JP7579449B2 - Balloon-type electrode catheter - Google Patents

Description

The present invention relates to a balloon-type electrode catheter that is introduced intravascularly and used to perform radiofrequency ablation treatment of a blood vessel or the tissue surrounding it.

Conventionally, an electrode catheter for performing radiofrequency ablation treatment on a blood vessel or the tissue surrounding it has been provided with an outer tube having a central lumen and a plurality of sub-lumens arranged around the central lumen, an electric connector arranged on the base end side of the outer tube, an expandable and contractible expansion section, and neck sections connected to both ends of the expansion section, the base end neck section being fixed to the tip end of the outer tube to connect the balloon to the tip end side of the outer tube, an inner tube having a lumen through which a guidewire can be inserted, which is inserted into the central lumen of the outer tube and extends from the opening of the central lumen into the balloon and extends inside the balloon, and a lumen communicating with the lumen of the inner tube, and the inner tube is inserted into the balloon. The present applicant has proposed a balloon-type electrode catheter comprising: a distal tip connected to the distal end of a tube and fixed to the distal neck portion and extending to the outside of the balloon; a surface electrode (strip electrode) made of a thin metal film formed on the outer surface of the balloon at the expansion portion and the distal neck portion; a metal ring attached to the distal neck portion of the balloon and having a distal end of the surface electrode fixed to its outer peripheral surface, thereby electrically connecting the surface electrode; and a conductor having a distal end fixed to the inner peripheral surface of the metal ring, extending into the interior of the balloon and into one of the sublumens of the outer tube, and having a base end fixed to the current-carrying connector, thereby electrically connecting the surface electrode and the current-carrying connector (see Patent Document 1 below).

The balloon that constitutes this balloon-type electrode catheter has an expansion section that expands and contracts, a base end neck section that is continuous with the base end of the expansion section, and a tip end neck section that is continuous with the tip of the expansion section. The expansion section of the balloon consists of a cylindrical section, a tip end cone section that extends from the tip of the cylindrical section to the base end of the tip end neck section, and a base end cone section that extends from the base end of the cylindrical section to the tip of the base end neck section.

The surface electrodes that make up this balloon-type electrode catheter are formed on the outer surfaces of the cylindrical portion of the expansion section, the distal cone portion, and the distal neck portion.

With this balloon-type electrode catheter, the surface electrode formed on the outer surface of the balloon can be electrically connected to the current-carrying connector via a metal ring and a conductor, so that high-frequency current can be reliably passed through the surface electrode.

International Publication No. 2020/35918

When a balloon-type electrode catheter such as that described in Patent Document 1 is used to cauterize a narrowed or blocked blood vessel or the tissue surrounding it, the cylindrical part of the balloon expansion section, which has a surface electrode formed on its outer surface, is brought into contact with the blood vessel (inner wall) to be treated, and the blood vessel is cauterized while being expanded.

However, in the balloon-type electrode catheter described in Patent Document 1, surface electrodes are formed not only on the cylindrical portion of the expansion section, but also on the outer surface of the distal cone portion and distal neck portion of the expansion section. This means that the vascular area in contact with the distal cone portion, etc., is cauterized without being sufficiently expanded, which may result in (re)stenosis of the vascular area.

The present invention has been made based on the above circumstances.
The object of the present invention is to provide a balloon-type electrode catheter that can perform cauterization treatment on a blood vessel or the diseased tissue surrounding it using the cylindrical portion of the balloon expansion part, without cauterizing the blood vessel part or the surrounding tissue that is in contact with the cone part of the expansion part.

(1) The balloon-type electrode catheter of the present invention is a balloon-type electrode catheter that is introduced intravascularly and used for cauterizing a blood vessel or tissue surrounding the blood vessel,
an outer tube having a central lumen and a plurality of sub-lumens disposed around the central lumen;
an electrical connector disposed on a base end side of the outer tube;
a balloon having an expansion section consisting of a distal cone section, a cylindrical section, and a proximal cone section, and neck sections continuous with both ends of the expansion section, the proximal neck section being fixed to the distal end section of the outer tube, thereby being connected to the distal end side of the outer tube;
an inner tube having a lumen through which a guide wire can be inserted, the inner tube being inserted into the central lumen of the outer tube, extending from an opening of the central lumen into the balloon, and extending through the balloon;
a distal tip having a lumen communicating with the lumen of the inner tube, connected to the distal end of the inner tube inside the balloon, and fixed to the neck portion on the distal end side (distal end neck portion) and extending to the outside of the balloon;
a metal ring attached to the distal neck portion or the proximal neck portion;
a surface electrode made of a thin metal film electrically connected to the metal ring and formed on the outer surface of the neck portion (the distal end neck portion or the proximal end neck portion) to which the metal ring is attached, the cone portion (the distal end cone portion or the proximal end cone portion) of the extension portion continuous with the neck portion, and the cylindrical portion of the extension portion;
a conductive wire having a tip fixed to an inner circumferential surface of the metal ring, extending into the interior of the balloon and into any one of the sub-lumens of the outer tube, and having a base end fixed to the current-carrying connector, thereby electrically connecting the surface electrode and the current-carrying connector;
The present invention is characterized in that the electrode portion formed on the outer surface of the cone portion (the distal cone portion or the proximal cone portion) that is continuous with the neck portion (the distal neck portion or the proximal neck portion) to which the metal ring is attached is insulated.

With a balloon-type electrode catheter configured in this manner, cauterization treatment can be performed on the blood vessel or the diseased tissue surrounding it using the cylindrical portion of the balloon expansion section, and since the electrode portion formed on the cone portion of the expansion section that is continuous with the neck portion to which the metal ring is attached is insulated, the area near this electrode portion does not become hot during cauterization treatment, and the blood vessel portion in contact with this cone portion (insulating coating layer) and the surrounding tissue can be prevented from being cauterized, thereby preventing (re)narrowing of the blood vessel portion.

(2) In the balloon-type electrode catheter of the present invention, the metal ring is attached to the distal neck portion,
the surface electrode is formed on an outer surface of the distal neck portion, the distal cone portion of the extension portion, and the cylindrical portion;
It is preferable that the electrode portion formed on the outer surface of the tip side cone portion is insulated.

With a balloon-type electrode catheter having such a configuration, the electrode portion formed on the outer surface of the distal cone portion of the expansion section is insulated, so that the vicinity of this electrode portion does not become hot during cauterization treatment, and the vascular area in contact with the distal cone portion (insulating coating layer) and the surrounding tissue can be prevented from being cauterized, thereby preventing (re)stenosis of the vascular area.

Furthermore, since the surface electrode formed on the outer surface of the balloon can be electrically connected to the current-carrying connector via a metal ring and a conductive wire, high-frequency current can be reliably passed through the surface electrode.
This makes it possible to perform cauterization treatment over a wide range of areas, including blood vessels and the diseased tissue surrounding them.

In addition, the distal neck portion of the balloon to which the metal ring is attached is the neck portion fixed to the distal tip, and has a significantly smaller outer diameter than the proximal neck portion fixed to the outer tube, so the outer diameter of the metal ring attached to the distal neck portion can be made smaller than the outer diameters of the outer tube and the proximal neck portion.
This prevents the metal ring from getting caught in the opening of the sheath or endoscope being used when introducing the balloon electrode catheter, and ensures that the insertability of the balloon electrode catheter into the lumen of the sheath or endoscope is not impaired.

(3) In the balloon-type electrode catheter of (2) above, it is preferable that the electrode portions formed on the outer surface of the distal neck portion, the distal cone portion of the expansion portion, and the distal region of the cylindrical portion are insulated.
Here, the "tip region" of the cylindrical portion refers to a region having a certain length including the tip of the cylindrical portion.

With a balloon-type electrode catheter having such a configuration, the electrode portions formed on the outer surfaces of the distal neck portion and the distal cone portion of the expansion portion are insulated, so that the vicinity of these electrode portions does not become hot during cauterization treatment.

Furthermore, in this balloon-type electrode catheter, the electrode portion formed on the outer surface of the tip region of the cylindrical portion is insulated, so that the tip cone portion can be prevented from becoming hot due to heat conduction from the tip region.
This makes it possible to more effectively prevent the vascular site in contact with the distal neck portion and the distal cone portion (insulating coating layer) of the expansion portion and the surrounding tissue from being cauterized.

In addition, by appropriately adjusting the length of the tip region (length of the insulating coating), it is possible to heat the tip region by thermal conduction from areas of the cylindrical portion other than the tip region (areas where the electrode portion is not insulatingly coated), and perform cauterization treatment of the vascular site in contact with the tip region or the tissue surrounding it (making the entire cylindrical portion the cauterization treatment area).

(4) In the balloon electrode catheter of (3) above, it is preferable that the length of the tip region of the cylindrical portion is 1 to 3 mm.

A balloon-type electrode catheter having such a configuration can more effectively prevent cauterization of the vascular area and surrounding tissue that are in contact with the distal neck portion and the distal cone portion (insulating coating layer) of the expansion portion, and can perform cauterization treatment over the entire cylindrical portion, including the distal region.

(5) In the balloon-type electrode catheter of (3) or (4) above, it is preferable that the metal ring is insulated.

A balloon-type electrode catheter having such a configuration can prevent the metal ring from becoming too hot when electricity is applied during ablation treatment, and can avoid cauterizing the tissue around the metal ring.

(6) In the balloon electrode catheter according to any one of (3) to (5) above, the surface electrode is formed up to the base end position of the cylindrical portion,
It is preferable that the electrode portion formed on the outer surface of the base end region of the cylindrical portion is insulated.
Here, the "proximal region" of the cylindrical portion refers to a region having a certain length including the proximal end of the cylindrical portion.

With a balloon-type electrode catheter having such a configuration, the electrode portion formed in the base end region of the cylindrical portion of the expansion section is insulated, so that during cauterization treatment, the base end cone portion can be prevented from heating up due to heat conduction from the base end region, thereby preventing the vascular site in contact with the base end cone portion and the surrounding tissue from being cauterized.

In addition, by appropriately adjusting the length of the base end region (length of the insulating coating), it is possible to heat the base end region by thermal conduction from areas of the cylindrical portion other than the base end region (areas where the electrode portion is not insulatingly coated), and perform cauterization treatment of the vascular site in contact with the base end region or the tissue surrounding it (making the entire cylindrical portion the cauterization treatment area).

(7) In the balloon-type electrode catheter of (6) above, it is preferable that the length of the base end region of the cylindrical portion is 1 to 3 mm.

A balloon-type electrode catheter having such a configuration can more effectively prevent the vascular area in contact with the base-end cone portion and the surrounding tissue from being cauterized, and can perform cauterization treatment over the entire cylindrical portion, including the base-end region.

(8) In the balloon-type electrode catheters of (2) to (7) above, it is preferable that the surface electrode is formed to extend along the axial direction of the balloon and consists of a plurality of band-shaped electrodes arranged at equal angular intervals along the circumferential direction of the balloon, and that the tip of each of the band-shaped electrodes is fixed to the outer peripheral surface of the metal ring, thereby electrically connecting each of the band-shaped electrodes to the metal ring.

With a balloon-type electrode catheter configured in this manner, each of the multiple band-shaped electrodes formed at equal angular intervals along the circumferential direction of the balloon can be electrically connected to the current-carrying connector via a metal ring and a conductor, allowing high-frequency current to be passed evenly through each of the multiple band-shaped electrodes, thereby enabling uniform cauterization treatment of a blood vessel or the tissue surrounding it along the circumferential direction of the vessel.

(9) In the balloon electrode catheter of the present invention, the metal ring is attached to the base end side neck portion,
the surface electrode is formed on an outer surface of the proximal neck portion, the proximal cone portion of the extension portion, and the cylindrical portion;
It is preferable that the electrode portion formed on the outer surface of the base end side cone portion is insulated.

With a balloon-type electrode catheter having such a configuration, the electrode portion formed on the outer surface of the base-end cone portion of the expansion section is insulated. This prevents the area around this electrode portion from becoming hot during cauterization treatment, and prevents the vascular area in contact with the base-end cone portion (insulating coating layer) and the surrounding tissue from being cauterized. This makes it possible to prevent (re)stenosis of the vascular area.

(10) In the balloon-type electrode catheter of (9) above, it is preferable that the electrode portions formed on the outer surface of the base-end neck portion, the base-end cone portion of the expansion portion, and the base-end region of the cylindrical portion are insulated.

With a balloon-type electrode catheter having such a configuration, the electrode portions formed on the outer surfaces of the base-end neck portion and the base-end cone portion of the expansion portion are insulated, so that the vicinity of these electrode portions does not become hot during cauterization treatment.

Furthermore, in this balloon-type electrode catheter, the electrode portion formed on the outer surface of the base end region of the cylindrical portion is insulated, so that the base end cone portion can be prevented from rising in temperature due to heat conduction from the base end region.
This makes it possible to more effectively prevent the vascular site in contact with the base-end neck portion and the base-end cone portion (insulating coating layer) of the expansion portion and the surrounding tissue from being cauterized.

In addition, by appropriately adjusting the length of the base end region (length of the insulating coating), it is possible to heat the base end region by thermal conduction from areas of the cylindrical portion other than the base end region (areas where the electrode portion is not insulatingly coated), and perform cauterization treatment of the vascular site in contact with the base end region or the tissue surrounding it (making the entire cylindrical portion the cauterization treatment area).

(11) In the balloon-type electrode catheter of (10) above, it is preferable that the length of the base end region of the cylindrical portion is 1 to 3 mm.

A balloon-type electrode catheter having such a configuration can more effectively prevent cauterization of the vascular area and surrounding tissue that are in contact with the base-end neck portion and the base-end cone portion (insulating coating layer) of the expansion portion, and can perform cauterization treatment over the entire cylindrical portion, including the base-end region.

(12) In the balloon-type electrode catheter of (10) or (11) above, it is preferable that the metal ring is insulated.

A balloon-type electrode catheter having such a configuration can prevent the metal ring from becoming too hot when electricity is applied during ablation treatment, and can avoid cauterizing the tissue around the metal ring.

(13) In the balloon electrode catheter according to any one of (10) to (12), the surface electrode is formed up to the tip position of the cylindrical portion,
It is preferable that the electrode portion formed on the outer surface of the tip region of the cylindrical portion is insulated.

With a balloon-type electrode catheter configured in this manner, the electrode portion formed in the tip region of the cylindrical portion of the expansion section is insulated, so that during cauterization treatment, the tip cone portion can be prevented from heating up due to heat conduction from the tip region, thereby preventing the vascular site in contact with the tip cone portion and the surrounding tissue from being cauterized.

In addition, by appropriately adjusting the length of the tip region (length of the insulating coating), it is possible to heat the tip region by thermal conduction from areas of the cylindrical portion other than the tip region (areas where the electrode portion is not insulatingly coated), and perform cauterization treatment of the vascular site in contact with the tip region or the tissue surrounding it (making the entire cylindrical portion the cauterization treatment area).

(14) In the balloon-type electrode catheter of (13) above, it is preferable that the length of the tip region of the cylindrical portion is 1 to 3 mm.

A balloon-type electrode catheter having such a configuration can more effectively prevent the vascular area in contact with the distal cone portion and the surrounding tissue from being cauterized, and can perform cauterization treatment over the entire cylindrical portion, including the distal region.

(15) In the balloon-type electrode catheters of (9) to (14) above, it is preferable that the surface electrode is formed to extend along the axial direction of the balloon and consists of a plurality of band-shaped electrodes arranged at equal angular intervals along the circumferential direction of the balloon, and that the base end of each of the band-shaped electrodes is fixed to the outer peripheral surface of the metal ring, thereby electrically connecting each of the band-shaped electrodes to the metal ring.

With a balloon-type electrode catheter configured in this manner, each of the multiple band-shaped electrodes formed at equal angular intervals along the circumferential direction of the balloon can be electrically connected to the current-carrying connector via a metal ring and a conductor, allowing high-frequency current to be passed evenly through each of the multiple band-shaped electrodes, thereby enabling uniform cauterization treatment of a blood vessel or the tissue surrounding it along the circumferential direction of the vessel.

The balloon-type electrode catheter of the present invention allows the cylindrical portion of the balloon expansion section to perform cauterization treatment on the blood vessel or the diseased tissue surrounding it, while preventing the blood vessel section or the surrounding tissue in contact with the cone portion of the expansion section from being cauterized.

1 is a plan view of a balloon-type electrode catheter according to a first embodiment of the present invention. FIG. FIG. 2 is a partially cutaway front view of the balloon electrode catheter shown in FIG. 1 (a front view including a cross section taken along line II-II in FIG. 1). FIG. 2 is a perspective view showing the tip portion of the balloon-type electrode catheter shown in FIG. 1. FIG. 2 is a front view showing a schematic diagram of the tip portion of the balloon-type electrode catheter shown in FIG. 1. FIG. 2 is a perspective view showing the distal end portion (the distal end side of the balloon) of the balloon-type electrode catheter shown in FIG. 1 . FIG. 2 is a perspective view showing the distal end portion (the proximal end side of the balloon) of the balloon-type electrode catheter shown in FIG. 1 . FIG. 3 is a partial enlarged view (detailed view of portion VI) of FIG. 2 . FIG. 7 is a partially enlarged view (detailed view of part VII) of FIG. 6 . FIG. 3 is a partial enlarged view (detailed view of portion VIII) of FIG. 2 . IX-IX cross-sectional view of FIG. FIG. 10 is a partial enlarged view (detailed view of part X) of FIG. 9 . 1. This is a cross-sectional view taken along the line XI-XI in FIG. This is a cross-sectional view taken along line XII-XII of FIG. FIG. 13 is a partial enlarged view (detailed view of portion XIII) of FIG. 12 . This is a cross-sectional view taken along line XIV-XIV of Figure 1. 1 is a cross-sectional view taken along the line XV-XV of FIG. FIG. 16 is a partial enlarged view (detailed view of part XVI) of FIG. 15 . 1. This is a cross-sectional view taken along the line XVII-XVII of FIG. FIG. 18 is a partial enlarged view (detailed view of portion XVIII) of FIG. 17 . This is a cross-sectional view taken along line XIX-XIX in Figure 1. FIG. 20 is a partial enlarged view (detailed view of part XX) of FIG. 19 . This is a cross-sectional view taken along the line XXI-XXI in FIG. FIG. 22 is a partially enlarged view (detailed view of part XXII) of FIG. 21 . This is a cross-sectional view taken along line XXIII-XXIII of Figure 1. This is a cross-sectional view taken along line XXIV-XXIV of Figure 1. FIG. 11 is a front view showing a schematic diagram of a tip portion of a balloon-type electrode catheter according to a second embodiment of the present invention. FIG. 11 is a front view showing a schematic diagram of a tip portion of a balloon-type electrode catheter according to a third embodiment of the present invention. FIG. 13 is a front view showing a schematic diagram of a tip portion of a balloon-type electrode catheter according to a fourth embodiment of the present invention.

First Embodiment
The balloon-type electrode catheter 100 of this embodiment is a balloon-type electrode catheter that is introduced intravascularly and is used to treat lesion tissue, such as a tumor, in or around a blood vessel by high-frequency ablation.

The balloon-type electrode catheter 100 shown in FIGS. 1 to 24 comprises an outer tube 10 consisting of a circular tubular portion 11 and a semicircular tubular portion 13, and having a central lumen 10L and sub-lumens 101L to 112L arranged around the central lumen 10L; an electrical connector 21 arranged on the base end side of the outer tube 10; an expandable and contractible expansion section 31 consisting of a distal cone portion 313, a cylindrical portion 311 and a proximal cone portion 315; and neck portions (distal neck portion 33 and proximal neck portion 35) continuous with both ends of the expansion section 31, the proximal neck portion 35 being fixed to the circular tubular portion 11 constituting the distal end of the outer tube 10, and the expansion section 31 being fixed to the distal end of the outer tube 10. a balloon 30 connected to the distal end side of the outer tube 10 by containing therein a semicircular tubular portion 13 constituting the balloon 30; an inner tube 41 having a guidewire lumen, inserted into a central lumen 10L of the outer tube 10, extending from an opening of the central lumen 10L into the interior of the balloon 30 and extending inside the balloon 30; a distal tip 46 having a lumen (guidewire lumen) communicating with the guidewire lumen of the inner tube 41, connected to the distal end of the inner tube 41 inside the balloon 30, and fixed to a distal neck portion 33 and extending outside the balloon 30; , strip electrodes 51 to 54 (surface electrodes) made of a thin metal film formed on the outer surface of the distal cone portion 313 and the cylindrical portion 311 of the expansion portion 31; a metal ring 60 attached to the distal neck portion 33 of the balloon 30 and electrically connected to each of the strip electrodes 51 to 54 by having the distal end of each of the strip electrodes 51 to 54 fixed to the outer circumferential surface; a lead wire 70 having its distal end connected to the inner circumferential surface of the metal ring 60, extending into the interior of the balloon 30 and into the sub-lumen 112L of the outer tube 10 (the cylindrical portion 11), and having its proximal end connected to the electrical connector 21; and a temperature sensor (thermocouple) 80 extending into the tube wall of the side neck portion 35 and the lumen 106L of the outer tube 10 (circular tubular portion 11) and having its base end connected to the electrical connector 21; the outer peripheral surface of the metal ring 60, the electrode portions of the strip electrodes 51-54 fixed to the outer peripheral surface of the metal ring 60, the electrode portions of the strip electrodes 51-54 formed on the outer surface of the distal neck portion 33, the electrode portions of the strip electrodes 51-54 formed on the outer surface of the distal cone portion 313 of the extension portion 31, and the electrode portions of the strip electrodes 51-54 formed on the outer surface of the distal region 3113 of the cylindrical portion 311 are insulated and coated with a resin layer 65.
In Figures 1 and 2, reference numeral 20 denotes a Y connector connected to the base end side of the outer tube 10, 22 denotes a fluid supply connector, 23 denotes a fluid discharge connector, 24 denotes a guidewire connector, 26 denotes a conductor protection tube, 27 denotes a fluid supply tube, and 28 denotes a fluid discharge tube.

As shown in FIGS. 3A, 4, 5, 14, 15, and 17 to 22, the outer tube 10 constituting the balloon type electrode catheter 100 is composed of a circular tubular portion 11 and a semicircular tubular portion 13.
The base end and a part of the tip end of the outer tube 10 are constituted by a circular tubular portion 11 , and the tip end of the outer tube 10 (excluding the part) is constituted by a semicircular tubular portion 13 .

As shown in Figures 17, 19 and 21, inside the circular tubular portion 11 of the outer tube 10, a central lumen 10L and twelve sub-lumens 101L to 112L arranged around it at equal angular intervals (30°) are formed.
In the cylindrical portion 11 , each of the sub-lumens 101 L to 112 L is formed by a lumen tube surrounding it, and these lumen tubes are fixed by the binder resin that forms the cylindrical portion 11 .

As shown in FIGS. 14 and 15, inside the semicircular tubular portion 13 of the outer tube 10, sub-lumens 101L to 105L are formed continuously from the inside of the circular tubular portion 11.
The lumen tubes surrounding each of the sub-lumens 101 L to 105 L in the semicircular tubular portion 13 are fixed by a binder resin that forms the semicircular tubular portion 13 .

As shown in Figures 3A and 4, the sublumens 101L to 105L arranged inside the circular tubular portion 11 and inside the semicircular tubular portion 13 each open at the tip surface 14 of the semicircular tubular portion 13, which is the tip surface of the outer tube 10.

Each of the sub-lumens 101L to 105L communicates with the fluid supply connector 22 shown in FIGS.
As a result, sublumens 101L to 105L (five of the twelve sublumens formed in the outer tube 10) become "fluid supply sublumens" for supplying fluid to the inside of the balloon 30 (expansion portion 31).
An example of the fluid supplied to the inside of the balloon 30 is physiological saline.

As shown in FIGS. 3A and 5, the central lumen 10L and the sub-lumens 106L to 112L formed inside the cylindrical portion 11 each open at the distal end surface 12 of the cylindrical portion 11.
However, the openings of the sublumens 106L, 110L and 112L are sealed by a seal material 90 shown in FIG.

Each of the sub-lumens 107L to 111L communicates with the fluid discharge connector 23 shown in FIG.
As a result, sublumens 107L to 109L and 111L (four of the twelve sublumens formed in the outer tube 10) become "fluid discharge sublumens" for discharging the fluid supplied to the inside of the balloon 30 (expansion section 31) from the inside of the balloon 30.

The material from which the outer tube 10 is made is not particularly limited, but examples of the material include polyamide-based resins such as polyamide, polyether polyamide, polyether block amide (PEBAX (registered trademark)) and nylon, of which PEBAX is preferred.

The outer diameter of the outer tube 10 (the outer diameter at the base end portion described below) is normally 1.0 to 3.3 mm, and a preferred example is 1.45 mm.
The diameter of the central lumen 10L of the outer tube 10 is usually set to 0.35 to 0.95 mm, and a preferred example is 0.85 mm.
The diameter of the sub-lumens 101L to 112L of the outer tube 10 is usually set to 0.10 to 0.75 mm, and a suitable example is 0.25 mm.
The length of the outer tube 10 is normally set to 100 to 2200 mm, and a suitable example is 1800 mm.

As shown in FIGS. 1 and 2 , a Y connector 20 is connected to the base end of the outer tube 10 .
As shown in FIG. 23, the lumen tube surrounding the sub-lumens 101L to 105L and the sub-lumens 107L to 111L of the outer tube 10 advances into the inside of the Y connector 20 from the proximal end of the outer tube 10.

As shown in FIG. 24, the proximal end of the lumen tube surrounding the sub-lumens 101L to 105L (fluid supply sub-lumens) is connected (fixed with adhesive 95) to a fluid supply tube 27 having a single lumen structure inside the Y connector 20.
This fluid supply tube 27 extends to the outside of the Y connector 20 , and the base end of the fluid supply tube 27 is connected to the fluid supply connector 22 .

The proximal end of the lumen tube surrounding the sub-lumens 107L to 111L is connected (fixed with adhesive 95) inside the Y connector 20 to a fluid discharge tube 28 having a single lumen structure.
This fluid discharge tube 28 extends to the outside of Y connector 20 , and the base end of fluid discharge tube 28 is connected to fluid discharge connector 23 .

The balloon 30 constituting the balloon-type electrode catheter 100 is composed of an expansion section 31 that expands and contracts, a tip-side neck section 33 that is continuous with the tip of the expansion section 31 (tip-side cone section 313), and a base-side neck section 35 that is continuous with the base end of the expansion section 31 (base-side cone section 315).

The expansion portion 31 of the balloon 30 is a space-forming portion that expands when a fluid is supplied thereto and contracts when the fluid is discharged therefrom.
As shown in Figures 1 to 5, the expansion portion 31 of the balloon 30 consists of a cylindrical portion 311, a distal cone portion 313 extending from the tip of the cylindrical portion 311 to the proximal end of the distal neck portion 33, and a proximal cone portion 315 extending from the proximal end of the cylindrical portion 311 to the tip of the proximal neck portion 35.

The base-end neck portion 35 is fixed to the tip portion of the outer tube 10 (tip portion formed by the circular tubular portion 11), and the expansion portion 31 contains the tip portion of the outer tube 10 (tip portion formed by the semicircular tubular portion 13), so that the balloon 30 is connected to the tip side of the outer tube 10.

Here, the tip portion of the outer tube 10 (the circular tubular portion 11 shown in FIG. 19) to which the base-end neck portion 35 of the balloon 30 is fixed has its surface portion chipped off, and its outer diameter is smaller than the outer diameter of the base end portion of the outer tube 10 (the circular tubular portion 11 shown in FIG. 21) to which the base-end neck portion 35 is not fixed.
21. The outside diameter of the base end neck portion 35 shown in FIG. 19 is substantially equal to the outside diameter of the base end portion of the outer tube 10 shown in FIG.

This makes it possible to prevent the base-end neck portion 35 from impairing the insertability of a sheath or endoscope used to introduce the balloon electrode catheter 100 into the lumen.
Furthermore, since the outer diameter of the outer tube 10 can be set to the maximum diameter limited by the sheath or endoscope (there is no need to consider expansion of the outer diameter due to the thickness of the base-end neck portion), the diameter of the sub-lumens 101L to 112L of the outer tube 10 can be sufficiently secured, and the cooling effect inside the balloon 30 can be further improved.

As shown in Figures 3A and 4, the distal end surface 14 of the semicircular tubular portion 13 into which the fluid supply sub-lumens 101L to 105L open is located near the distal end of the cylindrical portion 311, which is distal to the axial middle position of the expansion portion 31 of the balloon 30.
As a result, the fluid flowing through the fluid supply sublumens 101L to 105L is discharged toward the tip from each opening located near the tip of the cylindrical portion 311, and the discharged fluid can reach the vicinity of the tip of the expansion portion 31 (tip cone portion 313), thereby forming a flow of fluid from the tip side to the base end side inside the balloon 30 (expansion portion 31).

If the opening position of the fluid supply sublumen is located on the base end side of the axial midpoint of the expansion section of the balloon, even if fluid is ejected from the opening toward the tip end after the balloon is expanded, the fluid cannot reach the vicinity of the tip of the expansion section, and a flow of fluid from the tip end to the base end cannot be formed inside the balloon.

As shown in Figures 3A and 5, the distal end surface 12 of the tubular portion 11 into which the fluid discharge sublumens 107L-109L and 111L open is located at the base end of the expansion portion 31.

The material of which the balloon 30 is made is not particularly limited, and the same materials as those used to make up balloons in conventionally known balloon catheters can be used, such as polyamide-based resins such as polyamide, polyether polyamide, PEBAX, and nylon; polyurethane-based resins such as thermoplastic polyether urethane, polyether polyurethane urea, fluoropolyether urethane urea, polyether polyurethane urea resin, and polyether polyurethane urea amide.

The diameter of the balloon 30 (expansion portion 31) is usually set to 0.7 to 30.0 mm, and a preferred example is 2.0 mm.
The outside diameter of the base end neck portion 35 of the balloon 30 is substantially equal to the outside diameter of the base end portion of the outer tube 10, and is usually 1.0 to 3.3 mm, with a preferred example being 1.45 mm.
The length of the expansion portion 31 of the balloon 30 is usually 11 to 70 mm, and a suitable example is 30 mm.
The length of the cylindrical portion 311 of the expansion portion 31 is usually set to 5 to 50 mm, and a suitable example is set to 20 mm.
The length of the distal cone portion 313 and the proximal cone portion 315 of the expansion portion 31 is usually 3 to 10 mm, and a suitable example is 5 mm.

In the balloon electrode catheter 100 of this embodiment, the inner tube 41 and the distal tip 46 form an inner shaft.
The inner tube 41 that constitutes the balloon-type electrode catheter 100 has a lumen (guidewire lumen) through which a guidewire can be inserted, and is inserted into the central lumen 10L of the outer tube 10 (circular tubular portion 11), with its tip extending from the opening of the central lumen 10L into the inside of the balloon 30 (expansion portion 31).

The tip of the inner tube 41 extending into the balloon 30 (expansion section 31) extends into the base end cone section 315, cylindrical section 311 and tip end cone section 313 of the expansion section 31, with half of its outer circumferential surface covered by the semicircular tubular section 13, and is connected to the tip tip 46 inside the tip end cone section 313.

On the other hand, as shown in Figures 23 and 24, the base end of the inner tube 41 enters the inside of the Y connector 20 from the base end of the outer tube 10 (the opening on the base end side of the central lumen 10L), extends through the inside of the Y connector 20, and extends to the outside of the Y connector 20, and the base end of the inner tube 41 is connected to the guidewire connector 24.

The material constituting the inner tube 41 may be the same as that used for the inner tubes constituting conventional balloon catheters, but PEEK resin (polyether ether ketone resin), a crystalline thermoplastic resin with excellent mechanical properties, is preferred.

The outer diameter of the inner tube 41 is the same as or slightly smaller than the diameter of the central lumen 10L of the outer tube 10 through which it is inserted, and is usually 0.34 to 0.99 mm, with a preferred example being 0.84 mm.
The inner diameter of the inner tube 41 is usually set to 0.31 to 0.92 mm, and a preferred example is 0.68 mm.

The distal tip 46 constituting the balloon electrode catheter 100 has a lumen (guidewire lumen) that communicates with the guidewire lumen of the inner tube 41, and is connected to the distal end of the inner tube 41 inside the distal cone portion 313 of the expansion section 31 of the balloon 30, and is fixed to the distal neck portion 33 and extends to the outside of the balloon 30. The distal end of the distal tip 46 is open.

The material of which the tip tip 46 is made is not particularly limited, but may include, for example, polyamide, polyether polyamide, polyamide-based resins such as PEBAX and nylon, polyurethane, etc.

The inner diameter of the tip 46 is substantially the same as the inner diameter of the inner tube 41, and is usually 0.
The thickness is set to 0.31 to 0.92 mm, and a preferred example is 0.68 mm.
The outer diameter of the distal tip 46 is usually set to 0.35 to 2.6 mm, and a suitable example is set to 1.0 mm.
The outer diameter of the distal neck portion 33 of the balloon 30 to which the distal tip 46 is fixed is usually 0.37 to 3.3 mm, and a preferred example is 1.18 mm.

As shown in Figures 3A, 3B, 4 to 7, and 9 to 15, strip electrodes 51 to 54 formed from a thin metal film extending along the axial direction of the balloon 30 are arranged at 90° intervals along the circumferential direction of the balloon 30 as surface electrodes through which high-frequency current is passed, on the outer surface of the balloon 30 (the distal neck portion 33, the distal cone portion 313 of the expansion portion 31, and the cylindrical portion 311).

Examples of materials for the metal thin films that form the strip electrodes 51 to 54 include gold, platinum, silver, copper, alloys of these metals, and stainless steel.
The metal thin film constituting the strip electrodes 51 to 54 preferably has a thickness of 0.5 to 5.0 μm, and more preferably 1.0 to 2.5 μm.
If this film thickness is too small, there is a risk that the metal thin film will reach a high temperature due to Joule heat during the procedure (while high frequency current is being applied).
On the other hand, if the thin film is too thick, it will be difficult for the metal thin film to follow the changes in shape of the balloon that accompany expansion and contraction, which may impair the expansion and contraction properties of the balloon.

The method for forming the thin metal film that constitutes the strip electrodes 51 to 54 on the outer surface of the balloon 30 is not particularly limited, and conventional methods for forming thin metal films, such as vapor deposition, sputtering, plating, and printing, can be used.

As shown in Figures 3A, 3B, 4, 6, 9 and 10, a metal ring 60 is attached to the distal neck portion 33 of the balloon 30. The metal ring 60 constituting the balloon electrode catheter 100 is fixed to the distal neck portion 33 by crimping. The distal end of each of the band electrodes 51-54 is fixed (contacted) to the outer circumferential surface of this metal ring 60. This electrically connects each of the band electrodes 51-54 to the metal ring 60.

Examples of materials for the metal ring 60 include platinum or a platinum-based alloy.

The inner diameter of the metal ring 60 attached to the distal neck portion 33 is substantially the same as the outer diameter of the distal neck portion 33 and is usually 0.37 to 3.3 mm, with a preferred example being 1.18 mm.
The outer diameter of the metal ring 60 attached to the distal neck portion 33 is smaller than the outer diameters of the outer tube 10 and the proximal neck portion 35, and is usually 0.98 to 3.28 mm, with a preferred example being 1.32 mm.

As shown in Figures 3A, 3B, 4, 6, 7, and 9 to 13, the outer peripheral surface of the metal ring 60 (excluding the surface region to which the strip electrodes 51 to 54 are fixed), the electrode portions of the strip electrodes 51 to 54 fixed to the outer peripheral surface of the metal ring 60, the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the tip neck portion 33, the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the tip cone portion 313 of the extension portion 31, and the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the tip region 3113 of the cylindrical portion 311 are insulated and coated with a resin layer 65 (shown by dots in Figures 3A and 4).

Since the electrode portions formed on the outer surface of the tip neck portion 33 and the tip cone portion 313 of the extension portion 31 are insulated, even when electricity is passed through each of the band electrodes 51 to 54, the electrode portions fixed to the outer peripheral surface of the metal ring 60, the electrode portions formed on the outer surface of the tip neck portion 33, and the vicinity of the electrode portions formed on the outer surface of the tip cone portion 313 of the extension portion 31 do not become hot.

Furthermore, in this balloon-type electrode catheter 100, the electrode portion formed on the outer surface of the tip region 3113 of the cylindrical portion 311 is insulated, so that the tip cone portion 313 can be prevented from rising in temperature due to heat conduction from the tip region 3113.
This prevents the distal neck portion 33 and the distal cone portion 313 of the expansion portion 31 from reaching the cauterization temperature, thereby preventing the vascular area in contact with the distal neck portion 33 and the distal cone portion 313 and the surrounding tissue from being cauterized.

In addition, by appropriately adjusting the length of the tip region 3113 (the region where the resin layer 65 is formed in the cylindrical portion 311), it is possible to heat the tip region 3113 by heat conduction from the region of the cylindrical portion 311 other than the tip region 3113 (the region where the electrode portion is not insulated), and perform cauterization treatment of the vascular site in contact with this tip region 3113 or the tissue surrounding it (the entire cylindrical portion 311 can be used as the cauterization treatment region).

The length of the tip region 3113 of the cylindrical portion 311 forming the resin layer 65 is usually set to 1 to 3 mm, and a suitable example is set to 2 mm.
By making the length of the tip region 3113 1 mm or more (by insulating and coating the electrode portions of each of the strip electrodes 51 to 54 formed in the tip region 3113 with a resin layer 65), it is possible to prevent the tip cone portion 313 from becoming hot due to thermal conduction, even if high-frequency current is passed through each of the strip electrodes 51 to 54.

In addition, by making the length of the tip region 3113 3 mm or less, the tip region 3113 can be heated to a temperature at which it can be cauterized, and cauterization treatment can be performed over the entire cylindrical portion 311, including the tip region 3113.

An example of a manner in which the outer peripheral surface of the metal ring 60 and each of the electrode portions of the strip electrodes 51 to 54 are insulated is to form a resin layer 65 on the outer surface of the tip neck portion 33, the tip cone portion 313, and the outer surface of the tip region 3113 of the cylindrical portion 311 so as to cover the metal ring 60 and each of the electrode portions of the strip electrodes 51 to 54.

The resin constituting the resin layer 65 is not particularly limited as long as it is an insulating resin with good adhesion to the balloon 30. For example, the resins exemplified as the constituent materials of the balloon 30 can be used, and among these, polyurethane-based resins are preferred.

The method of forming the resin layer 65 is not particularly limited, but an example of such a method is to apply the resin for forming the resin layer to the area to be insulated by spraying or the like, and then dry and harden the coating.

The tip of a conducting wire 70 is fixed to the inner peripheral surface of the metal ring 60 .
As shown in Figures 9 and 11, this conductor 70 extends within the tube wall of tip tip 46, and as shown in Figures 12, 14 and 15, it extends along inner tube 41 into the interior of expansion portion 31 of balloon 30, and as shown in Figures 17, 19 and 21, it extends into sublumen 112L of outer tube 10 (circular tubular portion 11), and as shown in Figures 23 and 24, it extends into the interior of Y connector 20 and extends from Y connector 20 through the interior of conductor protection tube 26 extending from Y connector 20.

The base end of the conductor 70 is connected to an electrical connector 21. This electrical connector 21 functions both as an electrical connector for passing high-frequency current through each of the strip electrodes 51 to 54 and as a thermocouple connector for connecting the temperature sensor 80 to a temperature measuring device.

By connecting each of the strip electrodes 51-54 to the electrical connector 21 via the metal ring 60 and the conductor 70, high-frequency current can be passed evenly through each of the strip electrodes 51-54.

Examples of materials that can be used for the conductor 70 include copper, silver, gold, platinum, tungsten, and alloys of these metals, and it is preferable that the conductor 70 is provided with an electrically insulating protective coating such as a fluororesin.

As shown in Figures 3, 5, and 15 to 20, a temperature sensor 80 consisting of a thermocouple is embedded in the tube wall of the balloon 30. The side temperature portion 81 (temperature measuring junction) of this temperature sensor 80 is located in the tube wall of the expansion portion 31.

As shown in Figures 19 to 22, the temperature sensor 80 enters the sub-lumen 106L of the outer tube 10 (circular tubular portion 11) from the tube wall of the base-end neck portion 35 of the balloon 30 and extends into the sub-lumen 106L, and as shown in Figures 23 and 24, together with the conductor 70, extends into the interior of the Y connector 20 and extends from the Y connector 20 through the interior of the conductor protection tube 26 extending from the Y connector 20.
The proximal end of the temperature sensor 80 is connected to the electrical connector 21 .

According to the balloon-type electrode catheter 100 of this embodiment, the cylindrical portion 311 of the expansion portion 31 of the balloon 30 can perform cauterization treatment on a blood vessel or the lesion tissue surrounding it.
In addition, since the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the distal neck portion 33 and the distal cone portion 313 of the extension portion 31 are insulated and coated with a resin layer 65, the vicinity of these electrode portions does not become hot during cauterization treatment.
Furthermore, since the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the tip region 3113 of the cylindrical portion 311 are insulated, the tip cone portion 313 can be prevented from rising in temperature due to heat conduction from the tip region 3113.
This makes it possible to prevent the vascular site in contact with the distal neck portion 33 and the distal cone portion 313 of the expansion portion 31 and the surrounding tissue from being cauterized, thereby making it possible to prevent (restenosis) of the vascular site.

In addition, since the metal ring 60 is attached to the distal neck portion of the balloon 30 and the distal end of each of the band electrodes 51 to 54 is fixed to the outer peripheral surface of the metal ring 60, each of the band electrodes 51 to 54 is electrically connected to the electrical connector 21 via the metal ring 60 and the conductor 70, so that high-frequency current can be passed evenly through each of the band electrodes 51 to 54, thereby enabling the cauterization treatment of the blood vessel or the diseased tissue around it to be performed uniformly along the circumferential direction of the blood vessel.

In addition, since the outer diameter of the metal ring 60 attached to the tip neck portion 33 of the balloon 30 is smaller than the outer diameter of the outer tube 10 and the base neck portion 35, the metal ring 60 will not get caught in the opening of the sheath or endoscope used during introduction, and the insertability of the balloon electrode catheter 100 into the lumen of the sheath or endoscope will not be impaired.

Furthermore, each of the fluid supply sub-lumens 101L to 105L opens at the tip surface 14 of the semicircular tubular portion 13 located near the tip of the cylindrical portion 311 of the expansion portion 31 of the balloon 30, and each of the fluid discharge sub-lumens 107L to 109L and 111L opens at the tip surface 12 of the circular tubular portion 11 located at the base end of the expansion portion 31 of the balloon 30. Therefore, even after the balloon 30 is expanded (after the interior is filled with fluid), a flow of fluid can be formed from the tip side to the base end side inside the balloon 30, and the fluid can be circulated.

In particular, the fluid ejected in the distal direction from the openings of the fluid supply sublumens 101L-105L hits the inner wall surface of the distal cone portion 313 of the expansion section 31, and then flows in the proximal direction along the inner wall surfaces of the cylindrical portion 311 and the proximal cone portion 315 of the expansion section 31, thereby circulating the fluid inside the balloon 30 (expansion section 31).

As a result, the inside of the balloon 30 can be efficiently cooled throughout the entire expansion section 31, thereby sufficiently cooling the tissue surrounding the band electrodes 51-54 and reliably preventing fibrosis of the tissue.

In addition, there are five fluid supply sub-lumens 101L to 105L arranged in the outer tube 10, and four fluid discharge sub-lumens 107L to 109L and 111L, so that the inside of the balloon 30 can be maintained at a constant pressure (expansion pressure).

Examples of cases in which the balloon-type electrode catheter 100 of this embodiment can be used include tumors in or around blood vessels and the vagus nerve, and more specifically, bile duct cancer, lung cancer, liver cancer, kidney cancer, adrenal adenoma, and the renal artery vagus nerve.

Second Embodiment
In the balloon electrode catheter 200 of this embodiment having the tip portion shown in Fig. 25, similarly to the first embodiment, the outer peripheral surface of the metal ring 60, the electrode portions of the band electrodes 51 to 54 fixed to the outer peripheral surface of the metal ring 60, the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the tip neck portion 33, the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the tip cone portion 313 of the expansion section 31, and the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the tip region 3113 of the cylindrical portion 311 are insulated and coated with a resin layer 65. Note that the band electrode 54 arranged opposite the band electrode 52 is not shown in Fig. 25.

The balloon-type electrode catheter 200 of this embodiment differs from the electrode catheter 100 of the first embodiment in that the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the base end region 3115 of the cylindrical portion 311 are insulated and coated with a resin layer 66.

An example of a method for insulating and coating the electrode portions of each of the strip electrodes 51 to 54 formed on the outer surface of the base end region 3115 of the cylindrical portion 311 is to form a resin layer 66 on the outer surface of the base end region 3115 so as to cover these electrode portions.

The resin constituting the resin layer 66 may be the same as the resin constituting the resin layer 65. The method for forming the resin layer 66 may be the same as the method for forming the resin layer 65.

The length of the base end region 3115 of the cylindrical portion 311 forming the resin layer 66 is usually set to 1 to 3 mm, and a suitable example is set to 2 mm.
By making the length of the base end region 3115 1 mm or more (by insulating and coating the electrode portions of each of the strip electrodes 51 to 54 formed in the base end region 3115 with a resin layer 66), it is possible to prevent the base end cone portion 315 from becoming hot due to thermal conduction, even if high frequency current is passed through each of the strip electrodes 51 to 54.
Furthermore, by making the length of the base end region 3115 3 mm or less, the base end region 3115 can be heated to a temperature at which it can be cauterized by thermal conduction from areas of the cylindrical portion 311 other than the base end region 3115 (areas where the electrode portion is not insulated), and cauterization treatment can be performed over the entire area of the cylindrical portion 3111 including the base end region 3115.
The band-shaped electrodes 51 to 54 constituting the balloon electrode catheter 200 of this embodiment are formed up to the base end position of the cylindrical portion 311 (the same applies to the balloon electrode catheter 100 of the first embodiment).
With this configuration, for example, when the balloon 30 is extended from the forceps port of the endoscope, the base end positions of the band electrodes 51 to 54 can be determined from the image captured by the endoscope, thereby making it possible to determine the base end of the cylindrical portion 311 (i.e., the base end position of the portion that can be subjected to cauterization treatment).

The balloon electrode catheter 200 of the present embodiment can achieve the same effects as those achieved by the balloon electrode catheter 100 of the first embodiment.
Furthermore, since the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the base end region 3115 of the cylindrical portion 311 of the expansion section 31 are insulated and coated with the resin layer 66, the base end cone portion 315 can be prevented from rising in temperature due to heat conduction from the base end region 3115 during cauterization treatment, thereby preventing the vascular site in contact with the base end cone portion 315 and the surrounding tissue from being cauterized.
In addition, by appropriately adjusting the length of the base end region 3115, the base end region 3115 can be heated by thermal conduction from areas of the cylindrical portion 311 other than the base end region 3115, and the vascular site in contact with the base end region 3115 or the tissue surrounding it can be cauterized (the entire cylindrical portion 311 can be the cauterization treatment area).

Third Embodiment
The balloon electrode catheter 300 of this embodiment having a distal end portion shown in FIG. 26 comprises an outer tube 10, an electrical connector arranged on the proximal end side of the outer tube 10, a balloon 30, an inner tube, a distal tip 46, band electrodes 51 to 54, a metal ring 60 which is attached to the proximal neck portion 35 of the balloon 30 and electrically connected to each of the band electrodes 51 to 54 by having the proximal end of each of the band electrodes 51 to 54 fixed to the outer peripheral surface thereof, and a distal end connected to the inner peripheral surface of the metal ring 60 and a proximal end connected to the electrical connector. The metal ring 60 is provided with a lead wire connected to an electrical connector and a temperature sensor, and the outer peripheral surface of the metal ring 60, the electrode portions of the strip electrodes 51 to 54 fixed to the outer peripheral surface of the metal ring 60, the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the base-end neck portion 35, the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the base-end cone portion 315 of the extension portion 31, and the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the base-end region 3115 of the cylindrical portion 311 are insulated and coated with a resin layer 67.

In the balloon electrode catheter 300, the electrical connector, inner tube, conductor, and temperature sensor not shown in Fig. 26 are similar to the electrical connector 21, inner tube 41, conductor 70, and temperature sensor 80 constituting the balloon electrode catheter 100 of the first embodiment. In Fig. 26, the band electrode 54 arranged opposite the band electrode 52 is not shown.

The balloon electrode catheter 300 of this embodiment differs from the balloon electrode catheter 100 of the first embodiment in that the metal ring 60 constituting the balloon electrode catheter 300 is attached to the proximal neck portion 35 of the balloon 30. As a result, the band electrodes 51 to 54 have their respective proximal ends fixed to the outer circumferential surface of the metal ring 60, and are formed on the outer surfaces of the proximal neck portion 35 of the balloon 30, the proximal cone portion 315 of the expansion portion 31, and the cylindrical portion 311.
5. The electrode portions formed on the outer surfaces of the base end cone portion 315 of the expansion portion 31 and the base end region 3115 of the cylindrical portion 311 are insulated.

An example of a manner of insulating and coating the electrode portions of each of the band electrodes 51 to 54 formed on the outer surface of the base-end neck portion 35, the base-end cone portion 315 of the expansion portion 31, and the base-end region 3115 of the cylindrical portion 311 is to form a resin layer 67 on the outer surface of the base-end neck portion 35, the base-end cone portion 315, and the outer surface of the base-end region 3115 of the cylindrical portion 311 so as to cover these electrode portions.

The resin constituting the resin layer 67 may be the same as the resin constituting the resin layer 65. The method for forming the resin layer 67 may be the same as the method for forming the resin layer 65.

The length of the base end region 3115 of the cylindrical portion 311 forming the resin layer 67 is usually set to 1 to 3 mm, and a suitable example is set to 2 mm.
By making the length of the base end region 3115 1 mm or more (by insulating and coating the electrode portions of each of the strip electrodes 51 to 54 formed in the base end region 3115 with a resin layer 67), it is possible to prevent the base end cone portion 315 from becoming hot due to thermal conduction, even if high frequency current is passed through each of the strip electrodes 51 to 54.
Furthermore, by making the length of the base end region 3115 3 mm or less, the base end region 3115 can be heated to a temperature at which it can be cauterized by thermal conduction from areas of the cylindrical portion 311 other than the base end region 3115 (areas where the electrode portion is not insulated), and cauterization treatment can be performed over the entire area of the cylindrical portion 3111 including the base end region 3115.

According to the balloon-type electrode catheter 300 of this embodiment, the cylindrical portion 311 of the expansion portion 31 of the balloon 30 can perform cauterization treatment on a blood vessel or the lesion tissue surrounding it.
In addition, since the electrode portions of each of the band electrodes 51 to 54 formed on the outer surface of the base-end neck portion 35 and the base-end cone portion 315 of the expansion portion 31 are insulated and coated with a resin layer 67, the vicinity of these electrode portions does not become hot during cauterization treatment.
Furthermore, since the electrode portions of the strip electrodes 51 to 54 formed on the outer surface of the base end region 3115 of the cylindrical portion 311 are insulated, the base end cone portion 315 can be prevented from rising in temperature due to thermal conduction from the base end region 3115.
This prevents the vascular site and the surrounding tissue in contact with the base-end neck portion 35 and the base-end cone portion 315 of the expansion portion 31 from being cauterized, thereby preventing (restenosis) of the vascular site.

Fourth Embodiment
In the balloon electrode catheter 400 of this embodiment having the tip portion shown in Fig. 27, similarly to the third embodiment, the outer peripheral surface of the metal ring 60, the electrode portions of the band electrodes 51 to 54 fixed to the outer peripheral surface of the metal ring 60, the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the base-end neck portion 35, the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the base-end cone portion 315 of the expansion section 31, and the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the base-end region 3115 of the cylindrical portion 311 are insulated and coated with a resin layer 67. Note that the band electrode 54 arranged opposite the band electrode 52 is not shown in Fig. 27.

The balloon-type electrode catheter 400 of this embodiment differs from the electrode catheter 300 of the third embodiment in that the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the tip region 3113 of the cylindrical portion 311 are insulated and coated with a resin layer 68.

An example of a method for insulating and coating the electrode portions of each of the strip electrodes 51 to 54 formed on the outer surface of the tip region 3113 of the cylindrical portion 311 is to form a resin layer 68 on the outer surface of the tip region 3113 of the cylindrical portion 311 so as to cover these electrode portions.

The resin constituting the resin layer 68 may be the same as the resin constituting the resin layer 65. The method for forming the resin layer 68 may be the same as the method for forming the resin layer 65.

The length of the tip region 3113 of the cylindrical portion 311 forming the resin layer 68 is usually set to 1 to 3 mm, and a suitable example is set to 2 mm.
By making the length of the tip region 3113 1 mm or more (by insulating and coating the electrode portions of each of the strip electrodes 51 to 54 formed in the tip region 3113 with a resin layer 68), it is possible to prevent the tip cone portion 313 from becoming hot due to thermal conduction, even if high-frequency current is passed through each of the strip electrodes 51 to 54.
Furthermore, by making the length of the tip region 3113 3 mm or less, the tip region 3113 can be heated to a temperature at which it can be cauterized by thermal conduction from areas of the cylindrical portion 311 other than the tip region 3113 (areas where the electrode portion is not insulated), and cauterization treatment can be performed over the entire cylindrical portion 311 including the tip region 3113.

The balloon electrode catheter 400 of this embodiment can achieve the same effects as those achieved by the balloon electrode catheter 300 of the third embodiment.
Furthermore, since the electrode portions of the band electrodes 51 to 54 formed on the outer surface of the tip region 3113 of the cylindrical portion 311 of the extension section 31 are insulated and coated with a resin layer 68, the tip cone portion 313 can be prevented from heating up due to heat conduction from the tip region 3113 during cauterization treatment, thereby preventing the vascular site in contact with the tip cone portion 313 and the surrounding tissue from being cauterized.
In addition, by appropriately adjusting the length of the tip region 3113, the tip region 3113 can be heated by thermal conduction from areas of the cylindrical portion 311 other than the tip region 3113, and the vascular site in contact with the tip region 3113 or the tissue surrounding it can be cauterized (the entire cylindrical portion 311 can be the cauterization treatment area).

100 Balloon type electrode catheter 10 Outer tube 10L Central lumen 101L to 105L Sub-lumen (sub-lumen for fluid supply)
107L to 109L, 111L sub-lumen (sub-lumen for discharging fluid)
106L, 110L, 112L Sub-lumen 11 Circular tubular portion 12 Distal surface of circular tubular portion 13 Semicircular tubular portion 14 Distal surface of semicircular tubular portion 20 Y connector 21 Electrical connector 22 Fluid supply connector 23 Fluid discharge connector 24 Guidewire connector 26 Conductor protection tube 27 Fluid supply tube 28 Fluid discharge tube 30 Balloon 31 Expansion portion 311 Cylindrical portion 3113 Distal region of cylindrical portion 3115 Base end region of cylindrical portion 313 Distal cone portion 315 Base end cone portion 33 Distal neck portion 35 Base end neck portion 41 Inner tube 46 Distal tip 51 to 54 Band-shaped electrode (surface electrode)
60 Metal ring 65 Resin layer 70 Conductive wire 80 Temperature sensor (thermocouple)
81 Temperature measuring part of temperature sensor 90 Sealing material 95 Adhesive 200 Balloon type electrode catheter 66 Resin layer 300 Balloon type electrode catheter 67 Resin layer 400 Balloon type electrode catheter 68 Resin layer

Claims (7)

A balloon-type electrode catheter that is introduced intravascularly and used for cauterizing a blood vessel or tissue surrounding the blood vessel,
an outer tube having a central lumen and a plurality of sub-lumens disposed around the central lumen;
an electrical connector disposed on a base end side of the outer tube;
a balloon having an expansion section consisting of a distal cone section, a cylindrical section, and a proximal cone section, and neck sections continuous with both ends of the expansion section, the proximal neck section being fixed to the distal end of the outer tube, thereby being connected to the distal end side of the outer tube;
an inner tube having a lumen through which a guide wire can be inserted, the inner tube being inserted into the central lumen of the outer tube, extending from an opening of the central lumen into the balloon, and extending through the balloon;
a distal tip having a lumen communicating with the lumen of the inner tube, connected to a distal end of the inner tube inside the balloon, and fixed to the neck portion on the distal end side and extending to the outside of the balloon;
A metal ring attached to the neck portion on the base end side;
a surface electrode electrically connected to the metal ring and made of a thin metal film formed on the neck portion at the base end , the cone portion at the base end of the extension portion, and the outer surface of the cylindrical portion;
a conductive wire having a tip fixed to an inner circumferential surface of the metal ring, extending into the interior of the balloon and into any one of the sub-lumens of the outer tube, and having a base end fixed to the current-carrying connector, thereby electrically connecting the surface electrode and the current-carrying connector;
a balloon electrode catheter having an electrode portion formed on the outer surface of the base end side cone portion and having an insulating coating thereon; 2. The balloon electrode catheter according to claim 1, wherein the electrode portions formed on the outer surfaces of the base-end neck portion, the base-end cone portion of the expansion portion, and the base- end region of the cylindrical portion are insulated. 3. The balloon electrode catheter according to claim 2 , wherein the length of the base end region of the cylindrical portion is 1 to 3 mm. 4. The balloon electrode catheter according to claim 2 , wherein the metal ring is coated with an insulating material. The surface electrode is formed up to a tip position of the cylindrical portion,
5. The balloon electrode catheter according to claim 2 , wherein the electrode portion formed on the outer surface of the tip region of the cylindrical portion is insulated. 6. The balloon electrode catheter according to claim 5 , wherein the length of the tip region of the cylindrical portion is 1 to 3 mm. 7. The balloon electrode catheter according to claim 1, wherein the surface electrode is formed to extend along the axial direction of the balloon and is composed of a plurality of band-shaped electrodes arranged at equal angular intervals along the circumferential direction of the balloon, and a base end of each of the band-shaped electrodes is fixed to the outer peripheral surface of the metal ring, thereby electrically connecting each of the band-shaped electrodes to the metal ring .

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