JP4222152B2 - Ablation catheter with balloon - Google Patents

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. The present invention relates to an ablation catheter with a balloon that ablates, and particularly relates to a technique for constantly maintaining a heating temperature by high-frequency dielectric heating and Joule heat.

  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. 6, 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 supplying the liquid containing the contrast medium into the balloon is brought into close contact with the pulmonary vein opening Qa, and is attached to the high-frequency energizing inner electrode 53 installed in the balloon 52. High-frequency power is supplied from a high-frequency power supply 55, and high-frequency energization is performed between the high-frequency energization inner electrode 53 and the high-frequency energization outer electrode (counter electrode) 54 disposed outside the patient's body.

  The annular peripheral portion 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 inner 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 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 causing the 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, since only the annular peripheral edge of each pulmonary vein opening Qa to Qd is cauterized, it is not necessary to cauterize an extra portion (for example, a healthy part).
JP 2002-78809 A (all pages of detailed description of the invention, FIGS. 1 to 6)

  However, in the case of the ablation catheter with a balloon described in the above publication, there is a problem that the heating temperature by high frequency dielectric heating and Joule heat sometimes deviates from an appropriate range. If the heating temperature by high frequency dielectric heating and Joule heat is too high, there is a concern that thrombus formation, heart wall damage due to excessive cauterization, and pulmonary vein stenosis may occur. On the other hand, if the heating temperature is too low, there is a concern that electrical isolation may not be achieved due to insufficient shochu.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the ablation catheter with a balloon which can always maintain the heating temperature by a high frequency dielectric heating and Joule heat at a suitable temperature.

  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 disposed on the distal end side of the catheter and has an inflatable / deflatable balloon in which a liquid inlet is disposed at the rear end of the balloon, and is installed in the balloon. The inner electrode for high-frequency energization, the temperature sensor that is always located between the center of the balloon and the balloon tip in the balloon that is inflated by the introduction of the liquid from the liquid inlet, and the catheter from the liquid inlet to the balloon. Liquid supply means for supplying the liquid at a temperature, power supply means for supplying high-frequency power in a supply amount corresponding to the temperature measurement result of the temperature sensor, and liquid fed from the liquid inlet by the liquid supply means the liquid of the balloon in an inflated state is out between the catheter and balloon for stirring the liquid within the balloon liquid agitation means The is characterized in that it comprises.

  (Operation / Effect) When the target lesion site in the patient body is cauterized using the ablation catheter with 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 deflated balloon is transcutaneously introduced into the patient's body and pushed by the catheter to reach the target lesion site, and the balloon is inflated by introducing liquid from the liquid inlet at the rear end of the balloon via the catheter. . Subsequently, the inflated balloon is brought into close contact with the target lesion site to be ablated, and high-frequency power is supplied. Between the high-frequency energization inner electrode and the high-frequency energization outer electrode separately set at an appropriate position outside the patient's body. Make high-frequency energization with. 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 heating temperature is detected by the temperature sensor in the balloon during the heating by the high frequency dielectric heating and the Joule heat, and the supply amount according to the temperature measurement result of the temperature sensor. By supplying high-frequency power, the heating temperature of high-frequency dielectric heating and Joule heat is controlled. And this temperature sensor is always located between the balloon center and the balloon tip in the balloon in an inflated state due to the introduction of liquid, and there is a temperature sensor at a position away from the liquid inlet at the rear end of the balloon. During heating by high-frequency dielectric heating and Joule heat, it is difficult for the low-temperature liquid that has entered from the liquid inlet at the rear end of the balloon to touch the temperature sensor. The situation where the temperature measurement result is lower than the actual temperature is avoided, and the temperature measurement result is always accurate. Therefore, since the supply amount of the high-frequency power is always an appropriate amount based on the accurate temperature measurement result, the heating temperature of the high-frequency dielectric heating and the Joule heat is accurately controlled and always kept at an appropriate temperature.

  That is, the inventor obtained the following knowledge as a result of examining the conventional ablation catheter with a balloon from various angles. In the case of a conventional ablation catheter, a temperature sensor for detecting a heating temperature by high-frequency dielectric heating and Joule heat is in the vicinity of the liquid inlet at the rear end of the balloon. When a low-temperature liquid comes in from the liquid inlet, it is easy for the low-temperature liquid to touch the temperature sensor directly, and the temperature sensor touches the new low-temperature liquid and the temperature measurement results are actually heated. As a result of being much lower than the temperature, it was found that the supply amount of high frequency power was supplied more than necessary, and the heating temperature of high frequency dielectric heating and Joule heat became too high, resulting in an excessive cauterization. Furthermore, depending on the degree of excessive supply of high-frequency power, the supply of high-frequency power may be forcibly stopped to avoid excessive cauterization. In this case, high-frequency dielectric heating and Joule heat are sometimes insufficient. As a result, the situation of shochu is in short supply.

  Then, the inventors continued further investigation, and if the temperature sensor is always in a position in the balloon in an inflated state due to the introduction of the liquid at a position away from the liquid introduction port between the balloon center and the balloon tip, high-frequency dielectric heating and Even when low temperature liquid comes in from the liquid inlet at the rear end of the balloon during heating by Joule heat, it is difficult for the low temperature liquid to touch the temperature sensor directly, and the temperature measurement result of the temperature sensor is the actual warming. The situation that the temperature is much lower than the temperature is avoided, and the knowledge that an accurate temperature measurement result can be obtained can be obtained, and the present invention has been completed.

Therefore, according to the ablation catheter with a balloon according to the first aspect of the present invention, the temperature sensor for detecting the heating temperature is introduced by introducing the liquid while the target lesion site to be ablated is heated by high frequency dielectric heating and Joule heat. The balloon in the inflated state is always located between the center of the balloon and the tip of the balloon and away from the liquid inlet at the rear end of the balloon, so that the rear end of the balloon is heated during high-frequency dielectric heating and Joule heating. Even when a low-temperature liquid enters from the liquid inlet, it is difficult for the low-temperature liquid to touch the temperature sensor directly, and the temperature sensor's temperature measurement result is lower than the actual temperature due to the low-temperature liquid entering from the liquid inlet. A much lower situation is avoided and the temperature measurement results are always accurate. As a result, the amount of high-frequency power supplied is always an appropriate amount based on accurate temperature measurement results, so that the heating temperature of high-frequency dielectric heating and Joule heat can be accurately controlled, and the heating temperature is always kept at an appropriate temperature. Kept.
Further, 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, by supplying high-frequency power with a supply amount corresponding to the temperature measurement result of the temperature sensor by the power supply means, the heating temperature of the high-frequency dielectric heating and Joule heat can be accurately controlled.
Furthermore, during heating by high-frequency dielectric heating and Joule heating, when the liquid in the balloon that is in an inflated state by introducing the liquid is moved in and out between the catheter and the balloon by the liquid stirring means, the liquid in the balloon is stirred. Liquids with different temperatures mix and the temperature of the liquid in the balloon becomes uniform, and uneven heating due to high frequency dielectric heating and Joule heat can be suppressed. Further, although the low temperature liquid enters and exits the balloon from the liquid introduction port as the liquid is stirred by the liquid stirring means, the temperature sensor is located away from the liquid introduction port as described above. The temperature measurement of the temperature sensor is not hindered by the entry and exit of the liquid.

  According to a second aspect of the present invention, in the ablation catheter with a balloon according to the first aspect, the temperature sensor is positioned in the vicinity of the central axis of the balloon that virtually connects the balloon front end and the balloon rear end.

  According to the invention of claim 2, when the balloon is inflated, the balloon is expanded with the balloon central axis virtually connecting the balloon tip and the balloon rear end, and conversely when the balloon is deflated Since the balloon is deflated with the balloon central axis as the end point, when the temperature sensor is in the vicinity of the balloon central axis, the balloon can be smoothly inflated or deflated without the membrane being caught by the temperature sensor. Further, the temperature sensor does not come into contact with the balloon when the balloon is inflated, and damage to the balloon can be prevented.

  Further, the invention of claim 3 is the ablation catheter with a balloon according to claim 1 or 2, wherein the power transmission for supplying high-frequency power to the sensor lead wire for extracting a temperature measurement signal from the temperature sensor and the high-frequency energization inner electrode. All of the supply leads are passed through the catheter with an electrically insulating protective coating.

  (Operation / Effect) According to the invention of claim 3, 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 high frequency energizing inner electrode 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 fourth aspect of the present invention, in the ablation catheter with a balloon according to the third 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 4, 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 fifth aspect of the present invention, in the ablation catheter with a balloon according to the third 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 5, the electrical insulation 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 insulation of the electrical insulation protective coating is increased. In addition, heat generation of the catheter due to leakage / invasion is sufficiently suppressed.

  The invention of claim 6 is the ablation catheter with a balloon according to any one of claims 1 to 5, wherein a forced cooling mechanism for the catheter is not provided.

  (Operation / Effect) According to the invention of claim 6, 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 7 is the ablation catheter with a balloon according to any one of claims 1 to 6, wherein the catheter is a double tube in which the outer tube shaft and the inner tube shaft are concentrically threaded so as to be axially movable. This is a cylindrical catheter, in which the tip of the balloon is fixed to the tip of the inner cylinder shaft, and the rear end of the balloon is fixed to the tip of the outer cylinder shaft.

  (Operation / Effect) According to the invention of claim 7, the shape of the balloon can be variously changed by moving the outer cylinder shaft or the inner cylinder shaft in the axial direction.

  According to an eighth aspect of the present invention, in the ablation catheter with a balloon according to the seventh aspect, the inner electrode for high-frequency energization is shaped into a coil that winds around the outer periphery of the inner cylindrical shaft without restricting the inner cylindrical shaft. In addition to the high frequency energization inner electrode being fixed to the outer cylinder shaft side, the temperature sensor is fixed to the high frequency energization inner electrode.

  (Operation / Effect) According to the invention of claim 8, since the high-frequency energization inner electrode is shaped into a coil, the high-frequency energization inner electrode is made of the inner cylindrical shaft in addition to the efficient supply of high-frequency power. Since the outer periphery is arranged so as not to constrain the inner cylinder shaft, it is possible to prevent the inner electrode for high-frequency energization from causing the movement of the inner cylinder shaft in the axial direction and causing film damage to the balloon. . Further, an inner electrode for high-frequency energization is fixed to an outer cylindrical shaft to which a rear end portion of the balloon is fixed, and a temperature sensor is fixed to the inner electrode for high-frequency energization. Since the distance between the two is always constant, it is easy to arrange the temperature sensor to be located between the balloon center and the balloon tip.

  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 inflated 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 a ring of the pulmonary vein mouth. In the case of the peripheral portion, since the balloon can be brought into close contact with the pulmonary vein mouth by slightly inserting the tip of the balloon into the pulmonary vein mouth, the entire annular peripheral portion of the pulmonary vein mouth can be reliably cauterized. In addition, since the balloon can be prevented from entering the pulmonary vein, the inside of the pulmonary vein can be cauterized to prevent stenosis.

  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.

  As described above, according to the ablation catheter with a balloon according to the first aspect of the present invention, a temperature sensor that detects a heating temperature while heating a target lesion site to be ablated by high-frequency dielectric heating and Joule heat. In a balloon inflated by the introduction of liquid, it is always located between the center of the balloon and the tip of the balloon and away from the liquid inlet at the rear end of the balloon. Even when a low-temperature liquid comes in from the liquid inlet at the rear end of the balloon during heating by the low-temperature liquid, it is difficult for the low-temperature liquid to touch the temperature sensor directly. Since the situation where the temperature result is much lower than the actual temperature is avoided and the temperature measurement result is always accurate, the supply amount of high-frequency power is always based on the accurate temperature measurement result. Becomes Seiryo, warming the temperature of the high-frequency dielectric heating and Joule heating is kept at all times suitable temperature is accurately controlled.

  Hereinafter, embodiments of the ablation catheter with a balloon of 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 an ablation catheter 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 catheter in which an outer tube shaft 3 and an inner tube shaft 4 are concentrically connected to each other so as to be axially movable, 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 catheter 1 having a double cylinder type, the shape of the balloon 2 can be variously changed by moving the outer cylinder shaft 3 or the inner cylinder 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 outer shape with a tapered shape, the balloon can be prevented from entering the pulmonary vein, and the balloon is tightly inserted into the pulmonary vein mouth by inserting the tip of the balloon into the pulmonary vein mouth a little. Since they are brought into close contact with each other, the entire annular peripheral edge of the pulmonary vein opening can be surely cauterized. As the material of the balloon 2, a stretchable material excellent in antithrombogenicity is used. Polyurethane-based 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.

  Further, in the case of the ablation catheter of the embodiment, an internal electrode for high-frequency energization (hereinafter abbreviated as “inner electrode” as appropriate) 5 is installed in the balloon 2, and the liquid is introduced 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 inner electrode 5 is formed into a coil that wraps around the outer periphery of the inner cylindrical shaft 4 in such a manner that the inner cylindrical shaft 4 is slightly constrained so that the inner electrode 5 is not restrained by the inner electrode 5. It is fixed to the tube shaft 3 side.

  Examples of the material of the inner electrode 5 include high conductivity metal wires such as copper and silver. 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 inner 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. When high-frequency energization is performed between the inner electrode 5 and the outer electrode 7, heating by high-frequency dielectric heating and Joule heat is performed. The appropriate temperature for tissue cauterization during heating by high-frequency dielectric heating and Joule heating is usually in the range of 50 ° C to 70 ° C.

  The liquid feeding device 6 includes 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. It is fed into the balloon 2 from the introduction port 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.

  Further, in the case of the ablation catheter of the embodiment, a diaphragm type stirring mechanism (liquid) that stirs the liquid in the balloon 2 by moving the balloon 2 in and out of the balloon 2 through the catheter 1 by injecting the 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, the temperature sensor 9 that is always positioned between the center of the balloon and the tip of the balloon in the balloon 2 that is inflated by the liquid feeding by the liquid feeding device 6, and the temperature measurement of the temperature sensor 9. A high-frequency power supply (power supply means) 10 that supplies high-frequency power in a supply amount according to the result. The frequency of the high-frequency power ranges from several MHz to several hundred MHz, and is usually around 10 MHz. During the 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.

  On the other hand, during the heating by high frequency dielectric heating and Joule heating, the temperature sensor 9 is always positioned between the center of the balloon (half the length d in FIG. 3) and the balloon tip in the inflated balloon 2. In this case, since it is away from the liquid inlet 2A at the rear end of the balloon, the low temperature liquid newly entered from the liquid inlet 2A at the rear end of the balloon during the heating by high frequency dielectric heating and Joule heat is detected by the temperature sensor. The temperature measurement result of the temperature sensor 9 is much lower than the actual temperature by the low-temperature liquid that has entered from the liquid inlet 2A, and the temperature measurement result is always accurate. Therefore, the high-frequency power supply 10 always supplies high-frequency power in an appropriate amount based on an accurate temperature measurement result, so that the heating temperature of the high-frequency dielectric heating and Joule heat is accurately controlled and always kept at an appropriate temperature.

  That is, a low temperature liquid enters and exits between the balloon 2 and the catheter 1 as the liquid is stirred by the liquid stirring mechanism 8, but the temperature sensor 9 is located away from the liquid inlet 2A as described above. Therefore, the temperature measurement of the temperature sensor 9 is not hindered by the entry and exit of the low temperature liquid accompanying the stirring of the liquid. 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.

  The temperature sensor 9 is fixed to the inner electrode 5 for high-frequency energization. As described above, the inner electrode 5 is fixed to the outer cylinder shaft 3 to which the rear end portion of the balloon 2 is fixed, the temperature sensor 9 is fixed to the inner electrode 5, and the rear end portion of the balloon 2 is fixed. Since the distance between the temperature sensor 9 and the temperature sensor 9 is always constant, it is very easy to determine the arrangement in which the temperature sensor 9 is located between the balloon center and the balloon tip. Further, since the inner electrode 5 is arranged so as not to constrain the inner cylinder shaft 4, it is possible to avoid the inner electrode 5 from causing the movement of the inner cylinder shaft 4 in the axial direction and causing damage to the balloon 2.

  In addition, the temperature sensor 9 fixed to the inner electrode 5 is positioned in the vicinity of the balloon center axis 2a that virtually connects the balloon front end and the balloon rear end. Since the inner electrode 5 wound around the inner cylindrical shaft 4 in which the balloon central axis 2a and the cylindrical axis substantially coincide with each other is located in the vicinity of the balloon central axis 2a, the temperature sensor 9 fixed to the inner electrode 5 is naturally , Located in the vicinity of the balloon central axis 2a. When the balloon 2 is inflated, the balloon 2 is expanded with the balloon center axis 2a as a starting point. Conversely, when the balloon 2 is deflated, the balloon 2 is deflated with the balloon center axis 2a as an end point. When in the vicinity of the central axis 2a, the balloon 2 can be smoothly expanded and contracted without the membrane being caught by the temperature sensor 9. Further, the balloon is not contacted when the balloon is inflated, and the balloon can be prevented from being damaged.

  Further, as shown in FIG. 4, the sensor lead wire 11 for taking out a temperature measurement signal from the temperature sensor 9 and the power supply lead wire 12 for supplying high frequency power to the high frequency energizing inner electrode are both electrically insulating protective coatings. 13 and 14 are passed through the clearance between the outer tube shaft 3 and the inner tube shaft 4 of the catheter 1. 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 for the sensor lead wire 11 and the power supply lead wire 12 include copper, silver, platinum, tungsten, and alloys. 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. This further suppresses heat generation of the outer cylindrical shaft 3 and the inner cylindrical shaft 4 due to leakage and intrusion of high-frequency power. 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.

  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 can be given.

  Further, radiation shielding metal pipes 3A and 4A are attached to the front ends of the outer cylinder shaft 3 and the inner cylinder shaft 4, and the front end portion and the rear end portion of the balloon 2 are attached to the metal pipes 3A and 4A. The 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 is pushed by the catheter 1 along the catheter 1 and reaches the left atrium from the inferior vena cava, and then the inflated balloon 2 is placed in close contact with the pulmonary vein opening Qa so that the inner electrode 5 and the outer electrode 7 are in close contact with each other. During this period, high-frequency energization is performed to cauterize the annular peripheral edge of the pulmonary vein opening Qa.

  Next, specific examples 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.

  Further, the tip portion of a 0.5 mm diameter electric annealed copper wire having a silver plating of 0.1 μm as the inner electrode 5 is shaped into a coil shape having an inner diameter of 1.6 mm and a length of 10 mm, and the power feeding lead wire 4 is 4 A copper wire having a length of 1 m to which an electrically insulating protective coating 14 was applied was connected using a fluorinated ethylene-6 fluorinated propylene copolymer (FEP). 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 inner electrode 5, the inner electrode 5 is inserted 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. When the temperature sensor 9 and the inner electrode 5 are fixed, the temperature sensor 9 is positioned approximately in the middle between the balloon center and the balloon tip (that is, 10 mm from the balloon tip toward the center), that is, positioned away from the liquid inlet 2A. I made it. 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] Next, a comparative example will be described. That is, when the temperature sensor 9 and the inner electrode 5 are fixed, the temperature sensor 9 is positioned slightly closer to the rear end from the center of the balloon center and the rear end of the balloon (that is, closer to the center by 5 mm from the balloon rear end). An ablation catheter of a comparative example was produced in the same manner as in the example except that it was fixed in an arrangement close to the liquid inlet 2A.

  [Heating test] Next, high-frequency dielectric heating and Joule heat were used to conduct heating test tests on the fabricated ablation catheters of Examples and Comparative Examples, respectively, by applying high-frequency energization. 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 inner 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. And while supplying the high frequency power, the intensity of the temperature measurement signal of the temperature sensor 9 was continuously recorded by the recorder. From the recording of the recorder, after the initial fluctuation period, the temperature obtained from the intensity of the temperature measurement signal of the temperature sensor 9 was always 70 ° C. ± about 1 ° C., and the temperature inside the balloon could be measured accurately. Therefore, since there was no local temperature measurement fluctuation around the temperature sensor 9, an excessive or insufficient electric power was not supplied from the high frequency power supply 10, and a stable output could be maintained. At the same time, the accurate maintenance time of the set temperature could be measured.

  Next, the test was performed on the comparative ablation catheter in the same manner as in the example. From the recording of the recorder, after the initial fluctuation period has passed, local temperature measurement fluctuations have occurred around the temperature sensor 9, so that the temperature is often outside the appropriate temperature range to 70 ° C. ± about 4 ° C., and the temperature inside the balloon is accurately measured. I couldn't warm it. Therefore, the power supply from the high frequency power supply 10 is not stable, and at the same time, the accurate maintenance time of the set temperature cannot be measured.

  Therefore, as in the ablation catheter of the embodiment, the temperature sensor 9 is always in a position near the tip between the balloon center and the tip of the balloon 2 in the inflated state, and the liquid inlet 2A at the rear end of the balloon. If the temperature sensor 9 is far from the temperature sensor 9, it is difficult for the temperature sensor 9 to directly touch the low-temperature liquid newly entering from the liquid inlet 2 </ b> A during heating by high-frequency dielectric heating and Joule heat, and the temperature sensor 9 is low-temperature. Since the situation in which the temperature measurement result is much lower than the actual temperature is avoided by directly touching the liquid, the temperature measurement result is always accurate, and as a result, the high-frequency power supply 10 has an appropriate supply amount according to the accurate temperature measurement result. It was proved that the high-frequency dielectric heating and Joule heating temperature were accurately controlled and always kept at an appropriate temperature.

  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 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 2 ... Balloon 2A ... Liquid introduction port 2a ... Balloon center axis | shaft 3 ... Outer cylinder shaft 4 ... Inner cylinder shaft 5 ... Inner electrode for high frequency electricity supply 6 ... Liquid delivery apparatus (liquid delivery means)
7 ... outer electrode for high frequency energization 8 ... Diaphragm type stirring mechanism (liquid stirring means)
9 ... Temperature sensor 10 ... High frequency power supply (electric 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 (10)

An inflatable / deflatable balloon disposed at the distal end of the catheter and having a liquid inlet at the rear end of the balloon;
An inner electrode for high-frequency energization installed in the balloon;
A temperature sensor that is always located between the center of the balloon and the tip of the balloon in the balloon in an inflated state by introducing liquid from the liquid inlet;
A liquid feeding means for feeding the liquid into the balloon from the liquid inlet through the catheter;
Power supply means for supplying high-frequency power in a supply amount corresponding to the temperature measurement result of the temperature sensor;
Liquid agitation means for agitating the liquid in the balloon by allowing the liquid in the balloon in an inflated state 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 characterized by the above.   The ablation catheter with a balloon according to claim 1, wherein the temperature sensor is located in the vicinity of the central axis of the balloon that virtually connects the balloon front end and the balloon rear end.   The ablation catheter with a balloon according to claim 1 or 2, wherein both a sensor lead wire for taking a temperature measurement signal from a temperature sensor and a power feeding lead wire for feeding high frequency power to the high frequency energizing inner electrode are provided. An ablation catheter with a balloon that is passed through the catheter with an electrically insulating protective coating.   The ablation catheter with a balloon according to claim 3, 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 3, 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 5, 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 6, wherein the catheter is a double tube catheter in which an outer tube shaft and an inner tube shaft are concentrically connected to each other so as to be axially movable. An ablation catheter with a balloon in which a distal end portion is fixed to a distal end of an inner cylindrical shaft and a rear end portion of a balloon is fixed to a distal end of an outer cylindrical shaft.   The ablation catheter with a balloon according to claim 7, wherein the high frequency energizing inner electrode is shaped into a coil that winds around the outer periphery of the inner cylindrical shaft without restricting the inner cylindrical shaft, and the high frequency energizing inner electrode is the outer cylindrical shaft. In addition to being fixed to the side, an ablation catheter with a balloon in which a temperature sensor is fixed to an inner electrode for high-frequency energization.   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. The ablation catheter with a balloon according to claim 1, wherein the liquid fed by the liquid feeding means passes through a clearance between the outer cylinder shaft and the inner cylinder shaft.

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