JP2015119831A - Ablation catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ablation catheter being easily operated and capable of performing a safe and appropriate ablation by accurately positioning a thermal element for performing ablation.SOLUTION: An ablation catheter 10 that is inserted into a rental artery RA for ablating the renal sympathetic nerve RN from the interior of the renal artery RA, comprises: a long tubular part 20 including a spiral groove part 82 formed at the outer surface at a distal part; a move part 43 that is spirally movable inside the groove 82 along the groove 82; and an electrode 41 that is disposed radially outward the tubular part 20 with respect to the move part 43 and comes into contact with an inner wall surface of the rental artery RA to apply a thermal influence thereto.

Description

  The present invention relates to an ablation catheter for ablating a renal sympathetic nerve from the inside of a renal artery inserted into the renal artery.

  In recent years, the effectiveness of renal sympathetic nerve ablation (renal sympathetic nerve ablation) has attracted attention as a treatment method for treatment-resistant hypertension. Increased renal sympathetic nerve activity is thought to be involved in the onset and maintenance of hypertension, and ablation of renal sympathetic nerve is expected to reduce blood pressure in patients with treatment-resistant hypertension .

  In renal sympathetic nerve ablation, first, a catheter having an ablation function is percutaneously introduced into the renal artery. Thereafter, the renal sympathetic nerve running around the renal artery is thermally damaged from within the renal artery by an electrode provided on the ablation catheter.

  For example, Patent Document 1 describes that renal sympathetic nerve ablation is performed at a plurality of locations arranged in a spiral on the inner wall surface of the renal artery. By spot-ablating at a plurality of positions where the spiral is drawn, the renal artery is prevented from being damaged all around in the same cross section in the renal artery, thereby reducing the risk of vascular stenosis.

Special table 2012-513873 gazette

  In order to perform ablation at multiple positions within the renal artery, it is necessary to operate the ablation catheter in order to move the electrode to the target position, but precise operation is required and accurate positioning is always possible. It can be difficult.

  The present invention has been made to solve the above-described problems, and is easy to operate and accurately positions a thermal element for ablation to stably perform ablation safely, promptly and appropriately. An object of the present invention is to provide an ablation catheter that enables this.

  An ablation catheter that achieves the above object is an ablation catheter that is inserted into the renal artery to ablate the renal sympathetic nerve from the inside of the renal artery, and has a length in which a spiral groove is formed on the outer surface of the distal portion. A long shaft portion, a moving portion that can move spirally in the groove portion along the groove portion, and a radially outer side of the shaft portion with respect to the moving portion, and is in contact with the inner wall surface of the renal artery. And a thermal element having a thermal effect.

  Since the ablation catheter configured as described above has a thermal element that is arranged radially outside the shaft portion with respect to the moving portion that can move spirally along the groove portion, the thermal element is spiraled along the groove portion. It is possible to perform ablation while moving in the shape. Thereby, it becomes easy to move the thermal element in a spiral shape, and an operation for ablating a portion positioned so as to draw a spiral becomes simple. Moreover, since the movement of the thermal element is defined by a preset groove, the thermal element for ablation can be accurately moved and positioned at an accurate position. And since operation becomes simple and positioning of a thermal element becomes accurate, it becomes possible to perform safer, quicker, and appropriate ablation stably.

It is a top view which shows the ablation catheter which concerns on embodiment. It is a top view which shows the distal part of the ablation catheter which concerns on embodiment. It is a longitudinal cross-sectional view which shows the distal part of the ablation catheter which concerns on embodiment. It is sectional drawing which follows the BB line of FIG. It is a schematic sectional drawing which shows the state which inserted the ablation catheter which concerns on embodiment into the renal artery. It is a schematic sectional drawing which shows the state which engaged the ablation catheter which concerns on embodiment to a renal artery. It is a schematic sectional drawing which shows the state at the time of performing ablation with the ablation catheter which concerns on embodiment. It is a schematic sectional drawing which follows the CC line of FIG. It is a schematic sectional drawing which shows the state at the time of extracting the ablation catheter which concerns on embodiment. It is a top view which shows the modification of the ablation catheter which concerns on embodiment. It is sectional drawing which follows the DD line | wire of FIG. It is a longitudinal cross-sectional view which shows the other modification of the ablation catheter which concerns on embodiment. It is a top view which shows the other modification of the ablation catheter which concerns on embodiment, (A) shows the state before expansion of an expansion body, (B) shows the state which expanded the expansion body.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the dimension ratio of drawing is exaggerated on account of description, and may differ from an actual ratio. In the specification, a side to be inserted into a blood vessel is referred to as “distal” or “distal side”, and a proximal side to be operated is referred to as “proximal” or “proximal side”.

  An ablation catheter 10 according to this embodiment shown in FIGS. 1 to 4 is a catheter for ablating (cauterizing) a renal sympathetic nerve RN (see FIG. 5) from the inside of the renal artery RA. In particular, the ablation catheter 10 according to the present embodiment is inserted from the left and right arteries (particularly the right arm artery) of the arm such as the brachial artery and radial artery to the inside of the renal artery RA via the descending aorta A. . When the ablation catheter 10 is introduced from the right arm, it reaches the descending aorta via the right subclavian artery and carotid artery. When the ablation catheter 10 is introduced from the left arm, it reaches the descending aorta via the left subclavian artery.

  The ablation catheter 10 includes a long tubular portion 20 (shaft portion) having a hollow structure, a hub 30 fixed to a proximal portion of the tubular portion 20, a heating portion 40 for heating for ablation, and the tubular portion 20. The balloon 50 provided in the distal portion of the tube portion 20 and the outer sheath 60 surrounding the outer peripheral surface of the tubular portion 20 are provided.

  The tubular portion 20 includes an inner tube 70 and an outer tube 80 that surrounds the outer peripheral surface of the inner tube 70. The inner tube 70 is a flexible tube body, a proximal portion is fixed to the hub 30, and a first lumen 71 is formed through which a fluid for expanding the balloon 50 flows. The first lumen 71 is formed from a proximal end face located in the hub 30 of the inner tube 70, and laterally (in a direction orthogonal to the axial direction) at a communication hole 72 formed in the distal portion of the inner tube 70. ).

  The outer tube 80 is a flexible tube surrounding the outer peripheral surface of the inner tube 70, the proximal portion is fixed to the hub 30, and a second lumen 81 is formed between the outer tube 80 and the inner tube 70. The second lumen 81 is formed from a proximal end face located in the hub 30 of the inner tube 70, and opens to the side by a spiral groove 82 formed in the distal portion of the outer tube 80. . The distal end of the outer tube 80 is fixed to the outer peripheral surface of the inner tube 70.

  The balloon 50 is provided on the distal side of the groove portion 82 so as to surround the outer peripheral surface of the inner tube 70 and can be expanded radially outward of the tubular portion 20. The balloon 50 communicates with the first lumen 71 through the communication hole 72, expands with the fluid supplied through the first lumen 71, and discharges the fluid through the first lumen 71. It can be reduced.

  The outer sheath 60 is disposed so as to surround the outer periphery of the tubular portion 20. The outer sheath 60 is movable in the axial direction relative to the tubular portion 20. A sheath operating portion 61 is formed at the proximal portion of the outer sheath 60 and is located on the distal side of the hub 30 and can be moved in the axial direction by manual operation.

  The hub 30 includes a hub main body 32 fixed to the proximal portion of the tubular portion 20 and an operation dial 33 provided to be rotatable with respect to the hub main body 32.

  The hub body 32 is formed with a circulation port 31 that communicates with the first lumen 71 of the tubular portion 20. The circulation port 31 is a part through which a fluid for expanding the balloon 50 is circulated. Further, the hub body 32 is formed with a connector 36 through which a lead wire 42 extending through the second lumen 81 is led out. The operation dial 33 includes a pulley 34 capable of winding an operation wire for operating the heating unit 40.

  The circulation port 31 can be connected to a tube 101 extending from the fluid supply device 100 for supplying a fluid for expanding the balloon 50. The fluid supply device 100 is, for example, a pump or a syringe.

  The heating unit 40 includes a monopolar electrode 41 (thermal element) that protrudes from the groove 82 of the outer tube 80 in the radial direction of the outer tube 80, a lead wire 42 that supplies current to the electrode 41, The movable portion 43 is movable along the spiral groove portion 82, and includes a moving portion 43 to which the electrode 41 is fixed, and an operation wire 44 for moving the moving portion 43.

  The electrode 41 can induce thermal neuromodulation in the fibers of the renal sympathetic nerve RN, causing, for example, necrosis or thermal alteration in the nerve fibers. The heating temperature of the electrode 41 is preferably 35 ° to 85 ° Celsius, and more preferably 50 ° to 80 ° Celsius, but is not limited thereto. In addition, although the heating part 40 in this embodiment is a monopolar electrode, you may comprise the ablation catheter 10 so that it may become a bipolar electrode.

  The electrode 41 is a wire whose both ends are fixed to the moving portion 43, and is curved so as to protrude from the groove portion 82 to the outside in the radial direction of the outer tube 80. The electrode 41 can be elastically deformed, and therefore the length of the outer tube 80 protruding outward in the radial direction can be freely changed. Both end portions of the electrode 41 also function as a support portion 41 </ b> A that supports a substantially central portion that protrudes and touches the living tissue so as to be movable along the radial direction of the outer tube 80 with respect to the moving portion 43. The electrode 41 may be covered with an insulating material except for the substantially central portion in contact with the living tissue.

  The lead wire 42 extends through the second lumen 81, the distal end is electrically connected to the electrode 41, and the proximal end is disposed on the connector 36 of the hub body 32.

  The moving part 43 is movable in the second lumen 81 along the spiral groove part 82, and is formed in a size that does not drop out from the groove part 82.

  The operation wire 44 has a distal end connected to the moving portion 43, extends in the second lumen 81, and a proximal end to the pulley 34 of the operation dial 33 provided in the hub 30. It is connected so that it can be wound. When the operation dial 33 is rotated, the operation wire 44 is wound up by the pulley 34 and moves in the proximal direction, and the moving portion 43 and the electrode 41 move along the spiral groove portion 82.

  The ablation catheter 10 is used in connection with an energy supply device 90. The energy supply device 90 can supply high-frequency electrical energy for ablating the living tissue to the electrode 41 via the lead wire 42 by connecting the cable 91 to the connector 36.

  The energy supply device 90 is connected to a counter electrode plate 92 that forms a counter electrode with the electrode 41 and can be collected while being attached to the body surface while dispersing current. Ablation does not necessarily have to be performed with electrical energy, for example, with microwave energy, ultrasonic energy, coherent light such as laser, incoherent light, heated fluid, cooled fluid, or the like. Also good. Ablation may be performed by cooling as well as heating.

  The length of the tubular portion 20 is preferably 1000 to 1500 mm, but is not limited to this as long as it can reach the renal artery from the introduction position into the blood vessel. The spiral pitch of the groove 82 is preferably 0.1 to 30.0 mm, but is not limited thereto. The outer diameter of the outer sheath 60 is 2.7 mm or less (preferably 2.1 mm or less so that the ablation catheter 10 can be introduced from the brachial artery or radial artery and can be inserted into the renal artery RA having an average inner diameter of about 5 to 6 mm. ) Is preferable, but not limited thereto.

  The width of the electrode 41 is preferably 0.1 to 5.0 mm, but is not limited thereto.

  Constituent materials for the inner tube 70, the outer tube 80, the outer sheath 60, and the moving portion 43 include polyamide-based resins (for example, nylon 11, nylon 12, nylon 6), polyester-based polyamide-based resins (for example, GLREL (trade name , Manufacturer DIC)), polyether-based polyamide resin (for example, Pebax (trade name, manufacturer / Atchem)), polyurethane, ABS resin, polyester elastomer resin, polyurethane elastomer resin, fluorine-based resin (PFA, PTFE, ETFE, etc.), etc. Can be used, but is not limited thereto. The insertion of the ablation catheter 10 is performed while confirming the position under fluoroscopy, so that the inner tube 70, the outer tube 80, and the outer sheath 60 are made of X-rays such as barium sulfate, bismuth oxide, and tungsten. It is preferable to provide a marker containing an impermeable material, or an X-ray impermeable material may be blended in the constituent materials of the inner tube 70, the outer tube 80, and the outer sheath 60.

  Further, the inner tube 70 and the outer tube 80 may have a multilayer structure. Further, for example, a reinforcing material obtained by braiding strands in a cylindrical shape may be embedded in the inner tube 70 and the outer tube 80. Specific examples of the reinforcing material include those constituted by thin wires such as stainless steel, tungsten, Ni-Ti, and carbon fiber. The reinforcing material may be provided only at specific portions in the axial direction of the inner tube 70 and the outer tube 80. By embedding such a reinforcing material, bending (kinking) of the ablation catheter 10 can be prevented, and torque transmission when the ablation catheter 10 is rotated can be improved.

  The constituent material of the electrode 41 is a material having conductivity, and, for example, stainless steel, Ni—Ti alloy, platinum iridium, and the like can be preferably used, but are not limited thereto.

  The moving unit 43 and the operation wire 44 may be configured integrally with the electrode 41. Further, the operation wire 44 may serve as a lead wire for supplying a current to the electrode 41.

  Examples of the constituent material of the balloon 50 include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, and soft polyvinyl chloride resin. Polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, thermoplastic resin such as fluororesin, silicone rubber, latex rubber and the like can be used, but are not limited thereto.

  Next, an example of how to use the ablation catheter 10 according to the present embodiment will be described.

  First, a catheter introducer (not shown) is punctured into the brachial artery or radial artery by a known technique such as the Seldinger method, and the guiding catheter 110 with the guide wire inserted is inserted into the catheter introducer.

  Next, the guiding catheter 110 and the guide wire are gradually fed with the guide wire preceding the guiding catheter 110, and the distal portion of the guiding catheter 110 is near the entrance of the renal artery RA of the descending aorta A. To reach. At this time, an operation in which the guide wire is taken in and out and the guiding catheter 110 is advanced and retracted and rotated appropriately is performed so that the distal end of the guiding catheter 110 can pass through the bent portion of the blood vessel.

  After the distal portion of the guiding catheter 110 reaches the vicinity of the entrance of the renal artery RA in the descending aorta A, the guide wire is withdrawn from the guiding catheter 110 and the ablation catheter 10 is inserted into the guiding catheter 110. At this time, the distal portion of the tubular portion 20 is covered with the outer sheath 60, and the electrode 41 is elastically deformed and accommodated in the outer sheath 60. The electrode 41 is located at the most distal portion of the groove 82 extending in a spiral shape.

  Next, the ablation catheter 10 is protruded from the distal opening of the guiding catheter 110, and the ablation catheter 10 is inserted from the descending aorta A into the renal artery RA as shown in FIG.

  Next, the sheath operating portion 61 of the outer sheath 60 is moved in the proximal direction, and the distal portion of the tubular portion 20 is released from the inside of the outer sheath 60 as shown in FIG. Thereby, the groove part 82 of the outer tube | pipe 80 is exposed, and the electrode 41 protrudes with an own restoring force.

  Next, the ablation catheter 10 is positioned at a target position in the renal artery RA, and the tube 101 extending from the fluid supply device 100 is connected to the flow port 31 of the ablation catheter 10. Then, when the fluid is supplied from the fluid supply device 100, the fluid flows into the balloon 50 through the first lumen 71, the balloon 50 expands and contacts the inner wall surface of the renal artery RA, and the electrode 41 It contacts the inner wall surface of the renal artery RA. Thereby, the ablation catheter 10 is firmly engaged with the renal artery RA. Therefore, by introducing from the arteries of the arm, the balloon 50 is stronger than the case of introducing from the arteries of the foot, even though the ablation catheter 10 is easily swayed by the influence of the pulsation of the heart and the expansion and contraction of the aorta. By being engaged, the contact position of the electrode 41 with respect to the renal artery RA becomes difficult to shift.

  Next, a cable 91 extending from the energy supply device 90 is connected to the connector 36 of the ablation catheter 10, and a counter electrode plate 92 is attached to the patient's body surface.

  Next, when high-frequency electrical energy is supplied from the energy supply device 90 to the heating unit 40, the living tissue in the vicinity of the electrode 41 is heated because the counter electrode plate 92 is provided on the body surface. Thereby, for example, necrosis or thermal alteration occurs in the fibers of the renal sympathetic nerve RN located in the vicinity of the electrode 41. At this time, since the ablation catheter 10 is firmly engaged with the renal artery RA by the balloon 50, the electrode 41 can be easily placed at a target position for a predetermined time (for example, 10 to 120 seconds) for supplying electric energy. Can be maintained and safe and appropriate ablation can be performed. Thereafter, when the operation dial 33 is rotated, the operation wire 44 is wound around the pulley 34 and the moving portion 43 moves in the proximal direction, and is connected to the moving portion 43 as shown in FIGS. The electrode 41 moves along the spiral groove 82. As a result, the electrode 41 is ablated at each position while being sequentially moved to different positions P1, P2, P3, P4... Along the longitudinal axis of the renal artery RA and also in the circumferential direction. It can be performed. In this embodiment, the electrode 41 is moved about every 5 to 10 mm along the longitudinal axis of the renal artery RA, and about 4 to 6 spots are damaged in spots every 90 to 270 degrees in the circumferential direction. Form a site. In addition, the position and number to heat may not be in said range. In this way, by moving the electrode 41 spirally along the groove 82, the renal sympathetic nerve RN localized outside the renal artery outer membrane and the outer membrane is necrotized spatially all around in the renal artery RA. Or can cause thermal alteration. At this time, since ablation is performed in a spot-like manner so as to draw a spiral, the renal artery RA is not damaged all around the cross section in the renal artery RA, and the risk of vascular stenosis can be reduced.

  In the above example, the electrode 41 is moved, and spot ablation is performed at each position P1, P2, P3, P4..., But the electrode 41 is moved to the groove 82 while heating by the electrode 41. It is also possible to perform ablation continuously by moving along. When performing ablation continuously, the moving speed of the electrode 41 is preferably 0.01 to 0.03 mm / sec. However, it is possible to cause necrosis and thermal alteration in the fibers of the renal sympathetic nerve RN. If it is, it will not be limited to this.

  Thereafter, when the fluid is discharged from the balloon 50 through the first lumen 71 and the balloon 50 is deflated, the balloon 50 is separated from the inner wall surface of the renal artery RA, and the engagement of the ablation catheter 10 with the renal artery RA is released. Is done. Next, the outer sheath 60 is moved in the distal direction with respect to the tubular portion 20, and the entire distal portion of the tubular portion 20 is accommodated in the outer sheath 60. Thereby, the electrode 41 is elastically deformed and accommodated in the outer sheath 60. Thereafter, the ablation catheter 10 is accommodated in the guiding catheter 110, and the ablation catheter 10, the guiding catheter 110, and the catheter introducer are removed as shown in FIG. 9 to complete the procedure. After ablation in one of the left and right renal arteries RA, the ablation catheter 10 may be moved to the other renal artery RA and ablation may be performed as described above.

  As described above, the ablation catheter 10 according to the present embodiment is an ablation catheter 10 that is inserted into the renal artery RA to ablate the renal sympathetic nerve RN from the inside of the renal artery RA. A long tubular portion 20 (shaft portion) in which a spiral groove portion 82 is formed, a moving portion 43 that can move spirally along the groove portion 82 in the groove portion 82, and a tubular shape with respect to the moving portion 43. And an electrode 41 (thermal element) that is disposed on the radially outer side of the portion 20 and that contacts the inner wall surface of the renal artery RA to exert a thermal effect. For this reason, it becomes possible to perform ablation while moving the electrode 41 along the groove 82 in a spiral shape. Thereby, it becomes easy to move the electrode 41 in a spiral shape, and an operation for ablating a portion positioned so as to draw a spiral becomes simple. Further, since the movement of the electrode 41 is defined by the preset groove portion 82, the electrode 41 for ablation can be accurately moved and positioned at an accurate position. And since operation becomes simple and positioning of the electrode 41 becomes accurate, it becomes possible to perform safer, quicker, and appropriate ablation stably.

  Further, since the ablation catheter 10 has a support portion 41A that supports the electrode 41 (thermal element) so as to be movable along the radial direction of the tubular portion 20 (shaft portion) with respect to the moving portion 43, the outer periphery of the tubular portion 20 The electrode 41 can be reliably brought into contact with the inner wall surface of the renal artery RA without being affected by the distance from the surface to the inner wall surface of the renal artery RA, and appropriate ablation can be performed.

  In addition, since the ablation catheter 10 includes a balloon 50 (expanded body) that is disposed at a distal portion of the tubular portion 20 (shaft portion) and can be expanded and contracted radially outward of the tubular portion 20, the balloon 50 , The tubular portion 20 can be firmly engaged with the renal artery RA, the contact position of the electrode 41 with the renal artery RA is difficult to shift, and safer and more appropriate ablation can be performed. .

  Note that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, a temperature sensor that measures temperature in order to monitor and control heating by the electrode 41 may be provided in the vicinity of the electrode 41 that performs heating. The temperature sensor is, for example, a thermocouple or a thermistor.

  Moreover, in this embodiment, in order to form the groove part 82, the tubular outer tube | pipe 80 is provided in the outer peripheral surface of the inner tube | pipe 70. However, like the ablation catheter as a modification shown in FIGS. A spiral member 120 that includes the spiral groove 121 and is movable by the moving unit 43 may be fixed to the outer peripheral surface of the inner tube 70. Further, the electrode 130 may be supported by a support portion 131 that includes an elastic member such as a coil spring and can be expanded and contracted.

  In addition, as shown in FIG. 12, the tubular portion 140 (shaft portion) penetrates from the proximal side to the distal side of the electrode 41 (thermal element), and allows the external fluid to be taken in and circulated. 141 may be included. In this way, even if the balloon 50 is expanded, blood flow can be secured through the flow path, and the load on the living body can be reduced.

  In this embodiment, the balloon 50 is provided to firmly engage the tubular portion 20 with the renal artery RA. However, if the balloon 50 can be expanded and contracted and can be engaged with the renal artery RA, May be provided with different types of extensions. As the expansion body, for example, as shown in FIG. 13A, a movable inner tube 160 that is movable relative to the tubular portion 150 is provided inside the tubular portion 150 in which the groove portion 82 is provided. Further, the expansion body 170 connected to the moving inner tube 160 may be applied. The expansion body 170 has a proximal end 172 connected to the distal portion of the tubular portion 150 and a distal end 173 connected to the outer peripheral surface of the moving inner tube 160. The expansion body 170 is formed with a plurality of slits 171 extending in the axial direction. By moving the moving inner tube 160 in the proximal direction with respect to the tubular portion 150, as shown in FIG. It can be deformed so as to protrude outward in the direction.

  Moreover, as an expansion body, the shaft part itself in which the groove part is formed may be deformable so as to expand radially outward.

  Further, the outer sheath 60 is not necessarily provided. For example, the guiding catheter 120 can also serve as the outer sheath 60 that houses the electrode 41.

  Further, the balloon (expansion body) is not necessarily provided. The balloon may be provided on the proximal side rather than on the distal side of the groove 82, or may be provided on both sides.

  Further, the blood vessel into which the ablation catheter is inserted is not limited, and the present invention can also be applied to an ablation catheter that is inserted not from an arm artery, but from a leg artery such as a femoral artery.

  The present invention also provides an ablation method for ablating the renal sympathetic nerve from the inside of the renal artery. The ablation method is an ablation method in which the renal sympathetic nerve is ablated from the inside of the renal artery, and (i) a long shaft portion in which a spiral groove portion is formed on the outer surface of the distal portion, and the inside of the groove portion. Providing an ablation catheter comprising a moving part that can move spirally along the groove part, and a thermal element that protrudes radially outward of the shaft part from the moving part; and (ii) the thermal element Ablating by contacting the inner wall of the renal artery and (iii) moving the thermal element spirally along the groove. With such an ablation method, it is easy to move the thermal element in a spiral shape along the groove portion, and the operation of ablating a portion located so as to draw a spiral becomes simple. Moreover, since the movement of the thermal element is defined by a preset groove, the thermal element for ablation can be accurately moved and positioned at an accurate position. And since operation becomes simple and positioning of a thermal element becomes accurate, it becomes possible to perform safer, quicker, and appropriate ablation stably. Then, by performing appropriate ablation on the renal sympathetic nerve, a blood pressure lowering effect can be obtained satisfactorily.

  The ablation method may support the thermal element so as to be movable in the radial direction of the shaft portion with respect to the moving portion in the step of performing the ablation and the step of moving the thermal element in a spiral shape. In this way, the thermal element can be reliably brought into contact with the inner wall surface of the renal artery without being affected by the distance from the outer peripheral surface of the shaft portion to the inner wall surface of the renal artery, and appropriate ablation is performed. It becomes possible.

  Further, in the ablation method, before the ablation step, an expansion body that is disposed at a distal portion of the shaft portion and can be expanded and contracted radially outward of the shaft portion is formed in the renal artery. There may be a step of expanding and bringing the expanded body into contact with the inner wall surface of the renal artery. In this way, by expanding the expansion body, the shaft portion can be firmly engaged with the renal artery, the contact position of the thermal element with the renal artery is difficult to shift, and safer and appropriate ablation is performed. It becomes possible.

10 Ablation catheter,
20, 140, 150 Tubular part (shaft part),
41,130 electrodes (thermal elements),
41A, 131 support part,
43 Moving part,
50 Balloon (expanded body),
60 outer sheath,
70 inner pipe,
71 The first lumen,
80 outer tube,
81 Second lumen,
82, 121 grooves,
170 extension,
A descending aorta,
R kidney,
RA renal artery,
RN Renal sympathetic nerve.

Claims (4)

An ablation catheter for ablating the renal sympathetic nerve from the inside of the renal artery inserted into the renal artery,
A long shaft part in which a spiral groove is formed on the outer surface of the distal part;
A moving part capable of moving spirally along the groove part in the groove part;
An ablation catheter having a thermal element that is disposed on a radially outer side of the shaft portion with respect to the moving portion and that has a thermal effect by contacting an inner wall surface of a renal artery.   The ablation catheter according to claim 1, further comprising a support portion that supports the thermal element so as to be movable in a radial direction of the shaft portion with respect to the moving portion.   The ablation catheter according to claim 1, further comprising an expansion body that is disposed at a distal portion of the shaft portion and can be expanded and contracted radially outward of the shaft portion.   The ablation according to any one of claims 1 to 3, wherein the shaft portion has a flow path that penetrates from the proximal side to the distal side of the thermal element and can take in and circulate an external fluid. catheter.

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