Balloon catheter

Abstract

A balloon catheter comprises: a shaft 12 that is to be inserted into a body; a balloon 14 that is provided to the leading end-side part of the shaft 12; a heating member that can heat a liquid to be supplied into the balloon 14; and a heating member conducting wire 20 which is electrically connected to the heating member. Inside the shaft 12, a first lumen 60 into which the heating member conducting wire 20 is inserted and a second lumen 62 that is different from the first lumen 60 are formed. One of the first lumen 60 and the second lumen 62 forms a supply flow path 64 through which the liquid supplied to the balloon 14 flows, and the other of the first lumen 60 and the second lumen 62 forms a discharge flow path 66 through which the fluid discharged from the inside of the balloon 14 flows.

Description

Balloon catheter

[0001] The present disclosure relates to balloon catheters.

[0002] Patent Document 1 discloses a balloon catheter including a shaft, a balloon provided at the distal end of the shaft, a heating element capable of heating a liquid supplied into the balloon, and a heating element lead wire electrically connected to the heating element. The heating element lead wire is inserted into a first lumen formed inside the shaft and is electrically connected to an external power supply device.

[0003] Japanese Patent Application Laid-Open No. 2004-305251

[0004] In some cases, the distal end of the first lumen is sealed by welding or the like to prevent liquid from flowing into the first lumen inside the shaft, and a second lumen is formed inside the shaft separately from the first lumen. In this case, the second lumen functions as both a supply flow path through which liquid flows to be supplied into the balloon and a discharge flow path through which liquid flows out of the balloon.

[0005] The inventors of the present application have newly recognized that sealing the distal end of the first lumen in this manner poses the following problem. Specifically, in this case, even if the gas inside the balloon has been sufficiently evacuated in advance, a small amount of gas inside the first lumen that is proximal to the sealed portion of the first lumen will leak into the balloon. If gas leaks into the balloon, the gas will remain inside the balloon when the balloon is filled with liquid. If the gas remains inside the balloon and the liquid and gas become mixed, this can cause problems during treatment using the balloon catheter, and therefore improvement in this regard is desired.

[0006] Therefore, one of the objects of the present disclosure is to provide a technology that can suppress residual gas in a balloon when the balloon is filled with liquid.

[0007] The balloon catheter of the present disclosure comprises a shaft to be inserted into the body, a balloon provided at the distal end portion of the shaft, a heating element capable of heating a liquid supplied into the balloon, and a heating element conductor electrically connected to the heating element, wherein a first lumen through which the heating element conductor is inserted and a second lumen separate from the first lumen are formed inside the shaft, one of the first lumen and the second lumen forming a supply flow path through which the liquid supplied into the balloon flows, and the other of the first lumen and the second lumen forming a discharge flow path through which the fluid discharged from the balloon flows.

[0008] Fig. 2 is an explanatory diagram showing a balloon catheter according to an embodiment; Fig. 3 is a cross-sectional diagram showing a balloon according to an embodiment together with its surrounding structure; Fig. 4 is an explanatory diagram showing a part of a balloon catheter according to an embodiment; Fig. 5 is a cross-sectional diagram taken along line IV-IV in Fig. 2;

[0009] Hereinafter, an embodiment for implementing the balloon catheter of the present disclosure will be described. The same or equivalent elements will be given the same reference numerals, and redundant explanations will be omitted. In each drawing, for the sake of convenience, components will be omitted, enlarged, or reduced in size as appropriate. The drawings should be viewed in accordance with the orientation of the reference numerals.

[0010] Please refer to Figures 1 and 2. First, an overview of the balloon catheter 10 of this embodiment will be described. The balloon catheter 10 of this embodiment is used by heating a liquid (not shown) supplied into a balloon 14 using a heating element 18. The surface temperature of the balloon 14 is adjusted by adjusting the temperature of the liquid inside the balloon 14 using heating by the heating element 18. Treatment (e.g., ablation of biological tissue) is performed using the balloon catheter 10 by bringing the balloon 14, whose surface temperature has been adjusted, into contact with biological tissue. The balloon catheter 10 will be described in detail below.

[0011] The balloon catheter 10 includes a shaft 12, at least the distal portion of which is inserted into the body, a balloon 14 provided at the distal portion of the shaft 12, a handle device 16 provided at the proximal portion of the shaft 12, a heating element 18 capable of heating a liquid supplied into the balloon 14, a heating element lead 20 electrically connected to the heating element 18, and a temperature sensor 22 for detecting the temperature of the balloon 14. In this specification, the direction along the centerline of the shaft 12 is simply referred to as the "axial direction," and the radial and circumferential directions of a circle centered on the centerline of the shaft 12 are simply referred to as the "radial direction" and the "circumferential direction." Furthermore, when illustrating the lead wires 20, 58, sometimes only the centerline is shown, as in Figure 2, and the outlines of the lead wires 20, 58 are omitted.

[0012] See FIG. 1 . The balloon catheter 10 is used for treatment of a living body. Here, "treatment" refers to an action related to medical treatment or examination of a living body. The balloon catheter 10 of this embodiment is shown as being used for ablation of living tissue, but may also be used for other purposes. Organs to be treated with the balloon catheter 10 are not particularly limited, and may be, for example, various organs, such as circulatory organs such as the heart and blood vessels, as well as digestive organs such as the intestinal tract and hepatic duct.

[0013] The handle device 16 includes a handle 24 to which the proximal end portion of the shaft 12 is attached and which is gripped by the surgeon, first and second hub members 26, 28 through which the shaft 12 is inserted, a connector 32 attached to the handle 24 via a first tube 30, and a port member 36 attached to the handle 24 via a second tube 34. An external power supply device 38 and an external measurement device 39, which will be described later, can be electrically connected to the connector 32.

[0014] The first hub member 26 includes a first main pipe 26a through which the shaft 12 is inserted and a first branch pipe 26b branching off from the first main pipe 26a. The second hub member 28 includes a second main pipe 28a through which the shaft 12 is inserted and a second branch pipe 28b branching off from the second main pipe 28a.

[0015] Referring to Figure 2, the shaft 12 is flexible and capable of being bent. The shaft 12 is made up of at least one shaft member 40, 42, 44. The shaft 12 in this embodiment includes a first outer shaft member 40, a second outer shaft member 42, and an inner shaft member 44 as the shaft members 40, 42, 44.

[0016] The first outer shaft member 40 is disposed on the proximal end side, and the second outer shaft member 42 is disposed on the distal end side. The first outer shaft member 40 is formed with a first shaft hole 46 and a second shaft hole 48 that is provided separately from the first shaft hole 46. The first and second shaft holes 46, 48 pass through the first outer shaft member 40 in the axial direction. The proximal end of the first outer shaft member 40 is attached to the handle 24. The second outer shaft member 42 is formed with a shaft hole 50 that passes through the second outer shaft member 42 in the axial direction. In this embodiment, the center line C46 of the first shaft hole 46 is positioned offset from the center line C50 of the shaft hole 50.

[0017] The inner shaft member 44 of this embodiment is inserted through the first shaft hole 46 of the first outer shaft member 40 and also inserted through the shaft hole 50 of the second outer shaft member 42. Although not shown, the inner shaft member 44 of this embodiment is pulled out from the first shaft hole 46 of the first outer shaft member 40 toward the base end inside the handle device 16 and then connected to the port member 36. The inner shaft member 44 includes a base end portion 44a disposed within the first shaft hole 46 of the first outer shaft member 40, a tip end portion 44b disposed within the shaft hole 50 of the second outer shaft member 42, and a connecting portion 44c connecting the base end portion 44a and the tip end portion 44b.

[0018] A device lumen 52 for inserting a medical device such as a guidewire is formed in the inner shaft member 44. The medical device is pulled out from the distal end of the device lumen 52. The medical device is inserted into the device lumen 52 via a device port 54 (see FIG. 1 ) provided in the handle device 16. The device port 54 in this embodiment is provided in the port member 36 of the handle device 16.

[0019] The balloon 14 is inflatable by liquid supplied from the proximal end of the shaft 12. Figures 1 and 2 show the balloon 14 in an inflated state. The balloon 14 includes an expansion section 14a that is inflatable by liquid supplied therein, and sleeve sections 14b provided on both axial sides of the expansion section 14a. The shape of the expansion section 14a is not particularly limited, and may be, for example, spherical. Each sleeve section 14b is attached to a portion of the shaft 12 by welding, adhesive, or the like. Here, an example is shown in which the proximal sleeve section 14b is attached to the first outer shaft member 40, and the distal sleeve section 14b is attached to the second outer shaft member 42.

[0020] The heating element 18 of this embodiment is located within the balloon 14. The heating element 18 of this embodiment is fixed to the shaft 12 within the balloon 14 by adhesive or the like. The heating element 18 of this embodiment is composed of an electrode that heats the liquid by direct resistance heating. The heating element 18 heats the liquid within the balloon 14 using power supplied from an external power supply device 38 (see FIG. 1) via a heating element lead 20. The heating element 18 of this embodiment heats the fluid within the balloon 14 by passing current supplied from the external power supply device 38 through the fluid. The heating mode of the heating element 18 is not particularly limited, and the fluid may be heated by indirect resistance heating, ultrasonic heating, laser heating, microwave heating, or the like. The heating elements 18 of this embodiment are provided in pairs within the balloon 14, spaced apart in the axial direction. The pair of heating elements 18 function as bipolar electrodes that pass current between each other. A total of one heating element conductor 20 is electrically connected to each of the pair of heating elements 18, but the number of conductors 20 connected to the heating elements 18 is not particularly limited. The heating elements 18 are ring-shaped and surround the shaft 12, forming a ring electrode. The shape of the heating elements 18 is not limited to this, and they may be linear, plate-shaped, or the like.

[0021] The heating element conductors 20 electrically connect the heating elements 18 and the external power supply device 38. The heating element conductors 20 are individually provided corresponding to the individual heating elements 18. The tip end of each heating element conductor 20 is electrically connected to the heating element 18 and fixed to the heating element 18 by adhesive or the like.

[0022] The temperature sensor 22 detects the temperature of the balloon 14 itself or the liquid within the balloon 14 as the temperature related to the balloon 14. The balloon catheter 10 of this embodiment is equipped with a total of two temperature sensors 22, although the number is not particularly limited. The temperature sensor 22 includes a temperature detection unit 56 provided on the balloon 14 or within the balloon 14, and a sensor lead 58 electrically connected to the temperature detection unit 56. The temperature sensor 22 of this embodiment is a thermocouple, but may also be a thermistor or the like. In the case of a thermocouple, the temperature detection unit 56 is configured using a temperature measuring junction or the like.

[0023] The temperature detection unit 56 detects an electrical signal indicating the temperature of the balloon 14 or the liquid within the balloon 14 and outputs the electrical signal to the external measurement device 39 via a sensor lead 58. The temperature detection unit 56 of this embodiment is provided in the balloon 14 and detects an electrical signal indicating the temperature of the balloon 14. Alternatively, the temperature detection unit 56 may be provided in the shaft 12 within the balloon 14 and detect an electrical signal indicating the temperature of the liquid within the balloon 14. The external measurement device 39 can measure the temperature of the balloon 14 or the liquid within the balloon 14 by processing the electrical signal detected by the temperature detection unit 56. The two temperature detection units 56 of this embodiment are provided in the balloon 14 at positions on either side of the center line (not shown) of the shaft 12 in the radial direction. The temperature sensor 22 of this embodiment includes a pair of sensor leads 58, each of which is electrically connected to a temperature detection unit 56.

[0024] Please refer to Figures 3 and 4. For ease of explanation, Figure 3 shows only a single heating element lead 20 and a single sensor lead 58. A first lumen 60 and a second lumen 62 separate from the first lumen 60 are formed inside the shaft 12.

[0025] The first lumen 60 in this embodiment is formed between the first shaft hole 46 of the first outer shaft member 40 and the inner shaft member 44. The inner shaft member 44 inserted into the first shaft hole 46 is not essential to forming the first lumen 60 using the first shaft hole 46. Alternatively, the first lumen 60 may be formed inside a lumen tube inserted into the first outer shaft member 40. The first lumen 60 in this embodiment is formed in the axial range from the distal end to the proximal end of the first outer shaft member 40.

[0026] The second lumen 62 in this embodiment is formed by the second shaft hole 48 of the first outer shaft member 40. When the second shaft hole 48 forms the second lumen 62, an inner shaft member may be inserted into the second shaft hole 48. Alternatively, the second lumen 62 may be formed in a lumen tube inserted into the first outer shaft member 40. The second lumen 62 in this embodiment is formed in the axial range from the distal end to the proximal end of the first outer shaft member 40.

[0027] The first and second lumens 60, 62 are formed by a common first outer shaft member 40 that constitutes the shaft 12. A first shaft hole 46 that forms the first lumen 60 and a second shaft hole 48 that forms the second lumen 62 are formed in the common first outer shaft member 40. The inner shaft member 44 is inserted into the first lumen 60 of the first outer shaft member 40.

[0028] A heating element lead wire 20 is inserted through the first lumen 60. In addition, a sensor lead wire 58 is also inserted through the first lumen 60 in this embodiment. Each lead wire 20, 58 is drawn out from the distal end of the first lumen 60 into the balloon 14. The multiple lead wires 20, 58 are electrically connected to the connector 32 after passing through the handle device 16 in addition to the first lumen 60 inside the shaft 12. The multiple heating element lead wires 20 are electrically connected to the external power supply device 38 via the connector 32. The multiple sensor lead wires 58 are electrically connected to the external measurement device 39 via the connector 32.

[0029] One of the first lumen 60 and the second lumen 62 forms at least a portion of a supply flow path 64 through which a liquid supplied to the balloon 14 flows, and the other of the first lumen 60 and the second lumen 62 forms at least a portion of a discharge flow path 66 through which a fluid discharged from the balloon 14 flows. Each of the supply flow path 64 and the discharge flow path 66 is formed inside the shaft 12. The fluid flowing through the discharge flow path 66 here includes both liquid and gas. In this embodiment, the first lumen 60 forms the discharge flow path 66, and the second lumen 62 forms the supply flow path 64. This is not a limitation, and the first lumen 60 may form the supply flow path 64, and the second lumen 62 may form the discharge flow path 66. Furthermore, although the first lumen 60 forms a portion of the discharge flow path 66 in this embodiment, it may also form the entirety of the discharge flow path 66. Similarly, although the second lumen 62 forms a portion of the supply flow path 64 in this embodiment, it may also form the entirety of the supply flow path 64. Similarly, when the first lumen 60 forms the supply flow path 64 and the second lumen 62 forms the discharge flow path 66, each lumen 60, 62 may form part or all of these flow paths 64, 66.

[0030] The supply flow path 64 in this embodiment is defined by the second lumen 62 in the axial range from the tip of the first outer shaft member 40 to the interior of the second hub member 28. The supply flow path 64 in this embodiment is also defined by a side hole 68 formed in the first outer shaft member 40 and communicating with the second lumen 62. Thus, the second lumen 62 in this embodiment forms part of the supply flow path 64. The handle device 16 includes a supply port 70 for supplying liquid to the supply flow path 64. The supply port 70 in this embodiment is provided at the tip of the second branch pipe portion 28b of the second hub member 28. Liquid is supplied to the supply port 70 from a liquid supply device 72, such as an indeflator. This liquid may be, for example, a contrast medium, saline, sterilized water, or other liquids. The liquid supplied from the supply port 70 passes through the interior of the handle device 16 and is then supplied to the supply flow path 64 in the interior of the shaft 12. In this embodiment, liquid supplied from supply port 70 is supplied into supply flow path 64 via the interior of second branch pipe portion 28b of second hub member 28. The gap between second main pipe portion 28a of second hub member 28 and shaft 12 is sealed so that liquid does not flow between second main pipe portion 28a and shaft 12 from the interior of second branch pipe portion 28b.

[0031] The discharge flow path 66 in this embodiment is formed by the first lumen 60 in the axial range from the tip of the first outer shaft member 40 to the interior of the first hub member 26. The discharge flow path 66 in this embodiment is also formed by a side hole 74 formed in the first outer shaft member 40 and communicating with the first lumen 60. Thus, the first lumen 60 in this embodiment forms part of the discharge flow path 66. The handle device 16 includes a discharge port 76 for discharging fluid flowing through the discharge flow path 66 to the outside. The discharge port 76 in this embodiment is provided at the tip of the first branch pipe portion 26b of the first hub member 26. A discharge device 78, such as an indeflator, is connected to the discharge port 76 for drawing in fluid from the balloon 14 and discharging it to the outside. The liquid flowing through the discharge flow path 66 is discharged from the discharge port 76 to the external discharge device 78 via the interior of the handle device 16. In this embodiment, fluid flowing through the discharge flow path 66 is discharged from the discharge port 76 via the inside of the first branch pipe portion 26b of the first hub member 26. The gap between the first main pipe portion 26a of the first hub member 26 and the shaft 12 is sealed so that liquid does not flow between the first main pipe portion 26a and the shaft 12 from the inside of the first branch pipe portion 26b.

[0032] A sealing portion 80 for preventing leakage of liquid to the outside is provided at the base end of each of the lumens 60, 62 that form the supply flow path 64 and the discharge flow path 66. The sealing portion 80 is made of an adhesive or the like that is filled inside each of the lumens 60, 62. The heating element lead wire 20 and the sensor lead wire 58 pass through the sealing portion 80 provided at the base end of the first lumen 60.

[0033] Next, the operation of the balloon catheter 10 will be described. First, the balloon 14 of the balloon catheter 10 is placed at a site to be treated within the body. Then, liquid is supplied from the liquid supply device 72 into the balloon 14 via the supply port 70 and the supply channel 64, filling the balloon 14 with liquid and expanding it. If gas remains in the balloon 14, the liquid is drawn in by the discharge device 78 while the liquid is being supplied into the balloon 14 from the liquid supply device 72. At this time, the liquid in the balloon 14 is drawn in by the discharge device 78 via the discharge channel 66 and the discharge port 76, thereby discharging the gas along with the liquid from the balloon 14. As a result, the balloon 14 remains filled with liquid, and any remaining gas flows through the balloon 14 together with the liquid. During this process, the gas within the balloon 14 can be drawn into the discharge channel 66. At this time, the first lumen 60 is filled with liquid from the proximal end, where the sealing portion 80 is located, to the distal end. The second lumen 62 is also filled with liquid from the proximal end where the sealing portion 80 is located to the distal end.

[0034] The effects of the balloon catheter 10 described above will be explained along with the background that led to the development of the balloon catheter 10 of this embodiment. As mentioned above, the present inventors have newly recognized the following problem when the distal end 60a of the first lumen 60 (see FIG. 3 ) is sealed. Specifically, even if the gas inside the balloon 14 has been sufficiently evacuated in advance, a small amount of gas inside the first lumen 60 proximal to the sealed portion of the distal end 60a of the first lumen 60 can leak into the balloon 14. This is thought to be due to gas leaking from the first lumen 60 through a minute gap that occurs at the sealed portion of the first lumen 60 near the balloon 14. This problem can occur not only before supplying liquid into the balloon 14, but also when filling the balloon 14 with liquid by supplying liquid into the balloon 14.

[0035] As a countermeasure to this problem, the inventors of the present application have recognized that it is effective to use one of the first and second lumens 60, 62 as the supply flow path 64 and the other as the discharge flow path 66, rather than using the second lumen 62 to function both as the supply flow path 64 and the discharge flow path 66. Here, "using the second lumen 62 to function both as the supply flow path 64 and the discharge flow path 66" means using the second lumen 62 as the supply flow path 64 through which liquid is supplied into the balloon 14 and as the discharge flow path 66 through which liquid is discharged from the balloon 14. Consider a case where gas remains in the balloon 14 when the balloon 14 is filled with liquid by supplying liquid into the balloon 14. Even in this case, with the above-described configuration, by supplying liquid through the supply flow path 64 while discharging fluid through the discharge flow path 66, it is possible to discharge the gas from the balloon 14 while keeping the balloon 14 filled with liquid. Furthermore, when the balloon 14 is filled with liquid, the first and second lumens 60, 62 are filled with liquid at locations close to the balloon 14. This prevents gas from leaking into the balloon 14 from the first lumen 60 near the balloon 14 on the proximal side of the sealed location, which occurs when the distal end 60a of the first lumen 60 is sealed. Consequently, it becomes possible to prevent gas from remaining in the balloon 14 when the balloon 14 is filled with liquid.

[0036] If gas remains in the balloon 14, causing the liquid and gas to coexist, the temperature will not rise easily in the areas where the gas is present, resulting in uneven heating, where the temperature of the liquid heated by the heating element 18 will be uneven. If such uneven heating occurs, the surface temperature of the balloon 14 will also be uneven, causing problems during treatment using the balloon catheter 10. For example, when the balloon catheter 10 is used for ablation, this can cause problems such as uneven ablation of biological tissue. In this regard, according to the present embodiment, it is possible to prevent gas from remaining in the balloon 14, thereby preventing uneven heating of the liquid and preventing the problems caused by this.

[0037] Let us consider a case where gas has entered the first lumen 60 through the sealing portion 80 at the proximal end of the first lumen 60. In this case, the sealing portion 80 of the first lumen 60 is located far from the balloon 14, and the gas that has entered through the sealing portion 80 is unlikely to reach the inside of the balloon 14. Therefore, this is more advantageous in terms of preventing gas from remaining in the balloon 14 than when the distal end 60a of the first lumen 60 is sealed.

[0038] The first and second lumens 60, 62 are formed by the common outer shaft member 40 that constitutes the shaft 12. The advantages of this are explained below. If each lumen 60, 62 were formed by a separate member, a lumen tube would be inserted into the outer shaft member 40, and one of the lumens would then be formed inside that lumen tube. In this case, the cross-sectional area of ​​the lumen formed in the lumen tube would be reduced. If an attempt were made to increase the cross-sectional area of ​​each lumen 60, 62 as a countermeasure, this would result in an increased outer diameter of the entire shaft 12, which would be disadvantageous in achieving both.

[0039] In this regard, if the lumens 60, 62 are formed in the common outer shaft member 40, it is not necessary to insert a lumen tube into the interior of the shaft member and then form a lumen inside the lumen tube. This is advantageous for increasing the cross-sectional area of ​​the lumens 60, 62 formed inside the outer shaft member 40. In addition, this is advantageous for achieving both a small outer diameter of the entire shaft 12 and a large cross-sectional area of ​​each of the lumens 60, 62.

[0040] Next, other features of the balloon catheter 10 of this embodiment will be described. In a cross section passing through the shaft 12 and perpendicular to the axial direction, the cross-sectional area S1 (mm ２ ) is the cross-sectional area S2 (mm ２) The cross-sectional areas S1 and S2 of each flow path 64 and 66 refer to the cross-sectional areas of the portions of the cross-section through which liquid can flow. Therefore, when other components such as the conductive wires 20 and 58 are inserted into each flow path 64 and 66, the cross-sectional area excluding these other components is used as the reference. In this embodiment, the cross-sectional area S2 of the discharge flow path 66 is based on the cross-sectional area between the inner circumferential surface of the first lumen 60 of the first outer shaft member 40 and the outer circumferential surface of the inner shaft member 44, excluding the conductive wires 20 and 58. Satisfying this cross-sectional area relationship is advantageous for increasing the instantaneous flow rate of liquid flowing through the supply flow path 64 compared to when S1 < S2. Consequently, increasing the amount of liquid supplied into the balloon 14 is advantageous for quickly filling the balloon 14 with liquid.

[0041] 2 , the supply flow path 64 includes a liquid outlet 64a through which the liquid flows out when the liquid is supplied into the balloon 14. In this embodiment, the liquid outlet 64a is formed on the distal end surface of the first outer shaft member 40, but it may also be formed on the outer peripheral surface thereof. Alternatively, the liquid outlet 64a may be formed on a lumen tube other than the outer shaft member 40. The discharge flow path 66 includes a liquid inlet 66a through which the liquid flows in when the liquid is discharged from the balloon 14. In this embodiment, the liquid inlet 66a is formed on the distal end surface of the first outer shaft member 40, but it may also be formed on the outer peripheral surface thereof. Alternatively, the liquid inlet 66a may be formed on a lumen tube other than the outer shaft member 40.

[0042] The liquid outlet 64a of the supply flow path 64 in this embodiment is located closer to the base end of the shaft 12 than the expansion portion 14a of the balloon 14. Additionally, the liquid inlet 66a of the discharge flow path 66 in this embodiment is located closer to the base end of the shaft 12 than the expansion portion 14a of the balloon 14. This makes it easier to effectively draw gas remaining on the base end side of the balloon 14 into the discharge flow path 66 from the liquid inlet 66a when discharging gas from the balloon 14. Furthermore, as described above, by supplying liquid to the balloon 14 from the supply flow path 64 while discharging it from the discharge flow path 66, the gas remaining in the balloon 14 can be caused to flow together with the liquid. This makes it easier to draw gas remaining on the tip side of the balloon 14 into the discharge flow path 66 from the liquid inlet 66a. This is advantageous for discharging gas from the balloon 14.

[0043] Next, variations of the components described above will be described.

[0044] There are no particular limitations on the specific example of the shaft 12. For example, the shaft 12 may be composed of only one shaft member, or may be composed of two or more shaft members. Furthermore, the shaft 12 may be composed of one outer shaft member 40 and one inner shaft member 44.

[0045] The number of heating members 18 is not particularly limited, and may be one or three or more, in addition to two as in the embodiment. The heating member 18 may function as a monopolar electrode that conducts electricity between itself and a return electrode outside the body. The heating member 18 may be provided on the shaft 12 outside the balloon 14.

[0046] The locations of the connector 32, device port 54, supply port 70, and discharge port 76 provided in the handle device 16 are not particularly limited. For example, they may be provided in the handle 24. In this case, the hub members 26, 28 may be omitted. Also, although the handle 24 and the hub members 26, 28 are provided separately in the embodiment, they may also be provided as an integrated unit.

[0047] The first lumen 60 and the second lumen 62 may be formed in separate members including the shaft member. The cross-sectional area S1 of the supply flow path 64 may be equal to or smaller than the cross-sectional area S2 of the discharge flow path 66. The position of the liquid inlet 66a of the discharge flow path 66 within the balloon 14 is not particularly limited. For example, the liquid inlet 66a may be provided within the expansion portion 14a of the balloon 14.

[0048] The above-described embodiments and variations are merely examples. The abstract technical concepts should not be interpreted as being limited to the content of the embodiments and variations. Many design modifications, such as changes, additions, and deletions of components, are possible in the content of the embodiments and variations. In the above-described embodiments, the terms "embodiment" and "present embodiment" are used to emphasize the content in which such design modifications are possible. However, design modifications are also permitted even in content without such notation. Hatching on cross sections in the drawings does not limit the material of the hatched object. Any combination of the above-described components is also valid. For example, any description of another embodiment may be combined with an embodiment, or any description of an embodiment and another variation may be combined with a variation.

[0049] The present disclosure relates to balloon catheters.

[0050] 10...balloon catheter, 12...shaft, 14...balloon, 14a...expansion portion, 18...heating element, 20...heating element lead wire, 22...temperature sensor, 40...outer shaft member, 44...inner shaft member, 52...device lumen, 56...temperature detection portion, 58...sensor lead wire, 60...first lumen, 62...second lumen, 64...supply flow path, 66...discharge flow path, 66a...liquid inlet

Claims

1. A balloon catheter comprising a shaft to be inserted into the body, a balloon provided at a tip side portion of the shaft, a heating member capable of heating a liquid supplied into the balloon, and a wire for the heating member electrically connected to the heating member, wherein a first lumen through which the wire for the heating member is inserted and a second lumen different from the first lumen are formed inside the shaft, and one of the first lumen and the second lumen forms at least a part of a supply flow path through which the liquid supplied into the balloon flows, and the other of the first lumen and the second lumen forms at least a part of a discharge flow path through which the fluid discharged from the balloon flows.

2. The balloon catheter according to claim 1, further comprising a temperature sensor having the balloon or a temperature detection unit provided in the balloon, and a wire for the sensor connected to the temperature detection unit, wherein both the wire for the heating member and the wire for the sensor are inserted into the first lumen.

3. The balloon catheter according to claim 1 or 2, wherein the shaft includes an outer shaft member forming the first lumen and an inner shaft member inserted into the first lumen and having a device lumen formed therein for inserting a medical device.

4. The balloon catheter according to any one of claims 1 to 3, wherein the first lumen and the second lumen are formed by a common shaft member constituting the shaft.

5. The balloon catheter according to any one of claims 1 to 4, wherein in a cross section orthogonal to the axial direction of the shaft, the cross-sectional area of the supply flow path is larger than the cross-sectional area of the discharge flow path.

6. The balloon catheter according to any one of claims 1 to 5, wherein the balloon includes an expansion portion expandable by the liquid supplied into the balloon, and a liquid inlet of the discharge flow path is provided on a proximal end side of the shaft with respect to the expansion portion.

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