JP7306376B2 - Balloon catheter for stone removal - Google Patents

Description

TECHNICAL FIELD The present invention relates to a calculus removal balloon catheter used for removing calculus formed in a body lumen such as a bile duct.

A stone removal balloon catheter for removing gallstones (calculus) formed in the bile duct is known (see, for example, Patent Document 1). When removing gallstones from the bile duct, first, an endoscope is orally inserted to the vicinity of the duodenal papilla, and a deflated balloon catheter is inserted into the bile duct through the instrument guide tube of the endoscope. The balloon is inserted and positioned behind the position of the gallstone to be removed while observing the X-ray fluoroscopic image. Then, after the balloon is inflated, the balloon catheter is pulled back, so that the gallstone can be excreted out of the bile duct by scraping out the gallstone with the balloon.

As a catheter tube used for such a balloon catheter for calculus removal, a catheter tube having a single tube structure having a guide wire lumen for inserting a guide wire and a balloon lumen for supplying fluid to the balloon is used. The distal end portion is heat-compressed using a mold to close the balloon lumen and to have a tapered tip shape. Here, the catheter tube should be flexible enough to follow the curvature of the endoscope, and rigid enough to allow the catheter tube to advance without bending inside the treatment instrument guide tube or the lumen of the body. It is requested to prepare for both.

By the way, in recent years, the development of small-diameter endoscopes represented by transnasal endoscopes has progressed. is inserted into the bile duct through the duodenal papilla, and the inside of the bile duct can be directly observed using the camera provided with the endoscope. In such a small-diameter endoscope, since the inner diameter of the treatment instrument guide tube is also small, it is necessary to correspondingly reduce the diameter of the calculus removal balloon catheter inserted therethrough. In addition, since narrow-diameter endoscopes tend to have a larger curvature than general oral endoscopes, the catheter tube is required to have a higher degree of flexibility.

However, it is difficult to achieve both flexibility and rigidity with a conventional single-tube catheter tube. If the flexibility is increased to sufficiently follow the curvature of the scope, there is a problem that the necessary rigidity cannot be secured. In addition, since the tip (distal end) of the catheter tube hardens with respect to the rest of the catheter tube due to heat compression, it can be inserted into the instrument guide tube of a small-diameter endoscope, which may have a relatively large curvature. may interfere with insertion.

JP 2012-143377 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a calculus removal balloon catheter that can be suitably used for an endoscope having a treatment instrument guide tube with a small inner diameter.

In order to achieve the above object, the balloon catheter for calculus removal according to the present invention comprises:
a catheter tube having a double-tube structure, which includes an outer tube having supply and discharge holes penetrating inside and outside in the vicinity of the distal end thereof, and an inner tube inserted into the outer tube with a gap;
A supply/discharge path and the supply/discharge hole are provided on the outer periphery near the distal end of the outer tube so as to surround the supply/discharge hole, and are defined between the inner surface of the outer tube and the outer surface of the inner tube. a balloon that is inflated or deflated by supplying and discharging fluid to the inside through the balloon;
an inner tube mounting hole provided with an inner tube abutting surface against which the distal end surface of the inner tube abuts when the distal end portion of the inner tube is inserted; and an inner tube mounted in the inner tube mounting hole. It has a lumen that continues to the cavity and opens to the distal end, and a substantially cylindrical distal tip that has an outer tube contacting surface against which the distal end surface of the outer tube contacts.

The calculus removal balloon catheter according to the present invention uses a double-tube structure in which the inner tube is inserted through the outer tube as the catheter tube. The other can be made of a material that emphasizes rigidity. Therefore, even when the diameter of the catheter tube is reduced, both necessary rigidity and flexibility can be achieved. In addition, since it has a tip separate from the catheter tube, the distal end (tip) can be softened compared to the conventional case where the tip shape is given by heat compression, Even when the instrument is inserted into a treatment instrument guide tube of a small-diameter endoscope that may have a relatively large curvature, it is possible to reduce interference with insertion.

In the calculus removal balloon catheter according to the present invention, the inner tube may be made of a harder material than the outer tube. By making the inner tube rigid, it is possible to reduce the deformation of the lumen of the inner tube as it bends, and when inserting a guide wire into the lumen of the inner tube, it does not interfere with the insertion of the guide wire. can be suppressed.

In the calculus removal balloon catheter according to the present invention, the outer tube may have an outer diameter within a range of 0.6 to 2.5 mm. The present invention is particularly effective when applied to such a small-diameter balloon catheter.

FIG. 1 is an overall view showing an outline of a calculus removing balloon catheter according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II of FIG. FIG. 3 is an enlarged cross-sectional view of the vicinity of the distal end portion of the calculus removal balloon catheter of FIG. 1 cut along a plane including the axis. 4 is a cross-sectional view showing the configuration of the distal tip of the calculus removing balloon catheter of FIG. 1. FIG. 5 is a cross-sectional view showing another configuration of the distal tip of the calculus removing balloon catheter of FIG. 1. FIG. 6 is a cross-sectional view showing still another configuration of the distal tip of the calculus removing balloon catheter of FIG. 1. FIG. FIG. 7 is an overall view showing an outline of a calculus removing balloon catheter according to another embodiment of the present invention. 8 is an enlarged cross-sectional view of the vicinity of the distal end portion of the calculus removal balloon catheter of FIG. 7 taken along a plane including the axis.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. The calculus removal balloon catheter of the present embodiment is an endoscope that is inserted into a body lumen via a treatment instrument guide tube of an endoscope and is used to scrape out calculus or the like generated in the body lumen. It is a treatment tool. In the following description, the stone removal balloon catheter of the present embodiment is inserted into the patient's body through a small-diameter endoscope sold as a transnasal endoscope to remove gallstones and the like in the bile duct. A case will be described as an example.

Here, as a specific example of a small-diameter endoscope suitable for inserting the calculus-removing balloon catheter of the present embodiment, a small-diameter endoscope sold as a transnasal endoscope can be mentioned. be able to. The outer diameter (shaft diameter) of general oral endoscopes is 10 to 14 mm, while the outer diameter (shaft diameter) of small-diameter endoscopes sold as transnasal endoscopes (shaft diameter) is 10 to 14 mm. diameter) is 4.9 to 5.9 mm. In addition, while the inner diameter (channel diameter) of the treatment instrument guide tube of a general oral endoscope is usually about 3.7 mm, the small-diameter endoscope sold as a transnasal endoscope The inner diameter (channel diameter) of the treatment instrument guide tube is about 2.0 to 2.5 mm.

The calculus removal balloon catheter of the present embodiment is optimized so that it can be used by inserting it into a treatment instrument guide tube of a small-diameter endoscope, such as one sold as a transnasal endoscope. Needless to say, it can be used by inserting it into a treatment instrument guide tube of an oral endoscope.

First, refer to FIGS. 1 to 3. FIG. A balloon catheter 1 of this embodiment roughly includes a catheter tube 2, a balloon 3, a distal tip 4, a cover 5, two branch tubes (branch tubes) 6a and 7a, and two ports 6b and 7b. configured as follows.

The catheter tube 2 has a distal end to be inserted into the body and a proximal end to be placed outside the body, and is inserted into an outer tube (outer tube) 21 and the lumen of the outer tube 21 with a gap. It is a long member with a double-tube structure having an inner tube (inner tube) 22 that is attached to the inner tube.

The outer diameter of the outer tube 21 can be set within the range of 0.6 to 2.5 mm, preferably within the range of 1.0 to 2.5 mm. The inner diameter of the outer tube 21 can be set within the range of 0.5 to 2.0 mm.

The outer diameter of the inner tube 22 is in the range of 0.4 to 1.8 mm so that there is a gap between the inner surface of the outer tube 21 and the inner surface of the outer tube 21 to form an air supply/exhaust path (air supply/exhaust path) 21a, which will be described later. is set within The inner diameter of the inner tube 22 is set to a value that allows the guide wire to be slidably inserted. It is set within the range of 0.64 to 1.00 mm.

The total length of the catheter tube 2 (outer tube 21, inner tube 22) is approximately 500 to 3000 mm.

As the material of the outer tube 21, it is preferable to use a polymer material that is flexible and softer than the inner tube 22, such as polyether block amide copolymer, polyethylene, polyethylene terephthalate, and polypropylene. , ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride (PVC), crosslinked ethylene-vinyl acetate copolymer, polyurethane, polyamide, polyamide elastomer, polyimide, polyimide elastomer, silicone rubber, etc. be able to. As the material of the inner tube 22, it is preferable to use a material having flexibility and a polymer material harder than the outer tube 21, such as polyetheretherketone, polysulfone, polyethersulfone, and polyetherimide. etc. can be used.

The space defined between the inner surface of the outer tube 21 and the outer surface of the inner tube 22 supplies the inside of the balloon 3 with a fluid (air in this embodiment) used to inflate or deflate the balloon 3. It is also used as an air supply/exhaust passage 21a, which is a passage for discharging from the inside of the balloon 3. As shown in FIG. For this reason, an air supply/exhaust hole ( A supply/discharge hole) 21b is formed.

The lumen 22a of the inner tube 22 is used for inserting a guide wire and, if necessary, as a flow path for a contrast agent when performing X-ray imaging in the bile duct, or for physiological saline or the like in the bile duct. It is used as a flow path for supplying

The balloon 3 expands when air is supplied (injected) into its interior, and conversely contracts when air is discharged (sucked). It is attached so as to surround and cover the hole 21b. In this embodiment, the balloon 3 is a body-of-rotation balloon whose rotation axis is the axis of the catheter tube 2 (a non-eccentric balloon that is not eccentric with respect to the axis of the catheter tube 2). Gallstones in the bile duct can be removed by scraping out or pushing out the gallstones by the inflated balloon 3 .

The elastic material forming the balloon 3 preferably has a 100% modulus (value measured according to JIS K 6251) of 0.1 to 10 Mpa, particularly preferably 1 to 5 Mpa. If the 100% modulus is too small, the strength of the balloon 3 may be insufficient, and if it is too large, the balloon 3 may not be inflated to a sufficient size. Specific examples of stretchable materials suitable for forming the balloon 3 include natural rubber, silicone rubber, polyurethane elastomer, and the like.

In this embodiment, the balloon 3 is in a deflated state and has a cylindrical shape as a whole, and substantially cylindrical joints 3a and 3b are formed at both ends of the balloon 3 to be joined to the outer peripheral surface of the catheter tube 2. An inflatable portion 3c is formed between the joint portions 3a and 3b, and is inflated by being supplied with fluid. The inflatable portion 3c of the balloon 3 is in a state where no external force is applied (a state in which no fluid is supplied to the interior and the balloon 3 is contracted due to the internal pressure being in balance with the external pressure). As a rotating shaft, it is formed in a shape of a body of revolution formed by rotating a curved line convex toward the outside of the catheter tube 2 . The method of joining the joints 3a and 3b of the balloon 3 and the catheter tube 2 is not particularly limited, and examples thereof include adhesion with an adhesive, heat fusion, solvent fusion, ultrasonic fusion, and high frequency fusion. can be mentioned.

The inflatable portion 3c of the balloon 3 has a maximum outer diameter equal to that of the joint portion 3b in a state in which no external force is applied (a state in which no fluid is supplied to the interior and the balloon 3 is contracted due to the internal pressure being in balance with the external pressure). It is preferably 110-200% of the outer diameter. If this ratio is too small, the balloon 3 may not expand to a sufficient size. . In addition, the outer diameter of the balloon 3 (inflatable portion 3c) when inflated may vary depending on the pressure of the fluid supplied to the inside, but it should be possible to inflate the outer diameter to at least 10 mm or more in order to scrape out gallstones in the bile duct. Preferably, it is more preferably expandable to an outer diameter of at least 15 mm or more. In addition, the length of the expansion portion 3c of the balloon 3 (the length along the axial direction of the catheter tube 2) is preferably 2 to 20 mm, more preferably 3 to 20 mm, and the thickness is 0.10 to 0.50 mm. is preferably The thickness of the balloon 3 is preferably uniform along the circumferential direction.

The method for manufacturing the balloon 3 is not particularly limited, and a known method for forming a film of a stretchable material may be used, but it is preferable to use a dipping molding method or a melt molding method, and it is particularly preferable to use a dipping molding method. preferable. In the dipping molding method, an elastic material and, if necessary, various additives are dissolved in a solvent to form a solution or suspension. The solution (suspension) is applied to the surface of the mold by immersion, and the solvent is evaporated to form a coating on the surface of the mold. By repeating this immersion and drying, a balloon having a desired thickness can be formed. Depending on the type of stretchable material, cross-linking may be performed after forming the film, if necessary.

A distal tip 4 is attached to the distal end of the catheter tube 2, and the distal tip 4, as shown in FIG. It is a substantially cylindrical member having a tube mounting portion 43 .

The shape of the outer periphery of the distal tip 4 is a straight body shape (straight body portion 4a) whose diameter does not substantially change on the base end (proximal end) side in the axial direction, and is tapered on the tip (distal end) side. It has a tapered shape (tapered portion 4b). The shape of the outer periphery of the distal tip 4 is not limited to this, and may be a single tapered tapered shape extending in the axial direction, or a combination of multiple tapered tapered shapes having different inclination angles. A single or a plurality of narrow tapered shapes and a single or a plurality of wide tapered shapes and/or straight body shapes may be mixed. The tip (distal end) of the distal tip 4 is preferably chamfered so as to have a smooth shape so that it does not get caught on the treatment instrument guide tube or the inner wall of the body lumen and interfere with insertion.

The lumen 41 of the distal tip 4 has a distal end opening 41a that opens at the distal end thereof, and the proximal end thereof is formed so as to be continuous with the lumen 22a of the inner tube 22 mounted in the inner tube mounting hole 42. . The inner diameter of the lumen 41 is set to substantially the same value as the inner diameter of the inner tube 22 .

The inner tube mounting hole 42 is a portion to which the distal end portion of the inner tube 22 is mounted, and is a substantially cylindrical hole formed substantially coaxially with the inner tube 41 on the proximal end side of the inner tube 22 . is a hole. The inner diameter of the inner tube mounting hole 42 is set to substantially the same value as the outer diameter of the inner tube 22 . The inner tube mounting hole 42 has an inner tube contact surface (inner tube contact surface) 42a against which the distal end face of the inner tube 22 contacts when the distal end portion of the inner tube 22 is inserted.

Adhesive is applied to one or both of the inner peripheral surface of the inner tube mounting hole 42 and the outer peripheral surface of the distal end portion of the inner tube 22, and the distal end portion of the inner tube 22 is inserted or press-fitted into the inner tube mounting hole 42. As a result, the distal end portion of the inner tube 22 is adhesively fixed to the distal tip 4 while the lumen 22 a of the inner tube 22 is connected to the lumen 41 of the distal tip 4 .

The outer tube mounting portion 43 is a portion to which the distal end portion of the outer tube 21 is mounted, and includes an outer tube contact surface (outer tube contact surface) 43a with which the distal end surface of the outer tube 21 contacts. . In this embodiment, the base end surface (proximal end surface) of the distal tip 4 is the outer tube contact surface 43a. Adhesive is applied to one or both of the outer tube contact surface 43a and the distal end surface of the outer tube 21, and the distal end portion of the outer tube 21 is brought into contact or pressure contact with the outer tube contact surface 43a. The distal end of the outer tube 21 is adhesively fixed to the tip 4 while the distal end of the exhaust path 21 a is hermetically sealed (closed) by the tip 4 .

As the adhesive used to adhere and fix the inner tube 22 and the outer tube 21 to the distal tip 4, a cyanoacrylate adhesive, an epoxy resin adhesive, a silicone rubber adhesive, or the like can be used. The fixing of the inner tube 22 and the outer tube 21 to the distal tip 4 may be performed by thermal welding, solvent welding, ultrasonic welding, or the like.

In FIG. 1, branch tubes 6a and 7a are connected to the proximal end side of the catheter tube 2 at the cover 5 portion. The branch tube 6a is a tube whose distal end is connected to the proximal end of the lumen 22a of the inner tube 22, and the branch tube 7a is a tube whose distal end is connected to the lumen of the outer tube 21. It is the tube connected to the proximal end of the supply/exhaust channel 21 a ) defined by the inner surface and the outer surface of the inner tube 22 . Although the material of the branch pipes 6a and 7a is not particularly limited, it is preferable to use a polymer material.

A port 6b is connected to the proximal end of the branch tube 6a, and a port 7b is connected to the proximal end of the branch tube 7a. A syringe or the like is connected to the port 6b so that a contrast medium, a drug solution, or the like can be fed into the lumen 22a of the inner tube 22. As shown in FIG. A guide wire can also be inserted through the opening of the port 6b and passed through the lumen 22a of the inner tube 22. As shown in FIG. A syringe or the like is connected to the port 7b so that a fluid (in this embodiment, air) for inflating the balloon 3 can be fed into the supply/exhaust path 21a.

Although the material of the ports 6b and 7b is not particularly limited, it is preferable to use a transparent polymeric material. The connection method between the branch tube 6a and the lumen 22a of the inner tube 22 and between the branch tube 7a and the air supply/exhaust passage 21a is not particularly limited. is airtightly penetrated and led to the outside, the distal ends of the branch tubes 6a and 7a are tapered, an adhesive is applied to the outer peripheral surface, and the ends are attached to the corresponding tubes of the catheter tube 2 By inserting them into 21 and 22, they can be adhered.

Connections between the catheter tube 2 and the branch tubes 6a and 7a are reinforced and protected by a cover 5. As shown in FIG. The cover 5 is provided so as to cover the connections between the catheter tube 2 and the branch tubes 6a and 7a. Although the shape of the cover 5 is not particularly limited, it is usually box-shaped or cylindrical. Although the material of the cover 5 is not particularly limited, it is preferable to use a polymer material. A heat-shrinkable tube can also be used as the cover 5 .

When removing gallstones in the bile duct using the balloon catheter 1 described above, first, an endoscope is inserted into the patient's body, and the distal end of the endoscope is inserted into the bile duct via the duodenal papilla. Keep Next, without inflating the balloon 3, a guide wire is inserted into the lumen 22a of the inner tube 22, and the balloon is inserted from the distal end side of the catheter tube 2 through the treatment instrument guide tube (channel) of the endoscope. A catheter 1 is inserted into the body.

Next, the distal end of the catheter tube 2 is viewed while viewing the image of the endoscope camera while viewing the distal end of the balloon catheter 1 protruding from the exit of the treatment guide tube at the tip (distal end) of the endoscope. Push to the desired position deep in the bile duct. Next, by using a syringe or the like, air is sent into the balloon 3 through the port 7b, the branch tube 7a, the air supply/exhaust passage 21a, and the air supply/exhaust hole 21b to inflate the balloon 3 and pull back the catheter tube 2 together with the endoscope. Then, the balloon 3 can scrape out the gallstone from the duodenal papilla to the outside of the bile duct. Gallstones scraped out of the bile duct are normally excreted out of the body naturally.

The calculus removal balloon catheter 1 of the embodiment described above uses a double-tube structure in which the inner tube 22 is inserted through the outer tube 21 as the catheter tube 2. The outer tube 21 is made of a relatively soft material with an emphasis on flexibility. Therefore, compared to conventional catheter tubes having a single tube structure, it is possible to achieve both the required rigidity and flexibility even when the diameter of the catheter tube is reduced. .

Contrary to the above, the inner tube 22 may be made of a relatively soft material with an emphasis on flexibility, and the outer tube 21 may be made of a relatively hard material with an emphasis on rigidity. , it is possible to achieve both the required stiffness and flexibility. However, if the inner tube 22 is made of a soft material, the lumen 22a of the inner tube 22 is deformed when it is bent. It may interfere with insertion. Therefore, as in the above-described embodiment, the inner tube 22 is made of a relatively hard material that emphasizes rigidity, while the outer tube 21 is made of a relatively soft material that emphasizes flexibility. It is better to use

In addition, since the tip 4 is provided as a separate member from the catheter tube 2, by using a tip made of a relatively soft material as the tip 4, the tip can be heated and compressed in the same manner as in the prior art. When inserting into a treatment instrument guide tube of a small-diameter endoscope, which may have a relatively large curvature, because the distal end (tip) can be made softer than in the case of giving a shape. Even so, it is possible to reduce interference with insertion.

Furthermore, by adhesively fixing the inner tube 22 to the inner tube mounting hole 42 and the outer tube 21 to the outer tube contact surface 43a, the distal end of the supply/exhaust passage 21a is airtightly closed. It is convenient because there is no need to provide a member or process for this.

In the above-described embodiment, the distal end of the outer tube 21 is adhesively fixed as the distal end 4 as shown in FIG. Although the distal end surface of the outer tube 21 is adhesively fixed to the outer tube contact surface 43a, a distal tip 4' having a configuration as shown in FIG. 5 can be used. That is, an outer tube mounting portion 43' having an outer tube contact surface 43a' is formed by cutting the outer periphery of the base end (proximal end) of the straight body portion 4a into a substantially annular shape. 43' may be inserted or press fit into the distal end of the lumen of outer tube 21 and adhesively secured together. In addition, in FIG. 5, the same reference numerals are given to substantially the same components as those shown in FIG. 4, and the description thereof will be omitted.

Moreover, as the distal tip 4, a tip configured as shown in FIG. 6 can also be used. That is, an outer tube mounting hole 43'' having an outer tube contact surface 43a'' is provided on the base end (proximal end) side of the inner tube mounting hole 42, and the outer tube 21 is inserted into the outer tube mounting hole 43''. The distal ends of the can be inserted or press fit to be adhesively secured together. If there is a step at the connecting portion between the distal end of the outer tube 21 and the proximal end of the distal tip 4, the catheter tube 2 may be caught when it is removed from the treatment instrument guide tube of the endoscope. It is preferable that a portion corresponding to the straight body portion 4a is formed into a thick tapered portion 4c so that a step is not formed. In FIG. 6, the same reference numerals are given to substantially the same components as those shown in FIG. 4, and the description thereof will be omitted.

In the above-described embodiment, a non-eccentric balloon that expands into a shape of revolution formed by rotating the outwardly convex curve of the catheter tube 2 around the axis of the catheter tube 2 as the rotation axis is used as the balloon 3 . As an example, instead of the balloon 3 shown in FIGS. 1 and 3, a balloon 3' is used as shown in FIGS. An eccentric balloon may also be provided. In FIGS. 7 and 8, substantially the same components as those shown in FIGS. 1 and 3 are denoted by the same numbers, and descriptions thereof are omitted.

The eccentric balloon 3' of the balloon catheter 1' of FIGS. 7 and 8 has the same basic configuration as the non-eccentric balloon 3 of the balloon catheter 1 of FIGS. A fixing tape 3d for fixing a part of the balloon 3' in the circumferential direction from above the balloon 3' to the catheter tube 2 along the longitudinal direction in order to inflate it eccentrically with respect to the axis of the is attached. The fixing tape 3 d is longer than the axial length of the balloon 3 ′, and both ends of the tape 3 d are fixed to the outer peripheral surface of the catheter tube 2 .

The material of the fixing tape 3 d is not particularly limited, and is composed of the same resin as the resin that constitutes the catheter tube 2 . A method for fixing both ends of the fixing tape 3d is not particularly limited, and examples thereof include adhesion, heat fusion, and high-frequency fusion. For example, in the case of the adhesion method, an adhesive (adhesive) is applied to the back surface of the tape 3d so as to adhere to a portion of the balloon 3' in the circumferential direction and a portion of the catheter tube 2.

The width of the fixing tape 3d is 1/2 or less of the circumferential length of the outer periphery of the catheter tube 2, preferably 1/3 to 1/5. If the width is too small, the function of fixing a part of the balloon 3' in the circumferential direction from above the balloon 3' to the catheter tube 2 will be reduced, and if the width is too large, the balloon 3' will be eccentric. Difficult to inflate.

Since such fixing tape 3d is attached, as shown in FIG. The eccentricity of the expansion center of the expansion portion with respect to the axis of the catheter tube 2 is preferably 50 to 100%, more preferably 75 to 100%, of the expansion radius of the expansion portion. It should be noted that the balloon 3' does not need to be inflated into a completely circular cross-section, and may be inflated into an elliptical or other shape.

In the above-described embodiment, the balloon catheter 1 has one balloon 3 or 3', but may have a plurality of balloons.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above-described embodiment is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1, 1'... Balloon catheter for stone removal 2... Catheter tube 21... Outer tube (outer tube)
21a: supply/exhaust path (supply/discharge path)
21b... Air supply/exhaust hole (supply/exhaust hole)
22... Inner tube (inner pipe)
22a... Lumen 3, 3'... Balloon 3a, 3b... Joining portion 3c, 3c'... Inflating portion 4, 4', 4''... Tip 4a... Straight body part 4b... Taper part 4c... Thick taper part 41 ... Bore 41a ... Tip opening 42 ... Inner tube mounting hole (inner tube mounting hole)
42a... Inner tube contact surface (inner tube contact surface)
43, 43', 43''... Outer tube mounting portion 43a, 43a', 43a''... Outer tube contact surface (outer tube contact surface)
5... Covers 6a, 7a... Branch pipes 6b, 7b... Ports

Claims (2)

a catheter tube having a double-tube structure, which includes an outer tube having supply and discharge holes penetrating inside and outside in the vicinity of the distal end thereof, and an inner tube inserted into the outer tube with a gap;
A supply/discharge path and the supply/discharge hole are provided on the outer periphery near the distal end of the outer tube so as to surround the supply/discharge hole, and are defined between the inner surface of the outer tube and the outer surface of the inner tube. a balloon that is inflated or deflated by supplying and discharging fluid to the inside through the balloon;
an inner tube mounting hole provided with an inner tube contact surface against which the distal end surface of the inner tube contacts when the distal end portion of the inner tube is inserted; and an inner tube mounted in the inner tube mounting hole. a substantially cylindrical tip having an outer tube abutting surface against which the distal end surface of the outer tube abuts;
the inner tube is made of a polymeric material selected from polyetheretherketone, polysulfone, polyethersulfone, and polyetherimide;
The outer tube is made of a polymeric material that is softer than the inner tube,
A calculus removal wherein the distal end of the outer tube and the distal end of the inner tube are fixed to the tip while the distal end of the supply and drainage channel is hermetically sealed by the tip. balloon catheter for. The balloon catheter for calculus removal according to claim 1 , wherein the outer tube has an outer diameter within the range of 0.6 to 2.5 mm.

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