JPWO2013145453A1 - Balloon catheter - Google Patents

Abstract

[PROBLEMS] To prevent a portion other than a stenosis portion from being pressed by a main body portion of a balloon even when the proximal end of the balloon is expanded during expansion, thereby improving safety and convenience. Provided is a balloon catheter. A balloon catheter (10) includes an inner tube shaft (40), an outer tube shaft (50) defining a lumen (51) through which fluid can flow, and a balloon (20) expanded by injecting fluid into the inner space (21). The balloon is provided at the boundary portion 25b between the main body 20 of the balloon and the proximal cone portion 24, and in a state before the fluid is injected, from the proximal contrast marker on the inner tube shaft. Also has a contrast section 26 located on the tip side. [Selection] Figure 2

Description

  The present invention relates to a balloon catheter used in the medical field.

  As a technique for dilating a stenosis formed in a blood vessel of a living body, a so-called percutaneous arterial expansion (PTA) or percutaneous coronary artery dilatation (PTCA) performed using a balloon catheter is performed. Percutaneous Transluminal Coronary Angiology) is widely known.

  A general balloon catheter includes a balloon into which a fluid as a pressurized medium is injected, and an inner tube through which a guide wire for guiding the balloon catheter to a predetermined treatment site (stenosis) in the living body is inserted. And an outer tube that divides a lumen through which fluid can flow between the inner tube and the balloon. The balloon has a distal end side fixed to the inner tube and a proximal end side fixed to the outer tube. In addition, the balloon catheter is provided with an X-ray contrast marker on the inner tube or the outer tube in order to enable smooth guidance of the balloon to the treatment site, or a main body portion that presses the stenosis portion in the balloon. A contrast section for enabling easy confirmation of the position and the expanded state of the main body is provided on the balloon (see Patent Document 1 below).

JP 2000-070375 A

  As described in Patent Document 1, attempts have been made to improve the convenience of the balloon catheter by providing each part of the balloon catheter with X-ray contrast, but on the other hand, the stenosis is expanded. During the procedure, the main body of the balloon is displaced from the stenosis, and the expansion work cannot be performed in a state where the balloon is aligned at an appropriate position, and a part other than the stenosis is pressed. . The cause of this problem is that when the balloon is expanded by a high-pressure pressurized medium, the proximal end of the balloon having flexibility expands to the proximal end side together with the outer tube, and the main body portion of the balloon moves along with the expansion of the balloon. There is a difference from the initial position. That is, originally, it is possible to prevent a portion other than the stenosis from being pressed by confirming the boundary of the main body with the X-ray contrast unit. If the expansion occurs, it becomes impossible to accurately grasp the boundary of the main body.

  Therefore, the present invention can prevent a portion other than the constricted portion from being pressed by the main body portion of the balloon even when the proximal end of the balloon expands during expansion, and thus is safe and convenient. It is an object of the present invention to provide a balloon catheter that is improved.

  To achieve the above object, the balloon catheter according to the present invention includes an inner tube shaft through which a guide wire is inserted, an outer tube shaft that defines a lumen through which fluid can flow, and a distal end side joined to the inner tube shaft, And a base end side is joined to the outer tube shaft, and a balloon is defined by injecting the fluid into the inner space, partitioning an inner space communicating with the lumen with the inner tube shaft, A distal-side contrast marker and a proximal-side contrast marker provided on the inner tube shaft; and a contrast portion provided on the balloon. In addition, the balloon has a main body portion, a distal-end-side conical portion positioned at the distal end relative to the main body portion of the balloon, and a proximal-end-side conical portion positioned closer to the proximal end than the main body portion of the balloon. . The contrast portion of the balloon is provided at a boundary portion between the main body portion and the base end side conical portion, and in a state before the fluid is injected, the base end side of the inner tube shaft It is located in the front end side rather than the contrast marker.

  In the present invention, a contrast portion is provided at the boundary between the main body portion of the balloon included in the balloon catheter and the proximal end side cone portion of the balloon, and this contrast portion is in a state before the expansion fluid is injected into the balloon. In FIG. 5, the proximal end side contrast marker of the inner tube shaft is positioned on the distal end side. For this reason, when the operator expands the balloon, the proximal end of the balloon expands with the expansion of the balloon, and when the contrast portion provided on the balloon moves to the proximal end side with the expansion, Since the boundary part of the main body part of the balloon can be clearly grasped by the relative positional relationship between the contrast part and the proximal side contrast marker of the inner tube shaft, a part other than the stenosis part is pressed by the main body part of the balloon. Can be reliably prevented. Therefore, according to the present invention, it is possible to provide a balloon catheter that is improved in safety and convenience as compared with a conventional balloon catheter.

  Also, when the balloon contrast part is provided at a position that overlaps the proximal contrast marker on the inner tube shaft when the pressure in the balloon reaches the rated burst pressure (pressurization limit) ± 10% range When the balloon is expanded by a pressure in the vicinity of the rated burst pressure, the boundary part of the main body of the balloon does not move to the proximal side of the contrast marker on the proximal side of the inner tube shaft. It is possible to press the stenosis part with an appropriate pressure while preventing a portion other than the stenosis part from being pressed by the main body part. Furthermore, when the balloon is expanded by a pressure in the vicinity of the rated burst pressure, by confirming the position of the contrast portion of the balloon, the position of the boundary portion of the main body of the balloon is confirmed, and the pressure in the balloon reaches a predetermined pressure. Since it can be confirmed that the pressure has increased, it is possible to prevent the balloon from being damaged such as rupture due to excessive pressure in the balloon during the procedure.

  In addition, when the contrast portion of the balloon is formed with lower X-ray contrast than the contrast marker on the proximal end of the inner tube shaft, the contrast portion of the balloon and the proximal end of the inner tube shaft under fluoroscopy The contrast with the side contrast marker makes it possible to clearly determine that the contrast portion overlaps the proximal contrast marker on the inner tube shaft. It becomes possible to confirm the position of the portion more reliably.

It is a top view which shows the balloon catheter which concerns on embodiment of this invention. 2A is a cross-sectional view showing a cross section taken along line 2A-2A in FIG. 1, and FIG. 2B is a cross-sectional view showing a cross section taken along line 2B-2B in FIG. It is sectional drawing which shows the state before expanding the balloon with which a balloon catheter is equipped, and the state after expanding. It is a fragmentary sectional view which shows the balloon catheter which concerns on the modification of embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio.

  FIGS. 1 and 2 are diagrams showing the configuration of each part of the balloon catheter 10 according to the embodiment, and FIG. 3 is a diagram for explaining the operation of the balloon catheter 10 according to the embodiment. In the following description, the left side in each figure is referred to as “front end side”, and the right side is referred to as “base end side”.

  As shown in FIG. 1, in general, the balloon catheter 10 includes a long shaft body 30, a balloon 20 provided on the distal end side of the shaft body 30, and a hand provided on the proximal end side of the shaft body 30. And a hub 60 as an operation unit.

  In the balloon catheter 10 according to the present embodiment, the shaft body 30 is inserted into a living organ, for example, a coronary artery, and the balloon 20 provided on the distal end side is expanded at the stenosis (lesion), thereby expanding the stenosis. This is a so-called PTCA dilatation catheter. However, the present invention can be applied to catheters other than such PTCA dilatation catheters. For example, stenosis formed in living organs such as other blood vessels, bile ducts, trachea, esophagus, urethra, and other organs. Applicable to catheters for the purpose of treatment and improvement of the head.

  In the present embodiment, a so-called over-the-wire type balloon catheter that allows a guide wire to be inserted into the balloon catheter 10 through the opening 61 of the hub 60 provided on the proximal end side of the shaft body 30. As will be described later, the present invention is applied to another type, for example, a so-called rapid exchange type balloon catheter in which a guide wire is inserted obliquely from a substantially middle portion of a shaft body. Is also possible.

  As shown in FIGS. 2A and 2B, the shaft body 30 includes a flexible inner tube shaft 40, a coaxial arrangement with the inner tube shaft 40, and a distal end of the inner tube shaft 40. And a flexible outer tube shaft 50 provided at a position retracted by a predetermined length. The proximal end of the inner tube shaft 40 and the proximal end of the outer tube shaft 50 are respectively fixed to predetermined portions of the hub 60.

  The inner tube shaft 40 is provided with a guide wire insertion lumen 41 through which a guide wire can be inserted. The guide wire insertion lumen 41 communicates with an opening 61 provided at the proximal end of the hub 60. A fluid as a pressurized medium for expanding the balloon 20 can flow between the outer surface of the inner tube shaft 40 and the inner surface of the outer tube shaft 50 and between the outer surface of the inner tube shaft 40 and the hub 60. Lumen 51 is partitioned. The lumen 51 communicates with a port 62 provided in the hub 60 and an internal space 21 provided in the balloon 20.

  A fluid tube (not shown) connected to a fluid supply source (not shown) for supplying a fluid can be connected to the port 62 provided in the hub 60 in a liquid-tight and air-tight manner.

  The constituent material of the inner tube shaft 40 may be any synthetic resin having flexibility, such as polyethylene, polypropylene, ethylene-propylene copolymer, polyolefin such as ethylene-vinyl acetate copolymer, and soft polychlorinated resin. Examples thereof include thermoplastic resins such as vinyl, various rubbers such as silicone rubber and latex rubber, various elastomers such as polyurethane elastomer, polyamide elastomer, and polyester elastomer, and crystalline plastics such as polyamide, crystalline polyethylene, and crystalline polypropylene. In addition, for example, an antithrombotic substance such as heparin, prostaglandin, urokinase, or arginine derivative may be blended in these materials to obtain an antithrombotic material.

  As a constituent material of the outer tube shaft 50, the same material as that of the inner tube shaft 40 can be used. Further, a portion having contact with blood in the outer tube shaft 50 (for example, the outer surface of the outer tube shaft) may be coated with a substance having antithrombotic properties. In this way, excellent antithrombogenicity can be imparted to the balloon catheter 10, and even during a long-time procedure such as IABP, a thrombus is unlikely to occur in the outer tube shaft 50, and the procedure can be performed safely.

  Examples of the constituent material of the hub 60 include thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate styrene copolymer.

  The balloon 20 expands (expands) and contracts as its internal volume increases or decreases due to a change in pressure (internal pressure) in the balloon 20. As shown in FIG. 2B, the balloon 20 includes a main body portion 22 that can be expanded in a cylindrical shape, a distal-end-side conical portion 23 located at the distal end of the main body portion 22, and a proximal end relative to the main body portion 22. And a proximal-side conical portion 24 located therein. A boundary portion 25 a is formed between the main body portion 22 and the distal end side conical portion 23, and a boundary portion 25 b is also formed between the main body portion 22 and the proximal end side conical portion 24.

  The main body 22 has a substantially linear shape before and after expansion (see FIG. 3). The distal end side conical portion 23 is a portion provided so that the outer diameter gradually decreases from the main body portion 22 toward the distal end side. The base end side conical portion 24 is a portion provided so that the outer diameter gradually decreases from the main body portion 22 toward the base end side. The expansion of the stenosis is performed by expanding the main body 22 positioned in the stenosis and expanding the stenosis by this expansion.

  The distal end side of the balloon 20 is joined to the inner tube shaft 40, and the proximal end side is joined to the outer tube shaft 50. For the joining, a known method such as adhesion or fusion can be adopted. In the illustrated embodiment, the tip of the balloon 20 is directly attached to the inner tube shaft 40. For example, the tip of the balloon 20 is attached to a tip 70 which will be described later, and the inner tube is inserted via the tip 70. It may be attached to the shaft 40.

  An internal space 21 into which a fluid flows is defined between the balloon 20 and the inner tube shaft 40. The internal space 21 communicates with the lumen 51. The fluid that drives the expansion and contraction of the balloon 20 is injected into the internal space 21 through the lumen 51 and discharged from the internal space 21 through the lumen 51. The operation of introducing the balloon catheter 10 into the living body can be performed in a state where the balloon 20 is deflated and the balloon 20 is wound around the outer surface of the inner tube shaft 40. Known methods and forms used for balloon catheters in the medical field can be adopted as the winding method and its form.

  The material of the balloon 20 is preferably a material having a certain degree of flexibility and a hardness that can send blood, for example, polyethylene such as polyethylene, polypropylene, ethylene-propylene copolymer, polyester such as polyethylene terephthalate, polychlorinated Examples thereof include vinyl, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate copolymer, thermoplastic resins such as polyurethane, polyamide, polyamide elastomer, silicone rubber, latex rubber and the like. The balloon 20 may be formed in a single layer structure using these materials, or may be formed in a laminate structure of two or more layers. Further, the balloon 20 may be coated with a substance having antithrombotic properties as with the outer tube shaft 50.

The fluid used for expanding the balloon 20 may be gas or liquid, and examples thereof include gas such as helium gas, CO ₂ gas, and O ₂ gas, and liquid such as physiological saline and contrast medium.

  A distal end tip 70 having a curved distal end surface is fixed to the distal end of the inner tube shaft 40. By providing the distal tip 70, it is possible to prevent an in vivo organ from being damaged when the balloon catheter 10 is introduced.

  As a constituent material of the tip 70, a material having a certain degree of flexibility is preferable. For example, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, soft polyvinyl chloride, polyamide And thermoplastic resins such as polyamide elastomer and polyurethane, silicone rubber, latex comb and the like, and the above thermoplastic resins are preferable. In order to make it possible to confirm the introduction position of the balloon catheter 10, the distal tip 70 may be provided with an X-ray contrast property (X-ray impermeability). Examples of a method for providing X-ray contrast properties include embedding a metal member formed of Pt, Pt alloy, W, W alloy, Ag, Ag alloy, or the like in the tip 70, or mixing metal powder. .

  As shown in FIG. 2B, the inner tube shaft 40 is provided with a distal contrast marker 42 and a proximal contrast marker 43. The distal contrast marker 42 and the proximal contrast marker 43 are radiopaque markers formed on the outer surface of the inner tube shaft 40 and made of a material having radiopacity. This marker can be composed of, for example, Pt, Pt alloy, W, W alloy, Ag, Ag alloy, or the like. In the illustrated embodiment, the distal-side contrast marker 42 and the proximal-side contrast marker 43 are formed on the outer surface of the inner tube shaft 40 as shown by broken lines. You may form in a part dot shape, may form in an inner surface, or may form with the pattern of a predetermined shape.

  The distal-side contrast marker 42 and the proximal-side contrast marker 43 are provided apart in the axial direction by a predetermined distance L1. The distal contrast marker 42 is arranged so that the position in the axial direction coincides with the boundary portion 25a of the balloon 20. More specifically, the distal side contrast marker 42 is arranged so that the center position in the width direction (left and right direction in the figure) overlaps with the center position of the boundary portion 25a. On the other hand, the proximal contrast marker 43 is disposed at a position away from the boundary portion 25b of the balloon 20 in the axial direction by a predetermined distance L2.

  As shown in FIG. 2B, the balloon 20 is provided with a contrast portion 26 provided at a boundary portion 25b between the main body portion 22 and the proximal end side conical portion 24 of the balloon 20. The contrast section 26 is provided so as to be positioned on the distal side of the proximal end side contrast marker 43 of the inner tube shaft 40 in a state before the fluid is injected into the balloon 20. The contrast unit 26 provided in the balloon 20 embeds, for example, Pt, Pt alloy, W, W alloy, Ag, Ag alloy or the like in the boundary portion 25b, or joins these materials to the outer surface of the balloon 20. Can be configured. In the case where the balloon 20 has a laminate structure composed of a plurality of layers instead of a single layer, it is preferable that the balloons 20 be disposed on the inner surface or the outer surface of the balloon 20 without being disposed between the layers.

  Although the width of the contrast portion 26 of the balloon 20 is not particularly limited, for example, it is preferably formed with a dimension of 5% or less of the axial length of the main body portion 22. For example, when the main body portion 22 is formed with a length of 20 mm, the contrast portion 26 can be formed with a width of 1 mm or less. The width of the contrast portion 26 of the balloon 20 is preferably smaller than the width of the proximal contrast marker 43 of the inner tube shaft 40. As will be described later, when the contrast unit 26 and the proximal contrast marker 43 overlap each other, it is easy to determine the overlapping state. In addition, as shown by the broken line in the figure, the contrast unit 26 is formed on the outer surface of the balloon 20 in a circumferential shape. You may form in a dot shape in a part, or may form with the pattern of a predetermined shape.

  Next, the operation of the balloon catheter 10 according to the embodiment will be described with reference to FIG.

  FIG. 3 shows the balloon 20 before expansion (state 1) and the balloon 20 after expansion (state 2).

  When performing a procedure for expanding the stenosis formed in the living body, the main body 22 of the balloon 20 is aligned with the stenosis. This alignment can be performed, for example, by aligning the distal-side contrast marker 42 provided on the inner tube shaft 40 to the distal end side of the stenosis under fluoroscopy.

  After alignment, when a fluid is injected into the internal space 21 of the balloon 20 at a high pressure and the balloon 20 is expanded, the entire balloon 20 expands in the radial direction (indicated by an arrow a in the figure). Along with this expansion, the main body portion 22 of the balloon 20 presses and widens the narrowed portion. At this time, a phenomenon occurs in which the proximal end of the balloon 20 to which the outer tube shaft 50 is connected extends toward the proximal end in the axial direction (indicated by an arrow b in the figure). This is because when the balloon 20 is expanded by the fluid injected at a high pressure, the expansion in the axial direction occurs simultaneously with the expansion in the outer diameter direction. It should be noted that the tip of the balloon 20 is joined to the inner tube shaft 40 and is hardly affected by pressure change at the time of fluid injection, so that the balloon 20 hardly extends toward the tip.

  When expansion of the balloon 20 toward the proximal end occurs, the contrast unit 26 provided on the balloon 20 also moves toward the proximal end along with the expansion. When the pressure in the balloon 20 reaches a predetermined pressure, the contrast portion 26 of the balloon 20 and the proximal contrast marker 43 of the inner tube shaft 40 overlap. An operator who performs a procedure using the balloon catheter 10 clearly identifies the position of the boundary 25b on the proximal end side of the main body 22 of the balloon 20 by checking the contrast unit 26 provided on the balloon 20 during the procedure. Can grasp.

  In the conventional balloon catheter, in order to confirm the position of the boundary part of the balloon based only on the position of the contrast marker on the proximal side of the inner tube provided in advance in a location that coincides with the boundary part of the main body part of the balloon, When the balloon is elongated, the boundary portion of the balloon main body cannot be clearly grasped. Therefore, the balloon may be expanded in a state where the main body of the balloon is located at a site other than the stenosis. On the other hand, according to the balloon catheter 10 according to the present embodiment, the boundary between the main body portion 22 of the balloon 20 due to the relative positional relationship between the contrast portion 26 of the balloon 20 and the proximal contrast marker 43 of the inner tube shaft 40. Since the portion 25b can be clearly grasped, even when the balloon 20 extends to the proximal end side, it is possible to reliably prevent a portion other than the stenosis portion from being pressed by the main body portion 22 of the balloon 20. be able to.

  Here, in the balloon catheter 10 according to the present embodiment, the contrast unit 26 of the balloon 20 has an inner tube when the pressure in the balloon 20 reaches a range of rated burst pressure (pressurization limit) ± 10%. It is preferable to be provided at a position overlapping the proximal end side contrast marker 43 of the shaft 40. With this configuration, the boundary portion 25b of the body portion 22 of the balloon 20 is more than the proximal contrast marker 43 of the inner tube shaft 40 when performing an operation of expanding the balloon 20 with a pressure near the rated burst pressure. Since it does not move to the base end side, it becomes possible to press the stenosis part with an appropriate pressure while preventing the body part 22 of the balloon 20 from pressing the part other than the stenosis part. Further, when the balloon 20 is expanded by a pressure in the vicinity of the rated burst pressure, the position of the contrast portion 26 of the balloon 20 is confirmed, thereby confirming the position of the boundary portion 25b of the main body portion 22 of the balloon 20 and the inside of the balloon 20 It is possible to confirm that the pressure of the balloon 20 has increased to a predetermined pressure, so that the pressure in the balloon 20 is excessively increased during the procedure, so that the balloon 20 may be damaged such as rupture. It becomes possible to prevent. The state in which the contrast portion 26 of the balloon 20 and the proximal contrast marker 43 of the inner tube shaft 40 overlap may be a state in which at least a part of both overlaps, and the state in which they overlap completely. It does not have to be.

  As an example of a combination for obtaining the above effects, when a balloon 20 having a rated burst pressure of 1216 to 2533 kPa (12 atm to 25 atm) composed of polyamide or polyamide elastomer, or a mixture thereof is used. The distance L2 between the boundary portion 25b of the main body portion 22 of the balloon 20 and the proximal contrast marker 43 of the inner tube shaft 40 in a state before the fluid is injected is set to 1 to 10 mm.

  Further, in the balloon catheter 10 according to the present embodiment, the contrast portion 26 of the balloon 20 is preferably formed with lower X-ray contrast than the proximal contrast marker 43 of the inner tube shaft 40. With this configuration, the contrast unit 26 is based on the contrast between the contrast unit 26 of the balloon 20 and the proximal contrast marker 43 of the inner tube shaft 40 under X-ray fluoroscopy. 43 can be clearly determined to be in a state of being overlapped with 43, so that when the balloon 20 is expanded, the position of the boundary portion 25b of the main body portion 22 of the balloon 20 is more reliably confirmed. It becomes possible. The adjustment of the X-ray contrast property of the contrast unit 26 of the balloon 20 and the adjustment of the X-ray contrast property of the proximal contrast marker 43 may be adjusted by appropriately combining the materials exemplified above. The amount of each material may be adjusted, and the method is not particularly limited.

<Modification>
In FIG. 4, the balloon catheter 100 which concerns on the modification of embodiment mentioned above is shown.

  In the embodiment described above, the present invention has been described through an over-the-wire type balloon catheter. However, the present invention can also be applied to, for example, a rapid exchange type balloon catheter as illustrated. In the following description, the same members as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The configuration of the balloon catheter 100 will be briefly described. The distal end of the balloon 20 is fixed to the inner tube shaft 40 via a distal tip 70 attached to the distal end of the balloon catheter 100. The proximal end of the balloon 20 is fixed to the outer tube shaft 50. The inner tube shaft 40 includes a guide wire lumen (not shown) through which a guide wire can be inserted, and a proximal end is led out from a predetermined portion of the outer tube shaft 50 to the outside of the shaft body 30. A lumen 51 through which a fluid for expanding the balloon 20 is circulated is formed between the outer tube shaft 50 and the inner tube shaft 40.

  The inner tube shaft 40 is provided with a distal contrast marker 42 and a proximal contrast marker 43, and the balloon 20 is formed at a boundary portion 25 b between the main body portion 22 and the proximal cone portion 24 of the balloon 20. An enhanced contrast unit 26 is provided. The contrast section 26 of the balloon 20 is positioned on the distal side of the proximal-side contrast marker 43 of the inner tube shaft 40 in a state before the fluid is injected as shown. For this reason, even when the balloon 20 is extended to the proximal end side during the procedure using the balloon catheter 100, the contrast portion 26 of the balloon 20 and the proximal side contrast marker 43 of the inner tube shaft 40 are used. It is possible to clearly grasp the boundary portion 25b of the main body portion 22 of the balloon 20 by the relative positional relationship. Therefore, it is possible to reliably prevent the body portion 22 of the balloon 20 from pressing a portion other than the narrowed portion.

  It should be noted that the position where the contrast section 26 is provided based on the rated burst pressure of the balloon 20 and the X-ray contrast property of the contrast section 26 of the balloon 20 can be determined based on the proximal contrast marker 43 of the inner tube shaft 40. The point which can be formed lower than that is the same as in the above-described embodiment.

  As mentioned above, although the balloon catheter which concerns on this invention was demonstrated through embodiment and the modification, this invention can be variously modified based on description of a claim, and is not limited only to described embodiment. . That is, according to the present invention, a contrast portion showing a boundary portion between the main body portion and the proximal end side cone portion of the balloon is provided in the balloon, and in a state before the fluid is injected into the balloon, the contrast is increased. Is positioned on the distal end side of the proximal contrast marker of the inner tube shaft, and the balloon is in a position relative to the contrast portion and the proximal contrast marker of the inner tube shaft before and after the expansion of the balloon. The configuration can be changed as long as the configuration capable of grasping the boundary portion of the main body is provided.

  This application is based on Japanese Patent Application No. 2012-068777 filed on March 26, 2012, the disclosure of which is incorporated by reference in its entirety.

10, 100 balloon catheter,
20 balloon,
21 interior space,
22 body part,
23, the tip cone
24 proximal cone,
25b border part,
26 Contrast part,
30 shaft body,
40 Inner tube shaft,
42 distal contrast marker,
43 proximal contrast marker,
50 outer pipe shaft,
51 Lumen for fluid distribution.

Claims (3)

An inner tube shaft through which the guide wire is inserted;
An outer tube shaft defining a lumen through which fluid can flow;
A distal end side is joined to the inner tube shaft, and a proximal end side is joined to the outer tube shaft, and an internal space communicating with the lumen is defined between the inner tube shaft and the inner space. A balloon that is expanded by the injection of fluid;
A distal contrast marker and a proximal contrast marker provided on the inner tube shaft;
An imaging part provided on the balloon,
The balloon has a main body portion, a distal-end-side conical portion located at the distal end relative to the main-body portion of the balloon, and a proximal-end-side conical portion located closer to the proximal end than the main body portion of the balloon,
The contrast portion of the balloon is provided at a boundary portion between the main body portion and the base end side conical portion, and in the state before the fluid is injected, the base end side contrast marker of the inner tube shaft A balloon catheter, which is located on the distal side of the balloon.   The contrast portion of the balloon is provided at a position where it overlaps with a contrast marker on the proximal end of the inner tube shaft when the pressure in the balloon reaches a range of rated burst pressure ± 10%. Item 4. The balloon catheter according to Item 1.   The balloon catheter according to claim 1 or 2, wherein the contrast portion of the balloon has a lower X-ray contrast property than a contrast marker on the proximal end side of the inner tube shaft.

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