JP2011098211A - Puncture needle for ablation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a puncture needle for cauterization which does not cause thermal damage to a normal tissue and a body surface in the vicinity of a part other than the tip end part and can securely cauterize lesion tissue in the vicinity of the tip end with lower energy than a conventionally well-known thing. <P>SOLUTION: The puncture needle for cauterization includes: an acute tip end electrode 60, a high frequency current being energized between the electrode and a counter electrode plate; and a hard electrical insulation capillary 70 which is connected to the proximal end side of the tip end electrode 60 and has rigidity necessary for the puncture needle for cauterization. The tip end electrode 60 comprises an acute tip end part 61 and a falling-proof flange part 62. The outer surface of the flange part 62 is covered with the tip end part of the electrical insulation capillary 70. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a puncture needle for ablation, and more particularly to a puncture needle used for high-frequency ablation therapy.

  Recently, radiofrequency ablation therapy has been performed as a method for locally treating a lesion site such as liver cancer. Patent Documents 1 and 2 disclose a collective electrode system and an electrode device used for radiofrequency ablation therapy. Has been.

Non-Patent Document 1 introduces radio frequency ablation therapy, which is a high-frequency ablation therapy. This radiofrequency ablation therapy is a treatment method in which a radiofrequency current, which is a type of high frequency, is passed from a puncture needle to the human body to cauterize a lesion tissue such as a malignant neoplasm to coagulate and necrotize.
When performing radiofrequency ablation therapy, a system including a radio wave generator, a puncture needle that constitutes an electrode, and a counter electrode is usually used.

  Thus, the radio wave generator and the puncture needle are electrically connected, and the system is set up by electrically connecting the counter electrode plate and the radio wave generator attached to the vicinity of the patient's thigh, When energization is started after the puncture needle is punctured into the lesion, Joule heat is generated in the living tissue by the radio wave current flowing between the puncture needle and the counter electrode.

  Here, the heat generation part due to the radio wave current is not a puncture needle but a living tissue in the current path. However, since the current density is high in the vicinity of the puncture needle, the tissue near the puncture needle (lesion) and the puncture needle itself are The lesion becomes the highest temperature and the lesion in the vicinity of the puncture needle is coagulated and necrotic.

  In the radiofrequency ablation therapy as described above, the maximum radiowave output is, for example, 200 W. Moreover, the puncture needle which comprises an electrode consists of metal thin tubes, such as stainless steel, The length is about 200 mm normally.

Special table 2001-510702 Special table 2006-513830 Goku Okita and Masao Ogura, “Radio-wave ablation therapy for liver cancer” (Medical School), June 15, 2001

  Since a conventional ablation puncture needle is made of a thin metal tube, when a high-frequency current is applied to such a puncture needle, the puncture needle becomes hot throughout its entire length (about 200 mm). For this reason, when energized in a state where the distal end portion of the puncture needle is punctured in the lesioned part, normal tissue near the puncture needle other than the distal end portion is damaged or destroyed, or the body surface that contacts the proximal end portion of the puncture needle Or burns.

  Further, the conventional ablation puncture needle is entirely energized, and therefore requires excessive high frequency energy.

  For the above problems, it is also conceivable to cover the surface of the puncture needle other than the tip portion with an insulating material.

  However, due to the high thermal conductivity of the core material (metal thin tube), the heat of the tip portion is conducted to the base end portion, and the insulation coating layer having a sufficient thickness on the surface of the core material (metal thin tube) Insulation breakdown is likely to occur. Thus, the above-mentioned problem cannot be solved only by insulatingly covering the surface of the puncture needle other than the tip portion.

  The present invention has been made based on the above situation. It is an object of the present invention to prevent the thermal damage to tissues (normal tissue and body surface) in the vicinity of a portion other than the tip portion, and in the vicinity of the tip portion with lower energy than conventionally known ablation puncture needles. An object of the present invention is to provide a puncture needle for cauterization that can surely cauterize a tissue (lesioned portion) in the body.

The ablation puncture needle of the present invention is a hard tip having a rigidity necessary for a sharp tip electrode to which a high-frequency current is passed between a counter electrode plate and a proximal end side of the tip electrode. An electrically insulating thin tube, and the tip electrode has a sharp tip and a flange portion for preventing dropping, and an outer surface of the flange portion is formed by a tip portion of the electrically insulating thin tube. It is characterized by being covered.

In the ablation puncture needle according to the present invention , the electrically insulating thin tube is preferably made of a resin. Further, it is preferable that the tip electrode and the electrically insulating thin tube (resin tube) are integrally formed by insert molding.

  In the ablation puncture needle of the present invention, it is preferable that cooling means for cooling the tip electrode is provided by flowing water through the tip electrode.

(1) According to the ablation puncture needle of the present invention, the tissue (normal tissue / body surface) in the vicinity of the portion other than the tip portion is not thermally damaged, and compared with a conventionally known ablation puncture needle. With low energy, the tissue (lesioned part) in the vicinity of the tip can be surely cauterized.

( 2 ) Since the puncture needle for cauterization according to the present invention is composed of an electrically insulating thin tube other than the tip portion (tip electrode), a high-frequency current is not passed through the electrically insulating capillary tube. Absent. In addition, since the material constituting the electrically insulating capillary is usually lower in thermal conductivity than metal, the electrically insulating capillary is not heated by the heat generated at the tip electrode. Therefore, according to the ablation puncture needle of the present invention , the tissue (normal tissue / body surface) in the vicinity of the portion (electrically insulating thin tube) other than the tip portion is not thermally damaged.

Further, since the high-frequency current is applied only to the tip electrode, the tissue (lesioned portion) in the vicinity of the tip electrode is intensively cauterized with lower energy than a conventionally known cauterization puncture needle in which the whole is an energized region. be able to.
Furthermore, since the outer surface of the flange portion of the tip electrode is covered with the tip portion of the electrically insulating thin tube, the tip electrode and the electrically insulating thin tube are connected, so that both are firmly bonded and used for cauterization. It is possible to reliably prevent the tip electrode from falling off when the puncture needle is used.

It is sectional drawing which shows the form used as a reference in order to demonstrate the ablation puncture needle of this invention. It is the schematic which shows typically the whole structure of the radiofrequency ablation therapy system provided with the puncture needle for ablation shown in FIG. It is sectional drawing which shows one Embodiment of the puncture needle for ablation of this invention.

< Reference form >
FIG. 1 is a cross-sectional view showing a form (a cauterization puncture needle different from the present invention) which serves as a reference for explaining the cauterization puncture needle of the present invention .
The ablation puncture needle 1 of the present embodiment is a sharp tip electrode 10 through which a high-frequency current is passed, an electrically insulating connecting tube 20 connected to the proximal end thereof, and a metal connected to the proximal end thereof. It consists of a thin tube 30. The cautery puncture needle 1 is held by a gripping portion 40 on the proximal end side of the metal thin tube 30.
The length L0 of the cauterizing puncture needle 1 protruding from the tip of the gripping portion 40 is usually 150 to 500 mm, preferably about 200 mm, and has an outer diameter (outside of the electrically insulating connecting tube 20 and the metal thin tube 30). (Diameter) is about 0.8 to 3.0 mm.

  The tip electrode 10 constituting the ablation puncture needle 1 is made of metal and is constituted by a sharp tip portion 11 and a flange portion 12, and the length L1 of the tip portion 11 in the tip electrode 10 is usually 10 to 50 mm. The thickness is preferably 20 to 30 mm.

  When this length L1 is too short, the range which can be treated by one cauterization (puncture) becomes narrow. On the other hand, if the length L1 is too long, the object of the present invention cannot be achieved. That is, when the lesioned part is punctured by the distal electrode, the proximal end part of the distal electrode may come into contact with the normal tissue, and the normal tissue may be thermally damaged during cauterization.

  As the metal constituting the tip electrode 10, all conventionally known metals as the metal constituting the ablation puncture needle can be used, and examples thereof include stainless steel.

  The electrically insulating connecting pipe 20 constituting the cauterizing puncture needle 1 is made of an electrically insulating material, and its length L2 is 0.5 to 50 mm, preferably 2 to 20 mm.

  The electrically insulating connecting pipe 20 is required to have electrical insulating properties, heat insulating properties, rigidity (being hard), and heat resistance against ablation temperature. The electrically insulating material constituting the electrically insulating connecting pipe 20 is not particularly limited as long as it has the above-mentioned characteristics. However, a resin material and a ceramic material are preferable, and the electrically insulating and heat insulating properties are preferable. It is particularly preferable to use a resin material because it is easy to mold.

  The resin constituting the electrically insulating connecting pipe 20 may be a thermoplastic resin or a thermosetting resin. The resin includes ebonite. Specifically, cyclic olefin resin, polyphenylene sulfide, polyether ether ketone, polybutylene terephthalate, polycarbonate, polyamide, polyacetal, modified polyphenylene ether, polyester resin, polytetrafluoroethylene, fluorine resin, polysulfone, polyetherimide , Polyethersulfone, polyetherketone, polyetherlactone, liquid crystal polyester, polyamideimide, polyimide, polyethernitrile, polypropylene, polyethylene; epoxy resin, unsaturated polyester resin, phenol resin, urea resin, melamine resin, polyurethane resin be able to. Of these, polycarbonate, polyamide and polyacetal are preferred.

The metal thin tube 30 constituting the cauterizing puncture needle 1 is formed of a tubular member having an inner hole communicating with the electrically insulating connecting tube 20, and a flange portion 32 is formed at the tip thereof.
The length L3 (L0-L1-L2) excluding the flange portion 32 of the metal thin tube 30 protruding from the tip of the grip portion 40 is 50 to 489.5 mm, and preferably 150 to 178 mm. The metal thin tube 30 is required to have rigidity (particularly bending rigidity) and elasticity (particularly bending elasticity) required for a normal ablation puncture needle.
As the metal constituting the metal thin tube 30, all conventionally known metals constituting the cauterization puncture needle can be used, and examples thereof include stainless steel. The grip portion 40 that holds the proximal end side of the metal thin tube 30 is made of resin, rubber, elastomer, or the like.

As shown in FIG. 1, the tip portion of the electrically insulating connecting pipe 20 is formed so as to cover the outer surface of the flange portion 12 of the tip electrode 10. As a result, a sufficient bonding area between the tip electrode 10 and the electrically insulating connecting pipe 20 can be ensured, and the two can be firmly coupled and separated by a drop-off preventing effect (anchor effect) due to the flange shape. There is nothing. As a result, during an operation with the puncture needle 1 of the present embodiment , for example, when the puncture needle 1 is removed, an accident in which the tip electrode 10 is dropped from the electrically insulating connecting tube 20 and is left in the body is ensured. Can be prevented.

  Further, the proximal end portion of the electrically insulating connecting pipe 20 is formed so as to cover the outer surface of the flange portion 32 of the metal thin tube 30. As a result, a sufficient adhesion area between the metal thin tube 30 and the electrically insulating connecting tube 20 can be secured, and the two are not firmly separated due to the drop-off preventing effect due to the flange shape. .

  Connected to the tip electrode 10 is a tip portion of a lead wire 51 for supplying a high-frequency current. The lead wire 51 extends to the inner hole of the puncture needle 1 (the electrically insulating connecting tube 20 and the metal thin tube 30) and extends from the proximal end of the metal thin tube 30 to the inner hole of the gripping portion 40. It extends through the inner hole of the gripping part 40 and penetrates the proximal end wall 41 of the gripping part 40. The proximal end portion of the lead wire 51 is connected to a high-frequency current output portion of a radio wave generator (not shown).

  In addition, the tip portion (thermocouple) of a thermocouple cable 52 is connected to the tip electrode 10. The thermocouple cable 52 extends to the inner hole of the puncture needle 1, extends from the proximal end of the metal thin tube 30 to the inner hole of the holding part 40, and further extends to the inner hole of the holding part 40 and holds it. It penetrates the base end wall 41 of the portion 40. A proximal end portion of the thermocouple cable 52 is connected to a temperature sensor input portion of a radio wave generator (not shown). Thereby, the output current to the tip electrode 10 can be controlled while monitoring the temperature of the tip electrode 10. Instead of the thermocouple cable 52, a thermistor cable provided with a thermistor at the tip may be used as the temperature sensor for the tip electrode 10.

Moreover, the tip of the water supply tube 53 for supplying cooling water to the inside is inserted into the tip electrode 10. The water supply tube 53 extends to the inner hole of the puncture needle 1, extends from the proximal end of the metal thin tube 30 to the inner hole of the grip portion 40, and further extends to the inner hole of the grip portion 40 to hold the grip portion 40 base end walls 41 are penetrated. The proximal end of the water supply tube 53 is connected to a cooling water supply source (not shown).
The cooling water supplied from the distal end opening of the water supply tube 53 cools the distal end electrode 10 from the inside, and then penetrates the proximal end wall 41 through the inner hole of the puncture needle 1 and the inner hole of the grasping portion 40 (gripping The drainage tube 54 is formed so as to communicate the inner hole of the portion 40 and the outside.

  Thus, by providing the cooling means for the tip electrode 10 by circulating water inside the tip electrode 10, when the high-frequency current is supplied to the tip electrode 10, accompanying the excessive temperature rise of the tip electrode 10, It is possible to suppress an increase in impedance caused by moisture evaporation and tissue carbonization in the tissue around the electrode. In addition, since the tip electrode 10 can be rapidly cooled after energization of the high-frequency current, damage to the electrode peripheral tissue due to residual heat (heat remaining in the electrode) can be prevented.

The material of the water supply tube 53 and the drainage tube 54 constituting the cooling means is not particularly limited, and may be a metal tube or a resin tube.
Moreover, it is good also as a structure which inserts the front-end | tip of the tube of a double tube structure in the front-end | tip electrode 10, supplies cooling water from the inner tube, and discharges the water after cooling from an outer tube (jacket).

FIG. 2 is a schematic view schematically showing the overall configuration of a system (radio wave ablation therapy system) including the ablation puncture needle 1 of the present embodiment . This system includes a puncture needle 1 according to this embodiment , a radio wave generator 2, a counter electrode plate 3, a cooling water supply source 4, and a drainage storage tank 5.

As shown in FIG. 2, puncture needle 1 and radio wave generator 2 are connected by lead wire 51. The puncture needle 1 and the cooling water supply source 4 are connected by a water supply tube 53. Further, the puncture needle 1 and the drainage storage tank 5 are connected by a drainage tube 54.
The counter electrode plate 3 is affixed near the thigh of the patient 100, and the counter electrode plate 3 and the radio wave generator 2 are connected by a lead wire 55.

  After setting up the system as shown in FIG. 2, the tip electrode 10 of the puncture needle 1 is punctured into a lesioned part of the patient 100 while monitoring an ultrasound image. At this time, normal tissue is present around the portion of the puncture needle 1 other than the distal electrode 10 (the electrically insulating connecting tube 20 and the metal thin tube 30), and the proximal end portion of the puncture needle 1 is the body surface of the patient 100. Will be in contact with.

  When energization is started in this state, the radio wave current from the radio wave generator 2 flows through the body of the patient 100 via the lead wire 51 and the puncture needle 1 and is attached to the vicinity of the thigh of the patient 100. It returns to the radio wave generator 2 via the counter electrode plate 3 and the lead wire 55. Then, Joule heat is generated in the living tissue by the radio wave current flowing between the puncture needle 1 and the counter electrode plate 3. Here, the frequency of the radio wave is, for example, 300 kHz to 6 MHz, and the maximum output of the radio wave current is, for example, 200 W.

  The amount of Joule heat generated by the radio wave current is the largest in the tissue near the tip electrode 10 having a high current density, that is, in the lesioned part of the patient 100, whereby the lesioned part becomes high in temperature and cauterized. Leads to coagulation and necrosis. At this time, the tip electrode 10 located at the center of the lesioned part that is cauterized has the same temperature as that of the lesioned part, so the temperature of the tip electrode 10 is monitored by the thermocouple cable (52) shown in FIG. Thus, the cauterization temperature in the lesion can be grasped.

  Here, the shochu temperature is usually 50 to 90 ° C., preferably 55 to 70 ° C. If the ablation temperature is too low, the diseased tissue cannot be reliably coagulated / necrotic. On the other hand, if the ablation temperature is too high, the dry state or carbonization of the tissue occurs due to rapid boiling of water, and the impedance rises and current does not flow easily. As a result, the diseased tissue cannot be coagulated.

  When it is determined that the temperature of the monitored tip electrode 10 has become too high during energization, the flow of the radio wave current from the radio wave generator 2 is suppressed or stopped, and the cooling supplied from the supply source 4 By increasing the amount of water, the temperature of the tip electrode 10 and, consequently, the temperature of the tissue in the vicinity of the tip electrode 10 are reduced, thereby suppressing an increase in impedance.

  When the intended lesioned cautery is completed, energization is stopped, the amount of cooling water supplied from the supply source 4 is increased, and the tip electrode 10 and the nearby tissue are rapidly cooled. Thereby, it is possible to prevent damage to surrounding tissues due to residual heat (heat remaining in the tip electrode 10).

  If the lesion is large, after cauterization for a certain period of time, the tip electrode 10 of the puncture needle 1 is pulled out from the portion coagulated by cauterization and applied to a portion that has not coagulated (lesion that does not have a therapeutic effect due to cauterization). Puncture again after changing the position, and perform additional cauterization under the same conditions.

In the puncture needle 1 of the present embodiment , the metal thin tube 30 constituting the proximal end portion thereof is electrically insulated from the distal electrode 10 by the electrically insulating connecting tube 20. Thus, the radio wave current from the radio wave generator 2 is not energized.
Further, since the material (resin) constituting the electrically insulating connecting tube 20 has a remarkably lower thermal conductivity than that of metal, the heat generated in the tip electrode 10 is transmitted through the electrically insulating connecting tube 20 and is a metal thin tube. 30 is not heated to a high temperature.
Therefore, according to the puncture needle 1 of the present embodiment , the normal tissue existing around the portion other than the distal electrode 10 (the electrically insulating connecting tube 20 and the metal thin tube 30) and the proximal end portion of the puncture needle 1 ( There is no thermal damage to the body surface of the patient 100 in contact with the metal capillaries 30).

  Moreover, since the radio wave current from the radio wave generator 2 is applied only to the tip electrode 10, the tip electrode 10 was punctured with high-frequency energy lower than that of a conventionally known cauterization puncture needle that is the entire energization region. The lesion can be intensively cauterized.

< Embodiment >
FIG. 3 is a cross-sectional view showing an embodiment of the ablation puncture needle of the present invention. In the figure, the same reference numerals are used for the same or corresponding components as in the reference embodiment .

The ablation puncture needle 6 of this embodiment includes a sharp tip electrode 60 through which a high-frequency current is passed, and an electrically insulating thin tube 70 connected to the base end side thereof. The cautery puncture needle 6 is held by the gripping portion 40 on the proximal end side of the electrically insulating thin tube 70.
The length L5 of the ablation puncture needle 6 protruding from the tip of the gripping part 40 and the outer diameter of the ablation puncture needle 6 are the length L0 of the ablation puncture needle 1 and the outer diameter of the ablation puncture needle 1 according to the reference embodiment. It is the same.

  The tip electrode 60 constituting the ablation puncture needle 6 is made of metal and is constituted by a sharp tip portion 61 and a flange portion 62. The length L6 of the tip portion 61 of the tip electrode 60 is usually 20 to 50 mm. The thickness is preferably 20 to 30 mm.

  When this length L6 is too short, the range which can be treated by one cauterization (puncture) becomes narrow. On the other hand, if the length L6 is too long, the object of the present invention cannot be achieved. That is, when the lesioned part is punctured with the distal electrode, the proximal end of the distal electrode may come into contact with the normal tissue, and the normal tissue may be thermally damaged during cauterization.

  As the metal constituting the tip electrode 60, any conventionally known metal constituting the ablation puncture needle can be used, and examples thereof include stainless steel.

  The electrically insulating thin tube 70 constituting the cauterizing puncture needle 6 is made of a tubular member made of an electrically insulating material, and has a length L7 (L5-L6) of the electrically insulating thin tube 70 protruding from the tip of the grip portion 40. ) Is 150 to 180 mm, preferably 170 to 180 mm.

  The electrically insulating thin tube 70 is required to have electrical insulation properties, heat insulation properties, heat resistance against ablation temperature, and rigidity (particularly bending rigidity) and elasticity (particularly bending elasticity) required for a normal ablation puncture needle. Is required.

  The electrically insulating material constituting the electrically insulating thin tube 70 is not particularly limited as long as it has the above-described characteristics. However, a resin material and a ceramic material are preferable, and the electrically insulating and heat insulating properties are excellent. It is particularly preferable to use a resin material because it is good and easy to mold.

The resin constituting the electrically insulating thin tube 70 may be a thermoplastic resin or a thermosetting resin. Specifically, the resin illustrated as what comprises the electrically insulating connecting pipe 20 which concerns on a reference form can be mentioned.

  The tip electrode 60 is connected to the tip of a lead wire 51 for supplying a high-frequency current. The lead wire 51 extends to the inner hole of the puncture needle 6, extends from the proximal end of the electrically insulating capillary 70 to the inner hole of the gripping part 40, and further extends to the inner hole of the gripping part 40 and grips it. It penetrates the base end wall 41 of the portion 40. The proximal end portion of the lead wire 51 is connected to a high-frequency current output portion of a radio wave generator (not shown).

  Further, the tip portion (thermocouple) of the thermocouple cable 52 is connected to the tip electrode 60. The thermocouple cable 52 extends to the inner hole of the puncture needle 6, extends from the proximal end of the electrically insulating capillary 70 to the inner hole of the gripping part 40, and further extends to the inner hole of the gripping part 40. It penetrates the base end wall 41 of the grip portion 40. A proximal end portion of the thermocouple cable 52 is connected to a temperature sensor input portion of a radio wave generator (not shown). A thermistor cable may be used as the temperature sensor for the tip electrode 60 instead of the thermocouple cable 52.

Further, the tip of the water supply tube 53 for supplying cooling water to the inside thereof is inserted into the tip electrode 60. The water supply tube 53 extends to the inner hole of the puncture needle 6, extends from the proximal end of the electrically insulating thin tube 70 to the inner hole of the gripping portion 40, and further extends to the inner hole of the gripping portion 40 to grip It penetrates the base end wall 41 of the portion 40. The proximal end of the water supply tube 53 is connected to a cooling water supply source (not shown).
The cooling water supplied from the distal end opening of the water supply tube 53 is formed so as to penetrate the proximal end wall 41 through the inner hole of the puncture needle 6 and the inner hole of the grasping portion 40 after cooling the distal end electrode 60 from the inside. The discharged drain tube 54 is discharged.

  As shown in FIG. 3, the tip portion of the electrically insulating thin tube 70 is formed so as to cover the outer surface of the flange portion 62 of the tip electrode 60. As a result, a sufficient bonding area between the tip electrode 60 and the electrically insulating thin tube 70 can be secured, and the two are prevented from being firmly coupled and separated due to a drop-off preventing effect due to the flange shape. As a result, during the operation with the puncture needle 6 of the present embodiment, for example, when the puncture needle 6 is removed, an accident in which the tip electrode 60 is dropped from the electrically insulating thin tube 70 and is left in the body is ensured. Can be prevented.

  It is preferable that the tip electrode 60 and the electrically insulating thin tube 70 constituting the puncture needle 6 of the present embodiment are integrally formed by insert molding. Specifically, there is a method in which after the tip electrode 60 is disposed in a mold, a curable resin for forming the electrically insulating thin tube 70 is cast and cured by injection molding or the like. Thus, the outer surface of the flange portion 62 of the tip electrode 60 is covered with the tip portion (cured resin) of the electrically insulating thin tube 70, so that the tip electrode 60 and the electrically insulating thin tube 70 are firmly coupled. A connector (puncture needle 6) can be manufactured. In addition, the lead wire 51, the thermocouple cable 52, the water supply tube 53, etc. may be connected to the tip electrode 60 arrange | positioned in a metal mold | die.

The puncture needle 6 of this embodiment is similar to the ablation puncture needle 1 according to the reference embodiment , as shown in FIG. 2, such as a radiofrequency ablation therapy system (cauterization puncture needle 6, radio wave generator 2, counter electrode). Plate 3, a cooling water supply source 4, and a drainage storage tank 5), and ablation therapy can be performed in the same manner as in the reference embodiment .

  That is, after setting up the system, the tip electrode 60 of the puncture needle 6 is punctured into a lesioned part of a patient while monitoring an ultrasonic image. At this time, normal tissue exists around the portion other than the distal electrode 60 (electrically insulating thin tube 70) of the puncture needle 6, and the proximal end portion of the puncture needle 6 is in contact with the body surface of the patient.

In this state, when starting the energization, the radiofrequency current from the radio wave generator, flows through the body of a patient through the leads 51 and puncture needle 6, the counter electrode plate and adhered to the vicinity of the thigh of the patient refluxing the radio wave generator via a lead wire. Then, Joule heat is generated in the living tissue by the radio wave current flowing between the puncture needle 6 and the counter electrode plate. Thereby, the lesioned part becomes high temperature and cauterized, and the lesioned tissue is coagulated and necrotized.

In the puncture needle 6 of the present embodiment, the portion other than the tip electrode 60 is configured by the electrically insulating thin tube 70, so that no high frequency current is passed through the electrically insulating thin tube 70.
Further, since the material (resin) constituting the electrically insulating thin tube 70 has a remarkably lower thermal conductivity than that of the metal, the electrically insulating thin tube 70 does not become hot due to the heat generated at the tip electrode 60. Therefore, according to the puncture needle 6 of the present embodiment, normal tissue existing around the portion other than the distal electrode 60 (electrically insulating thin tube 70) and the proximal end portion of the puncture needle 6 (electrically insulating thin tube 70). There is no thermal damage to the patient's body surface in contact with

  In addition, since the radio wave current from the radio wave generator is energized only to the tip electrode 60, the lesion punctured by the tip electrode 60 with lower high-frequency energy than the conventionally known cauterization puncture needle that is the entire energization region. The part can be cauterized intensively.

DESCRIPTION OF SYMBOLS 1 Puncture needle for cauterization 2 Radio wave generator 3 Counter electrode 4 Cooling water supply source 5 Drainage storage tank 6 Puncture needle for cauterization 10 Tip electrode 11 Tip end portion of tip electrode 12 Flange portion 20 Electrical insulating connecting tube 30 Metal tubule 32 Flange portion 40 Grasping portion 41 Base end wall 51 Lead wire 52 Thermocouple cable 53 Water supply tube 54 Drain tube 55 Lead wire 60 Tip electrode 61 Tip electrode tip portion 62 Flange portion 70 Electrical insulating capillary

Claims (4)

A sharp tip electrode through which a high-frequency current is passed between the counter electrode plate and
A hard electrically insulating capillary having the rigidity required for the ablation puncture needle connected to the proximal side of the distal electrode;
An ablation puncture needle in which the tip electrode includes a sharp tip portion and a flange portion for preventing dropout, and an outer surface of the flange portion is covered with a tip portion of the electrically insulating thin tube. The cautery puncture needle according to claim 1 , wherein the electrically insulating thin tube is made of a resin. The ablation puncture needle according to claim 2 , wherein the tip electrode and the electrically insulating thin tube are integrally formed by insert molding. The ablation puncture needle according to any one of claims 1 to 3 , further comprising a cooling means for cooling the tip electrode by circulating water inside the tip electrode.

Images