JP6570181B2 - Catheter and catheter system - Google Patents

Description

The present invention relates to a catheter and a catheter system, and more particularly to a catheter and a catheter system for stimulating tissue in the body and a catheter and a catheter system used for detecting information on the tissue in the body. The catheter described in the present application refers to a long member that is inserted into a living body lumen and used for treatment of the affected area or measurement of the affected area, and the catheter system refers to a long cylindrical member that penetrates the long member. An overall configuration including a treatment device including a sheath, an operating means connected to the sheath, an operation means for moving the sheath, a treatment tool, and an electric device for driving the measurement tool.

Examples of catheters and catheter systems that provide stimulation to tissue in the body include those used for ablation treatment. This ablation is a technique for blocking nerves by destroying nerve cells in the target tissue by heating or cooling the target tissue. In recent years, the target tissue is heated by irradiation with high frequency, ultrasonic waves, radio waves, laser light, infrared rays, etc., and a heating element for treatment resistant hypertension or cardiac tachyarrhythmia. On the other hand, ablation treatment with low temperature cooling is performed. For example, 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, in Patent Document 1, a tip shape of an ablation catheter is formed in a spiral shape, a ring electrode is attached to the spiral portion, and the guide wire is guided through holes provided on the proximal side and the distal end side from the spiral portion. Describes a catheter that treats the affected area with the tip of the catheter reaching the affected area with the guide wire removed from the hole. This ablation catheter has a structure in which the guide wire does not pass through the spiral portion by passing the guide wire through two holes on the proximal side and the distal end side from the spiral portion, so that the outer diameter of the spiral portion does not have to be increased. It has become.

JP 2014-180556 A

However, as in the ablation catheter described in Patent Document 1, when the distal end of the catheter is formed in a spiral shape, a portion that is turned in a coil shape is easily crushed in the tube during the operation, and thus the shape of the ablation catheter tends to collapse. In the case of the bipolar type, the spiral portion is crushed in the tube and its shape collapses, so that there is a risk that a plurality of electrodes are brought into contact with each other and short-circuited.

An object of the present invention has been made in view of such a situation, and a catheter capable of appropriately bringing a stimulus applying means provided on a catheter into contact with a target site while preventing the shape from being deformed during a treatment or the like. And providing a catheter system.

In order to achieve the above-mentioned object , the present invention provides a long catheter main body in which a spiral portion, which is a spirally wound contact means in contact with a plurality of locations on the inner wall of a living body lumen, is formed on the distal end side. A catheter operating part for operating the catheter body;
At least one or more stimulation-applying means disposed on the spiral contact means for stimulating tissue in the body;
Wherein disposed at the distal end of the catheter body, it expands the distal end of the catheter body with a larger diameter than the inner diameter of the body tube lumen by inflow of the fluid to be held at a position spaced from the inner wall of the body lumen A balloon which can be deflated by suction of fluid ;
With
The catheter main body has a linear portion that is linear so as to be substantially on the central axis of the spiral on the catheter operation portion side of the spiral contact means, and a spiral portion on the distal end side of the spiral contact means. An extension portion extending linearly on the substantially central axis is formed,
The balloon is attached to the linearly extending extension part, and the expansion center axis and the spiral center axis of the contact means are matched,
The spiral contact means, as a symmetrical around the outer edge expansion central axis in contact with the plurality of locations of the inner wall of the living body lumen when the balloon is inflated to a large diameter than the inner diameter of the body tube lumen The first feature is that the shape is stored in advance so as to expand spirally in a parallel state, deforms when an external force is applied, and returns to the previously stored shape when the external force is removed.

In the catheter according to the first feature, the present invention has a second feature that the stimulus applying means is an electrode for applying a current to the inner wall of the living body lumen, and the second feature. In the catheter described in (2), the electrode is a bipolar system in which a positive electrode and a negative electrode are arranged with an insulating material interposed in one electrode, and current is passed between the two electrodes of the positive electrode and the negative electrode. The catheter according to any one of the above characteristics is characterized in that the number of the stimulus applying means is 5 to 8 per one spiral of the spiral contact means.

Further, the present invention provides the catheter according to any one of the above features, further comprising an elongated shaft portion connected to the balloon for driving the balloon, wherein the cartel body and the shaft portion are the catheter. It is inserted through a hole formed in the longitudinal direction of the operation part, and either one of the catheter body or the shaft part is fixed to the hole of the catheter operation part, and the other is movable in the hole. The catheter according to the fifth feature is provided with a lock mechanism for fixing and releasing the catheter body or the shaft portion movable in the hole to the catheter operation portion. 6. The catheter according to any one of the above-mentioned features, wherein the catheter body and the balloon are stored inside and outside from the distal end side. And seventh aspect by comprising an elongated and hollow sheath can be exposed to.

The catheter and the catheter system according to the present invention hold the distal end of a long catheter body in which a spiral contact means that contacts a plurality of locations on the inner wall of the living body lumen is formed on the distal end side at a position away from the inner wall of the living body lumen. By providing a balloon that is a means for performing the operation, the distal end of the catheter body is held at a position away from the inner wall of the living body lumen at the time of treatment, etc. The provided stimulus applying means can be appropriately brought into contact with the target site, and the tip of the catheter body can be prevented from being caught on the inner wall of the living body lumen.

1 is an overall view of an ablation catheter system according to an embodiment of the present invention. The enlarged view which shows the front-end | tip of an ablation catheter. The enlarged view which shows the front-end | tip at the time of the operation of an ablation catheter. The figure explaining insertion of the ablation catheter to a renal artery. The figure explaining an electrode of a bipolar type and a monopolar type. The figure explaining use and accommodation of an ablation catheter. The figure explaining an ablation catheter and a catheter guide. The enlarged view of a catheter operation part.

Hereinafter, an embodiment when the catheter and the catheter system according to the present invention are applied to an ablation catheter and a temperature sensor catheter arranged in the esophagus will be described. First, an embodiment when the present invention is applied to an ablation catheter will be described. To do. In addition, the catheter and catheter system according to the present invention can be applied other than the ablation described in the embodiment, for example, in the treatment of cancer such as the liver, a heating medium is introduced while monitoring the temperature of the tube wall, In the heat treatment to bring cancer tissue to apoptosis, and to heat and treat the prostate, the extension equipped with a temperature sensor and a cooling tube is applied to the wall, intensively heat treating the prostate while protecting the inner surface of the urethra It can be applied widely such as prostate treatment to contract.

[Configuration] The ablation catheter 2 to which the catheter according to the present embodiment is applied is a catheter for ablating the renal sympathetic nerve RN from the inside of the renal artery RA, as shown in FIG. The ablation is performed by cauterizing the target tissue by supplying high-frequency waves or the like to the electrodes which are inserted into the renal artery RA through the electrodes and serving as stimulation applying means provided at the distal end of the ablation catheter 2.

As shown in FIGS. 1, 2, and 7, the ablation catheter system 1 is roughly divided into long ablation in which an electrode 28 for heating a target tissue is arranged at the tip as a stimulus applying means for applying a stimulus to a tissue in the body. A catheter 2 and a catheter guide 3 are provided for guiding the long ablation catheter 2 inside the long cylinder and guiding the electrode 28 attached to the distal end of the ablation catheter 2 to the target tissue.

[Description of Ablation Catheter 2] As shown in FIGS. 1 and 7, the ablation catheter 2 is formed in a coil shape that is a contact portion that contacts a plurality of locations on the inner wall of a living body lumen (in this embodiment, the renal artery RA). A catheter main body 21 in which an electric wire is routed inside a long cylindrical shape in which a spiral part 21a is formed on the distal end side, a catheter operation part 23 for operating the catheter main body 21, and a distal end of the spiral part 21a The inflatable and inflatable balloon 24 serving as the holding means and a hollow shaft portion 27 for supplying fluid to the balloon 24 and driving it. The spiral portion 21a is also called a “spiral contact means” because it is a spiral contact portion. The ablation catheter 2 supplies a fluid to the balloon 24 from the fluid supply device 40 via the shaft portion 27 to be inflated and contracted. A high frequency current is supplied to the electrode 28 provided in the spiral portion 21a. In the present embodiment, the energy supplied to the electrode 28 is a high-frequency current, but is not limited thereto, and may be, for example, an ultrasonic wave, a radio wave, a laser beam, an infrared ray, or the like.

The catheter body 21 of the ablation catheter 2 is a flexible and hollow long shape, and forms a spiral portion 21a wound in a coil shape at the tip. As shown in FIG. 2, the spiral portion 21 a is a heating portion for performing ablation, and a plurality of electrodes 28 are arranged on the outside of the spiral shape, and an electric wire disposed inside the catheter body 21 from the high-frequency power source 25. A high frequency current is supplied via The number of the electrodes 28 is preferably about 20 as a whole, and preferably 5 to 8 per one spiral, and the distance between the electrodes 28 is preferably about 3 mm.

The spiral portion 21a is preliminarily stored in a spiral shape, deformed when an external force is applied, and returns to the previously stored shape when the external force is removed. Further, since the spiral portion 21a is coiled, the spiral portion 21a can be accommodated with a reduced diameter in the sheath 31, and when the spiral portion 21a is removed from the sheath, the spiral portion 21a expands to a predetermined diameter. Can be stored. Further, as shown in FIG. 2, the spiral portion 21a includes a straight portion 21b and a distal end side (catheter body) that are straight so that the proximal end side (catheter operation portion 23 side) of the spiral portion is on the substantially central axis of the spiral. 21 on the side to which the balloon 24 is attached) has an extending portion 21c that linearly extends on a substantially central axis of the spiral. The spiral portion 21a is placed in the renal artery RA and protrudes from the sheath 31 by shape memory molding so that the outer diameter L3 in a state where no external force can be applied is slightly larger than the inner diameter L4 of the renal artery RA. The electrode 28 can be brought into close contact with the inner wall of the renal artery RA. Further, when stored in the sheath 31 of the catheter guide 3, the catheter guide 3 is crushed by the inner wall of the sheath 31 so as to be equal to or less than the inner diameter L <b> 1 of the sheath 31, and becomes an elongated state.

In the present embodiment, the spiral portion 21a is formed at the distal end of the catheter main body 21. However, the spiral portion 21a is not limited to the spiral shape, and at least the contact portion may be configured to contact a plurality of locations on the inner wall of the living body lumen. Good. In the present embodiment, the electrode 28 is provided only on the spiral portion 21a. However, the present invention is not limited to this. For example, the electrode 28 may be provided at the tip of the extending portion 21c.

The extension portion 21c extending from the spiral portion 21a toward the distal end side is inflated in a cylindrical living body lumen (in this embodiment, the renal artery RA), thereby being separated from the inner wall of the living body lumen ( A balloon 24 for holding the extended portion 21c, which is the tip of the catheter body 21, is attached to a substantially extended line of the central axis of the spiral of the spiral portion 21a. The balloon 24 can be inflated and contracted in a substantially bag shape, and is inflated by a fluid such as air supplied from the tip of the shaft portion 27 through the hollow shaft portion 27 from the fluid supply device 40 to suck the fluid. Shrink due to The diameter of the balloon 24 can be set arbitrarily depending on the amount of fluid to be supplied, but as shown in FIG. 3, the diameter L2 at the time of ablation in the renal artery RA is expanded slightly larger than the diameter L4 of the renal artery RA. Accordingly, the spiral portion 21a is prevented from being excessively compressed and deformed by the renal artery RA, and the balloon 24 is fixed to the renal artery RA to make it difficult to shift the contact position of the electrode 28 provided on the spiral portion 21a.

As shown in FIG. 8, the shaft portion 27 is slidable in the axial direction in the catheter operation portion 23 by being inserted into the hole 23 e formed in the catheter operation portion 23 without being fixed. The protrusion amount from the catheter operation part 23 can be adjusted in accordance with the change in the shape of the spiral part 21a of the catheter body 21 fixed in the hole 23f of the operation part 23. The adjustment of the protrusion amount is preferably performed by the pin 23b fixed to the shaft portion 27, the lateral groove 23c cut out in the longitudinal direction of the catheter operation portion 23 so that the pin 23b can be moved, and the pin 23b. For example, when the spiral portion 21a is in the sheath 31, the pin 23b is inserted into the lock groove on the distal end side. When the spiral portion 21a is projected from the distal end of the sheath 31, the pin 23b is unlocked and moved along the lateral groove 23c. When the spiral portion 21a has the maximum diameter, the pin 23b is moved to the proximal side. It is performed by selecting the lock groove 23a according to the diameter of the spiral portion 21a, such as being positioned in the lock groove 23a.

The shaft portion 27 is provided with a pilot balloon 50 that expands and contracts in conjunction with the expansion and contraction of the balloon 24 and a valve 51 that adjusts the supply amount of fluid. Since it expands and contracts in conjunction with 24, it is easy to determine how much the balloon 24 has expanded and contracted. In the present embodiment, the catheter body 21 is fixed to the catheter operation section 23 and the shaft section 27 is not fixed. Conversely, the catheter body 21 is not fixed and the shaft section 27 is fixed. good. In addition, the shaft portion 27 is not limited to the above, and may be configured to be bonded adjacent to the catheter main body 21 in a state in which the shaft portion 27 is bent to allow the shape change of the spiral portion 21a, for example. Alternatively, a configuration may be adopted in which a fluid supply path is provided in the catheter body to supply fluid to the balloon.

In the present embodiment, the example in which the balloon 24 that is inflated and contracted by the fluid supply is provided as the holding means has been described. However, the present invention is not limited to this. For example, a wire that can be expanded and contracted may be formed into a box shape that is formed into a box shape that can be contracted and expanded. The dimensions L1 to L5 vary depending on the size of the body tube to be applied. For example, in the case of the renal artery RA of this embodiment, L1 is 3 to 4 mm, L2 is 6 to 10 mm, L3 is 6 to 10 mm, L4 can be 5 to 10 mm, and L5 can be 6 to 12 mm.

[Description of Catheter Guide 3] As shown in FIGS. 1 and 7, the catheter guide 3 includes a guide operation portion 34 and a hollow sheath 31 extending along the central axis, and is provided in the guide operation portion 34. By turning the guide bending dial 33, the bending portion 31a which is a flexible portion on the distal end side of the sheath 31 can be bent. In addition, a hole 34 a is formed in the guide operation portion 34 in the longitudinal direction so as to communicate with the sheath 31, and the catheter main body 21 of the ablation catheter 2 can be inserted, and the distal end of the ablation catheter 2 can be inserted from the distal end side of the sheath 31. It is possible to sink the side.

Although the structure for bending the bending portion 31a of the catheter guide 3 is not shown, for example, a hole is formed in the longitudinal direction of the sheath 31, a wire is disposed in the hole, and the distal end of the wire is fixed to the distal end of the sheath 31. The base end of the wire is wound around a pulley fixed coaxially with the bending dial 33, and the guide bending dial 33 is rotated to pull the wire, whereby the bending portion 31a is placed on the side where the pulled wire is disposed. Can be curved.

In the present embodiment, an example in which the ablation catheter 2 and the catheter guide 3 are combined has been shown. However, the present invention is not limited to this as long as the affected part can be reached in a state of covering the spiral portion 21a. 3 is provided directly on the ablation catheter without covering the catheter body, and by changing the relative position in the longitudinal direction between the sheath and the catheter body by operating the operation unit, The distal end side of the catheter main body may protrude and retract.

[Description of Use and Storage of Ablation Catheter System 1] Next, an example of a method for using the ablation catheter and the ablation catheter system according to the present embodiment will be described with reference to FIGS. First, as shown in FIG. 4, the catheter guide 3 is inserted from the brachial artery or the like with the ablation catheter 2 in a state in which the balloon 24 is deflated being accommodated inside the catheter guide 3, and the catheter guide 3 passes through the aorta A. The distal end of is reached to an arbitrary position inside the renal artery RA (for example, a position before the affected area). Next, as shown in FIG. 6A, from the state where the distal end side of the ablation catheter 3 is housed in the sheath 31, only the balloon 24 is protruded into the renal artery RA as shown in FIG. 6B. At this time, the balloon 24 may be inflated to such an extent that it does not get caught in the renal artery RA.

Then, as shown in FIG. 6C, by supplying a fluid to the balloon 24 via the shaft portion 27, the diameter L2 of the balloon 24 is inflated larger than the diameter L4 of the renal artery RA, and the position of the balloon 24 is fixed. Then, the sheath 31 is pulled, and the spiral portion 21a is projected as shown in FIG. At this time, since the spiral portion 21a is released from the radial compressive force caused by the inner wall of the sheath 31, the spiral portion 21a returns to a previously stored shape, and the outer diameter L3 of the spiral portion 21a is slightly smaller than the diameter L4 of the renal artery RA. Therefore, the electrode 28 can be reliably brought into contact with the renal artery.

Then, a current is supplied to the electrode 28 from the high-frequency power supply 25 via an electric wire disposed inside the catheter body 21 to heat the living tissue near the electrode 28. Thereby, for example, necrosis or thermal alteration can be caused in the fiber of the renal sympathetic nerve RN located in the vicinity of the electrode 28. At this time, if the balloon 24 is contracted so as to be approximately the same as or slightly smaller than the diameter L4 of the renal artery RA and the catheter body 21 is moved back and forth in the longitudinal direction, the balloon can be appropriately slid and the electrode 28 is disposed. Heating can also be performed between the spirals of the spiral portion 21a that is not. In the present embodiment, all the electrodes 28 are energized, and when the range of the affected part is short, adjustment is made by shortening the protruding amount of the spiral part 21a from the sheath 31, but not limited thereto. For example, a configuration may be adopted in which energization is selectively performed such that only one-half of the tip side of the plurality of electrodes 28 or only one-fourth.

After the ablation, as shown in FIG. 6 (e), the outer diameter of the balloon 24 is expanded to a diameter L4 larger than the diameter L4 at the time of ablation and the diameter L3 of the spiral portion 21a, and more firmly in the renal artery RA. In this state, the catheter body 21 is pulled toward the operation section 23 and the sheath 31 is pushed out. By doing so, a gap is formed between the renal artery RA and the spiral portion 21a, and the spiral portion 21a is stretched to reduce its diameter and can be easily accommodated in the sheath 31. Thereafter, the fluid in the balloon 24 is sucked through the shaft portion 27, accommodated in the sheath 31, and the ablation catheter 2 and the catheter guide 3 are discharged out of the body.

As described above, by disposing and inflating the balloon 24 at the distal end of the spiral portion 21a, the spiral portion 21a can be easily maintained at the target position, and it becomes difficult to receive the compressive force due to the renal artery RA. The spiral shape is unlikely to collapse, and the electrode 28 can be reliably applied to the inner wall surface. Further, by inflating the balloon 24 to some extent, it is safe that the tip does not swing up and down and right and left and is not caught on the inner wall surface when protruding from the sheath 31 and moving within the renal artery RA. Moreover, since the spiral part 21a can be reached to the affected part in the state accommodated in the sheath 31, it can be safely moved without damaging the inside of the body vessel.

When the range of the affected area in the renal artery RA is wide or extends to a plurality of locations, the spiral portion 21a and the balloon 24 are moved in a state where they are accommodated in the sheath 31 each time one-site treatment is completed, and again shown in FIG. By repeating the steps a) to (e), a safe treatment can be performed. As long as the electrode 28 is not energized, the spiral portion 21a may be moved to another location while the balloon 24 is deflated so that it slightly contacts the renal artery RA.

[Description of Electrode Applied to Ablation Catheter System 1] As shown in FIG. 5 (a), the electrode 28 provided in the ablation catheter 2 according to the present embodiment includes a positive electrode 90 and a negative electrode so as to form a pair in one electrode. It is also possible to ablate the affected area by a bipolar system in which 91 is arranged and energized with an insulating material 93 interposed between them, and as shown in FIG. The affected area can be ablated by a monopolar system in which electricity is applied to the patient's opposite surface. In the present embodiment, an electrode using a high frequency will be described. However, the present invention is not limited to this. For example, a microwave may be used.

In this embodiment, a plurality of electrodes 28 are provided. In the case of the monopolar system, the electrodes that are paired with the electrodes are counter electrodes attached to the opposite surface of the patient. However, when the bipolar method is used, if the electrodes 28 come into contact with each other, they are short-circuited and cannot be brought into contact with each other. In this regard, according to the present embodiment, the balloon 24 is provided on the distal end side from the spiral portion 21a and inflated, so that the shape of the spiral portion 21a is crushed by the compressive force of the renal artery RA. The electrodes 28 are not in contact with each other and are safe.

1 ablation catheter system, 2 ablation catheter, 3 catheter guide, 21 catheter body, 21a spiral part, 23 catheter operation part, 24 balloon, 27 shaft part, 28 electrodes, 31 sheath, 31a bending part

Claims (7)

A spiral portion, which is a spirally wound contact means that contacts a plurality of locations on the inner wall of a living body lumen, is provided on a long catheter body formed on the distal end side and a proximal end side, for operating the catheter body A catheter operating section;
At least one or more stimulation-applying means disposed on the spiral contact means for stimulating tissue in the body;
Wherein disposed at the distal end of the catheter body, it expands the distal end of the catheter body with a larger diameter than the inner diameter of the body tube lumen by inflow of the fluid to be held at a position spaced from the inner wall of the body lumen A balloon which can be deflated by suction of fluid ;
With
The catheter main body has a linear portion that is linear so as to be substantially on the central axis of the spiral on the catheter operation portion side of the spiral contact means, and a spiral portion on the distal end side of the spiral contact means. An extension portion extending linearly on the substantially central axis is formed,
The balloon is attached to the linearly extending extension part, and the expansion center axis and the spiral center axis of the contact means are matched,
The spiral contact means, as a symmetrical around the outer edge expansion central axis in contact with the plurality of locations of the inner wall of the living body lumen when the balloon is inflated to a large diameter than the inner diameter of the body tube lumen A catheter that is preliminarily memorized so as to expand spirally in a parallel state, deforms when an external force is applied, and returns to a prestored shape when the external force is removed. The catheter according to claim 1 ,
The catheter, wherein the stimulus applying means is an electrode for applying an electric current to the inner wall of the living body lumen. A catheter according to claim 2 ,
The catheter is a bipolar system in which a positive electrode and a negative electrode are arranged with an insulating material interposed in one electrode, and current is passed between the two electrodes of the positive electrode and the negative electrode. The catheter according to any one of claims 1 to 3 ,
5. The catheter according to claim 1, wherein the number of the stimulus applying means is 5 to 8 per one spiral of the spiral contact means. The catheter according to any one of claims 1 to 4 ,
A long shaft portion connected to the balloon for driving the balloon;
The cartel body and the shaft part are inserted through a hole formed in the longitudinal direction of the catheter operation part,
One of the catheter main body and the shaft portion is fixed to the hole of the catheter operation portion, and the other is movable in the hole. A catheter according to claim 5 ,
A catheter comprising a locking mechanism for fixing and releasing the catheter main body or the shaft portion movable in the hole to the catheter operation portion. A catheter according to any of claims 1 to 6 ;
A catheter system comprising an elongated and hollow sheath capable of accommodating the catheter body and the balloon from the distal end side inside and exposing the catheter body and the balloon to the outside.

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