JP2005058503A - Ablation catheter with balloon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly introduce a balloon to a target lesion. <P>SOLUTION: In an ablation catheter with the balloon of this invention, a coil body which is a coil electrode 5 for high-frequency energizing is installed inside the balloon 2 in such an arrangement that its center axis 5a is roughly along the center axis 1a of the catheter 1. When introducing the balloon 2 into patient's body, the coil electrode 5 is wrapped in the balloon 2 contracted with the coil electrode 5 as a core and the balloon 2 and the coil electrode 5 are introduced in the form of being gathered compact. In addition, the coil body as the coil electrode 5 is shaped by helically winding a flat electric wire 5A around in such a winding method that the thickness direction of the flat electric wire 5A is the radial direction of the coil body and the outer diameter of the balloon 2 in a contracted state is made smaller than before by the use of the thin flat electric wire 5A. As a result, the balloon 2 is smoothly introduced into a target lesion inside the patient's body. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides a target lesion site by heating a target lesion site by heating with a high frequency dielectric heating and Joule heat in a state where a balloon disposed on the distal end side of the catheter is in close contact with the target lesion site in a patient. In particular, the present invention relates to a technique for introducing a balloon to a target lesion site in a patient body.

  An ablation catheter with a balloon for pulmonary vein electrical isolation described in JP-A-2002-78809 is an ablation catheter for performing cardiac arrhythmia treatment. When the pulmonary vein is electrically isolated using this ablation catheter with a balloon, as shown in FIG. 10, an inflatable / deflatable balloon 52 disposed on the distal end side of the catheter 51 is percutaneously cut into the inferior vena cava. The balloon 52 is introduced into the QA and pierced through the atrial septum Hw from the right atrium Ha of the heart HA while being pushed by the catheter 51 to reach the left atrium Hb. Then, the balloon 52 inflated by the supply of the liquid containing the contrast medium into the balloon is brought into close contact with the pulmonary vein opening Qa, and a round electric wire having a cross section of about 0.5 mm in diameter is spirally formed. A high frequency power supply 55 is applied to a coil electrode 53 for high frequency energization which is wound around and shaped into a coil body and installed in the balloon 52, and a high frequency energization coil electrode 53 and a high frequency energization outer electrode (pair) High frequency energization is performed between the electrodes 54).

  The annular peripheral edge of the pulmonary vein port Qa is cauterized as a whole by high-frequency dielectric heating and heating by Joule heat that occur in association with high-frequency energization between the high-frequency energization coil electrode 53 and the high-frequency energization outer electrode 54. Following cauterization of the pulmonary vein opening Qa, cauterization of the remaining three pulmonary vein openings Qb to Qd opened on the inner wall of the left atrium Hb is sequentially performed in the same manner. All the four pulmonary veins are electrically isolated by cauterizing the annular peripheral edge of each pulmonary vein opening Qa to Qd. When the annular peripheral edge of each pulmonary vein opening Qa to Qd is cauterized and each of the four pulmonary veins is in the form of electrical isolation, the electrical signal that causes arrhythmia is cut off and the cardiac arrhythmia is almost eliminated.

Thus, according to the ablation catheter with a balloon described in JP-A-2002-78809, the annular peripheral edge of each pulmonary vein opening Qa to Qd is cauterized as a whole, so that the cauterization is not repeated many times. At the same time, only the annular peripheral edge of each pulmonary vein opening Qa to Qd is cauterized, so that it is not necessary to cauterize an extra portion (for example, a healthy part).
Japanese Unexamined Patent Publication No. 2002-78809 (all pages of detailed description, FIGS. 1 to 6)

  However, the ablation catheter with a balloon described in the above publication has a problem that the balloon 52 cannot be smoothly introduced into the pulmonary vein opening Qa. If the balloon 52 cannot be introduced smoothly, it will be very painful for the patient, and it will take time for the doctor to treat, and the burden will be great on both the receiving side and the receiving side.

  In the case of the coil electrode 53 for high-frequency energization in which a round electric wire having a round cross section is spirally wound and shaped into a coil body, the balloon 52 is arranged so that the central axis of the coil body is substantially along the central axis of the catheter 51. When the balloon 52 is introduced into the pulmonary vein opening Qa, the high-frequency energization coil electrode 53 is wrapped in the deflated balloon 52 with the high-frequency energization coil electrode 53 as a core, and the balloon 52 and the high-frequency energization coil Although the coil electrode 53 is introduced in a compact form, the overall size of the balloon 52 deflated in such a manner as to enclose the coil electrode 53 for high-frequency energization is still considerable (outer diameter). Thus, the balloon 52 cannot be introduced smoothly.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the ablation catheter with a balloon which can introduce | transduce a balloon smoothly to the target lesion site | part in a patient's body.

  In order to achieve such an object, the present invention has the following configuration.

  That is, the ablation catheter with a balloon according to claim 1 is shaped into a coil body by spirally winding an inflatable / deflated balloon disposed on the distal end side of the catheter and a coil body. In an ablation catheter with a balloon comprising a coil electrode for high-frequency energization installed in the balloon in an arrangement in which the central axis of the catheter is substantially along the central axis of the catheter, and a temperature sensor installed in the balloon, The coil body of the coil electrode for high-frequency energization is a coil body in which a thin flat wire is thinly wound and shaped in a winding manner in which the thickness direction of the flat wire is the radial direction of the coil body. It is characterized by this.

  (Operation / Effect) When the target lesion site in the patient body is cauterized using the ablation catheter with a balloon of the invention of claim 1 (hereinafter abbreviated as “ablation catheter” where appropriate), the inflation is arranged on the distal end side of the catheter. A percutaneous balloon is introduced into the patient's body percutaneously in a deflated state, and the balloon reaches the target lesion site while being pushed by the catheter, and a liquid is introduced into the balloon via the catheter and inflated. Subsequently, the inflated balloon is brought into close contact with the target lesion site to be ablated, and high frequency power is supplied from the high frequency energizing coil electrode, and the high frequency power set separately from the high frequency energizing coil electrode at an appropriate position outside the patient's body. High-frequency energization is performed between the energizing outer electrodes. While performing heating by high-frequency dielectric heating and Joule heating, the heating temperature is detected by the temperature sensor in the balloon, and high-frequency power is supplied in a supply amount corresponding to the temperature measurement result of the temperature sensor. The heating and Joule heating temperature is controlled. As heating occurs around the balloon by this high-frequency energization, only the balloon contact portion of the target lesion site is heated together and locally cauterized. For example, if the target lesion site is the pulmonary vein opening in the left atrium of the heart, only the annular peripheral edge of the pulmonary vein opening is cauterized as a whole.

  In the case of the ablation catheter according to the first aspect of the present invention, the coil body as the coil electrode for high-frequency energization is installed in the balloon so that the central axis is substantially along the central axis of the catheter. When a balloon is introduced into a lesion site, the coil electrode for high frequency energization is wrapped in a deflated balloon with the coil electrode for high frequency energization as the core, and the balloon and the coil electrode for high frequency energization are introduced in a compact form. Further, the coil body as the coil electrode for high-frequency energization is shaped by winding a thin flat wide wire in a spiral manner with the thickness direction of the flat wire being the radial direction (radial direction) of the coil body. Therefore, the outer diameter of the coil body is reduced by using a thin flat wire, and the outer diameter of the deflated balloon is also reduced by the reduction of the outer diameter of the coil body. Because, it can be introduced from smoothly conventional balloon to a target lesion site within a patient. The reason why the electrode installed in the balloon is a coil body is that the electrode needs to be flexible so that the electrode bends following the bending of the introduction path such as a blood vessel. Therefore, the coil body referred to in the present invention is not a coil body in the electrical sense but a coil body in the mechanical sense.

  In addition, in the case of a coil body as a conventional coil electrode for high-frequency energization in which a round electric wire having a round cross section is spirally wound and shaped, the outer diameter of the coil body is twice the diameter of the round electric wire. The inner diameter of the coil body is added to the above dimensions. On the other hand, a coil body as a coil electrode for high-frequency energization according to the present invention in which a thin flat wire having a small thickness is spirally wound and shaped in such a manner that the thickness direction of the flat wire is the radial direction of the coil body. In this case, the outer diameter of the coil body is obtained by adding the inner diameter of the coil body to a dimension twice the thickness of the flat wire. Therefore, the coil body of the present invention using a thin flat wire has a higher frequency than the conventional coil body using a round wire by a size twice the difference between the diameter of the round wire and the thickness of the flat wire. At the same time, the outer diameter of the energizing coil electrode is reduced, and at the same time, the outer diameter of the deflated balloon is reduced by the amount of the reduced outer diameter of the high-frequency energizing coil electrode.

  In addition, since the difference between the diameter of the round electric wire and the thickness of the flat electric wire is not so large, the outer diameter of the deflated balloon is not so small as compared with the conventional case. However, even in the case of a deflated balloon, the inside of the blood vessel is pushed in an extremely cramped situation, so that the introduction of the balloon becomes much smoother if the outer diameter of the balloon is slightly reduced. In addition, when a round electric wire is simply made thin, since a current generated by a high frequency generates heat when flowing through the electric wire, such a coil body is inconvenient.

  The invention of claim 2 is the ablation catheter with balloon of claim 1, wherein the thickness of the flat wire is in the range of 0.05 mm to 0.2 mm.

  According to the invention of claim 2, since the thickness of the flat wire is sufficiently thin, 0.05 mm to 0.2 mm, the outer diameter of the coil body and the outer diameter of the deflated balloon are sufficiently small. The balloon can be introduced very smoothly into the target lesion site in the patient. When the thickness of the flat wire exceeds 0.20 mm, it is difficult to obtain the effect of reducing the diameter of the coil body by the flat wire. Conversely, when the thickness of the flat wire is less than 0.05 mm, the necessary strength as an electrode is secured. It becomes difficult.

  The invention of claim 3 is the ablation catheter with balloon according to claim 1 or 2, wherein the catheter is concentrically threaded so that the outer tube shaft and the inner tube shaft are movable in the axial direction. It is a tubular catheter, the tip of the balloon is fixed to the tip of the inner cylinder shaft, the rear end of the balloon is fixed to the tip of the outer cylinder shaft, and the coil electrode for high-frequency energization is connected to the inner cylinder shaft Is extrapolated concentrically.

  According to the invention of claim 3, in addition to being able to change the shape of the balloon in various ways by moving the outer cylinder shaft or the inner cylinder shaft in the axial direction, the coil electrode for high-frequency energization Is concentrically extrapolated to the inner cylinder shaft so that the central axis of the coil body automatically aligns with the central axis of the catheter, and the coil electrode for high-frequency energization is substantially integrated with the inner cylinder shaft. This will make the introduction of the balloon smoother.

  According to a fourth aspect of the present invention, in the ablation catheter with a balloon according to the third aspect, the coil electrode for high-frequency energization is extrapolated without restricting the inner cylindrical shaft and is fixed to the outer cylindrical shaft side. In addition, the temperature sensor is fixed to the coil electrode for high frequency energization.

  (Operation / Effect) According to the invention of claim 4, the inner cylindrical shaft can move smoothly without being restricted by the coil electrode for high-frequency energization. Furthermore, since the coil electrode for high-frequency energization is fixed to the outer tube shaft to which the rear end of the balloon is fixed, and the temperature sensor is fixed to the coil electrode for high-frequency energization, The installation position of the coil electrode and the temperature sensor is stabilized.

  Further, the invention of claim 5 is the ablation catheter with balloon according to any one of claims 1 to 4, wherein the temperature is measured from a power supply lead wire for supplying high frequency power to the coil electrode for high frequency energization and a temperature sensor. Each of the sensor lead wires for taking out signals is passed through the catheter with an electrically insulating protective coating.

  (Operation / Effect) According to the invention of claim 5, the sensor lead wire for taking out the temperature measurement signal from the temperature sensor and the power feeding lead wire for feeding the high frequency power to the coil electrode for high frequency energization are drawn to the catheter. Since it is passed, the catheter can also serve as a lead wire pipe. In addition, since both the sensor lead wire and the power supply lead wire have an electrically insulating protective coating, there is no risk of short-circuit between the lead wires, and at the same time, leakage and intrusion of high-frequency power can be suppressed. As a result, the heat generation of the catheter due to leakage and intrusion of high-frequency power is suppressed, and the forced cooling mechanism of the catheter can be omitted.

  According to a sixth aspect of the present invention, in the ablation catheter with a balloon according to the fifth aspect, the electrically insulating protective coating of the power supply lead wire is made of a material having a relative dielectric constant smaller than that of polyvinyl chloride.

  (Operation / Effect) According to the invention of claim 6, the electrical insulating protective coating of the power supply lead wire is made of a material having a relative dielectric constant smaller than that of polyvinyl chloride, and the electrical insulating protective coating has an electrical insulating property. As a result, leakage / intrusion of high-frequency power is further suppressed, and heat generation of the catheter due to leakage / intrusion of high-frequency power is sufficiently suppressed.

  According to a seventh aspect of the present invention, in the ablation catheter with a balloon according to the fifth aspect, the electrically insulating protective coating of the sensor lead wire is made of a material having a relative dielectric constant smaller than that of polyvinyl chloride.

  According to the invention of claim 7, the electrical insulating protective coating of the sensor lead wire is made of a material having a relative dielectric constant smaller than that of polyvinyl chloride, and the electrical insulating property of the electrical insulating protective coating is increased. In addition, heat generation of the catheter due to leakage / invasion is sufficiently suppressed.

  The invention according to claim 8 is the ablation catheter with a balloon according to any one of claims 1 to 7, wherein a forced cooling mechanism for the catheter is not provided.

  (Operation / Effect) According to the invention of claim 8, since the forced cooling mechanism of the catheter is omitted, it is possible to make the catheter thinner so that the catheter can be easily inserted into the patient.

  The invention of claim 9 is the ablation catheter with a balloon according to any one of claims 1 to 8, wherein the inflated balloon has a conical outer shape whose diameter is reduced on the distal end side. is there.

  (Operation / Effect) According to the invention of claim 9, since the balloon has a conical outer shape whose diameter is reduced on the distal end side, for example, the target lesion site to be ablated is the annular peripheral portion of the pulmonary vein opening. In some cases, by inserting the tip of the balloon a little into the pulmonary vein opening, the balloon can be tightly attached to the pulmonary vein opening, so that the entire annular peripheral edge of the pulmonary vein opening can be cauterized reliably. Moreover, since it is prevented from being inserted into the pulmonary vein, stenosis caused by internal cauterization can be prevented.

  The invention of claim 10 is the ablation catheter with a balloon according to any one of claims 1 to 9, wherein the liquid feeding means for feeding the liquid into the balloon via the catheter and the temperature measurement result of the temperature sensor. Power supply means for supplying high-frequency power with a supply amount according to the above.

  According to the invention of claim 10, the balloon can be inflated by supplying the liquid from the liquid introduction port into the balloon via the catheter by the liquid supply means. In addition, the heating temperature of the high-frequency dielectric heating and Joule heat can be accurately controlled by supplying high-frequency power with a supply amount corresponding to the temperature measurement result of the temperature sensor by the power supply means.

  According to an eleventh aspect of the present invention, in the ablation catheter with a balloon according to the tenth aspect, the liquid fed by the liquid feeding means passes through a clearance between the outer cylinder shaft and the inner cylinder shaft.

  (Operation / Effect) According to the invention of claim 11, the clearance between the outer cylinder shaft and the inner cylinder shaft can be used as a flow path for liquid feeding by the liquid feeding means.

  The invention of claim 12 is the ablation catheter with balloon according to claim 10 or 11, wherein the liquid in the balloon inflated by the liquid fed from the liquid introduction port by the liquid feeding means is supplied to the catheter and the balloon. And a liquid agitating means for agitating the liquid in the balloon.

  According to the twelfth aspect of the present invention, the liquid in the balloon in an inflated state is introduced between the catheter and the balloon by the liquid agitating means during the execution of the heating by the high frequency dielectric heating and the Joule heat. When the liquid inside the balloon is moved in and out and the liquid inside the balloon is agitated, liquids with different temperatures are mixed together to make the liquid temperature inside the balloon uniform, and heating unevenness due to high frequency dielectric heating and Joule heat can be suppressed.

  As described above, according to the ablation catheter with a balloon according to the first aspect of the present invention, the coil body as the coil electrode for high-frequency energization is installed in the balloon so that the central axis is substantially along the central axis of the catheter. When a balloon is introduced into a target lesion site in a patient, the high frequency energizing coil electrode is wrapped in a deflated balloon with the high frequency energizing coil electrode as a core, and the balloon and the high frequency energizing coil electrode are compactly assembled. In addition to being introduced in the form, a coil body as a coil electrode for high-frequency energization is wound in a spiral manner with a thin flat wire having a thin thickness and the thickness direction of the flat wire being the radial direction of the coil body. The outer diameter of the balloon, which has been shaped and is deflated by the reduction of the coil body diameter, by using a flat wire with a thin coil body diameter. Becomes smaller, it can be introduced much smoother than conventional balloon to a target lesion site within a patient.

  Hereinafter, embodiments of the ablation catheter with a balloon according to the present invention will be described. FIG. 1 is a plan view showing the overall configuration of the ablation catheter according to the embodiment, FIG. 2 is a cross-sectional view showing the inside of the balloon of the ablation catheter of the embodiment, and FIG. FIG. The ablation catheter of this embodiment is suitable for performing pulmonary vein electrical isolation as a treatment for cardiac arrhythmia.

  In the ablation catheter of the embodiment, a balloon 2 that can be inflated and deflated is disposed on the distal end side of the catheter 1. The catheter 1 is a double tube type catheter in which an outer tube shaft 3 and an inner tube shaft 4 are concentrically threaded so as to be movable in the axial direction, and the distal end portion of the balloon 2 is fixed to the distal end of the inner tube shaft 4. The rear end portion of the balloon 2 is fixed to the front end of the outer cylinder shaft 3, and a liquid introduction port 2A is provided at the rear end of the balloon. In the case of the double tube type catheter 1, the shape of the balloon 2 can be variously changed by moving the outer tube shaft 3 or the inner tube shaft 4 in the axial direction. Therefore, in the present invention, the catheter 1 is preferably a double tube catheter, but the catheter 1 is not necessarily limited to a double tube catheter, and a single tube catheter is preferable depending on the type of treatment. There is also.

  The length of the outer cylinder shaft 3 and the inner cylinder shaft 4 is about 1 m to about 1 m and several tens of centimeters. The outer diameter of the outer cylinder shaft 3 is about 3 mm to 5 mm, and the inner diameter is about 2 mm to 4 mm. The outer diameter of the inner cylinder shaft 4 is about 1 mm to 3 mm, and the inner diameter is about 0.5 mm to 2 mm. As the material of the outer cylinder shaft 3 and the inner cylinder shaft 4, a flexible material having excellent antithrombogenicity is used. Specifically, a fluororesin, a polyamide resin, a polyimide resin, etc. are mentioned, for example.

  As shown in FIG. 3, the balloon 2 has a conical shape (conical tip conical shape) whose diameter is reduced on the distal end side in the inflated state. The balloon 2 has a length (length d along the balloon center axis 2a that virtually connects the balloon tip and the balloon rear end) of about 20 mm to 40 mm, and the maximum outer diameter on the rear end side is about 10 mm to 40 mm. The film thickness is 100 μm to 300 μm. When the outer diameter of the balloon 2 has a conical shape with a tapered shape, the balloon can be prevented from entering the pulmonary vein, and the balloon 2 can be inserted into the pulmonary vein mouth by slightly inserting the tip of the balloon 2 into the pulmonary vein mouth. Since it is closely attached, the entire annular peripheral edge of the pulmonary vein opening can be reliably cauterized.

  As the material of the balloon 2, a stretchable material excellent in antithrombogenicity is used. Polyurethane polymer materials are particularly preferred, and specific examples include thermoplastic polyether urethane, polyether polyurethane urea, fluoropolyether urethane urea, polyether polyurethane urea resin, polyether polyurethane urea amide, and the like.

  Furthermore, in the case of the ablation catheter of the embodiment, a coil electrode for high-frequency energization (hereinafter abbreviated as “coil electrode” as appropriate) 5 is installed in the balloon 2, and liquid is supplied into the balloon 2 from the liquid inlet 2 </ b> A. Is fed via the four-way connector CN to the distal end side of the catheter 1.

  The coil electrode 5 for high-frequency energization is formed into a coil body by winding a thin flat wire 5A having a small thickness spirally, and the central axis 5a of the coil body is substantially along the central axis 1a of the catheter 1. In addition to being arranged in the balloon 2 in the arrangement, in the coil body as the coil electrode 5, the flat electric wire 5A is spirally wound in such a manner that the thickness direction of the flat electric wire 5A is the radial direction of the coil body. It is wound.

  Therefore, as shown in FIGS. 6 and 7, the outer diameter P of the coil body, which is the coil electrode 5, is obtained by adding the inner diameter P2 of the coil body to a dimension twice the thickness P1 of the flat electric wire 5A. As shown in FIGS. 8 and 9, the conventional coil electrode 53 is formed by spirally winding a round electric wire 53A having a perfectly circular cross section, so that the outer diameter Q of the coil body as the coil electrode 53 is shaped. Is obtained by adding the inner diameter Q2 (= P2) of the coil body to a size twice the diameter Q1 of the round electric wire 53A. Therefore, the coil body of the coil electrode 5 using the flat electric wire 5A has a diameter Q1 of the round electric wire 53A and a thickness P1 of the flat electric wire 5A as compared with the coil body of the conventional coil electrode 53 using the round electric wire 53A. The outer diameter of the coil electrode 5 is reduced by a dimension twice as large as the thickness difference (Q1-P1).

  The thickness P1 of the flat electric wire 5A is suitably in the range of 0.05 mm to 0.2 mm from the viewpoint of ensuring the diameter reduction effect of the coil body by the flat electric wire 5A and at the same time ensuring the necessary strength as an electrode. If the thickness P1 of the flat electric wire 5A exceeds 0.20 mm, it is difficult to obtain the effect of reducing the diameter of the coil body by the flat electric wire 5A, and conversely, if the thickness P1 of the flat electric wire 5A is less than 0.05 mm, the necessary strength as an electrode It becomes difficult to secure. The width of the flat electric wire 5A is not limited to a specific width, but usually about 0.5 mm to 3 mm is appropriate. As the wire of the flat electric wire 5A, a highly conductive metal wire such as a silver wire, a gold wire, a platinum wire, or a copper wire is used.

  The coil electrode 5 is concentrically inserted on the inner cylinder shaft 4 without restricting the inner cylinder shaft 4. The inner diameter of the coil electrode 5 is slightly larger than the outer diameter of the inner cylindrical shaft 4, and there is a slight gap between the inner surface of the coil electrode 5 and the outer surface of the inner cylindrical shaft 4. When the coil electrode 5 is concentrically inserted on the inner tube shaft in this way, the center axis 5a of the coil body automatically aligns with the center axis 1a of the catheter 1, and the coil electrode 5 It becomes substantially integrated with the inner cylinder shaft 4. Moreover, since the coil electrode 5 does not restrain the inner cylinder shaft 4, the inner cylinder shaft 4 can be moved smoothly.

  A planar electrode is used as a high-frequency energizing outer electrode (hereinafter abbreviated as “outer electrode” as appropriate) 7 separately set as a counter electrode of the coil electrode 5 at an appropriate position outside the patient's body. Examples of the material of the outer electrode 7 include copper and aluminum high-conductivity thin metal plates. During heating by high-frequency dielectric heating and Joule heat, heating is performed by applying high-frequency current between the coil electrode 5 and the outer electrode 7. The appropriate temperature for tissue cauterization during high frequency dielectric heating and Joule heating is usually in the range of 50 ° C to 70 ° C.

  On the other hand, the liquid feeding device 6 is provided with a liquid feeding roller pump (not shown), and the liquid fed by the liquid feeding roller pump passes through the clearance between the outer cylinder shaft 3 and the inner cylinder shaft 4. Then, it is fed into the balloon 2 from the liquid inlet 2A. As the liquid from the liquid feeding device 6 is fed into the balloon 2, the balloon 2 is inflated. That is, the clearance between the outer cylinder shaft 3 and the inner cylinder shaft 4 is used as a flow path for liquid feeding by the liquid feeding device 6.

  In the case of the ablation catheter of the embodiment, a diaphragm type liquid agitating mechanism for agitating the liquid in the balloon 2 by allowing the liquid in the balloon 2 in an inflated state by liquid supply to enter and exit the balloon 2 via the catheter 1 ( Liquid stirring means) 8 is provided. By the stirring by the stirring mechanism 8, liquids having different temperatures are mixed to make the liquid temperature in the balloon uniform, and heating unevenness due to high frequency dielectric heating and Joule heat can be suppressed.

  Furthermore, in the ablation catheter of the embodiment, a temperature sensor 9 installed in the balloon 2, a high-frequency power source (power supply means) 10 that supplies high-frequency power with a supply amount corresponding to the temperature measurement result of the temperature sensor 9, and It has. The frequency of the high-frequency power ranges from several MHz to several hundred MHz, and is usually around 10 MHz. During execution of heating by high-frequency dielectric heating and Joule heat, the heating temperature is detected by the temperature sensor 9 in the balloon 2 and fed back to the high-frequency power source 10, and the high-frequency power source 10 responds to the temperature measurement result of the temperature sensor 9. By supplying high-frequency power with the supply amount, the heating temperature by high-frequency dielectric heating and Joule heat is controlled.

  In addition, the coil electrode 5 is fixed to the outer cylinder shaft 3 to which the rear end portion of the balloon 2 is attached, and the temperature sensor 9 is fixed to the coil electrode 5. As a result, the installation positions of the coil electrode 5 and the temperature sensor 9 in the balloon 2 are stabilized. The temperature sensor 9 is exemplified by a thermocouple, but is not limited to a thermocouple, and for example, a semiconductor type temperature measuring element or the like can be used.

  Further, as shown in FIG. 4, both the sensor lead wire 11 for extracting a temperature measurement signal from the temperature sensor 9 and the power feeding lead wire 12 for feeding high frequency power to the coil electrode for high frequency energization are electrically insulated. With the coverings 13 and 14, the clearance between the outer cylinder shaft 3 and the inner cylinder shaft 4 of the catheter 1 is drawn through. That is, the clearance between the outer cylinder shaft 3 and the inner cylinder shaft 4 is used as piping for the sensor lead wire 11 and the power supply lead wire 12. In addition, since the sensor lead wire 11 and the power supply lead wire 12 are both provided with an electrically insulating protective coating 13, 14, there is no risk of short-circuiting between the lead wires, and at the same time, leakage of high-frequency power Intrusion is suppressed, and heat generation of the outer cylinder shaft 3 and the inner cylinder shaft 4 due to leakage and intrusion of high-frequency power is suppressed. As a result, in the case of the ablation catheter of the embodiment, the forced cooling mechanism of the catheter 1 is omitted. However, a forced cooling mechanism for the catheter 1 may be provided in the catheter 1 as necessary.

  Examples of the material of the sensor lead wire 11 and the power supply lead wire 12 include copper, silver, platinum, tungsten, alloys, and the like.

  Further, when the electrical insulating protective coatings 13 and 14 are made of a material having a relative dielectric constant smaller than that of polyvinyl chloride, the electrical insulating properties of the electrical insulating protective coatings 13 and 14 are improved. The heat generation of the outer cylinder shaft 3 and the inner cylinder shaft 4 due to leakage and intrusion of high-frequency power is further suppressed. Further, the fact that the outer cylinder shaft 3 and the inner cylinder shaft 4 are made of a material having a relative dielectric constant smaller than that of polyvinyl chloride also prevents heat generation of the outer cylinder shaft 3 and the inner cylinder shaft 4 due to leakage and intrusion of high-frequency power. It is valid.

  In the case of the embodiment, the power supply lead wire 12 also uses the same flat wire as the coil electrode 5, but the power supply lead wire 12 may use a round wire.

  As a material having a relative dielectric constant smaller than that of polyvinyl chloride, a material having a relative dielectric constant of 10 MHz at 3 or less, more preferably 10 MHz at a relative dielectric constant of 1 or less can be mentioned. This relative dielectric constant ε can be measured as follows.

ε = Cx / Co
Where Cx is the capacitance of the measuring capacitor Cs when the bridge is balanced. However, Co is a capacitance of ε = 1 calculated from the area of the main electrode and the thickness of the test piece, and is calculated by the following equation.

Co = r ² /3.6t
r: radius of main electrode (cm), t: thickness of test piece (cm)
Specific examples of materials having a lower dielectric constant than polyvinyl chloride include fluorine polymer compounds such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-6-fluoropropylene copolymer (FEP). Other examples include polyethylene, polypropylene, polyimide resin, and polyamide resin. In addition, as an apparatus used for the measurement of the dielectric constant ε, for example, an RF impedance / material analyzer (HP4291A) manufactured by Hewlett-Packard Company may be used.

  Further, radiation shielding metal pipes 3A and 4A are attached to the tips of the outer cylinder shaft 3 and the inner cylinder shaft 4, and the tip and rear ends of the balloon 2 are attached to the metal pipes 3A and 4A, respectively. The outer cylinder shaft 3 and the inner cylinder shaft 4 are fixed. By providing the radiation shielding metal pipes 3A and 4A, when X-ray fluoroscopy is performed, the radiation shielding metal pipes 3A and 4A appear on the X-ray fluoroscopic image, so that the position of the balloon 2 in the patient body can be accurately determined. It becomes possible to grasp. Examples of the material of the radiation shielding metal pipes 3A and 4A include gold, platinum, and stainless steel.

  In the case of cauterizing the annular peripheral edge of the pulmonary vein opening using the ablation catheter of the embodiment, as in the conventional case, as shown in FIG. 5, the guide wire GW previously introduced into the patient's body percutaneously. The balloon 2 in the deflated state is pushed forward by the catheter 1 and reaches the left atrium from the inferior vena cava. Then, the balloon 2 in the inflated state is placed in close contact with the pulmonary vein opening Qa, and the coil electrode 5 A high-frequency current is applied between the outer electrodes 7 to cauterize the annular peripheral edge of the pulmonary vein opening Qa.

  In the case of the ablation catheter of the embodiment having the above-described configuration, the coil body as the high-frequency energizing coil electrode 5 is installed in the balloon 2 in such a manner that the central axis 5a is substantially along the central axis 1a of the catheter 1. When the balloon 2 is introduced into the target lesion site in the patient body, the coil electrode 5 is wrapped in the contracted balloon 2 with the coil electrode 5 as a core, and the balloon 2 and the coil electrode 5 are introduced in a compact form. In addition, the coil body as the coil electrode 5 is shaped by winding the flat wire 5A spirally in a winding manner in which the thickness direction of the flat wire 5A is the radial direction of the coil body. The outer diameter of the balloon 2 is smaller than that of the prior art by using the thin flat wire 5A, and the outer diameter of the deflated balloon 2 is also reduced by the reduction of the outer diameter of the coil body. The balloon 2 into the body of the target lesion site can be introduced from the smooth conventional.

  Note that the outer diameter of the deflated balloon 2 is not so small. However, even if the balloon 2 is deflated originally, the inside of the blood vessel can be pushed in an extremely cramped situation. Therefore, if the outer diameter of the balloon 2 is slightly reduced, the introduction of the balloon 2 becomes much smoother. That is, the catheter has various sizes depending on its application, but generally 3Fr to 9Fr (3Fr = 1 mm). Therefore, in the catheter field, it is very difficult to reduce the diameter by 1 mm, and the effect of reducing the introduction resistance is very large.

  In the case of the ablation catheter with a balloon according to the embodiment, since the coil electrode 5 is concentrically inserted on the inner tube 4, the central axis 5 a of the coil body automatically matches the central axis 1 a of the catheter 1. In addition, the coil electrode 5 is substantially integrated with the inner cylindrical shaft 4 so that the balloon 2 can be introduced more smoothly.

  Next, specific examples of the ablation catheter of the present invention will be described.

  [Example] First, a balloon 2 having a conical shape with a conical tip having a length of 30 mm at the front end of the balloon and a rear end of the balloon, a maximum outer diameter of 30 mm at the rear end, and a membrane thickness of 160 μm was prepared as follows. . That is, a glass balloon mold having a mold surface corresponding to a desired balloon shape is immersed in a 13% concentration polyurethane solution, and the solvent is evaporated by applying heat to form a urethane polymer film on the mold surface. Balloon 2 was produced by the method.

  On the other hand, a polyamide resin tube having an outer diameter of 3.8 mm, an inner diameter of 2.7 mm, and an overall length of 80 cm is used as the outer cylindrical shaft 3 of the catheter 1, and a stainless steel pipe having a diameter of 3.1 mm and a length of 7 mm and a sandblasted outer surface is used. The metal pipe 3A was inserted and fitted to the tip of the tube and then tied and fixed with a 0.1 mm nylon thread, and the four-way connector CN was inserted and fitted to the rear end and then tied and fixed with a 0.1 mm nylon thread.

  On the other hand, a polyamide resin tube having an outer diameter of 1.5 mm, an inner diameter of 1.1 mm, and an overall length of 90 cm is used as the inner cylindrical shaft 4, and a stainless steel pipe having a diameter of 1.2 mm and a length of 6 mm and a sandblasted outer surface is used as the metal pipe 4A. As shown in Fig. 1, the inner end of the tube was tied and fixed with a 0.1 mm nylon thread. Then, after inserting the inner tube shaft 4 through the four-way connector CN, the cap of the four-way connector CN was tightened to produce the double tube catheter 1.

  Also, the inner diameter is 1.6mm, the length is 0.15mm, the thickness is 1.35mm, the width is 1.3mm, and the length is 1m. A coil body having a thickness of 10 mm is used as the coil electrode 5, and an electrical insulating protective coating 14 is applied to the rear portion of the coil electrode 5 using a tetrafluoroethylene-6fluoropropylene copolymer (FEP) to supply power. The lead wire 12 was used. Furthermore, as the temperature sensor 9, an ultrafine thermocouple double (copper-constantan) wire with poly (tetrafluoroethylene) and an electrically insulating protective coating 13 was prepared with a sensor lead wire 11.

  After the temperature sensor 9 is fixed to the coil electrode 5, the coil electrode 5 is fitted into the tip of the inner cylinder shaft 4, and then the sensor lead wire 11 and the power supply lead wire 12 are connected to the outer cylinder shaft 3 and the inner cylinder shaft. 4, the rear ends of the sensor lead wire 11 and the power supply lead wire 12 are pulled out from the four-way connector CN, and the sensor lead wire 11 and the tip of the power supply lead wire 12 are pulled out. This was fixed to the metal pipe 3A with an aramid fiber fixture. Finally, the tip of the balloon 2 is tied and fixed to the metal pipe 4A with 0.1 mm nylon thread, and the rear end of the balloon 2 is tied and fixed to the metal pipe 3A with 0.1 mm nylon thread. Completed an ablation catheter.

  [Comparative Example] A coil body having an inner diameter of 1.6 mm and a length of 10 mm formed by spirally winding the tip of a 0.5 mm diameter electrical copper wire (round wire) having a silver plating of 0.1 μm and forming a coil. A comparative ablation catheter was completed in the same manner as in Example except that the electrode 53 was used.

  [Outer Diameter Measurement Test] For each of the ablation catheters prepared in the following examples and comparative examples, the outer diameter (diameter) of the balloon in the deflated state (that is, the state when introduced into the patient's body) is set with a caliper. Measured. The measurement was performed 5 times and the average value was calculated.

  When the difference between the two was obtained, the result was that the outer diameter of the balloon was smaller in the example by about 0.7 mm.

  [Heating test] Subsequently, the ablation catheters of the examples were subjected to a heating test test using high-frequency dielectric heating and Joule heat by applying high-frequency energization. It was checked whether it can be heated normally. Physiological saline was placed in a sufficiently large water tank (not shown), and the liquid temperature was 37 ° C. with a heater with a stirring function, and the outer electrode was set on the peripheral wall surface of the container. And the balloon 2 of the ablation catheter of an Example was put into the water tank with the catheter 1 together. On the other hand, the sensor lead wire 11 is connected to the temperature measurement signal input terminal of the high frequency power source 10 and the power feeding lead wire 12 of the coil electrode 5 and the power feeding lead wire 15 of the outer electrode 7 are connected to the high frequency power source 10. Each was connected to a high frequency power output terminal. The high frequency power supply 10 is set so as to control the supply amount of the high frequency power so that the heating temperature becomes 70 ° C. according to the intensity of the temperature measurement signal of the temperature sensor 9. The frequency of the high frequency power is about 13.6 MHz.

  Further, the liquid feeding device 6 was connected to the four-way connector CN, and the contrast medium was fed as a liquid to the balloon 2 via the catheter 1 to inflate the balloon 2. Then, high-frequency power was supplied from the high-frequency power source 10 while operating the diaphragm stirring mechanism 8. Further, the intensity of the temperature measurement signal of the temperature sensor 9 was continuously recorded by the recorder during the supply of the high frequency power. From the recording of the recorder, it was confirmed that the heating temperature was in an appropriate temperature range centered on 70 ° C. after the initial fluctuation period. That is, it was confirmed that the heating effect does not change even when the flat wire is used because the coil surface area is almost the same.

  Therefore, according to the outer diameter measurement test and the heating test described above, according to the ablation catheter of the example, the outer diameter of the balloon 2 is reduced by the coil electrode 5 using the flat electric wire 5A. It was confirmed that the balloon 2 can be introduced more smoothly than before.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) The ablation catheter of the embodiment has a configuration including all of the liquid feeding device 6, the high-frequency power source 10, or the outer electrode 7, but the liquid feeding device 6, the high-frequency power source 10 or the outer electrode 7 is actually used. Therefore, the ablation catheter of the present invention may be a catheter that does not include the liquid delivery device 6, the high-frequency power source 10, or the outer electrode 7.

It is a top view which shows the whole structure of the ablation catheter of embodiment. It is sectional drawing which shows the inside of the balloon which concerns on embodiment. It is a front view which shows the external shape at the time of expansion | swelling of the balloon which concerns on embodiment. It is a transverse cross section of the catheter concerning an embodiment. It is a schematic diagram which shows the cauterization situation of the pulmonary vein opening by the balloon of embodiment. It is a top view of the coil electrode for high frequency energization concerning an embodiment. It is sectional drawing of the flat electric wire used for the coil electrode for high frequency electricity supply which concerns on embodiment. It is a top view of the conventional coil electrode for high frequency electricity supply. It is sectional drawing of the round wire used for the conventional coil electrode for high frequency electricity supply. It is a schematic diagram which shows the cauterization situation of the annular peripheral part of the pulmonary vein opening by the ablation catheter with a balloon.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Catheter 1a ... Center axis | shaft of catheter 2 ... Balloon 3 ... Outer cylinder shaft 4 ... Inner cylinder shaft 5 ... Coil electrode for high frequency energization 5A ... Flat wire 5a ... Center axis of coil body 6 (which is a coil electrode for high frequency energization) 6 ... Liquid feeding device (liquid feeding means)
7 ... outer electrode for high frequency energization 8 ... Diaphragm type stirring mechanism (liquid stirring means)
9 ... Temperature sensor 10 ... High frequency power supply (power supply means)
DESCRIPTION OF SYMBOLS 11 ... Sensor lead wire 12 ... Electric power supply lead wire 13, 14 ... Electrical insulation protective coating 15 ... Electric power supply lead wire

Claims (12)

  An inflatable / deflatable balloon arranged on the distal end side of the catheter, an electric wire is spirally wound and shaped into a coil body, and the central axis of the coil body is substantially along the central axis of the catheter In the ablation catheter with a balloon provided with the coil electrode for high-frequency energization installed in the balloon and the temperature sensor installed in the balloon, the coil body of the coil electrode for high-frequency energization is thin and wide. An ablation catheter with a balloon, wherein the flat electric wire is a coiled body that is spirally wound and shaped in such a manner that the thickness direction of the flat electric wire is the radial direction of the coiled body.   The ablation catheter with a balloon according to claim 1, wherein the thickness of the flat electric wire is in a range of 0.05 mm to 0.2 mm.   The ablation catheter with a balloon according to claim 1 or 2, wherein the catheter is a double-cylinder catheter in which an outer tube shaft and an inner tube shaft are concentrically connected in an axially movable manner. The distal end of the balloon is fixed to the distal end of the inner cylindrical shaft, the rear end of the balloon is fixed to the distal end of the outer cylindrical shaft, and the coil electrode for high-frequency energization is concentrically inserted into the inner cylindrical shaft. Ablation catheter with balloon.   The ablation catheter with a balloon according to claim 3, wherein the coil electrode for high-frequency energization is extrapolated in a manner that does not restrain the inner cylinder shaft and is fixed to the outer cylinder shaft side, and the temperature sensor Ablation catheter with balloon fixed to coil electrode for energization.   The ablation catheter with a balloon according to any one of claims 1 to 4, wherein a lead wire for power supply for supplying high-frequency power to the coil electrode for high-frequency energization and a sensor lead wire for extracting a temperature measurement signal from the temperature sensor are provided. Both are ablation catheters with balloons that are passed through the catheter with an electrically insulating protective coating.   The ablation catheter with a balloon according to claim 5, wherein the electrically insulating protective coating of the power supply lead wire is made of a material having a relative dielectric constant smaller than that of polyvinyl chloride.   The ablation catheter with a balloon according to claim 5, wherein the electrically insulating protective coating of the sensor lead wire is made of a material having a relative dielectric constant smaller than that of polyvinyl chloride.   The ablation catheter with a balloon according to any one of claims 1 to 7, wherein a forced cooling mechanism for the catheter is not provided.   The ablation catheter with a balloon according to any one of claims 1 to 8, wherein the balloon in an inflated state has a conical outer shape whose diameter is reduced on the distal end side.   10. The ablation catheter with a balloon according to claim 1, wherein a liquid feeding means for feeding a liquid into the balloon via the catheter and a high-frequency energization with a supply amount according to a temperature measurement result of the temperature sensor. An ablation catheter with a balloon comprising power supply means for supplying high-frequency power from a coil electrode.   The ablation catheter with a balloon according to claim 10, wherein the liquid fed by the liquid feeding means passes through a clearance between the outer cylinder shaft and the inner cylinder shaft. The ablation catheter with a balloon according to claim 10 or 11, wherein the liquid in the balloon in an inflated state is caused to enter and exit between the catheter and the balloon by the liquid fed from the liquid introduction port by the liquid feeding means. An ablation catheter with a balloon provided with a liquid stirring means for stirring the liquid.

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