JP6383250B2 - Ablation catheter - Google Patents

Description

  The present invention relates to an ablation catheter for performing ablation treatment in a living body lumen.

  The ablation catheter is disposed on the outer periphery of the shaft part inserted into the lumen in the living body and the shaft part, and applies energy to the treatment target site (the wall tissue of the lumen) related to the diseased part in the living body. And is used to recover symptoms such as dysfunction caused by a disease (see, for example, Patent Document 1).

Special table 2012-513873 gazette

  However, a catheter like patent document 1 is comprised so that a front-end | tip part can be deform | transformed flexibly so that a thermal element may contact a treatment object site | part. Therefore, when the thermal element disposed at the distal end portion of the catheter is disposed at the treatment target site, the force for holding the thermal element at the treatment target site is not sufficient. For this reason, there is a possibility that the thermal element is displaced during the treatment due to an unexpected impact on the catheter, and a good treatment effect cannot be obtained. In such a case, it is necessary to rearrange the thermal element, which has a problem that the treatment time becomes long. In addition, it is difficult to adjust the position of the thermal element of the catheter as in Patent Document 1 when it is not desired to arrange the thermal element on the distal side of the treatment target site in the living body.

  The present invention has been made in order to solve the problems associated with the above-described prior art, and an object thereof is to provide an ablation catheter capable of suppressing the displacement of a thermal element.

In order to achieve the above object, the present invention is an ablation catheter having a shaft portion inserted into a lumen in a living body. The shaft portion includes an expansion body that can be expanded and contracted, at least one thermal element that thermally affects a living tissue, and a deformation portion that is located on the proximal side of the expansion body. The deformable portion has a curved region that is curved and contacts the wall tissue of the lumen in a state where the expansion body is expanded and anchored to the wall tissue of the lumen. The thermal element is disposed in the curved region. The deformable portion has a curved support region extending from both ends of the curved region, and the curved region is more flexible or stretchable than the curved support region. The thermal element is annular and is arranged so as to cover the outer periphery of the curved region.

According to the present invention, when the expansion body expands, the distal end side of the ablation catheter is fixed to the wall tissue of the living body lumen with respect to the thermal element disposed on the shaft portion. Therefore, in the ablation catheter, when the shaft portion is pushed toward the distal end side in a state where the expansion body is expanded, the bending region of the deforming portion is bent and comes into contact with the wall tissue in the living body lumen. For this reason, since the thermal element arrange | positioned in a curvature area | region contacts the wall tissue in a biological lumen, ablation treatment can be performed easily. In addition, since the distal end side of the shaft portion is fixed by the expansion of the expansion body, the ablation catheter of the present invention can suppress the displacement of the thermal element disposed on the shaft portion toward the distal end side, so that The thermal element can be stably fixed. Specifically, when the thermal effect is applied to the wall tissue of the lumen that is the treatment target site related to the diseased part by applying heat to the wall tissue of the lumen, the expansion body that is anchored to the wall tissue of the lumen, The positional deviation of the curved region of the deforming portion can be suppressed. For this reason, the thermal element arranged in the curved region comes into contact with the wall tissue of the lumen, which is the treatment target site, in a state where the occurrence of positional deviation is suppressed. Therefore, this invention can provide the ablation catheter which can suppress the position shift of a thermal element.
Moreover, the said deformation | transformation part has a curved support area | region extended from the both ends of the said curved area, and the said curved area has a softness | flexibility or a stretching property rather than the said curved support area. Thereby, a deformation | transformation part curves by pushing a shaft part to the front end side, and contacts the wall tissue of a lumen. Specifically, when the shaft portion is pushed to the distal end side, the deformed portion is bent so that the curved region having flexibility or stretchability is more apex than the curved support region, and contacts the wall tissue of the lumen. To do. For this reason, the catheter having the deformed portion of the present invention is bent by simply being pushed in, and the bent region having the thermal element can be brought into contact with the wall tissue of the lumen.
Furthermore, the said thermal element is cyclic | annular and is arrange | positioned so that the outer periphery of a curved area | region may be covered. Thereby, since a thermal element exists in the whole outer periphery of the circumferential direction of the predetermined area of a curved area | region, it is possible to make it contact with the wall structure | tissue of a lumen reliably.

  It is preferable that the deforming portion has at least three or more curved support regions, and the curved regions and the curved support regions are alternately arranged. Accordingly, the bending support regions at both ends of the bending region support the bending region so as to contact the wall tissue of the lumen when the deforming portion is bent. Therefore, when the deformed portion is bent, the catheter of the present invention can more reliably bring the curved region of the deformed portion into contact with the wall tissue of the lumen.

  The deforming portion has at least two or more curved regions in which the thermal elements are arranged, and the length of the curved region in the axial direction is shorter than the length of the curved support region in the axial direction. It is preferable. Thereby, since the catheter of this invention has two or more thermal elements, it can ablate to two or more living tissues simultaneously. Therefore, the treatment time can be shortened. In addition, since the length of the curved support region in the axial direction is longer than the length of the curved region in the axial direction, the curved region is more reliably brought into contact with the wall tissue of the lumen when the deformed portion is curved. Can do.

It is preferable that the deforming portion bends when the shaft portion is pushed to the distal end side in a state where the expansion body is expanded and anchored to the wall tissue of the lumen. In this case, since the deformable portion having the thermal element can be reliably brought into contact with different positions in the axial direction or the circumferential direction of the wall tissue of the lumen, the treatment time can be shortened. Further, since the deformed portion is curved, it is possible to reliably contact the wall tissue of the lumen.

  The thermal element is preferably composed of a monopolar electrode. In this case, it is possible to simplify the configuration of the thermal element.

  It is preferable that the expansion body is three-dimensionally formed of a wire material having self-expandability and elasticity. In this case, since the expansion body is composed of a wire, body fluid such as blood can pass through even in an expanded state. Therefore, the wall tissue of the lumen that has been heat-denatured after the treatment can be cooled by body fluid. Moreover, since the expansion body is comprised with the wire, even if it is the expanded state, a bodily fluid is not completely stopped.

  When the expansion body is composed of an expandable and contractible balloon arranged so as to cover the outer periphery of the shaft portion, the balloon is anchored in contact with the entire inner wall of the lumen by expanding, so that the deformable portion Is fixed with respect to the axial, circumferential and radial directions of the lumen and is positioned in the center of the lumen. Therefore, it is possible to satisfactorily suppress the displacement of the thermal element.

It is the schematic for demonstrating the ablation system which has an ablation catheter concerning Embodiment 1. FIG. It is a side view for demonstrating the ablation catheter shown by FIG. It is sectional drawing regarding line III-III of FIG. It is sectional drawing for demonstrating the use of an ablation catheter. It is sectional drawing for demonstrating the shaft part and sheath of an ablation catheter. It is sectional drawing for demonstrating the hand operation part of an ablation catheter. It is sectional drawing for demonstrating an example of the usage method of an ablation system. It is the schematic for demonstrating the modifications 1-3 which concern on Embodiment 1. FIG. FIG. 10 is a cross-sectional view for explaining a hand operating part and a sheath of Modification 4 according to Embodiment 1. It is a figure for demonstrating the ablation catheter which concerns on Embodiment 2. FIG. It is sectional drawing for demonstrating the shaft front-end | tip part shown by FIG. It is sectional drawing for demonstrating operation | movement of the balloon shown by FIG. FIG. 10 is a diagram for explaining a first modification according to the second embodiment. It is sectional drawing for demonstrating the shaft front-end | tip part shown by FIG.

  Hereinafter, embodiments of the present invention will be described 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.

  1 is a schematic view for explaining an ablation system having an ablation catheter according to Embodiment 1, FIG. 2 is a side view for explaining the ablation catheter shown in FIG. 1, and FIG. Sectional drawing regarding line III-III, FIG. 4 is sectional drawing for demonstrating the use of an ablation catheter.

  The ablation system 100 according to the first embodiment is applied, for example, for treatment aimed at lowering blood pressure in a treatment resistant hypertensive patient. As shown in FIG. 1, the ablation catheter 110, the energy supply device 180, and the counter electrode plate are used. 188.

  As shown in FIG. 2, the ablation catheter 110 is a rapid exchange (RX) type, and includes a shaft portion 120 and a sheath 150 that are inserted into a lumen in a living body, and a hand operation portion 160 that is operated by a surgeon at hand. And having. The lumen in the living body is an aorta 300 and a renal artery 310 as shown in FIG. Hereinafter, the side to be inserted into the lumen is referred to as “tip” or “tip side”, and the proximal side for operation is referred to as “base end” or “base end side”.

  The shaft portion 120 includes a shaft main body 122, a basket 124 that is an expansion body, a first electrode tip 126, a second electrode tip 128, temperature measuring portions 130 and 132, and a deformation portion 134.

  The shaft body 122 is a solid tubular member, extends from the proximal end of the basket 124, and is connected to the connector 166.

  The basket 124 is a self-expanding expansion body disposed at the tip of the shaft main body 122, and is formed of a plurality of elastic wires. The basket 124 is configured to expand when exposed from the sheath 150 and to contact the wall tissue of the renal artery 310. The shaft body 122 and the basket 124 may be integrally formed. In this case, the basket 124 can be configured by cutting a tubular member constituting the shaft portion 120 by laser cutting or the like.

  Further, since the basket 124 is anchored to the wall tissue of the renal artery 310 by being expanded, the movement of the shaft portion 120 in the distal direction is inhibited. Therefore, when the deforming portion 134 of the shaft main body 122 is curved and contacts the wall tissue of the renal artery 310, the displacement of the deforming portion 134 that contacts the wall tissue can be suppressed. Since the basket 124 allows blood circulation, the wall tissue of the renal artery 310 that has been heat denatured after the treatment can be cooled by the blood.

  In addition, although the tip protrusion 125 is attached to the tip side of the basket 124 in the ablation catheter of FIG. 1, the tip protrusion 125 may not be attached to the ablation catheter.

  The shaft body 122 and the basket 124 may have an insulating coating layer in order to prevent energy transmission from the lead wire.

The deforming portion 134 is a part of the shaft portion 120 and is located on the proximal end side with respect to the basket 124 that is an expansion body. The deforming portion 134 is configured to bend and contact the renal artery 310 when the shaft portion 120 is pushed to the distal end side in a state where the basket 124 is expanded and anchored to the wall tissue of the renal artery 310. (See FIG. 4). Specifically, the deforming portion 134 is curved region 135A that curves and contacts the wall tissue weaves T ₁ and T ₂ of the renal artery 310 in a state where the basket 124 is expanded and anchored to the wall tissue of the renal artery 310. And a curved support region 135B extending from both ends of the curved region 135A (see FIG. 2). Since the curved region 135A is more flexible or stretchable than the curved support region 135B, when the basket portion 124 is expanded and anchored to the wall tissue of the renal artery 310, the curved portion 135A is curved when pushed into the distal end side. The region 135A is curved starting from the region 135A and comes into contact with the wall tissue T ₁ and T ₂ of the renal artery 310. At this time, when the deformable portion 134 has two or more curved regions 135A, the axial length and the circumference of the renal artery 310 are reduced by making the axial length of the curved region 135A shorter than the axial length of the curved support region 135B. The curved region 135A can be brought into contact with wall tissues having different directions. Note that the curved region and the curved support region of the deformable portion can be formed, for example, by changing the physical properties of the shaft body and the tube.

Moreover, it is preferable that the deformation | transformation part 134 has at least 3 or more curved support area | regions 135B, and the curved area | region 135A and the curved support area | region 135B are arrange | positioned alternately. With such a configuration, the deformable portion 134 can have two or more curved regions 135 </ b> A that contact the wall tissue of the renal artery 310. Further, the curved support regions 135B at both ends of the curved region can support the curved region 135A so as to contact the wall tissue T ₁ and T ₂ of the renal artery 310.

  The first electrode chip 126 and the second electrode chip 128 are thermal elements that apply heat to the wall tissue of the renal artery 310 that is a treatment target site in the diseased part to thermally denature, and are configured by monopolar electrodes. . Thus, the first electrode tip 126 and the second electrode tip 128 come into contact with the wall tissue of the renal artery 310 when the curved region of the deformable portion 134 comes into contact with the wall tissue of the renal artery 310. Further, the first electrode tip 126 and the second electrode tip 128 are sequentially arranged apart from the outer periphery of the shaft portion 120 toward the proximal end side. The tissue thermal degeneration is, for example, cauterization or necrosis of the fibers of the renal sympathetic nerve 320 (see FIG. 4) that runs around the renal artery 310.

  Note that the first electrode chip 126 and the second electrode chip 128 may be provided with a measurement unit in order to measure the ablation heating temperature. For example, as shown in FIG. 3, in order to measure the ablation heating temperature, temperature measuring units 130 and 132 made of thermocouples extending inside the shaft portion 120 may be provided. The tip of the temperature measuring unit 130 is fixed to the first electrode chip 126 and is configured to measure the temperature of the first electrode chip 126. The tip of the temperature measuring unit 132 is fixed to the second electrode chip 128 and is configured to measure the temperature of the second electrode chip 128.

  The sheath 150 is a hollow tubular member, and the shaft portion 120 is inserted therein.

  The hand operation unit 160 has a drive mechanism 170 that advances the sheath 150 forward and retracts the proximal end. The drive mechanism 170 is used to expose the basket 124 and the deformed portion 134 of the shaft portion 120 from the distal end of the sheath 150 and allow the basket 124 to expand and bend the deformed portion 134.

  The energy supply device 180 is a high-frequency generator that is connected or built in a computing means such as a computer, and includes a first cable 184 and a second cable 186.

  The first cable 184 is connected to the ablation catheter 110 via the connector 182. The connector 182 is connected to the first electrode chip 126, the second electrode chip 128, and the temperature measuring units 130 and 132.

  Therefore, the energy supply device 180 supplies a high-frequency current to the first electrode chip 126 and the second electrode chip 128 via the first cable 184 and the connector 182 and detects a voltage generated in the temperature measuring units 130 and 132. By measuring, the temperature of the first electrode chip 126 and the second electrode chip 128 can be measured. That is, the energy supply device 180 can control the heating temperature, the heating time, and the like while monitoring the heating temperature of the ablation.

  The second cable 186 is connected to the counter electrode plate 188. The counter electrode plate 188 forms a counter electrode with the first electrode chip 126 and the second electrode chip 128 and is attached to the body surface of the living body. Thereby, a circuit is formed among the energy supply device 180, the first electrode chip 126 and the second electrode chip 128, the living body, and the counter electrode plate 188.

  Therefore, the high-frequency current supplied from the energy supply device 180 flows into the living tissue via the first electrode chip 126 and the second electrode chip 128 and returns to the counter electrode plate 188. At this time, Joule heat is generated by resistance heating. Will occur. Because the current concentrates on the wall tissue of the lumen that is a contact surface between the first electrode chip 126 and the second electrode chip 128 and the living tissue (the treatment target site including the renal sympathetic nerve 320 that runs around the renal artery 310). Local temperature rise is caused by Joule heat. This promotes thermal degeneration of the tissue, for example, cauterization and necrosis of the fibers of the renal sympathetic nerve 320.

  When the ablation catheter 110 is thermally denatured by applying energy with the first electrode tip 126 and the second electrode tip 128 to the wall tissue of the renal artery 310 that is the treatment target site related to the diseased part, as described above, The curved region of the deformable portion 134 can be fixed to the wall tissue of the renal artery 310 by pushing the shaft portion 120 toward the distal end side while the basket 124 is anchored to the wall tissue of the renal artery 310.

  In this case, since the first electrode chip 126 and the second electrode chip 128 are disposed in the curved region of the deformable portion 134, the occurrence of displacement is suppressed (see FIG. 4). Thereby, a favorable treatment effect is obtained, and since the rearrangement of the first electrode tip 126 and the second electrode tip 128 is not required, it is possible to suppress an increase in treatment time. A good surgical effect is, for example, an increase in the ablation success probability and an improvement in the safety of the ablation procedure (other than the target site is not ablated).

  The first electrode chip 126 and the second electrode chip 128 are composed of monopolar electrodes, and the configuration can be simplified.

  Since it has two electrode tips (the first electrode tip 126 and the second electrode tip 128) as a thermal element that imparts energy to the wall tissue of the lumen and thermally denatures it, the operation time can be shortened. Is possible.

  The ablation catheter 110 can also have an impedance sensor for examining the contact state between the electrode tip and the living tissue. If necessary, a direct current can be applied as ablation energy instead of the high-frequency current.

  The temperature measuring units 130 and 132 are not limited to a form constituted by thermocouples made of two different types of metal wires, and for example, a thermistor can be applied. In addition, one or both of the temperature measuring units 130 and 132 can be omitted as necessary.

  Next, a sheath, a shaft part, and a hand operation part are explained in full detail one by one.

  FIG. 5 is a cross-sectional view for explaining a shaft portion and a sheath of the ablation catheter.

  As shown in FIG. 5, the sheath 150 is a long hollow body, and has a through hole 154 and a lumen 158. The through-hole 154 is disposed in the raised portion 153 of the distal end portion 151, and is configured so that the guide wire 190 can be inserted. The lumen 158 extends from the distal end portion 151 toward the proximal end portion 156, and is configured so that the shaft portion 120 can be inserted.

  The shaft portion 120 is a long tubular body, and includes a shaft main body 122, a basket 124, a first electrode tip 126, a second electrode tip 128, temperature measuring portions 130 and 132, a deformation portion 134, a tube 136 and a lumen 138. . In addition, lead wires 127 and 129 and measuring units 130 and 132 are arranged on the outer peripheral surface of the shaft main body 122 along the axial direction. And the tube 136 is arrange | positioned so that the whole shaft main body 122, the lead wires 127 and 129, and the measurement parts 130 and 132 may be coat | covered (refer FIG. 3). The tube 136 is formed of an insulating material so that energy or the like does not leak from the lead wires 127 and 129. Therefore, the tube only needs to cover the shaft main body 122 up to the vicinity of the first electrode tip 126 having the lead wire 127. The shaft portion 120 is disposed on the lumen 158 of the sheath 150 so as to protrude from the distal end portion 151 of the sheath 150. In the state where the shaft portion 120 is inserted into the sheath 150, the basket 124 is contracted, and the deformable portion 134 is substantially linear.

  The first electrode tip 126 and the second electrode tip 128 are annular and are arranged so as to cover the outer periphery of the curved region of the deformable portion 134. Therefore, the first electrode tip 126 and the second electrode tip 128 can be reliably brought into contact with the wall tissue of the renal artery 310. The 1st electrode tip 126 and the 2nd electrode tip 128 are not limited to the form which is annular, for example, can also have circular arc shape and a rectangular section.

  The deformed portion 134 is bent by being pushed toward the distal end side in a state where the basket 124 is expanded and anchored to the wall tissue of the renal artery 310, and the curved support regions at both ends of the curved region serve as struts. It is preferable to have flexibility or stretchability that allows the curved region to contact the wall tissue of the renal artery 310 (FIG. 4). In this case, the deformable portion 134 is curved by simply being pushed in, and hence the operability is good.

  The tube 136 extends from the first electrode tip 126 to the distal end side, and thereafter, the shaft body 122 is configured to be exposed.

  The lumen 138 is formed by a space between the inner peripheral surface of the tube 136 and the outer peripheral surface of the shaft main body 122, and lead wires 127 and 129 and temperature measuring units 130 and 132 are arranged (see FIG. 3). The lumen 138 is closed at the tip of the tube 136.

  The lead wire 127 has a tip fixed to the first electrode chip 126 and is used to supply a high-frequency current from the energy supply device 180 to the first electrode chip 126. The lead wire 129 has a tip fixed to the second electrode chip 128 and is used to supply a high-frequency current from the energy supply device 180 to the second electrode chip 128. Note that the lead wires 127 and 129 and the temperature measuring units 130 and 132 have insulating coating layers, but are omitted in the drawing.

  The shaft body 122 is made of a metal material having relatively high rigidity, for example, Ni-Ti, brass, stainless steel, or aluminum. It is also possible to apply a polymer material having relatively high rigidity such as polyimide, vinyl chloride, or polycarbonate.

  The tube 136 and the sheath 150 are made of an insulating polymer material such as polyolefin, a crosslinked polyolefin, polyvinyl chloride, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, polyurethane elastomer, fluororesin, or polyimide. The As the polyolefin, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, and ionomer are applied. It is also possible to apply a mixture of the above polymer materials.

  The sheath 150 can also incorporate a reinforcement. The reinforcing body may have a mesh structure in which stainless steel is knitted, for example.

  When a guiding catheter is used, the raised portion 153 and the through hole 154 of the sheath 150 can be omitted as appropriate. If necessary, X-ray contrast markers made of an X-ray opaque material are appropriately disposed at a location indicating the position of the basket 124, a location indicating the positions of the first electrode chip 126 and the second electrode chip 128, or the like. It is also possible. The radiopaque material is, for example, platinum, gold, silver, titanium, or tungsten.

  Next, the hand operation part of an ablation catheter is demonstrated.

  FIG. 6 is a cross-sectional view for explaining the hand operating portion of the ablation catheter.

  The hand operation unit 160 includes a kink-resistant tube 161 and an operation main body 164 as shown in FIG.

  The kink resistant tube 161 has a through-hole 162 and is disposed at the tip of the operation main body 164. The through hole 162 is configured such that the proximal end portion 156 of the sheath 150 can be inserted. The kink resistant tube 161 has a function of preventing kinking (bending) of the sheath 150 in the vicinity of the distal end of the operation main body 164.

  The operation main body 164 is a part held by the operator, and includes a through hole 165, a connector 166, and a drive mechanism 170.

  The through hole 165 is configured such that the proximal end portion 156 of the sheath 150 can be inserted, is disposed at the distal end of the operation main body portion 164, and is aligned with the through hole 162 of the kink resistant tube 161. The through hole 165 cooperates with the through hole 162 and is used to introduce the proximal end portion 156 of the sheath 150 into the operation main body portion 164.

  The connector 166 includes a terminal 167 and a socket 168 and is disposed at the proximal end portion inside the operation main body 164, and the proximal end of the shaft main body 122 is fixed. The terminal 167 is connected to the lead wire 127 (first electrode chip 126), the lead wire 129 (second electrode chip 128), and the temperature measuring units 130 and 132. The socket 168 is configured such that the connector 182 of the first cable 184 extending from the energy supply device 180 is detachable.

  As described above, the drive mechanism 170 is provided to advance the sheath 150 toward the distal end and retract toward the proximal end, and is disposed inside the operation main body 164, and includes a moving member 172, a gear 174, and an operation member. 176 and an opening 178.

  The moving member 172 is slidably held, is connected to the proximal end portion 156 of the sheath 150, and has a tooth portion 173. The gear 174 is configured to fit with the tooth portion 173 of the moving member 172. That is, the moving member 172 and the gear 174 constitute a rack and pinion mechanism. Therefore, the moving member 172 moves forward with the proximal end portion 156 of the sheath 150 according to the rotation direction of the gear 174 and moves backward with respect to the distal end side. The moving distance of the moving member 172 is set so that the basket 124 and the deformed portion 134 where the first electrode tip 126 and the second electrode tip 128 are disposed protrude from the distal end portion 151 of the sheath 150 and are exposed. Yes.

  The operation member 176 is connected to the gear 174 and is used for rotationally driving the gear 174. The opening 178 is located above the operation member 176 and exposes the operation member 176 partially. Therefore, the surgeon can operate the operation member 176 with fingers or the like through the opening 178. Note that the shaft main body 122 of the shaft portion 120 extending inside the sheath 150 is not fixed to the moving member 172, passes through the inside of the moving member 172, and is fixed to the connector 166.

Thus, rotating the operation member 176 in a counterclockwise direction _{R 2,} the moving member 172 is retracted in the proximal direction _{M 1} and entrains the sheath 150. Since the position of the shaft portion 120 does not change, the distal end of the shaft portion 120 protrudes from the distal end portion 151 of the sheath 150, and the deformed portion 134 where the basket 124, the first electrode tip 126, and the second electrode tip 128 are disposed is exposed. In addition, the basket 124 is expanded. On the other hand, by rotating the operation member 176 in the clockwise direction _{R 1,} the moving member 172 is advanced distally _{M 2} to entrain the sheath 150. Also in this case, since the position of the shaft portion 120 does not change, the basket 124 and the deformable portion 134 are accommodated in the lumen 158 of the distal end portion 151 of the sheath 150, and the basket 124 contracts.

  For the kink resistant tube 161 and the operation main body 164, for example, a polymer material such as ABS resin, polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer is applied. It is also possible to apply a mixture of the above polymer materials.

  Next, an example of how to use the ablation system will be described.

  7A is a cross-sectional view for explaining insertion of a guide wire, FIG. 7B is a cross-sectional view for explaining insertion of a distal end portion of the ablation catheter, and FIG. 7C is an ablation catheter. It is sectional drawing for demonstrating retreat of the sheath of this, and expansion of a basket.

  First, the connector 182 of the first cable 184 of the energy supply device 180 is connected to the socket 168 of the operation main body 164 of the hand operation unit 160, and the counter electrode plate 188 connected to the second cable 186 of the energy supply device 180 is Affixed to the patient's body surface.

  An introducer sheath is attached percutaneously to the radial artery in the right or left hand. Then, as shown in FIG. 7A, a guide wire 190 is inserted into the radial artery via the introducer sheath, and from the radial artery to the brachial artery and the axillary artery, the inside of the renal artery 310 of the aorta 300 Are arranged at predetermined positions.

  Thereafter, the guide wire 190 is inserted into the through hole 154 of the sheath 150 of the ablation catheter 110. Then, the sheath 150 is introduced into the living body lumen along the guide wire 190, and the distal end portion 151 of the sheath 150 is guided to the inside of the renal artery 310, as shown in FIG. Is positioned in the vicinity of the wall tissue of the renal artery 310 adjacent to the renal sympathetic nerve 320. The guide wire 190 is then removed. The guide wire 190 can be introduced from a blood vessel other than the radial artery, for example, the brachial artery, the axillary artery or the femoral artery.

The operation member 176 of the operating main body portion 164 is rotated in a counterclockwise direction _{R 2} (see FIG. 6). As a result, the moving member 172 moves back in the proximal direction M ₁ with the sheath 150, and the distal end of the shaft portion 120 protrudes from the distal end portion 151 of the sheath 150. As a result, the basket 124 and the deformed portion 134 in which the first electrode chip 126 and the second electrode chip 128 are disposed are exposed.

  The basket 124 expands by protruding from the distal end portion 151 of the sheath 150, and comes into contact with the wall tissue of the renal artery 310 and is anchored as shown in FIG. 7C. Thereby, the shaft part 120 is fixed.

Thereafter, the hand operation unit 160 is operated such that the deforming portion 134 of the shaft portion 120 is pushed toward the distal end side. As a result, the deforming portion 134 is curved, and the curved region comes into contact with the renal artery 310. The first electrode tip 126 and the second electrode tip 128, when the curved region is in contact with the wall tissue of the renal artery 310, wall tissue _{T 1} of the renal artery 310 adjacent the renal sympathetic nerves 320 is the treatment target portion and _{T 2} (Refer to FIG. 4). As a result, a circuit is formed among the energy supply device 180, the first electrode chip 126 and the second electrode chip 128, the living body, and the counter electrode plate 188.

  At this time, the deformed portion 134 in which the first electrode tip 126 and the second electrode tip 128 are disposed is fixed to the distal end via the basket 124 anchored to the wall tissue of the renal artery 310. The occurrence of displacement of the first electrode chip 126 and the second electrode chip 128 is suppressed.

When a high-frequency current is supplied from the energy supply device 180, it flows into the living tissue via the first electrode chip 126 and the second electrode chip 128 and returns to the counter electrode plate 188. At this time, Joule heat is generated by resistance heating. Wall tissue T ₁ and T ₂ of the lumens is a contact surface of the first electrode tip 126 and the second electrode tip 128 and the body tissue, because the current concentrates, local temperature rise caused by Joule heat caused.

  For example, the high frequency is 350 to 750 kHz, the high frequency electric energy is 0.1 to 8.0 W, the heating temperature is 50 to 70 ° C., and the heating time is 30 to 60 seconds.

Thus, (fibers ablation and necrosis of the renal sympathetic 320) heat denaturation of the treatment target site adjacent to the wall tissue T ₁ and T ₂ of the lumen (renal sympathetic nerve 320 that runs around the renal artery 310) is prompted . In addition, in the basket 124, the wall tissue of the renal artery 310 that has been heat-denatured after the operation is cooled by blood in order to allow the body fluid to flow.

When the thermal denaturation of the treatment target site is completed, the supply of high-frequency current from the energy supply device 180 is stopped. Then, by stopping the pushing operation of the deformable section 134 of the shaft portion 120, the deformation portion 134, to return to a substantially straight line, and the first electrode tip 126 and the second electrode tip 128 wall tissue _{T 1} and _{T 2} The contact is eliminated. Further, by rotating the operation member 176 in the clockwise direction _{R 1,} the moving member 172 is advanced distally _{M 2} to entrain the sheath 150. As a result, the basket 124 and the deforming portion 134 are accommodated inside the lumen 158 of the distal end portion 151 of the sheath 150. As a result, the basket 124 contracts and the anchoring of the renal artery 310 to the wall tissue is eliminated.

  Thereafter, by operating the hand operation unit 160, the distal end portion 151 of the sheath 150 is appropriately moved and rotated and positioned near the next treatment target site. For example, the moving distance of the distal end portion 151 of the sheath 150 is 0.3 to 1.0 mm, and the rotation angle is 90 to 270 degrees.

  Then, the moving member 172 is retracted (the basket 124 is moored with respect to the wall tissue), the pushing operation of the deformable portion 134 (the contact of the first electrode tip 126 and the second electrode tip 128 with the wall tissue), the high frequency from the energy supply device 180. Start of supply of current, thermal denaturation of the treatment target site, stop of supply of high-frequency current, stop of pushing operation of the deforming part 134 (separation from the wall tissue of the first electrode tip 126 and the second electrode tip 128), and the movement member 172 Advancement (removal of the mooring of the basket 124 with respect to the wall tissue) is performed sequentially as well.

  Then, the above treatment is repeated as appropriate so that the heat-denatured portion draws a spiral on the inner wall surface of the renal artery 310. When the treatment is completed, the same treatment is repeated as appropriate for the renal artery 310 toward the other kidney 330.

  When the treatment of the right and left renal arteries 310 is completed, the ablation catheter 110 and the introducer sheath are removed, and the procedure ends. Only the left or right renal artery may be treated.

  Note that the movement and rotation of the distal end portion 151 of the sheath 150 is performed by thermally degenerating the renal sympathetic nerve 320 located outside the renal artery outer membrane and the outer membrane in a spatial manner around the renal artery 310. On the other hand, this is to prevent the entire circumference from being damaged in the cross section in the renal artery 310. This reduces the risk of vascular stenosis.

  Next, Modifications 1 to 4 according to Embodiment 1 will be sequentially described.

  FIG. 8A and FIG. 8B are schematic diagrams for explaining Modification 1 and Modification 2 according to Embodiment 1.

  The ablation catheter 110 is not limited to the form having two electrode tips. For example, as shown in FIG. 8A, one of the first electrode tip 126 and the second electrode tip 128 is omitted as necessary. Alternatively, as shown in FIG. 8B, the third electrode chip 140 can be disposed in the deformed portion 134.

  FIG. 8C is a schematic diagram for explaining the third modification according to the first embodiment.

  The expansion body is not limited to the form constituted by the self-expanding basket 124, and a self-expanding snare 142 can be applied as shown in FIG. 8B. Also in this case, since the circulation of the body fluid is allowed, interference with the cooling effect of the body fluid is suppressed.

  FIG. 9A and FIG. 9B are cross-sectional views for explaining the hand operating portion and the sheath of Modification 4 according to Embodiment 1.

  The ablation catheter 110 is not limited to the rapid exchange (RX) type, but is an over-the-wire (OTW) type having a lumen 144, a port 146 and a communication passage 148, as shown in FIGS. 9 (A) and 9 (B). It is also possible to apply.

  The lumen 144 is provided on the sheath 150 and communicates with the distal end portion 151. The port 146 is disposed in the operation main body 164 of the hand operation unit 160 and is used to introduce the guide wire 190 into the operation main body 164. The communication path 148 connects the port 146 and the lumen 144.

  Therefore, the guide wire 190 passes through the port 146, the communication path 148 and the lumen 144, and is led out from the distal end portion 151 of the sheath 150. That is, in this case, since the guide wire 190 has a structure that passes from the tip to the hand, the guide wire can be exchanged and operated easily.

  As described above, in the first embodiment, heat denaturation is performed by applying energy to the wall tissue of the lumen, which is the treatment target site in the diseased part, by the thermal element (first electrode chip and second electrode chip). In this case, the deformable portion can be fixed via an expansion body (basket) that is anchored to the wall tissue of the lumen. In this case, since the thermal element is disposed in the curved region of the deforming portion, occurrence of positional deviation is suppressed. That is, it is possible to provide an ablation catheter that can suppress the displacement of the thermal element. Further, since the expansion body is constituted by a basket or snare that allows the body fluid to flow, interference with the cooling effect of the body fluid is suppressed when the wall tissue of the lumen that has been heat-denatured after the operation is cooled by the body fluid. .

  Next, a second embodiment will be described.

  10A is a schematic diagram for explaining the ablation catheter according to Embodiment 2, and FIG. 10B is a cross-sectional view taken along line X (B) -X (B) in FIG. FIG. 11 is a cross-sectional view for explaining the shaft tip shown in FIG. 10, and FIG. 12 is a cross-sectional view for explaining the operation of the balloon shown in FIG.

  The second embodiment is generally different from the first embodiment in that it is an over-the-wire (OTW) type, does not have a sheath and a sheath drive mechanism, and has a configuration of an expansion body. In the following, members having the same functions as those of the first embodiment are denoted by similar reference numerals, and the description thereof is omitted to avoid duplication.

  As shown in FIG. 10A, the ablation catheter 210 according to the second embodiment includes a shaft portion 220 and a hand operation portion 260.

  The shaft portion 220 includes a shaft main body 222, a balloon 224 that can be expanded and contracted, a first electrode tip 226, a second electrode tip 228, temperature measuring portions 230 and 232, a deformation portion 234, a tube 236, a lumen 238, and an inflation port 240. And an expansion lumen 242.

  The shaft body 222 is a long tubular body, and has a lumen 244 as shown in FIGS. 10 (B) and 11. The lumen 244 is for the guide wire 290 and extends from the distal end of the shaft body 222 toward the proximal end. In FIG. 10B, reference numeral 227 denotes a lead wire used for supplying the first electrode chip 226 with a high-frequency current from the energy supply device, and reference numeral 229 denotes a high-frequency current from the energy supply device. The lead wire used for supplying the second electrode chip 228 to the second electrode chip 228 is shown. Reference numeral 235A denotes a curved region, and reference numeral 235B denotes a curved support region.

  The balloon 224 is disposed at the distal end portion of the shaft body 222 and is configured to come into contact with the wall tissue of the renal artery 310 by expanding as shown in FIG. Therefore, since the balloon 224 is expanded and anchored to the wall tissue of the renal artery 310, the distal end portion of the shaft portion 220 can be fixed to the wall tissue of the renal artery 310. At this time, since the balloon 224 is anchored in contact with the entire inner wall of the renal artery 310, the deformed portion 234 is fixed in the axial direction, the circumferential direction, and the radial direction of the renal artery 310, and the center of the renal artery 310 is fixed. Is positioned. Therefore, it is possible to satisfactorily suppress the displacement of the first electrode chip 226 and the second electrode chip 228.

  Inflation port 240 (see FIG. 10A) is used to introduce and expel pressurized fluid that causes balloon 224 to expand. The pressurized fluid is, for example, a liquid such as physiological saline or an angiographic contrast agent. The installation position of the inflation port 240 is not particularly limited.

  The expansion lumen 242 connects the inflation port 240 and the balloon 224. Therefore, the inflation port 240 and the balloon 224 are in communication.

  For the balloon 224, for example, polyolefin such as polyolefin, polyvinyl chloride, polyamide elastomer, polyurethane, polyester such as polyethylene terephthalate, polyarylene sulfide such as polyphenylene sulfide, silicone rubber, and latex rubber are applied. The polyolefin is, for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, or cross-linked ethylene-vinyl acetate copolymer.

  The hand operation unit 260 includes a kink resistant tube 261 and an operation main body 264 (see FIG. 10A). The operation main body 264 includes a connector 266, a port 246, and a communication path (not shown).

  The port 246 is used to introduce the guide wire 290 into the operation main body 264. The communication path 248 connects the port 246 and the lumen 244. Accordingly, the guide wire 290 can pass through the port 246, the communication path 248, and the lumen 244 and be led out from the tip of the shaft portion 220.

  As described above, the ablation catheter 210 can fix the deformed portion 234 via the balloon 224 anchored to the wall tissue of the renal artery 310 (see FIG. 12). Therefore, the occurrence of misalignment between the first electrode chip 226 and the second electrode chip 228 disposed in the deforming portion 234 is suppressed.

  The ablation catheter 210 is not limited to the over-the-wire (OTW) type, and a rapid exchange (RX) type (see FIG. 2) can also be applied.

  Next, Modification 1 according to Embodiment 2 will be described.

  FIG. 13A is a schematic diagram for explaining Modification Example 1 according to Embodiment 2, and FIG. 13B is a cross-sectional view taken along line XIII (B) -XIII (B) in FIG. FIG. 14 is a cross-sectional view for explaining the shaft front end portion shown in FIG.

  The ablation catheter 210 is not limited to a configuration having a port 246, a communication path 248, and a lumen 244 used for insertion of the guide wire 290. For example, when a guiding catheter is used, as shown in FIGS. 13A and 13B, the port 246, the communication path 248, and the lumen 244 can be omitted as appropriate.

  In this case, since the lumen 244 is not formed in the shaft main body 222 and is solid, the diameter thereof can be reduced. For example, as shown in FIG. 14, the balloon 224 is attached with a flexible tip protrusion 225 that is used for pushing.

  As described above, also in the second embodiment, it is possible to provide an ablation catheter that can suppress the displacement of the thermal elements (the first electrode tip and the second electrode tip). The expansion body is constituted by a balloon that can be expanded and contracted, and is anchored in contact with the entire inner wall. Therefore, the expansion body is fixed with respect to the axial direction, the circumferential direction, and the radial direction of the lumen, and the deformed portion is fixed to the lumen. Positioned in the center. Therefore, it is possible to satisfactorily suppress the displacement of the thermal elements (first electrode chip and second electrode chip).

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims.

  For example, the energy applied by the heat element is not limited to a form using resistance heating by high-frequency energization, and coherent light such as cooling, microwave, ultrasonic wave, laser, or the like can be used.

  Resistance heating by high-frequency energization is not limited to a form using a monopolar electrode and a counter electrode plate, and a bipolar electrode can also be applied.

  The treatment target region is not limited to the renal artery, and can be applied to myocardial cauterization for treating tachyarrhythmia.

  The use of ablation catheters is not limited to treatment aimed at lowering blood pressure in patients with refractory hypertension; heart failure, renal disease, chronic renal failure, sympathetic hyperactivity, diabetes, metabolic disorders, arrhythmia, acute myocardial infarction, cardiorenal It can also be applied to the treatment of syndromes and the like.

100 ablation system,
110,210 Ablation catheter,
120, 220 shaft part,
122,222 shaft body,
124 basket (expanded body),
125,225 tip protrusion,
126, 226 First electrode tip (thermal element),
127, 227 lead wire,
128,228 second electrode chip (thermal element),
129, 229, lead wires,
130, 132, 230, 232 temperature measuring unit,
134, 234 deformation part,
135A, 235A curved region,
135B, 235B curved support area,
136,236 tubes,
138,238 lumens,
140 Third electrode chip (thermal element),
142 snare (expanded body),
144,244 lumens,
146,246 ports,
148 communication path,
150 sheath,
151 tip,
153 ridges,
154 through-hole,
156 proximal end,
158 lumens,
160,260 Hand control unit,
161,261 kink tube,
162 through-holes,
164,264 operation main body,
165 through-hole,
166,266 connector,
167 terminal,
168 socket,
170 drive mechanism,
172 moving member,
173 teeth,
174 gears,
176 operation member,
178 opening,
180 energy supply device,
182 connector,
184 first cable,
186 second cable,
188 counter electrode,
190,290 guide wire,
224 balloon,
240 inflation port,
242 expansion lumen,
300 aorta,
310 renal artery,
320 Renal sympathetic nerve,
330 kidney,
M ₁ proximal direction,
M ₂ tip direction,
T ₁ , T ₂ wall tissue,
R ₁ clockwise direction,
R ₂ counterclockwise direction.

Claims (6)

An ablation catheter having a shaft portion inserted into a lumen in a living body,
The shaft portion is
Expansion body capable of expansion and contraction,
At least one thermal element that thermally affects biological tissue; and
It has a deformation part located on the base end side from the expansion body,
The deformable portion has a curved region that is curved and contacts the wall tissue of the lumen in a state where the expansion body is expanded and anchored to the wall tissue of the lumen.
The thermal element is disposed in the curved region ;
The deformation part has a curved support region extending from both ends of the curved region,
The curved region has more flexibility or stretchability than the curved support region,
The ablation catheter , wherein the thermal element is annular and is disposed so as to cover an outer periphery of the curved region . The deforming portion has at least three or more curved support regions,
The ablation catheter according to claim 1 , wherein the curved region and the curved support region are alternately arranged. 2. The ablation according to claim 1, wherein the deformable portion is curved when the shaft portion is pushed toward a distal end side in a state where the expansion body is expanded and anchored to a wall tissue of the lumen. catheter. It said thermal element, the ablation catheter according to any one of claims 1 to 3, characterized in that it consists of monopolar electrode. The ablation catheter according to any one of claims 1 to 4 , wherein the expansion body is three-dimensionally formed of a wire material having self-expandability and elasticity. The ablation catheter according to any one of claims 1 to 5 , wherein the expansion body includes an expandable and contractible balloon disposed so as to cover an outer periphery of the shaft portion.