Balloon Catheter

Abstract

An object of the present invention is to provide a balloon-type electrode catheter that can be introduced through a vessel without impairing the insertability into a sheath or an inner lumen of an endoscope and that can perform a cauterization treatment on a lesion tissue over a wide range. The balloon-type electrode catheter of the present invention comprises: an outer tube (10); a connector for conducting electricity (21); a balloon (30) having necks (33) and (35) at both ends of the expansion portion (31); an inner tube (41); a top end tip (46); strip electrodes (51) to (54) formed on the outer surface of the balloon (30); a metal ring (60) attached to the top end side neck (31) and having the top ends of the strip electrodes (51) to (54) fixedly connected to its outer peripheral surface; and a guide wire (70) having its top end fixed to the inner peripheral surface of the metal ring (60) and its base end fixed to the connector for conducting electricity (21), thereby electrically connecting each strip electrode (51) to (54) and the connector for conducting electricity (21).

Description

Technical Field

[0001] The present invention relates to a balloon-type electrode catheter, and more particularly to a balloon-type electrode catheter for use in high-frequency cauterization treatment of a vessel or tissues surrounding the vessel by introduction through the vessel. Background Art

[0002] As a balloon-type electrode catheter (intravascular ablation device) for performing high-frequency cauterization treatment on blood vessels or the tissues surrounding them, there has been previously introduced a balloon-type electrode catheter comprising an outer tube (catheter shaft), a balloon connected to the top end of the outer tube, an inner tube (guide wire lumen) inserted through the cavity of the outer tube and the inside of the balloon, a lumen (supply lumen) inserted through the cavity of the outer tube for supplying fluid to the inside of the balloon, a lumen (return lumen) inserted through the cavity of the outer tube for discharging the fluid supplied to the inside of the balloon, and a surface electrode (high-frequency electrode) provided on the outer surface of the balloon (see Patent Document 1 below).

[0003] The balloon constituting the balloon electrode catheter described in Patent Document 1 has an expansion portion that expands and contracts and necks formed at both ends thereof, wherein the base end neck is fixed to the outer tube and the tip end neck is fixed to the inner tube (guidewire lumen).

[0004] According to the balloon electrode catheter described in Patent Document 1, high-frequency current is passed through the surface electrode provided on the outer surface of the balloon, thereby enabling high-frequency cauterization treatment to be performed on the blood vessel or the lesion tissue around it.

[0005] Furthermore, the interior of the balloon can be cooled by causing the fluid supplied from the lumen (supply lumen) to circulate inside the balloon and then be discharged from the lumen (return lumen).

[0006] On the other hand, as a method for passing a high-frequency current to a surface electrode formed on the outer surface of a balloon in a balloon electrode catheter for electrically isolating the pulmonary vein, the inventors have proposed a method in which a metal ring is attached to the neck of the balloon fixed to the top end of the catheter shaft (the neck on the base end side where a connector for conducting electricity is located), the surface electrode is electrically connected to the metal ring, and the metal ring is electrically connected to the connector for conducting electricity via a wire (see Patent Document 2 listed below).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application No. 2013-532564

[0010] Patent Document 2: Japanese Patent Application Publication No. 2016-185296 (particularly Figure 4 ) Summary of the invention

[0011] Problems to be solved by the invention

[0012] As a method of passing high-frequency current to a surface electrode formed on the outer surface of a balloon in a balloon electrode catheter used for high-frequency cauterization treatment of blood vessels or the tissues surrounding them as described in Patent Document 1, a method as described in Patent Document 2 can be considered, in which a metal ring is attached to the neck (neck on the base end side) of the balloon fixed to the outer tube (catheter shaft) and current is passed through the metal ring.

[0013] However, in order to enclose an inner tube (guide wire lumen) for inserting a guide wire and lumens (supply lumen and return lumen) for circulating a cooling fluid in the lumen of an outer tube constituting a balloon electrode catheter as described in Patent Document 1, the outer diameter of the outer tube is quite large.

[0014] In particular, when performing ablative treatment of tumors or the like using a balloon-type electrode catheter, in order to enhance the cooling effect of the tissue surrounding the surface electrode, it is necessary to increase the flow rate of the fluid circulating inside the balloon. Therefore, it is required to increase the diameter of the lumen through which the cooling fluid circulates, and accordingly, it is also necessary to further increase the outer diameter of the outer tube.

[0015] Then, when the base end neck of the balloon is fixed by an outer tube with a large outer diameter and a metal ring is attached to the base end neck, the outer diameter of the metal ring will significantly exceed the outer diameter (shaft diameter or wrapping diameter) limited by the sheath and endoscope used when introducing the electrode catheter. When the balloon-type electrode catheter is introduced, the metal ring will be stuck in the opening of the sheath and endoscope used, making it impossible for the balloon-type electrode catheter to be inserted into these cavities.

[0016] The present invention has been accomplished based on the above-described circumstances.

[0017] An object of the present invention is to provide a balloon-type electrode catheter that can be introduced through a blood vessel without impairing the insertability into the lumen of a sheath or endoscope used and that can perform a cauterization treatment on a blood vessel or a lesion tissue around the blood vessel over a wide range.

[0018] Another object of the present invention is to provide a balloon-type electrode catheter capable of performing homogeneous cauterization treatment on a vessel or tissues surrounding the vessel along the circumferential direction of the vessel.

[0019] Still another object of the present invention is to provide a balloon-type electrode catheter that has an excellent cooling effect not only on the inside of the balloon but also on the tissue surrounding the surface electrode.

[0020] Technical Solution

[0021] (1) The balloon-type electrode catheter of the present invention is a balloon-type electrode catheter for use in high-frequency cauterization treatment of a blood vessel or tissues surrounding the blood vessel, and is characterized by comprising:

[0022] An outer tube having a central cavity and a plurality of secondary cavities arranged around the central cavity;

[0023] A power supply connector, arranged on the base end side of the outer tube;

[0024] The balloon has an expansion portion that expands and contracts and a neck portion that is continuous with both ends thereof, wherein the neck portion at the base end is fixed to the top end portion of the outer tube, whereby the balloon is connected to the top end side of the outer tube;

[0025] The inner tube has a lumen through which a guide wire can be inserted, is inserted into the central lumen of the outer tube, extends from the opening of the central lumen toward the interior of the balloon, and extends inside the balloon;

[0026] A top tip having a cavity communicating with the cavity of the inner tube, connected to the top of the inner tube inside the balloon, and fixed to the top side neck and extending to the outside of the balloon;

[0027] A surface electrode, which is composed of a metal film formed on the outer surface of the balloon at the expansion portion and the top side neck portion;

[0028] a metal ring, attached to the top side neck of the balloon, the top end of the surface electrode being fixedly connected to the outer peripheral surface of the metal ring, whereby the metal ring is electrically connected to the surface electrode; and

[0029] The guide wire has its tip fixed to the inner peripheral surface of the metal ring, extends into the sub-lumen of either the balloon or the outer tube, and its base end is fixed to the power supply connector, thereby electrically connecting the surface electrode to the power supply connector.

[0030] According to the balloon electrode catheter having such a configuration, the surface electrode formed on the outer surface of the balloon can be electrically connected to the current supply connector via the metal ring and the guide wire, so that a high-frequency current can be reliably supplied to the surface electrode.

[0031] This makes it possible to perform cauterization treatment on a blood vessel or the lesion tissue around it over a wide area.

[0032] In addition, the top side neck of the balloon for the metal ring to be attached is the neck fixed to the top tip, and its outer diameter is much smaller than the base side neck fixed to the outer tube. Therefore, the outer diameter of the metal ring attached to the top side neck can be smaller than the outer diameters of the outer tube and the base side neck.

[0033] Therefore, when the balloon electrode catheter is introduced, the metal ring will not be caught in the opening of the sheath or endoscope used, and the insertability of the balloon electrode catheter into the inner cavity of the sheath or endoscope will not be impaired.

[0034] (2) In the balloon-type electrode catheter of the present invention, preferably, the surface electrode is a plurality of strip electrodes formed in a manner extending along the axial direction of the balloon and arranged at equal angles along the circumferential direction of the balloon, and each top end portion of the strip electrodes is fixed to the outer peripheral surface of the metal ring.

[0035] According to the balloon-type electrode catheter with such a structure, each of the multiple strip electrodes formed at equal angles along the circumferential direction of the balloon can be electrically connected to the power supply connector through the metal ring and the wire. Therefore, the high-frequency current can flow evenly to each of the multiple strip electrodes, thereby enabling homogeneous cauterization treatment of the blood vessel or the tissue around it along the circumferential direction of the blood vessel.

[0036] (3) In the balloon electrode catheter of the present invention, it is preferable that the metal ring is covered with insulation.

[0037] According to the balloon electrode catheter having such a configuration, the metal ring can be prevented from reaching a high temperature when current is applied, and the normal tissue around the metal ring can be prevented from being burned.

[0038] (4) In the balloon electrode catheter of the present invention, preferably, at least one of the sub-lumens of the outer tube is a fluid supply sub-lumen for supplying a fluid to the inside of the balloon and for allowing the fluid to flow.

[0039] At least one of the sub-lumens included in the outer tube is a fluid discharge sub-lumen through which the fluid supplied to the interior of the balloon flows in order to discharge the fluid from the interior of the balloon.

[0040] (5) In the balloon-type electrode catheter of (4) above, preferably, the dilation portion of the balloon contains the distal end portion of the outer tube fixed to the base end side neck portion of the balloon,

[0041] The opening of the fluid supply sub-cavity is located on the tip side relative to the axial middle position of the expansion portion.

[0042] The opening of the fluid discharge sub-lumen is located at or near the base end of the expansion portion.

[0043] According to the balloon-type electrode catheter with such a structure, the fluid supply port to the interior of the balloon and the fluid discharge port from the interior of the balloon are axially displaced relative to each other, thereby, even after the balloon is expanded (filled with fluid inside), a flow of fluid from the top end side to the base end side can be formed and the fluid can flow inside the balloon, thereby not only fully cooling the interior of the balloon but also fully cooling the tissue around the surface electrode.

[0044] (6) In the balloon electrode catheter of (4) and (5) above, preferably, the number of the sub-lumens for fluid supply is greater than the number of the sub-lumens for fluid discharge.

[0045] According to the balloon electrode catheter having the above-described structure, the interior of the balloon can be maintained at a constant pressure (expansion pressure).

[0046] (7) In the balloon electrode catheter of the present invention, it is preferred that the outer diameter of the distal end portion of the outer tube to which the proximal end neck portion of the balloon is fixed is formed to be smaller than the outer diameter of the proximal end portion of the outer tube.

[0047] The outer diameter of the proximal end neck portion of the balloon is substantially equal to the outer diameter of the proximal end portion of the outer tube.

[0048] According to the balloon electrode catheter of such a configuration, the outer diameter of the proximal neck portion having the largest outer diameter is substantially equal to the outer diameter of the proximal end portion of the outer tube, so that the proximal neck portion does not hinder the insertability into the inner cavity of the sheath or the endoscope.

[0049] Furthermore, the outer diameter of the outer tube can be set to the maximum diameter limited by the sheath and the endoscope, so that the diameters of the fluid supply and fluid discharge sub-lumens of the outer tube can be sufficiently ensured, and the cooling effect inside the balloon can be further improved.

[0050] (8) In the balloon electrode catheter of the present invention, preferably, a temperature sensor is disposed on the tube wall of the balloon.

[0051] Effects of the Invention

[0052] According to the present invention, the balloon electrode catheter can be introduced through a blood vessel without impairing the insertability into the lumen of a sheath or endoscope used, and can perform cauterization treatment on a blood vessel or a lesion tissue around it over a wide range.

[0053] Furthermore, according to the balloon electrode catheter of the present invention including the surface electrode composed of a plurality of strip-shaped electrodes, it is possible to perform a homogeneous cauterization treatment on the blood vessel or the tissue around the blood vessel along the circumferential direction of the blood vessel.

[0054] Moreover, the balloon-type electrode catheter of the present invention having an outer tube with a sub-lumen for fluid supply and a sub-lumen for fluid discharge has an excellent cooling effect not only on the inside of the balloon but also on the tissue surrounding the surface electrode, compared with conventional balloon-type electrode catheters, wherein the sub-lumen for fluid supply opens at the top end side relative to the axial middle position of the expansion portion of the balloon, and the sub-lumen for fluid discharge opens at the base end of the expansion portion of the balloon or in the vicinity thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a top view of a balloon electrode catheter according to one embodiment of the present invention.

[0056] Figure 2 yes Figure 1 The partial cross-sectional front view of the balloon electrode catheter shown (including Figure 1 (front view of section II-II).

[0057] Figure 3 Yes means Figure 1 A perspective view of the tip portion of a balloon electrode catheter is shown.

[0058] Figure 4 Yes means Figure 1 A perspective view of the tip portion (tip side of the balloon) of a balloon-type electrode catheter is shown.

[0059] Figure 5 Yes means Figure 1 A perspective view of the distal end portion (the proximal end side of the balloon) of the balloon-type electrode catheter shown.

[0060] Figure 6 yes Figure 2 A partial enlarged view (detailed view of Part VI).

[0061] Figure 7 yes Figure 6 A partial enlarged view (detailed view of Part VII).

[0062] Figure 8 yes Figure 2 A partial enlarged view (detailed view of Part VIII).

[0063] Fig. 9 yes Figure 1 IX-IX sectional view.

[0064] Fig.10 yes Fig. 9 A partial enlarged view (detailed view of part X).

[0065] Fig.11 yes Figure 1 XI-XI sectional view.

[0066] Fig.12 yes Figure 1 XII-XII sectional view.

[0067] Fig.13 yes Fig.12 A partial enlarged view (detailed view of Part XIII).

[0068] Fig.14 yes Figure 1 XIV-XIV section view.

[0069] Fig.15 yes Figure 1 XV-XV sectional view.

[0070] Fig.16 yes Fig.15 A partial enlarged view (detailed view of Part XVI).

[0071] Fig.17 yes Figure 1 XVII-XVII sectional view.

[0072] Fig.18 yes Fig.17 A partial enlarged view (detailed view of Part XVIII).

[0073] Fig.19 yes Figure 1 XIX-XIX sectional view.

[0074] Fig. 20 yes Fig.19 A local enlarged view (detailed view of part XX).

[0075] Fig.21 yes Figure 1 XXI-XXI sectional view.

[0076] Fig. 22 yes Fig.21 A partial enlarged view (detailed view of Part XXII).

[0077] Fig.23 yes Figure 1 XXIII-XXIII sectional view.

[0078] Fig.24 yes Figure 1 XXIV-XXIV sectional view. DETAILED DESCRIPTION

[0079] <Implementation Method>

[0080] The balloon-type electrode catheter 100 of this embodiment is a balloon-type electrode catheter that is introduced through a blood vessel and is used to treat a diseased tissue such as a tumor in or around a blood vessel by high-frequency cauterization.

[0081] Figure 1 to Figure 24 The balloon-type electrode catheter 100 shown in the figure comprises: an outer tube 10, which is composed of a circular tubular portion 11 and a semicircular tubular portion 13, and has a central cavity 10L and sub-cavities 101L to 112L arranged around it; an electrical connector 21, which is arranged on the base end side of the outer tube 10; a balloon 30, which has an expansion portion 31 for expansion and contraction and a neck portion (a top end neck portion 33 and a base end neck portion 35) continuous with both ends thereof, and the base end neck portion 35 is fixed to the top end of the outer tube 10. The expansion part 31 includes a semi-circular tubular part 13 constituting the top end of the outer tube 10, thereby connecting the balloon 30 to the top end side of the outer tube 10; the inner tube 41 has a guide wire cavity and is inserted into the central cavity 10L of the outer tube 10, extending from the opening of the central cavity 10L to the inside of the balloon 30, and extending inside the balloon 30; the top end tip 46 has a cavity (guide wire cavity) connected to the guide wire cavity of the inner tube 41, and is connected to the inner end of the balloon 30. The top end of the tube 41 is connected and fixed to the top side neck 33 and extends to the outside of the balloon 30; the strip electrodes 51-54 (surface electrodes) are composed of a metal film formed on the outer surface of the expansion part 31 and the top side neck 33 of the balloon 30; the metal ring 60 is attached to the top side neck 33 of the balloon 30, and the top ends of the strip electrodes 51-54 are fixedly connected to its outer peripheral surface, thereby being electrically connected to each strip electrode 51-54; the wire 70, the top of which is connected to the top of the balloon 30. The end is connected to the inner circumferential surface of the metal ring 60, extends to the sub-cavity 112L inside the balloon 30 and the outer tube 10 (tubular part 11), and its base end is connected to the electrical connector 21; and a temperature sensor (thermocouple) 80, whose top end (temperature measuring part 81) is buried in the tube wall of the expansion part 31 of the balloon 30, extends to the tube wall of the expansion part 31 and the base side neck 35 and the cavity 106L of the outer tube 10 (tubular part 11), and its base end is connected to the electrical connector 21.

[0082] exist Figure 1 and Figure 2 20 is a Y connector connected to the base end side of the outer tube 10, 22 is a fluid supply connector, 23 is a fluid discharge connector, 24 is a guide wire connector, 26 is a wire protection tube, 27 is a fluid supply tube, and 28 is a fluid discharge tube.

[0083] like Figure 3 to Figure 5 , Fig.14 , Fig.15 , Figure 17 to Figure 22 As shown, the outer tube 10 constituting the balloon electrode catheter 100 is composed of a circular tubular portion 11 and a semicircular tubular portion 13 .

[0084] The base end portion and a part of the distal end portion of the outer tube 10 are constituted by a circular tubular portion 11 , and the distal end portion (except for the part) of the outer tube 10 is constituted by a semicircular tubular portion 13 .

[0085] like Fig.17 , Fig.19 as well as Fig.21 As shown, a central cavity 10L and twelve sub-cavities 101L to 112L arranged at equal angles (30°) around the central cavity 10L are formed inside the circular tubular portion 11 of the outer tube 10 .

[0086] In the circular tubular portion 11 , each of the sub-cavities 101L to 112L is formed by a lumen surrounding the circular tubular portion 11 , and these lumen are fixed by an adhesive resin forming the circular tubular portion 11 .

[0087] like Fig.14 and Fig.15 As shown, 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 .

[0088] The lumen tubes surrounding the respective sub-lumens 101L to 105L in the semicircular tubular portion 13 are fixed by the adhesive resin forming the semicircular tubular portion 13 .

[0089] like Figure 3 and Figure 4 As shown, the sub-lumens 101L to 105L arranged inside the circular tubular portion 11 and inside the semicircular tubular portion 13 are respectively opened at the distal end surface 14 of the semicircular tubular portion 13 which is the distal end surface of the outer tube 10 .

[0090] Each sub-cavity 101L-105L and Figure 1 and Figure 2 The fluid supply is shown connected to a connector 22 .

[0091] Thus, the sub-lumens 101L to 105L (five sub-lumens among the twelve sub-lumens formed in the outer tube 10 ) serve as “sub-lumens for fluid supply” for supplying fluid to the inside of the balloon 30 (expansion section 31 ).

[0092] Here, as the fluid supplied into the balloon 30 , physiological saline can be exemplified.

[0093] like Figure 3 and Figure 5 As shown, the central cavity 10L and the sub-cavities 106L to 112L formed inside the circular tubular portion 11 are opened at the top end surface 12 of the circular tubular portion 11 .

[0094] The openings of the sub-cavity 106L, the sub-cavity 110L and the sub-cavity 112L are Fig.17 The seal 90 shown seals.

[0095] Each sub-cavity 107L-111L and Figure 1 The fluid drain is shown connected with connector 23.

[0096] Thus, the sub-lumens 107L to 109L and the sub-lumen 111L (four of the twelve sub-lumens formed in the outer tube 10 ) serve as “sub-lumens for fluid discharge” for discharging the fluid supplied to the interior of the balloon 30 (expansion section 31 ) from the interior of the balloon 30 .

[0097] The material constituting the outer tube 10 is not particularly limited, and examples thereof include polyamide-based resins such as polyamide, polyether polyamide, polyether block amide copolymer (PEBAX (registered trademark)), and nylon. Among these, PEBAX is preferred.

[0098] The outer diameter of the outer tube 10 (the outer diameter of the base end portion described later) is usually set to 1.0 mm to 3.3 mm, and is set to 1.45 mm as a preferred example.

[0099] The diameter of the central lumen 10L of the outer tube 10 is usually set to 0.35 mm to 0.95 mm, and is set to 0.85 mm as a preferred example.

[0100] The diameter of the sub-lumens 101L to 112L of the outer tube 10 is usually set to 0.10 mm to 0.75 mm, and is set to 0.25 mm as a preferred example.

[0101] The length of the outer tube 10 is usually set to 100 mm to 2200 mm, and is set to 1800 mm as a preferred example.

[0102] like Figure 1 and Figure 2 As shown, a Y connector 20 is connected to the proximal end side of the outer tube 10 .

[0103] like Fig.23 As shown, the lumen tubes surrounding the sub-lumens 101L to 105L and the sub-lumens 107L to 111L of the outer tube 10 enter into the interior of the Y connector 20 from the proximal end of the outer tube 10 .

[0104] like Fig.24 As shown, the base end of the lumen tube surrounding the sub-lumens 101L to 105L (sub-lumens for fluid supply) is connected to the fluid supply tube 27 of the single lumen structure inside the Y connector 20 (fixed by an adhesive 95).

[0105] The 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 .

[0106] The proximal end portion of the lumen surrounding the sub-lumens 107L to 111L is connected to the fluid discharge tube 28 of a single lumen structure inside the Y connector 20 (fixed by an adhesive 95 ).

[0107] The fluid discharge tube 28 extends to the outside of the Y connector 20 , and the base end of the fluid discharge tube 28 is connected to the fluid discharge connector 23 .

[0108] The balloon 30 constituting the balloon electrode catheter 100 includes a dilation portion 31 that expands and contracts, a distal neck portion 33 continuous with the distal end of the dilation portion 31 , and a proximal neck portion 35 continuous with the proximal end of the dilation portion 31 .

[0109] The expansion portion 31 of the balloon 30 is a space-forming portion that expands by supplying a fluid into the interior thereof and contracts by discharging the fluid from the interior thereof.

[0110] like Figure 1 to Figure 5 As shown, the expansion portion 31 of the balloon 30 is composed of a cylindrical portion 311, a top end side tapered portion 313 from the top end of the cylindrical portion 311 to the base end of the top end side neck 33, and a base end side tapered portion 315 from the base end of the cylindrical portion 311 to the top end of the base end side neck 35.

[0111] A base end neck 35 is fixed to the top end portion of the outer tube 10 (the top end portion formed by the circular tubular portion 11 ), and the expansion portion 31 wraps around the top end portion of the outer tube 10 (the top end portion formed by the semicircular tubular portion 13 ), thereby connecting the balloon 30 to the top end side of the outer tube 10 .

[0112] Here, the distal end portion ( Fig.19 As for the circular tubular portion 11 shown in the figure, the outer diameter of the outer tube 10 without the base end neck 35 fixed thereto is smaller than that of the base end portion ( Fig.21 The circular tubular portion 11) shown has a small outer diameter.

[0113] also, Fig.19 The outer diameter of the base end side neck 35 is shown Fig.21 The outer diameters of the base end portions of the outer tubes 10 shown are substantially the same.

[0114] This prevents the insertability of a sheath or an endoscope for introducing the balloon electrode catheter 100 into the inner cavity from being impaired by the proximal neck portion 35 .

[0115] In addition, the outer diameter of the outer tube 10 can be set to the maximum diameter limited by the sheath and the endoscope (without considering the expansion of the outer diameter caused by the thickness of the base end side neck), so that the diameter of the sub-lumen 101L~112L of the outer tube 10 can be fully ensured, and the cooling effect inside the balloon 30 can be further improved.

[0116] like Figure 3 and Figure 4As shown, the distal end surface 14 of the semicircular tubular portion 13 where the fluid supply sub-lumens 101L to 105L open is located near the distal end of the cylindrical portion 311 which is closer to the distal end than the axial middle position of the expansion portion 31 of the balloon 30 .

[0117] As a result, the fluid flowing in the fluid supply sub-cavities 101L~105L is ejected toward the top end direction from the openings located near the top end of the cylindrical portion 311, and the ejected fluid can reach the top end of the expansion portion 31 (the top end side conical portion 313), thereby forming a flow of fluid from the top end side to the base end side inside the balloon 30 (expansion portion 31).

[0118] In a case where the opening position of the sub-cavity for fluid supply is closer to the base end side than the axial middle position of the expansion portion of the balloon, even if the fluid is ejected from the opening toward the top end after the balloon is expanded, the fluid cannot reach the vicinity of the top end of the expansion portion, and a flow of fluid from the top end side to the base end side cannot be formed inside the balloon.

[0119] like Figure 3 and Figure 5 As shown, the distal end surface 12 of the circular tubular portion 11 , into which the fluid discharge sub-cavities 107L to 109L and the fluid discharge sub-cavity 111L open, is located at the proximal end of the expansion portion 31 .

[0120] There is no particular limitation on the material constituting the balloon 30, and the same material as that constituting the balloon of the existing known balloon catheter can be used, for example, polyamide, polyether polyamide, polyamide resins such as PEBAX and nylon, thermoplastic polyether polyurethane, polyether polyurethane urea, fluoropolyether polyurethane urea, polyether polyurethane urea resin and polyether polyurethane urea amide and other polyurethane resins.

[0121] The diameter of the balloon 30 (dilation portion 31 ) is usually set to 0.7 mm to 30.0 mm, and is set to 2.0 mm as a preferred example.

[0122] The outer diameter of the proximal neck portion 35 of the balloon 30 is substantially equal to the outer diameter of the proximal end portion of the outer tube 10 , and is usually set to 1.0 mm to 3.3 mm, and is set to 1.45 mm as a preferred example.

[0123] The length of the balloon 30 (expansion portion 31 ) is usually set to 8 mm to 50 mm, and is set to 20 mm as a preferred example.

[0124] In the balloon electrode catheter 100 of the present embodiment, the inner tube 41 and the distal tip 46 constitute an inner axis.

[0125] The inner tube 41 constituting the balloon 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 ), and its top end extends from the opening of the central lumen 10L into the interior of the balloon 30 (expansion portion 31 ).

[0126] The top end portion of the inner tube 41 extending into the interior of the balloon 30 (expansion portion 31) is covered by the semi-circular portion 13 on half of its outer circumference, and extends inside the base end side conical portion 315, the cylindrical portion 311 and the top end side conical portion 313 of the expansion portion 31, and is connected to the top end tip 46 inside the top end side conical portion 313.

[0127] On the other hand, Fig.23 and Fig.24 As shown, the base end portion of the inner tube 41 enters into the interior of the Y connector 20 from the base end of the outer tube 10 (the opening on the base end side of the central cavity 10L), extends inside the Y connector 20, and extends to the outside of the Y connector 20. The base end of the inner tube 41 is connected to the guide wire connector 24.

[0128] As a constituent material of the inner tube 41 , the same material as that constituting the inner tube of a conventionally known balloon catheter can be used, but PEEK resin (polyetheretherketone resin) which is a crystalline thermoplastic resin having excellent mechanical properties is preferable.

[0129] 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 the inner tube 41 is inserted, and is usually 0.34 mm to 0.99 mm, and is 0.84 mm as a preferred example.

[0130] The inner diameter of the inner tube 41 is usually set to 0.31 mm to 0.92 mm, and is set to 0.68 mm as a preferred example.

[0131] The top tip 46 constituting the balloon electrode catheter 100 has a lumen (guidewire lumen) communicating with the guidewire lumen of the inner tube 41, is connected to the top end of the inner tube 41 inside the top end tapered portion 313 of the expansion portion 31 of the balloon 30, and is fixed to the top end neck portion 33 and extends to the outside of the balloon 30. The top end of the top tip 46 is open.

[0132] The material constituting the distal tip 46 is not particularly limited, and examples thereof include polyamide, polyether polyamide, PEBAX, polyamide-based resins such as nylon, and polyurethane.

[0133] The inner diameter of the distal tip 46 is substantially the same as the inner diameter of the inner tube 41 and is usually set to 0.31 mm to 0.92 mm, and is set to 0.68 mm as a preferred example.

[0134] The outer diameter of the distal tip 46 is usually set to 0.35 mm to 2.6 mm, and is set to 1.0 mm as a preferred example.

[0135] The outer diameter of the distal end side neck portion 33 of the balloon 30 to which the distal end tip 46 is fixed is generally set to 0.37 mm to 3.3 mm, and is 1.18 mm as a preferred example.

[0136] like Figure 3 to Figure 7 and Figures 9 to 15 As shown, on the outer surface of the balloon 30 (the cylindrical portion 311 of the expansion portion 31, the top conical portion 313 and the top neck portion 33), strip electrodes 51 to 54 are arranged at 90° intervals along the circumferential direction of the balloon 30 as surface electrodes for passing high-frequency current. The strip electrodes 51 to 54 are formed by a metal film in a manner extending along the axial direction of the balloon 30.

[0137] Examples of the constituent material of the metal thin film constituting the strip-shaped electrodes 51 to 54 include gold, platinum, silver, copper, alloys thereof, stainless steel, and the like.

[0138] The thickness of the metal thin film constituting the strip-shaped electrodes 51 to 54 is preferably 0.5 μm to 5.0 μm, and more preferably 1.0 μm to 2.5 μm.

[0139] If the film thickness is too small, the metal thin film may become hot due to Joule heat during operation (during high-frequency energization).

[0140] On the other hand, when the film thickness of the thin film is too large, it may become difficult for the metal thin film to follow the shape change of the balloon accompanying the expansion and contraction, and the expandability and contraction properties of the balloon may be impaired.

[0141] The method for forming the metal thin film constituting the strip-shaped electrodes 51 to 54 on the outer surface of the balloon 30 is not particularly limited, and a common metal thin film forming method such as vapor deposition, sputtering, plating, or printing can be used.

[0142] like Figure 3 , Figure 4 , Figure 6 , Fig. 9 as well as Fig.10 As shown, a metal ring 60 is attached to the top neck portion 33 of the balloon 30. The metal ring 60 constituting the balloon electrode catheter 100 is fixed to the top neck portion 33 by riveting. The top ends of the strip electrodes 51 to 54 are fixed (contacted) to the outer peripheral surface of the metal ring 60. Thus, the strip electrodes 51 to 54 are electrically connected to the metal ring 60.

[0143] As a constituent material of the metal ring 60, platinum or a platinum-based alloy can be cited. Fig. 9As shown, the metal ring 60 is made of a resin material 65 (in Figure 3 and Figure 4 Thus, the metal ring 60 can be prevented from reaching a high temperature when energized, and the normal tissue around the metal ring 60 can be prevented from being burned.

[0144] 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 set to 0.37 mm to 3.3 mm, and is set to 1.18 mm as a preferred example.

[0145] 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 set to 0.98 mm to 3.28 mm, and is set to 1.32 mm as a preferred example.

[0146] The tip of the lead wire 70 is fixed to the inner peripheral surface of the metal ring 60 .

[0147] like Fig. 9 and Fig.11 As shown, the wire 70 extends within the wall of the top tip 46. Fig.12 , Fig.14 as well as Fig.15 As shown, the guide wire 70 extends along the inner tube 41 inside the expansion portion 31 of the balloon 30. Fig.17 , Fig.19 as well as Fig.21 As shown, the guide wire 70 extends in the sub-lumen 112L of the outer tube 10 (the cylindrical portion 11). Fig.23 and Fig.24 As shown, the wire 70 extends inside the Y connector 20 , passes through the inside of the wire protection tube 26 extending from the Y connector 20 , and extends out from the Y connector 20 .

[0148] The base end of the lead wire 70 is connected to the electric connector 21. The electric connector 21 has both the function of a current supply connector for passing a high frequency current through each of the strip electrodes 51 to 54 and the function of a thermocouple connector for connecting the temperature sensor 80 to a temperature measuring device.

[0149] The strip-shaped electrodes 51 to 54 are connected to the electric connector 21 via the metal ring 60 and the conductive wire 70 , thereby allowing a high-frequency current to flow evenly through the strip-shaped electrodes 51 to 54 .

[0150] Examples of the material of the lead wire 70 include copper, silver, gold, platinum, tungsten, and alloys of these metals. The lead wire 70 is preferably provided with an electrically insulating protective coating such as a fluororesin.

[0151] like Figure 3 , Figure 5 , Figures 15 to 20As shown in FIG. 1 , a temperature sensor 80 composed of a thermocouple is embedded in the tube wall of the balloon 30 . A side temperature portion 81 (temperature measurement junction) of the temperature sensor 80 is located in the tube wall of the expansion portion 31 .

[0152] like Figure 19 to Figure 22 As shown, the temperature sensor 80 enters the sub-cavity 106L of the outer tube 10 (the circular tubular portion 11) from the tube wall of the base end side neck 35 of the balloon 30 and extends along the sub-cavity 106L, as shown in FIG. Fig.23 and Fig.24 As shown, the temperature sensor 80 and the wire 70 extend inside the Y connector 20 , pass through the inside of the wire protection tube 26 extending from the Y connector 20 , and extend out from the Y connector 20 .

[0153] The base end of the temperature sensor 80 is connected to the electric connector 21 .

[0154] According to the balloon electrode catheter 100 of the present embodiment, the band-shaped electrodes 51 to 54 formed on the outer surface of the balloon 30 can perform high-frequency cauterization treatment over a wide range on a blood vessel or a lesion around it.

[0155] In addition, the metal ring 60 is attached to the top side neck of the balloon 30 and the top ends of the strip electrodes 51 to 54 are fixed to the outer peripheral surface of the metal ring 60. Each strip electrode 51 to 54 is electrically connected to the electrical connector 21 through the metal ring 60 and the wire 70. Therefore, high-frequency current can flow evenly to each strip electrode 51 to 54, thereby uniformly cauterizing the blood vessel or the diseased tissue around it along the circumferential direction of the blood vessel.

[0156] In addition, the outer diameter of the metal ring 60 attached to the top side neck 33 of the balloon 30 is smaller than the outer diameter of the outer tube 10 and the base side neck 35. Therefore, the metal ring 60 will not be stuck in the opening of the sheath or endoscope used during introduction, and the insertability of the balloon-type electrode catheter 100 into the inner cavity of the sheath or endoscope will not be impaired.

[0157] In addition, each sub-cavity 101L~105L for fluid supply opens at the top end surface 14 of the semi-circular tubular portion 13 near the top end of the cylindrical portion 311 of the expansion portion 31 of the balloon 30, and each sub-cavity 107L~109L for fluid discharge and the sub-cavity 111L for fluid discharge open at the top end surface 12 of the tubular portion 11 at the base end of the expansion portion 31 of the balloon 30. Thus, even after the balloon 30 is expanded (filled with fluid inside), a flow of fluid from the top end side to the base end side can be formed inside the balloon 30, thereby enabling the fluid to flow.

[0158] In particular, the fluid ejected toward the top end direction from the opening of the fluid supply sub-cavity 101L~105L hits the inner wall surface of the top end side tapered portion 313 of the expansion portion 31, and then flows toward the base end direction along the inner wall surface of the cylindrical portion 311 and the base end side tapered portion 315 of the expansion portion 31, thereby enabling the fluid to circulate inside the balloon 30 (expansion portion 31).

[0159] As a result, the interior of the balloon 30 can be efficiently cooled over the entire region of the expansion portion 31 , thereby sufficiently cooling the tissue around the band-shaped electrodes 51 to 54 , and reliably preventing the tissue from being fibrotic.

[0160] Furthermore, the outer tube 10 is provided with five fluid supply sub-lumens 101L to 105L 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).

[0161] Diseases to which the balloon electrode catheter 100 of this embodiment can be applied include tumors of blood vessels or their peripheries, vagus nerves, and the like. Specifically, cholangiocarcinoma, lung cancer, liver cancer, kidney cancer, adrenal adenoma, and renal artery vagus nerves can be cited.

[0162] As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment, Various changes are possible.

[0163] For example, as long as the position of the top end surface 14 of the semicircular tubular portion 13 inside the balloon 30 (the opening position of the sub-cavity 101L~105L for fluid supply) is closer to the top end side than the axial middle position of the expansion portion 31, it does not have to be near the top end of the cylindrical portion 311 of the expansion portion 31.

[0164] Furthermore, in the balloon electrode catheter of the present invention, the openings of the fluid supply sub-lumen and / or the fluid discharge sub-lumen may be formed on the outer peripheral surface of the outer tube so that the fluid is ejected / discharged in the radial direction of the outer tube.

[0165] Furthermore, the opening of the sub-lumen for fluid supply may be located at or near the proximal end of the expansion portion of the balloon, and the opening of the sub-lumen for fluid discharge may be located on the distal side of the axial middle position of the expansion portion.

[0166] Furthermore, the sub-cavity for fluid supply and the sub-cavity for fluid discharge may open to each other at the same axial position.

[0167] Furthermore, at least the portion of the band electrodes 51 to 54 located at the distal end side tapered portion 313 of the balloon 30 may be insulated and covered, thereby performing cauterization only with the portion of the band electrodes 51 to 54 located at the cylindrical portion 311 of the balloon 30. This can prevent restenosis of the tissue contacted by the distal end side tapered portion 313 of the balloon 30.

[0168] Here, as a solution of “insulating at least the portion of the strip electrodes 51 to 54 located in the distal tapered portion 313 of the balloon 30 ”, there can be cited a solution of insulating the entire area of ​​the distal tapered portion 313 and the distal neck portion 33 .

[0169] Description of Reference Numerals

[0170] 100: Balloon electrode catheter;

[0171] 10: External tube;

[0172] 10L: central cavity;

[0173] 101L~105L: auxiliary chamber (auxiliary chamber for fluid supply);

[0174] 107L~109L, 111L: auxiliary chamber (auxiliary chamber for fluid discharge);

[0175] 106L, 110L, 112L: secondary cavity;

[0176] 11: tubular part;

[0177] 12: top surface of the tubular portion;

[0178] 13: semicircular tubular part;

[0179] 14: apical surface of the semicircular tubular portion;

[0180] 20: Y connector;

[0181] 21: Electrical connector;

[0182] 22: Connector for fluid supply;

[0183] 23: Connector for fluid discharge;

[0184] 24: Guidewire connector;

[0185] 26: Wire protection tube;

[0186] 27: Fluid supply pipe;

[0187] 28: Fluid discharge tube;

[0188] 30: balloon;

[0189] 31: expansion part;

[0190] 311: cylindrical portion 311;

[0191] 313: top end side tapered portion 313;

[0192] 315: base end side tapered portion 315;

[0193] 33: apical lateral neck;

[0194] 35: base side neck;

[0195] 41: inner tube;

[0196] 46: apical tip;

[0197] 51-54: strip electrode (surface electrode);

[0198] 60: Metal ring;

[0199] 70: wire;

[0200] 80: temperature sensor (thermocouple);

[0201] 81: temperature measuring part of the temperature sensor;

[0202] 90: seal;

[0203] 95: Adhesive.

Claims

1. A balloon-type electrode catheter, which is used for high-frequency cauterization treatment of blood vessels or tissues around blood vessels by introduction through blood vessels, wherein the balloon-type electrode catheter is characterized by comprising: External pipe; A balloon having an expansion portion for expansion, and a base end neck portion and a top end neck portion as neck portions continuous with both ends of the expansion portion, wherein the base end neck portion is fixed to the top end portion of the outer tube; A surface electrode made of metal formed on the outer surface of the balloon at the expansion portion and the top end side neck portion; a metal ring, attached to the top side neck of the balloon and electrically connected to the top end of the surface electrode; and A guide wire, the top end of which is fixed to the metal ring, extends inside the balloon and the outer tube to the base end of the outer tube, and can be energized from the base end. The outer diameter of the metal ring is smaller than the outer diameters of the outer tube and the base end side neck portion.

2. The balloon electrode catheter according to claim 1, characterized in that: The outer tube has a central cavity and a plurality of sub-cavities arranged around the central cavity. The balloon-type electrode catheter comprises: an inner tube having a lumen, inserted through the central lumen of the outer tube and extending inside the balloon; The guide wire extends along the secondary lumen of either of the outer tubes.

3. The balloon electrode catheter according to claim 2, characterized in that: have: The top tip has a lumen communicating with the lumen of the inner tube and is fixed to the top side neck of the balloon.

4. The balloon electrode catheter according to claim 2 or 3, characterized in that: The number of the sub-lumens at the proximal end of the outer tube is greater than the number of the sub-lumens at the distal end of the outer tube.

5. The balloon-type electrode catheter according to claim 2 or 3, characterized in that: At least one of the sub-lumens of the outer tube is a fluid supply sub-lumen for supplying fluid to the interior of the balloon. At least one of the sub-lumens included in the outer tube is a fluid discharge sub-lumen for discharging the fluid supplied to the interior of the balloon from the interior of the balloon.

6. The balloon electrode catheter according to claim 5, characterized in that: The expansion portion of the balloon contains the tip portion of the outer tube fixed to the base end side neck portion of the balloon. The opening of the fluid supply sub-cavity is located on the tip side relative to the axial middle position of the expansion portion. The opening of the fluid discharge sub-cavity is located closer to the proximal end than the middle position in the axial direction of the expansion portion.

7. The balloon electrode catheter according to claim 5, characterized in that: The number of the fluid supply sub-cavities is greater than the number of the fluid discharge sub-cavities.

8. The balloon electrode catheter according to any one of claims 1 to 3, characterized in that: The surface electrodes are a plurality of strip-shaped electrodes formed to extend in the axial direction of the balloon and arranged at intervals in the circumferential direction of the balloon, and each of the top ends of the strip-shaped electrodes is electrically connected to the metal ring.

9. The balloon electrode catheter according to any one of claims 1 to 3, characterized in that: The metal ring is covered with insulation.

10. The balloon electrode catheter according to claim 9, characterized in that: The top end side neck portion is insulated and covered together with the metal ring.

11. The balloon electrode catheter according to claim 9, characterized in that: The expansion portion includes a cylindrical portion and a tapered portion connecting the cylindrical portion and the neck portion. The tapered portion on the tip end side is insulated and covered together with the metal ring.

12. The balloon electrode catheter according to any one of claims 1 to 3, characterized in that: The outer diameter of the distal end portion of the outer tube to which the proximal end side neck portion of the balloon is fixed is formed to be smaller than the outer diameter of the proximal end portion of the outer tube.

13. The balloon electrode catheter according to any one of claims 1 to 3, characterized in that: A temperature sensor is arranged on the tube wall of the balloon.

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