JPH10277157A - Balloon expansion catheter and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balloon expansion catheter having both a set strength and compliance by forming by vapor deposition a film of coating material whose tensile strength and/or tensile elastic coefficient is larger than that of a basic material constituting a balloon, on a surface of the basic material. SOLUTION: A film of coating material 12 is formed on an outer or inner surface of a basic material constituting a balloon by vapor deposition. The coating may be applied to a part of a catheter to which the balloon is mounted as well as to the balloon. As the coating material 12, one such as p-kylylene polymer may be used which can form a film by vapor deposition and which is larger in its tensile strength and/or tensile elastic coefficient than that of the basic material 11. With such a constitution, the balloon is reinforced with the film, thereby keeping the compliance as well as design strength and improving operability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a balloon dilatation catheter and a method for manufacturing the same. More particularly, the present invention relates to a balloon dilatation catheter having a balloon having both designed strength and compliance, and a manufacturing method capable of easily manufacturing the balloon dilatation catheter.

[0002]

2. Description of the Related Art Percutaneous transluminal coronary artery dilatation (PTCA)
In order to treat a stenosis in a blood vessel, a balloon dilatation catheter is inserted into the blood vessel, and the stenosis is expanded by inflating the balloon to improve blood flow on the distal side of the stenosis. Percutaneous transluminal coronary artery dilatation with a balloon dilatation catheter has been frequently used instead of conventional surgery for diseases caused by stenosis of the stenosis. The mechanism of vasodilation by balloons is complicated,
It was initially thought that the atheroma itself was compressed by the pressure of the balloon, thereby expanding the vascular lumen. However, as pathological studies progress, the release of atheroma into the vascular lumen, tearing of the intima, and dissection of the media, etc., are involved in the vasodilator mechanism, not just by plaque compression I knew it. In addition, as doctors' skills have improved, there has been an increasing demand for treating lesions faster, easier and more accurately. For this reason, various characteristics are also required for the balloon dilatation catheter, and a product that has not been conventionally conceived and has been accurately designed to achieve both strength and compliance has been required. FIG. 1 is an explanatory diagram of percutaneous transluminal coronary artery dilatation. First, after inserting the guiding catheter up to the entrance of the coronary artery, as shown in FIG. 1A, the guide wire 3 is inserted beyond the stenotic portion 2 of the coronary artery 1, and the balloon dilatation catheter 4 is inserted through the guide wire.
Next, as shown in FIG. 1 (b), the balloon 5 is carried to the stenosis, and is inflated with a low pressure of 30 to 40 psi to confirm that the depression is in the center. Once the pressure of the balloon is released to the state shown in FIG. 1 (c), the state shown in FIG.
As shown in (e), the balloon 5 is inflated at a high pressure of 80 to 120 psi to dilate the stenosis of the blood vessel. Finally, as shown in FIG. 1 (f), the balloon dilatation catheter 4 is retracted, and depending on the condition of the stenosis, the size of the balloon is further increased and the same treatment is repeated. The stenosis of a diseased blood vessel is generally brittle and often hardened by calcification. Therefore, in expanding the stenosis, taking into account the strength and compliance of the blood vessels,
There is a need to expand in steps, such as from 2.00 mm to 2.25 mm. For this reason, when a certain pressure is applied to the catheter, the outer diameter of the balloon is increased as designed, that is, it is required that the balloon has a designed compliance. Generally, a balloon made of ordinary polyethylene or the like has too high compliance, and when the pressure is increased for dilatation of the blood vessel, the balloon is often broken, or the balloon is large and conversely damages the blood vessel. Further, when the compliance is small like polyester, the pressure resistance is easily increased, but the balloon is hardened and the catheter is difficult to enter a curved blood vessel (so-called trackability is reduced). Furthermore, when dilating a blood vessel, many different sized catheters are required. Therefore, it is desired to have an appropriate compliance, pressure resistance, softness, and easy insertion into a blood vessel. For this reason, if a strong polymer is processed to be thin, the rigidity of the catheter is appropriate,
Also, the pressure resistance falls within an appropriate range, but processing is extremely difficult, and the crunchiness inherent to the material still remains. As a result of various investigations as a method of eliminating the crunchiness, it has been known from many years ago that the application of a multilayer with a soft polymer is effective in many applications of polymers. Therefore, it is extremely effective if a very strong polymer can be treated in a multilayered manner. However, even if thermoforming is considered, it is not easy to process due to differences in the melting point and polarity of the raw material polymer. Further, even when dipping or the like using a solvent is used, the physical properties and shape of the base balloon are impaired due to the influence of the solvent. Increasing the film thickness with a soft polymer increases the balloon profile (projected area), again impairing blood vessel permeability. If the balloon ruptures without being able to withstand the pressure when dilating a stenosis of a blood vessel, it may not only hinder the operation but also may injure the patient. For this reason, the balloon is designed to have a sufficient strength. However, if a polymer having an extremely high cohesive force is used, the forming process is hindered, and it is difficult to produce a uniform balloon.
On the other hand, polymers with good processability generally have low strength,
When the thickness of the balloon is increased to increase the strength, the projected cross-sectional area of the balloon, that is, the so-called profile, increases, and the stenosis passageability of the balloon dilatation catheter decreases. Further, if the strength is increased by increasing the stretching ratio during the balloon stretching process, the balloon membrane tends to be easily torn. Various attempts have been made to solve these problems. For example, Japanese Patent No. 2516096 discloses that a balloon can be made thinner while sufficiently securing the flexibility, strength and durability of the balloon, and as a balloon having excellent blood compatibility, a crystalline plastic is used. There has been proposed a balloon made of a thin-walled material composed of a laminate having an inner layer formed integrally with the inner layer and an outer layer formed of an elastic material having blood compatibility. However, such a laminate is formed by two-color molding, insert molding,
The process of manufacturing by a two-layer tube molding or the like is complicated, and the method of applying, spraying or dipping the solution of the exterior material on the preformed inner layer has an adverse effect on the subject due to the remaining trace amount of solvent. Is concerned.
Conventionally, a balloon is formed by stretching or dipping from a film made of a single polymer material, a multilayer film of a polymer material, or a film made of a blend of multiple polymer materials to obtain the required strength. For this purpose, processing conditions, balloon thickness, and the like have been adjusted, but it has been difficult to achieve both designed strength and compliance by such means. Also, after processing the balloon using a commonly used polymer material with good workability, polymer materials with different tensile strength and tensile modulus are coated by solution coating, dipping, etc., and designed for strength and compliance. An attempt was also made to obtain a balloon having the following properties, but there was a problem that the uniformity and strength of the balloon were lost due to the influence of a solvent or heat. Therefore, there is a need for a balloon for a balloon dilatation catheter having a designed strength and compliance desired, and a manufacturing method capable of easily manufacturing the balloon dilatation catheter.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a balloon dilatation catheter having a balloon having a designed strength and compliance, and a manufacturing method capable of easily producing the balloon dilatation catheter. It was made for the purpose.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, the surface of the base material constituting the balloon has a higher tensile strength and / or tensile elasticity than the base material. It is possible to adjust the strength and compliance of the balloon by forming a film made of a coating material with a high rate, and to arbitrarily adjust the thickness of the film by forming a film made of the coating material by vapor deposition polymerization. It has been found that a balloon having controlled and designed strength and compliance can be easily obtained, and based on this finding, the present invention has been completed. That is, the present invention provides (1) a balloon dilatation catheter for use with a guidewire, wherein a lumen for fluid supply for inflating a balloon that penetrates the inside of the catheter shaft and opens inside the balloon, and a guidewire insertion hole A flexible catheter shaft having a lumen, and a balloon mounted near the distal end of the catheter, wherein the outer and / or inner surface of the base material comprising the balloon has a higher tensile strength and / or strength than the base material. A balloon dilatation catheter characterized in that a film made of a coating material having a high tensile modulus is formed by a vapor deposition polymerization method, and (2) a tensile strength and / or a tensile modulus higher than a base material of the balloon. A monomer for forming a coating material is generated by heating, and the monomer is transferred to a deposition chamber. In the vapor deposition chamber, the monomer is condensed on the outer surface and / or inner surface of the base material of the tubular balloon, and polymerized in the condensed phase to form a balloon having a multilayer structure composed of the base material and the coating material. Is located near the distal end of a flexible catheter shaft having a lumen for fluid delivery for inflating a balloon opened near the distal end, and a guide wire insertion lumen, which penetrates the inside of the catheter shaft. A method of manufacturing a balloon dilatation catheter, wherein the balloon dilatation catheter is attached to an inflation portion of the balloon such that the opening of the fluid-feeding lumen is located at
Is provided. Further, as a preferred embodiment of the present invention, (3) the balloon dilatation catheter according to (1), wherein the coating material is a p-xylylene polymer.
And (4) the method for producing a balloon dilatation catheter according to (2), wherein the coating material is a p-xylylene polymer. The compliance in the present invention herein, the outer diameter of the balloon when the outer diameter of the balloon when subjected to normal pressure and d _0, rupture verge of the balloon (at least 90% is not ruptured) multiplied by the internal pressure until Is d ₁ and the value of (d ₁ −d ₀ ) / d ₀ is referred to.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The balloon dilatation catheter of the present invention is a balloon dilatation catheter to be used with a guide wire, and is for passing a fluid for inflating a balloon which has penetrated the inside of a catheter shaft and opened inside the balloon. And a flexible catheter shaft having a lumen for passing a guidewire therethrough, and a balloon attached near the distal end of the catheter, the outer surface of a base material constituting the balloon and / or On the inner surface, a film made of a coating material having higher tensile strength and / or tensile elastic modulus than the base material is formed by a vapor deposition polymerization method. FIG. 2 is a side view near the distal end of one embodiment of the balloon dilatation catheter of the present invention.
(a), a sectional view (b), a sectional view (c), and a side view (d) of a state where the balloon is inflated. The balloon dilatation catheter according to the present embodiment is used for fluid delivery for inflating a balloon 5 attached near the distal end 6 of the catheter and a balloon having an opening 8 inside the catheter shaft 7 through the inside of the catheter shaft 7. It consists of a flexible catheter shaft having a lumen 9 and a guide wire insertion lumen 10. The balloon dilatation catheter carries the balloon to the stenotic part of the blood vessel, sends a fluid for inflating the balloon from the fluid supply lumen, and inflates the balloon as shown in FIG. To expand.

FIG. 3 is a sectional view of three types of balloons used in the balloon dilatation catheter of the present invention. FIG.
In the balloon shown in (a), a film made of a coating material 12 is formed on the outer surface of a base material 11 constituting the balloon. The balloon shown in FIG. 3B has a coating made of a coating material 12 formed on an inner surface of a base material 11 constituting the balloon. In the balloon shown in FIG. 3C, a coating made of a coating material 12 is formed on an outer surface and an inner surface of a base material 11 constituting the balloon. In addition, after the balloon is attached, not only the balloon but also a part of the catheter may be coated. In the present invention, the coating material that forms a film on the surface of the balloon base material has a higher tensile strength and / or tensile modulus than the base material, and the film is formed by vapor deposition polymerization. There is no particular limitation on the shape of the balloon used in the balloon dilatation catheter of the present invention. For example, as shown in FIG. 3, a tubular shape in which the diameter of the central inflatable portion 14 is larger than the diameter of the adhesive portions 13 at both ends can be used. Alternatively, it is possible to form a tube in which the diameter of the adhesive portion and the diameter of the expanding portion are the same. In the present invention, the base material forming the balloon is not particularly limited, and a polymer material that can be formed into a tube shape can be used. Examples of such a polymer material include polyolefin,
Examples include polyester, polyamide, polyimide, polyurethane, polyvinyl halide, polyvinylidene halide, fluorine resins such as PFA, FEP, and PTFE, and ethylene-vinyl acetate copolymer.
These polymeric materials can be used alone, can be used as a blend, or can be used as a multilayer. Among these polymer materials, linear low density polyethylene (LLDPE), polyethylene terephthalate (PET), nylon 11, and polyester elastomer can be particularly preferably used.

In the present invention, there is no particular limitation on the coating material having a higher tensile strength and / or tensile modulus than the base material, and any material capable of forming a film by vapor deposition polymerization can be used. Such materials include:
For example, a p-xylylene polymer can be mentioned. The p-xylylene polymer has the formula [1], the formula [2],
P- represented by Formula [3], Formula [4], Formula [5], etc.
It can be obtained from xylylene dimer.

Embedded image The p-xylylene polymer obtained from the p-xylylene dimer represented by the formula [1] has a tensile strength of 45 MPa and a tensile modulus of elasticity of 2.4 GPa.
The p-xylylene polymer obtained from the xylylene dimer has a tensile strength of 70 MPa and a tensile modulus of 3.2 GPa, and the p-xylylene polymer obtained from the p-xylylene dimer represented by the formula [3] has a tensile strength of 75 MPa. ,
Since it has a tensile modulus of 2.8 GPa, based on the tensile strength and tensile modulus of the base material constituting the balloon,
A coating material having a higher tensile strength and / or tensile modulus than the base material can be selected. According to the vapor deposition polymerization method, it is possible to uniformly form a film having an arbitrary thickness made of a coating material. Therefore, in the present invention, by appropriately selecting the coating material and the vapor deposition polymerization conditions, the design can be made. A balloon having improved strength and compliance can be obtained. A coating made of a coating material formed by a vapor deposition polymerization method on a surface of a base material constituting a balloon does not have a risk of peeling off and falling off unlike a coating formed by coating, dipping, or the like. In the balloon dilatation catheter of the present invention, the size of the balloon is not particularly limited, but usually the outer diameter of the balloon is 1.2 to 6.0 mm, and the length of the balloon is preferably 10 to 100 mm. . In the balloon dilatation catheter of the present invention, the catheter shaft is not particularly limited, but usually fits a guide wire having an outer diameter of 0.008 to 0.018 inches and an effective length of 100 to 150.
A cm catheter shaft can be suitably used. The material of the catheter shaft is not particularly limited, and nylon, polyethylene, polyimide, polyurethane, polyvinyl chloride, a blend thereof, and materials conventionally used for balloon dilatation catheters can be used without any particular limitation.

FIG. 4 is an explanatory view of one embodiment of the method for manufacturing the balloon dilatation catheter of the present invention. In the embodiment shown in FIG. 4A, an apparatus including a vaporizer 15, a pyrolysis furnace 16, a deposition chamber 17, a cooling trap 18, and a vacuum pump 19 is used as a manufacturing apparatus. In the method of the present invention, first, a portion made of a base material of a balloon is formed. Although there is no particular limitation on the method of forming the portion serving as the base material of the balloon, usually, a polymer material serving as the base material is formed into a tube having a desired diameter, cut into a desired length, and cut into a desired length. Accordingly, the bonding portion and the inflated portion having different diameters can be shaped by using a balloon machine. The portion made of the balloon base material is preferably biaxially stretched, and the stretching ratio is not particularly limited,
Usually, it is preferable to stretch 2 to 4 times in the diameter direction and 1 to 3 times in the axial direction. The base material of the formed balloon is put into a deposition chamber of the apparatus shown in FIG. In order to obtain the balloon shown in FIG. 3A in which a film made of a coating material is formed on the outer surface of the base material, the openings at both ends of the balloon are closed with a stopper or the like, and the balloon is put into a deposition chamber. After forming a film on the outer surface of the balloon, the plug is removed. In order to obtain the balloon shown in FIG. 3B in which a coating made of the coating material is formed on the inner surface of the base material, the outer surface of the balloon is masked and put into a deposition chamber, and the coating made of the coating material is placed on the balloon. After forming on the inner surface of the, the masking is removed. In order to obtain the balloon shown in FIG. 3 (c) in which the coating made of the coating material is formed on the outer and inner surfaces of the base material, the formed balloon is put into a deposition chamber as it is, and the coating made of the coating material is placed on the balloon. Formed on the outer surface and inner surface. The base material of the balloon is placed in a deposition chamber, and the raw material of the coating material is charged into a vaporizer. When a p-xylylene polymer is used as the coating material, the raw material is a p-xylylene dimer represented by Formulas [1] to [5]. The p-xylylene dimer is evaporated by heating in a vaporizer. The heating temperature in the vaporizer is 170 to 20
Preferably it is 0 ° C. The raw material vapor generated in the vaporizer is led to a pyrolysis furnace and heated in the pyrolysis furnace to become a monomer. The heating temperature in the pyrolysis furnace is 60
The temperature is preferably from 0 to 700 ° C. The monomer generated in the pyrolysis furnace is guided to a deposition chamber kept at a normal temperature, and is condensed and coated on the outer surface and / or the inner surface of a balloon made of a tubular base material in the deposition chamber. The monomer obtained from the p-xylylene dimer is a p-xylylene biradical, and the condensed monomer becomes a polymer by radical polymerization in the condensed phase, and reacts radically with the base material to be strongly bonded by a covalent bond. . FIGS. 4B and 4C are partially cutaway views of another embodiment of the deposition chamber. In the embodiment shown in FIG. 4B, a rotation chamber 21 rotated by a motor 20 is provided in the evaporation chamber 17,
The base material 22 of the balloon contained in the rotating chamber is uniformly coated because it moves randomly in the rotating chamber as the rotating chamber rotates. In the embodiment shown in FIG.
7 has a rotating plate 23 rotated by a motor 20 and a base material 2 of a balloon placed on the rotating plate.
2 is uniformly coated because it makes a circular motion in the deposition chamber with the rotation of the rotating plate.

Under predetermined conditions, vapor deposition polymerization is performed for a predetermined period of time, and a balloon having a coating of a desired thickness formed on the outer surface and / or inner surface of the base material is passed through the inside of the catheter shaft, and the distal end is formed. Fluid delivery to the inflatable portion of the balloon near the distal end of a flexible catheter shaft having a lumen for inflating a balloon having an opening near the end and a guidewire insertion lumen. The balloon dilatation catheter of the present invention can be obtained by mounting so that the opening of the lumen for use is located. The balloon dilatation catheter manufactured by the method of the present invention includes:
Since the balloon is reinforced by a coating made of a coating material having a higher tensile strength and / or tensile modulus than the base material and has a designed strength and compliance,
Operability is good. According to the method of the present invention, after molding using a base material having good workability, a film made of a coating material is formed to a required thickness by a vapor deposition polymerization method. The application step can be separated as a separate step, and a balloon dilatation catheter excellent in strength can be easily obtained. In the method of the present invention, the processed base material of the balloon is kept at room temperature and forms a film made of the coating material on its surface, so that it is not affected by the temperature or the solvent that impairs the shape or physical properties. . After treating a stenotic portion of a coronary artery by percutaneous transluminal coronary artery dilatation, an intracoronary stent implantation is performed to place a stent in the coronary artery to prevent restenosis. Intracoronary stents include
There are self-expanding stents that have elasticity that the stent itself tends to expand, and balloon-expandable stents that are expanded by a balloon. Both of them need to be transported into a coronary artery by a stent delivery catheter. On the outer surface of the base material constituting the balloon as the stent holding portion of the stent delivery catheter, a film made of a coating material having a surface tack that is more flexible than the base material is formed by a vapor deposition polymerization method, so that the catheter during the transfer of the stent is transferred. Of the stent can be prevented.

[0010]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. In the examples and comparative examples, the evaluation of pressure resistance and compliance was performed by the following methods. (1) Pressure resistance With respect to 10 balloons, the pressure at the time of bursting by applying internal pressure is measured, and the average value of 10 balloons is determined. (2) Compliance The diameter of the balloon when the internal pressure of the degree normally used (for example, about 6 kg / cm ² ) is not applied is d ₀ , and the diameter of the balloon when the internal pressure is about to burst is d _1, and compliance = ( From d ₁ −d ₀ ) / d ₀ , the average value for 10 balloons is determined. If the balloon ruptures, the test is continued until 10 readings are obtained. Example 1 Using a linear low-density polyethylene, a base material having a thickness of 40 μm, a draw ratio of 3 times in the diameter direction, a draw ratio of 1.2 times in the axial direction, a diameter of 2.00 mm, and a length of 25.0 mm was produced. . On the outer surface of this base material, the formula [2]

Embedded image Vapor deposition polymerization was performed for 2 hours using Parylene C represented by
A film having a thickness of 10 μm was formed. The pressure resistance of this balloon was 12 kg / cm ² , and the compliance was 0.15. Example 2 Using a linear low-density polyethylene, a base material having a thickness of 30 μm, a draw ratio of 3 in the diameter direction, a draw ratio of 1.2 in the axial direction, a diameter of 2.00 mm, and a length of 25.0 mm was produced. . On the outer surface of the base material, vapor deposition polymerization was carried out using Parylene C for 4 hours to form a film having a thickness of 20 μm. The pressure resistance of this balloon was 17 kg / cm ² , and the compliance was 0.06. Example 3 Using polyethylene terephthalate, a thickness of 10 μm,
3 times the stretching ratio in the diameter direction, 1.2 times the stretching ratio in the axial direction,
A base material having a diameter of 2.00 mm and a length of 25.0 mm was prepared. On the outer surface of this base material, vapor deposition polymerization was carried out using Parylene C for 2 hours to form a film having a thickness of 10 μm. The pressure resistance of this balloon was 20 kg / cm ² , and the compliance was 0.06. Example 4 Using nylon 11, a thickness of 20 μm, a stretching ratio of 3 in the diameter direction, a stretching ratio of 1.2 in the axial direction, a 2.00 mm diameter,
A base material having a length of 25.0 mm was prepared. On the outer surface of this base material, vapor deposition polymerization was carried out using Parylene C for 2 hours to form a film having a thickness of 10 μm. The balloon has a pressure resistance of 20 kg / cm ² and a compliance of 0.06.
Met. Example 5 Polyester elastomer [Du Pont, Hyt
rel], a base material having a thickness of 20 μm, a draw ratio of 3 in the diameter direction, a draw ratio of 1.2 in the axial direction, a diameter of 2.00 mm, and a length of 25.0 mm was prepared. On the outer surface of this base material, vapor deposition polymerization was carried out using Parylene C for 2 hours to form a film having a thickness of 10 μm. The pressure resistance of this balloon was 16 kg / cm ² , and the compliance was 0.05. Example 6 Using a linear low-density polyethylene, a base material having a thickness of 10 μm, a stretching ratio of 3 in the diameter direction, a stretching ratio of 1.2 in the axial direction, a diameter of 2.00 mm, and a length of 25.0 mm was produced. . On the outer surface of the base material, vapor deposition polymerization was carried out using Parylene C for 4 hours to form a film having a thickness of 20 μm. The pressure resistance of this balloon was 14 kg / cm ² , and the compliance was 0.06. Comparative Example 1 Using a linear low-density polyethylene, a balloon having a thickness of 50 μm, a stretching ratio of 3 in the diameter direction, a stretching ratio of 1.2 in the axial direction, a diameter of 2.00 mm, and a length of 25.0 mm was produced. The pressure resistance of this balloon was 8 kg / cm ² , and the compliance was 0.25. Comparative Example 2 A balloon having a thickness of 30 μm, a stretching ratio of 3 in the diameter direction, a stretching ratio of 1.2 in the axial direction, a diameter of 2.00 mm, and a length of 25.0 mm was produced using polyethylene terephthalate. The pressure resistance of this balloon was 16 kg / cm ² , and the compliance was 0.02. Comparative Example 3 Using nylon 11, a thickness of 30 μm, a draw ratio of 3 in the diameter direction, a draw ratio of 1.2 in the axial direction, 2.00 mm in diameter,
A 25.0 mm long balloon was made. The balloon has a pressure resistance of 16 kg / cm ² and a compliance of 0.0.
It was 7. Comparative Example 4 Polyester Elastomer [Du Pont, Hyt
rel], a balloon having a thickness of 30 μm, a draw ratio of 3 in the diameter direction, a draw ratio of 1.2 in the axial direction, a diameter of 2.00 mm, and a length of 25.0 mm was produced. The pressure resistance of this balloon was 12 kg / cm ² , and the compliance was 0.20. The results of Examples 1 to 6 and Comparative Examples 1 to 4
It is shown in the table.

[0011]

[Table 1]

The balloons of Example 1, Example 2 and Comparative Example 1 all have a total thickness of 50 μm, but the balloon of Comparative Example 1 formed only of linear low-density polyethylene is
Compliance is too large, and pressure resistance is low,
There is a risk of damaging the vessel wall during use and a risk of rupture. On the other hand, the outer surface of the base material made of linear low-density polyethylene is
The balloon of Example 1 in which the μm film was formed had high pressure resistance and compliance was large enough not to damage the blood vessel wall. Further, the balloon of Example 2 in which a film having a thickness of 20 μm was formed with Parylene C has a further increased pressure resistance and a compliance of 0.0 which does not hinder use.
The value of 6 is maintained. The balloon of Example 3, in which a coating made of parylene C was formed on the outer surface of a base material made of polyethylene terephthalate, realized a low profile with a small total thickness of 20 μm, improved pressure resistance and compliance, and was easy to use. It has become something. On the other hand, the balloon of Comparative Example 2 formed of only polyethylene terephthalate has too low compliance, and is difficult to use, and has a lower pressure resistance than the balloon of Example 3. The balloons of Example 4 and Comparative Example 3 each had a total wall thickness of 30 μm, whereas the balloon of Comparative Example 3 formed of only nylon 11 had a pressure resistance of 16 kg / cm ² . In the balloon of Example 4 in which a film made of parylene C was formed on the outer surface of the base material made of nylon 11, the compliance value was hardly changed, and the pressure resistance was improved to 20 kg / cm ² . The balloons of Example 5 and Comparative Example 4 each had a total wall thickness of 30 μm, but the balloon of Comparative Example 4 formed of only a polyester elastomer had too high compliance and a pressure resistance of 12 kg / cm ² . On the other hand, the balloon of Example 5 in which a coating made of parylene C was formed on the outer surface of a base material made of a polyester elastomer,
Compliance is maintained at a value of 0.05 which does not hinder use, and pressure resistance is improved to 16 kg / cm ² . The balloon having a coating made of parylene C formed on the outer surface of the base material made of the linear low-density polyethylene of Example 6 has a compliance of 0.06 at which there is no problem in use, and the pressure resistance is large when the wall thickness is 30 μm. 14kg / cm
^It has a value of ² .

[0013]

According to the method of the present invention, the balloon of the balloon dilatation catheter of the present invention has both the designed strength and compliance as desired and can have a low profile while maintaining sufficient strength and compliance. In this case, the balloon dilatation catheter can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of percutaneous transluminal coronary artery dilatation.

FIG. 2 is a side view and a cross-sectional view of the vicinity of a distal end of one embodiment of the balloon dilatation catheter of the present invention.

FIG. 3 is a cross-sectional view of three types of balloons used for the balloon dilatation catheter of the present invention.

FIG. 4 is an explanatory view of one embodiment of a method for manufacturing a balloon dilatation catheter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coronary artery 2 Stenosis part 3 Guide wire 4 Balloon dilatation catheter 5 Balloon 6 Distal end 7 Catheter shaft 8 Opening 9 Fluid feeding lumen 10 Guide wire insertion lumen 11 Base material 12 Coating material 13 Adhesive part 14 Inflation part 15 Vaporizer 16 Pyrolysis furnace 17 Deposition chamber 18 Cooling trap 19 Vacuum pump 20 Motor 21 Rotating chamber 22 Balloon base material 23 Rotating plate

Claims (2)

[Claims] 1. A balloon dilatation catheter for use with a guidewire, comprising: a lumen for feeding a fluid for inflating a balloon that penetrates the inside of the catheter shaft and opens inside the balloon; and a lumen for inserting the guidewire. A flexible catheter shaft and a balloon mounted near the distal end of the catheter, wherein the outer and / or inner surface of the base material comprising the balloon has a higher tensile strength and / or tensile modulus than the base material. A balloon dilatation catheter, wherein a coating made of a large coating material is formed by a vapor deposition polymerization method. 2. A method for producing a monomer which forms a coating material having a higher tensile strength and / or a higher tensile modulus than a base material of a balloon by heating, guides the monomer to a vapor deposition chamber, and converts the monomer into a tubular shape in the vapor deposition chamber. Is condensed on the outer surface and / or inner surface of the base material of the balloon, and polymerized in the condensed phase to form a multi-layered balloon composed of the base material and the coating material. Near the distal end of a flexible catheter shaft having a lumen for inflating a balloon that is opened near the end and a lumen for inserting a guide wire, a fluid inflation portion of the balloon is provided near the distal end of the flexible catheter shaft. The balloon dilatation catheter, which is attached so that the opening of the cavity is located. Production method.