JP6332922B2 - Balloon catheter and balloon manufacturing method used for balloon catheter - Google Patents

Description

  The present invention relates to a balloon catheter and a method for producing a balloon used for the balloon catheter.

  Percutaneous Coronary Intervention (PCI) is a safe and effective treatment method for improving blood flow on the peripheral side of a blood vessel by expanding the stenosis of the blood vessel when stenosis occurs in a blood vessel or the like. As is widely done.

  As a medical instrument for performing coronary vascular intervention, a balloon catheter (see, for example, Patent Document 1) is widely used. When performing a procedure using a balloon catheter, first, the balloon catheter is inserted into the blood vessel so that the balloon matches the stenotic site. Next, the stenotic site is expanded by injecting a pressurized fluid into the balloon to expand the balloon. After performing dilatation treatment, the balloon is deflated and the balloon catheter is removed from the blood vessel.

  In general, in a balloon catheter, the balloon surface is coated with a hydrophilic polymer so that the balloon surface has wettability when inserted into a blood vessel. As a result, the balloon becomes slippery in the blood vessel and can be smoothly inserted to the stenosis site.

  When the hydrophilic polymer deposited on the balloon substrate surface is repeatedly contacted with the blood vessel surface, it is peeled off from the balloon substrate surface. When the hydrophilic polymer is peeled off, the lubricity is lowered, so that the balloon is difficult to slip in the blood vessel. In order to suppress the separation of the hydrophilic polymer and continuously coat it, it is important to coat the balloon substrate surface with the hydrophilic polymer with high adhesion.

  As a method of coating the surface of a balloon substrate with a hydrophilic polymer with high adhesion, 1) a method of roughening the surface of the substrate by plasma or ultraviolet irradiation, and 2) providing a binder resin between the substrate and the hydrophilic polymer There are methods, etc.

Japanese Patent Application Laid-Open No. 06-296693

  However, the conventional method of coating the surface of the balloon substrate with the hydrophilic polymer with high adhesion is still insufficient in that the hydrophilic polymer is continuously retained on the balloon surface.

  In addition, when plasma or ultraviolet irradiation is performed on the substrate surface, it is necessary to coat the hydrophilic polymer within a short period of time when the substrate surface activated by these processes is in an activated state. Process is required.

  In addition, the method of providing a binder resin between the base material and the hydrophilic polymer needs to improve the adhesion between the base material and the binder resin, and the hydrophilic polymer and the binder resin, so that it becomes difficult to manufacture and performance. There is a high possibility of variations.

  The present invention has been made in view of the above points, and provides a method for producing a balloon, which can coat a hydrophilic base material having a good durability on the surface of a balloon substrate by an easy production process. Further, the present invention provides a balloon catheter suitable for coronary vascular intervention, which can be smoothly inserted up to a stenosis site, but is difficult to slip upon expansion at the stenosis site.

One aspect of the balloon catheter of the present invention is:
A catheter body;
A balloon that is provided at a distal portion of the catheter body and expands in a centrifugal direction of the catheter body by injecting fluid through a lumen in the catheter body;
A balloon catheter having
The balloon is
A first base material surface on which a first uneven surface is formed;
A second substrate surface on which a second concavo-convex surface having a concavo-convex shape different from the first concavo-convex surface is formed;
A hydrophilic polymer film that coats the first and second substrate surfaces;
Have
The concavo-convex shape of the second concavo-convex surface is a shape in which the hydrophilic polymer film is less likely to adhere or the hydrophilic polymer film is easily peeled off than the concavo-convex shape of the first concavo-convex surface. And
The balloon is
When not expanded, all or part of the second base material surface is folded so as not to be exposed on the surface .

One aspect of a method for producing a balloon used for the balloon catheter of the present invention is as follows.
Included in the concavo-convex surface is a mold having a concavo-convex surface having a first concavo- convex surface and a second concavo-convex surface having a concavo-convex shape having higher water repellency than the first concavo-convex surface on the surface. Transferring the first and second uneven surfaces to the surface of the balloon;
Coating a hydrophilic polymer film on the surface of the balloon onto which the first and second uneven surfaces have been transferred ;
As all or part of the second concave-convex surface is hidden, a step of folding the balloon,
Including

  According to the present invention, the balloon is formed with the first uneven surface having a high affinity with the hydrophilic polymer film and the second uneven surface with a low affinity with the hydrophilic polymer film. A balloon catheter suitable for coronary vascular intervention that can be smoothly inserted up to a stenotic site but is difficult to slip upon expansion at the stenotic site can be realized. In addition, since the uneven surface was formed on the surface of the balloon by transferring the uneven surface from the mold having the uneven surface formed on the surface, a hydrophilic polymer with good durability can be coated on the surface of the balloon substrate by an easy manufacturing process. become able to.

Schematic which shows the whole structure of the balloon catheter which concerns on embodiment The figure which uses for description of the manufacturing method of the balloon by embodiment The figure which shows the mode of transfer of the uneven surface by embodiment 4A is a view showing a state where the balloon is expanded, and FIG. 4B is a view showing a state where the balloon is folded. FIG. 5A is a cross-sectional view showing a state of a first uneven surface and a hydrophilic polymer film coated thereon, and FIG. 5B is a cross section showing a state of a second uneven surface and a hydrophilic polymer film coated thereon. Figure The figure which shows the balloon (expanded state) of other embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Overall configuration>
FIG. 1 is a diagram showing a configuration example of a balloon catheter according to an embodiment of the present invention. The balloon catheter 100 includes a hub 110, a balloon 120, a proxy shaft 130, a distal shaft 140, and a guide wire lumen tube 150 as main bodies.

  The hub 110 is placed at the hand of a doctor who operates the balloon catheter 100 in angioplasty. The hub 110 is configured to be connectable to a pressure application device (not shown) such as an inflator that supplies a high-pressure fluid. The proximal shaft 130 is joined to the hub 110 so as to be in fluid communication, and extends distally. Further, a distal shaft 140 is joined to the distal side so as to be in fluid communication. A balloon 120 is joined to the distal side of the distal shaft 140. The proxy shaft 130 and the distal shaft 140 form a flow path for supplying a high-pressure fluid into the balloon 120.

  The distal end of the balloon 120 surrounds the outer peripheral surface of the guide wire lumen tube 150 and is joined to the outer peripheral surface. Thereby, the high-pressure fluid supplied to the balloon 120 stays inside the balloon 120, and the balloon 120 expands. That is, before the high-pressure fluid is supplied to the inside, the balloon 120 is folded so as to have substantially the same dimension as the outer diameter of the distal shaft 140 and is provided so as to be in close contact with the outer peripheral surface on the distal side of the guide wire lumen tube 150. It has been. When the high-pressure fluid is supplied to the inside of the balloon 120, the balloon 120 expands by expanding the fold. In FIG. 1, the balloon 120 is shown in an expanded state.

  The guide wire lumen tube 150 penetrates the distal shaft 140 so that the inner shaft (guide wire lumen) forms a coaxial or biaxial double tube structure with the distal shaft 140 without communicating with the flow path. It is provided through the balloon 120. The opening on the proximal side of the guide wire lumen tube 150 is disposed in the vicinity of the joint between the proxy shaft 130 and the distal shaft 140, and the opening on the distal side of the guide wire lumen tube 150 is the tip of the balloon 120. It is arranged further to the distal side than the part. The proximal opening is provided as a guide wire port 170 that is an insertion / extraction port for the guide wire 160.

<Method for producing balloon 120>
A method for manufacturing the balloon 120 according to the present embodiment will be described with reference to FIG.

  First, in the first step, as shown in FIG. 2A, a fine uneven surface 201 is formed on the surface of a mold 200. This step can be performed by known processes such as machining such as cutting, press precision casting, etching, electric discharge machining, and electroplating.

  Next, in the second step, as shown in FIG. 2B, the uneven surface 201 of the surface of the mold 200 is transferred to the surface of the balloon substrate 300, thereby forming the uneven surface 301 on the surface of the balloon substrate 200. . The balloon base material 300 is preferably a material having a certain degree of flexibility. For example, polyurethane, polyurethane elastomer, silicone rubber, synthetic natural rubber, natural rubber, styrene / butadiene rubber, butadiene rubber, butyl rubber, ethylene / propylene rubber, Polyisopropylene, nitrile rubber, acrylic rubber, fluorine rubber, polyamide, polyamide elastomer, polyester elastomer, olefin elastomer, polyvinyl chloride, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ionomer, fluorine resin, etc. Or a combination thereof.

  FIG. 3 shows how the uneven surface is transferred from the mold 200 to the balloon substrate 300. As shown in FIG. 3A, the balloon base material 300 is disposed inside the mold 200 disposed so that the fine uneven surface 201 faces inward, and the balloon base material 300 is placed in an atmosphere of 80 to 180 ° C. Nitrogen gas is blown to expand the balloon base material 300, whereby the balloon base material 300 is pressed against the mold 200 to perform blow molding. As a result, the fine uneven surface 201 of the mold 200 is transferred to the balloon substrate 300 to form the uneven surface 301. 3B is a cross-sectional view showing a cross section A-A ′ of FIG. 3A. Incidentally, the thickness of the balloon substrate 300 is 10-50 μm, and the height of the unevenness is on the order of very small with respect to this thickness.

  Next, in the third step, as shown in FIG. 2C, the hydrophilic polymer film 400 is coated on the uneven surface 301 of the balloon base material 300. The hydrophilic polymer film 400 is based on, for example, a maleic anhydride copolymer. The balloon thus formed is used as the balloon 120 in FIG.

  As described above, according to the manufacturing method of the present embodiment, the fine uneven surface 301 is formed on the surface of the balloon substrate 300 by blow molding using the mold 200, and the hydrophilic polymer is formed on the fine uneven surface 301. The membrane 400 was coated.

  Thus, the balloon base material 300 can be manufactured by an easy manufacturing process as compared with the case where the surface of the balloon base material is roughened by plasma or ultraviolet irradiation, or when the binder resin is provided between the balloon base material and the hydrophilic polymer. Thus, the hydrophilic polymer film 400 can be coated on the surface of the balloon catheter 100, and the balloon catheter 100 having good slipperiness in the blood vessel can be easily manufactured.

  In other words, in the method of roughening the surface of the balloon substrate by plasma or ultraviolet irradiation, it is necessary to coat the hydrophilic polymer within a short period of time when the substrate surface activated by these processes is in an activated state. For this reason, the manufacturing process according to the present embodiment increases the restrictions on the process, but the uneven surface 301 transferred from the mold 200 is semipermanently maintained, so that the hydrophilic polymer film 400 is maintained. It is not necessary to perform coating in a short time, and there are few process restrictions. Furthermore, since the uneven surface 301 is semipermanently maintained, even if the hydrophilic polymer film 400 is peeled off, the balloon base material 300 is repeatedly applied only by coating the hydrophilic polymer film 400 again. It can be used repeatedly. Furthermore, there is an advantage that the balloon base material 300 is less likely to be damaged than the plasma or ultraviolet irradiation, and the balloon base material 300 is not easily deteriorated.

  Compared with the case where a binder resin is provided between the balloon substrate and the hydrophilic polymer film, it is not necessary to add a new material, the film thickness does not increase, the number of processes is small, and it is technically simple. There are a number of advantages. In addition, since there is no binder resin between the balloon base material and the hydrophilic polymer film, the variation in adhesion between the balloon base material and the hydrophilic polymer film is reduced, and it can be used for a longer time. I can expect that.

<Detailed configuration of balloon>
The surface of the balloon 120 of the present embodiment is divided into a first base material surface 121 and a second base material surface 122 as shown in FIG. 4A. A first uneven surface B <b> 1 is formed on the first base material surface 121. On the second base material surface 122, a second uneven surface B2 is formed. In the case of the present embodiment, the second uneven surface B2 is formed over the long axis direction of the balloon catheter 100 (FIG. 1). The first and second uneven surfaces B1 and B2 are coated with a hydrophilic polymer film 400 (FIGS. 5A and 5B).

  The concavo-convex shape of the second concavo-convex surface B2 is such that the hydrophilic polymer film 400 is less likely to adhere than the concavo-convex shape of the first concavo-convex surface B1, or the hydrophilic polymer film 400 is easy to peel off. .

  FIG. 5A is a cross-sectional view showing a state of the first uneven surface B1 and the hydrophilic polymer film 400 coated thereon, and FIG. 5B shows the second uneven surface B2 and the hydrophilic polymer film 400 coated thereon. It is sectional drawing which shows a mode. As can be seen from the figure, the second uneven surface B2 (FIG. 5B) is less likely to adhere to the hydrophilic polymer film 400 than the first uneven surface B1 (FIG. 5A), or the hydrophilic polymer film 400. The shape is easy to peel off.

  In the case of the present embodiment, as can be seen from FIG. 5, the ratio of the height of the convex portion to the interval between the convex portions of the concave and convex surface is the first in the second concave and convex surface B2 (FIG. 5B). It is larger than the uneven surface B1 (FIG. 5A). Thereby, about the 1st uneven surface B1, since the hydrophilic polymer film 400 penetrates into the back of an uneven | corrugated recessed part, the hydrophilic polymer film 400 tends to adhere to a base-material surface, or a hydrophilic polymer film 400 becomes difficult to peel from the substrate surface. On the other hand, as for the second uneven surface B2, the hydrophilic polymer film 400 does not penetrate deeply into the recesses and recesses of the unevenness, so that the hydrophilic polymer film 400 is difficult to adhere to the substrate surface or is hydrophilic. The polymer film 400 is easily peeled off from the substrate surface.

  Here, in general, if the unevenness appearing at the same pitch, the greater the unevenness height difference, the more water repellent (that is, the hydrophilic polymer film 400 becomes difficult to attach), and the unevenness height difference decreases. It becomes hydrophilic (that is, the hydrophilic polymer film 400 is easily attached). Further, if the difference in height of the unevenness is the same, the water repellency is increased as the pitch at which the unevenness appears is decreased, and the hydrophilicity is increased as the pitch at which the unevenness is increased. In the present embodiment, in consideration of this, the first and second uneven surfaces B1 and B2 are formed.

  The first and second uneven surfaces B1 and B2 are preferably formed by blow molding using the above-described mold. By using the manufacturing method described above, a complicated uneven shape (in this embodiment, there are two types of uneven surfaces) can be accurately and easily created.

  In order to form the first and second uneven surfaces B1 and B2 on the balloon base material, in addition to the unevenness corresponding to the first uneven surface B1, the second uneven surface is previously added to the mold 200 (FIG. 2A). Concavities and convexities corresponding to B2 are formed, and this is only transferred to the balloon substrate 200 by blow molding as described above. By the way, in the method of forming an uneven surface by irradiation, the shape of the uneven surface is affected by the bulging condition during processing of the balloon, and masking is required, so it is easy to accurately and easily form a complicated uneven shape on the balloon surface. Is difficult to form.

  4A shows a state where the balloon 120 is expanded, and FIG. 4B shows a state where the balloon 120 is not expanded. Prior to expansion, the balloon 120 is folded so that the second base material surface 122 (second uneven surface B2) does not appear on the surface of the balloon 120 (FIG. 4B). The material surface 122 (second uneven surface B <b> 2) is exposed on the surface of the balloon 120. In addition, although it is preferable to fold so that the 2nd base material surface 122 (2nd uneven surface B2) may be completely hidden, as shown to FIG. 4B, the 2nd base material surface 122 (2nd uneven surface B2) May be folded so that it is not completely hidden but only part of it is hidden.

  In order to produce such a balloon, first, a balloon base material having the first and second uneven surfaces B1 and B2 is prepared by blow molding using a mold, and then the entire surface of the balloon base material is uniformly hydrophilic. The conductive polymer film 400 may be coated, and then the balloon 120 may be folded so that the second uneven surface B2 is hidden. Various folding methods proposed by conventional balloon catheters, such as folding in a spiral shape, can be applied as the method of folding the balloon. In short, as long as the second uneven surface B2 is hidden. Good.

  In addition, when a drug is applied to the surface of the balloon, the surface on which the drug is applied is preferably the first uneven surface B1 having a high affinity with the hydrophilic polymer. By doing in this way, since it becomes easy for a chemical | medical agent to stay on the balloon surface, it becomes possible to deliver a chemical | medical agent to a stenosis site | part (affected part).

  When the balloon catheter 100 to which the balloon 120 according to the present embodiment is attached is used to perform dilatation treatment of a stenosis site, first, the deflated balloon 120 as shown in FIG. The inner balloon 120 is moved to the stenosis site. At this time, the first concavo-convex surface B1 exposed on the surface of the balloon 120 has high affinity with the hydrophilic polymer film 400 (that is, the force for holding the hydrophilic polymer film 400 is strong). The balloon 120 reaches the stenotic site while smoothly sliding in the blood vessel with the hydrophilic polymer film 400 interposed therebetween. Next, the balloon is expanded by injecting a pressurized fluid into the balloon 120. Then, the second uneven surface B2 having a low affinity with the hydrophilic polymer film 400 appears and comes into contact with the wall surface of the blood vessel, so that the balloon 120 continues to expand in a state in which it is difficult to slip in the blood vessel. As a result, since the balloon 120 is expanded without deviating from a desired stenosis site, coronary vascular intervention can be suitably performed.

  Using a high-pressure balloon (a high-pressure balloon is a balloon with a pressure resistance of 20 atmospheres compared to a general balloon with a pressure resistance of up to 14 atmospheres), an attempt is made to expand a hard blood vessel part that has caused a calcified lesion. In this case, in addition to the technology that smoothly slides the balloon to the vascular site, the high pressure resistant balloon slides at the expanded position, so that the vascular position different from the vascular position to be expanded is expanded. Technology to prevent this is necessary. Conventionally, the above-described balloon slipping and slippage prevention have been realized by controlling the coating amount of the hydrophilic polymer film applied to the balloon expansion effective part by masking or the like. On the other hand, in the present embodiment, the affinity for the hydrophilic polymer on the surface of the balloon base material is controlled by controlling the shape of the irregularities transferred to the balloon. Therefore, it is possible to easily and accurately control which position on the balloon surface is easy to slide and which position is difficult to slide.

  In the above-described embodiment, as shown in FIG. 4A, the case where the second uneven surface B2 (that is, the second base material surface 122) is formed over the long axis direction of the balloon catheter 100 has been described. The present invention is not limited to this. As shown in FIG. 6, the second uneven surface B <b> 2 (that is, the second base material surface 122) may be formed in a direction orthogonal to the major axis direction of the balloon catheter 100 (that is, the circumferential direction of the balloon 120). . Further, the second uneven surface B2 may be formed in a spiral shape. The position on the balloon where the second uneven surface B2 is to be formed may be in accordance with how the balloon is folded. That is, the second uneven surface B2 is preferably formed at a position that is hidden when folded. In other words, the balloon may be folded so that the surface on which the second uneven surface B2 is formed is hidden. Only a part of the surface on which the second uneven surface B2 is formed may be hidden, but it is preferable that the entire surface is hidden if possible.

  In the above-described embodiment, the case where the unevenness of the mold 200 is transferred to the balloon base material 300 by blow molding has been described. However, the present invention is not limited thereto, and the unevenness may be transferred by, for example, vacuum forming. Good.

  The above-described embodiments are merely examples of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed as being limited thereto. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

  The present invention can be applied to a balloon catheter and a method for manufacturing a balloon used for the balloon catheter.

DESCRIPTION OF SYMBOLS 100 Balloon catheter 120 Balloon 121 1st base material surface 122 2nd base material surface 200 Mold 201, 301 Concavity and convexity 300 Balloon base material 400 Hydrophilic polymer film B1 1st uneven surface B2 2nd uneven surface

Claims (4)

A catheter body;
A balloon that is provided at a distal portion of the catheter body and expands in a centrifugal direction of the catheter body by injecting fluid through a lumen in the catheter body;
A balloon catheter having
The balloon is
A first base material surface on which a first uneven surface is formed;
A second substrate surface on which a second concavo-convex surface having a concavo-convex shape different from the first concavo-convex surface is formed;
A hydrophilic polymer film that coats the first and second substrate surfaces;
Have
The concavo-convex shape of the second concavo-convex surface is a shape in which the hydrophilic polymer film is less likely to adhere or the hydrophilic polymer film is easily peeled off than the concavo-convex shape of the first concavo-convex surface. And
The balloon is
In an unexpanded state, all or part of the second base material surface is folded so as not to be exposed on the surface,
Balloon catheter. The second substrate surface is higher in water repellency than the first substrate surface.
The balloon catheter according to claim 1. The ratio of the height of the convex portion to the interval between the convex portions of the concave and convex surface is such that the second concave and convex surface of the second base material surface is larger than the first concave and convex surface of the first base material surface. ,
The balloon catheter according to claim 1 or 2. A method of manufacturing a balloon used for a balloon catheter,
Included in the concavo-convex surface is a mold having a concavo-convex surface having a first concavo- convex surface and a second concavo-convex surface having a concavo-convex shape having higher water repellency than the first concavo-convex surface on the surface. Transferring the first and second uneven surfaces to the surface of the balloon;
Coating a hydrophilic polymer film on the surface of the balloon onto which the first and second uneven surfaces have been transferred ;
As all or part of the second concave-convex surface is hidden, a step of folding the balloon,
A method for manufacturing a balloon comprising :

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