Cryoablation catheter for duodenal papilla insertion and cryoablation catheter system

Abstract

A cryoablation catheter (1) and a cryoablation catheter system provided with the cryoablation catheter (1), the cryoablation catheter (1) for duodenal papilla insertion being provided with: an outer tube (10); a cryoablation catheter (1) includes an outer tube (10) having a lumen (15), and a first inner tube (210) disposed in the lumen (15) of the outer tube (10), the first inner tube (210) having a guidewire lumen (211) and a plurality of supply lumens (212), the cryoablation catheter (1) having a first discharge flow path (31) between an inner surface (14) of the outer tube (10) and an outer surface (213) of the first inner tube (210), and a hole (40) formed in a distal portion of the first inner tube (210) and communicating the supply lumens (212) and the first discharge flow path (31).

Description

Technical Field

[0001] The invention relates to a cryoablation catheter for inserting into the duodenal papilla and a cryoablation catheter system. Background Art

[0002] Cryoablation is a medical technique that freezes and necrotizes cells that make up the target tissue by bringing a low-temperature device into contact with the target tissue. It is used in the treatment of myocardial tissue and tumor tissue. There are methods for lowering the temperature of the device, such as a method using liquid nitrogen and a method using the Joule-Thomson effect based on high-pressure gas.

[0003] Patent Document 1 describes a cryosurgery catheter having a catheter body having a proximal end, a distal end, and a main lumen penetrating therethrough. A balloon is placed on a throttle hole of the catheter body constituting the cryosurgery catheter, and the balloon receives a cryogenic fluid supplied through the main lumen. The cryogenic fluid is supplied to the balloon through the catheter body, thereby expanding the balloon and cooling the affected part.

[0004] Patent Document 1: Japanese Patent Application No. 2001-524345

[0005] In order to freeze the inner cavity tissue that is closer to the liver side, gallbladder side or pancreas side than the duodenal papilla, it is necessary to insert a catheter into the duodenal papilla. For example, when inserting a catheter into the bile duct via the duodenal papilla, the catheter needs to be bent significantly when moving from the duodenal side to the bile duct side. The catheter for cryoablation described in Patent Document 1 is designed so that the area of ​​contact between the refrigerant and the wall surface of the catheter constituting the inner cavity is as small as possible. Therefore, generally only one inner cavity is formed for supplying fluid. Using only one inner cavity for supplying fluid is also to make it easier to reduce the diameter of the catheter so that it can be inserted into a thinner body cavity. However, in existing catheters that are only formed with one inner cavity for supplying fluid, when passing through a portion with a large bending angle such as the duodenal papilla, the catheter bends, resulting in occlusion of the low-temperature fluid supply inner cavity, and the fluid cannot be stably delivered. Summary of the invention

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cryoablation catheter for insertion into the duodenal papilla and a cryoablation catheter system that can stably deliver a fluid from the proximal side to the distal side.

[0007] A cryoablation catheter for insertion into the duodenal papilla according to one embodiment of the present invention is as follows.

[0008] [1] A cryoablation catheter for insertion into the duodenal papilla, comprising: an outer tube having a distal end and a proximal end and extending in a length direction; and a first inner tube extending in the length direction and disposed in an inner cavity of the outer tube, wherein:

[0009] In a cross section perpendicular to the longitudinal direction, the first inner tube comprises: a guidewire lumen for inserting the guidewire; and a plurality of supply lumens formed in a region different from the guidewire lumen and capable of supplying fluid from the proximal side toward the distal side of the first inner tube.

[0010] The cryoablation catheter has a first discharge flow path between the inner surface of the outer tube and the outer surface of the first inner tube, and the first discharge flow path allows the fluid to pass from the distal side of the outer tube to the proximal side.

[0011] A hole that connects the supply lumen and the first discharge flow path is formed in the distal portion of the first inner tube.

[0012] The first inner cylinder of the cryoablation catheter for insertion into the duodenal papilla of the present invention is formed with a plurality of supply lumens. Therefore, even if one supply lumen is blocked due to bending of the cryoablation catheter when passing through a portion with a large bending angle such as the duodenal papilla, fluid can be delivered through the remaining supply lumens. Thus, fluid can be delivered stably from the proximal side to the distal side.

[0013] The cryoablation catheter for insertion into the duodenal papilla according to the embodiment of the present invention is preferably any one of the following [2] to

[15] .

[0014] [2] The cryoablation catheter according to [1], wherein:

[0015] In a cross section perpendicular to the longitudinal direction, an eccentric distance of the centroid of the supply lumen relative to the centroid of the first inner tube is greater than an eccentric distance of the centroid of the guidewire lumen relative to the centroid of the first inner tube.

[0016] [3] The cryoablation catheter according to [1] or [2], wherein:

[0017] In a cross section perpendicular to the longitudinal direction, the guide wire lumen is formed at a position overlapping with the centroid of the first inner tube, and the supply lumen is formed at a position not overlapping with the centroid of the first inner tube.

[0018] [4] The cryoablation catheter according to any one of [1] to [3], wherein:

[0019] The first inner cylinder is integrally formed of a predetermined material.

[0020] [5] The cryoablation catheter according to any one of [1] to [4], wherein:

[0021] The above-mentioned hole is formed in plurality.

[0022] In a cross section perpendicular to the longitudinal direction, there is only one hole on a straight line passing through the centroid of the first inner cylinder.

[0023] [6] The cryoablation catheter according to any one of [1] to [5], wherein:

[0024] In a cross section perpendicular to the longitudinal direction, there is only one supply lumen on a straight line passing through the centroid of the first inner cylinder and the hole.

[0025] [7] The cryoablation catheter according to any one of [1] to [6], wherein:

[0026] In a cross section perpendicular to the longitudinal direction, the plurality of supply lumens are located on an imaginary circle centered at the centroid of the first inner cylinder.

[0027] [8] The cryoablation catheter according to any one of [1] to [7], wherein:

[0028] The outer tube has a balloon at a distal portion of the outer tube that is expandable and contractible in a radial direction of the outer tube.

[0029] [9] The cryoablation catheter according to [8], wherein:

[0030] The thermal conductivity of the material constituting the balloon is higher than the thermal conductivity of the material constituting the portion other than the balloon in the outer tube.

[0031]

[10] The cryoablation catheter according to any one of [1] to [9], wherein:

[0032] The above-mentioned fluid is gas.

[0033]

[11] The cryoablation catheter according to any one of [1] to

[10] , wherein:

[0034] In a cross section perpendicular to the longitudinal direction, the first inner cylinder comprises: a first supply lumen; and a second supply lumen formed beside the first supply lumen in the circumferential direction of the first inner cylinder.

[0035] In a cross section perpendicular to the longitudinal direction, an angle α formed by a ray having the centroid of the first inner cylinder as one end and passing through the centroid of the first supply lumen and a ray having the centroid of the first inner cylinder as one end and passing through the centroid of the second supply lumen is greater than 105 degrees and less than 135 degrees.

[0036]

[12] The cryoablation catheter according to any one of [1] to

[11] , wherein:

[0037] The cryoablation catheter has a second inner tube extending in the longitudinal direction and arranged in the inner cavity of the outer tube at a position closer to the first inner tube.

[0038] The second inner cylinder comprises: a 2-1 inner cylinder extending along the length direction; and a 2-2 inner cylinder disposed in the inner cavity of the 2-1 inner cylinder and extending along the length direction.

[0039] There is a 2-1 flow path between the inner surface of the 2-1 inner cylinder and the outer surface of the 2-2 inner cylinder, and the 2-1 flow path is connected to a plurality of supply cavities formed in the 1st inner cylinder.

[0040] The inner lumen of the 2-2 inner tube is communicated with the guide wire inner lumen formed in the first inner tube.

[0041]

[13] The cryoablation catheter according to

[12] , wherein:

[0042] The cryoablation catheter has a third inner tube extending in the longitudinal direction and arranged in the inner cavity of the outer tube at a position closer to the second inner tube.

[0043] In a cross section perpendicular to the length direction, the third inner tube comprises: a 3-1 inner cavity extending along the length direction and connected to the 2-1 flow path; and a 3-2 inner cavity formed in a region different from the 3-1 inner cavity and connected to the inner cavity of the 2-2 inner tube.

[0044]

[14] The cryoablation catheter according to

[13] , wherein:

[0045] The cryoablation catheter has a fourth inner tube extending in the longitudinal direction and arranged in the inner cavity of the outer tube at a position closer to the third inner tube.

[0046] The inner cavity of the fourth inner cylinder is communicated with the inner cavity of the third-1.

[0047]

[15] The cryoablation catheter according to any one of [1] to

[14] , wherein:

[0048] The cryoablation catheter further comprises a front end tip, the front end tip is formed with an inner cavity extending along the length direction, and the outer diameter decreases from the proximal side to the distal side.

[0049] The distal end portion of the outer tube and the distal end portion of the first inner tube are fixed to the proximal end portion of the front end tip.

[0050] The present invention further provides the following technical solutions.

[0051]

[16] A cryoablation catheter system comprising: a cryoablation catheter as described in any one of [1] to

[15] ; and a fluid supply device for supplying the fluid to the supply lumen, wherein:

[0052] The first inner cylinder is connected to the fluid supply device.

[0053] The first inner cylinder of the cryoablation catheter for insertion into the duodenal papilla of the present invention is formed with a plurality of supply lumens. Therefore, even if one supply lumen is blocked due to the bending of the cryoablation catheter when passing through a portion with a large bending angle such as the duodenal papilla, fluid can be delivered through the remaining supply lumens. Thus, fluid can be stably delivered from the proximal side to the distal side. The cryoablation catheter system of the present invention having the above-mentioned cryoablation catheter for insertion into the duodenal papilla also has the same effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A side view showing an example of a cryoablation catheter according to an embodiment of the present invention is shown.

[0055] Figure 2 express Figure 1 A cross-sectional view of a cryoablation catheter is shown.

[0056] Figure 3 express Figure 2 A cross-sectional view of line III-III of the cryoablation catheter is shown.

[0057] Figure 4 express Figure 2 An end view of the cut portion of the cryoablation catheter taken along line IV-IV is shown.

[0058] Figure 5 express Figure 2 The end view of the cut section of the cryoablation catheter shown is taken along line VV.

[0059] Figure 6 express Figure 2 The end view of the cut portion of the cryoablation catheter shown is taken along line VI-VI.

[0060] Figure 7 Indicates Figure 2 A cross-sectional view of a modified example of a cryoablation catheter is shown.

[0061] Figure 8 express Figure 7 A cross-sectional view of line VIII-VIII of the cryoablation catheter is shown.

[0062] Fig. 9 express Figure 7 The end view of the cut portion of the cryoablation catheter shown is taken along line IX-IX.

[0063] Fig.10 express Figure 7 The end view of the cut portion of the cryoablation catheter shown is taken along line XX.

[0064] Fig.11 A side view showing a modified example of the cryoablation catheter according to the embodiment of the present invention is shown.

[0065] Fig.12 express Fig.11 A cross-sectional view of a cryoablation catheter is shown.

[0066] Fig.13 express Fig.12 A cross-sectional view of the cryoablation catheter taken along line XIII-XIII is shown.

[0067] Fig.14 express Fig.12 The cryoablation catheter is shown as an end view of the cut portion taken along line XIV-XIV.

[0068] Fig.15 express Figure 2 A cross-sectional view of the cryoablation catheter taken along line XV-XV is shown.

[0069] Fig.16 express Figure 2 A cross-sectional view of the cryoablation catheter taken along line XVI-XVI is shown. DETAILED DESCRIPTION

[0070] Hereinafter, the present invention will be specifically described with reference to the accompanying drawings, but the present invention is of course not limited to the illustrated examples, and can also be implemented by appropriately changing the scope of the subject matter described above / below, which are all included in the technical scope of the present invention. In each figure, hatching, reference numerals, etc. are omitted for convenience. In this case, please refer to the specification and other drawings. In addition, the dimensions of various components in the drawings are preferentially conducive to understanding the features of the present invention, and therefore may be different from the actual dimensions.

[0071] The cryoablation catheter involved in one embodiment of the present invention is a cryoablation catheter for insertion into the duodenal papilla, comprising: an outer tube, which has a distal end and a proximal end and extends along the length direction; and a first inner tube, which extends along the length direction of the outer tube and is arranged in the inner cavity of the outer tube, and has the following points, namely: in the cross-section of the outer tube perpendicular to the length direction, the first inner tube has: a guide wire lumen for inserting the guide wire; and a plurality of supply lumens, which are formed in a region different from the guide wire lumen and can allow fluid to pass from the proximal side of the first inner tube to the distal side, and the cryoablation catheter has a first discharge flow path between the inner surface of the outer tube and the outer surface of the first inner tube, and the first discharge flow path can allow the above-mentioned fluid to pass from the distal side of the outer tube to the proximal side, and a hole connecting the supply lumen with the first discharge flow path is formed in the distal part of the first inner tube.

[0072] Reference Figures 1 to 16 The overall structure of the cryoablation catheter 1 according to the embodiment of the present invention will be described. Figure 2 , Figure 3 , Figure 7 , Figure 8 , Figure 12 to Figure 14 , a cryoablation catheter 1 having an outer tube 10 and a first inner tube 210 is shown. In this figure, x represents the length direction of the outer tube 10, and y represents the radial direction. The radial direction y is a direction perpendicular to the length direction x. In addition, z represents the circumferential direction of the outer tube 10. In addition, the cryoablation catheter 1 is sometimes referred to as the catheter 1 below.

[0073] In this specification, the proximal side refers to the user's hand side in the extension direction of the outer cylinder, and the distal side refers to the opposite side of the proximal side, that is, the treatment object side. In addition, the distal portion of each component refers to the distal half of each component, and the proximal portion of each component refers to the proximal half of each component.

[0074] Figure 1 A side view showing an example of a cryoablation catheter according to an embodiment of the present invention is shown. Figure 2 express Figure 1 A cross-sectional view of a cryoablation catheter is shown. Figure 3 express Figure 2 A cross-sectional view of line III-III of the cryoablation catheter is shown. Figure 4 express Figure 2 An end view of the cut portion of the cryoablation catheter taken along line IV-IV is shown. Figure 5 express Figure 2 The end view of the cut section of the cryoablation catheter shown is taken along line VV. Figure 6 express Figure 2 The end view of the cut portion of the cryoablation catheter shown is taken along line VI-VI. Figure 7 Indicates Figure 2A cross-sectional view of a modified example of a cryoablation catheter is shown. Figure 8 express Figure 7 A cross-sectional view of line VIII-VIII of the cryoablation catheter is shown. Fig. 9 express Figure 7 The end view of the cut portion of the cryoablation catheter shown is taken along line IX-IX. Fig.10 express Figure 7 The end view of the cut portion of the cryoablation catheter shown is taken along line XX. Fig.11 A side view showing a modified example of the cryoablation catheter according to the embodiment of the present invention is shown. Fig.12 express Fig.11 A cross-sectional view of a cryoablation catheter is shown. Fig.13 express Fig.12 A cross-sectional view of the cryoablation catheter taken along line XIII-XIII is shown. Fig.14 express Fig.12 The cryoablation catheter is shown as an end view of the cut portion taken along line XIV-XIV. Fig.15 express Figure 2 A cross-sectional view of the cryoablation catheter taken along line XV-XV is shown. Fig.16 express Figure 2 A cross-sectional view of the cryoablation catheter taken along line XVI-XVI is shown.

[0075] The cryoablation catheter involved in the embodiment of the present invention is a cryoablation catheter for insertion into the duodenal papilla, which means that the cryoablation catheter for insertion into the duodenal papilla is connected to the opening of the duodenal papilla and inserted into the duodenal papilla in order to freeze the lumen tissue located on the liver side, gallbladder side or pancreas side of the duodenal papilla.

[0076] like Figure 1 to Figure 3 , Figure 7 , Figure 8 As shown, the catheter 1 has an outer tube 10, which has a distal end 11 and a proximal end 12 and extends along a length direction x. The outer tube 10 has an inner cavity 15. Preferably, the inner cavity 15 extends along the length direction x of the outer tube 10. The outer tube 10 has an outer surface 13 facing the outside of the outer tube 10 and an inner surface 14 facing the inner cavity 15 of the outer tube 10.

[0077] like Figure 1 to Figure 3 , Figure 7 , Figure 8 As shown, the catheter 1 includes a first inner tube 210, which extends along the length direction x of the outer tube 10 and is arranged in the inner cavity 15 of the outer tube 10. Figure 3 , Figure 8As shown, in a cross section perpendicular to the length direction x of the outer tube 10, the first inner tube 210 comprises: a guidewire lumen 211 for inserting a guidewire; and a plurality of supply lumens 212, which are formed in an area different from the guidewire lumen 211 and capable of allowing fluid to pass from the proximal side of the first inner tube 210 toward the distal side.

[0078] like Figure 2 , Figure 3 , Figure 7 , Figure 8 As shown, the catheter 1 has a first discharge flow path 31 between the inner surface 14 of the outer tube 10 and the outer surface 213 of the first inner tube 210, and the first discharge flow path 31 can allow the fluid to pass from the distal side of the outer tube 10 to the proximal side. The first discharge flow path 31 is a space provided between the inner surface 14 of the outer tube 10 and the outer surface 213 of the first inner tube 210. The fluid transported from the proximal side to the distal side of the catheter 1 by passing through the supply lumen 212 is discharged to the outside of the catheter 1 through the first discharge flow path 31, which is a space provided between the inner surface 14 of the outer tube 10 and the outer surface 213 of the first inner tube 210.

[0079] like Figure 2 , Figure 3 , Figure 7 , Figure 8 As shown in FIG. 1 , a hole 40 is formed at the distal portion of the first inner tube 210 to connect the supply lumen 212 with the first discharge flow path 31. The fluid transported from the proximal side to the distal side of the catheter 1 through the supply lumen 212 is ejected toward the first discharge flow path 31 via the hole 40. Figure 2 , Figure 7 As shown, the hole 40 may be formed not only in the distal portion of the first inner tube 210 but also in the proximal portion of the first inner tube 210. Fig.12 As shown, the hole 40 may be formed only in the distal portion of the first inner tube 210 .

[0080] After the fluid is transported from the proximal side to the distal side of the catheter 1 through the supply lumen 212, it is ejected radially outward from the hole 40 of the first inner tube 210 of the outer tube 10, and after being transported from the distal side to the proximal side through the first discharge flow path 31, it is discharged to the outside of the catheter 1.

[0081] The first inner cylinder 210 of the cryoablation catheter 1 for insertion into the duodenal papilla of the present invention is formed with a plurality of supply lumens 212. Therefore, even if one supply lumen 212 is blocked due to the bending of the cryoablation catheter 1 when passing through a site with a large bending angle such as the duodenal papilla, fluid can be supplied through the remaining supply lumens 212. Thus, fluid can be stably supplied from the proximal side to the distal side.

[0082] The outer tube 10 is preferably flexible in order to be inserted into the body. This allows the outer tube 10 to be deformed along the shape of the body cavity. In addition, the outer tube 10 is preferably elastic in order to maintain its shape.

[0083] For the outer cylinder 10, there can be cited a hollow body formed by arranging one or more wires in a prescribed pattern; a structure formed by coating a resin on at least one of the inner surface or the outer surface of the above-mentioned hollow body; a resin tube; or a structure formed by combining them, such as a structure formed by connecting them in the long axis direction. As a hollow body formed by arranging wires in a prescribed pattern, a cylindrical body having a mesh structure by simply crossing or weaving the wires, and a coil wound with wires are shown. The wires can be one or more single wires, or one or more twisted wires. The resin tube can be manufactured, for example, by extrusion molding. In the case where the outer cylinder 10 is a resin tube, the outer cylinder 10 can be composed of a single layer or multiple layers. A portion of the outer cylinder 10 in the longitudinal direction x or the circumferential direction z may be composed of a single layer, and another portion may be composed of multiple layers.

[0084] The outer cylinder 10 can be made of, for example, synthetic resins such as polyolefin resins (e.g., polyethylene, polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyetherketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, fluororesins (e.g., PTFE, PFA, ETFE), and metals such as stainless steel, carbon steel, and nickel-titanium alloys. These can be used alone or in combination of two or more.

[0085] The outer tube 10 is in a cylindrical shape, and can be in a hollow cylindrical shape, a hollow polygonal column shape, or the like.

[0086] like Figure 1 , Figure 2 , Figure 7 , Fig.15 As shown in FIG. 1 , an X-ray opaque marker 70 may be provided at the distal portion of the outer tube 10. By forming such a structure, the position of the distal portion of the catheter 1 can be visually confirmed by using an X-ray imaging device. Figure 1 , Figure 2 , Fig.15 As shown, the X-ray opaque markers 70 may also be disposed on the outer surface 13 of the outer cylinder 10 .

[0087] like Fig.12 As shown, an X-ray opaque marker 70 may be provided at the distal portion of the first inner tube 210. With this configuration, the position of the distal portion of the catheter 1 can be visually confirmed by using an X-ray imaging device.

[0088] like Figure 1 , Figure 2 , Fig.15As shown, the shape of the radiopaque marker 70 is preferably a tube. Other shapes include a hollow cylindrical shape, a hollow polygonal column shape, a C-shaped cross-section with a cutout formed in a tube, and a coiled shape with a wire wound thereon.

[0089] As a material constituting the above-mentioned X-ray opaque marker 70, for example, an X-ray opaque substance such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, cobalt-chromium alloy, etc. can be used. In addition, it is also possible to disperse X-ray opaque particles such as barium sulfate in the outer cylinder 10, the first inner cylinder 210, or a separately provided resin member.

[0090] like Figure 11 to Figure 13 As shown, the outer tube 10 preferably has a balloon 50 at a distal portion of the outer tube 10 that can expand and contract in the radial direction y of the outer tube 10 . Figure 11 to Figure 13 The balloon 50 is shown in a state where the diameter is expanded. Preferably, the balloon 50 is configured so that the diameter is expanded by supplying a fluid into the balloon 50 and the diameter is reduced by removing the fluid.

[0091] When the outer tube 10 has the balloon 50, the portion of the outer tube 10 constituting the balloon 50 and the portion other than the balloon 50 may be separate components, and the outer tube 10 may be formed by combining them. Fig.11 , Fig.12 As shown, the outer tube 10 may include the balloon 50 and the tubular member 16. When the outer tube 10 includes the balloon 50, the portion of the outer tube 10 that includes the balloon 50 and the portion other than the balloon 50 may be integrally formed.

[0092] In the case where the catheter 1 has the balloon 50, the fluid is transported from the proximal side to the distal side of the catheter 1 through the supply lumen 212, and after being ejected from the hole 40 of the first inner tube 210 to the radially outer side of the outer tube 10 to expand the diameter of the balloon 50, it is transported from the distal side to the proximal side through the first discharge flow path 31 and discharged to the outside of the catheter 1. When the diameter of the balloon 50 is expanded, the outer surface of the balloon 50 contacts the wall of a biological vessel such as a blood vessel and a digestive tract, thereby stabilizing the position of the catheter 1 in the body cavity. In addition, since the outer surface of the balloon 50 contacts the wall of a biological vessel such as a blood vessel and a digestive tract, it is easy to freeze the tissue contacted by the outer surface of the balloon 50.

[0093] The balloon 50 is expanded in diameter by the fluid injected from the hole 40 toward the radially outer side of the outer tube 10, and is reduced in diameter by the discharge of the fluid. Fig.11 , Fig.12As shown, in the state where the balloon 50 is in an expanded state, the balloon 50 may include: a straight tube portion 51 having a substantially cylindrical shape; a distal tapered portion 52 located at a position closer to the distal side than the straight tube portion 51, and having an outer diameter that decreases toward the distal side; and a proximal tapered portion 53 located at a position closer to the proximal side than the straight tube portion 51, and having an outer diameter that decreases toward the proximal side. In addition, the balloon 50 may also include: a distal sleeve portion 54 located at a position closer to the distal side than the distal tapered portion 52, which is not expanded by the fluid injected from the hole 40 to the radially outer side of the outer tube 10, and is fixed to the outer surface 213 of the first inner tube 210; and a proximal sleeve portion 55 located at a position closer to the proximal side than the proximal tapered portion 53, which is not expanded by the fluid injected from the hole 40 to the radially outer side of the outer tube 10, and is fixed to the outer surface of the tubular member 16.

[0094] The material constituting the balloon 50 in the outer tube 10 and the material constituting the portion other than the balloon 50 in the outer tube 10 may be the same as or different from each other, but the thermal conductivity of the material constituting the balloon 50 is preferably higher than the thermal conductivity of the material constituting the portion other than the balloon 50 in the outer tube 10. Thus, the temperature of the balloon 50 portion in the outer tube 10 is easier to decrease than the temperature of the portion other than the balloon 50, and thus the freezing efficiency of the tissue at the portion where the balloon 50 is disposed is easier to increase.

[0095] like Fig.12 As shown, the hole 40 is preferably located inside the balloon 50. That is, the hole 40 is preferably formed in the portion of the first inner tube 210 located inside the balloon 50. The hole 40 may also be formed in a portion of the first inner tube 210 that is not located inside the balloon 50, but it is preferred that the hole 40 be formed only in the portion of the first inner tube 210 that is located inside the balloon 50. As a result, the temperature of the balloon 50 in the outer tube 10 is easily lowered compared to the temperature of the portion outside the balloon 50, and thus the freezing efficiency of the tissue at the portion where the balloon 50 is arranged is easily increased.

[0096] like Figure 2 , Figure 7 , Fig.12 As shown, it is preferred that a plurality of X-ray opaque marks 70 are provided in the length direction x of the outer cylinder 10, one X-ray opaque mark 70 is located at a position on the distal side of the hole 40, and another X-ray opaque mark 70 is located at a position on the proximal side of the hole 40. Thus, the position of the hole 40 can be easily identified by using an X-ray imaging device.

[0097] like Fig.12 As shown, an X-ray opaque marker 70 may also be provided on the outer surface 213 of the first inner tube 210 at the position where the distal end and the proximal end of the straight tube portion 51 of the balloon 50 are located in the length direction x of the outer tube 10. Alternatively, although Fig.12Although not shown in the figure, an X-ray opaque mark 70 may be provided on the outer surface 213 of the first inner tube 210 at the center of the straight tube 51 of the balloon 50 in the longitudinal direction x of the outer tube 10. With this structure, the position of the straight tube 51 of the balloon 50 can be visually confirmed by using an X-ray imaging device.

[0098] The first inner cylinder 210 has a guide wire lumen 211 and a supply lumen 212. Preferably, the guide wire lumen 211 and the supply lumen 212 extend along the length direction x of the outer cylinder 10. The first inner cylinder 210 has: an outer surface 213 of the outer side of the first inner cylinder 210, that is, facing the outer cylinder 10 side; and an inner surface 214 facing the guide wire lumen 211. Figure 2 As shown, the guide wire lumen 211 is preferably connected to the lumen 63 of the front end tip 60 described later.

[0099] As a material constituting the first inner cylinder 210, synthetic resin, metal, etc. similar to those of the outer cylinder 10 can be used. The material constituting the first inner cylinder 210 and the material constituting the outer cylinder 10 may be the same or different.

[0100] It is preferred that the first inner cylinder 210 is integrally formed of a prescribed material. The prescribed material includes a material produced by mixing a plurality of substances and a material consisting of only a single substance. For example, the first inner cylinder 210 can be integrally formed by extrusion molding using a prescribed material. Since the first inner cylinder 210 is integrally formed of a prescribed material, there are no joints between parts, and thus it is not easy to form a portion with high rigidity and a portion with low rigidity. Therefore, it is easy to suppress the bending of the first inner cylinder 210 when passing through a portion with a large bending angle such as the duodenal papilla, and it is easy to suppress the occlusion of the supply lumen 212. In addition, if it is designed to be integrally formed of a prescribed material, it is not necessary to manufacture a plurality of parts, and thus the manufacturing process of the first inner cylinder 210 can be facilitated, and the time and cost required for manufacturing can be suppressed.

[0101] like Figure 1 , Figure 2 , Figure 7 As shown, the first inner tube 210 may extend only toward the distal side of the proximal end 12 of the outer tube 10 . Figure 1 , Figure 2 , Figure 7 The catheter 1 shown is a so-called rapid exchange catheter.

[0102] like Fig.11 , Fig.12 As shown, the first inner cylinder 210 may also extend over the entire length of the outer cylinder 10 . Fig.11 , Fig.12 The catheter 1 shown is a so-called integral exchange catheter.

[0103] like Figure 3As shown, it is preferred that, in a cross section perpendicular to the length direction x of the outer cylinder 10, the eccentric distance of the centroid 212c of the supply lumen 212 relative to the centroid 210c of the first inner cylinder 210 is greater than the eccentric distance of the centroid 211c of the guide wire lumen 211 relative to the centroid 210c of the first inner cylinder 210. The eccentric distance of the centroid 212c of the supply lumen 212 relative to the centroid 210c of the first inner cylinder 210 refers to the distance from the centroid 212c of the supply lumen 212 when the centroid 210c of the first inner cylinder 210 is the center. The eccentric distance of the centroid 211c of the guide wire lumen 211 relative to the centroid 210c of the first inner cylinder 210 refers to the distance from the centroid 211c of the guide wire lumen 211 when the centroid 210c of the first inner cylinder 210 is the center. By making the eccentric distance of the centroid 212c of the supply lumen 212 relative to the centroid 210c of the first inner tube 210 greater than the eccentric distance of the centroid 211c of the guide wire lumen 211 relative to the centroid 210c of the first inner tube 210, the supply lumen 212 is formed radially outward of the first inner tube 210 relative to the guide wire lumen 211. Thus, the fluid delivered to the distal side via the supply lumen 212 can be ejected to the first discharge flow path 31 via the hole 40 relatively early, so that the tissue to be treated can be easily and efficiently cooled.

[0104] like Figure 3 As shown, it is preferred that in a cross section perpendicular to the longitudinal direction x of the outer tube 10, the guide wire lumen 211 is formed at a position overlapping with the centroid 210c of the first inner tube 210, and the supply lumen 212 is formed at a position not overlapping with the centroid 210c of the first inner tube 210. Since the guide wire lumen 211 is formed at a position overlapping with the centroid 210c of the first inner tube 210, and the supply lumen 212 is formed at a position not overlapping with the centroid 210c of the first inner tube 210, the supply lumen 212 is formed radially outward of the first inner tube 210 relative to the guide wire lumen 211. Thus, the fluid delivered to the distal side through the supply lumen 210 can be ejected to the first discharge flow path 31 relatively early via the hole 40, so that the tissue to be treated can be easily and efficiently cooled. Furthermore, since the guidewire lumen 211 is formed at a position overlapping with the centroid 210 c of the first inner tube 210 , the guidewire is easily positioned at the axial center of the first inner tube 210 , and thus the operability of the catheter 1 can be easily improved.

[0105] The shape of the hole 40 can be circular, oval, polygonal, etc. There can be one hole 40 or a plurality of holes 40. The plurality of holes 40 can all be of the same shape or each hole 40 can be of a different shape.

[0106] like Figure 3As shown, preferably, one hole 40 is formed with respect to one supply lumen 212 in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10. In addition, although not shown, a mode in which a plurality of holes 40 are formed with respect to one supply lumen 212 in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10 is also permitted.

[0107] like Figure 3 As shown, it is preferred that a plurality of holes 40 are formed, and in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10, only one hole 40 exists on a straight line passing through the centroid 210c of the first inner cylinder 210. Figure 3 In FIG. 1 , a straight line passing through the centroid 210c of the first inner tube 210 is indicated by a two-dot chain line. When the catheter 1 is bent, a force is particularly applied to a portion of the outer circumference of the first inner tube 210 that intersects with a straight line passing through the centroid 210c of the first inner tube 210. There are two portions of the outer circumference of the first inner tube 210 that intersect with a straight line passing through the centroid 210c of the first inner tube 210, but a force of extension in the longitudinal direction x of the outer tube 10 is applied to one of them, and a force of contraction in the longitudinal direction x of the outer tube 10 is applied to the other. In particular, the portion where the hole 40 is formed has lower rigidity than other portions and tends to be easily bent. In the cross section perpendicular to the longitudinal direction x of the outer tube 10, by configuring the structure so that only one hole 40 exists on a straight line passing through the centroid 210c of the first inner tube 210, it is easy to maintain the rigidity of the portion of the outer peripheral edge of the first inner tube 210 that intersects with the straight line passing through the centroid 210c of the first inner tube 210, and thus it is easy to improve the resistance to bending. As a result, it is easy to suppress the occlusion of the supply lumen 212 due to bending of the catheter 1.

[0108] like Figure 3 As shown, preferably, in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10, there is only one supply lumen 212 on a straight line passing through the centroid 210c of the first inner cylinder 210 and the hole 40. Figure 3In FIG. 1 , a straight line passing through the centroid 210c of the first inner tube 210 and the hole 40 is indicated by a two-dot chain line. When the catheter 1 is bent, a force is particularly applied to a portion on the outer periphery of the first inner tube 210 that intersects with a straight line passing through the centroid 210c of the first inner tube 210. There are two portions on the outer periphery of the first inner tube 210 that intersect with a straight line passing through the centroid 210c of the first inner tube 210, but a force of extension in the longitudinal direction x of the outer tube 10 is applied to one of them, and a force of contraction in the longitudinal direction x of the outer tube 10 is applied to the other. In particular, the portion where the hole 40 is formed has lower rigidity than other portions and tends to be easily bent. In the cross section perpendicular to the longitudinal direction x of the outer tube 10, by configuring the supply lumen 212 to exist only on a straight line passing through the centroid 210c of the first inner tube 210 and the hole 40, the rigidity of the portion of the outer peripheral edge of the first inner tube 210 intersecting with the straight line passing through the centroid 210c of the first inner tube 210 can be easily maintained, and the resistance to bending can be easily improved. As a result, occlusion of the supply lumen 212 due to bending of the catheter 1 can be easily suppressed.

[0109] like Fig.15 As shown, preferably, in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10, the plurality of supply cavities 212 are located on an imaginary circle 210s centered on the centroid 210c of the first inner cylinder 210. Fig.15 In FIG. 1 , a virtual circle 210s centered on the centroid 210c of the first inner cylinder 210 is indicated by a double-dashed line. Preferably, in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10, all of the plurality of supply cavities 212 formed in the first inner cylinder 210 are located on a virtual circle 210s centered on the centroid 210c of the first inner cylinder 210. The interior of the portion of the first inner cylinder 210 where the supply cavities 212 are formed is a hollow cavity, and thus the resistance to bending tends to be easily reduced. However, by forming the structure as described above, as shown in FIG. Fig.15 As shown in the figure, the supply lumens 212 are arranged along the circumferential direction of the first inner cylinder 210, so the portions where the resistance to bending is easily reduced are dispersed in the circumferential direction of the first inner cylinder 210. By doing so, the resistance to bending can be easily maintained regardless of the direction in which the first inner cylinder 210 bends. Although not shown in the figure, for the same reason as above, it is also preferred that the centroids 212c of the plurality of supply lumens 212 are all located on a virtual circle 210s centered on the centroid 210c of the first inner cylinder 210 in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10.

[0110] The fluid used in the conduit 1 may be a liquid or a gas. When the fluid is a liquid, liquid nitrogen or Freon may be used as the fluid. When the fluid is a gas, a gas may be used as the fluid. Examples of the gas include argon, carbon dioxide, and nitrous oxide. It is preferred that the fluid used in the conduit 1 is a gas.

[0111] like Fig.16 As shown, in a cross section perpendicular to the length direction x of the outer cylinder 10, the first inner cylinder 210 may also include: a first supply lumen 2121; a second supply lumen 2122 formed beside the first supply lumen 2121 in the circumferential direction of the first inner cylinder 210; and a third supply lumen 2123 formed beside the first supply lumen 2121 and the second supply lumen 2122 in the circumferential direction of the first inner cylinder 210. Although not shown, the first inner cylinder 210 may also include one or more supply lumens in addition to the first supply lumen 2121, the second supply lumen 2122, and the third supply lumen 2123, which can allow fluid to pass from the proximal side of the first inner cylinder 210 to the distal side. In this specification, any one of the first supply lumen 2121, the second supply lumen 2122, the third supply lumen 2123, and the fourth and subsequent supply lumens that can allow fluid to pass from the proximal side to the distal side of the inner tube 210, or any combination of two or more thereof, may be referred to as a supply lumen 212 or a plurality of supply lumens 212. As described above, by configuring the catheter 1 to have three or more supply lumens 212, even if two supply lumens 212 are blocked due to the bending of the catheter 1 when passing through a curved body cavity, fluid can be delivered through the remaining supply lumens 212. Thus, fluid can be stably delivered from the proximal side to the distal side.

[0112] like Fig.16 As shown, preferably, in a cross section perpendicular to the length direction x of the outer cylinder 10, the first inner cylinder 210 has: a first supply lumen 2121; and a second supply lumen 2122, which is formed beside the first supply lumen 2121 in the circumferential direction of the first inner cylinder 210, and in a cross section perpendicular to the length direction x of the outer cylinder 10, an angle α formed by a ray having the centroid 210c of the first inner cylinder 210 as one end and passing through the centroid 2121c of the first supply lumen 2121 and a ray having the centroid 210c of the first inner cylinder 210 as one end and passing through the centroid 2122c of the second supply lumen 2122 is greater than 105 degrees and less than 135 degrees. Fig.16 In FIG. 1 , a ray having the centroid 210c of the first inner cylinder 210 as one end and passing through the centroid 2121c of the first supply lumen 2121 and a ray having the centroid 210c of the first inner cylinder 210 as one end and passing through the centroid 2122c of the second supply lumen 2122 are represented by double-dashed lines.

[0113] The angle α is preferably 105 degrees or more, more preferably 110 degrees or more, and even more preferably 115 degrees or more. The angle α is preferably 135 degrees or less, more preferably 130 degrees or less, and even more preferably 125 degrees or less. The angle α is particularly preferably 120 degrees.

[0114] like Figure 3 As shown, it is preferred that the first discharge flow path 31 exists in a manner covering the entire outer surface 213 of the first inner cylinder 210 in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10. Although not shown, in a cross section perpendicular to the longitudinal direction x of the outer cylinder 10, the first discharge flow path 31 may exist in a manner covering only a portion of the outer surface 213 of the first inner cylinder 210.

[0115] like Figure 2 , Figure 4 , Figure 7 , Fig. 9 As shown, the catheter 1 preferably has a second inner cylinder 220, which extends along the length direction x of the outer cylinder 10 and is arranged in the inner cavity 15 of the outer cylinder 10 on the side closer to the first inner cylinder 210. The second inner cylinder 220 has: a 2-1 inner cylinder 221, which extends along the length direction x of the outer cylinder 10; and a 2-2 inner cylinder 222, which is arranged in the inner cavity 2213 of the 2-1 inner cylinder 221 and extends along the length direction x of the outer cylinder 10. There is a 2-1 flow path 2214 between the inner surface 2212 of the 2-1 inner cylinder 221 and the outer surface 2221 of the 2-2 inner cylinder 222, and the 2-1 flow path 2214 is connected to a plurality of supply lumens 212 formed in the first inner cylinder 210, and the inner cavity 2223 of the 2-2 inner cylinder 222 is connected to the guide wire lumen 211 formed in the first inner cylinder 210.

[0116] As a material constituting the second inner cylinder 220, the same synthetic resin, metal, etc. as the outer cylinder 10 can be used. The material constituting the second inner cylinder 220 may be the same as or different from the material constituting the outer cylinder 10. The material constituting the second inner cylinder 220 may be the same as or different from the material constituting the first inner cylinder 210.

[0117] The 2-1st inner cylinder 221 is in the shape of a cylinder, and can be in the shape of a hollow cylinder, a hollow polygonal column, etc. The 2-2nd inner cylinder 222 is in the shape of a cylinder, and can be in the shape of a hollow cylinder, a hollow polygonal column, etc.

[0118] like Figure 2 As shown, the 2-2 inner cylinder 222 may be entirely disposed in the inner cavity 2213 of the 2-1 inner cylinder 221. Figure 7As shown, a portion of the 2-2 inner cylinder 222 may be located in the inner cavity 2213 of the 2-1 inner cylinder 221, and another portion of the 2-2 inner cylinder 222 may be located radially outward of the 2-1 inner cylinder 221.

[0119] When the catheter 1 has a second inner tube 220, it is preferred that a second discharge flow path 32 is provided between the inner surface 14 of the outer tube 10 and the outer surface 2211 of the 2-1 inner tube 221, and the second discharge flow path 32 enables fluid to pass from the distal side of the outer tube 10 toward the proximal side, and the second discharge flow path 32 is preferably connected to the first discharge flow path 31.

[0120] like Figure 2 , Figure 5 As shown, the catheter 1 preferably has a third inner cylinder 230, which extends along the length direction x of the outer cylinder 10 and is arranged in the inner cavity 15 of the outer cylinder 10 closer to the second inner cylinder 220. In a cross-section perpendicular to the length direction x of the outer cylinder 10, the third inner cylinder 230 has: a 3-1 inner cavity 231, which extends along the length direction x of the outer cylinder 10 and is connected to the 2-1 flow path 2214; and a 3-2 inner cavity 232, which is formed in a region different from the 3-1 inner cavity 231 and is connected to the inner cavity 2223 of the 2-2 inner cylinder 222.

[0121] Preferably, in a cross section perpendicular to the longitudinal direction x of the outer tube 10, the centroid of the 3-1 lumen 231 does not overlap with the 3-2 lumen 232, and the centroid of the 3-2 lumen 232 does not overlap with the 3-1 lumen 231. Thus, the 3-2 lumen 232 can be easily formed near the outer edge of the third inner tube 230, and thus the opening 45 (guide wire port) described later can be easily formed in the catheter 1.

[0122] As the material constituting the third inner cylinder 230, the same synthetic resin, metal, etc. as that of the outer cylinder 10 can be used. The material constituting the third inner cylinder 230 may be the same as or different from the material constituting the outer cylinder 10. The material constituting the third inner cylinder 230 may be the same as or different from the material constituting the first inner cylinder 210. The material constituting the third inner cylinder 230 may be the same as or different from the material constituting the second inner cylinder 220.

[0123] Preferably, the catheter 1 has an opening 45, which connects the space radially outside the outer tube 10 with the 3-2 lumen 232 and allows the guide wire to be inserted. Figure 2As shown, preferably, at least a portion of the outer surface 233 of the third inner cylinder 230 is connected to the inner surface 14 of the outer cylinder 10, and the 3-2 inner cavity 232 is close to the outer cylinder 10 toward the connecting portion, and an opening 45 is provided in a manner that the 3-2 inner cavity 232 is connected to the space radially outside the outer cylinder 10. Figure 2 The opening 45 of the catheter 1 shown is a so-called guidewire port.

[0124] When the catheter 1 has a third inner tube 230, it is preferred that a third discharge flow path 33 is provided between the inner surface 14 of the outer tube 10 and the outer surface 233 of the third inner tube 230, and the third discharge flow path 33 can allow fluid to pass from the distal side of the outer tube 10 toward the proximal side. Preferably, the third discharge flow path 33 is connected to the first discharge flow path 31 and the second discharge flow path 32.

[0125] like Figure 2 , Figure 6 As shown, the catheter 1 preferably has a fourth inner tube 240, which extends along the length direction x of the outer tube 10 and is arranged in the inner cavity 15 of the outer tube 10 closer to the third inner tube 230, and the inner cavity 243 of the fourth inner tube 240 is connected to the 3-1 inner cavity 231.

[0126] The fourth inner tube 240 is in a cylindrical shape, and may be in a hollow cylindrical shape, a hollow polygonal column shape, or the like.

[0127] As the material constituting the fourth inner cylinder 240, the same synthetic resin, metal, etc. as that of the outer cylinder 10 can be used. The material constituting the fourth inner cylinder 240 may be the same as or different from the material constituting the outer cylinder 10. The material constituting the fourth inner cylinder 240 may be the same as or different from the material constituting the first inner cylinder 210. The material constituting the fourth inner cylinder 240 may be the same as or different from the material constituting the second inner cylinder 220. The material constituting the fourth inner cylinder 240 may be the same as or different from the material constituting the third inner cylinder 230.

[0128] When the catheter 1 has a fourth inner tube 240, it is preferred that a fourth discharge flow path 34 is provided between the inner surface 14 of the outer tube 10 and the outer surface 241 of the fourth inner tube 240. The fourth discharge flow path 34 enables fluid to pass from the distal side of the outer tube 10 toward the proximal side. The fourth discharge flow path 34 is preferably connected to the first discharge flow path 31, the second discharge flow path 32, and the third discharge flow path 33.

[0129] In addition, as another embodiment, Figure 7 , Fig.10As shown, the catheter 1 preferably has a fifth inner cylinder 250 extending in the length direction x and arranged in the inner cavity 15 of the outer cylinder 10 closer to the second inner cylinder 220 , and the inner cavity 253 of the fifth inner cylinder 250 is connected to the 2-1 flow path 2214 .

[0130] like Figure 7 to Figure 10 As shown, when the catheter 1 has the first inner tube 210, the second inner tube 220 and the fifth inner tube 250, it is preferable not to provide the third inner tube 230 described above.

[0131] like Figure 7 As shown, the catheter 1 preferably has an opening 45, which connects the space radially outside the outer tube 10 with the inner cavity 2223 of the 2-2 inner tube 222 and allows the guide wire to be inserted. Figure 7 As shown, the opening 45 can be provided by configuring the distal portion of the 2-2 inner tube 222 to penetrate the side wall of the 2-1 inner tube 221 and the side wall of the outer tube 10. Figure 7 The opening 45 of the catheter 1 shown is a so-called guidewire port.

[0132] The fifth inner tube 250 is in a cylindrical shape, and may be in a hollow cylindrical shape, a hollow polygonal column shape, or the like.

[0133] As the material constituting the fifth inner cylinder 250, the same synthetic resin, metal, etc. as that of the outer cylinder 10 can be used. The material constituting the fifth inner cylinder 250 may be the same as or different from the material constituting the outer cylinder 10. The material constituting the fifth inner cylinder 250 may be the same as or different from the material constituting the first inner cylinder 210. The material constituting the fifth inner cylinder 250 may be the same as or different from the material constituting the second inner cylinder 220.

[0134] When the catheter 1 has a fifth inner tube 250, it is preferred that a fifth discharge flow path 35 is provided between the inner surface 14 of the outer tube 10 and the outer surface 251 of the fifth inner tube 250, and the fifth discharge flow path 35 is capable of allowing fluid to pass from the distal side of the outer tube 10 toward the proximal side. The fifth discharge flow path 35 is preferably connected to the first discharge flow path 31 and the second discharge flow path 32.

[0135] like Figure 1 , Figure 2 , Figure 7 , Fig.11 , Fig.12 As shown, the catheter 1 may further include a front tip 60, and the front tip 60 is formed with an inner cavity 63 extending along the length direction x. Figure 1 , Figure 2 , Figure 7 As shown, it is preferred that the distal end portion of the outer tube 10 and the distal end portion of the first inner tube 210 are fixed to the proximal end portion of the distal tip 60 .

[0136] Preferably, the distal end of the outer tube 10 and the distal end of the first inner tube 210 are fixed, so that the first discharge flow path 31 of the catheter 1 is blocked at the distal side. Figure 1 , Figure 2 As shown, the distal end of the outer tube 10 and the distal end of the first inner tube 210 can be fixed via the front tip 60, so that the distal side of the first discharge flow path 31 in the length direction x of the outer tube 10 is blocked. Although not shown, the distal end of the outer tube 10 and the distal end of the first inner tube 210 can be welded and fixed in a manner that blocks the distal side of the first discharge flow path 31 without providing the front tip 60. Fig.11 , Fig.12 As shown, when the outer tube 10 has a balloon 50, the distal end of the balloon 50 and the distal end of the first inner tube 210 can be fixed to block the first discharge flow path 31 of the catheter 1 at the distal side. As a result, the main direction of movement of the fluid ejected from the hole 40 to the radially outer side of the outer tube 10 can be toward the proximal side of the first discharge flow path 31.

[0137] like Figure 1 , Figure 2 , Figure 7 , Fig.11 , Fig.12 As shown, the catheter 1 preferably further includes a front tip 60, which is formed with an inner cavity 63 extending along the length direction x of the outer tube 10, and the outer diameter decreases from the proximal side to the distal side, and the distal end of the outer tube 10 and the distal end of the first inner tube 210 are fixed to the proximal end of the front tip 60. By having the front tip 60 with an outer diameter that decreases from the proximal side to the distal side, the distal end of the catheter 1 can be easily inserted into the body cavity.

[0138] The shape of the front tip 60 can be, for example, a hollow cylindrical shape, a hollow polygonal column shape, a hollow truncated cone shape, etc. Figure 1 , Figure 2 As shown, it is preferably in the shape of a hollow truncated cone.

[0139] As a material constituting the distal tip 60, synthetic resin, metal, etc. similar to those of the outer tube 10 can be used. The material constituting the distal tip 60 and the material constituting the outer tube 10 may be the same or different.

[0140] like Figure 1 , Figure 2 , Figure 7 , Fig.11 , Fig.12 As shown in FIG. 1 , a first handle 75 for the user to hold can be connected to the proximal portion of the outer tube 10. Figure 2 , Figure 7 , Fig.12In the embodiment, the first handle 75 has a hollow portion extending along the length direction x of the outer tube 10. The shape of the first handle 75 may be, for example, a cylindrical shape. Fig.12 In the embodiment, the outer tube 10 and the first inner tube 210 are inserted into the hollow portion of the first handle 75. Figure 2 In the embodiment, the outer tube 10 and the fourth inner tube 240 are inserted into the hollow portion of the first handle 75. Figure 7 In the embodiment, the outer tube 10 and the fifth inner tube 250 are inserted into the hollow portion of the first handle 75 .

[0141] like Fig.11 , Fig.12 As shown in FIG. 2 , the second handle 76 can be connected to the proximal portion of the first inner tube 210. Fig.12 In the embodiment, the second handle 76 has a hollow portion extending along the length direction x of the outer tube 10. The shape of the second handle 76 may be, for example, a cylindrical shape. Fig.12 In the embodiment, the first inner tube 210 is inserted into the hollow portion of the second handle 76. The second handle 76 may also have an opening for inserting a guide wire, namely, a guide wire port. In addition, the second handle 76 may be connected to the fluid supply device 80 described later. Fig.12 As shown, the proximal end of the first inner tube 210 and the fluid supply device 80 may be directly connected in a manner that fluid can be supplied to the supply lumen 212 of the first inner tube 210 .

[0142] The material constituting the first handle 75 and the second handle 76 is not particularly limited, and for example, polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), polycarbonate resins, ABS resins, and synthetic resins such as polyurethane resins can be used.

[0143] It is preferable to apply the coating to the outer surface 13 of the outer cylinder 10. The coating may be applied to only a part of the outer surface 13 of the outer cylinder 10 or to the entire outer surface 13 of the outer cylinder 10.

[0144] The coating applied to the outer surface 13 of the outer cylinder 10 may be a hydrophilic coating or a hydrophobic coating, which can be selected according to the purpose. The coating can be applied to the outer surface 13 of the outer cylinder 10 by immersing the outer cylinder 10 in a hydrophilic coating agent or a hydrophobic coating agent, or by coating the outer surface 13 of the outer cylinder 10 with a hydrophilic coating agent or a hydrophobic coating agent, or by coating the outer surface 13 of the outer cylinder 10 with a hydrophilic coating agent or a hydrophobic coating agent. The coating agent may also contain a drug or an additive.

[0145] Examples of the hydrophilic coating agent include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinyl pyrrolidone, and methyl vinyl ether maleic anhydride copolymer, and hydrophilic coating agents prepared by any combination thereof.

[0146] Examples of hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic polyurethane resin, carbon coating, diamond coating, diamond-like carbon (DLC) coating, ceramic coating, and substances with low surface free energy terminated with alkyl or perfluoroalkyl groups.

[0147] The above-mentioned coating may be applied to the outer surface 61 of the distal tip 60. The coating may be applied to only a part of the outer surface 61 of the distal tip 60 or to the entire outer surface 61 of the distal tip 60.

[0148] A cryoablation catheter system according to an embodiment of the present invention is a cryoablation catheter system including the catheter 1 described above and a fluid supply device 80 for supplying fluid to the supply lumen 212 , and the gist of the system is that the first inner tube 210 is connected to the fluid supply device 80 .

[0149] The fluid supply device 80 is not particularly limited as long as it can supply the fluid to the first inner tube 210. Examples of the fluid supply device 80 include a regulator connected to a fluid storage container, a flow controller, and a pump.

[0150] The first inner cylinder 210 can be directly connected to the fluid supply device 80. Fig.12 , Fig.13 , Fig.14 In the case of the catheter 1 as shown, the three supply lumens 212 may merge into one on the proximal side, and the proximal end of the first inner tube 210 may be directly connected to the fluid supply device 80 .

[0151] The first inner cylinder 210 may also be indirectly connected to the fluid supply device 80. For example, Figure 2 As shown, the second inner cylinder 220, the third inner cylinder 230 and the fourth inner cylinder 240 may be present between the first inner cylinder 210 and the fluid supply device 80, and the first inner cylinder 210 and the fluid supply device 80 may be indirectly connected via the second inner cylinder 220, the third inner cylinder 230 and the fourth inner cylinder 240. Figure 7 As shown, the second inner cylinder 220 and the fifth inner cylinder 250 may be present between the first inner cylinder 210 and the fluid supply device 80 , and the first inner cylinder 210 and the fluid supply device 80 may be indirectly connected via the second inner cylinder 220 and the fifth inner cylinder 250 .

[0152] This application claims the benefit of priority based on Japanese Patent Application No. 2022-176154 filed on November 2, 2022. The entire contents of the specification of Japanese Patent Application No. 2022-176154 filed on November 2, 2022 are incorporated herein by reference.

[0153] Description of Reference Numerals

[0154] 1…cryoablation catheter; 10…outer tube; 11…distal end of outer tube; 12: proximal end of outer tube; 13…outer surface of outer tube; 14…inner surface of outer tube; 15…inner cavity of outer tube; 16…cylindrical member; 210…first inner tube; 210c…centroid of first inner tube; 210s…imaginary circle centered on centroid of first inner tube; 211…guidewire cavity; 211c…centroid of guidewire cavity; 212…supply cavity; 212c…centroid of supply cavity; 2121…first supply cavity; 2121c…centroid of first supply cavity centroid; 2122…second supply lumen; 2122c…centroid of second supply lumen; 2123…third supply lumen; 2123c…centroid of third supply lumen; 213…outer surface of first inner cylinder; 214…inner surface of first inner cylinder; 220…second inner cylinder; 221…2-1 inner cylinder; 2211…outer surface of 2-1 inner cylinder; 2212…inner surface of 2-1 inner cylinder; 2213…inner lumen of 2-1 inner cylinder; 2214…2-1 flow path; 222…2-2 inner cylinder; 2221…2-2 The outer surface of the inner cylinder; 2222… The inner surface of the 2nd inner cylinder; 2223… The inner cavity of the 2nd inner cylinder; 230… The 3rd inner cylinder; 231… The inner cavity of the 3rd-1st inner cylinder; 232… The inner cavity of the 3rd-2nd inner cylinder; 233… The outer surface of the 3rd inner cylinder; 240… The 4th inner cylinder; 241… The outer surface of the 4th inner cylinder; 242… The inner surface of the 4th inner cylinder; 243… The inner cavity of the 4th inner cylinder; 250… The 5th inner cylinder; 251… The outer surface of the 5th inner cylinder; 252… The inner surface of the 5th inner cylinder; 253… The inner cavity of the 5th inner cylinder; 31… The 1st discharge flow channel; 32…the second discharge channel; 33…the third discharge channel; 34…the fourth discharge channel; 35…the fifth discharge channel; 40…the hole; 45…the opening; 50…the balloon; 51…the straight tube portion; 52…the distal tapered portion; 53…the proximal tapered portion; 54…the distal sleeve portion; 55…the proximal sleeve portion; 60…the front end tip; 61…the outer surface of the front end tip; 62…the inner surface of the front end tip; 63…the inner cavity of the front end tip; 70…the X-ray opaque marker; 75…the first handle; 76…the second handle; 80…the fluid supply device.

Claims

1. A cryoablation catheter for insertion into the duodenal papilla, comprising: An outer cylinder having a distal end and a proximal end and extending in a length direction; and a first inner tube extending along the length direction and arranged in the inner cavity of the outer tube, The cryoablation catheter is characterized in that: In a cross section perpendicular to the longitudinal direction, the first inner tube has: a guidewire lumen for inserting a guidewire; and a plurality of supply lumens formed in a region different from the guidewire lumen and capable of allowing fluid to pass from the proximal side of the first inner tube toward the distal side. The cryoablation catheter has a first discharge flow path between the inner surface of the outer tube and the outer surface of the first inner tube, and the first discharge flow path allows the fluid to pass from the distal side of the outer tube to the proximal side. A hole that connects the supply lumen and the first discharge flow path is formed in the distal portion of the first inner tube.

2. The cryoablation catheter according to claim 1, It is characterized in that In a cross section perpendicular to the longitudinal direction, an eccentric distance of the centroid of the supply lumen relative to the centroid of the first inner tube is greater than an eccentric distance of the centroid of the guidewire lumen relative to the centroid of the first inner tube.

3. The cryoablation catheter according to claim 1 or 2, It is characterized in that In a cross section perpendicular to the longitudinal direction, the guide wire lumen is formed at a position overlapping with the centroid of the first inner tube, and the supply lumen is formed at a position not overlapping with the centroid of the first inner tube.

4. The cryoablation catheter according to claim 1 or 2, It is characterized in that The first inner cylinder is integrally formed of a predetermined material.

5. The cryoablation catheter according to claim 1 or 2, It is characterized in that The holes are formed in a plurality of In a cross section perpendicular to the longitudinal direction, there is only one hole on a straight line passing through the centroid of the first inner cylinder.

6. The cryoablation catheter according to claim 1 or 2, It is characterized in that In a cross section perpendicular to the longitudinal direction, there is only one supply lumen on a straight line passing through the centroid of the first inner cylinder and the hole.

7. The cryoablation catheter according to claim 1 or 2, It is characterized in that In a cross section perpendicular to the longitudinal direction, the plurality of supply lumens are located on an imaginary circle centered at the centroid of the first inner cylinder.

8. The cryoablation catheter according to claim 1 or 2, It is characterized in that The outer tube has a balloon at a distal portion of the outer tube that is expandable and contractible in a radial direction of the outer tube.

9. The cryoablation catheter according to claim 8, It is characterized in that The thermal conductivity of the material constituting the balloon is higher than the thermal conductivity of the material constituting the portion of the outer tube other than the balloon.

10. The cryoablation catheter according to claim 1 or 2, It is characterized in that The fluid is a gas.

11. The cryoablation catheter according to claim 1 or 2, It is characterized in that In a cross section perpendicular to the longitudinal direction, the first inner tube has: a first supply lumen; and a second supply lumen formed beside the first supply lumen in the circumferential direction of the first inner tube, In a cross section perpendicular to the longitudinal direction, an angle α formed by a ray passing through the centroid of the first supply lumen with the centroid of the first inner cylinder as one end and a ray passing through the centroid of the second supply lumen with the centroid of the first inner cylinder as one end is greater than 105 degrees and less than 135 degrees.

12. The cryoablation catheter according to claim 1 or 2, It is characterized in that The cryoablation catheter has a second inner tube extending along the longitudinal direction and arranged in the inner cavity of the outer tube at a position closer to the first inner tube. The second inner cylinder comprises: a 2-1 inner cylinder extending along the length direction; and a 2-2 inner cylinder disposed in the inner cavity of the 2-1 inner cylinder and extending along the length direction. There is a 2-1 flow path between the inner surface of the 2-1 inner tube and the outer surface of the 2-2 inner tube, and the 2-1 flow path is connected to a plurality of supply cavities formed in the 1st inner tube. The inner cavity of the 2-2 inner tube is communicated with the guide wire inner cavity formed in the first inner tube.

13. The cryoablation catheter according to claim 12, It is characterized in that The cryoablation catheter has a third inner tube extending along the longitudinal direction and arranged in the inner cavity of the outer tube at a position closer to the second inner tube. In a cross section perpendicular to the longitudinal direction, the 3rd inner tube comprises: a 3-1 inner cavity extending along the longitudinal direction and connected to the 2-1 flow path; and a 3-2 inner cavity formed in a region different from the 3-1 inner cavity and connected to the inner cavity of the 2-2 inner tube.

14. The cryoablation catheter according to claim 13, It is characterized in that The cryoablation catheter has a fourth inner tube extending along the longitudinal direction and arranged in the inner cavity of the outer tube at a position closer to the third inner tube. The inner cavity of the 4th inner cylinder is communicated with the 3-1 inner cavity.

15. The cryoablation catheter according to claim 1 or 2, It is characterized in that The cryoablation catheter further comprises a front end tip, the front end tip is formed with an inner cavity extending along the length direction, and the outer diameter decreases from the proximal side to the distal side. The distal end portion of the outer tube and the distal end portion of the first inner tube are fixed to the proximal end portion of the front end tip.

16. A cryoablation catheter system, comprising: the cryoablation catheter according to claim 1 or 2; and a fluid supply device for supplying the fluid to the supply lumen, The cryoablation catheter system is characterized in that: The first inner cylinder is connected to the fluid supply device.

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