JP6788964B2 - Catheter Balloon manufacturing method and balloon catheter - Google Patents

Description

The present invention relates to a manufacturing method and balloon catheters of the catheter balloon.

Balloon catheters are widely used for the purpose of expanding stenotic sites of blood vessels such as coronary arteries to improve blood flow.

The balloon catheter has a balloon on the distal side away from the hand side. The balloon of the balloon catheter before use is folded to a small diameter so as not to interfere with insertion into the blood vessel. Then, the balloon catheter is inserted into the blood vessel, the balloon is aligned with the stenosis site, and the expansion fluid is injected from the hand side to expand the balloon. By doing so, the stenotic site is dilated and the blood flow is improved. After the diastolic treatment, the injected fluid is withdrawn to compress the balloon under reduced pressure, the balloon is refolded, and the balloon catheter is withdrawn from the blood vessel.

Here, as a method of folding the balloon, the balloon is wound around the catheter body in a small diameter and heated, and the balloon is memorized by the heating to memorize the folded shape, and even when refolding (rewrapping), the balloon is heated by decompression. It is common to shrink the shape to a shape close to the memorized folding shape.

However, when the balloon is heated, the balloon becomes hard, and when it is refolded (rewrapped), it is not folded neatly and tends to have a stiff irregular shape.

If the balloon is stiff and cannot be folded neatly, it is not preferable because the balloon catheter is easily caught in the blood vessel or the like when it is pulled out from the blood vessel.

In addition, one balloon catheter may be used to perform diastolic treatment for a plurality of stenotic sites in the same patient, in which case the balloon dilation and contraction are repeated. If the balloon contracts in a stiff and irregular shape during this contraction, it may be difficult to insert the balloon into the next stenotic site to be treated for dilatation.

Here, Patent Document 1 discloses a balloon made of a material having a rigidity different from that of the base material of the balloon, in which muscles extending in the longitudinal direction are arranged at a plurality of locations in the circumferential direction.

Further, Patent Document 2 discloses a balloon in which rigidity is increased by heating and muscles extending in the longitudinal direction are formed at a plurality of locations in the circumferential direction.

International Publication WO2009 / 080321 JP-A-2014-57793

Here, in the case of the balloon disclosed in Patent Document 1 above, which is made of a material having a rigidity different from that of the membrane made of the base material of the balloon and in which muscles extending in the longitudinal direction are arranged at a plurality of locations in the circumferential direction, the balloon The membrane made of the base material and the streaks are joined to each other only with a very thin balloon thickness. For this reason, the joint between the membrane and the streak made of different materials may be torn.

Further, in the case of the balloon disclosed in Patent Document 2 described above, in which the rigidity is increased by heating and the streaks extending in the longitudinal direction are formed at a plurality of locations in the circumferential direction, many manufacturing steps are required and the cost is increased. Not preferable from the viewpoint.

In view of the above circumstances, the present invention provides a balloon catheter having a highly reliable balloon that can be manufactured relatively easily and has excellent refoldability (rewrapability), and a balloon for the balloon catheter. The purpose.

The balloon catheter of the present invention that achieves the above object is
A balloon catheter having a catheter body and a balloon provided at the distal portion of the catheter body and expanding in diameter by injecting fluid through the catheter body.
The balloon has a double-tube shape in which a first film made of a first material and a second film made of a second material having a relative rigidity different from that of the first film are in close contact with each other. The second membrane is characterized by having a slit extending in a direction containing a component in the longitudinal direction of the catheter body.

The balloon catheter of the present invention has a balloon having a double tube shape and composed of a first membrane and a second membrane that are in close contact with each other. Therefore, the first film and the second film are joined to each other on a wide surface. Therefore, the risk of dissociation between the first film and the second film can be sufficiently suppressed. Further, even if dissociation occurs, the balloon does not rupture, and high reliability is ensured.

Further, in the balloon of the balloon catheter of the present invention, a slit is formed in the second membrane. Therefore, it is easy to have a fold habit, and sufficient refoldability (rewrap property) is ensured. In addition, this balloon can be manufactured relatively easily, which is advantageous in terms of cost.

Here, in the balloon catheter of the present invention, it is preferable that the second material is a material having a relatively high rigidity as compared with the first material.

When the slit is provided in a material having high rigidity, the difference in rigidity between the slit portion of the balloon and the portion other than the slit becomes large, and the refoldability (rewrap property) is further improved.

Further, in the balloon catheter of the present invention, it is preferable that the slits are formed at a plurality of positions of the second membrane at equal intervals in the circumferential direction surrounding the catheter body.

The balloon of a balloon catheter usually has three points of 120 degrees in the circumferential direction protruding radially in a wing shape, and the three wing-shaped parts are folded into a rounded shape. Therefore, it is expected that the refoldability will be further improved by forming a plurality of streaks such as three streaks.

Further, in the balloon catheter of the present invention, it is preferable that the second membrane is formed on the outer peripheral surface side of the first membrane.

A slit is formed in the second film. Therefore, by forming the second film on the outer peripheral surface side of the first film, it becomes easy to inspect that the slit is correctly formed. Further, the slit may be formed at the time of extrusion molding, but may be formed by laser processing or the like after extrusion molding. That is, by forming the second film on the outer peripheral surface side of the first film, the range of selection of the slit forming method can be expanded.

Further, the balloon of the present invention that achieves the above object is
A balloon provided at the distal part of the catheter body and expanding in diameter by injecting fluid through the catheter body.
A first film made of a first material and a second film made of a second material having a relative rigidity different from that of the first film have a double-tube shape in which they are in close contact with each other. The membrane of No. 2 is characterized in that a slit extending in a direction containing a component in the longitudinal direction of the catheter body is formed.

Here, in the balloon catheter and the balloon of the present invention, the slit formed in the second membrane is a slit extending in a direction containing a component in the longitudinal direction of the catheter body. In other words, the slit may extend linearly in the longitudinal direction of the catheter body parallel to the catheter body, or may be a spiral slit extending in the longitudinal direction of the catheter body while orbiting the catheter body. Good. Further, in the case of a spiral slit, the slit may be a slit that orbits the catheter body more than once, but is not limited to this, and the start point and the end point of the slit in the longitudinal direction of the catheter body. The catheter body may be orbited by an angle smaller than one orbit in the direction of orbiting the catheter body.

The balloon, which has been expanded and then contracted, gradually enters the narrow or narrowed portion of the blood vessel from one of the longitudinal directions of the balloon toward the other. When the spiral slit is formed, it is easy to fold the balloon in order from one to the other in the longitudinal direction to a smaller diameter, and the refoldability (relap property) is further improved as compared with the case where a straight streak is provided in the longitudinal direction. improves.

When this spiral streak is provided, the number of streaks may be a plurality of streaks such as three in the circumferential direction, but the number of streaks may be only one depending on the pitch of the spiral. ..

Further, the balloon constituting the balloon catheter of the present invention and the balloon of the present invention may have a double tube shape composed of the above-mentioned first membrane and the second membrane, for example, a triple tube shape, etc.
It may further have a component other than the double tube shape.

According to the above invention, it is possible to provide a balloon catheter having a highly reliable balloon having excellent refoldability and a balloon for the balloon catheter.

It is a schematic diagram of the whole structure of the balloon catheter as the 1st Embodiment of this invention. FIG. 1 is a cross-sectional view showing the internal structure of a balloon catheter in which the shaft portion shown as a whole is cut in the longitudinal direction. It is a schematic diagram which showed the cross section of the balloon along the arrow AA shown in FIG. FIG. 3 is a schematic view showing a cross section of the balloon shown in FIG. 3 in a withered shape after being expanded once. It is a schematic diagram which showed the cross section of the balloon which concerns on 2nd Embodiment of this invention. It is a schematic diagram which showed the cross section of the balloon which concerns on 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.

FIG. 1 is a schematic diagram of the overall configuration of a balloon catheter as the first embodiment of the present invention.

The balloon catheter 100 has a catheter body 10 and a balloon 20.

The catheter body 10 has a hub 11, a proximal shaft 12, and a distal shaft 13. The proximal shaft 12 has a single tube structure with an outer tube, and the distal shaft 13 has a double tube structure with an outer tube and an inner tube. These structures will be described later with reference to FIG. A guide wire insertion port 14 for inserting the guide wire 30 is formed at the boundary between the proximal shaft 12 and the distal shaft 13.

The hub 11 is placed in the hands of a doctor who operates the balloon catheter 100. The balloon 20 is provided on the distal side away from the hub 11.

The hub 11 is connected to an deflator (not shown) or the like used for supplying and discharging a fluid. The fluid supplied to the hub 11 is supplied to the balloon 20 through the proximal shaft 12 and the distal shaft 13. In FIG. 1, the balloon 20 is already shown in an expanded shape, but the balloon 20 is folded so that it can be wound into a small diameter when the balloon catheter 100 is not in use. While being guided by the guide wire 30, the balloon catheter 100 is inserted into the blood vessel until the balloon 20 reaches the narrowed portion of the blood vessel. Then, in that state, the balloon expands by receiving the supply of fluid and expands the blood vessel. After that, the fluid is discharged, and the balloon 20 has a deflated shape. When the deflated balloon 20 reaches the small diameter portion of the blood vessel, it is refolded (rewrapped).

FIG. 2 is a cross-sectional view showing the internal structure of the balloon catheter, which is shown in FIG. 1 as a whole, by cutting the shaft portion in the longitudinal direction.

The proximity shaft 12 has a metal tube 15 connected to the hub 11 shown in FIG. 1 and an outer tube 16 joined to the distal end of the metal tube 15. A polyamide resin, a urethane resin, a polyethylene resin, or the like is used for the outer tube 16.

The distal shaft 13 has a double-tube structure consisting of an outer tube 16 further extending from the proximal shaft 12 and an inner tube 17 arranged inside the outer tube 16. The guide wire 30 shown in FIG. 1 is inserted through the inner tube 17. The guide wire 30 is inserted from the guide wire insertion port 14 provided at the boundary between the proximal shaft 12 and the distal shaft 13, passes through the inner tube 17, and extends the guide wire at the distal end of the inner tube 17. It extends further distally from port 171. Like the outer tube 16, the inner tube 17 can be formed of a polyamide resin, a urethane resin, a polyethylene resin, or the like.

The proximal end 201 of the balloon 20 was joined to the distal end 162 of the outer tube 16 all around, and the distal end 202 of the balloon 20 was slightly lower than the guide wire extension port 171 of the inner tube 17. It is joined to the position (position according to the proximal side) over one round. Similar to FIG. 1, FIG. 2 shows a balloon 20 in an already expanded state, but the balloon 20 has a diameter substantially equal to the outer diameter of the outer tube 16 when not in use. , It is folded so as to be wrapped around the inner tube 17.

The fluid supplied from the hub 11 shown in FIG. 1 is injected into the balloon 20 through the inside of the outer tube 16 and the outside of the inner tube 17 to expand the balloon 20.

A metal core wire 18 is arranged in the outer tube 16. The proximal end of the core wire 18 is welded to the metal tube 15 and extends to a position in front of the balloon 20 of the distal shaft 13. The core wire 18 plays a role of preventing kink and buckling of the catheter while maintaining the flexibility of the tip of the catheter.

FIG. 3 is a schematic view showing a cross section of the balloon along the arrows AA shown in FIG. FIG. 3 shows a cross section of an expanded balloon.

The balloon 20 has a double-tube structure in which the first film 21 and the second film 22 are in close contact with each other. Here, the first material forming the first film 21 and the second material forming the second film 22 have different rigidity from each other. In the present embodiment, the outer second film 22 is formed of a material having higher rigidity than the inner first film 21.

In the case of the present embodiment, the outer peripheral surface of the inner first film 21 and the inner peripheral surface of the outer second film 22 are joined over the entire circumference and the entire length except for the portion of the slit 23 described below. Therefore, although the first film 21 and the second film 22 are made of different materials, they have a structure that is difficult to dissociate. Even if it dissociates, there is less risk of accidents such as rupture of the balloon as compared with the structure in which different materials are arranged in the circumferential direction as disclosed in Patent Document 1 described above.

Here, the slit 23 extends linearly in parallel with the catheter main body 10 in the longitudinal direction in which the catheter main body 10 (see FIGS. 1 and 2) extends. Alternatively, the slit 23 may be a slit having a spiral shape extending in the longitudinal direction of the catheter body 10 while orbiting the catheter body 10. When the spiral slit 23 is formed, it is expected that the refoldability (rewrap property) is further improved as compared with the case where the slit is formed linearly in the longitudinal direction. Further, in the case of a spiral slit, it is not necessary to have a plurality of slits such as three as shown in FIG. 3, and only one slit may be used depending on the pitch of the spiral and the like.

FIG. 4 is a schematic view showing a cross section of the balloon shown in FIG. 3 in a withered shape after being expanded once.

In the withered shape shown in FIG. 4, the slit 23 is located at the apex of the three blade-shaped films 21 and 22 extending. Before use, the balloon 20 has three blades that are further folded into a rounded shape, and has an outer diameter that is substantially the same as the outer diameter of the outer tube 12 (see FIG. 2).

When the deflated balloon 20 tries to pass through a narrow part of a blood vessel after being expanded once, the wing-shaped part is pushed by the inner wall of the blood vessel to be further rounded and easily passes through. be able to. As described above, since the balloon 20 in the present embodiment has the slit 23 formed, the balloon 20 is easily folded along the slit 23 and is excellent in refoldability.

Further, in manufacturing the balloon 20 having the shape shown in FIGS. 3 and 4, two colors of the first material forming the first film 21 and the second material forming the second film 22 are used. Extrusion molding is performed, followed by blow molding. The slit 23 may have an extrusion mold as a mold structure in which such a slit 23 is formed. Alternatively, the die may be extruded into a simple double tube structure without the slit 23, and the slit 23 may be formed by irradiating a laser beam or the like after extrusion molding. Further, in order to form the spiral slit 23 by extrusion molding, extrusion molding may be performed while rotating the mold or the extruded two-color material.

Hereinafter, other embodiments will be described with reference to the cross-sectional shape of the balloon. In any of the following embodiments, the shape of the slit in the longitudinal direction is the same as that of the above-described first embodiment. Further, in the following description of the embodiment, for the sake of clarity, the same reference numerals as those in FIG. 3 in the above-described first embodiment will be added.

FIG. 5 is a schematic view showing a cross section of the balloon according to the second embodiment of the present invention.

The balloon 20 of the second embodiment shown in FIG. 5 has a double-tube shape in which the outer first film 21 and the inner second film 22 are in close contact with each other. In the case of this second embodiment, the inner second film 22 is made of a material having higher rigidity than the outer first film 21. Then, in the case of this second embodiment, three slits 23 are formed in the inner second film 22 at equal intervals in the circumferential direction. As described above, the shape of the slit 23 in the longitudinal direction in the second embodiment may be a linear shape or a spiral shape. In the case of the balloon 20 of the second embodiment shown in FIG. 5, it is difficult to form the slit 23 by laser processing, and the slit 23 is formed by the shape of the extrusion mold.

As shown in FIG. 5, the slit 23 may be formed in the inner film.

FIG. 6 is a schematic view showing a cross section of a balloon according to a third embodiment of the present invention.

In the balloon 20 of the third embodiment shown in FIG. 6, the inner first film 21 and the outer second film 22 are in close contact with each other, as in the case of the first embodiment (see FIG. 3) described above. It has a double-tube shape. In the case of this third embodiment, the outer second film 22 is made of a material having higher rigidity than the inner first film 21. In the case of the third embodiment, the slit 23 is formed in the outer second film 22 as in the case of the first embodiment. The difference from the first embodiment is that, in the case of the first embodiment, as shown in FIG. 3, the slit 23 has a shape in which the second film is removed over the entire thickness in the thickness direction. In the case of the third embodiment, the groove-shaped slit 23 of the second film 22 leaving a part on the first film 21 side is formed in the thickness direction.

The groove-shaped slit 23 as shown in the third embodiment may be formed in consideration of the thickness and rigidity of the first film 21 and the second film 22 and the refoldability (rewrap property). ..

Although the example of forming the slit 23 in the film having the higher rigidity has been described here, the slit 23 may be formed in the film having the lower rigidity. Even in that case, the folding property can be changed between the slit portion and the non-slit portion.

10 Catheter body 11 Hub 12 Outer tube 13 Distal shaft 14 Guide wire insertion port 15 Metal tube 16 Outer tube 17 Inner tube 18 Core wire 20 Balloon 21 First film 22 Second film 23 Slit 100 Balloon catheter 171 Guide wire extension port 201 Proximal end 202 Distal end

Claims (2)

A method for manufacturing catheter balloons
The first material and the second material having a relatively high rigidity as compared with the first material are extruded in two colors, and the first film made of the first material and the second material are formed. The process of forming a double tube in which the second film made of the same material is in close contact with each other,
It has a step of blow molding the double tube.
In the step of forming the double tube, a mold having a structure in which a slit extending in a direction containing a component in the longitudinal direction of the balloon is formed in the second film is used.
A method for manufacturing a catheter balloon. A claim characterized in that in the step of forming the double tube, a spiral slit is formed in the second film by extrusion molding while rotating a mold or an extruded two-color material. The method for manufacturing a catheter balloon according to 1.

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