WO2021065872A1

WO2021065872A1 - Medical device

Info

Publication number: WO2021065872A1
Application number: PCT/JP2020/036814
Authority: WO
Inventors: 拓周; 大久保　到
Original assignee: テルモ株式会社
Priority date: 2019-09-30
Filing date: 2020-09-29
Publication date: 2021-04-08
Also published as: JP2022173169A

Abstract

Provided is a medical device which has an electrode part that closely adheres to a lesion and suppresses deformation by a valve body or an operator.　The medical device (10) comprises a long shaft part (21), and an electrode part (40) which is disposed at a distal end of the shaft part (21), is long and thin along the axis of the shaft part (21), and is radially expandable. The electrode part (40) has a first portion (41) that includes a distal end of the electrode part (40), and a second portion (42) that includes a base end of the electrode part (40), is disposed on the base end side of the first portion (41), and has an insulated surface. The first portion (41): includes a conducting part (43) having a surface conducting layer (55) that is exposed in the expanding direction of the electrode part (40); and is formed to be more flexible than the second portion (42).

Description

Medical device

The present invention relates to a medical device that is inserted into a living body and treats a living tissue by energization.

As a medical device, a device that performs treatment by an irreversible electric drilling method (IRE: Irreversible Electroporation) is known. The irreversible electrosurgical method is attracting attention because it is non-thermal and can suppress damage to surrounding blood vessels and nerves. For example, a medical device that treats a cancer that is difficult to remove by surgery by using an irreversible electric perforation method is known.

A medical device that performs an irreversible electric drilling method has a plurality of electrodes that can be expanded in the radial direction along the circumferential direction, and electricity can flow between the electrodes while the electrodes are in close contact with living tissue. Such a medical device includes, for example, those listed in Patent Document 1.

Japanese Patent No. 6013186

The medical device is inserted into the living body via a tube body inserted in the living body in advance. A valve body is provided at the entrance of the tube body inserted into the living body to prevent blood from flowing out. If the electrodes of the medical device are made flexible, the adhesion to the lesion is improved, but the electrodes are easily deformed when passing through the valve body, which may lead to poor expansion of the electrodes. Further, when the operator holds the electrode portion by hand and inserts the electrode portion, the electrode portion may be deformed.

On the other hand, if the electrodes of the medical device are hardened, the deformation when passing through the valve body is suppressed, but the adhesion at the lesion portion is lowered. In particular, when the lesion is irregular, it is difficult for the electrodes to adhere to the living tissue. The electrode of the medical device of Patent Document 1 has a small width at the tip and a base end and a large width at the middle portion, so that the rigidity of the middle portion expanding at the lesion portion is high and the adhesion at the lesion portion is low. Conceivable.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a medical device having an electrode portion that has both adhesion in a lesion portion and suppression of deformation by a valve body or an operator. To do.

The medical device according to the present invention that achieves the above object includes a long shaft portion, an electrode portion that is arranged at the tip portion of the shaft portion, is elongated along the axis of the shaft portion, and is expandable in the radial direction. The electrode portion includes a first portion including the tip end portion of the electrode portion and a proximal end portion of the electrode portion, and is arranged on the proximal end side of the first portion to insulate the surface. It has a second portion, and the first portion has a current-carrying portion including a surface conductive layer exposed in the expansion direction of the electrode portion, and is formed more flexibly than the second portion.

In the medical device configured as described above, the first portion of the electrode portion that comes into contact with the lesion portion is flexible, and the other portion is hard. Therefore, the adhesion of the electrode portion in the lesion portion and the deformation suppression by the valve body are suppressed. Can be compatible with each other. Further, by holding the second portion of the electrode portion by hand, it is possible to prevent the electrode portion from being damaged at the time of insertion.

Further, the first portion has a tip insulating portion arranged at the tip end portion of the electrode portion and the energizing portion arranged on the proximal end side of the tip insulating portion, and the energizing portion has the energizing portion. If the tip insulating portion is formed more flexibly than the second portion and the tip insulating portion is formed more flexibly than the current-carrying portion, the discontinuity of flexibility in the length direction can be relaxed.

Further, if the first portion is formed flexibly because the thickness is smaller than that of the second portion, the first portion can be easily formed flexibly by adjusting the thickness.

Further, if the first portion is formed more flexibly by having a material that is more flexible than the second portion, the first portion can be easily formed flexibly by selecting the material. ..

Further, the electrode portion is formed by laminating a plurality of layers, and the laminated state can be set if the first portion is flexibly formed by having fewer layers than the second portion. By doing so, the first portion can be easily and flexibly formed.

Further, if the first portion is flexibly formed by having a notch in the width direction at least a part in the length direction of the electrode portion, the shape, size, number, etc. of the notch may be formed. The first part can be easily and flexibly formed by the setting of.

Further, the shaft portion includes a long outer pipe and an inner pipe that is inserted into the outer pipe so as to protrude from the tip portion of the outer pipe and is slidable in the axial direction with respect to the outer pipe. However, if the tip end portion of the electrode portion is fixed to the tip end portion of the inner tube and the base end portion of the electrode portion is fixed to the tip end portion of the outer tube, it can be connected to the outer tube. By sliding the inner tube in the axial direction, the electrode portion having the flexible portion can be expanded and contracted.

Further, a balloon for expanding the electrode portion is provided at the tip end portion of the shaft portion, and the electrode portion is flexible if at least a part of the first portion is joined to the balloon. Since the first portion is joined to the balloon, the electrode portion can prevent the expansion of the balloon from being hindered.

Further, if the second portion does not come into contact with the expanded balloon, only the flexible region of the electrode portion comes into contact with the biological tissue, and the adhesion of the electrode portion can be improved.

It is a front view which shows the outline of the medical device in 1st Embodiment. It is an enlarged sectional view near the tip of a medical device. It is a top view of the electrode part. It is sectional drawing which cut | cut the electrode part in the plane parallel to the length direction. It is an enlarged cross-sectional view near the tip part of the medical device in the state where the electrode part is expanded. It is sectional drawing which cut | cut the electrode part of the 1st modification in the plane parallel to the length direction. It is sectional drawing which cut | cut the electrode part of the 2nd modification in the plane parallel to the length direction. It is sectional drawing which cut | cut the electrode part of the 3rd modification in the plane parallel to the length direction. It is sectional drawing which cut | cut the electrode part of the 4th to 6th modified examples in the plane parallel to the length direction. FIG. 5 is an enlarged cross-sectional view of the vicinity of the tip of the medical device in the second embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dimensional ratios in the drawings may be exaggerated and differ from the actual ratios for convenience of explanation. Further, in the present specification, the side of the medical device 10 to be inserted into the living body cavity is referred to as "tip" or "tip side", and the hand side to be operated is referred to as "base end" or "base end side".

The medical device 10 of the present embodiment is percutaneously inserted into a living body cavity, contacts a living body tissue at a target site, applies an electric current, and carries out an irreversible electric drilling method. The medical device 10 can also be used for high frequency ablation and electrochemotherapy.

As shown in FIG. 1, the medical device 10 has an electrode portion 40 at the tip end portion of a long tubular shaft portion 21. The shaft portion 21 has an outer pipe 30 and an inner pipe 24. The inner pipe 24 is inserted into the outer pipe 30 so as to protrude from the tip end portion of the outer pipe 30, and is slidable in the axial direction with respect to the outer pipe 30. In addition, the medical device 10 has a balloon 22. The medical device 10 has a connecting line 33 for applying a voltage to the electrode portion 40 along the length direction. The connection line 33 is connected to a power supply unit 12 provided outside the medical device 10. The power supply unit 12 can apply a voltage to the electrode unit 40. Further, the tip portion of the outer tube 30 is provided with a tip member 31 for fixing the base end portion of the electrode portion 40, and the tip portion of the inner tube 24 is provided with a tip fixing member 45 for fixing the tip portion of the electrode portion 40. Each is provided.

The balloon 22 is provided at the tip of the inner tube 24. A hub 23 is provided at the base end of the inner pipe 24.

As shown in FIG. 2, the inner pipe 24 has a double pipe structure in which the inner first pipe body 25 and the outer second pipe body 26 are arranged concentrically. A guide wire lumen 27 through which the guide wire 11 is inserted is formed inside the hollow of the first tube body 25. Further, an expansion lumen 28 for circulating the expansion fluid of the balloon 22 is formed inside the hollow of the second tube body 26 and outside the first tube body 25.

The first tubular body 25 projects further to the distal end side than the distal end of the second tubular body 26. The base end side end of the balloon 22 is fixed to the second tube body 26, and the tip end side end is fixed to the first tube body 25. As a result, the inside of the balloon 22 communicates with the expansion lumen 28. The balloon 22 can be expanded by injecting an expansion fluid into the balloon 22 via the expansion lumen 28. The expansion fluid may be a gas or a liquid, and for example, a gas such as helium gas, CO ₂ gas, O ₂ gas, or laughing gas, or a liquid such as physiological saline, a contrast medium, or a mixture thereof can be used.

The outer tube 30 and the inner tube 24 are preferably formed of a material having a certain degree of flexibility. Examples of such a material include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, and a soft polyvinyl chloride resin. Examples thereof include fluororesins such as polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane and polytetrafluoroethylene, silicone rubber and latex rubber.

The balloon 22 is formed of a thin-film balloon film, and is formed of a flexible material like the outer tube 30 and the inner tube 24. Further, the strength required to surely spread the electrode portion 40 is also required. As the material of the balloon 22, the ones mentioned above for the outer tube 30 and the inner tube 24 can be used, or other materials may be used.

Next, the electrode portion 40 will be described. The electrode portion 40 is a flexible linear member, which is elongated along the axis of the shaft portion 21 and is provided in a plurality in the circumferential direction. In FIG. 1 and the like, for simplification, only two electrode portions 40 are shown, but in reality, a large number of electrode portions 40 are provided depending on the circumferential direction. The distance between the electrode portions 40 is preferably in the range of 3 to 10 mm, but may be other than this range. Further, the electrode portions 40 may be arranged unevenly in the circumferential direction.

The tip member 31 has a plurality of fixing holes 31a in the circumferential direction in order to fix the base end portion of the electrode portion 40. The number of fixing holes 31a corresponds to the number of electrode portions 40, and the fixing holes 31a are evenly arranged in the circumferential direction of the tip member 31.

The tip fixing member 45 has a plurality of accommodating portions 45a in the circumferential direction in order to fix the tip portion of the electrode portion 40. The number of accommodating portions 45a matches the number of electrode portions 40, and the accommodating portions 45a are evenly arranged in the circumferential direction of the tip fixing member 45.

The connecting line 33 is spirally wound and embedded in the first pipe body 25 of the inner pipe 24. The connecting line 33 is pulled out from the tip of the first tubular body 25 into the tip fixing member 45, and is connected to the tip of the electrode portion 40 arranged in the accommodating portion 45a. Each electrode unit 40 is connected to the power supply unit 12 via a connection line 33. As a result, a voltage can be applied from the power supply unit 12 between the electrode units 40 adjacent to each other in the circumferential direction.

As shown in FIG. 3, the electrode portion 40 includes a first portion 41 including a tip portion of the electrode portion 40 and having an energizing portion 43, and a base end portion of the electrode portion 40, and includes a first portion 41. The second portion 42 arranged on the base end side of the above is continuous in the length direction. The surface of the second portion 42 is insulated. The first portion 41 has a conductive connecting portion 54 at the tip portion thereof, and a connecting line 33 is connected to the first portion 41. In the first portion 41, the surfaces of the conductive connecting portion 54 and the energizing portion 43 exposed in the expansion direction of the electrode portion 40 have conductivity, and the surfaces of the other portions are insulated. The first portion 41 is formed more flexibly than the second portion 42. Further, of the first portion 41, the tip insulating portion 44 on the tip side of the energizing portion 43 is formed more flexibly. Therefore, in the electrode portion 40, the energizing portion 43 is flexibly formed from the second portion 42, and the tip insulating portion 44 is flexibly formed from the energizing portion 43.

As shown in FIG. 4, the electrode portion 40 is formed by laminating a plurality of layers. In FIG. 4, the lower surface is the side in contact with the balloon 22, and the upper surface is the side in contact with the living body. The electrode portion 40 is provided with a conductive layer 50 over substantially the entire length. The conductive layer 50 is made of copper. However, the conductive layer 50 may be formed of a material having conductivity, and may be formed of a metal other than copper or the like.

A first insulating layer 51 is provided on the lower surface side of the conductive layer 50 via an adhesive layer 56. The first insulating layer 51 is made of a hard and highly insulating resin material. Examples of such a resin material include polyimide, PET, PEEK and the like.

A second insulating layer 52 is provided in the region of the second portion 42 on the upper surface side of the conductive layer 50 via the adhesive layer 56. The second insulating layer 52 is made of the same material as the first insulating layer 51. As a result, the second portion 42 is formed of three layers, the first insulating layer 51, the conductive layer 50, and the second insulating layer 52, except for the adhesive layer 56. Further, the first insulating layer 51 and the second insulating layer 52 are joined to each other by an adhesive layer 56 at the base end portion. As a result, the conductive layer 50 is not exposed on the base end surface of the electrode portion 40.

A surface conductive layer 55 is provided in the region of the current-carrying portion 43 on the upper surface side of the conductive layer 50, and is exposed in the expansion direction of the electrode portion 40. The surface conductive layer 55 is made of gold and has good conductivity and X-ray impermeableness. However, the surface conductive layer 55 may be formed of a material having conductivity and X-ray impermeableness other than gold. Since the first insulating layer 51 and the conductive layer 50 are common to the current-carrying portion 43 in the thickness direction, the flexibility of the surface conductive layer 55 determines whether or not it is more flexible than the second portion 42. Therefore, the thickness of the surface conductive layer 55 is set so that the current-carrying portion 43 is more flexible than the second portion 42.

A third insulating layer 53 and a conductive connecting portion 54 are provided in the region of the tip insulating portion 44 on the upper surface side of the conductive layer 50. The material of the third insulating layer 53 is the same as that of the first insulating layer 51 and the second insulating layer 52, and the thickness of the third insulating layer 53 is smaller than that of the second insulating layer 52. As a result, the tip insulating portion 44 is formed more flexibly than the second portion 42. Further, the thickness of the third insulating layer 53 is set so that the tip insulating portion 44 is more flexible than the energizing portion 43. The conductive connecting portion 54 is made of the same material as the surface conductive layer 55. The first insulating layer 51 and the third insulating layer 53 are joined to each other by an adhesive layer 56 at the tip portion. As a result, the conductive layer 50 is not exposed on the tip surface of the electrode portion 40.

The thickness of each layer of the electrode portion 40 can be set as follows, for example. The conductive layer 50 is 10 μm, the first insulating layer 51 is 15 μm, the second insulating layer 52 is 25 μm, the third insulating layer 53 is 10 μm, and the surface conductive layer 55 is 10 μm. However, as described above, the thickness of each layer may be set to a value other than these, provided that the energizing portion 43 is more flexible than the second portion 42 and the tip insulating portion 44 is more flexible than the energizing portion 43. Good.

By adjusting the thicknesses of the third insulating layer 53 and the surface conductive layer 55 in this way, the flexural modulus of the first portion 41 is preferably in the range of 25 to 75% of that of the second portion 42. .. However, it may be outside this range.

Further, the first insulating layer 51 and the third insulating layer 53 have a constant thickness along the length direction of the electrode portion 40 in FIG. 4, but the thickness is gradually reduced toward the tip side. Good. As a result, the tip side of the electrode portion 40 can be formed more flexibly.

As shown in FIG. 2, the electrode portion 40 has a tip insulating portion 44 bonded to the surface of the balloon 22 by adhesion. The energizing portion 43 and the second portion 42 are not joined to the balloon 22. However, the energizing portion 43 may be partially or wholly joined to the balloon 22.

When the balloon 22 expands, the electrode portion 40 expands in the radial direction as shown in FIG. Of the electrode portions 40, the tip insulating portion 44 is bonded to the balloon 22 as described above, and is supported by the balloon 22 to increase the diameter from the tip to the proximal end. Further, it is preferable that the tip insulating portion 44 is adhered so as not to have a gap between the tip insulating portion 44 and the balloon 22. This makes it possible to prevent the formation of a thrombus between the tip insulating portion 44 and the balloon 22. The energizing portion 43 is located near the central portion having the largest diameter of the balloon 22, is supported by the balloon 22, and is in close contact with the living tissue. The second portion 42 is reduced in diameter from the tip end to the base end without contacting the balloon 22.

In the electrode portion 40, the tip insulating portion 44 joined to and supported by the balloon 22 is the most flexible, the energizing portion 43 supported by the balloon 22 is the next most flexible, and the second portion 42 not in contact with the balloon 22 is the most flexible. It is formed to be hard. Therefore, when the electrode portion 40 is expanded at the lesion portion, the electrode portion 40 can be flexibly deformed according to the shape of the lesion portion, and the adhesion of the electrode portion 40 to the living tissue can be improved. it can. Further, since the first portion 41 is more flexible than the second portion 42, even if the first portion 41 is joined to the balloon 22, the expansion of the balloon can be prevented from being hindered.

On the other hand, since the second portion 42 that does not come into direct contact with the living tissue is formed to be hard, its deformation can be suppressed when the electrode portion 40 is inserted into the valve body. Further, even if the second portion 42 is held by hand and the electrode portion 40 is inserted through the valve body, since the second portion 42 has rigidity, it is possible to prevent the electrode portion 40 from being deformed or destroyed. ..

Next, a modified example of the electrode portion will be described. As shown in FIG. 6, the electrode portion 60 of the first modification has a first portion 60a on the distal end side and a second portion 60b on the proximal end side. The electrode portion 60 has a conductive layer 63 over almost the entire length, and a first insulating layer 65a is provided on the lower surface side thereof via an adhesive layer 69. Further, on the upper surface side of the conductive layer 63, a second insulating layer 65b is provided in the region of the second portion 60b via an adhesive layer 69, and a surface conductive layer 68 is provided in the energizing portion 61. .. The first insulating layer 65a and the second insulating layer 65b are joined by an adhesive layer 69 at the base end portion.

A third insulating layer 65c is formed on the upper surface side of the conductive layer 63 in the tip insulating portion 62. The tip insulating portion 62 is also formed with a conductive connecting portion 67. The third insulating layer 65c has the same thickness as the second insulating layer 65b of the second portion 60b, and is made of a material more flexible than the second insulating layer 65b. The second insulating layer 65b is made of a hard resin material such as polyimide, PET, or PEEK, like the electrode portion 40 described above, whereas the third insulating layer 65c is made of nylon, urethane, elastomer, or the like. It is made of a flexible and insulating resin material. Further, the material of the third insulating layer 65c may be a photosolder resist containing a photosensitive / thermosetting resin as a main component. The tip of the third insulating layer 65c is joined to the first insulating layer 65a via an adhesive layer 69.

Further, in this modification, it is sufficient that the third insulating layer 65c is made of a more flexible material than the second insulating layer 65b, and the third insulating layer 65c is the third insulating layer 53 in the electrode portion 40 described above. The second insulating layer 65b may be made of a similar material and the second insulating layer 65b may be made of a harder material, or the materials of both the second insulating layer 65b and the third insulating layer 65c may be changed.

In this way, by adjusting the flexibility of the third insulating layer 65c with respect to the second insulating layer 65b by selecting the material, the flexural modulus of the first portion 60a is 25 to 75% of that of the second portion 60b. It is preferably in the range. However, it may be outside this range.

Next, the electrode portion 70 of the second modification will be described. As shown in FIG. 7, the electrode portion 70 of this modified example has a first portion 70a on the distal end side and a second portion 70b on the proximal end side. The electrode portion 60 has a conductive layer 73 extending over the second portion 70b and the energizing portion 71, and on the lower surface side of the conductive layer 73, a first insulating layer 75a extends over the entire length of the electrode portion 70 via an adhesive layer 79. Is formed. On the upper surface side of the conductive layer 73, a second insulating layer 75b is formed in the region of the second portion 70b, and a surface conductive layer 78 is formed in the region of the energizing portion 71. In the tip insulating portion 72, a third insulating layer 75c is formed on the upper surface side of the first insulating layer 75a via an adhesive layer 79. That is, in this modification, the tip insulating portion 72 does not have the conductive layer 73, and the tip insulating portion 72 is thinner and more flexible than the second portion 70.

In this modification, since the tip insulating portion 72 does not have the conductive layer 73, the conductive connecting portion 77 is formed in the second portion 70. Therefore, the connection line 33 from the power supply unit 12 is connected to the base end portion of the electrode portion 70, unlike the previous examples.

By changing the layer structure of each portion constituting the electrode portion 70 in this way, the flexural modulus of the first portion 70a is preferably in the range of 25 to 75% of that of the second portion 70b. However, it may be outside this range.

Further, also in this example, the first insulating layer 75a and the third insulating layer 75c may be gradually thinned toward the tip side. As a result, the tip side of the electrode portion 70 can be formed more flexibly.

Further, two or three configurations of the tip insulating portion described above may be adopted at the same time. For example, like the electrode portion 40, the thickness of the third insulating layer 53 is smaller than that of the second insulating layer 52, and the material of the third insulating layer 65c is more flexible than that of the second insulating layer 65b like the electrode portion 60. Further, unlike the electrode portion 70, the conductive layer 73 is not provided on the tip insulating portion 72, and the third insulating layer 75c is formed on the upper surface side of the first insulating layer 75a via the adhesive layer 79. You may do so.

Next, the electrode portion 80 of the third modification will be described. As shown in FIG. 8, the electrode portion 80 of the third modification has a first portion 80a on the distal end side and a second portion 80b on the proximal end side. The configuration of the first portion 80a is the same as that of the electrode portion 40 of FIG. 4, and includes an energizing portion 81 and a tip insulating portion 82. Further, a first insulating layer 85a is provided on one side of the conductive layer 83, and a surface conductive layer 88, a third insulating layer 85c, and a conductive connecting portion 87 are provided on the other side. The second portion 80b is formed of one layer of the second insulating layer 85b. In this way, the second portion 80b may be formed by only one layer. Also in this case, the flexural modulus of the first portion 80a is preferably in the range of 25 to 75% of that of the second portion 80b. However, it may be outside this range.

Next, the

electrode portions

90, 100, 110 of the fourth to sixth modified examples will be described. In each of these, the first portion is flexibly formed by the notch in the width direction of the tip insulating portion. As shown in FIG. 9A, the electrode portion 90 of the third modification has a second portion 90b and a first portion 90a having an energizing portion 91 and a tip insulating portion 92. The tip insulating portion 92 is narrower than the second portion 90b. As a result, notches 94 in the space are formed on both sides of the tip insulating portion 92 in the width direction. Since the tip insulating portion 92 has the cutout portion 94, the first portion 90a is formed more flexibly than the second portion 90b. The width of the tip insulating portion 92 changes depending on the width of the notch portion 94, and the flexibility can be adjusted. Also in this example, the flexural modulus of the first portion 90a is preferably in the range of 25 to 75% of the second portion 90b, but may be outside this range.

As shown in FIG. 9B, the electrode portion 100 of the fourth modification has a second portion 100b and a first portion 100a having an energizing portion 101 and a tip insulating portion 102. The tip insulating portion 102 has a plurality of cutout portions 104 in which a part of both sides is notched. The notch 104 makes the first portion 100a more flexible than the second portion 100b. The flexibility of the first portion 100a can be adjusted according to the size and number of the cutout portions 104. Also in this example, the flexural modulus of the first portion 100a is preferably in the range of 25 to 75% of the second portion 100b, but may be outside this range.

As shown in FIG. 9C, the electrode portion 110 of the fifth modification has a second portion 110b and a first portion 110a having an energizing portion 111 and a tip insulating portion 112. A plurality of hole-shaped notches 114 are formed in the tip insulating portion 112. The notch 114 makes the first portion 110a more flexible than the second portion 110b. The flexibility of the first portion 110a can be adjusted by the size and number of the cutouts 114. Also in this example, the flexural modulus of the first portion 110a is preferably in the range of 25 to 75% of that of the second portion 110b, but may be outside this range.

Further, the first portion may be formed more flexibly than the second portion by combining the fourth to sixth modifications and the configurations of the electrode portions described before.

Next, the medical device 120 of the second embodiment will be described. In the first embodiment, the balloon 22 is used to expand the electrode portion 40, but in the second embodiment, the balloon is not provided. As shown in FIG. 10, the shaft portion 121 has an outer tube 122 and an inner tube 123, and the inner tube 123 inserted into the lumen of the outer tube 122 has a single lumen. A fixing member 125 is provided at the tip of the outer tube 122 to fix the base end of the electrode portion 124. A tip fixing member 126 is provided at the tip of the inner tube 123 to fix the tip of the electrode portion 124. For the electrode portion 124, either the electrode portion 40 of the first embodiment or the electrode portion of a modified example thereof can be used as it is. The electrode portion 124 can be expanded by the operator pulling the inner tube 123 in the axial direction with respect to the outer tube 122.

Next, an example of a treatment method using the medical device 10 will be described. First, an introducer (not shown) is percutaneously punctured into a blood vessel by the Seldinger method or the like. Next, after inserting the guide wire (not shown), the guiding catheter (not shown) is inserted into the introducer, the guide wire is projected toward the tip side, and then the tip of the guiding catheter is inserted into the tip of the introducer. Insert into the blood vessel through the opening. After that, the guiding catheter is gradually pushed to the target site while leading the guide wire.

Next, with the balloon 22 and the electrode portion 40 contracted, the end of the guide wire is inserted into the opening at the tip of the guide wire lumen 27 of the inner tube 24, and the guide wire is ejected from the hub 23. Next, the medical device 10 is inserted from the tip into the guiding catheter inserted into the blood vessel, and the electrode portion 40 and the shaft portion 21 are pushed along the guide wire. When inserting the electrode portion 40 into the guiding catheter, the second portion 42 of the electrode portion 40 is held by hand and inserted into the guiding catheter from the first portion 41. Since the second portion 42 is harder than the first portion 41, the electrode portion 40 can be inserted without being damaged.

After the electrode portion 40 is inserted to the target position, the expansion fluid is supplied into the balloon 22 via the expansion lumen 28 to expand the balloon 22. As a result, as shown in FIG. 5, the electrode 40 has a shape that is expanded in the radial direction by the balloon 22. In this state, a voltage is applied between the power supply unit 12 and the electrode 40.

When the voltage application is completed, the balloon 22 and the electrode portion 40 are contracted. Then, all the instruments inserted into the blood vessels are removed to complete the procedure.

As described above, the medical device 10 according to the present embodiment is an electrode arranged at a long shaft portion 21 and a tip portion of the shaft portion 21 and elongated along the axis of the shaft portion 21 and expandable in the radial direction. The electrode portion 40 includes a first portion 41 including the tip end portion of the electrode portion 40 and a proximal end portion of the electrode portion 40, and is arranged on the proximal end side of the first portion 41. The first portion 41 has a second portion 42 whose surface is insulated, and the first portion 41 has a current-carrying portion 43 including a surface conductive layer 55 exposed in the expansion direction of the electrode portion 40, and is more than a second portion 42. It is formed flexibly. As a result, the first portion 41 of the electrode portion 40 that comes into contact with the lesion portion is flexible, and the other portion is hard. Therefore, the adhesion of the electrode portion 40 in the lesion portion and the suppression of deformation by the valve body are compatible. Can be done. Further, by holding the first portion of the electrode portion 40 by hand, it is possible to prevent the electrode portion 40 from being damaged at the time of insertion.

Further, the first portion 41 has a tip insulating portion 44 on the tip side and an energizing portion 43 on the proximal end side, the energizing portion 43 is formed more flexibly than the second portion 42, and the tip insulating portion 44 is energized. If it is formed more flexibly than the portion 43, the discontinuity of flexibility in the length direction can be relaxed.

Further, if the first portion 41 is made to be flexibly formed because the thickness is smaller than that of the second portion 42, the first portion 41 can be easily formed flexibly by adjusting the thickness.

Further, if the first portion 60a is formed more flexibly by having a material more flexible than the second portion 60b, the first portion 60a can be easily formed flexibly by selecting the material. it can.

Further, the electrode portion 70 is formed by laminating a plurality of layers, and the first portion 70a can be flexibly formed by having fewer layers than the second portion 70b, so that the laminated state can be set. By doing so, the first portion 70a can be easily formed flexibly.

Further, if the first portion 80a is flexibly formed by having the notch portion 84 in the width direction at least a part in the length direction of the electrode portion 40, the shape and size of the notch portion 84 and The first portion 80a can be easily and flexibly formed by setting the number and the like.

Further, the shaft portion 21 has a long outer pipe 30 and an inner pipe 24 that is inserted into the outer pipe 30 so as to protrude from the tip portion of the outer pipe 30 and is slidable in the axial direction with respect to the outer pipe 30. , And the tip of the electrode portion 40 is fixed to the tip of the inner tube 24, and the base end of the electrode portion 40 is fixed to the tip of the outer tube 30. By sliding the outer tube 30 and the inner tube 24 in the axial direction, the electrode portion 40 having a flexible portion can be expanded and contracted.

Further, a balloon 22 for expanding the electrode portion 40 is provided at the tip portion of the shaft portion 21, and the electrode portion 40 is flexible if at least a part of the first portion 41 is joined to the balloon 22. Since the first portion 41 is joined to the balloon 22, the electrode portion 40 can prevent the expansion of the balloon 22 from being hindered.

Further, if the second portion 42 does not come into contact with the expanded balloon 22, only the flexible region of the electrode portion 40 can be brought into contact with the biological tissue, and the adhesion of the electrode portion 40 can be improved. ..

The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, the electrode portion in each example is provided with one energizing portion, but may have a plurality of energizing portions. In this case, each energizing unit can be connected in series or in parallel.

Further, the electrode portion of each example in which a plurality of layers are laminated may further have layers other than these.

This application is based on Japanese Patent Application No. 2019-179474 filed on September 30, 2019, and the disclosure contents thereof are referred to and incorporated as a whole.

10 Medical device 12 Power supply 20 Balloon catheter 21 Shaft 22 Balloon 23 Hub 24 Inner pipe 25 1st conductor 26 2nd conductor 27 Guide wire lumen 28 Expansion lumen 30 Outer pipe 31 Tip member 33 Connection line 40 Electrode Part 1 42 Second part 43 Energizing part 44 Tip insulating part 45 Tip fixing member 50 Conductive layer 51 First insulating layer 52 Second insulating layer 53 Third insulating layer 54 Conductive connection part 55 Surface conductive layer 56 Adhesive layer

Claims

With a long shaft
An electrode portion arranged at the tip portion of the shaft portion, elongated along the axis of the shaft portion, and expandable in the radial direction, is provided.
The electrode portion includes a first portion including the tip end portion of the electrode portion and a base end portion of the electrode portion, and is arranged on the base end side of the first portion and has a surface insulated second. Have a part and
The first portion is a medical device having a current-carrying portion including a surface conductive layer exposed in the expansion direction of the electrode portion, and is formed more flexibly than the second portion.
The first portion has a tip insulating portion arranged at the tip end portion of the electrode portion and the energizing portion arranged on the proximal end side of the tip insulating portion.
The medical device according to claim 1, wherein the energizing portion is formed more flexibly than the second portion, and the tip insulating portion is formed more flexibly than the energizing portion.
The medical device according to claim 1 or 2, wherein the first portion is flexibly formed because the thickness is smaller than that of the second portion.
The medical device according to claim 1 or 2, wherein the first portion is formed more flexibly by having a material that is more flexible than the second portion.
The medical device according to claim 1 or 2, wherein the electrode portion is formed by laminating a plurality of layers, and the first portion is flexibly formed by having fewer layers than the second portion.
The medical device according to claim 1 or 2, wherein the first portion is flexibly formed by having a notch in the width direction at least a part in the length direction of the electrode portion.
The shaft portion has a long outer pipe and an inner pipe that is inserted into the outer pipe so as to protrude from the tip end portion of the outer pipe and is slidable in the axial direction with respect to the outer pipe.
The tip of the electrode portion is fixed to the tip portion of the inner tube, and the base end portion of the electrode portion is fixed to the tip portion of the outer tube, any one of claims 1 to 6. The medical device described in.
Any one of claims 1 to 7, wherein a balloon for expanding the electrode portion is provided at the tip end portion of the shaft portion, and at least a part of the first portion of the electrode portion is joined to the balloon. The medical device described in the section.
The medical device according to claim 8, wherein the second part does not come into contact with the expanded balloon.