JP2021010455A - Balloon catheter and operation method thereof - Google Patents

Abstract

To provide a balloon catheter capable of preventing excessive insertion of a balloon for cautery into a pulmonary vein, and an operation method thereof.SOLUTION: A balloon catheter 1 includes a shaft 10 extending in a far-near direction, a first balloon 21 provided on a distal side of the shaft 10, and a second balloon 22 provided in the first balloon 21. The first balloon 21 and the second balloon 22 are fixed to each other in a first section 25 from a distal end of a non-fixed part 22c of the second balloon 22 to a predetermined position more distal than a proximal end of the non-fixed part 22c of the second balloon 22, and in the first section 25, at least part of an inner surface of the first balloon 21 abuts against an outer surface of the second balloon 22.SELECTED DRAWING: Figure 1

Description

The present invention relates to a balloon catheter and a method of operating the balloon catheter, and more particularly to a balloon catheter capable of cauterizing body tissue.

In pulmonary vein isolation for the treatment of atrial fibrillation, a catheter with a balloon (ablation catheter) is used. For example, a balloon of a balloon catheter is placed in the pulmonary vein opening, and a mixture of physiological saline and a contrast medium is injected into the balloon to inflate the balloon so that the balloon is brought into close contact with the pulmonary vein opening, and then the balloon is used. By heating the mixture in the pulmonary vein, the tissue at the opening of the pulmonary vein is heated and cauterized. In such a catheter, it has been proposed to provide a plurality of balloons in order to increase the heating efficiency or cauterize only a desired position (for example, Patent Documents 1 and 2).

Patent Document 1 discloses that in a balloon catheter having an outer balloon and an inner balloon, the outer balloon is filled with a gas having low thermal conductivity, and the filling liquid filled inside the inner balloon is heated at high frequency. .. It is also disclosed that the outer balloon maintains its position in the luminal organ and blocks the heat conduction of the inner balloon, and the heat energy of the inner balloon selectively irradiates the target tissue through the contact portion with the outer balloon. Has been done.

In Patent Document 2, in a balloon catheter in which the inside of the balloon is divided into a front space and a rear space and a diaphragm through which the catheter shaft penetrates is provided, the heating means is provided in either or both of the front space and the rear space. It is disclosed that it will be distributed. According to such a balloon catheter, it is disclosed that the time required to reach a temperature at which cauterization is possible with good heating efficiency can be shortened, and that cauterization can be prevented from a site other than the desired site to be cauterized. ing.

Japanese Unexamined Patent Publication No. 2013-132364 Japanese Unexamined Patent Publication No. 2006-239234

However, a cauterizing balloon may be over-inserted into the pulmonary vein by the surgeon pushing the catheter too far in order to make the balloon as close as possible to the pulmonary vein opening. As a result, the vascular tissue in the pulmonary veins may be cauterized, causing pulmonary vein stenosis, and excessive heat may be transferred to the esophagus, which is in a positional relationship close to the pulmonary veins, resulting in esophageal ulcer. Alternatively, there was a problem such as thrombus due to retention of blood flow, and there was room for improvement. Therefore, an object of the present invention is to provide a balloon catheter capable of preventing over-insertion of a cautery balloon into a blood vessel and a method for operating the balloon catheter.

One embodiment of the balloon catheter of the present invention that has been able to solve the above problems is a shaft extending in the perspective direction, a first balloon provided on the distal side of the shaft, and the inside of the first balloon. The first balloon and the second balloon have a second balloon provided in the shaft, and a distal fixing portion fixed to the distal side of the shaft and a proximal side to the distal fixing portion, respectively. It has a proximal fixed portion fixed to the shaft and a non-fixed portion arranged between the distal fixed portion and the proximal fixed portion and not fixed to the shaft, and the second balloon is not fixed. In the first section from the distal end of the portion to a predetermined position on the distal side of the proximal end of the non-fixed portion of the second balloon, the first balloon and the second balloon are fixed to each other, and the first section The present invention is characterized in that at least a part of the inner surface surface of the first balloon is in contact with the outer surface surface of the second balloon. Proximal side of the first balloon of the first balloon while fixing the position of the catheter in the body by abutting the first section where the first balloon and the second balloon are fixed to the inner wall of the lumen. The body tissue can be suitably cauterized using this portion. More specifically, since the first balloon and the second balloon are fixed to each other and the balloon membranes are laminated in the first section, the rigidity can be increased. When the first section is inserted into the pulmonary vein through, for example, the opening of the pulmonary vein and the second balloon is expanded, the highly rigid first section contacts the inner wall of the pulmonary vein to fix the position of the catheter in the body. be able to. The pulmonary vein opening of the myocardium can then be cauterized by expanding the first balloon to bring the proximal side of the first section into contact with the pulmonary vein opening. Therefore, even if the operator pushes the catheter in order to bring the first balloon into close contact with the pulmonary vein opening during cauterization, it is possible to prevent over-insertion of the first balloon for cauterization into the pulmonary vein.

A heat insulating layer is further provided on the outer surface of the second balloon, and the heat insulating layer is arranged at least in the third section from the proximal end of the first section to the proximal end of the non-fixed portion of the second balloon, and is insulated. The layer is more than the specific heat capacity of a material having a thermal conductivity lower than the thermal conductivity of at least one of the materials of the first balloon and the second balloon, or the material of at least one of the first balloon and the second balloon. Also preferably contains a material having a large specific heat capacity.

The heat insulating layer extends to the first section, and the distal end of the heat insulating layer is preferably arranged between the first balloon and the second balloon.

In the third section from the proximal end of the first section to the proximal end of the non-fixed portion of the second balloon, a Peltier element is provided on the surface of the second balloon, and the Peltier element is on the heat dissipation surface and the side opposite to the heat dissipation surface. It is preferable that the heat absorbing surface is present on the second balloon side.

A heat insulating layer is further provided on the outer surface of the second balloon, and the heat insulating layer is arranged at least in the third section from the proximal end of the first section to the proximal end of the non-fixed portion of the second balloon to insulate. The layer is more than the specific heat capacity of a material having a thermal conductivity lower than the thermal conductivity of at least one of the materials of the first balloon and the second balloon, or the material of at least one of the first balloon and the second balloon. It is preferable that the Perche element is arranged on or in the heat insulating layer, which also contains a material having a large specific heat capacity.

The shaft has a third and fourth lumens communicating within the second balloon, and is further located proximal to or closer to the shaft, the third and fourth lumens. It is preferable to have a circulation part connected to the lumen.

It is preferable that the proximal ends of the fixed portions of the first balloon and the second balloon in the first section are arranged inward in the radial direction with respect to the common circumscribed line of the first balloon and the second balloon.

The proximal end of the non-fixed portion of the second balloon is preferably located distal to the proximal end of the non-fixed portion of the first balloon.

It is preferable that the first balloon and the second balloon are not fixed to each other in the second section proximal to the first section.

The second balloon is preferably made of a material having a higher durometer hardness than the first balloon.

The maximum outer diameter of the second balloon is preferably smaller than the maximum outer diameter of the first balloon.

It is preferable that a radiation opaque marker is provided at the position of the proximal end of the non-fixed portion of the second balloon on the shaft.

The temperature detection unit is provided on the shaft at a position proximal to the proximal end of the non-fixed portion of the second balloon and distal to the proximal end of the non-fixed portion of the first balloon. preferable.

It is preferable that the temperature detection unit is provided at the position of the non-fixed portion of the second balloon on the shaft.

One embodiment of the method of operating the balloon catheter includes a step of expanding the second balloon and a step of expanding the first balloon between the steps of expanding the second balloon or after completing the step of expanding the balloon catheter. It is characterized by that. According to this method, the position of the catheter in the body can be fixed by contacting the highly rigid first section with the inner wall of the pulmonary vein. As a result, even if the operator pushes the catheter in order to bring the first balloon into close contact with the pulmonary vein opening during ablation, it is possible to prevent over-insertion of the first balloon for ablation into the pulmonary vein.

According to the balloon catheter and its operating method, the position of the catheter in the body can be fixed, so that over-insertion of the first balloon for cauterization into the blood vessel can be prevented.

It shows the side view (partial sectional view) of the balloon catheter which concerns on one Embodiment of this invention. A side view (partial cross-sectional view) showing the structure inside the shaft of the balloon catheter shown in FIG. 1 is shown. A schematic diagram showing a usage mode of the balloon catheter shown in FIG. 1 is shown. A side view (partial cross-sectional view) showing a modified example of FIG. 2 is shown. A side view (partial cross-sectional view) showing a modified example of FIG. 1 is shown. A side view (partial cross-sectional view) showing another modified example of FIG. 1 is shown. A side view (partial cross-sectional view) showing still another modification of FIG. 1 is shown. A side view (partial cross-sectional view) showing a modified example of FIG. 7 is shown. A side view (partial cross-sectional view) showing still another modification of FIG. 1 is shown. A side view (partial cross-sectional view) showing another modified example of FIG. 7 is shown.

Hereinafter, the present invention will be described in more detail based on the following embodiments, but the present invention is not limited by the following embodiments as well as the present invention, and appropriate changes are made to the extent that it can be adapted to the purpose of the above and the following. In addition, it is of course possible to carry out, all of which are within the technical scope of the invention. In each drawing, hatching, member reference numerals, and the like may be omitted for convenience, but in such cases, the specification and other drawings shall be referred to. In addition, the dimensions of various members in the drawings may differ from the actual dimensions because priority is given to contributing to the understanding of the features of the present invention.

The balloon catheter will be described with reference to FIGS. 1 to 3. FIG. 1 shows a side view (partial cross-sectional view) of the balloon catheter according to the embodiment of the present invention, and FIG. 2 is a side view (partial cross-sectional view) showing the structure of the balloon catheter shown in FIG. 1 in the shaft. ), And FIG. 3 shows a schematic view showing a usage mode of the balloon catheter shown in FIG. In FIG. 2, the heater 33, the radiation opaque markers 40, 41, 42, and the temperature detection units 45, 46 are omitted in order to facilitate grasping the structure inside the shaft. The balloon catheter 1 has a shaft 10 and a first balloon 21 and a second balloon 22 provided on the distal side of the shaft. A gripping portion 48 for the operator to grip the catheter is preferably connected to the proximal side of the shaft 10.

An example of the use of the balloon catheter 1 is pulmonary vein isolation, which is one of the treatment methods for atrial fibrillation. In pulmonary vein isolation, a balloon catheter 1 is used to heat and cauterize the pulmonary vein opening by bringing a balloon containing heated fluid into contact with the pulmonary vein opening, resulting in abnormalities that cause atrial fibrillation. Can cut off various electrical paths. Hereinafter, the balloon catheter may be simply referred to as a catheter.

The proximal side of the balloon catheter 1 or the shaft 10 refers to the direction toward the hand side of the user (operator) with respect to the extending direction of the shaft 10, and the direction opposite to the distal side, that is, the treatment. Point to the direction of the target side. Further, the direction from the proximal side to the distal side of the shaft 10 or the direction from the distal side to the proximal side is referred to as a perspective direction.

The shaft 10 extends in the perspective direction. The shaft 10 usually has a flow path of a fluid supplied into the balloon (first lumens 11 to 6 chambers described later) and a wire insertion passage (not shown) for guiding the progress of the shaft 10. It is provided. In order to improve the flow of the fluid, it is preferable that the flow path of the fluid extends in the perspective direction of the shaft 10. The shaft 10 may have a coaxial structure composed of at least a double tube, or may have a multi-lumen structure having a plurality of lumens.

The shaft 10 preferably has flexibility. As a result, the shaft 10 can be deformed along the shape of the body cavity. Further, in order to maintain the shape, it is preferable that the shaft 10 has elasticity. The shaft 10 is preferably made of resin. Examples of the resin constituting the shaft 10 include polyamide-based resin, polyester-based resin, polyurethane-based resin, polyolefin-based resin, fluorine-based resin, vinyl chloride-based resin, silicone-based resin, natural rubber, and synthetic rubber. Only one of these may be used, or two or more thereof may be used in combination. As the resin constituting the shaft 10, either a thermoplastic resin or a thermosetting resin may be used, but it is particularly preferable to use a thermoplastic resin. The shaft 10 may have a laminated structure made of different materials or the same material, or a structure in which a plurality of tubes are joined together.

As shown in FIG. 1, a first balloon 21 is provided on the distal side of the shaft 10. Further, a second balloon 22 is provided in the first balloon 21. At least a part of the second balloon 22 may be covered with the first balloon 21, and the entire second balloon 22 may be covered with the first balloon 21. The balloon can be expanded by supplying a fluid inside the balloon. In addition, the balloon can be contracted by discharging the fluid from the inside of the balloon. It is preferable that the first balloon 21 and the second balloon 22 can be individually expanded and contracted in order to facilitate the positioning, heating, and cauterization of the catheter 1 in the body.

The balloon is preferably made of resin. Examples of the resin constituting the balloon include polyamide-based resin, polyester-based resin, polyurethane-based resin, polyolefin-based resin, vinyl chloride-based resin, silicone-based resin, and natural rubber. Only one of these may be used, or two or more thereof may be used in combination. Of these, polyamide-based resins, polyester-based resins, and polyurethane-based resins are preferably used. As these resins, elastomer resins can be used from the viewpoint of thinning the balloon and flexibility. The constituent materials of the first balloon 21 and the second balloon 22 may be the same or different from each other.

Hereinafter, the structure formed by a plurality of balloons including at least the first balloon 21 and the second balloon 22 may be referred to as a composite balloon 20. The composite balloon 20 has a position fixing portion 20a arranged in a blood vessel such as a pulmonary vein 50, and a cauterization portion 20b arranged proximal to the position fixing portion 20a and used for cauterizing the myocardium or the like. ing. Preferably, the second balloon 22 is anchored in the pulmonary vein 50 and the first balloon 21 cauterizes the myocardium.

The type of fluid supplied to the first balloon 21 and the second balloon 22 is not particularly limited, and for example, a liquid such as a physiological saline solution, a contrast medium, or a mixture thereof, or a gas such as air, nitrogen, or carbon dioxide gas. Can be used. The types of fluids supplied to the first balloon 21 and the second balloon 22 may be the same or different from each other. A liquid may be supplied to the inside of both the first balloon 21 and the second balloon 22.

The thermal conductivity of the fluid supplied to the inside of the second balloon 22 is preferably lower than the thermal conductivity of the fluid supplied to the inside of the first balloon 21. This makes it easier to keep the temperature of the position fixing portion 20a of the composite balloon 20 low, so that the influence on the pulmonary veins can be mitigated.

The fluid temperature inside the first balloon 21 can be, for example, 50 degrees or more, 52 degrees or more, or 55 degrees or more, or 70 degrees or less, 68 degrees or less, or 65 degrees or less. Will be done. As a result, the outer surface of the first balloon 21 can be brought to a temperature suitable for cauterization.

The fluid temperature inside the second balloon 22 is preferably lower than the fluid temperature inside the first balloon 21. As a result, the temperature of the position fixing portion 20a of the composite balloon 20 can be kept low, so that the influence on the pulmonary vein can be alleviated. The fluid temperature inside the second balloon 22 is preferably 5 degrees or more lower than the fluid temperature inside the first balloon 21, more preferably 10 degrees or more, still more preferably 20 degrees or more, and 40 degrees or less. It is preferably low, more preferably 35 degrees or less, or 30 degrees or less.

The first balloon 21 and the second balloon 22 have a distal fixing portion fixed to the distal side of the shaft 10 and a proximal fixing portion fixed to the shaft 10 proximal to the distal fixing portion, respectively. And a non-fixed portion that is arranged between the distal fixed portion and the proximal fixed portion and is not fixed to the shaft 10. In FIG. 1, the distal fixed portion of the first balloon 21 is indicated by reference numeral 21a, the proximal fixed portion is indicated by 21b, and the non-fixed portion is indicated by 21c. 22b and the non-fixed portion are indicated by 22c. By fixing each balloon to the shaft 10 in this way, the non-fixed portion can be expanded when a fluid is supplied to each balloon. It is preferable that the proximal fixing portion 21b of the first balloon 21 and the proximal fixing portion 22b of the second balloon 22 are also arranged on the distal side of the shaft 10. The lengths of the fixed portion and the non-fixed portion can be appropriately set as needed.

In order to make each balloon expandable individually, as shown in FIG. 2, the first and third lumens 11 and 13 extending in the perspective direction and the distal side of the shaft 10 The first side hole 16 which is formed on the peripheral wall of the shaft 10 and communicates with the first lumen 11 and the peripheral wall of the shaft 10 which is distal to the first side hole 16 are formed. A shaft 10 having a third side hole 18 communicating with the third lumen 13 can be used. Fluid feeders 31 and 32 such as syringes for supplying fluid to the inside of the first balloon 21 and the second balloon 22 are connected to the proximal side of the first lumen 11 and the third lumen 13. .. Each cavity of the shaft 10 and the fluid feeders 31 and 32 can be connected by using a connecting tube or a joint. The fluid feeders 31 and 32 may be provided with a heater or a cooler for heating and cooling the fluid, and the temperature of the fluid supplied from the fluid feeders 31 and 32 can be set and controlled as needed. .. After fixing both ends of the second balloon 22 in the perspective direction to the shaft 10 so that the third side hole 18 is arranged in the non-fixed portion 22c of the second balloon 22, the first side hole 16 is the first balloon 21. By fixing both ends of the first balloon 21 in the perspective direction to the shaft 10 directly or via the second balloon 22 so as to be arranged in the non-fixed portion 21c, the catheter 1 having the structure shown in FIGS. 1 and 2 can be obtained. Obtainable. Although not shown, a shaft having a lumen communicating with both the first balloon 21 and the second balloon 22 can also be used to expand the balloon. In this case, a first lumen extending in the perspective direction, a side hole formed on the peripheral wall of the shaft on the distal side of the shaft and communicating with the first lumen and the first balloon, A shaft can be used that is distal to the side hole and has a side hole formed in the peripheral wall of the shaft and communicating with the first lumen and the second balloon. A fluid feeder such as a syringe for supplying fluid to the inside of the first balloon and the second balloon is connected to the proximal side of the first lumen.

The shape of the non-fixed portion of the first balloon 21 and the second balloon 22 is not particularly limited, but may be a sphere, a spheroid, a pillar, a cone, or a combination thereof, respectively. The shapes of the first balloon 21 and the second balloon 22 may be the same or different from each other. In FIGS. 1 to 3, the non-fixed portion 21c of the first balloon 21 is formed in a pot-shaped or gourd-shaped shoulder with a neck, and the non-fixed portion 22c of the second balloon 22 is formed in a bale-shaped or barrel-shaped shape.

In the balloon catheter 1, in the first section 25 from the distal end of the non-fixed portion 22c of the second balloon 22 to a predetermined position distal to the proximal end of the non-fixed portion 22c of the second balloon 22. The 1st balloon 21 and the 2nd balloon 22 are fixed to each other. Since the first balloon 21 and the second balloon 22 are fixed to each other and the balloon membranes are laminated in the first section 25, the rigidity can be increased. The composite balloon 20 of the balloon catheter 1 corresponds to at least a part of the first section 25, and is arranged in a position fixing portion 20a arranged in the pulmonary vein 50 and a position proximal side to the position fixing portion 20a. It has a cauterizing portion 20b used for cauterizing. As shown in FIG. 3, when the first section 25 is inserted into the pulmonary vein 50 through, for example, the pulmonary vein opening 51 and the second balloon 22 is expanded, the highly rigid first section 25 becomes the inner wall 52 of the pulmonary vein 50. The position of the catheter 1 can be fixed by contacting with. Next, the pulmonary vein opening 51 can be heated and cauterized by expanding the first balloon 21 and bringing the proximal side of the first section 25 into contact with the pulmonary vein opening 51. Therefore, even if the operator pushes the catheter 1 in order to bring the first balloon 21 into close contact with the pulmonary vein opening 51 during ablation, the over-insertion of the first balloon 21 for ablation into the pulmonary vein 50 is prevented. be able to.

In the first section 25, the first balloon 21 and the second balloon 22 can be fixed by, for example, welding or adhesion with an adhesive.

In the first section 25, at least a part of the inner surface of the first balloon 21 is in contact with the outer surface of the second balloon 22. This makes it possible to prevent an increase in the balloon diameter (that is, the outer diameter of the composite balloon 20) in the first section 25. It is preferable that the inner surface of the first balloon 21 is in contact with the outer surface of the second balloon 22 in the portion including the distal end of the first section 25.

It is preferable that the first balloon 21 and the second balloon 22 are not fixed to each other in the second section 26 proximal to the first section 25. As a result, the first balloon 21 can be easily expanded in the second section 26, so that the second section 26 can be suitably used as the cauterization portion 20b. In this embodiment, the first balloon 21 and the second balloon 22 may come into contact with each other in the second section 26 during the procedure. The second section 26 is a section in which the position proximal to the first section 25 is the distal end and the proximal end of the non-fixed portion 21c of the first balloon 21 is the proximal end. As shown in FIGS. 1 and 2, the second section 26 is preferably adjacent to the first section 25. The proximal fixing portion 22b of the second balloon 22 may extend toward the proximal side in the non-fixing portion 21c of the first balloon and may be fixed to the proximal fixing portion 21b of the first balloon 21.

It is preferable that the sum of the film thicknesses of the first balloon 21 and the second balloon 22 in the first section 25 is larger than the film thickness of the first balloon 21 in the second section 26. As a result, the rigidity of the first section 25 can be increased, so that the effect of fixing the position of the catheter 1 in the pulmonary vein 50 can be further enhanced.

The lengths of the first section 25 and the second section 26 in the perspective direction may be the same or different from each other. In order to reduce the burden on the patient by shortening the length of the balloon inserted into the pulmonary vein 50 as much as possible, it is preferable that the first section 25 is shorter than the second section 26 in the perspective direction. Further, in order to bring the first section 25 into contact with the inner wall 52 of the pulmonary vein 50 over a wide area and enhance the effect of fixing the position of the catheter 1 in the pulmonary vein 50, the first section 25 is the second section 26 in the perspective direction. May be longer than.

The maximum outer diameter of the second balloon 22 is preferably smaller than the maximum outer diameter of the first balloon 21. This facilitates insertion of the first section 25 into the pulmonary vein 50. Further, since the proximal side of the first section 25 can be easily brought into contact with the pulmonary vein opening 51, cauterization can be easily performed.

It is preferable that the distal fixing portion 21a of the first balloon 21 is fixed to the distal fixing portion 22a of the second balloon 22 or is directly fixed to the shaft 10. The distal end of the distal fixation portion 21a of the first balloon 21 may be located at the same position as the distal end of the distal fixation portion 22a of the second balloon 22. Further, the distal end of the distal fixation portion 21a of the first balloon 21 may be arranged distal to the distal end of the distal fixation portion 22a of the second balloon 22, and is proximal to this. It may be arranged on the side. When the distal fixing portion 21a of the first balloon 21 is fixed to the distal fixing portion 22a of the second balloon 22, the distal fixing portion 21a of the first balloon 21 is the distal fixing portion of the second balloon 22. It may be fixed on the 22a, or the distal fixing portion 21a of the first balloon 21 and the distal fixing portion 22a of the second balloon 22 may be melted and integrated. Further, the distal fixing portion 21a of the first balloon 21 may have a portion fixed to the distal fixing portion 22a of the second balloon 22 and a portion directly fixed to the shaft 10.

Since the first balloon 21 and the second balloon 22 are fixed to each other in the first section 25, the proximal end of the distal fixing portion 21a of the first balloon 21 is close to the distal fixing portion 22a of the second balloon 22. It is located distal to the position. Due to the presence of the first section 25, the proximal end of the distal fixed portion 21a of the first balloon 21 is located distal to the distal end of the non-fixed portion 22c of the second balloon 22. There is. Since the first balloon 21 and the second balloon 22 are fixed to each other in the first section 25, the distal end of the non-fixed portion 21c of the first balloon 21 is the distal end of the non-fixed portion 22c of the second balloon 22. It is located distal to.

The proximal end of the non-fixed portion 22c of the second balloon 22 is preferably located distal to the proximal end of the non-fixed portion 21c of the first balloon 21. As a result, the first section 25 can be easily inserted into the pulmonary vein 50. Further, since the contact area between the fluids inside the two balloons via the membrane of the second balloon 22 can be reduced, the fluid temperature inside the first balloon 21 can be easily maintained and cauterization can be easily performed.

The proximal end of the non-fixed portion 22c of the second balloon 22 is preferably located distal to the central position of the non-fixed portion 21c of the first balloon 21 in the perspective direction. As a result, the first section 25 can be easily formed short, so that excessive contact of the balloon with the inner wall 52 of the pulmonary vein 50 can be suppressed. Further, the proximal end of the non-fixed portion 22c of the second balloon 22 may be arranged proximally to the central position in the perspective direction of the non-fixed portion 21c of the first balloon 21. As a result, the first section 25 can be easily formed to be long, so that the effect of fixing the position of the catheter 1 in the pulmonary vein 50 can be further enhanced.

Although not shown, the proximal end of the non-fixed portion 22c of the second balloon 22 may be located proximal to the proximal end of the non-fixed portion 21c of the first balloon 21. As a result, the second balloon 22 can be arranged over a wide range inside the first balloon 21, so that the amount of fluid supplied to the inside of the first balloon 21 can be reduced.

The distal end of the proximal fixation 21b of the first balloon 21 may be located at the same position as the distal end of the proximal fixation 22b of the second balloon 22. Further, the distal end of the proximal fixing portion 21b of the first balloon 21 may be arranged proximally to the distal end of the proximal fixing portion 22b of the second balloon 22, and is arranged on the distal side. It may have been. Further, the proximal end of the proximal fixation portion 21b of the first balloon 21 may be located proximal to the distal end of the proximal fixation portion 22b of the second balloon 22, and may be located distally. It may be arranged at the same position.

The proximal end of the first section 25 may be located proximal to the near-perspective center position of the first balloon 21. As a result, the first section 25 easily contacts the inner wall 52 of the pulmonary vein 50 in a wide range, so that the effect of fixing the position of the catheter 1 in the pulmonary vein 50 can be enhanced.

The proximal end of the first section 25 may be located distal to the near-perspective center position of the first balloon 21. As a result, the first section 25 can be easily formed short, so that excessive contact of the balloon with the inner wall 52 of the pulmonary vein 50 can be suppressed.

Each balloon may have elasticity to allow the balloon to expand and contract.
The second balloon 22 is preferably made of a material having a higher durometer hardness than the first balloon 21. The durometer hardness of the constituent material of the second balloon 22 is more preferably 1.2 times or more, more preferably 1.5 times or more, and 5 times larger than the durometer hardness of the constituent material of the first balloon 21. It is permissible to be less than twice, less than four times, or less than three times larger. As a result, the rigidity of the first section 25 can be further increased, so that the first section 25 can easily bite into the inner wall 52 of the pulmonary vein 50, and the position of the first section 25 can be easily fixed. Further, since the proximal side of the first section 25 is flexibly formed, the first balloon 21 can be easily brought into close contact with the pulmonary vein opening 51.

The film thickness of the first balloon 21 and the second balloon 22 before expansion can be, for example, 30 μm or more, 40 μm or more, or 50 μm or more, and can be 150 μm or less, 120 μm or less, or 100 μm or less, respectively. To. The film thicknesses of the first balloon 21 and the second balloon 22 before expansion may be the same or different from each other.

A heater 33 is provided on the shaft 10 at a position proximal to the proximal end of the non-fixed portion 22c of the second balloon 22 and distal to the proximal end of the non-fixed portion 21c of the first balloon 21. It is preferable that it is. As a result, the fluid supplied into the first balloon 21 can be heated, and the body tissue can be heated and cauterized using the first balloon 21.

Examples of the heater 33 include heating electrodes provided on the shaft 10. The heating electrode is electrically connected to the high frequency generator via a conducting wire extending in the shaft 10. High-frequency power is supplied to the heating electrode by the high-frequency generator, and high-frequency energization is performed between the heating electrode and the extracorporeal electrode provided outside the patient's body to heat the fluid supplied inside the balloon. , Can be cauterized. As shown in FIG. 1, the heating electrode as the heater 33 can be formed in the shape of a coil wound around the outer circumference of the shaft 10, for example. The extracorporeal electrode can be formed in a plate shape, for example. The heating electrode and the extracorporeal electrode can be made of a conductive material such as gold, silver, copper, platinum, or aluminum.

The heater 33 is arranged on the shaft 10 at a position proximal to the proximal end of the non-fixed portion 22c of the second balloon 22 and distal to the proximal end of the non-fixed portion 21c of the first balloon 21. It is preferable that the heater 33 is not arranged on the non-fixed portion 22c of the second balloon 22 on the shaft 10. By not arranging the heater 33 in the non-fixed portion 22c of the second balloon 22 in this way, the temperature rise of the fluid supplied into the second balloon 22 can be suppressed, so that the pulmonary vein 50 by the second balloon 22 can be suppressed. The impact on can be mitigated.

A modified example of the balloon catheter 1 will be described with reference to FIGS. 4 to 10. 4 shows a modified example of FIG. 2, FIGS. 5 to 7 and 9 show a modified example of FIG. 1, and FIGS. 8 and 10 show a modified example of FIG. 7. The shaft 10 has a first lumen 11 communicating with the first balloon 21, and is further located proximal to the shaft 10 or proximal to the shaft 10 and connects to the first lumen 11. It is preferable to have a heating unit 34 which is formed. By providing the heating unit 34 outside the balloon in this way, the fluid inside the first balloon 21 can be heated.

The heating unit 34 has a heating device that heats the fluid. In the heating device, the fluid can be heated to a temperature suitable for cauterization by a method of resistance heating, infrared heating, microwave heating, and dielectric heating. The heating unit 34 is connected to a fluid supply unit 31 that supplies a fluid into the first balloon 21, and the fluid supply unit 31 supplies the heated fluid through the first cavity 11 into the inside of the first balloon 21. However, it may have a pump for discharging the fluid from the inside of the first balloon 21.

As shown in FIG. 4, the shaft 10 has a first lumen 11 and a second lumen 12 communicating with the first balloon 21, and is further proximal to the shaft 10 or closer than the shaft 10. It is preferable to have a heating portion 34 which is arranged on the position side and is connected to the first lumen 11 and the second lumen 12. By connecting the heating unit 34 and the first balloon 21 through the plurality of lumens in this way, the fluid supplied into the first balloon 21 can be circulated, and heating can be performed efficiently. In FIG. 4, a second side hole 17 communicating with the second lumen 12 is formed in the peripheral wall on the distal side of the shaft 10. The second side hole 17 is located at the position of the non-fixed portion 21c of the first balloon 21 and is arranged proximal to the proximal end of the proximal fixed portion 22b of the second balloon 22. For example, the first cavity 11 can be used as a fluid supply path to the first balloon 21, and the second lumen 12 can be used as a fluid discharge path from the first balloon 21. In the first balloon 21, the first side hole 16 communicating with the first cavity 11 and the second side hole 17 communicating with the second cavity 12 are farther from the second side hole 17 than the second side hole 17. It may be arranged on the position side, may be arranged on the proximal side, or may be located at the same position in the perspective direction.

The shaft 10 has a third lumen 13 communicating with the second balloon 22, and is further located proximal to the shaft 10 or proximal to the shaft 10 and connects to the third lumen 13. It is preferable to have a circulating portion 35 that is formed. As a result, the fluid in the second balloon 22 can be cooled, so that the temperature rise of the position fixing portion 20a of the composite balloon 20 can be suppressed.

The circulation unit 35 has a cooling device for cooling the fluid. In the cooling device, a temperature equivalent to the body temperature (for example, 35 to 42 degrees) is used by methods such as gas cooling using air or carbon dioxide, phase change cooling using a heat pipe, or liquid cooling using insulating oil. ) Can be cooled. The circulation unit 35 is connected to the fluid supply unit 32 that supplies the fluid into the second balloon 22, and supplies the fluid cooled through the third lumen 13 to the inside of the second balloon 22 to supply the second balloon 22. It may have a pump that discharges the fluid from the inside of the.

The shaft 10 has a third lumen 13 and a fourth lumen 14 communicating with each other in the second balloon 22, and is further located on the proximal side of the shaft 10 or on the proximal side of the shaft 10 and has a second position. It is preferable to have a circulation portion 35 connected to the 3 lumen 13 and the 4th lumen 14. By connecting the circulation portion 35 and the second balloon 22 through the plurality of lumens in this way, the fluid supplied into the second balloon 22 can be circulated, and cooling can be efficiently performed. In FIG. 4, a fourth side hole 19 communicating with the fourth lumen 14 is formed in the peripheral wall on the distal side of the shaft 10. The fourth side hole 19 is arranged at the position of the non-fixed portion 22c of the second balloon 22. For example, the third lumen 13 can be used as a fluid supply path to the second balloon 22, and the fourth lumen 14 can be used as a fluid discharge path from the second balloon 22. In the second balloon 22, the third side hole 18 communicating with the third lumen 13 and the fourth side hole 19 communicating with the fourth lumen 14 are farther from the fourth side hole 19 than the fourth side hole 19. It may be arranged on the position side, may be arranged on the proximal side, or may be located at the same position in the perspective direction.

As shown in FIG. 1, the shaft 10 is provided with one or more radiation opaque markers 40, 41, 42 (hereinafter, may be simply referred to as markers) in order to confirm the position of the balloon in the perspective direction. It is preferable to have. The shape of the marker is preferably a cylinder, and examples thereof include a cylinder, a polygonal cylinder, a C-shaped cross section with a notch in the cylinder, and a coil shape in which a wire rod is wound.

The marker is preferably composed of, for example, an X-ray opaque material such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, and cobalt-chromium alloy.

It is preferable that the marker 40 is provided at the position of the proximal end of the non-fixed portion 22c of the second balloon 22 on the shaft 10. This makes it possible to confirm the insertion state of the cauterized portion 20b into the pulmonary vein 50. The marker 40 may be arranged so as to overlap the proximal fixed portion 22b and the non-fixed portion 22c of the second balloon 22.

It is preferable that the marker 41 is provided at the position of the distal end portion of the non-fixed portion 22c of the second balloon 22 on the shaft 10. Thereby, the insertion state of the distal end portion of the first section 25 into the pulmonary vein 50 can be confirmed. The marker 41 may be arranged so as to overlap the distal fixed portion 22a and the non-fixed portion 22c of the second balloon 22.

Although not shown, it is preferable that a marker is provided at the position of the proximal end of the first section 25 on the shaft 10. It is more preferred that the markers be aligned with the proximal end of the first section 25 on the shaft 10 when the first balloon 21 and the second balloon 22 are expanded. This makes it possible to confirm the insertion state of the proximal end of the first section 25 into the pulmonary vein 50.

It is preferable that the marker 42 is provided at the position of the proximal end of the non-fixed portion 21c of the first balloon 21 on the shaft 10. This makes it possible to confirm the insertion state of the cauterized portion 20b into the pulmonary vein 50. The marker 42 may be arranged so as to overlap the proximal fixed portion 21b and the non-fixed portion 21c of the first balloon 21.

It is preferable that the shaft 10 is provided with a temperature detection unit in order to detect the fluid temperature inside the balloon or estimate the temperature of the tissue to be cauterized. As the temperature detection unit, a temperature sensor such as a thermocouple or a temperature measuring element can be used. The temperature detection unit may be attached to the outer peripheral surface of the shaft 10, may be embedded in the peripheral wall of the shaft 10, or may be embedded in a heater (heating electrode). One or a plurality of temperature detection units may be provided.

As shown in FIG. 1, it is proximal to the proximal end of the non-fixed portion 22c of the second balloon 22 on the shaft 10 and distal to the proximal end of the non-fixed portion 21c of the first balloon 21. It is preferable that the temperature detection unit 46 is provided at the position. As a result, it is possible to detect the fluid temperature inside the first balloon 21 and estimate the temperature of the outer surface of the first balloon 21 proximal to the first section 25. The temperature detection unit 46 provided on the side of the first balloon 21 can control the temperature during cauterization. For example, when the temperature detected by the temperature detection unit 46 reaches a predetermined value by the control unit connected to the temperature detection unit 46 and the heater 33 or the heating unit 34, the heating by the heater 33 or the heating unit 34 is performed. Control to stop can be performed.

As shown in FIG. 1, it is preferable that the temperature detection unit 45 is provided at the position of the non-fixed portion 22c of the second balloon 22 on the shaft 10. As a result, it is possible to detect the temperature inside the second balloon 22 and estimate the temperature of the outer surface of the first balloon 21 in the first section 25. For example, when the temperature detected by the temperature detection unit 45 provided on the second balloon 22 side reaches a predetermined value, a warning regarding the heating of the first balloon can be issued.

Although not shown, the catheter 1 may be provided with a vibration generating portion for applying vibration to the fluid inside the first balloon 21. The vibration generating portion is connected so as to communicate with the inside of the first balloon 21. Since the fluid inside the first balloon 21 can be agitated by vibration by the vibration generating portion, the temperature of the fluid inside the first balloon 21 for cauterization can be made uniform. As the vibration generating unit, for example, an ultrasonic vibration device can be used.

As shown in FIG. 2, the proximal ends of the fixed portions of the first balloon 21 and the second balloon 22 in the first section 25 are within the radial direction of the common circumscribed line L of the first balloon 21 and the second balloon 22. It is preferable that they are arranged in one direction. As a result, a shoulder portion 28 having a rapidly increasing outer diameter of the composite balloon 20 can be formed at the proximal end of the first section 25. Since the shoulder 28 abuts against the pulmonary vein opening 51 when the distal side of the proximal end of the first section 25 is inserted into the pulmonary vein 50, the first balloon 21 for cauterizing into the pulmonary vein 50 Over-insertion can be prevented. The common circumscribed line L is a line tangent to the portion of the second balloon 22 in the first section 25 and the portion of the first balloon 21 located proximal to the first section 25.

In FIG. 5, as a modified example, the catheter 1 in which the non-fixed portion 21c of the first balloon 21 and the non-fixed portion 22c of the second balloon 22 are formed in a long spherical shape is shown. As shown in FIG. 5, the proximal ends of the fixed portions of the first balloon 21 and the second balloon 22 in the first section 25 are arranged on the common circumscribed line L of the first balloon 21 and the second balloon 22. May be good. As a result, the first section 25 can be formed short, so that excessive contact of the balloon with the inner wall 52 of the pulmonary vein 50 can be suppressed. Further, since the cautery portion 20b can be deformed according to the insertion depth into the pulmonary vein 50, a catheter 1 applicable to various patients can be obtained.

Although not shown, the outer periphery of the second balloon 22 may be provided with a protruding portion protruding outward in the radial direction. As a result, the first section 25 can easily bite into the inner wall 52 of the pulmonary vein 50, and the first section 25 can be easily fixed. In order to firmly fix the first section 25 in the body, it is preferable that the second balloon 22 is provided with a plurality of protrusions. In that case, it is preferable that a plurality of protruding portions are arranged side by side in the circumferential direction of the second balloon 22. The protrusions are preferably solid and preferably linear. The protruding portion may extend in the perspective direction or the circumferential direction, or may extend in a spiral shape centered on the perspective direction of the shaft 10. In order to make it easier for the first section 25 to bite into the inner wall 52 of the pulmonary vein 50, the protrusion is formed to be narrower in the radial direction in the cross section perpendicular to the perspective direction of the second balloon 22. Is preferable.

As shown in FIG. 6, a third balloon 23 is further provided in the first balloon 21, and the third balloon 23 has a distal fixing portion 23a fixed to the shaft 10 and a distal fixing portion 23a. The proximal fixed portion 23b fixed to the shaft 10 on the proximal side of the shaft 10 and the non-fixed portion 23c arranged between the distal fixed portion 23a and the proximal fixed portion 23b and not fixed to the shaft 10. The distal end of the non-fixed portion 23c of the third balloon 23 is preferably located proximal to the proximal end of the non-fixed portion 22c of the second balloon 22. By providing the third balloon 23, the amount of fluid supplied to the inside of the first balloon 21 used for cauterization can be reduced.

Although not shown, the shaft 10 preferably has a fifth lumen communicating with the third balloon 23. In that case, it is preferable that the shaft 10 has a fifth side hole formed in the peripheral wall and communicating with the fifth lumen. In that case, before fixing the first balloon 21 to the shaft 10, both ends of the third balloon 23 in the perspective direction are fixed to the shaft 10 so that the fifth side hole is arranged in the non-fixed portion of the third balloon. It is preferable to do so. In addition to the fifth lumen, the shaft 10 may be provided with a sixth lumen communicating with the third balloon 23. By using the plurality of lumens as a flow path in this way, the fluid supplied into the third balloon 23 can be circulated, and heating or cooling can be efficiently performed. A fluid feeder, a heating unit, or a circulation unit for supplying a fluid to the inside of the third balloon 23 is provided on the proximal side of at least one of the fifth and sixth lumens.

The distal end of the distal fixation portion 23a of the third balloon 23 may be located proximal to the proximal end of the proximal fixation portion 22b of the second balloon 22 and may be located distally. You may. By setting the position of the distal fixing portion 23a of the third balloon 23 in this way, the length of the composite balloon 20 in the perspective direction can be adjusted.

For the arrangement of the proximal fixing portion 23b of the third balloon 23, the description of the arrangement of the proximal fixing portion 22b of the second balloon 22 can be referred to. Further, regarding the third balloon 23, the description of the first balloon 21 and the second balloon 22 can be referred to for the fluid, balloon shape and film thickness supplied to the inside of the balloon.

As shown in FIG. 6, it is preferable that the marker 43 is provided at the position of the distal end portion of the third balloon 23 on the shaft 10. This makes it possible to confirm the insertion state of the cauterized portion 20b into the pulmonary vein 50. Further, it is preferable that the marker 44 is provided at the position of the proximal end of the third balloon 23 on the shaft 10. As a result, the position of the third balloon 23 in the body can be confirmed.

As shown in FIG. 6, it is preferable that the temperature detection unit 47 is provided at the position of the non-fixed portion 23c of the third balloon 23 on the shaft 10. As a result, the temperature inside the third balloon 23 can be detected.

In FIG. 7, as a modification, a catheter 1 further provided with a heat insulating layer 29 on the outer surface of the second balloon 22 is shown. As shown in FIG. 7, a heat insulating layer 29 is further provided on the outer surface of the second balloon 22, and the heat insulating layer 29 is provided from the proximal end of the first section 25 to the proximal end of the non-fixed portion 22c of the second balloon 22. At least arranged in the third section 27 up to, the heat insulating layer 29 is a material having a thermal conductivity lower than the thermal conductivity of at least one of the materials of the first balloon 21 and the second balloon 22, or the first It is preferable to include a material having a specific heat capacity larger than the specific heat capacity of at least one of the materials of the 1 balloon 21 and the 2nd balloon 22. Even if a high-temperature fluid for cauterization is supplied into the first balloon 21, heat is reflected or absorbed by the heat insulating layer 29, so that the temperature of the fluid in the second balloon 22 can be prevented from rising, and cauterization can be performed. It is possible to prevent cauterization of a site other than the desired site, for example, the inner wall of the pulmonary vein.

Examples of the heat insulating layer 29 include a heat insulating sheet and a heat insulating film. As the material of the heat insulating layer 29, a resin similar to the resin used for the balloon can be used. The material constituting the second balloon 22 and the resin constituting the heat insulating layer 29 may be the same or different.

For example, the heat insulating layer 29 may include a base material and bubbles or fillers existing in the base material and having a larger specific heat capacity or a lower thermal conductivity than the base material. As a result, even if a high-temperature fluid for cauterization is supplied into the first balloon, heat is reflected or absorbed by air bubbles or fillers in the heat insulating layer, so that the heat from the first balloon is distal to the second balloon. It becomes difficult to convey to the side. Therefore, it is possible to prevent cauterization of a site other than the desired site, for example, the inner wall of the pulmonary vein.

In order to enhance the heat insulating effect, the bubbles or fillers are preferably dispersed in the base metal. Above all, it is preferable that the heat insulating layer 29 has a sea-island structure, and the base material is a sea portion and the air bubbles or filler is an island portion. When the heat insulating layer 29 has such a structure, the heat insulating effect between the first balloon 21 and the second balloon 22 is further enhanced.

A resin can be used as the material constituting the base material, and specifically, a polyamide resin, a polyester resin, a polyurethane resin, a polyolefin resin, a polyimide resin, a fluorine resin, a vinyl chloride resin, and a silicone resin. Examples thereof include resin, natural rubber, and synthetic rubber.

In order to further enhance the heat insulating effect, the base material has a thermal conductivity lower than the thermal conductivity of at least one of the first balloon 21 and the second balloon 22, or the first balloon 21 and the first 2 It is preferable to include a material having a specific heat capacity larger than the specific heat capacity of at least one of the materials of the balloon 22.

When bubbles are present in the heat insulating layer 29, the heat insulating layer 29 preferably has a closed cell structure because it has excellent heat insulating properties. The type of gas contained in the bubbles is not particularly limited, and for example, air or nitrogen can be used.

The shape of the filler is not particularly limited, but may be spherical or other particle-like, needle-like, fibrous, or plate-like. The filler may have a solid shape or a hollow shape, but is preferably a hollow shape in order to obtain a lightweight and high heat insulating effect. The material constituting the filler is not particularly limited, and may be an organic material, an inorganic material, or an organic-inorganic composite material. Examples of the organic material include thermosetting resins such as phenol, epoxy and urea, and thermoplastic resins such as polyester, polyvinylidene chloride, polystyrene and polymethacrylate. Examples of the inorganic material include shirasu, pearlite, glass, silica, alumina, zirconia, carbon and the like. Above all, from the viewpoint of biocompatibility, light weight, and toughness against expansion of the second balloon 22, the filler is preferably resin particles.

The heat insulating layer 29 is preferably arranged so as to cover the entire circumferential direction of the second balloon 22. As a result, the heat insulating effect is enhanced, and the temperature rise of the fluid in the second balloon 22 can be further prevented.

FIG. 8 shows a cross-sectional view showing a modification of FIG. 7. As shown in FIG. 8, the heat insulating layer 29 extends to the first section 25, and the distal end portion of the heat insulating layer 29 is arranged between the first balloon 21 and the second balloon 22. Is preferable. As a result, the heat from the first balloon 21 is less likely to be transmitted to the distal side of the second balloon 22, so that it is possible to prevent cauterization of a site other than the desired site, for example, the inner wall of the pulmonary vein. ..

The distal end of the heat insulating layer 29 may be located distal to the near-perspective center position of the non-fixed portion 22c of the second balloon 22, or may be located proximally. 2 In order to prevent heat transfer to the distal side of the balloon 22, it is preferable that the balloon 22 is arranged on the distal side.

The proximal end of the heat insulating layer 29 is preferably located proximal to the proximal end of the non-fixed portion 22c of the second balloon 22. As a result, the heat insulating layer 29 can be provided over a wide range in the perspective direction, so that the heat insulating effect can be enhanced.

The thickness of the heat insulating layer 29 is preferably the same as or thinner than the film thickness of the second balloon 22. By setting the thickness of the heat insulating layer 29 in this way, it is possible to prevent the outer diameter of the position fixing portion 20a from becoming excessively large.

In FIG. 9, as a modification, a catheter 1 further provided with a Peltier element 30 on the surface of the second balloon 22 is shown. As shown in FIG. 9, a Peltier element 30 is provided on the surface of the second balloon 22 in the third section 27 from the proximal end of the first section 25 to the proximal end of the non-fixed portion 22c of the second balloon 22. The Peltier element 30 preferably has a heat radiating surface and a heat absorbing surface opposite to the heat radiating surface, and the heat absorbing surface is present on the second balloon 22 side. As a result, the heat of the second balloon 22 can be dissipated to the first balloon 21 side, so that the temperature rise of the fluid in the second balloon 22 can be prevented.

The Peltier element 30 is preferably arranged in at least a part of the third section 27, and more preferably arranged in the entire third section 27.

One or more Peltier elements 30 may be provided. In order to efficiently cool the fluid in the second balloon 22, the catheter 1 preferably includes a plurality of Peltier elements 30, and the plurality of Peltier elements 30 are arranged side by side in the circumferential direction of the shaft 10. Is more preferable. Further, the Peltier elements 30 may be arranged side by side along the perspective direction.

The Peltier element 30 may be arranged on the outer surface of the second balloon 22 or may be arranged on the inner surface of the second balloon 22. Further, the Peltier element 30 may be arranged on the outer side surface and the inner side surface of the second balloon 22, respectively.

The heat insulating layer 29 and the Peltier element 30 can be fixed to the surface of the second balloon 22 by welding or adhesion with an adhesive or the like.

In FIG. 10, as a further modification, the catheter 1 further provided with both the heat insulating layer 29 and the Peltier element 30 on the second balloon 22 is shown. As shown in FIG. 10, a heat insulating layer 29 is further provided on the outer surface of the second balloon 22, and the heat insulating layer 29 is provided from the proximal end of the first section 25 to the proximal end of the non-fixed portion 22c of the second balloon 22. At least arranged in the third section 27 up to, the heat insulating layer 29 is a material having a thermal conductivity lower than the thermal conductivity of at least one of the materials of the first balloon 21 and the second balloon 22, or the first The Perche element 30 may be arranged on or in the heat insulating layer 29, including a material having a specific heat capacity larger than the specific heat capacity of at least one of the materials of the 1 balloon 21 and the 2nd balloon 22. preferable. As a result, the fluid in the second balloon 22 can be cooled more efficiently due to the synergistic effect of the heat insulation by the heat insulating layer 29 and the cooling by the Peltier element 30.

The method of operating the balloon catheter 1 includes a step of expanding the second balloon 22 and a step of expanding the first balloon 21 between the steps of expanding the second balloon 22 or after completing the step of expanding the balloon catheter 1. doing. By expanding the second balloon 22, the position of the catheter 1 can be fixed by the highly rigid first section 25 coming into contact with the inner wall 52 of the pulmonary vein 50. By expanding the first balloon 21 during the step of expanding the second balloon 22 or after completing the step of expanding the second balloon 22, the proximal side of the first section 25 is brought into contact with the pulmonary vein opening 51. And the pulmonary vein opening 51 can be cauterized. Therefore, even if the operator pushes the catheter 1 in order to bring the first balloon 21 into close contact with the pulmonary vein opening 51 during ablation, the over-insertion of the first balloon 21 for ablation into the pulmonary vein 50 is prevented. be able to. The timing for starting the expansion of the first balloon 21 may be after the expansion of the second balloon 22 is completed, or may be during the expansion of the second balloon 22. In particular, it is preferable to start dilation of the first balloon 21 after the first section 25 comes into contact with the inner wall 52 of the pulmonary vein 50. For example, after the second balloon 22 is dilated and fixed in the pulmonary vein 50, the first balloon 21 can be dilated to cauterize the myocardium. Further, a method in which the second balloon 22 and the first balloon 21 are slightly expanded, and the position of both is confirmed under fluoroscopy, the second balloon 22 is fully expanded and fixed, and then the first balloon 21 is expanded. and so on. The balloon to be expanded first may be the first balloon 21 or the second balloon 22.

The expansion pressure of the first balloon 21 depends on the physical properties of the balloon membrane, but when the physical properties of the balloon membrane are the same for the first balloon 21 and the second balloon 22, it is smaller than the expansion pressure of the second balloon 22. Is preferable. As a result, the rigidity of the first section 25 is increased, which makes it easier to fix the position of the catheter 1 in the pulmonary vein 50, and the proximal side of the first section 25 is flexibly formed, so that the first balloon is formed. 21 can be easily brought into close contact with the pulmonary vein opening 51.

When the catheter 1 has the third balloon 23, it is preferable to have a step of expanding the third balloon 23 after the expansion of the second balloon 22 and before the expansion of the first balloon 21. As a result, the amount of fluid supplied to the inside of the first balloon 21 used for cauterization can be reduced.

1: Balloon catheter 10: Shaft 11: First lumen 12: Second lumen 13: Third lumen 14: Fourth lumen 16: First side hole 17: Second side hole 18: Third side hole 19 : 4th side hole 20: Composite balloon 20a: Position fixing part 20b: Caulking part 21: First balloon 21a: Distal fixing part 21b: Proximal fixing part 21c: Non-fixing part 22: Second balloon 22a: Distal fixing Part 22b: Proximal fixed part 22c: Non-fixed part 23: Third balloon 23a: Distal fixed part 23b: Proximal fixed part 23c: Non-fixed part 25: First section 26: Second section 27: Third section 28 : Shoulder 29: Insulation layer 30: Perche element 31, 32: Fluid feeder 33: Heater 34: Heating part 35: Circulation part 40, 41, 42, 43, 44: Radiation opaque markers 45, 46, 47: Temperature detection unit 48: Grip unit 50: Pulmonary vein 51: Pulmonary vein opening 52: Pulmonary vein inner wall L: Common extrinsic line

Claims (15)

The shaft extending in the perspective direction and
A first balloon provided on the distal side of the shaft and
It has a second balloon provided in the first balloon, and has.
The first balloon and the second balloon are a distal fixing portion fixed to the distal side of the shaft and a proximal fixing portion fixed to the shaft proximal to the distal fixing portion, respectively. It has a portion and a non-fixed portion that is disposed between the distal fixed portion and the proximal fixed portion and is not fixed to the shaft.
In the first section from the distal end of the non-fixed portion of the second balloon to a predetermined position on the distal side of the proximal end of the non-fixed portion of the second balloon, the first balloon and the first balloon. 2 balloons are fixed to each other
A balloon catheter in which at least a part of the inner surface of the first balloon is in contact with the outer surface of the second balloon in the first section. An insulating layer is further provided on the outer surface of the second balloon.
The heat insulating layer is arranged at least in a third section from the proximal end of the first section to the proximal end of the non-fixed portion of the second balloon.
The heat insulating layer is a material having a thermal conductivity lower than the thermal conductivity of at least one of the first balloon and the second balloon, or at least one of the first balloon and the second balloon. The balloon catheter according to claim 1, further comprising a material having a specific heat capacity larger than the specific heat capacity of the material. The heat insulating layer extends to the first section and extends to the first section.
The balloon catheter according to claim 2, wherein the distal end of the heat insulating layer is arranged between the first balloon and the second balloon. In the third section from the proximal end of the first section to the proximal end of the non-fixed portion of the second balloon.
A Peltier element is provided on the surface of the second balloon.
The balloon according to any one of claims 1 to 3, wherein the Peltier element has a heat radiating surface and an endothermic surface opposite to the heat radiating surface, and the endothermic surface exists on the second balloon side. catheter. An insulating layer is further provided on the outer surface of the second balloon.
The heat insulating layer is arranged at least in a third section from the proximal end of the first section to the proximal end of the non-fixed portion of the second balloon.
The heat insulating layer is a material having a thermal conductivity lower than the thermal conductivity of at least one of the first balloon and the second balloon, or at least one of the first balloon and the second balloon. Contains materials that have a specific heat capacity greater than the specific heat capacity of the material in
The balloon catheter according to claim 4, wherein the Peltier element is arranged on the heat insulating layer or in the heat insulating layer. The shaft has a third and fourth lumens communicating within the second balloon.
Further, any of claims 1 to 5, further comprising a circulation portion located proximal to the shaft or proximal to the shaft and connected to the third lumen and the fourth lumen. The balloon catheter according to paragraph 1. Claim that the proximal end of the fixed portion of the first balloon and the second balloon in the first section is arranged inward in the radial direction from the common tangent line of the first balloon and the second balloon. The balloon catheter according to any one of 1 to 6. The balloon according to any one of claims 1 to 7, wherein the proximal end of the non-fixed portion of the second balloon is arranged distal to the proximal end of the non-fixed portion of the first balloon. catheter. The balloon catheter according to any one of claims 1 to 8, wherein the first balloon and the second balloon are not fixed to each other in the second section proximal to the first section. The balloon catheter according to any one of claims 1 to 9, wherein the second balloon is made of a material having a durometer hardness higher than that of the first balloon. The balloon catheter according to any one of claims 1 to 10, wherein the maximum outer diameter of the second balloon is smaller than the maximum outer diameter of the first balloon. The balloon catheter according to any one of claims 1 to 11, wherein a radiation opaque marker is provided at a position of a proximal end portion of a non-fixed portion of the second balloon on the shaft. A temperature detection unit is provided on the shaft at a position proximal to the proximal end of the non-fixed portion of the second balloon and distal to the proximal end of the non-fixed portion of the first balloon. The balloon catheter according to any one of claims 1 to 12. The balloon catheter according to any one of claims 1 to 13, wherein a temperature detection unit is provided at a position of a non-fixed portion of the second balloon on the shaft. The method for operating the balloon catheter according to any one of claims 1 to 14.
A method having a step of expanding the first balloon between the step of expanding the second balloon and the step of expanding the second balloon, or after completing the step of expanding the balloon.

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