JPH07100214A - Balloon catheter - Google Patents

Abstract

PURPOSE:To provide a balloon catheter capable of treating a lesion by selectively obtaining a contact with a part of the biotissues in contact with the balloon of a catheter and subjecting this part to rapid and local high-frequency heating. CONSTITUTION:This balloon catheter 1 has the freely contractable and shrinkable balloon 3 at its front end. An electrode 4 for high-frequency heating and a temp. sensor 5 are installed to the wall of this balloon 3. The lesion is heated by supplying high frequencies to this electrode 4 and is thus treated while the heating temp. is kept monitored by the temp. sensor 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cardiovascular balloon catheter, and more particularly to a dissecting aneurysm, an arteriosclerotic lesion of a coronary artery or a peripheral artery, a pathological atrial muscle, ventricular muscle, or valvular heart valve which becomes an arrhythmic source. The present invention relates to a balloon catheter for locally treating a lesion of a stenotic lesion by locally high-frequency heating while pressurizing the lesion.

[0002]

2. Description of the Related Art Conventional balloon catheters employ a method of treating a lesion by providing a monopolar or bipolar electrode on a shaft at the center of the balloon having a high frequency heating effect.

That is, as shown in the longitudinal sectional view of FIG. 9, a balloon 23 which can be inflated and deflated is provided at the tip of a catheter 21, and an electrode 24 for high-frequency heating is provided inside the balloon 23. The balloon 23 is inflated while the vascular occlusion part is heated by applying a high frequency to the electrode 24 to heat it (see, for example, JP-A-2-68073).

[0004]

However, according to such a conventional method for treating a lesion by using a balloon catheter, the entire balloon is heated, and the heat is propagated to the entire living tissue in contact with the balloon. It is not possible to selectively cauterize specific parts of the tissue that come into contact with.

Further, the irradiated high frequency is radiated from the electrode in the center of the balloon, so that when the shape of the balloon becomes large and the distance between the electrode and the balloon contact surface becomes large, it takes too much time to heat the tissue. There was a flaw.

Therefore, in the above-mentioned conventional balloon catheter, a large balloon having a shape for treating a dissecting aortic aneurysm cannot be instantaneously heated, and a specific portion of the tissue cannot be selectively cauterized. There was a risk of heating and blocking. It was also impossible to selectively cauterize only arteriosclerotic lesions, pathological heart muscles, or commissures of valvular membranes.

The present invention has been made in view of the above problems of the conventional balloon catheter, in which a part of the tissue in contact with the balloon is locally and rapidly heated with high frequency to cause the lesion as described above. It is an object of the present invention to provide a balloon catheter capable of treating the above.

[0008]

An inflatable and defensible balloon made of a resin is provided at the distal end of a catheter shaft through which a guide wire can pass, and an electrode for high-frequency heating and a temperature sensor are provided in or on the wall of the balloon. And are installed to form a balloon catheter.

[0009]

[Function] In a state in which the balloon of the catheter is deflated, it is inserted into the lesion area by using the guide wire provided at the tip of the catheter, and the balloon is inflated to bring the portion inside the balloon wall or the portion where the electrode is provided on the inner wall into contact with the lesion area. At the same time, a high frequency current of a predetermined frequency is passed between the balloon electrode and the counter electrode on the body surface. As a result, a high-frequency electric field is generated between the electrode and the surrounding tissue through the balloon wall made of a resin that is a derivative, and the lesion is locally pressurized and simultaneously heated according to the principle of high-frequency induction heating. . At this time, the temperature of the balloon membrane is monitored by a temperature sensor installed on the balloon wall, and the high frequency output is adjusted so that the temperature becomes an appropriate temperature.

[0010]

Embodiments of the balloon catheter of the present invention will be described below with reference to the accompanying drawings. (Example 1) FIG. 1 shows Example 1 of the balloon catheter of the present invention and shows an example applied to a balloon catheter for treating a dissecting aortic aneurysm.

As shown in FIG. 1, the balloon catheter 1 according to the first embodiment has a radiopaque Teflon catheter shaft 2, and a guide wire is provided in the catheter shaft 2 so that the catheter wire 2 can easily pass through a blood vessel stenosis. A balloon 3 having a wall surface made of a material capable of expanding and contracting is formed at the distal end of the catheter shaft 2.
The shape of the balloon 3 is made to match the shape of the patient's aortic arch. As shown in FIGS. 1 and 3, the balloon 3 has a mesh-like or membranous thin electrode 4 over the entire circumference or a part (there is no electrode on a white background) of the arterial bifurcation, as shown in FIGS. Is embedded and incorporated. The mesh-shaped electrode 4 functions as an electrode for high frequency heating. For example, if the wall thickness of the balloon 3 is 0.2 mm, the electrode 4 is made of a material such as gold having a diameter of about 0.05 mm between the walls, which is flexible, malleable and conductive.
Is configured. Therefore, the balloon 3 can freely expand and contract. In addition, these mesh electrodes 4
All the ends of the cable are converged at one place and electrically connected to the high frequency electric wire 6 loaded in the catheter shaft 2.

The high-frequency power transmission line 6 is connected to a high-frequency generator 9 (for example, a frequency of 13.56 MHZ), and the generated high-frequency current is embedded in the balloon 3 to form a mesh electrode 4.
Can be transmitted to. Further, a contrast agent is injected from a syringe 11 into the balloon 3 via a liquid supply path provided in the catheter shaft 2 so that the balloon 3 can be inflated. In addition, a temperature sensor 5 is attached at an appropriate position on the wall surface of the balloon 3 to detect the temperature of the wall surface, and the wall surface of the balloon 3 is connected to the temperature monitor 10 via a copper wire 12 connected to the temperature sensor 5. The temperature of can be monitored.

On the other hand, the copper wire 8 extending from the other side of the high frequency generator 9 is connected to the counter electrode plate 7. The counter electrode plate 7 is mounted on the front side or the back side of the living body and is one terminal for allowing a high-frequency current to flow in the living body to locally heat the treatment portion by a high-frequency induction heating method.

Next, the case of locally treating the lesion of the cardiovascular region using the balloon catheter of the first embodiment of the present invention thus constructed will be described.

First, as shown in FIG. 1, the balloon 3 is inserted into the aortic cavity with the guide wire 13 in a deflated state, and the syringe is inserted into the balloon 3 prepared in accordance with various forms of the cardiovascular cavity. A contrast agent is injected from 11 to inflate the balloon 3 to bring it into contact with a living tissue. Then, a high frequency of 10 MHZ or more is supplied from the high frequency generator 9 through the high frequency electric wire 6 and the copper wire 8 between the mesh electrode 4 and the counter electrode 7 installed in the wall of the balloon 3 or on the inner wall. Here, since a dielectric material called the film (inner wall) of the balloon 3 made of resin is interposed between the mesh electrode 4 and the counter electrode plate 7, high frequency induction type heating is performed.

By this dielectric heating, the membrane of the balloon 3 in which the electrode 4 is embedded and the living tissue with which it contacts are heated. For example, when this living tissue is the aortic wall, heat is generated in the aortic wall.

Here, the heating temperature reaches 60 ° C. or higher in a few seconds. Therefore, for example, the dissociation cavity is repaired and closed due to the synergistic action of the pressure on the dissociated aorta wall from the inside of the wall due to the expansion of the balloon 3 and the heat welding due to the heat generation.

In this case, since the temperature sensor 5 is installed at an appropriate position on the wall surface of the balloon 3, the temperature of the wall surface of the balloon 3 detected by the temperature sensor 5 is monitored by the temperature monitor 10, and the temperature of the balloon 3 is maintained. The output of the high frequency generator 9 is controlled so that the temperature is in an appropriate temperature range (for example, 60 ° C. to 70 ° C.). As a result, evaporation and carbonization of the living tissue due to excessive heating can be prevented, and the dissociation portion can be safely heat-welded. Further, the high-frequency current-carrying balloon electrode is covered with a balloon made of a resin having a smooth surface, and it does not come into direct contact with blood or tissue, so that the formation of a thrombus at the time of power supply is prevented. (Example 2) Fig. 4 shows an example of a balloon catheter for treating atrial fibrillation. Fig. 4 (a) shows a balloon for the right atrium and Fig. 4 (b) shows a balloon for the left atrium. At the tip of the catheter shaft 2a, balloons 3a and 3b having a shape designed for a right atrium or a left atrium and obtained from a contrast image are attached.

These balloons 3a, 3b are embedded with linear electrodes 4a, 4b which partially cauterize the atrial wall for forming a passage in the atrial wall and treating atrial fibrillation. For example, the electrode 4a rising linearly from the valve annulus is shown in FIG.
As shown in (a), avoid the sinus and atrioventricular junction,
As shown in FIG. 4 (b), they are arranged avoiding the pulmonary veins. When this electrode is energized with a high frequency from a high frequency generator, the inside of the atrium is cauterized in a strip shape, and it is possible to prevent the formation of an excitatory circuit that causes atrial fibrillation. (Embodiment 3) FIG. 5 shows an embodiment of a balloon catheter having a high-frequency electrocautery function in which the present invention is applied to dilate a stenotic portion of valvular heart disease. Here, FIG. 5A is a vertical cross section of the narrowed portion, FIG. 5B is a horizontal cross section thereof, and an example using a plate electrode is shown, and FIG. An example in which the plate electrodes are arranged in a fence shape will be described.

In this embodiment, as shown in FIGS. 5 (a) and 5 (b), a gourd-shaped balloon 3c is arranged on the catheter shaft 2a, and a plate-shaped high-frequency current is applied to the wall surface of the constricted portion at the center thereof. The contrasting agent is injected into the balloon 3c from the catheter shaft 2a so that the plate-shaped electrode 4c is located in the narrowed portion by burying the working electrode 4c and inflating it.

When treating this stenosis with a conventional balloon catheter, the valve is dehisced only by the mechanical pressure due to the expansion of the balloon, so that the normal part other than the commissure part is torn and the valve is closed. It could cause failure. However, as in this embodiment, the plate electrode 4c is embedded in the wall of the balloon 3c so as to be aligned with the constriction of the gourd-shaped balloon 3c and the commissure of the valve stenosis. When the plate-shaped electrode 4c is energized and heated at a high frequency at the same time as the expansion of the balloon 3c, the adhesive tissue is melted in the commissure and at the same time mechanical pressure can be applied to selectively rupture the commissure. Like This allows a more physiological valve formation and prevents complications of valve regurgitation.

Further, as shown in FIG. 5 (c), the plate-shaped electrodes 4c are arranged in the shape of a fence over the entire circumference of the constricted portion of the balloon 3c, and a high frequency is applied to only the electrodes in contact with the commissural portions to apply them. Warm. Which electrode is in contact with the commissure is confirmed by observing the cardiac ultrasonic tomography device while applying high frequency and low power. (Embodiment 4) FIG. 6 shows an embodiment 4 of the present invention, which is a balloon catheter having a high-frequency electrocautery function applied for dilation of an arteriosclerotic vascular stenosis lesion.

FIG. 6 shows a vertical cross section of this balloon catheter, and FIG. 7 shows its cross section (cross section taken along the line VII-VII in FIG. 6). In this embodiment, a guide wire 13 penetrates the core of the catheter shaft 2 and extends beyond the tip thereof, and a balloon 3 in the shape of a spine is arranged at the end of the catheter shaft 2 and the central circle of the balloon 3 is provided. The film-shaped high-frequency current-carrying electrode 4 is adhered to the film surface.

When the lesion is locally expanded, as shown in FIG. 8, the central part of the balloon 3 to which the high-frequency current-carrying electrode 4 is adhered is pushed into the stenosis of the blood vessel using the guide wire 13,
A high-frequency current is supplied while injecting a contrast agent into the balloon 3 from a syringe and inflating it. Then, only the vascular stenosis is heated at the same time as pressurization, the fat and connective tissue in the arteriosclerotic lesion are softened, and the vascular stenosis is easily expanded.

[0025]

As described above, according to the balloon catheter of the present invention, since the high-frequency current-carrying electrode and the temperature sensor of arbitrary shape are installed in or on the wall of the balloon of arbitrary shape which can be inflated and deflated, By the high frequency induction type heating through the catheter, the lesion can be selectively cauterized from the lumen of the cardiovascular region and ablated by the electrode at an appropriate temperature to be treated. In addition, since the high-frequency conducting electrode is covered with a balloon membrane made of a resin having a smooth surface and does not come into direct contact with tissues or blood, it is possible to minimize thrombus formation which is a side effect of high-frequency heating.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of Example 1 of a balloon catheter of the present invention.

FIG. 2 is a partially cutaway sectional view of a balloon portion of the balloon catheter shown in FIG.

FIG. 3 shows a usage state of the balloon catheter shown in FIG. 1, FIG.
(B) shows a state where the balloon is inflated.

FIG. 4 is a schematic view of an embodiment of a balloon catheter for treating atrial fibrillation, FIG. 4 (a) shows a balloon for the right atrium, and FIG. 4 (b) shows a balloon for the left atrium.

5A and 5B are schematic views of an embodiment of a balloon catheter for treating a stenotic portion of valvular heart disease, in which FIG. 5A is a vertical cross-section of the stenotic portion and FIG. FIG. 5C shows an embodiment using a plate electrode, and FIG. 5C also shows an embodiment in which the plate electrode is arranged in a fence shape along the entire circumference of the narrowed portion.

FIG. 6 is a longitudinal sectional view of a balloon catheter for dilation of an arteriosclerotic vascular stenosis lesion.

7 is a VII-VII of the balloon catheter shown in FIG.
It is a cross-sectional view of an arrow portion.

8 shows a state in which the balloon catheter shown in FIG. 6 is inserted into a vascular stenosis and a state in which it is inflated.

FIG. 9 shows a vertical cross section of a conventional balloon catheter in which a heating electrode is provided in the center of a conventional balloon.

[Explanation of symbols]

 1 Balloon Catheter 2 Catheter Shaft 3 Balloon 4 High Frequency Power Electrode 5 Temperature Sensor 7 Counter Electrode 9 High Frequency Generator 10 Temperature Monitor

Claims (5)

[Claims] 1. A catheter shaft capable of passing through a guide wire is provided with a balloon made of a resin capable of contracting and expanding, and a high-frequency heating electrode and a temperature sensor are installed in or on the wall of the balloon. Balloon catheter. 2. The balloon catheter according to claim 1, wherein the high-frequency heating electrode is a mesh-shaped or film-shaped electrode and is installed around the entire inner wall of the balloon or partially on the inner wall. 3. The high-frequency heating electrode is a plurality of linear electrodes, which are installed on the inner wall of the balloon or inside the wall while avoiding sinus node, atrioventricular node, pulmonary vein, and the like. The balloon catheter described. 4. The balloon is a gourd-shaped balloon,
The balloon catheter according to claim 1, wherein a plate-shaped electrode is installed on the constricted portion. 5. The balloon catheter according to claim 4, wherein the plate-shaped electrode is arranged in a fence shape over the entire constricted part of the balloon, and only the plate-shaped electrode in contact with the commissure part is energized with high frequency.