JPH06296693A - Production of catheter for expanding blood vessel - Google Patents

Abstract

PURPOSE:To provide the process for production of the catheter for expanding blood vessels which is improved in the pressure withstanding property of a balloon at the time of a PTCA operation. CONSTITUTION:Adhesive part 15, 15 on the surface of a polyethylene shaft 3 are previously subjected to irradiation with plasma by a inert gas. The polyethylene naphthalate balloon 4 is adhered with an adhesive to these adhesive parts 15, 15. The balloon catheter 2 is formed. The adhesiveness of the balloon catheter 2 to the shaft 3 of the balloon 4 is improved. The pressure withstanding property of the balloon 4 at the time of the PTCA operation is improved.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for manufacturing a vasodilator catheter. More specifically, the present invention relates to a method for manufacturing a vasodilation catheter having improved balloon pressure resistance during surgery by improving the adhesion of the balloon catheter to the shaft of the balloon.

[0002]

2. Description of the Related Art In recent years, percutaneous coronary angioplasty (hereinafter referred to as "PTCA", which has become a mainstream along with coronary artery bypass surgery as a treatment method for angina).
nal Coronary Angioplasty) is a method of positioning the balloon of a vasodilator catheter at the stenotic part of the coronary artery (atherosclerotic part) and expanding the stenotic part by inflating the balloon with high pressure.

As shown in FIG. 3, the blood vessel dilatation catheter used in this PTCA is composed of a tubular guide catheter 1 and a balloon catheter 2 which is inserted into the guide catheter 1. Further, as shown in FIG. 1, the balloon catheter 2 is formed of a cylindrical shaft 3 and a substantially cylindrical balloon 4 covering the outer peripheral surface of the shaft 3, and a hole 5 formed in the shaft 3. Through
The inside 6 of the balloon 4 communicates with the inside 7 of the shaft 3. Both ends of the balloon 4 are adhered to the shaft 3 and closed.

At the time of surgery, as shown in FIG. 3, the guide catheter 1 is advanced to the coronary artery entrance through the femoral artery or the like under radioscopy, and then the balloon catheter 2 is inserted into the guide catheter 1. Then, the balloon 4 is advanced again until the balloon 4 is positioned at the target narrowed portion 9 of the coronary artery 8 as shown in FIG. 4 (a). In this state, as shown in FIG. 4B, while the contrast agent is being injected into the inside 6 of the balloon 4, the balloon 4 is inflated by pressurizing at 7 to 10 atmospheres to expand the narrowed portion 9. Next, balloon catheter 2
When the above is removed, expansion of the narrowed portion 9 is confirmed as shown in FIG. 4 (c). For injection and pressurization of the contrast agent, an extracorporeal pressurizing device (not shown) connected to the proximal end (not shown) of the balloon catheter 1 is used, and the inside 7 of the shaft 3 and the hole 5 Through.

However, the balloon catheter 2 is required to have flexibility so that it can be bent and pass through an artery and have high mechanical strength. Therefore, the balloon catheter 2 is usually made of a polymer material such as a thermoplastic resin, the shaft 3 of the balloon catheter 2 is usually made of polyethylene (hereinafter referred to as “PE”), and the balloon 4 is usually made of polyethylene terephthalate ( Below "P
ET ”), and is made of PET that has been biaxially stretched for the purpose of particularly improving strength.

The conventional PE shaft 3 and P
The balloon catheter 2 including the ET balloon 4 is strong enough to withstand use during surgery, and the PET balloon 4 can withstand a pressure of 7 to 10 atmospheres.

[0007]

However, the above-mentioned P
In the TCA operation, it is desired to further improve the operation efficiency, that is, the expansion efficiency of the stenosis 9 by the balloon 4 of the blood vessel dilation catheter. To achieve this, it is required to further improve the pressure resistance of the conventional balloon 4, that is, to improve the mechanical strength of the balloon 4 and the adhesiveness of the balloon 4 to the shaft 3.

Therefore, the inventors of the present invention made a balloon 4 of PEN by paying attention to polyethylene naphthalate (hereinafter referred to as "PEN") having a mechanical strength higher than that of PET under the condition of biaxial stretching. PE made of PEN balloon 4
As a result of intensive research aimed at improving the adhesiveness to the shaft 3 made of metal, it was discovered that the adhesiveness of the PEN material to the PE material is remarkably improved by pre-irradiating the surface of the PE with an inert gas plasma. The present invention has been reached.

Regarding the plasma irradiation of a medical polymer material, for example, Japanese Patent Laid-Open Nos. 64-17641, 4-159336 and 4-159 have been used.
Japanese Patent Laid-Open No. 337 and Japanese Patent Laid-Open No. 4-159338 disclose that plasma irradiation is performed only for the purpose of enhancing biocompatibility of the material and that plasma irradiation is performed after application of the adhesive. The present invention is clearly different from the present invention.

[0010]

According to the method for producing a vasodilator catheter of the present invention, a polyethylene shaft is made of polyethylene naphthalate after plasma irradiation with an inert gas is previously applied to the adhesion site on the surface of the shaft. The balloon is bonded with an adhesive to form a balloon catheter.

[0011]

The method for manufacturing the vasodilator catheter of the present invention is
By applying plasma irradiation with an inert gas in advance,
Since the adhesion site on the surface of the polyethylene shaft is modified, the affinity between the adhesion site and the adhesive is improved, and the adhesion between the polyethylene shaft and the polyethylene naphthalate balloon is improved. Therefore, the pressure resistance of the balloon during surgery is improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for producing a vasodilator catheter of the present invention will be described below with reference to the drawings.

The parts having the same structure as the above-mentioned conventional blood vessel dilatation catheter will be described with the same reference numerals.

As shown in FIG. 3, the blood vessel dilatation catheter used in the PTCA is composed of a tubular guide catheter 1 and a balloon catheter 2 inserted into the guide catheter 1.

Further, as shown in FIG. 1, the balloon catheter 2 is formed of a tubular shaft 3 and a substantially tubular balloon 4 arranged on the outer peripheral side of the shaft 3 and having both ends closed. The inside 6 of the balloon 4 is connected to the inside 7 of the shaft 3 through the hole 5 formed in the outer periphery of the shaft 3.
It is designed to communicate with. And this balloon 4
Has a central portion 11 formed in a tubular shape with a diameter larger than that of the shaft 3,
Both ends 12, 12 are bonded to the shaft 3 with an adhesive.
In addition, inclined portions 13 and 13 are formed by tapering from the central portion 11 toward both end portions 12 and 12, respectively.

The shaft 3 is made of polyethylene (hereinafter "P
Although referred to as “E”), it is preferable to use low density PE in order to impart flexibility.

Although the balloon 4 is made of polyethylene naphthalate (hereinafter referred to as "PEN"), it is preferable to use a balloon which is biaxially stretched for the purpose of improving strength.

Further, as the adhesive, a high molecular weight polyester adhesive such as Byron (trade name, manufactured by Toyobo Co., Ltd., main component: polybutylene terephthalate, solvent: mixed solution of toluene and methyl ethyl ketone) is used. However, various types of adhesives can be used as long as the PEN material of the balloon 4 and the PE material of the shaft 3 can be sufficiently bonded.

Next, a method for manufacturing the balloon catheter 2 will be described.

First, as shown in FIG.
A cylindrical PEN balloon preliminary body 14 having substantially the same diameter as that of the central portion 11 and having both ends opened is prepared.

Next, plasma irradiation with an inert gas is applied to the bonding portions 15, 15 on the surface of the PE shaft 3.

The plasma irradiation conditions are such that an inert gas such as argon or neon, preferably argon, is used as the discharge gas, the discharge gas pressure is preferably 0.5 torr or more, the plasma irradiation output is preferably 40 W or more, and the plasma irradiation is performed. The time is preferably 1 minute or longer, particularly preferably 5 minutes or longer. In the predetermined range, the larger the discharge gas pressure, the plasma irradiation output, and the plasma irradiation time, the greater the adhesion between the PE material and the PEN material.

Next, after this plasma irradiation, an adhesive is applied to the adhesion portions 15, 15 of the shaft 3. It is preferable to apply the adhesive as soon as possible after the plasma irradiation in order to prevent the unstable radicals generated after the plasma irradiation.

Then, the shaft 3 is passed through the balloon spare body 14, and the balloon spare body is attached to the bonding portions 15, 15 of the shaft 3.
Both ends 12, 14 of 14 are arranged.

Next, a silicone tube (not shown) of substantially the same shape as the both ends of the balloon 4 shown in FIG. 1 and having a slightly larger diameter is brought into contact with the outer peripheral surfaces of the both ends 12, 12 of the balloon preparatory body 14, respectively. Then, the silicone tube is shrunk by a heat gun, a dryer or the like, and both ends 12, 12 of the balloon preparatory body 14 are thermocompression-bonded to the bonding portions 15, 15 of the shaft 3 to bond them. As a result, the balloon preform 14 is transformed into the balloon 4 shown in FIG. 1, the both ends 12, 12 of the balloon 4 are adhered to the shaft 3, and the balloon catheter 2 is obtained.

The temperature of the thermocompression bonding is preferably about 135 ° C to about 145 ° C. This is because the shrinkage of the silicon tube becomes insufficient at 130 ° C or lower, while the PE shaft 3 deforms at 150 ° C or lower.

Next, the operation of the vasodilator catheter of the present invention will be described.

By subjecting at least the bonding portions 15, 15 on the surface of the PE shaft 3 to plasma irradiation with an inert gas in advance, the bonding portions 15, 15 of the PE shaft 3 are modified. The affinity between the adhered parts 15, 15 and the adhesive is improved, and the adhesiveness between the PE material and the PEN material, that is, the adhered parts 15, 15 of the PE shaft 3 and PE.
The adhesiveness between the both ends 12, 12 of the N balloon 4 is improved.

Although the details of the mechanism for modifying the surface of the PE material are not clear, the surface of the PE material is etched and roughened, or radicals are generated to generate oxygen functional groups on the surface of the PE material. It is considered to be modified by introducing a group.

Further, during plasma irradiation, the PE material and the PE material are increased as the discharge gas pressure, the plasma irradiation output, and the plasma irradiation time are increased within a predetermined range.
Since there is a correlation that the adhesiveness with the N material increases, the adhesiveness can be easily controlled by controlling these irradiation conditions. Therefore, by controlling the irradiation conditions, it is possible to easily increase the adhesiveness of only a part of the adhesion site between the PE material and the PEN material, or to partially increase or decrease the adhesiveness.

Since the PEN material used for the balloon 4 has greater mechanical strength than the polyethylene terephthalate (hereinafter referred to as "PET") material conventionally used under the condition of being subjected to biaxial stretching, the balloon 4 itself The mechanical strength of itself can also be improved over the conventional one.

Thus, by using the PEN material, the mechanical strength of the balloon 4 itself can be improved as compared with the conventional one, and the PE shaft 3 of the PEN balloon 4 can be controlled by controlling the plasma irradiation conditions. It is possible to further improve the adhesiveness to. Therefore, the pressure resistance of the balloon 4 during the PTCA operation can be improved, and when the surrounding narrowed portion 9 is expanded in the inflated state as shown in FIG. It is possible to reliably prevent the both ends 12, 4 of the shaft 4 from coming off the shaft 3, and it is possible to safely perform surgery without danger.

In the above embodiment, the description has been made of the case where the tubular PEN balloon preliminary body 14 is used for thermocompression bonding to the shaft 3, but the present invention is not limited to this, and the balloon 4 is omitted. It is also possible to manufacture the same shape in advance and adhere it to the shaft 3, or to make a product in which the shaft 3 has a double pipe structure.

Next, the present invention will be described in more detail with reference to specific examples.

Example 1 The effects of irradiation time and irradiation output on pressure resistance were tested as follows.

First, as shown in FIG. 5 (a), a number of low density polyethylene (PE) tubes 21 (length 5 cm, outer diameter
1.3mm, thickness 0.2mm) was placed in an ampoule 22 and argon gas was filled under the pressure shown in Table 1. Then, as shown in Fig. 5 (b), a high-frequency power supply of 13.56MHz was used to irradiate
The irradiation time was changed as shown in Table 1, and the entire surface of the PE tube 21 was irradiated with plasma.

Next, after the plasma irradiation, the ampoule 22 to P
Take out the tube 21 made of E, and immediately, as shown in FIG. 6 (a), immediately attach the bonding portion 23a of one end of the tubes 21a, 21b made of PE.
, 23b (width 3 mm), 1 mg of high molecular weight polyester adhesive, Byron (trade name, manufactured by Toyobo Co., Ltd., main component: polybutylene terephthalate, solvent: mixed solution of toluene and methyl ethyl ketone (4: 1)) was applied. Then, it was left for 2 hours in a desiccator.

Next, as shown in FIG. 6 (b), both ends 25a, 25b of a polyethylene naphthalate (PEN) balloon tube 24 (length 3 cm, outer diameter 1.4 mm, thickness 0.05 mm).
The adhesive portions 23a and 23b of the PE tubes 21a and 21b are inserted into the (width L: 3 mm), and the adhesive portions 23a and 23b are inserted.
The portion b was thermocompressed from the outer surface side at 140 ° C. for several seconds to obtain a simulated balloon catheter 26.

Next, as shown in FIG. 6 (c), one end of this simulated balloon catheter 26 is closed by a cock (not shown), and the other end is connected to a syringe 29 connected to a pressurizing device 28. did. Then, the mixture liquid (1: 1) of the contrast agent and water is injected under pressure from this syringe 29, pressurized to 20 atm, and the time (pressure resistance time) until water leakage occurs is examined, and repeated under the same conditions. The average value was calculated.

The results are shown in Table 1 and the graphs in FIGS. Here, FIG. 7 is a graph showing the relationship between the irradiation time and the withstand voltage time at an irradiation output of 10 W, FIG. 8 is a graph showing the relationship between the irradiation time and the withstand voltage time at an irradiation output of 20 W, and FIG. 9 is an irradiation time at the irradiation output of 40 W. It is a graph which shows the relationship between withstand voltage time. FIG. 10 is a graph showing the relationship between the irradiation output and the breakdown voltage at an irradiation time of 60 seconds.

[0041]

[Table 1] It can be seen from FIGS. 7 to 9 that the longer the irradiation time, the longer the pressure resistance time of the balloon tube, and the larger the irradiation output, the longer the pressure resistance time of the balloon tube.
That is, irradiation time is 10 seconds to 600 seconds, irradiation output is 10W to 40W
Within the range, it is understood that the larger the irradiation time and the irradiation output are, the higher the adhesiveness between the PE tube and the PEN balloon tube and the higher the pressure resistance of the balloon tube.

Example 2 The effect of discharge gas pressure on pressure resistance was investigated as follows.

Plasma discharge was carried out in the same manner as in Example 1 while changing the discharge gas pressure under the plasma irradiation conditions shown in Table 2. The results are shown in Table 2 and the graph in FIG. Where the figure
11 is a graph showing the relationship between discharge gas pressure and pressure resistance time.

[0044]

[Table 2] From Table 2 and FIG. 11, it can be seen that as the discharge gas pressure is higher in the range of 0.01 to 0.8 torr, the pressure resistance time becomes longer, the adhesiveness between the PE tube and the PEN balloon tube and the pressure resistance of the balloon tube become higher. .

From the results of Examples 1 and 2, the irradiation time, the irradiation output, and the discharge gas pressure are appropriately selected before the adhesive is applied, and the PE shaft is pre-irradiated with plasma. By selecting time of 300 seconds or more, irradiation output of 40 W or more, discharge gas pressure of 0.5 torr or more,
It can be seen that a balloon catheter that can withstand use at 20 atmospheres for 10 minutes or longer is obtained.

Comparative Example 1 The influence of the type of discharge gas on the pressure resistance was tested as follows.

Plasma irradiation was carried out in the same manner as in Example 2 except that oxygen was used instead of argon as the discharge gas under the conditions of irradiation output of 40 W, irradiation time of 60 seconds and discharge gas pressure of 0.5 torr, and this was repeated several times. As a result, water leakage occurred below 10 atm in all cases. Comparing this result with the result of No. 15 shown in Table 2 of Example 2 (water leakage does not occur at 20 atm), it can be seen that the adhesiveness of oxygen is significantly inferior to that of argon.

[0048]

According to the present invention, since the bonding site on the surface of the polyethylene shaft is modified by performing plasma irradiation with an inert gas in advance, the bonding between the polyethylene shaft and the polyethylene naphthalate balloon is performed. And the pressure resistance of the balloon during PTCA surgery is improved, and surgery can be safely performed without danger.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a blood vessel dilatation catheter according to the present invention.

FIG. 2 is a partial cross-sectional view showing a manufacturing process of a blood vessel dilatation catheter.

FIG. 3 is an explanatory view showing a use state of a blood vessel dilatation catheter.

FIG. 4 is a partial cross-sectional view showing a method of using the blood vessel dilation catheter. (a) is a diagram showing a state where the catheter is positioned in the narrowed portion, (b) is a diagram showing a state where the narrowed portion is expanded, and (c) is a diagram showing a state where the catheter is pulled out. .

FIG. 5 is an explanatory diagram showing a plasma irradiation device. (a) is a diagram showing a state of injecting an inert gas, and (b) is a diagram showing a state of plasma irradiation.

FIG. 6 is an explanatory diagram showing a method of a pressure resistance test. It is a figure which shows the state before (a) adhesion, and is a figure which shows the method of the pressure resistance test after (b) adhesion.

FIG. 7 is a graph showing the relationship between irradiation time and breakdown voltage time.

FIG. 8 is a graph showing the relationship between irradiation time and breakdown voltage time.

FIG. 9 is a graph showing the relationship between irradiation time and breakdown voltage time.

FIG. 10 is a graph showing the relationship between irradiation output and breakdown voltage time.

FIG. 11 is a graph showing the relationship between discharge gas pressure and pressure resistance time.

[Explanation of symbols]

 2 Balloon catheter 3 Shaft 4 Balloon 15,15 Adhesion site

Claims (1)

[Claims] 1. A balloon catheter is formed by previously irradiating an adhesive site on the surface of a polyethylene shaft with plasma using an inert gas, and then adhering a polyethylene naphthalate balloon to the adhesive site with an adhesive. A method for producing a characteristic vasodilator catheter.