JP6162932B2 - Balloon catheter and balloon catheter manufacturing method - Google Patents

Description

  The present invention relates to a balloon catheter and a method for manufacturing a balloon catheter.

  Coronary artery intervention (PCI: Percutaneous Coronary Intervention) 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.

  In addition, treatment methods for expanding the stenosis site and avoiding restenosis are being established. For example, a technique for reducing the rate of restenosis has been proposed by using a balloon catheter whose outer surface is coated with a drug that prevents restenosis (see, for example, Non-Patent Document 1). When performing treatment using such a balloon catheter, first, the balloon catheter is inserted into a blood vessel, and the balloon is matched with a stenosis site (hereinafter, a treatment site). The balloon is then inflated to release the drug coated on the surface of the balloon to the treatment site. After the drug is released to the treatment site, the balloon is deflated and the balloon catheter is removed from the body.

  In addition, a technique has been proposed in which a balloon of a balloon catheter is manufactured using a porous elastomer material (see, for example, Patent Document 1). In the technique described in Patent Document 1, a plurality of cavities are dispersedly formed in the balloon. Drugs are embedded in the cavities. When performing treatment using such a balloon catheter, the balloon catheter is inserted into the blood vessel so that the balloon matches the treatment site. Then, the balloon is inflated, so that the drug is squeezed out from the cavity that is expanded by the inflation, and the drug is released to the treatment site. This makes it possible to directly deliver a drug of a type or concentration that cannot be used by other methods (for example, injection, taking, etc.) to the treatment site.

Japanese Patent No. 4436761

B Braun's “SeQuent Pleasing” catalog

  However, in the case of a balloon coated with a drug on the surface, the amount of drug that can be delivered directly to the treatment site is reduced because the coating peels off or melts before the balloon catheter reaches the treatment site. There was a problem.

  In the technique described in Patent Document 1, since the drug and the balloon are integrally formed, the more the balloon is inflated in order to release the drug, the smaller the wall thickness of the balloon is. Depending on the situation, the balloon could be broken. Therefore, in practice, it is necessary to inflate the balloon to such an extent that the balloon cannot be broken. However, if the balloon is not sufficiently inflated, the drug is released only from the surface of the balloon, and the drug remains inside the balloon. Therefore, the necessary amount of drug cannot be delivered to the treatment site.

  An object of this invention is to provide the balloon catheter which can deliver a required quantity of chemical | medical agents with respect to a treatment site | part, and the manufacturing method of a balloon catheter.

The balloon catheter according to 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 a fluid through a lumen in the catheter body;
A porous resin film formed on the outer peripheral surface of the balloon and cracked when the balloon expands in diameter ;
Have
The hole of the porous resin film is a starting point of the crack of the porous resin film when the balloon is expanded, and is a region other than the hole of the porous resin film that is a cracked portion when the balloon is expanded. the drug is mixed.

A method for manufacturing a balloon catheter according to the present invention includes:
A first step of forming a film of a mixed solution in which a drug, a resin and a solvent are mixed on an outer peripheral surface of a balloon formed in a distal portion of the catheter body;
The solvent is removed from the film of the mixed liquid formed on the outer peripheral surface of the balloon by a vacuum freeze-drying method , the film of the mixed liquid has a hole that becomes a starting point of a crack when the balloon is expanded, and A second step of changing the region other than the holes into a porous resin film that becomes a cracked portion when the balloon is expanded ,
including.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a balloon catheter and a balloon catheter which can deliver a required quantity of chemical | medical agents with respect to a treatment site can be provided.

It is principal part sectional drawing of the balloon catheter in this Embodiment. It is a figure which shows the manufacturing method of the balloon catheter in this Embodiment. It is a figure which shows the modification of the film | membrane formed in the outer peripheral surface of the balloon in this Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Balloon catheter 100]
The balloon catheter 100 shown in FIG. 1 is used to deliver a drug for preventing restenosis to a treatment site after expanding a stenosis site (hereinafter referred to as “treatment site”) generated in a blood vessel or the like. The The balloon catheter 100 is provided on a catheter main body 110 to be inserted into a blood vessel and an outer peripheral surface of a distal portion of the catheter main body 110, and a pressurized fluid (for example, a contrast medium or a contrast medium diluted with physiological saline). Is injected, and the balloon 120 expands in the centrifugal direction of the catheter main body 110 (the direction of arrow A in FIG. 1).

  On the outer peripheral surface of the balloon 120, a porous resin film 130 mixed with a drug is formed in advance. A guide wire 150 is inserted through the catheter body 110 and guides the balloon catheter 100 to the treatment site. A method for forming the porous resin film 130 on the outer peripheral surface of the balloon 120 will be described later.

  Inside the catheter main body 110, a guide wire lumen through which the guide wire 150 is inserted and an inflation lumen for injecting a pressurized fluid into the balloon 120 are in the axial direction of the catheter main body 110 (the direction of arrow B in FIG. 1). It is provided along.

  The balloon 120 is provided so as to be in close contact with the outer peripheral surface of the catheter main body 110 with a size approximate to the outer diameter of the catheter main body 110 before the pressurized fluid is injected. When pressurized fluid is injected, the wall of the balloon 120 expands and expands. FIG. 1 shows a state where the balloon 120 is inflated.

[Method for Manufacturing Balloon Catheter 100]
Next, an example of a method for manufacturing the balloon catheter 100 will be described.

<Formation process of balloon 120>
In order to simplify the description, a detailed description of the step of forming the balloon 120 on the outer peripheral surface of the distal portion of the catheter body 110 is omitted, and a method for forming the porous resin film 130 on the outer peripheral surface of the balloon 120 is described below. Will be described.

<Process for producing mixed liquid 190>
First, as shown in FIG. 2A, a medicine 160, for example, a resin 170 such as plastic, and a solvent 180 are mixed at a predetermined ratio to produce a mixed liquid 190.

<Film formation process>
Next, as shown in FIG. 2 (b), the mixed solution 190 is applied substantially uniformly to the outer peripheral surface of the balloon 120 formed at the distal portion of the catheter body 110 to generate a film of the mixed solution 190. Finally, after rapidly freezing the film of the mixed liquid 190 formed on the outer peripheral surface of the balloon 120, the solvent 180 is removed from the film of the mixed liquid 190 by a freeze vacuum drying method.

  As described above, the freeze-drying method 160 is used to freeze the easily-denatured drug 160 and evaporate the solvent 180 in a vacuum, whereby the change of the drug 160 that is vulnerable to heat can be suppressed as much as possible.

  As shown in FIG. 2C, when the solvent 180 is removed by a freeze vacuum drying method, the film of the mixed liquid 190 formed on the outer peripheral surface of the balloon 120 is changed to a porous resin film 130. The thickness of the porous resin film 130 is, for example, 3/100 [mm]. The porous resin film 130 has a plurality of holes 130a and a drug-carrying resin portion 130b in which the drug 160 is mixed in a region other than the holes 130a. FIG. 2 (d) is a view showing the appearance of the porous resin film 130 formed on the outer peripheral surface of the balloon 120.

[Procedure for using balloon catheter 100]
Next, a procedure for delivering a drug 160 for preventing restenosis to the treatment site using the balloon catheter 100 after expanding a stenosis site (treatment site) generated in a blood vessel or the like will be described.

  First, the surgeon inserts the balloon catheter 100 in a state where the balloon 120 is not inflated along the guide wire 150 inserted into the blood vessel through the treatment site to the treatment site.

  Next, the balloon 120 is expanded in diameter by injecting a liquid such as physiological saline with a syringe (not shown) connected to the proximal portion of the catheter body 110. Thereby, the hole 130a of the porous resin film 130 formed on the outer peripheral surface of the balloon 120 is cracked, and blood in the blood vessel enters the hole 130a from the cracked portion. The blood that has entered the hole 130a and the drug 160 in the drug-carrying resin portion 130b are mixed in the hole 130a. Then, when the mixed blood flows out to the treatment site, the medicine 160 is released to the treatment site.

  Thereafter, the operator draws the balloon catheter 100 by contracting the balloon 120 by sucking a liquid such as physiological saline with a syringe. Finally, by pulling out the guide wire 150, the operation of delivering the medicine 160 to the treatment site is completed.

  As described above in detail, the balloon catheter 100 of the present embodiment is provided on the catheter body 110 and the distal portion of the catheter body 110, and by injecting fluid through the lumen in the catheter body 110, the balloon body 100 of the catheter body 110 is provided. It has a balloon 120 that expands in the centrifugal direction, and a porous resin film 130 formed on the outer peripheral surface of the balloon 120. In the porous resin film 130, the medicine 160 is mixed in the medicine carrying resin portion 130b other than the holes 130a.

  According to the present embodiment configured as described above, when the balloon catheter 100 is moved to the treatment site, the resin 170 of the porous resin film 130 serves as a wall that prevents the drug 160 from melting. Therefore, it is possible to prevent the amount of the medicine 160 that can be delivered to the treatment site from decreasing before the balloon catheter 100 reaches the treatment site.

  In addition, since the balloon 120 and the porous resin film 130 are separately provided in the balloon catheter 100, even if the diameter of the balloon 120 is greatly expanded so that all the holes 130a of the porous resin film 130 are cracked. The balloon 120 itself is not thinned, and there is no fear of the balloon 120 being broken. Therefore, it is possible to prevent the drug 160 from remaining in the porous resin film 130 when the balloon 120 is expanded, and to deliver a necessary amount of the drug 160 to the treatment site.

  Further, according to the method for producing the porous resin film 130 in the present embodiment, when the mixed liquid 190 is produced, the amount of the medicine 160 delivered to the treatment site can be easily controlled by changing the concentration of the medicine 160. Can do. Further, by changing the amount of the solvent 180, the release speed of the drug 160 to the treatment site can be easily controlled. For example, if the amount of the solvent 180 is increased, the pores 130a of the porous resin film 130 are increased, and the porous resin film 130 is easily cracked when the diameter of the balloon 120 is increased. Therefore, the release speed of the drug 160 to the treatment site can be increased. On the other hand, if the amount of the solvent 180 is decreased, the pores 130a of the porous resin film 130 are reduced, and the porous resin film 130 is less likely to be cracked when the diameter of the balloon 120 is expanded. Therefore, the release speed of the drug 160 to the treatment site can be slowed.

  In the above embodiment, as shown in FIG. 3, a protective film 200 may be formed on the outer peripheral surface of the porous resin film 130. In this way, when the balloon catheter 100 is moved to the treatment site, the medicine 160 can be more reliably prevented from melting. The protective film 200 may be made of, for example, a material having a low expansion rate or a porous resin material from the viewpoint of facilitating tearing when the balloon 120 is expanded and from the viewpoint of increasing the release speed of the drug 160 to the treatment site. When the protective film 200 is made of a porous resin material, the protective film 200 includes a protective film 200 from the viewpoint of preventing the drug 160 from being unnecessarily melted from the protective film 200 when the balloon catheter 100 is moved to the treatment site. It is desirable that the medicine 160 is not mixed.

  Moreover, although the said embodiment demonstrated the example which the chemical | medical agent 160 mixed in the porous resin film 130 is a chemical | medical agent which prevents restenosis, this invention is not limited to this. Drug 160 is, for example, an antispasmodic, antithrombotic, antiplatelet, antibiotic, steroid, antioxidant, anticancer, anti-inflammatory, chemotherapeutic, anticoagulant, or a combination thereof. Also good.

  Moreover, although the balloon catheter 100 demonstrated the example used in order to deliver the chemical | medical agent 160 with respect to the treatment site | part in the blood vessel in the said embodiment, this invention is not limited to this. For example, the present invention can be applied to a treatment site in a lumen other than a blood vessel (for example, stomach).

  In addition, each of the above-described embodiments is merely an example of actualization 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.

DESCRIPTION OF SYMBOLS 100 Balloon catheter 110 Catheter main body 120 Balloon 130 Porous resin film 130a Hole 130b Drug carrying resin part 150 Guide wire 160 Drug 170 Resin 180 Solvent 190 Mixed liquid 200 Protective film

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 a fluid through a lumen in the catheter body;
A porous resin film formed on the outer peripheral surface of the balloon and cracked when the balloon expands in diameter ;
Have
The hole of the porous resin film is a starting point of the crack of the porous resin film when the balloon is expanded, and is a region other than the hole of the porous resin film that is a cracked portion when the balloon is expanded. The balloon catheter that contains the drug.   The balloon catheter according to claim 1, wherein a protective film is formed on an outer peripheral surface of the porous resin film.   The balloon catheter according to claim 2, wherein the protective film is made of a porous resin material. A first step of forming a film of a mixed solution in which a drug, a resin and a solvent are mixed on an outer peripheral surface of a balloon formed in a distal portion of the catheter body;
The solvent is removed from the film of the mixed liquid formed on the outer peripheral surface of the balloon by a vacuum freeze-drying method , the film of the mixed liquid has a hole that becomes a starting point of a crack when the balloon is expanded, and A second step of changing the region other than the holes into a porous resin film that becomes a cracked portion when the balloon is expanded ,
A method for manufacturing a balloon catheter.

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