JP6846746B2 - Radiofrequency treatment catheter - Google Patents

Description

The present invention relates to a catheter that treats an affected area using high frequency.

Conventionally, as a method of treating an affected area generated in a living body such as an adrenal gland, a catheter having a needle-shaped electrode portion installed at the tip is used, and a high-frequency current is applied from the electrode portion to the affected area to cauterize and treat the affected area. The method is known (see Patent Document 1).

The temperature of the electrode portion and the tissue near the electrode portion may become too high while the high-frequency current is applied. In order to suppress this, a technique is known in which a saline solution is circulated in the catheter tube to cool the electrode portion (see Patent Document 2). Further, a technique of installing a temperature sensor in the electrode portion is known in order to measure the temperature of the tissue in the vicinity of the electrode portion.

JP 2012-170777 JP 2013-163019

In a catheter for high-frequency treatment in which the electrode portion is cooled by a refrigerant such as saline, the refrigerant is used when the temperature of the tissue near the electrode portion is measured by a temperature sensor installed in the electrode portion while a high-frequency current is applied. It has become difficult to measure the temperature of the tissue more accurately due to the cooling effect of the above.

The present invention has been made in view of these problems, and an object of the present invention is to more accurately measure the tissue temperature in the vicinity of the electrode portion in a catheter for high frequency therapy in which the electrode portion is cooled by a refrigerant such as saline solution. It is in the provision of technology that can be done.

One embodiment of the present invention is a radiofrequency therapeutic catheter that is inserted into an adrenal vein. The high-frequency therapeutic catheter is provided at a flexible tube, a guide wire lumen for passing the guide wire through the tube, and a distal end of the tube, and cauterizes the tissue by high-frequency heat. A needle-shaped electrode portion for measuring, a temperature sensor for measuring the tissue temperature in the vicinity of the electrode portion, an electric wire connected to the temperature sensor and inserted into the tube, and arranged in the tube. It is provided with one or a plurality of refrigerant introduction pipes through which a refrigerant for cooling the electrode portion is circulated, and is provided on a tapered outer surface extending from the base portion to the cutting edge of the electrode portion on the central axis of the electrode portion. A groove extending along the groove is provided, the electric wire has a shape bent at a distal portion, at least a part of the electric wire distal to the bent portion is embedded in the groove, and the temperature sensor is the groove. It is embedded in the distal end of the.

In the high-frequency treatment catheter of the above aspect, a recess deeper than the other portion may be provided in the distal portion of the groove, and the temperature sensor larger than the outer diameter of the electric wire may be fitted in the recess. Further, the electrode portion has three tip cut surfaces, and the distal opening of the guide wire lumen communicates with a through hole provided so as to cut out two surfaces of the tip cut surface, and the tip thereof. The groove, a part of the electric wire, and the temperature sensor may be provided on the remaining one surface of the cut surface.

It should be noted that an appropriate combination of the above-mentioned elements may be included in the scope of the invention for which protection by the patent is sought by the present patent application.

According to the present invention, in a catheter for high frequency therapy in which the electrode portion is cooled by a refrigerant such as saline solution, the tissue temperature in the vicinity of the electrode portion can be measured more accurately.

It is a schematic overall view of the high frequency treatment catheter which concerns on embodiment. FIG. 2A is a plan view of a main part of the shaft portion and the electrode portion. FIG. 2B is a cross-sectional view taken along the line AA of FIG. 2A. It is a side view of the main part of a shaft part and an electrode part. It is a perspective view of the main part of a shaft part and an electrode part. It is sectional drawing which shows the internal structure of the shaft part, and is taken along the line BB of FIG. 2 (a). It is sectional drawing which shows the internal structure of the base part of an electrode part. It is a front view which shows the structure of the tip part of an electrode part. It is sectional drawing which shows the internal structure of a branch part.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by the same reference numerals, and description thereof will be omitted as appropriate.

FIG. 1 is a schematic overall view of the high frequency therapeutic catheter 10 according to the embodiment. The high-frequency therapeutic catheter 10 of the present embodiment is suitably used for treatment in which a tissue such as a tumor formed in the adrenal gland is cauterized by high-frequency heat, which is inserted into the adrenal vein.

The high frequency treatment catheter 10 has a shaft portion 20, an electrode portion 30, a branch portion 40, a plurality of branch tubes, and connectors.

FIG. 2A is a plan view of a main part of the shaft portion 20 and the electrode portion 30. FIG. 2B is a cross-sectional view taken along the line AA of FIG. 2A. FIG. 3 is a side view of a main part of the shaft portion 20 and the electrode portion 30. FIG. 4 is a perspective view of a main part of the shaft portion 20 and the electrode portion 30. FIG. 5 is a cross-sectional view taken along the line BB of FIG. 2A showing the internal structure of the shaft portion 20.

The shaft portion 20 is a long cylindrical member, and has a metal tube 21, a heat-shrinkable tube 22, a guide wire tube 23, a first refrigerant introduction pipe 24, and a second refrigerant introduction pipe 25.

The metal tube 21 is provided with a spiral notch 26, and is designed so that the pitch between the notches 26 becomes shorter toward the distal side. As a result, the flexibility of the metal tube 21 becomes better toward the distal side. Examples of the material of the metal tube 21 include a metal material such as SUS or NiTi alloy.

The outside of the metal tube 21 is coated with an insulating heat shrink tube 22. The heat shrink tubing 22 holds the metal tubing 21 together. Further, when the shaft portion 20 is inserted into a blood vessel or the like, damage to the inner wall of the blood vessel or the like is suppressed. The heat shrink tube 22 may be embedded in the notch 26 of the metal tube 21. According to this, the notch 26 of the metal tube 21 is suppressed from unnecessarily expanding. Examples of the material of the insulating heat-shrinkable tube 22 include polyolefin and Teflon (registered trademark).

A guide wire tube 23, a first refrigerant introduction pipe 24, and a second refrigerant introduction pipe 25 are inserted into the metal tube 21 (see FIG. 5).

The guide wire lumen 27 is formed as a lumen of the guide wire tube 26. Examples of the material of the guide wire tube 26 include a thermoplastic resin such as polyetheretherketone (PEEK).

The guide wire lumen 27 is installed so as to be detached from the central axis 28 of the metal tube 21. This makes it easier to secure the installation space for the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25, which will be described later.

The first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 are hollow members for circulating refrigerants such as water, physiological saline, ethylene glycol, and ethylene glycol aqueous solution, respectively. Examples of the material of the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 include thermoplastic resins such as polyetheretherketone (PEEK). In the present embodiment, the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 are independent pipes. The temperature of the refrigerant supplied to the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 is preferably −20 to 10 ° C. The flow rate of the refrigerant supplied to the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 is preferably 10 to 100 ml / min, more preferably 30 to 70 ml / min. The temperature and flow rate of the refrigerant are appropriately set so that the temperature of the tissue near the electrode portion 30 is 65 ° C. or lower, but if the temperature of the refrigerant is too low, the affected area cannot be sufficiently cauterized, and the refrigerant If the temperature is too high, a steam explosion of the tissue will occur.

The sum S1 of the inner cross-sectional area of the first refrigerant introduction pipe 24 in the orthogonal axis direction and the inner cross-sectional area of the second refrigerant introduction pipe 25 in the orthogonal axis direction is 10 to 52 of the inner cross-sectional area S2 of the metal tube 21 in the orthogonal axis direction. % Is preferable, and 25-40% is more preferable. By setting the total inner cross-sectional area S1 to 10% or more of the inner cross-sectional area S2, the amount of the refrigerant required for cooling the electrode portion 30 can be made sufficient. On the other hand, when the total inner cross-sectional area S1 is larger than 52% of the inner cross-sectional area S2, the applicable guide wire diameter becomes smaller and the operability deteriorates.

The electrode portion 30 has a cylindrical base portion 31 and a distal end portion 32 on the distal side of the base portion 31. Examples of the material of the electrode portion 30 include a metal material such as SUS or NiTi alloy. FIG. 6 is a cross-sectional perspective view showing the internal structure of the base portion 31 of the electrode portion 30. FIG. 7 is a front view showing the structure of the tip end portion 32 of the electrode portion 30. The tips of the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 are located in the base 31, and the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 are in contact with the inner wall of the base 31. As a result, the cooling efficiency of the electrode portion 30 is improved. When a liquid harmless to the human body such as water or physiological saline is used as the refrigerant, a minute passage (not shown) communicating with the base 31 and the first refrigerant introduction pipe 24, and / or the base 31 and the first (2) A minute passage (not shown) communicating with the refrigerant introduction pipe 25 may be provided and ejected from the electrode portion 30 to the outside. According to this, the tissue close to the electrode portion 30 can be directly cooled by the refrigerant, and the structure can be cooled more efficiently.

In the base portion 31, a cylindrical hollow guide wire lumen tube fixing tube 33 made of the same material as the base portion 31 is integrally formed by laser welding. Inside the guide wire lumen tube fixing tube 33, the tip portion of the guide wire lumen tube 26 made of a flexible resin material is fixed by an adhesive. As a result, a sufficient adhesive area can be secured, and the guide wire lumen tube 26 is electrode compared with the case where the end portion of the guide wire lumen tube 26 is joined and fixed to the opening 37 of the electrode portion 30. It can be securely fixed to the portion 30.

At the tip portion 32, a tapered outer surface extending from the base portion 31 to the tip end (cutting edge) 39 is formed. In the present embodiment, the cutting edge 39 is formed by a plurality of flat tip cut surfaces. Specifically, the tip portion 32 has a total of three surfaces, a first surface P1, a second surface P2, and a third surface P3, as the tip cut surface. The tip portion 32 is provided with a through hole 34 which communicates with the hollow portion of the base portion 31 and has an opening on the first surface P1. Further, a groove 38 extending along the central axis of the electrode portion 30 is provided on the distal side from the opening of the through hole 34. In other words, the first surface P1 of the tip portion 32 is provided with a groove 38 from the opening of the through hole 34 toward the tip end 39. Further, a recess 130 deeper than the other portion is provided at the distal end of the groove 38.

The electric wire 36 connected to the temperature sensor 35 has a shape bent at the distal portion. Examples of the temperature sensor 35 include a thermocouple thermometer. A part of the electric wire 36 distal to the bent portion is fitted in the groove 38, and the temperature sensor 35 is fitted in the distal end of the groove 38. The entire electric wire 36 on the distal side of the bent portion may be fitted into the groove 38. The depth of the groove 38 is appropriately designed to be sufficiently deep enough to fit the electric wire 36 completely. In the present embodiment, the size of the temperature sensor 35 is larger than the outer diameter of the electric wire 36, and the temperature sensor 35 is fitted in the recess 130 described above. The depth of the recess 130 is the same as the surface of the temperature sensor 35 and the first surface P1 in the groove 38 without the temperature sensor 35 protruding outward from the first surface P1 when the temperature sensor 35 is fitted in the recess 130. It is designed so that the shortest distance to the surface is close. Further, the width of the recess 130 is designed to be larger than the width of other parts of the groove 38 according to the size of the temperature sensor 35. The shape of the recess 130 is designed according to the shape of the temperature sensor 35. For example, when the shape of the temperature sensor is spherical, it is preferable that the recess 130 is hemispherical. The recess 130 is not essential, and if the size of the temperature sensor 35 is the same as the outer diameter of the electric wire 36, the temperature sensor 35 may be embedded in the distal portion of the groove 38 having a constant depth. A part of the temperature sensor 35 and the electric wire 36 distal to the bent portion is fixed to the groove 38 with an adhesive or the like. The electric wire 36 passes through the inside of the through hole 34 and the base 31, and is introduced into the space between the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 in the metal tube 21.

The tip 39 of the tip 32 is located at or near the central axis of the metal tube 21. The vicinity of the central axis of the metal tube 21 means within 40% of the radius of the metal tube 21 from the central axis of the metal tube 21. As described above, in the present embodiment, the cutting edge 39 of the tip portion 32 is designed to be located away from the outer circumference of the electrode portion 30. In the high-frequency treatment catheter 10 according to the present embodiment, the tissue can be torn by using the cutting edge 39 of the tip portion 32, so that the electrode portion 30 can be easily reached to the affected portion requiring treatment. ..

The tip portion 32 having a tip cut surface as in the present embodiment can be easily formed by using a columnar material and cutting out with a cutting tool such as a lathe, thereby reducing the manufacturing cost and processing. The accuracy can be improved.

Further, the tip portion 32 is formed with an opening 37 that cuts out the second surface P2 and the third surface P3. The proximal side of the opening 37 communicates with the distal end of the guide wire lumen tube fixing tube 33.

FIG. 8 is a cross-sectional view showing the internal structure of the branch portion 40. The proximal side of the metal tube 21 and the heat shrink tubing 22 is connected to the branch 40. The branch portion 40 has a common connection path 41, a first connection path 42, a second connection path 43, and a third connection path 44.

An electric wire 36 connected to the temperature sensor 35, an electric wire (not shown) connected to the electrode portion 30, a first refrigerant introduction pipe 24, and a second refrigerant introduction pipe 25 are introduced into the common connection path 41. The first connecting path 42 and the second connecting path 43 are connected to the proximal side of the common connecting path 41. An electric wire connected to the electric wire 36 and the electrode portion 30 is inserted into the first connecting path 42. The first branch pipe 50 is connected to the proximal side of the first connecting path 42, and the electric wire 36 and the electric wire connected to the electrode portion 30 are inserted into the first branch pipe 50 and proximal to the first branch pipe 50. It is connected to the electric connector 60 attached to the side. A power source for supplying high-frequency power to the electrode portion 30 and a computer to which a temperature signal obtained by the temperature sensor 35 is input are connected to the electric connector 60.

The first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 extend to the outside of the branch portion 40 through the second connecting path 43, and are proximal to the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25. Cooling medium connectors 61 and 62 are attached to the sides, respectively. By connecting well-known pipes (not shown) to the cooling medium connectors 61 and 62, and installing a well-known pump (not shown) and a cooler (not shown), the catheter 10 for high-frequency treatment can be used. The structure is such that the refrigerant can be supplied into the high-frequency treatment catheter 10 from the outside.

The third connecting path 44 communicates with the guide wire lumen 27 on the distal side and communicates with the second branch pipe 51 on the proximal side. A guide wire connector 63 is attached to the proximal side of the first branch pipe 51.

According to the high-frequency treatment catheter 10 described above, the groove 38 is formed in the tapered first surface P1 leading to the tip end 39 of the tip end portion 32 of the electrode portion 30, and the bent portion of the electric wire 36 connected to the temperature sensor 35. The temperature sensor 35 is arranged on the distal side of the electrode portion 30 by fitting at least a part of the more distal portion into the groove 38 and setting the temperature sensor 35 at the distal end of the groove 38. Can be done. As a result, the temperature sensor 35 can be separated from the distal ends of the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 by the amount of the groove 38, and the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 can be separated. It is possible to measure the temperature of the tissue more accurately by making it less susceptible to the cooling effect of the refrigerant flowing through.

Further, by fitting at least a part of the temperature sensor 35 and the electric wire 36 distal to the bent portion into the groove 38 provided in accordance with the dimensions of the bent portion of the temperature sensor 35 and the electric wire 36. The distal portion of the temperature sensor 35 and the bent portion of the electric wire 36 is positioned, and the temperature sensor 35 does not protrude outward from the first surface P1, and the surface of the temperature sensor 35 and the same surface as the first surface P1 are formed in the groove 38. The shortest distance to and can be brought close. As a result, it is possible to reduce the labor required for assembling the temperature sensor 35 and to improve the assembling accuracy of the temperature sensor 35.

Further, according to the size of the temperature sensor 35, by providing the recess 130 at the distal end of the groove 38, the temperature sensor 35 is fitted into the recess 130, so that the positioning when assembling the temperature sensor 35 is performed more accurately. be able to.

Further, when the electrode portion 30 is introduced into the tissue to be treated and is inserted into a blood vessel or the like, a space can be secured between the cutting edge 39 of the electrode portion 30 and the inner wall of the blood vessel or the like, so that the electrode portion The tip 32 of 30 can prevent damage to the inner wall such as a blood vessel.

Further, since the tip 39 of the electrode portion 30 is located at or near the central axis 28 of the metal tube 21, the guide wire lumen 27 is formed so as to avoid the tip 39 of the electrode portion 30, so that the electrode portion is formed. The 30 and the shaft portion 20 can be inserted along the guide wire in the curved blood vessel, and the tissue is pierced by using the cutting edge 39 of the electrode portion 30 without damaging the inner wall of the blood vessel as described above. Or, it becomes possible to tear it apart and proceed.

Further, by adopting a so-called internal cooling type in which the electrode portion 30 is cooled by the refrigerant circulating in the first refrigerant introduction pipe 24 and the second refrigerant introduction pipe 25 inserted into the metal tube 21, the vicinity of the electrode portion 30 is formed. The temperature of the tissue rises to 65 ° C. or higher, and scorching is suppressed. As a result, it is possible to suppress an increase in the resistance value in the vicinity of the electrode portion 30 and perform treatment with a high frequency more efficiently.

The present invention is not limited to the above-described embodiment, and various modifications such as design changes can be made based on the knowledge of those skilled in the art. It can be included in the scope of the invention.

In the above-described embodiment, two refrigerant introduction pipes are provided, but one refrigerant introduction pipe is used, and the inner cross-sectional area of the refrigerant introduction pipe is 10 to 10 of the inner cross-sectional area S2 of the metal tube 21 in the direction orthogonal to the axis. It may be 32%, more preferably 23 to 32%.

10 High frequency treatment catheter, 20 shaft part, 21 metal tube, 22 heat shrinkable tube, 23 guide wire tube, 24 first refrigerant introduction tube, 25 second refrigerant introduction tube, 30 electrode part, 31 base part, 32 tip part, 33 Lumen tube fixing tube for guide wire, 35 Temperature sensor, 36 Wire, 37 Opening, 38 Groove, 39 Cutting edge, 40 Branch, 41 Common connection path, 42 1st connection path, 43 2nd connection path, 44th 3 connection path, 50 1st branch pipe, 51 2nd branch pipe, 60 electrical connector, 61 cooling medium connector, 62 cooling medium connector, 63 guide wire connector, 130 recess

Claims (3)

A high-frequency therapeutic catheter that is inserted into the adrenal vein.
Flexible tubes and
A lumen for the guide wire for penetrating the tube and passing the guide wire,
A needle-shaped electrode portion provided at the distal end of the tube for cauterizing tissue by high-frequency heat, and
A temperature sensor for measuring the tissue temperature in the vicinity of the electrode portion, and
An electric wire connected to the temperature sensor and inserted into the tube,
One or more refrigerant introduction pipes arranged in the tube and circulating a refrigerant for cooling the electrode portion,
With
A groove extending along the central axis of the electrode portion is provided on the tapered outer surface from the base portion to the tip portion of the electrode portion.
The electric wire has a shape bent at the distal portion, at least a part of the electric wire distal to the bent portion is embedded in the groove, and the temperature sensor is embedded in the distal end of the groove. A catheter for high frequency therapy characterized by. A recess deeper than the other portion is provided in the distal portion of the groove.
The catheter for high-frequency treatment according to claim 1, wherein the temperature sensor having a diameter larger than the outer diameter of the electric wire is fitted in the recess. The electrode portion has three tip cut surfaces.
The distal opening of the guide wire lumen communicates with a through hole provided so as to cut out two surfaces of the tip cut surface.
The catheter for high frequency therapy according to claim 1 or 2, wherein the groove, a part of the electric wire, and the temperature sensor are provided on the remaining one surface of the tip cut surface.

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