, and the front end portion of the inner tube is fixed to the front end portion of the balloon. The proximal end is open on the side surface of the outer tube.
Here, a fluid for expanding the balloon is passed through the lumen of the outer tube, and a guide wire is inserted through the lumen of the inner tube.

However, in the balloon catheter having such a configuration, since the distal end portion of the outer tube and the distal end portion of the inner tube are connected via the balloon, the inner tube can move freely through the lumen of the outer tube. When the catheter is inserted into the blood vessel, a relative displacement between the outer tube and the inner tube occurs in the longitudinal direction of the catheter. As a result, the operation at the proximal end portion of the catheter by the operator is applied to the distal end portion of the catheter. There is a problem that the catheter cannot reach the target lesion site without being accurately transmitted.

Also, with the relative displacement between the outer tube and inner tube, bellows-like wrinkles are generated and deformed (expanded diameter) in the folded balloon, and the operability of the catheter, particularly the pushability, is remarkable. It may be damaged, making it impossible to penetrate the blood vessel.

To solve such a problem, the inner tube is fixed to the inner wall of the distal end portion of the outer tube fixed to the rear end portion of the balloon without closing the lumen of the outer tube. A technique for preventing relative displacement from the tube has been introduced (see Patent Document 3 and Patent Document 4).

Japanese Patent Laid-Open No. 2002-28243 JP 2003-164528 A Japanese Patent No. 2516453 JP 2008-253421 A

In a double-tube balloon catheter, when a high pressure (for example, rated breaking pressure (RBP)) is applied to the inside of the balloon, the balloon extends in the longitudinal direction of the catheter and the balloon and the outer tube are proximal to the inner tube. Thus, the linearity of the balloon shape can be maintained.

However, in the balloon catheters described in Patent Document 3 and Patent Document 4 described above, the distal end portion of the balloon is fixed to the distal end portion of the inner tube, and the rear end portion of the balloon is connected to the distal end portion of the outer tube. Since it is fixed to the inner tube (that is, both the front and rear ends of the balloon are fixed to the inner tube), when a high pressure is applied to the inside of the balloon, the balloon is restrained by the inner tube. As a result, it cannot be extended in the longitudinal direction of the catheter and is bent into a banana shape. And with such a curved balloon, the expansion force cannot be applied uniformly in the circumferential direction.

Moreover, in the balloon catheter of the said patent document 3, since the rear end part of the balloon which comprises this, the outer tube, the filler for fixing an outer tube and an inner tube, and the inner tube are laminated | stacked. In addition, there is a problem that the balloon catheter is poorly flexible in the vicinity of the rear end portion of the balloon and the balloon catheter cannot be smoothly inserted into the bent blood vessel.

The present invention has been made based on the above situation.
The object of the present invention is to suppress the relative displacement between the outer tube and the inner tube to some extent when the tube is inserted into the blood vessel, and the balloon is not easily bent even when high pressure is applied to the inside of the balloon. Another object of the present invention is to provide a double-tube structure balloon catheter that maintains the linearity of the balloon shape, has good flexibility near the rear end of the balloon, and can be smoothly inserted into a bent blood vessel. .

The balloon catheter of the present invention is inserted through the outer tube, the balloon attached to the tip of the outer tube, the lumen of the outer tube and the inside of the balloon, and the tip is fixed to the tip of the balloon In a double-tube structure balloon catheter having an inner tube,
The inner tube is fixed to the inner wall of the outer tube at a position spaced from the rear end of the balloon to the base end side,
When the diameter of the balloon is D [mm], the length of the balloon is L [mm], and the distance from the rear end of the balloon to the fixing position of the inner tube is G [mm], the following formula [1A ] Or [1B] and the following expression [2] are satisfied.

Formula [1A]: G ≧ 45 (L / D) -292 (where (L / D) ≦ 8.0)
Formula [1B]: G ≧ 70 (L / D) −495 (where (L / D) ≧ 8.0)
Formula [2]: 30 ≦ G ≦ 150

According to the balloon catheter of the present invention, by providing the above formula [1A] or formula [1B], even when a high pressure such as the rated breaking pressure (RBP) is applied to the inside of the balloon, the balloon is hardly bent and expanded. The linearity of the balloon shape at the time can be maintained.
Further, since the separation distance (G) is 30 mm or more, the flexibility in the vicinity of the rear end of the balloon is ensured, the blood vessel followability is excellent, and even a bent blood vessel can be smoothly inserted. .
Furthermore, since the separation distance (G) is 150 mm or less, the relative displacement between the outer tube and the inner tube can be suppressed to some extent when the tube is inserted into the blood vessel. Can be accurately transmitted to the distal end portion of the catheter, and the occurrence of bellows-like wrinkles on the folded balloon can be prevented.

It is a longitudinal cross-sectional view of the balloon catheter which concerns on one Embodiment of this invention. FIG. 2 is a transverse sectional view (II-II sectional view of FIG. 1) of a balloon catheter according to an embodiment of the present invention. It is a graph which shows the result of the evaluation test 1 (The linearity of the balloon shape at the time of high pressure provision). It is a top view which shows the simulation blood vessel apparatus used by the evaluation test 2 (blood vessel followability). In the evaluation test 2, it is a chart figure which shows the load change at hand measured about an example of the balloon catheter for a control | contrast by which the inner tube is not melt | fused by the inner wall of an outer tube. In the evaluation test 2, it is a chart figure which shows the load change of the hand measured about the balloon catheter which concerns on the comparative example 9. FIG. In the evaluation test 2, it is a chart figure which shows the load change of the hand measured about the balloon catheter which concerns on the comparative example 10. FIG. In the evaluation test 2, it is a chart figure which shows the load change of the hand measured about the balloon catheter which concerns on Example 14. FIG. In the evaluation test 2, it is a chart figure which shows the load change of the hand measured about the balloon catheter which concerns on Example 16. FIG.

The balloon catheter 1 of this embodiment shown in FIGS. 1 and 2 is used for percutaneous coronary angioplasty (PTCA) or the like.
The balloon catheter 1 is inserted into the outer tube 10, the balloon 20 attached to the distal end of the outer tube 10, the lumen of the outer tube 10 and the inside of the balloon 20, and the distal end portion of the balloon catheter 1 with respect to the distal end portion of the balloon 20. This is a double-tube balloon catheter having an inner tube 30 to which 31 is fixed.
In FIG. 1, 40 is a hypotube connected to the base end side of the

outer tube

10, 50 is a hub attached to the base end side of the

hypotube

40, 55 is a strain relief, and 60 is a core wire.

The outer tube 10 constituting the balloon catheter 1 forms a lumen through which a fluid for expanding the balloon 20 flows.
The outer diameter of the outer tube 10 is usually 0.7 to 1.0 mm, and 0.85 mm is shown as a suitable example.
Further, the inner diameter of the outer tube 10 is usually 0.65 to 0.95 mm, and 0.71 mm as a suitable example.
The length of the outer tube 10 is normally 150 to 450 mm, and is 390 mm as a preferred example.
Examples of the constituent material of the outer tube 10 include synthetic resins such as polyolefin, polyamide, polyether polyamide, polyurethane, nylon, PEBAX (registered trademark) (polyether block amide), and among these, PEBAX is preferable.

A balloon 20 is attached to the tip of the outer tube 10.
The diameter (D) of the balloon 20 at the time of expansion is usually 1.0 to 5.0 mm, preferably 2.0 to 3.5 mm.
The length (L) of the balloon 20 is usually 5 to 40 mm, preferably 15 to 30 mm.
As the constituent material of the balloon 20, the same balloon as that of a conventionally known balloon catheter can be used, and PEBAX can be cited as a suitable material. The strength of the constituent material of the balloon 20 is preferably a flexural modulus of 340 Mpa to 440 Mpa. If the strength is too low, it tends to over-expand and tends to cause wrinkles.

The inner tube 30 constituting the balloon catheter 1 extends to the lumen of the outer tube 10 and the inside (lumen) of the balloon 20, and forms a lumen for inserting a guide wire.
The distal end portion 31 of the inner tube 30 is fixed to the distal end portion of the balloon 20, and an opening 30 </ b> A is formed at the distal end of the inner tube 30.
The proximal end portion of the inner tube 30 is opened on the side surface of the outer tube 10, and the opening 30B serves as a guide wire port.

The outer diameter of the inner tube 30 is normally 0.48 to 0.60 mm, and is 0.53 mm as a preferred example.
Further, the inner diameter of the inner tube 30 is usually 0.35 to 0.45 mm, and is 0.42 mm as a suitable example.
The separation distance from the rear end of the balloon 20 to the opening 30B of the inner tube 30 [distance (S) in the axial direction of the outer tube 10] is usually 150 to 300 mm, and is 230 mm if a suitable example is shown.
As a constituent material of the inner tube 30, the same synthetic resin as that of the outer tube 10 can be exemplified, and among them, PEBAX is preferable.

The metal hypotube 40 constituting the balloon catheter 1 has a distal end portion inserted into the proximal end portion of the outer tube 10 and a proximal end portion inserted into the hub 50.
The hypotube 40 may be made of stainless steel, Ni—Ti, Cu—Mn—Al alloy, or the like, and a spiral slit may be formed at the tip portion thereof.
The length of the hypotube 40 is usually 900 to 1500 mm, and is 1150 mm as a preferred example.

An opening 50B (balloon expansion port) for introducing a fluid for expanding the balloon 20 is formed at the proximal end portion of the hub 50 attached to the hypotube 40.
The hub 50 is provided with an inflator, and the inflator adjusts the pressure for expanding the balloon.

As shown in FIGS. 1 and 2, the inner tube 30 is fixed (fused) to the inner wall of the outer tube 10 at a position FP spaced from the rear end of the balloon 20 toward the proximal end of the catheter by a certain distance. . In FIG. 2, 13 is a fusion resin formed by melting and solidifying constituent materials of the outer tube 10 and the inner tube 30. In the present invention, the inner tube may be fixed (adhered) to the inner wall of the outer tube with an adhesive.

Since the inner tube 30 is fixed to the inner wall of the outer tube 10, the relative displacement between the outer tube 10 and the inner tube 30 accompanying expansion and contraction in the longitudinal direction of the balloon 20 can be suppressed to some extent.
In addition, since the fixing position FP of the inner tube 30 is spaced from the rear end of the balloon 20 by a certain distance, the relative displacement between the outer tube 10 and the inner tube 30 is completely suppressed. However, as will be described later, by adjusting the distance from the rear end of the balloon 20 to the fixing position FP of the inner tube 30 (the axial separation distance (G) of the outer tube 10 shown in FIG. 1), A deviation (elongation in the longitudinal direction of the balloon 20) that can maintain the linearity of the balloon shape at the time of application can be ensured.

The separation distance (G) from the rear end of the balloon 20 to the fixing position FP of the inner tube 30 varies depending on the diameter (D) and length (L) of the balloon 20, but is usually 30 to 150 mm. The thickness is preferably 30 to 70 mm.

When the separation distance (G) is less than 30 mm, the flexibility in the vicinity of the rear end of the balloon is impaired, and such a balloon catheter is inferior in blood vessel followability (Comparative Examples 1 to 3, 8 to later described). 10, 15-17, 22-24, 30-32, 39-41, 50-52, 61-63, 76-78, 93-95).
In addition, when the separation distance (G) is less than 30 mm, it is difficult to satisfy the above formula [1A] and formula [1B].

On the other hand, when the separation distance (G) exceeds 150 mm, the relative displacement between the outer tube and the inner tube cannot be suppressed, and the catheter proximal end is inserted when inserting such a balloon catheter into the blood vessel. It is impossible to accurately transmit the operation at the distal end to the catheter tip, or a bellows-like fold is generated on the folded balloon (Comparative Examples 4 to 7, 11 to 14, 18 to 21 described later) 26-29, 35-38, 46-49, 57-60, 72-75, 89-92, 109-112).

The balloon catheter of the present invention satisfies the above formula [1A] when the ratio (L / D) of the length (L) to the balloon diameter (D) is 8.0 or less. That is, in the balloon catheter of the present invention in which the ratio (L / D) is 8.0 or less, the separation distance (G) is set to [45 (L / D) -292] or more.
The separation distance (G) when the ratio (L / D) is 8.0 or less is preferably [45 (L / D) -290] or more.
Depending on the balloon catheter that does not satisfy the formula [1A], it is not possible to sufficiently ensure the elongation in the longitudinal direction of the balloon, and the linearity of the balloon shape cannot be maintained when a high pressure is applied (Comparative Example 1, which will be described later). 8, 15, 16, 22-25, 30-34, 39-45, 50-56).

The balloon catheter of the present invention satisfies the above formula [1B] when the ratio (L / D) of the length (L) to the balloon diameter (D) is 8.0 or more. That is, in the balloon catheter of the present invention in which the ratio (L / D) is 8.0 or less, the separation distance (G) is set to [70 (L / D) -495] or more.
The separation distance (G) when the ratio (L / D) is 8.0 or more is preferably [70 (L / D) -492] or more.
Depending on the balloon catheter that does not satisfy the formula [1B], it is not possible to ensure sufficient elongation in the longitudinal direction of the balloon, and the linearity of the balloon shape cannot be maintained when a high pressure is applied (Comparative Examples 39 to 39 described later). 45, 50-56, 61-71, 76-88, 93-110).

<Example 1>
According to the specifications shown in Table 1, an outer tube made of PEBAX having an outer diameter = 0.85 mm and an inner diameter = 0.71 mm, and a diameter (D) = 2.25 mm and a length (L) attached to the tip of the outer tube = 15 mm, ratio (L / D) = 6.7, a balloon made of “PEBAX7033” (flexural modulus = 390 Mpa), an outer diameter of which the tip is fixed to the tip of the balloon = 0.53 mm, 1 and 2 in which the inner tube is fused to the inner wall of the outer tube at a position 30 mm away from the rear end of the balloon to the base end side. A balloon catheter configured as shown in FIG.

<Examples 2 to 13 and Comparative Examples 1 to 7>
19 kinds of balloon catheters having different separation distances (G) in the same manner as in Example 1 except that the separation distance (G) from the rear end of the balloon to the fixing position of the inner tube was changed according to the specifications shown in Table 1. Manufactured.

<Examples 14 to 26, Comparative Examples 8 to 14>
According to the specifications shown in Table 1, except that a balloon having a diameter (D) = 3.00 mm, a length (L) = 20 mm, and a ratio (L / D) = 6.7 was attached to the tip of the outer tube. In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Examples 27 to 39, Comparative Examples 15 to 21>
According to the specifications shown in Table 2, except that a balloon having a diameter (D) = 3.50 mm, a length (L) = 24 mm, and a ratio (L / D) = 6.9 was attached to the tip of the outer tube. In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Examples 40 to 51, Comparative Examples 22 to 29>
According to the specifications shown in Table 2, except that a balloon having a diameter (D) = 2.75 mm, a length (L) = 20 mm, and a ratio (L / D) = 7.3 was attached to the tip of the outer tube In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Examples 52 to 62, Comparative Examples 30 to 38>
According to the specifications shown in Table 3, except that a balloon having a diameter (D) = 2.00 mm, a length (L) = 15 mm, and a ratio (L / D) = 7.5 was attached to the tip of the outer tube In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Examples 63 to 71, Comparative Examples 39 to 49>
According to the specifications shown in Table 3, except that a balloon with a diameter (D) = 2.50 mm, a length (L) = 20 mm, and a ratio (L / D) = 8.0 was attached to the tip of the outer tube In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Examples 72 to 80, Comparative Examples 50 to 60>
According to the specifications shown in Table 4, except that a balloon having a diameter (D) = 3.00 mm, a length (L) = 24 mm, and a ratio (L / D) = 8.0 was attached to the tip of the outer tube In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Examples 81 to 85, Comparative Examples 61 to 75>
According to the specifications shown in Table 4, except that a balloon having a diameter (D) = 3.50 mm, a length (L) = 30 mm, and a ratio (L / D) = 8.6 was attached to the tip of the outer tube. In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Examples 86 to 88, Comparative Examples 76 to 92>
According to the specifications shown in Table 5, except that a balloon having a diameter (D) = 2.25 mm, a length (L) = 20 mm, and a ratio (L / D) = 8.9 was attached to the tip of the outer tube. In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

<Comparative Examples 93 to 112>
According to the specifications shown in Table 5, except that a balloon having a diameter (D) = 2.50 mm, a length (L) = 24 mm, and a ratio (L / D) = 9.6 was attached to the tip of the outer tube. In the same manner as in Examples 1 to 13 and Comparative Examples 1 to 7, 20 types of balloon catheters having different separation distances (G) were manufactured.

For each of the balloon catheters obtained in Examples 1 to 88 and Comparative Examples 1 to 112, the following evaluation tests 1 to 3 were performed to determine the linearity of the balloon shape, the blood vessel followability at the time of high pressure, The prevention effect was evaluated.

<Evaluation Test 1 (Linearity of the balloon shape when high pressure is applied)>
The inflator was attached to the hub constituting the balloon catheter, thereby applying a rated breaking pressure (14 atm) and observing the shape of the balloon.
The evaluation criteria are “x” when the expanded (over-inflated) balloon is curved and the inner tube is in contact with the inner wall of the balloon at an intermediate position in the length direction, and the linearity of the balloon shape without contacting the inner wall. When it was maintained, “○” was given.
The results are also shown in Tables 1 to 5 below.

In addition, the value of the ratio (L / D) of the mounted balloons and the separation distance (example) of the catheters mounted with the balloons of the respective ratios (L / D) that were evaluated as “◯” (Example) FIG. 3 is a graph plotting the minimum value of G) and the maximum value of the separation distance (G) of the evaluation (comparative example) where the evaluation was “×” (in FIG. 3, “◯” indicates an example). Plot points according to the above, “×” is a plot point according to the comparative example.)

<Evaluation Test 2 (Vessel Tracking)>
Operation is performed by inserting and discharging a balloon catheter in a state in which a simulated blood vessel device made of a metal plate in which a simulated blood vessel (PFA resin tube) having the shape shown in FIG. 4 is disposed in a groove is submerged in pure water. The load change at hand was measured.

As an evaluation standard, the average value (F) of the load applied to the hand when the tip of the catheter passes through the curved portion of the simulated blood vessel (210 to 500 mm from the insertion port) is measured, and the inner tube is attached to the inner wall of the outer tube. For the control balloon catheter that is not fused, the average value (F ₀ ) of the load applied to the hand when the tip of the catheter passes through the curved portion of the simulated blood vessel is measured, and (F / F ₀ ) is 1. .05 or higher was rated as “x”, and (F / F ₀ ) was lower than 1.05 as “◯”.
The results are also shown in Tables 1 to 5 below.

Further, a control balloon catheter in which the inner tube is not fused to the inner wall of the outer tube [diameter (D) = 3.00 mm, length (L) = 20 mm, ratio (L / D) = 6.7] FIG. 5 shows a chart showing the load change applied to the measured hand.
Further, Comparative Example 9 (separation distance (G) = 10 mm), Comparative Example 10 (separation distance (G) = 20 mm), Example 14 (separation distance (G) = 30 mm), Example 16 (separation distance (G)) FIG. 6, FIG. 7, FIG. 8, and FIG.

Here, the average value (F ₀ ) of the load in the control balloon catheter is 53.9 gf (FIG. 5), and the average load in the balloon catheter according to Comparative Example 9 (separation distance (G) = 10 mm). The value (F) is 59.5 gf (F / F ₀ = 1.10), and the average value (F) of the load in the balloon catheter according to Comparative Example 10 (separation distance (G) = 20 mm) is 62.gf.
_{0gf (F / F 0 = 1.15} ), Example 14 (distance (G) = 30 mm) average value of the load in a balloon catheter according to (F) is _{53.6gf (F / F 0 = 0.99} ) The average value (F) of the load on the balloon catheter according to Example 16 (separation distance (G) = 50 mm) was 52.7 gf (F / F ₀ = 0.98).

Further, Comparative Examples 2, 16, 23, 31, 40, 51, 62, 77, and 94 (separation distance (G) = 10 mm) showed almost the same load change as FIG. 6 (Comparative Example 9).
Further, Comparative Examples 3, 17, 24, 32, 41, 52, 63, 78, and 95 (separation distance (G) = 20 mm) showed almost the same load change as FIG. 7 (Comparative Example 10).
Further, other examples show almost the same load change as in FIG. 8 (Example 14) and FIG. 9 (Example 16), and (F / F ₀ ) is less than 1.05 in any example. Met.

<Evaluation Test 3 (Effect of preventing wrinkles in a balloon)>
After holding the distal end of the balloon catheter (inner tube) in contact with the wall and holding the outer tube (base end side from the formation position of the opening on the proximal end side of the inner tube) and applying force in the distal direction Then, it was confirmed whether or not the balloon was contracted to have a bellows shape.

As the evaluation criteria, the case where the shrinkage rate in the length direction was 5% or more was “x”, and the case where the shrinkage rate was less than 5% was “◯”.
The results are also shown in Tables 1 to 5 below.

From the results shown in Tables 1 to 5 and FIG. 3, the minimum value of the separation distance (G) that can maintain the linearity of the balloon shape when a high pressure (rated breaking pressure) is applied depends on the ratio (L / D). Was confirmed.
When the ratio (L / D) is 8.0 or less, the separation distance (G) is [45 (L / D) -292] or more, and the ratio (L / D) is 8.0 or more. It was also confirmed that the linearity of the balloon shape can be maintained if the separation distance (G) is [70 (L / D) -495] or more.

Further, from the results shown in Tables 1 to 5 and FIGS. 5 to 9, it was confirmed that when the separation distance (G) is 30 mm or more, good blood vessel followability can be exhibited regardless of the shape and size of the balloon. It was.

Further, from the results shown in Tables 1 to 5, by setting the separation distance (G) to 150 mm or less, the relative displacement between the outer tube and the inner tube can be suppressed to some extent, and the balloon has a bellows shape. It was confirmed that generation of soot can be prevented.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications can be made.
For example, the balloon catheter of the present invention may be a balloon catheter (so-called over-the-wire balloon catheter) having a structure in which the proximal end side of the inner tube extends to the hub and the opening of the proximal end is provided in the hub. .

DESCRIPTION OF SYMBOLS 1 Balloon catheter 10 Outer tube 20 Balloon 30 Inner tube 31 Tip part 30A Opening 30B Opening (guide wire port)
40 Hypotube 50 Hub 50B Opening (Balloon expansion port)
55 Strain relief 60 Core wire

Claims

A double tube having an outer tube, a balloon attached to the tip of the outer tube, and a lumen of the outer tube and an inner tube inserted into the balloon and having the tip fixed to the tip of the balloon In a tubular balloon catheter,
The inner tube is fixed to the inner wall of the outer tube at a position spaced from the rear end of the balloon to the base end side,
When the diameter of the balloon is D [mm], the length of the balloon is L [mm], and the distance from the rear end of the balloon to the fixing position of the inner tube is G [mm], the following formula [1A ] Or [1B] and the following formula [2] are satisfied.
Formula [1A]: G ≧ 45 (L / D) -292 (where (L / D) ≦ 8.0)
Formula [1B]: G ≧ 70 (L / D) −495 (where (L / D) ≧ 8.0)
Formula [2]: 30 ≦ G ≦ 150
The following formula [1A '] or formula [1B'] is established, The balloon catheter according to claim 1 characterized by things.
Formula [1A ′]: G ≧ 45 (L / D) -290 (where (L / D) ≦ 8.0)
Formula [1B ′]: G ≧ 70 (L / D) -492 (where (L / D) ≧ 8.0)
3. The balloon catheter according to claim 1, wherein the distance G is 30 to 70 mm.