WO2015146259A1

WO2015146259A1 - Balloon catheter and method for manufacturing balloon

Info

Publication number: WO2015146259A1
Application number: PCT/JP2015/051727
Authority: WO
Inventors: 裕太土井; 啓二福田; 左興深澤
Original assignee: テルモ株式会社
Priority date: 2014-03-27
Filing date: 2015-01-22
Publication date: 2015-10-01
Also published as: JP2017093472A

Abstract

Provided is a balloon catheter having excellent safety and convenience, whereby a balloon is prevented from coming out of position in a stenosed part when expanded, and adequate pressure can be applied to the stenosed part via an expanding effective part. A balloon (100) provided to a balloon catheter (10) deforms so that the outside diameter of a maximum-outside-diameter part (121) of a distal-end expansion part (120) and the outside diameter of a maximum-outside-diameter part (131) of a proximal-end expansion part (130) are greater than the outside diameter of each part of an expanding effective part (110) until a prescribed expansion pressure (P1) is reached, and when the prescribed expansion pressure (P1) is reached, the balloon (100) deforms so that the outside diameter each part of the expanding effective part (110) is the same or at least the same as the outside diameter of the maximum-outside-diameter part (121) of the distal-end expansion part (120) and the outside diameter of the maximum-outside-diameter part (131) of the proximal-end expansion part (130).

Description

Balloon catheter and balloon manufacturing method

The present invention relates to a balloon catheter used for dilatation of a stenosis and a method for manufacturing a balloon used for the balloon catheter.

As a technique for dilating a stenosis formed in a blood vessel of a living body, a so-called percutaneous arterial dilation (PTA) or percutaneous coronary artery dilatation (PTCA) is performed using a balloon catheter. Percutaneous Transluminal Coronary Angioplasty) is widely known. In the procedure using a balloon catheter, the balloon is introduced from outside the body into the blood vessel, and after positioning the balloon at the stenosis, which is the treatment target site, the balloon is expanded to expand the stenosis, thereby restoring blood flow. I am trying.

Many of the balloons provided in general balloon catheters have a straight barrel shape in which the outer diameter of the portion (expansion effective portion) that applies pressure to the stenosis is substantially constant. According to the balloon in which the expansion effective portion is formed in a straight body shape, it is possible to apply a uniform pressure over a relatively wide range of the narrowed portion. On the other hand, when the balloon is expanded, the balloon moves in the front-rear direction due to the reaction force from the stenosis part and is displaced from the stenosis part. There is a problem that a pressing force is applied to. In particular, when expanding a calcified lesion that has been calcified by a stenosis, the balloon tends to slip as the elasticity and flexibility decrease due to calcification, and thus the above-mentioned positional deviation tends to occur. End up.

For example, Patent Literature 1 includes an expansion effective part (expansion function part) and a fixing part formed on the distal end side and the base end side of the expansion effective part and having a larger outer diameter than the expansion effective part. A balloon catheter is disclosed. The fixing portion is deformed so that the outer diameter is always larger than that of the effective expansion portion, thereby contacting the inner wall of the blood vessel prior to the effective expansion portion, and holding the entire balloon at a specific position. If such a balloon catheter is used, it is considered that the occurrence of the positional deviation of the balloon as described above can be prevented.

JP 2001-9037 A

However, in the balloon provided in the balloon catheter, the expansion effective portion that pushes the stenosis portion is deformed so that the outer diameter is smaller than each fixed portion regardless of the increase in internal pressure. The applied pressure applied to the part is smaller than the applied pressure applied to the inner wall of the blood vessel from the fixed part side. For this reason, a sufficient pressurizing force cannot be applied from the effective expansion portion to the stenosis portion, and a problem that a satisfactory treatment result cannot be obtained may arise.

The present invention has been made in view of the above problems, and prevents the balloon from being displaced from the stenosis when the balloon is expanded and deformed. Further, a sufficient pressure is applied to the stenosis via the effective expansion portion. It is an object of the present invention to provide a balloon catheter excellent in safety and convenience that can be imparted, and a method of manufacturing a balloon used in the balloon catheter.

A balloon catheter according to the present invention is a balloon catheter including a long shaft having flexibility, and a balloon capable of expansion and contraction that is disposed on a distal end side of the shaft, and the balloon is expanded. An expansion effective portion that pushes the constriction portion with deformation, and is positioned on the distal end side and the base end side of the expansion effective portion, and has a larger outer diameter than each portion of the expansion effective portion in a state before being expanded and deformed. A distal end side extended portion and a proximal end side extended portion formed with a maximum outer diameter portion, and until the expansion effective portion reaches a specified expansion pressure that expands and deforms to a predetermined outer diameter, the expansion effective portion When the outer diameter of the maximum outer diameter portion of the distal end side expanded portion and the outer diameter of the maximum outer diameter portion of the proximal end side expanded portion are larger than the outer diameter of each portion, the predetermined expansion pressure is reached. Each of the extended effective parts Outer diameter is deformed outer diameter and the same diameter or the same larger than the diameter of the maximum outer diameter portion of the outer diameter and the proximal-side extension of the maximum outer diameter of the distal-side extension part of the, and wherein the.

According to the balloon catheter of the present invention, a force for positioning and holding the balloon with respect to a predetermined position from the start of the balloon expansion until the internal pressure of the balloon reaches the specified expansion pressure is expanded on the distal side. Can act on the periphery of the stenosis part via the proximal part and the proximal side expansion part, and when the internal pressure of the balloon reaches the specified expansion pressure, an appropriate pressure is applied from the effective expansion part to the stenosis part Can be expanded. Therefore, the balloon catheter excellent in safety and convenience can be provided.

The distal-side expanded portion and the proximal-side expanded portion have the same characteristics as a non-compliant balloon that has a constant diameter after exceeding the specified expansion pressure. It exhibits the same characteristics as an inflating semi-compliant balloon, and the expansion rate in the radial direction accompanying the increase in the expansion pressure after the distal expansion portion and the proximal expansion portion reach the specified expansion pressure is the radial direction of the expansion effective portion. When the balloon is configured to be relatively smaller than the expansion rate, priority is given to the periphery of the stenosis through the distal side expansion part and the proximal side expansion part until the internal pressure of the balloon reaches the specified expansion pressure. In addition, it is possible to maintain the positioning function by applying pressure to the stenosis part preferentially from the effective expansion part after the internal pressure of the balloon reaches the specified expansion pressure. To be able to , It is possible to extend the stenosis more reliably.

In addition, the difference in the compliant characteristics of the distal end side expansion portion and the proximal end side expansion portion and the expansion effective portion is the adjustment by the material material, when the tubular member constituting the balloon is biaxially stretch blow molded in the mold When adjustment is performed by any one of the group consisting of adjustment of expansion magnification and adjustment by a suppressor that suppresses expansion deformation, it becomes possible to set compliant characteristics of each part of the balloon by a relatively simple method. Therefore, it is possible to facilitate the manufacturing work and reduce the manufacturing cost.

In addition, when having a contrast marker indicating the position of the maximum outer diameter portion of the distal end side expansion portion and the maximum outer diameter portion of the proximal end side expansion portion, it is possible to easily align each portion of the balloon with respect to the stenosis portion. Therefore, it becomes possible to realize an even smoother and quicker procedure.

Also, a suitable manufacturing method for manufacturing a balloon applicable to a balloon catheter that can be expanded by applying an appropriate pressure to the stenosis part, and a function for preventing positional deviation from the stenosis part. Can be provided.

It is a figure which simplifies and shows the whole structure of the balloon catheter which concerns on embodiment of this invention. It is a top view which shows the front-end | tip part of the balloon catheter shown in FIG. FIGS. 3A to 3C are cross-sectional views of the distal end portion of the balloon catheter. It is a figure which shows the relationship between the outer diameter of each part of a balloon, and expansion pressure. 5A and 5B are views for explaining the action of the balloon catheter, and are sectional views schematically showing a state when the balloon is introduced into the blood vessel. FIGS. 6A and 6B are views for explaining the action of the balloon catheter, and are cross-sectional views schematically showing a state when the stenosis portion is expanded by the balloon. FIGS. 7A and 7B are cross-sectional views schematically showing a usage example of the balloon catheter according to the comparative example. FIGS. 8A to 8C are cross-sectional views illustrating a method for adjusting the compliant characteristics of the balloon. 9A and 9B are cross-sectional views illustrating a method for manufacturing a balloon.

Hereinafter, embodiments of the present invention will be described 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.

1 to 3 are diagrams for explaining the configuration of each part of the balloon catheter according to the embodiment, FIG. 4 is a diagram showing the relationship between the outer diameter of each part of the balloon and the expansion pressure, and FIGS. 5 and 6 are the embodiments. FIG. 7 is a diagram for explaining the operation of the balloon catheter, FIG. 7 is a diagram showing a usage example of the balloon catheter according to the proportionality, FIG. 8 is a diagram illustrating a method for adjusting the compliant characteristics of the balloon, and FIG. 9 is an embodiment. It is a figure where it uses for description of the manufacturing method of the balloon which concerns on.

As shown in FIG. 1, the balloon catheter 10 according to the present embodiment has a long shaft 20 inserted into a living organ, for example, a coronary artery, and a balloon 100 disposed on the distal end side of the shaft 20 This is a so-called PTCA dilatation catheter that expands and treats the stenosis by expanding the lesion. 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.

As shown in FIG. 1 and FIG. 2, in general, a balloon catheter 10 includes a long shaft 20 having flexibility, and a balloon 100 that can be expanded and contracted and disposed on a distal end side of the shaft 20. And a hub 50 provided on the proximal end side of the shaft 20. The balloon catheter 10 is a so-called rapid exchange type in which an opening 32 through which the guide wire 60 is led out is provided slightly near the distal end side of the intermediate portion of the shaft 20. In the balloon catheter 10, the side on which the hub 50 is provided is defined as the proximal side, and the side on which the balloon 100 is provided is defined as the distal side.

As shown in FIGS. 2 and 3A, the shaft 20 has an inner tube (inner tube shaft) 30 formed with a guide wire lumen 31 through which the guide wire 60 is inserted, and a balloon 100 for expanding. An outer tube (outer tube shaft) 40 that forms an expansion lumen 41 to which an expansion medium is supplied between the outer tube and an outer peripheral surface of the inner tube 30 is provided.

The shaft 20 has a double tube structure in which the inner tube 30 and the outer tube 40 are arranged concentrically. The inner tube 30 is inserted into the balloon 100 and the outer tube 40 from the tip to the opening 32.

As shown in FIG. 3A, the inner tube 30 includes two openings, an opening 32 formed at the proximal end and an opening 33 formed at the distal end. A guide wire lumen 31 extends in communication with 33.

The inner tube 30 is made of a hollow tube material whose proximal end is curved radially outward. The vicinity of the distal end of the inner tube 30 is liquid-tightly joined to the distal end side of the balloon 100 by a known method such as welding, and the vicinity of the proximal end is liquid-tightly near the connection opening 42 formed in the middle of the outer tube 40. It is joined to. The guide wire 60 is inserted from the distal end side into the proximal end side in the guide wire lumen 31 with the opening portion 32 provided at the proximal end of the inner tube 30 and the opening portion 33 provided at the distal end as an inlet or an outlet, respectively. The

The inner tube 30 does not necessarily have to be bent radially outward in the proximal end side, and may extend in a straight line and be liquid-tightly joined in the vicinity of the connection opening 42.

A distal tip 34 is attached to the distal end of the inner tube 30 to prevent the living organ from being damaged when the distal end of the balloon catheter 10 comes into contact with the living organ. The tip chip 34 can be provided with, for example, X-ray contrast properties.

Examples of the material constituting the inner tube 30 include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, thermoplastic resins such as soft polyvinyl chloride, silicone rubber, latex rubber, etc. And various elastomers such as polyurethane elastomer, polyamide elastomer, and polyester elastomer, and crystalline plastics such as polyamide, crystalline polyethylene, and crystalline polypropylene. In these materials, for example, an antithrombotic substance such as heparin, prostaglandin, urokinase, arginine derivative or the like can be blended to obtain an antithrombotic material.

The outer tube 40 is made of a hollow tube material that extends from the proximal end of the balloon 100 to the hub 50. The portion from the tip of the outer tube 40 to the connection opening 42 has a double tube structure that forms an expansion lumen 41 with the inner tube 30. The proximal end of the balloon 100 is liquid-tightly joined to the distal end of the outer tube 40 by a known method such as welding. A hub 50 is attached to the proximal end of the outer tube 40.

As the constituent material of the outer tube 40, for example, the same material as that of the inner tube 30 can be used. It is also possible to coat a substance having antithrombogenic properties on the portion of the outer tube 40 that comes into contact with blood (for example, the outer surface of the outer tube).

As shown in FIG. 1, the hub 50 is provided with a connecting portion 51 that can be connected in a liquid-tight manner with a supply device (not shown) for supplying an expansion fluid such as an indeflator. The expansion fluid can flow into the outer tube 40 via the connection portion 51 of the hub 50. The expansion fluid that has flowed into the outer tube 40 is supplied to the balloon 100 via the expansion lumen 41. The connecting portion 51 of the hub 50 can be configured by, for example, a known luer taper configured such that a fluid tube or the like can be connected and separated.

Next, the configuration of the balloon 100 will be described with reference to FIGS. 3A shows a state before the balloon 100 is expanded and deformed, and FIGS. 3B and 3C show a state after the balloon 100 is expanded and deformed. FIG. 4 shows the relationship between the change in the outer diameter of each part of the balloon 100 and the expansion pressure (internal pressure) of the balloon 100.

As shown in FIGS. 3 (A) to 3 (C), the balloon 100 includes an expansion effective portion 110 that expands the stenosis N with expansion deformation (see FIGS. 6 (A) and (B)), and an expansion effective portion. The distal end side expansion portion 120 positioned on the distal end side of 110 and the proximal end side expansion portion 130 positioned on the proximal end side of the expansion effective portion 110 are provided.

As shown in FIG. 3A, each of the distal-side expanded portion 120 and the proximal-side expanded portion 130 is in a state before being expanded and deformed (before and after the introduction of the balloon 100 into the living body). In a state before the balloon 100 is expanded), the maximum

outer diameter portions

121 and 131 having outer diameters larger than the respective portions of the expansion effective portion 110 are formed.

The expansion effective part 110 is provided at the approximate center of the balloon 100 in the axial direction (left-right direction in FIG. 3A). The distal side expansion part 120 and the proximal side expansion part 130 are separated from the expansion effective part 110. It is provided at substantially symmetrical positions on the distal end side and the proximal end side in the axial direction as viewed.

The distal end side expansion portion 120 has a maximum outer diameter portion 121 having a maximum outer diameter at a substantially central position. Further, a gently inclined portion 122 extending from the maximum outer diameter portion 121 to the distal end side and the proximal end side is also formed. The cross-sectional shape of the distal-side expanded portion 120 is such that the maximum outer diameter portion 121 protrudes in a direction (vertical direction in FIG. 3A) intersecting the axial direction of the balloon 100 and extends from the maximum outer diameter portion 121 to the distal end side and the proximal end. It has a mountain shape whose outer diameter gradually decreases toward the side.

The proximal end side extended portion 130 is formed in substantially the same shape as the distal end side extended portion 120, and has a maximum outer diameter portion 131 formed at a substantially central position, and a distal end side and a proximal end side from the maximum outer diameter portion 131. And an inclined portion 132 extending to the right. Similarly, the cross-sectional shape is a mountain shape in which the maximum outer diameter portion 131 protrudes in a direction intersecting the axial direction of the balloon 100 and the outer diameter gradually decreases from the maximum outer diameter portion 131 toward the distal end side and the proximal end side. .

The distal end side expansion portion 120 and the proximal end side expansion portion 130 are set to have substantially the same non-compliant characteristics and the outer diameter of the maximum outer diameter portion so as to be deformed in substantially the same shape when the balloon 100 is expanded. .

The expansion effective portion 110 is formed to be connected to the inclined portion 122 on the proximal end side of the distal end side expanded portion 120 and the inclined portion 132 on the distal end side of the proximal end side expanded portion 130, and toward the center position in the axial direction. It has a constricted shape with a gradually decreasing outer diameter.

Although the length dimension in the axial direction of each part of the expansion effective part 110, the distal end side expansion part 120, and the proximal end side expansion part 130 is not particularly limited, it should be used for expansion of a stenosis part formed in a blood vessel of a living body. For example, the length of the extension effective portion 110 is about 5 to 50 mm, more preferably about 10 to 40 mm, and the distal end side extension portion 120 and the proximal end side extension portion 130 are The length dimension is about 1 to 8 mm, and more preferably about 2 to 4 mm.

Next, with reference to FIG. 3 and FIG. 4, the relationship between the outer diameter of each part of the balloon 100 and the expansion pressure will be described. 4 indicates a change in the outer diameter D1 at the axial center position of the effective expansion portion 110, and the solid line indicates the outer diameter D2 of the maximum outer diameter portion 121 of the distal end side expansion portion 120 and the proximal end side expansion portion. The change of the outer diameter D3 of the 130 largest outer diameter parts 131 is shown. The outer diameter of each part of the balloon 100 changes as follows in consideration of each function.

As shown in FIGS. 3A and 4, from the start of expansion (at the time of expansion pressure P ₀ ) until the expansion pressure of the balloon 100 reaches the specified expansion pressure P ₁ , from the outer diameter D 1 of the expansion effective portion 110. Also, the outer diameter D2 of the maximum outer diameter portion 121 of the distal end side expansion portion 120 and the outer diameter D3 of the maximum outer diameter portion 131 of the proximal end expansion portion 130 are increased.

Here, the specified expansion pressure P ₁ is a pressure when the outer diameter of the effective expansion portion 110 of the balloon 100 changes to an outer diameter that applies a pressure capable of pushing and expanding the narrowed portion N to be treated. is there. This provision expansion pressure P ₁ is the symptoms of stricture N, intended use and product specifications of the balloon catheter 10 but can be appropriately changed depending on, for example, the recommended extended pressure (NP which is predetermined for each product ) Can be set. When used to extend the stenosis, such as in the brain blood vessel, for example, defined opening pressure _{P 1} may be set to 0.8 Mpa (8 atm).

The outer diameter of each part of the balloon 100 before expansion can be set as follows, for example. The outer diameter D1 of the effective expansion portion 110 is preferably about 0.5 to 2.5 mm, and the outer diameter D2 of the maximum outer diameter portion 121 of the distal end side expansion portion 120 and the maximum outer diameter portion 131 of the proximal end expansion portion 130. The outer diameter D3 is preferably about 1 to 5 mm. The outer diameter D1 of the extension effective portion when it reaches the prescribed expansion pressure P ₁ is, for example, about 1 ~ 5 mm is preferred.

As shown in FIG. 4, the outer diameter of each part of the balloon 100 gradually increases as the expansion pressure increases from the pre-expansion stage P ₀ to the specified expansion pressure P ₁ , but the expansion pressure changes in this way. During this time, the relationship between the outer diameter D1 of the effective expansion portion 110 <the outer diameter D2 of the maximum outer diameter portion 121 of the distal end side expansion portion 120 and the outer diameter D3 of the maximum outer diameter portion 131 of the proximal end side expansion portion 130 is maintained. The During this transition period, the distal end side extended portion 120 and the proximal end side expanded portion 130 function to position the balloon 100 at a predetermined position so that the balloon 100 is not displaced (FIGS. 5A and 5B). )).

As shown in FIGS. 3B and 4, when the expansion pressure reaches the specified expansion pressure P ₁ , the outer diameter D1 of the expansion effective portion 110 is changed to the outer diameter D2 of the maximum outer diameter portion 121 of the distal end side expansion portion 120 and It changes so that it may become the same diameter as the outer diameter D3 of the largest outer diameter part 131 of the base end side expansion part 130. FIG. As a result, it is possible to apply a pressing force to the constriction N from the dilation effective portion 110 (see FIG. 6A).

As shown in FIGS. 3C and 4, when the expansion pressure is further increased, the outer diameter D <b> 1 of the expansion effective portion 110 increases as the expansion pressure increases, and the outer diameter of the maximum outer diameter portion 121 of the distal end side expansion portion 120. It changes so that it may become larger than D2 and the outer diameter D3 of the largest outer diameter part 131 of the base end side expansion part 130. FIG.

Here, the distal-side expansion portion 120 and the proximal-side expansion portion 130 have a radial expansion rate that increases with the expansion pressure after reaching the specified expansion pressure P _{1 from} the radial expansion rate of the expansion effective portion 110. Is also configured to be relatively small. Therefore, since reaching the prescribed expansion pressure P _1, expanding the effective portion 110 by extending greater than the other portions, a greater pressure is applied against the stricture N (FIG. 6 (B) See).

Examples of the material constituting the balloon 100 include polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyesters such as polyethylene terephthalate, polyvinyl chloride, ethylene-vinyl acetate copolymers, and crosslinked ethylene-vinyl acetate copolymers. Examples include polymers, thermoplastic resins such as polyurethane, polyamides, polyamide elastomers, silicone rubbers, latex rubbers, and the like. The balloon 100 can be formed into a single layer structure using these materials, or can be formed into a laminate structure of two or more layers. Similarly to the outer tube 40, the balloon 100 can be coated with a substance having antithrombotic properties.

As described above, since the expansion pressure reaches a predetermined opening pressure P ₁ is, with the increase of the opening pressure, the radial expansion of the distal extension 120 and the proximal extension 130 of the extension effective portion 110 Although it is adjusted so that it becomes smaller than the expansion coefficient in the radial direction, for example, the adjustment by the material of the material, the tubular material (parison) constituting the balloon 100 in the mold It is possible to select at least one of a group consisting of adjustment of the expansion ratio when performing biaxial stretch blow molding and adjustment by the suppressor 180 that suppresses expansion deformation.

The adjustment by the material is a method of adjusting the compliant characteristics of each part by making the material constituting the expansion effective part 110 different from the material constituting the distal end side extended part 120 and the proximal end side extended part 130. For example, as shown in FIG. 8A, the material constituting the distal end side extended portion 120 and the proximal end side expanded portion 130 is made of a material harder than the material constituting the expansion effective portion 110. In addition, when the tube-shaped material forming the balloon 100 is biaxially stretched and blow-molded in the mold, the expansion ratio is adjusted, for example, when the tube-shaped material is blow-molded using the mold. It is possible to adjust the expansion magnification of the unit 120 and the base end side expansion unit 130 by making it higher than the expansion magnification of the expansion effective unit 110. By these methods, for example, the expansion effective part 110 is configured to have the same characteristics as the semi-compliant balloon, and the distal side expansion part 120 and the proximal side expansion part 130 have the same characteristics as the non-compliant balloon. It becomes possible to comprise.

As shown in FIG. 8B, the adjustment method using the restraining tool 180 is performed by winding an elastically deformable cylindrical member such as a rubber band around the distal end side expansion portion 120 and the proximal end side expansion portion 130, a method to configure so that the tip-side extending portion 120 and the proximal extension 130 after the pressure has reached a predetermined opening pressure P ₁ by restraining force from the rubber band is unlikely to deform.

In addition, as a method of adjusting the compliant characteristics of each part of the balloon 100, for example, as shown in FIG. 8C, there is a method of changing the thickness dimension of each part after configuring each part with the same material, It is possible to adjust the film thickness of the distal end side expansion part 120 and the proximal end side expansion part 130 by making the film thickness larger than that of the expansion effective part 110. It is also possible to select a known method such as a method of incorporating particles or the like that change the compliant characteristics into a part of the material. It is also possible to make adjustments by appropriately combining the illustrated methods.

As shown in FIG. 3A, the balloon catheter 10 includes a contrast marker 123 indicating the position of the maximum outer diameter portion 121 of the distal end side expansion portion 120 and the position of the maximum outer diameter portion 131 of the proximal end side expansion portion 130. A contrast marker 133 is provided. Each

contrast marker

123, 133 can be made of, for example, a metal such as platinum, gold, silver, titanium, tungsten, or an X-ray opaque material such as an alloy thereof. Each

contrast marker

123, 133 is formed in a ring shape that covers the outer periphery of the inner tube 30, but is not limited thereto, and may be configured in a chip shape or a block shape, for example. Further, for example, each portion 121, by containing a radiopaque material (particles or the like) in the maximum outer diameter portion 121 of the distal end side expansion portion 120 and the maximum outer diameter portion 131 of the proximal end side expansion portion 130. A contrast marker indicating 131 may be formed.

In the balloon catheter 10, the contrast marker 113 may be provided similarly near the axial center position of the dilation effective portion 110. The contrast marker 113 can be made of the same material and shape as the

other contrast markers

123 and 133.

Next, the operation of the balloon catheter 10 according to the embodiment will be described with reference to FIGS. 5 and 6.

First, at the time of treatment, as shown in FIG. 5A, a balloon catheter 10 is introduced into a predetermined blood vessel B in which a stenosis N is formed. When introducing the balloon catheter 10, a guide wire 60 known in the medical field can be used. The balloon 100 is guided to the narrowed portion N by inserting the guide wire 60 through the guide wire lumen 31 formed in the inner tube 30. At this time, each part of the balloon 100 is positioned with respect to the narrowed part N. For example, the center position of the dilation effective portion 110 of the balloon 100 is arranged near the center position in the extending direction of the stenosis N (the left-right direction in FIG. 5A), and the distal end side expansion portion 120 and the proximal end of the balloon 100 are arranged. Each of the side expansion portions 130 is disposed on both end sides of the narrowed portion N. Positioning can be performed quickly and accurately by confirming the position of each

contrast marker

113, 123, 133 under X-ray contrast.

As shown in FIG. 5B, when the balloon 100 is expanded, the distal end side expanded portion 120 and the proximal end side expanded portion 130 are expanded and deformed to have a larger outer diameter than the expansion effective portion 110, and the distal end side is expanded. The expansion part 120 and the proximal-side expansion part 130 act on the inner wall of the blood vessel around the stenosis N to hold the balloon 100. Thereby, the position of the balloon 100 in the axial direction is fixed. As a result, the displacement of the balloon 100 is preferably prevented while the expansion deformation is performed with the increase in the expansion pressure.

As shown in FIG. 6 (A), defined extended when the pressure P ₁ is reached, extended the effective portion 110 of the balloon 100 is expanded deformed to the same diameter as the front end side extension section 120 and the proximal extension 130. It is possible to apply pressure to the constriction N by the expansion effective portion 110 in a state in which the positional deviation of the balloon 100 is prevented by the distal end expansion portion 120 and the proximal end expansion portion 130.

As shown in FIG. 6B, when the expansion pressure is further increased, the expansion effective portion 110 of the balloon 100 is further expanded and deformed as the expansion pressure increases, while the distal side expansion portion 120 and the proximal side expansion are increased. The expansion rate of the part 130 is reduced. It is possible to apply a larger pressure from the effective expansion portion 110 to the stenosis N while suppressing an increase in the pressure applied to the inner wall of the blood vessel from the distal side expansion portion 120 and the proximal side expansion portion 130. . Accordingly, it is possible to push the stenosis N while reducing the load on the blood vessel inner wall around the stenosis N.

Here, FIG. 7 shows a usage example of the balloon catheter 200 in proportion. The balloon catheter 200 according to the comparative example includes a balloon 210 formed so that the expansion effective portion 211 maintains a straight body shape before and after expansion deformation.

As shown in FIG. 7A, when the balloon 210 is expanded, a pressurizing force is applied to the constricted portion N via the expansion effective portion 211. At this time, as shown in FIG. 7B, the balloon 210 may be displaced in the axial direction due to the reaction force received from the narrowed portion N. In particular, when a calcification symptom occurs in the stenosis N, displacement of the balloon 210 is likely to occur. When the positional deviation of the balloon 210 occurs, a pressure is applied to an unintended part of the inner wall of the blood vessel, which may damage the inner wall of the blood vessel. In addition, a sufficient pressure cannot be applied to the stenosis N, and a satisfactory therapeutic result may not be obtained. With respect to the balloon catheter 200 according to this embodiment, the balloon catheter 10 according to the present embodiment can apply an appropriate pressure to the stenosis N while preventing the displacement of the balloon 100. Therefore, the occurrence of the above problems can be suitably prevented.

As described above, according to the balloon catheter 10 of the present embodiment, during the period from the start of the expansion of the balloon 100 until the internal pressure of the balloon 100 reaches a predetermined opening pressure P ₁ is the balloon 100 in place the force holding and positioning can act against stricture N around through the distal end side extension section 120 and the proximal extension 130 against the internal pressure of the balloon 100 reaches a prescribed expansion pressure P ₁ At this time, since it is possible to perform expansion by applying an appropriate pressure to the constriction N from the expansion effective portion 110, it is excellent in safety and convenience.

In addition, the distal end side expansion portion 120 and the proximal end side expansion portion 130 are configured such that the expansion rate associated with the increase in expansion pressure after reaching the specified expansion pressure P ₁ is relatively smaller than the expansion rate of the expansion effective portion 110. because it is configured to, until the internal pressure of the balloon 100 reaches a predetermined opening pressure P _1, preferentially pressure against stricture N around through the distal end side extension section 120 and the proximal extension 130 while it is possible to maintain the positioning function by applying, after the inner pressure of the balloon 100 reaches a prescribed expansion pressure P ₁ is preferentially pressure against stricture N from the extended valid 110 Since it becomes possible to give, it becomes possible to expand the constriction N more reliably.

Further, the difference in the compliant characteristics of the distal end side expansion portion 120 and the proximal end side expansion portion 130 and the expansion effective portion 110 is adjusted by the material material, and the tubular member constituting the balloon 100 is biaxially stretch blow molded in the mold. Therefore, the compliant characteristics of each part of the balloon 100 are set by a relatively simple method. Therefore, the manufacturing operation can be facilitated and the manufacturing cost can be reduced.

Further, since the

contrast markers

123 and 133 indicating the positions of the maximum outer diameter portion 121 of the distal end side expansion portion 120 and the maximum outer diameter portion 131 of the proximal end side expansion portion 130 are provided, each portion of the balloon 100 is Positioning can be performed easily, and a smoother and quicker procedure can be realized.

Next, with reference to FIG. 9, a method for manufacturing the balloon 100 provided in the balloon catheter 10 will be described.

First, a tubular material (parison) 190 made of a stretchable polymer is first formed. This is preferably performed by a wire coating method by extrusion. As a polymer, what was mentioned above as a constituent material of balloon 100 can be used, for example.

Then, as shown in FIG. 9A, the tubular material 190 is inserted into the mold 300, and one end of the tubular material 190 is sealed. Sealing can be performed using, for example, heat melting, high frequency sealing, forceps, or the like.

9A includes a first movable mold 310 and a second movable mold 320 that are separable. Each of the

movable molds

310 and 320 is formed with

molding surfaces

311 and 321 having a predetermined shape. When the mold 300 is clamped, the basic outer shape of the balloon 100 (expanded deformation shown in FIG. 3A) is formed between the molding surface 311 of the first movable mold 310 and the molding surface 321 of the second movable mold 320. A cavity 330 having a shape matching the previous shape is formed.

As shown in FIG. 9A, after the tube-shaped material 190 is arranged in the mold 300, the heater 300 (not shown) is operated to heat the mold 300. Heating is performed until the temperature of the portion forming the balloon 100 in the tubular material 190 reaches a temperature in the range from the second order transition temperature to the first order transition temperature of the polymer, specifically, a temperature slightly exceeding the second order transition temperature. At this time, as shown in FIG. 9 (B), the tube-shaped material 190 is heated in the mold 300 by being sent to the inside of the tube-shaped material 190 while being pressurized while extending the tube-shaped material 190 in the axial direction. The part 191 is brought into close contact with the molding surfaces 311 and 321 of the

movable molds

310 and 320. Then, a cooling liquid is circulated in a cooling pipe (not shown) provided in the mold 300 to cool the tubular material 190 to a secondary transition temperature or lower. Note that this cooling may be performed by simply leaving it alone without circulating the amount of the coolant. Thereafter, the inside of the tube-shaped material 190 is set to normal pressure, and the tube-shaped material 190 in which the basic outer shape of the balloon 100 is formed is removed from the mold 300. Then, unnecessary portions are appropriately cut at the distal end portion and the proximal end portion of the tubular material 190, whereby the balloon 100 having a basic outer shape as shown in FIG. 3A is manufactured.

The balloon 100 applicable to the balloon catheter 10 that enables the function of preventing the positional deviation from the stenosis N and the expansion by applying an appropriate pressure to the stenosis N by the above procedure is provided. It becomes possible to do.

As described above, the balloon catheter according to the present invention has been described through the embodiments. However, the present invention is not limited to the contents described in the embodiments, and can be appropriately modified based on the description of the scope of claims.

For example, although an example in which the present invention is applied to a rapid exchange type balloon catheter has been described, the present invention can also be applied to a so-called over-the-wire type balloon catheter. Even when applied to an over-the-wire type balloon catheter, the function capable of preventing the occurrence of displacement in the balloon is not impaired when performing a procedure for expanding the stenosis.

Further, for example, in the description of the embodiment, when the specified expansion pressure is reached, the outer diameter of the expansion effective portion is the outer diameter of the maximum outer diameter portion of the distal end side expansion portion and the maximum outer diameter portion of the proximal end side expansion portion. Although an example of a balloon configured to have the same diameter as the outer diameter has been shown, for example, when the specified expansion pressure is reached, the outer diameter of the expansion effective portion is the outer diameter of the maximum outer diameter portion of the distal side expansion portion and The balloon may be configured to be deformed to be larger than the outer diameter of the maximum outer diameter portion of the proximal end side expansion portion. Even in such a case, an appropriate pressure can be applied from the effective expansion portion to the stenosis portion after reaching the specified expansion pressure.

Further, for example, in the description of the embodiment, an example of a balloon in which the outer diameters of the distal end side expansion portion and the proximal end side expansion are formed to be substantially the same and the compliant characteristics are also formed to be substantially the same is described. As long as the function of preventing the positional deviation of the balloon can be exhibited, it is not particularly limited to such a configuration. For example, the outer diameter is different between one expansion part and the other expansion part, It is also possible to vary the compliant characteristics in the extended portion.

The configuration of each part of the balloon catheter includes at least a balloon having a predetermined shape including an expansion effective portion, a distal side expansion portion, and a proximal side expansion portion, and the distal side expansion portion when expanded and deformed. As long as it is configured to prevent the positional displacement of the balloon by the proximal end side expansion portion and further to apply a pressure to the stenosis portion via the effective expansion portion after reaching the specified expansion pressure, as appropriate It can be changed, and the configuration of the shaft, the hub, etc., the use of other additional members, the omission of the use, etc. can be appropriately performed.

This application is based on Japanese Patent Application No. 2014-066721 filed on March 27, 2014, the disclosure of which is incorporated by reference in its entirety.

10 balloon catheter,
20 shaft,
50 hubs,
100 balloons,
110 Extended effective part,
120, the distal end side extension,
121 maximum outer diameter,
122 slope,
123 contrast marker,
130, proximal extension,
131 Maximum outer diameter,
132 sloped part,
133 contrast markers,
190 Tubular material,
300 molds,
330 cavities,
B blood vessels,
N stenosis,
P ₁ specified expansion pressure.

Claims

A balloon catheter comprising an elongate shaft having flexibility, and an expandable and contractible balloon disposed on the distal end side of the shaft,
The balloon is
An expansion effective portion that expands the stenosis portion with expansion deformation;
A distal-side extension portion that is positioned on the distal end side and the proximal end side of the effective extension portion, and has a maximum outer diameter portion that has a larger outer diameter than each portion of the effective extension portion in a state before being expanded and deformed; and A proximal extension, and
Until the expansion effective portion reaches a specified expansion pressure that expands and deforms to a predetermined outer diameter, the outer diameter of the maximum outer diameter portion of the distal side expansion portion and the proximal end side than the outer diameter of each portion of the expansion effective portion It is deformed so that the outer diameter of the maximum outer diameter part of the expansion part becomes larger,
When the specified expansion pressure is reached, the outer diameter of each portion of the effective expansion portion is the same as the outer diameter of the maximum outer diameter portion of the distal end side expansion portion and the outer diameter of the maximum outer diameter portion of the proximal end expansion portion or A balloon catheter that is deformed to have the same diameter or more.
The distal end side expansion portion and the proximal end side expansion portion are characterized in that an expansion coefficient associated with an increase in expansion pressure after reaching the specified expansion pressure is relatively smaller than an expansion coefficient of the expansion effective section. The balloon catheter according to claim 1.
The compliant characteristics of the distal end side expanded portion and the proximal end side expanded portion are adjusted depending on the material, adjustment of the expansion ratio when the tubular member constituting the balloon is biaxially stretch blow molded in a mold, The balloon catheter according to claim 2, wherein the balloon catheter is adjusted by any one of a group consisting of adjustments by a suppressor that suppresses expansion deformation.
The balloon catheter according to any one of claims 1 to 3, further comprising a contrast marker indicating a position of a maximum outer diameter portion of the distal end side expansion portion and a maximum outer diameter portion of the proximal end expansion portion.
A method for producing the balloon according to any one of claims 1 to 4,
Arranging a tubular material in a mold having a cavity for molding the balloon;
A step of forming the balloon by applying an internal pressure and a stretching force to the tube-shaped material and expanding the tube-shaped material while heating the tube-shaped material in the mold.