JPH0698937A - Hot balloon catheter - Google Patents

Abstract

PURPOSE:To enable the expansion of a blood vessel of a heating system by using an ordinary catheter for PTCA. CONSTITUTION:A guide wire 1 is formed by passing a constantan wire 8 into a stainless steel pipe 6. The front ends of the stainless steel pipe 6 and the constantan wire 8 are soldered to constitute the measuring contact of a thermocouple. The outside surfaces of the stainless steel pipe 6 and the constantan wire 8 are coated with 'Teflon(R)'. The front end of the stainless steel pipe 6 has no coating and constitutes an electrode part 7. The guide wire 1 is passed into the lumen of the body of the catheter for the PTCA at the time of expanding the blood vessel. The constricted part of the blood vessel is expanded while this part is heated by inflating a balloon and passing a high-frequency current to the guide wire 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot balloon catheter used for vasodilation or the like.

[0002]

2. Description of the Related Art Conventionally, in hot balloon catheters used for vasodilation and the like, a high-frequency energizing mechanism is integrally incorporated in the shaft. That is, the flexible shaft made of polyethylene or the like is of a three-lumen type and has a lumen for inserting a guide wire and a liquid for expanding or contracting a balloon provided on the outer circumference of the distal end of the shaft. And a lumen for incorporating the high-frequency energizing mechanism. A current-carrying wire provided in this lumen is electrically connected to a coil-shaped high-frequency current-carrying electrode provided in the balloon on the outer peripheral side of the shaft. The energizing wire is electrically connected to the high frequency power source, but also constitutes a thermocouple for temperature detection. More specifically, the current-carrying wire is, for example, a combination of a copper wire having a diameter of 160 μm, which is a heating element, and a constantan wire having a diameter of 100 μm, which is a thermocouple element together with the copper wire. The guide wire is made of a stainless steel coil or the like and has flexibility.

In vasodilatation, first, a guide wire is percutaneously inserted into a blood vessel, and the tip end portion of the guide wire is positioned near the narrowed portion of the blood vessel. Then, pass the guide wire through the lumen of the shaft, insert the shaft into the blood vessel along the guide wire,
Position the balloon near the stenosis of the blood vessel. Liquid is then injected into the balloon through the lumen of the shaft to inflate the balloon. At the same time, a high frequency voltage of, for example, 13.56 MHz is applied between the electrode in the balloon and the counter electrode plate applied to the patient's back or the like via the current-carrying wire in the lumen of the shaft. As a result, the vicinity of the narrowed portion of the blood vessel is induction-heated. Thus, the constricted part of the blood vessel is expanded by the heating and the pressure applied from the inflated balloon. Then, the liquid is drained from the balloon to deflate the balloon, and then the catheter is withdrawn.

[0004]

However, in the above-mentioned conventional hot balloon catheter, the high frequency energizing mechanism is integrally incorporated in the shaft separately from the guide wire, so that there is a problem that the cost becomes high. Along with this, the shaft needs to have at least 3 lumens, and the diameter of the shaft must be increased. for that reason,
Insertion into blood vessels is also difficult. Further, since the current-carrying wire and the electrode also serving as a thermocouple are incorporated in the plastic shaft and balloon, the shaft and the balloon are weak against heat at the time of manufacturing, and the adhesion and the like are considerably troublesome.

The present invention is intended to solve such problems, and it is possible to reduce the diameter of the shaft and
It is an object of the present invention to provide a hot balloon catheter which can be manufactured easily and can be reduced in cost.

[0006]

In order to achieve the above-mentioned object, a hot balloon catheter of the present invention has a flexible shaft having a guide wire insertion lumen and a fluid circulation lumen formed therein, and a tip portion of the shaft. An inflatable and defensible balloon, which is provided on the outer peripheral side and communicates with the fluid circulation lumen, and has a high-frequency current-carrying function and an electrode portion at the distal end, which can be inserted into and removed from the guide wire insertion lumen of the shaft. A flexible guide wire to be inserted and a high frequency power source electrically connected to the guide wire are provided.

[0007]

In the hot balloon catheter of the present invention, for example, at the time of vasodilation, first, the guide wire is percutaneously inserted into the blood vessel, and the distal end portion of the guide wire is positioned near the narrowed portion of the blood vessel. Then, the guide wire is passed through the guide wire insertion lumen of the shaft, the shaft is inserted into the blood vessel along the guide wire, and the balloon is positioned near the narrowed portion of the blood vessel. Fluid is then injected into the balloon through the fluid flow lumen of the shaft to inflate the balloon. At the same time, a high frequency voltage is applied between the electrode portion at the tip and the counter electrode plate applied to the patient's back or the like via a guide wire having a high frequency energizing function. As a result, the vicinity of the narrowed portion of the blood vessel is induction-heated. Thus, the constricted part of the blood vessel is expanded by the heating and the pressure applied from the inflated balloon. After that, the fluid is removed from the inside of the balloon to deflate the balloon, and then the catheter is removed.

[0008]

EXAMPLE A first example of the hot balloon catheter of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows a guide wire 1 and FIG. 2 shows a catheter body 2, both of which are flexible and flexible. First, the structure of the guide wire 1 having a high-frequency energizing function will be described. 6 is a stainless steel pipe. This stainless steel pipe 6 consists of a dense coil, etc., and has an outer diameter of 300 μm, an inner diameter of 150 μm, and a length of 180 cm.
Is. And, on the outer surface of the stainless pipe 6,
It is plated with gold or copper to improve the electrical conductivity, and on top of that, a Teflon coating with a thickness of 10 μm is applied for the purpose of improving sliding and ensuring insulation. This Teflon coating is
It has been peeled off within the range of 2 cm at the tip of the stainless steel pipe 6,
The tip portion of this stainless steel pipe 6 serves as an electrode portion 7. Further, 8 is a constantan wire, and the constantan wire 8 has an outer diameter of 100 μm and is inserted into the stainless pipe 6. The outer surface of the constantan wire 8 is covered with Teflon to maintain the insulation with the stainless pipe 6. On the other hand, the tip of the constantan wire 8 is electrically connected to the tip of the stainless steel pipe 6 by welding, for example, soldering, and the connecting portion 9 serves as a measurement contact of the thermocouple. The guide wire 1 is electrically connected to one pole of a high frequency power source 11 which generates a high frequency current of 13.56 MHz, and the stainless steel pipe 6 and constantan wire 8 are connected to a thermometer body 12. is there. This thermometer main body 12 has a high frequency voltage generated by a high frequency power source 11 and the stainless pipe 6
And a signal separator for separating the electromotive force of the thermocouple formed of the constantan wire 8 and the like. Connected to the other pole of the high frequency power source 11 is a counter electrode plate 13 arranged on the back of the patient as shown in FIG.

Next, the structure of the catheter body 2 will be described. The catheter body 2 is a conventional PTCA (percutaneous transluminal coronary angioplasty) catheter. 16 is a tubular shaft, this shaft
16 is made of plastic such as polyethylene, has flexibility, and is of two lumens. That is, the guide wire insertion lumen 17 and the fluid circulation lumen 18 are formed in the shaft 16 so as to penetrate therethrough in the axial direction. In particular, the diameter of the guide wire insertion lumen 17 is about 400 μm. Further, an inflatable and defensible balloon 19 made of a flexible plastic is provided on the outer peripheral side of the tip end portion of the shaft 16. One end of the fluid circulation lumen 18 communicates with the inside of the balloon 19. On the other hand, the other end of the fluid circulation lumen 18 is
The indeflator is connected. The guide wire insertion lumen 17 that extends to the tip of the shaft 16 allows the guide wire 1 to be inserted and removed freely. Further, inside the balloon 19, a marker 20 made of metal such as gold, platinum or stainless is provided on the outer peripheral surface of the shaft 16.

Next, the operation of the above configuration will be described. For example, in a vasodilation operation, first, the guide wire 1 is percutaneously inserted into a blood vessel, and the distal end portion of the guide wire 1 is positioned beyond the narrowed portion of the blood vessel. Then, the guide wire 1 is passed through the guide wire insertion lumen 17 of the shaft 16, the shaft 16 is inserted into the blood vessel along the guide wire 1, and the balloon 19 is positioned at the narrowed portion of the blood vessel. Then, the guide wire 1 is pulled back, and the distal end portion of the guide wire 1 is positioned so as to overlap the marker 20 in the balloon 19. Then, a liquid is injected into the balloon 19 from the indeflator through the fluid circulation lumen 18 in the shaft 16, and the balloon 19 is inflated. Along with this, 13.56MHz between the high frequency power source 11 and the guide wire 1 and the counter electrode 13 placed on the back of the patient.
The high frequency voltage is applied. Generally, the high-frequency current flows through the path with the least resistance.
Since the outer surface of the guide wire is insulated by the Teflon coating except for its tip, electric power is emitted from the tip of the guide wire 1, that is, the electrode portion 7. Also,
Between the guide wire 1 and the peripheral wall of the shaft 16, there is blood, which is a good conductor of electricity, and it has almost no resistance. Furthermore, the high-frequency current must jump over the peripheral wall of the shaft 16, and the thickness of this peripheral wall is 0.1
Since it is less than mm and made of polyethylene, a sufficient condenser effect occurs, and the electric power jumps over the shaft 16 and enters the balloon 19. Here, most of the high frequency current (about 90% or more) is once transferred to the marker 20 on the shaft 16.
Then, as in the case of the conventional hot balloon catheter, the squeezed part is warmed, and then it comes out to the counter electrode plate 13. The narrowed portion of the blood vessel is expanded by the induction heating due to such high-frequency current application and the pressure applied from the inflated balloon 19. In order to perform sufficient heating, it is necessary to energize the guide wire 1 with high frequency (about 100 W) higher than that in the conventional hot balloon catheter. Further, the temperature of the connecting portion 9 between the stainless steel pipe 6 and the constantan wire 8 of the guide wire 1 forming the thermocouple, that is, the measurement contact is measured based on the electromotive force with the reference contact as the reference, and the heating temperature is changed accordingly. Is controlled. After that, the liquid is drained from the balloon 19 by an indeflator, the balloon 19 is contracted, and then the catheter is pulled out.

According to the structure of the above-mentioned embodiment, the catheter wire 2 can be used as it is as a conventional PTCA balloon catheter because the guide wire 1 also serves as the high-frequency energizing mechanism. Moreover, several types of catheter bodies can be used for the same guide wire 1, and the development cost is significantly reduced. In addition, since the guide wire 1 and the catheter body 2 are separate, manufacturing is facilitated and the cost can be significantly reduced.
Further, the lumens 17 and 18 may be the two shafts 16, and the thin shaft 16 can be used, and therefore the insertion into the blood vessel can be facilitated.

Next, the guide wire 31 of the second embodiment of the present invention will be described with reference to FIG. In addition,
Catheter body 2 into which this guide wire 31 is inserted
May be the one shown in FIG. 2 described above. 32 is a stainless steel pipe, and this stainless steel pipe 32 has an outer diameter of 300 μm
, Inner diameter 150 μm, length 150 cm. The entire outer surface of the pipe 32 is coated with Teflon.
Furthermore, the tip of the pipe 32 has an outer diameter of 400 μm and an inner diameter of 150 μm.
A gold ring 33 of μm and length of 10 mm is coaxially and seamlessly fixed by laser welding. The gold ring 33 is not insulated by Teflon, serves as an electrode portion, and
It also serves as a marker. The inside of the pipe 32 has an outer diameter of 100 μm with Teflon coating on the outer surface.
The constantan wire 34 is inserted, and the tip of the constantan wire 34 is welded to the gold ring 33.

The vasodilation is performed in the same manner as in the first embodiment. That is, first, the guide wire
Insert 31 into the blood vessel and position the tip of guide wire 31 beyond the narrowed portion of the blood vessel. Then, the guide wire 31 is passed through the shaft 16 and the shaft 16 is inserted into the blood vessel to position the balloon 19 at the narrowed portion of the blood vessel. Then, the guide wire 31 is pulled back, and the tip end portion of the guide wire 31 is positioned so as to overlap the marker 20 in the balloon 19. At that time, as in the first embodiment, the guide wire 31 must be adjusted so that the gold ring 33 of the guide wire 31 and the marker 20 of the shaft 16 are parallel and face each other as much as possible. In addition, the operation of the guide wire 31 and the shaft 16 as described above is performed by the X
Although it is performed while looking at the marker 20 and the gold ring 33 with a line imaging device, gold has significantly poorer X-ray permeability than stainless steel, so when the heart is imaged, the gold ring 33 appears to be clearly visible and guides. It is advantageous in the operation of the wire 31. After that, the balloon 19 is inflated, and a high frequency current of 13.56 MHz is applied from the high frequency power source 11 between the guide wire 1 and the counter electrode plate 13 applied to the back of the patient. At this time, since the outer surface of the stainless tube 32 is insulated by Teflon coating, the gold ring 33, which is the electrode part, is
Power will be emitted from the. In addition, there is blood between the guide wire 31 and the peripheral wall of the shaft 16, which hardly causes resistance. Furthermore, the high-frequency current is a thin polyethylene shaft due to the condenser effect.
The electric power jumps over the peripheral wall of 16 and jumps over the shaft 16 into the balloon 19. Where most of the high frequency current (about
90% or more) once jumps to the marker 20 on the shaft 16 and then passes through the counter electrode plate 13 while warming the narrowed part. The narrowed portion of the blood vessel is expanded by the induction heating due to such high-frequency current application and the pressure applied from the inflated balloon 19. In order to perform sufficient heating, it is necessary to energize the guide wire 1 with high frequency (about 100 W) higher than that in the conventional hot balloon catheter. Then, the balloon 19 is deflated and the catheter is withdrawn.

The second embodiment as described above is more practical than the first embodiment.

The present invention is not limited to the above embodiment, but various modifications can be made. For example,
In the above embodiment, the shaft having two lumens is used, but it is also possible to use a shaft having three or more lumens.

[0016]

According to the present invention, a shaft having a lumen for inserting a guide wire and a lumen for fluid flow, a balloon provided at the tip of this shaft, and a high frequency energizing function and an electrode portion at the tip. A guide wire that is removably inserted into the guide wire insertion lumen, and a high-frequency power source that is connected to this guide wire, and by using both the guide wire and the high-frequency energizing mechanism, a shaft, a balloon, etc. The catheter body made of can use the conventional PTCA balloon catheter as it is, and can be manufactured easily and the cost can be significantly reduced. Also, with two lumens, the diameter of the entire shaft can be reduced,
Therefore, it can be easily inserted into a blood vessel.

[Brief description of drawings]

FIG. 1 is a sectional view of a guide wire showing a first embodiment of a hot balloon catheter of the present invention.

FIG. 2 is a sectional view of the catheter body of the same.

FIG. 3 is a schematic side view showing a usage state of the same.

FIG. 4 is a sectional view of a guide wire showing a second embodiment of the hot balloon catheter of the present invention.

FIG. 5 is a cross-sectional view showing a state in which a guide wire is passed through the catheter body of the same.

[Explanation of symbols]

 1 Guide wire 7 Electrode part 11 High frequency power supply 16 Shaft 17 Guide wire insertion lumen 18 Fluid distribution lumen 19 Balloon 31 Guide wire 33 Gold ring (electrode part)

Claims (1)

[Claims] 1. A flexible shaft having a guide wire insertion lumen and a fluid distribution lumen formed therein,
An inflatable and defensible balloon which is provided on the outer peripheral side of the tip of the shaft and communicates with the lumen for fluid circulation, and a lumen for inserting a guide wire of the shaft which has a high-frequency energizing function and an electrode section at the tip. A hot balloon catheter comprising: a flexible guide wire that is removably inserted into the guide wire; and a high-frequency power source that is electrically connected to the guide wire.